Αρχειοθήκη ιστολογίου

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Πέμπτη 26 Μαΐου 2016

Information, Vol. 7, Pages 29: Measuring Knowledge Management Performance in Organizations: An Integrative Framework of Balanced Scorecard and Fuzzy Evaluation

As an important part of knowledge management (KM), the KM performance evaluation tries to find out the key factors restraining the enhancement of the enterprises' performance. This paper investigates the feasibility of the balanced scorecard (BSC) method in enterprise knowledge management and then proposes a simplified and applicable performance evaluation model based on the BSC approach. Finally, fuzzy comprehensive evaluation (FCE) is used to evaluate the effectiveness and applicability of the proposed model. The result shows that the model is useful for evaluating the performance of KM in enterprises.

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Remote Sensing, Vol. 8, Pages 449: MERIS Phytoplankton Time Series Products from the SW Iberian Peninsula (Sagres) Using Seasonal-Trend Decomposition Based on Loess

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The European Space Agency has acquired 10 years of data on the temporal and spatial distribution of phytoplankton biomass from the MEdium Resolution Imaging Spectrometer (MERIS) sensor for ocean color. The phytoplankton biomass was estimated with the MERIS product Algal Pigment Index 1 (API 1). Seasonal-Trend decomposition of time series based on Loess (STL) identified the temporal variability of the dynamical features in the MERIS products for water leaving reflectance (ρw(λ)) and API 1. The advantages of STL is that it can identify seasonal components changing over time, it is responsive to nonlinear trends, and it is robust in the presence of outliers. One of the novelties in this study is the development and the implementation of an automatic procedure, stl.fit(), that searches the best data modeling by varying the values of the smoothing parameters, and by selecting the model with the lowest error measure. This procedure was applied to 10 years of monthly time series from Sagres in the Southwestern Iberian Peninsula at three Stations, 2, 10 and 18 km from the shore. Decomposing the MERIS products into seasonal, trend and irregular components with stl.fit(), the ρw(λ) indicated dominance of the seasonal and irregular components while API 1 was mainly dominated by the seasonal component, with an increasing effect from inshore to offshore. A comparison of the seasonal components between the ρw(λ) and the API 1 product, showed that the variations decrease along this time period due to the changes in phytoplankton functional types. Furthermore, inter-annual seasonal variation for API 1 showed the influence of upwelling events and in which month of the year these occur at each of the three Sagres stations. The stl.fit() is a good tool for any remote sensing study of time series, particularly those addressing inter-annual variations. This procedure will be made available in R software.

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Energies, Vol. 9, Pages 411: Simultaneous Optimization of Topology and Component Sizes for Double Planetary Gear Hybrid Powertrains

Hybrid powertrain technologies are successful in the passenger car market and have been actively developed in recent years. Optimal topology selection, component sizing, and controls are required for competitive hybrid vehicles, as multiple goals must be considered simultaneously: fuel efficiency, emissions, performance, and cost. Most of the previous studies explored these three design dimensions separately. In this paper, two novel frameworks combining these three design dimensions together are presented and compared. One approach is nested optimization which searches through the whole design space exhaustively. The second approach is called enhanced iterative optimization, which executes the topology optimization and component sizing alternately. A case study shows that the later method can converge to the global optimal design generated from the nested optimization, and is much more computationally efficient. In addition, we also address a known issue of optimal designs: their sensitivity to parameters, such as varying vehicle weight, which is a concern especially for the design of hybrid buses. Therefore, the iterative optimization process is applied to design a robust multi-mode hybrid electric bus under different loading scenarios as the final design challenge of this paper.

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Metals, Vol. 6, Pages 127: The Effects of Al and Ti Additions on the Structural Stability, Mechanical and Electronic Properties of D8m-Structured Ta5Si3

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In the present study, the influence of substitutional elements (Ti and Al) on the structural stability, mechanical properties, electronic properties and Debye temperature of Ta5Si3 with a D8m structure were investigated by first principle calculations. The Ta5Si3 alloyed with Ti and Al shows negative values of formation enthalpies, indicating that these compounds are energetically stable. Based on the values of formation enthalpies, Ti exhibits a preferential occupying the Ta4b site and Al has a strong site preference for the Si8h site. From the values of the bulk modulus (B), shear modulus (G) and Young's modulus (E), we determined that both Ti and Al additions decrease both the shear deformation resistance and the elastic stiffness of D8m structured Ta5Si3. Using the shear modulus/bulk modulus ratio (G/B), Poisson's ratio (υ) and Cauchy's pressure, the effect of Ti and Al additions on the ductility of D8m-structured Ta5Si3 are explored. The results show that Ti and Al additions reduce the hardness, resulting in solid solution softening, but improve the ductility of D8m-structured Ta5Si3. The electronic calculations reveal that Ti and Al additions change hybridization between Ta-Si and Si-Si atoms for the binary D8m-structured Ta5Si3. The new Ta-Al bond is weaker than the Ta-Si covalent bonds, reducing the covalent property of bonding in D8m-structured Ta5Si3, while the new strong Ti4b-Ti4b anti-bonding enhances the metallic behavior of the binary D8m-structured Ta5Si3. The change in the nature of bonding can well explain the improved ductility of D8m-structured Ta5Si3 doped by Ti and Al. Moreover, the Debye temperatures, ΘD, of D8m-structured Ta5Si3 alloying with Ti and Al are decreased as compared to the binary Ta5Si3.

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Microarrays, Vol. 5, Pages 11: Living Cell Microarrays: An Overview of Concepts

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Living cell microarrays are a highly efficient cellular screening system. Due to the low number of cells required per spot, cell microarrays enable the use of primary and stem cells and provide resolution close to the single-cell level. Apart from a variety of conventional static designs, microfluidic microarray systems have also been established. An alternative format is a microarray consisting of three-dimensional cell constructs ranging from cell spheroids to cells encapsulated in hydrogel. These systems provide an in vivo-like microenvironment and are preferably used for the investigation of cellular physiology, cytotoxicity, and drug screening. Thus, many different high-tech microarray platforms are currently available. Disadvantages of many systems include their high cost, the requirement of specialized equipment for their manufacture, and the poor comparability of results between different platforms. In this article, we provide an overview of static, microfluidic, and 3D cell microarrays. In addition, we describe a simple method for the printing of living cell microarrays on modified microscope glass slides using standard DNA microarray equipment available in most laboratories. Applications in research and diagnostics are discussed, e.g., the selective and sensitive detection of biomarkers. Finally, we highlight current limitations and the future prospects of living cell microarrays.

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Aerospace, Vol. 3, Pages 15: Theoretical and Numerical Modeling of Acoustic Metamaterials for Aeroacoustic Applications

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The advent, during the first decade of the 21st century, of the concept of acoustic metamaterial has disclosed an incredible potential of development for breakthrough technologies. Unfortunately, the extension of the same concepts to aeroacoustics has turned out to be not a trivial task, because of the different structure of the governing equations, characterized by the presence of the background aerodynamic convection. Some of the approaches recently introduced to circumvent the problem are biased by a fundamental assumption that makes the actual realization of devices extremely unlikely: the metamaterial should guarantee an adapted background aerodynamic convection in order to modify suitably the acoustic field and obtain the desired effect, thus implying the porosity of the cloaking device. In the present paper, we propose an interpretation of the metamaterial design that removes this unlikely assumption, focusing on the identification of an aerodynamically-impermeable metamaterial capable of reproducing the surface impedance profile required to achieve the desired scattering abatement. The attention is focused on a moving obstacle impinged by an acoustic perturbation induced by a co-moving source. The problem is written in a frame of reference rigidly connected to the moving object to couple the convective wave equation in the hosting medium with the inertially-anisotropic wave operator within the cloak. The problem is recast in an integral form and numerically solved through a boundary-field element method. The matching of the local wave vector is used to derive a convective design of the metamaterial applicable to the specific problem analyzed. Preliminary numerical results obtained under the simplifying assumption of a uniform aerodynamic flow reveal a considerable enhancement of the masking capability of the convected design. The numerical method developed shows a remarkable computational efficiency, completing a simulation of the entire field in a few minutes on mid-end workstations. The results are re-interpreted in term of boundary impedance, assuming a locally-reacting behavior of the outer boundary of the cloaking layer. The formulation is currently being extended to the analysis of arbitrarily complex external flows in order to remove the limitation of the background uniform stream in the host.

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Universe, Vol. 2, Pages 8: Black Holes and Exotic Spinors

Exotic spin structures are non-trivial liftings, of the orthogonal bundle to the spin bundle, on orientable manifolds that admit spin structures according to the celebrated Geroch theorem. Exotic spin structures play a role of paramount importance in different areas of physics, from quantum field theory, in particular at Planck length scales, to gravity, and in cosmological scales. Here, we introduce an in-depth panorama in this field, providing black hole physics as the fount of spacetime exoticness. Black holes are then studied as the generators of a non-trivial topology that also can correspond to some inequivalent spin structure. Moreover, we investigate exotic spinor fields in this context and the way exotic spinor fields branch new physics. We also calculate the tunneling probability of exotic fermions across a Kerr-Sen black hole, showing that the exotic term does affect the tunneling probability, altering the black hole evaporation rate. Finally we show that it complies with the Hawking temperature universal law.

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Atmosphere, Vol. 7, Pages 75: Stratospheric Aerosols from Major Volcanic Eruptions: A Composition-Climate Model Study of the Aerosol Cloud Dispersal and e-folding Time

Large explosive volcanic eruptions are capable of injecting considerable amounts of particles and sulfur gases above the tropopause, causing large increases in stratospheric aerosols. Five major volcanic eruptions after 1960 (i.e., Agung, St. Helens, El Chichón, Nevado del Ruiz and Pinatubo) have been considered in a numerical study conducted with a composition-climate coupled model including an aerosol microphysics code for aerosol formation and growth. Model results are compared between an ensemble of numerical simulations including volcanic aerosols and their radiative effects (VE) and a reference simulations ensemble (REF) with no radiative impact of the volcanic aerosols. Differences of VE-REF show enhanced diabatic heating rates; increased stratospheric temperatures and mean zonal westerly winds; increased planetary wave amplitude; and tropical upwelling. The impact on stratospheric upwelling is found to be larger when the volcanically perturbed stratospheric aerosol is confined to the tropics, as tends to be the case for eruptions which were followed by several months with easterly shear of the quasi-biennial oscillation (QBO), e.g., the Pinatubo case. Compared to an eruption followed by a period of westerly QBO, such easterly QBO eruptions are quite different, with meridional transport to mid- and high-latitudes occurring later, and at higher altitude, with a consequent decrease in cross-tropopause removal from the stratosphere, and therefore longer decay timescale. Comparing the model-calculated e-folding time of the volcanic aerosol mass during the first year after the eruptions, an increase is found from 8.1 and 10.3 months for El Chichón and Agung (QBO westerly shear), to 14.6 and 30.7 months for Pinatubo and Ruiz (QBO easterly shear). The corresponding e-folding time of the global-mean radiative flux changes goes from 9.1 and 8.0 months for El Chichón and Agung, to 28.7 and 24.5 months for Pinatubo and Ruiz.

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IJMS, Vol. 17, Pages 809: The miRacle in Pancreatic Cancer by miRNAs: Tiny Angels or Devils in Disease Progression

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Pancreatic ductal adenocarcinoma (PDAC) is an aggressive malignancy with increasing incidence and high mortality. Surgical resection is the only potentially curative treatment of patients with PDAC. Because of the late presentation of the disease, about 20 percent of patients are candidates for this treatment. The average survival of resected patients is between 12 and 20 months, with a high probability of relapse. Standard chemo and radiation therapies do not offer significant improvement of the survival of these patients. Furthermore, novel treatment options aimed at targeting oncogenes or growth factors in pancreatic cancer have proved unsuccessful. Thereby, identifying new biomarkers that can detect early stages of this disease is of critical importance. Among these biomarkers, microRNAs (miRNAs) have supplied a profitable recourse and become an attractive focus of research in PDAC. MiRNAs regulate many genes involved in the development of PDAC through mRNA degradation or translation inhibition. The possibility of intervention in the molecular mechanisms of miRNAs regulation could begin a new generation of PDAC therapies. This review summarizes the reports describing miRNAs involvement in cellular processes involving pancreatic carcinogenesis and their utility in diagnosis, survival and therapeutic potential in pancreatic cancer.

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IFC(EDITORIAL BOARD)

Publication date: June 2016
Source:DNA Repair, Volume 42





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Potential Role of Epigenetic Mechanism in Manganese Induced Neurotoxicity

Manganese is a vital nutrient and is maintained at an optimal level (2.5–5 mg/day) in human body. Chronic exposure to manganese is associated with neurotoxicity and correlated with the development of various neurological disorders such as Parkinson's disease. Oxidative stress mediated apoptotic cell death has been well established mechanism in manganese induced toxicity. Oxidative stress has a potential to alter the epigenetic mechanism of gene regulation. Epigenetic insight of manganese neurotoxicity in context of its correlation with the development of parkinsonism is poorly understood. Parkinson's disease is characterized by the -synuclein aggregation in the form of Lewy bodies in neuronal cells. Recent findings illustrate that manganese can cause overexpression of -synuclein. -Synuclein acts epigenetically via interaction with histone proteins in regulating apoptosis. -Synuclein also causes global DNA hypomethylation through sequestration of DNA methyltransferase in cytoplasm. An individual genetic difference may also have an influence on epigenetic susceptibility to manganese neurotoxicity and the development of Parkinson's disease. This review presents the current state of findings in relation to role of epigenetic mechanism in manganese induced neurotoxicity, with a special emphasis on the development of Parkinson's disease.

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Fibers, Vol. 4, Pages 18: Glass Fibre Strength—A Review with Relation to Composite Recycling

The recovery and reuse of glass fibres from manufacturing waste and end-of-life composites in an environmentally-friendly, cost-effective manner is one of the most important challenges facing the thermosetting polymer composites industry. A number of processes for recycling fibres from such materials are available or under development. However, nearly all options deliver recycled glass fibres that are not cost-performance competitive due to the huge drop in strength of recycled glass fibre compared to its original state. A breakthrough in the regeneration of recycled glass fibre performance has the potential to totally transform the economics of recycling such composites. This paper reviews the available knowledge of the thermally-induced strength loss in glass fibres, discusses some of the phenomena that are potentially related and presents the status of research into processes to regenerate the strength and value of such weak recycled glass fibres.

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Sustainability, Vol. 8, Pages 502: The Environmental Impact and Cost Analysis of Concrete Mixing Blast Furnace Slag Containing Titanium Gypsum and Sludge in South Korea

This study assessed the environmental effects and cost of the Industrial Waste addictive Blast Furnace Slag (W-BFS) using Life Cycle Assessment (LCA) and compared it to general BFS. The environmental impacts of W-BFS were as follows: 1.12 × 10−1 kg-CO2 eq/kg, 3.18 × 10−5 kg-Ethylene eq/kg, 4.79 × 10−4 kg-SO2 eq/kg, 7.15 × 10−4 kg-PO43− eq/kg, 7.15 × 10−4 kg-CFC11 eq/kg and 3.94 × 10−3 kg-Antimony eq/kg. Among the environmental impact category, GWP and AP were 9.28 × 10−2 kg-CO2 eq/kg and 3.33 × 10−4 kg-SO2 eq/kg at a raw material stage, accounting for 80% and 70% of total environmental impact respectively. In EP, POCP and ADP, in addition, raw material stage accounted for a great portion in total environmental impact because of "W" among input materials. In ODP, however, compared to the environmental impact of raw materials, oil, which was used in transporting BFS to the W-BFS manufacturing factory, was more influential. In terms of GWP, POCP and ODP, W-BFS was higher than general BFS. In terms of AP, EP and ADP, in contrast, the former was lower than the latter. In terms of cost, W-BFS (41.7 US$/ton) was lower than general BFS by about 17% because of the use of waste additives comprised of industrial wastes instead of natural gypsum ,which has been commonly used in general BFS. In terms of GWP and POCP, the W-BFS mixed (30%) concrete was lower than plain concrete by 25%. In terms of AP and EP, the former was lower than the latter by 30%. In terms of ADP, furthermore, W-BFS mixed (30%) concrete was lower than plain concrete by 11%. In aggregate-related ODP, however, almost no change was found. In terms of cost, when W-BFS was added by 10% and 30%, it was able to reduce cost by 3% and 7% respectively, compared to plain concrete. Compared to BFS-mixed concrete as well, cost could be saved by 1% additionally because W-BFS (US$41.7/ton) is lower than common cement (US$100.3/ton) by about 60% in terms of production costs.

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Sustainability, Vol. 8, Pages 508: Impact of International Oil Price on Energy Conservation and Emission Reduction in China

In the context of "new normal" economy and frequent "haze", the strategy of energy conservation and emission reduction aiming to lower costs and reduce pollution is currently still a major strategic direction in China and the world, and will remain so for some time in the future. This paper uses the annual data of West Texas Intermediate (WTI) crude oil price in 1987–2014 as samples. We firstly present the direction and mechanism of the influence of oil price change on total consumption of every kind of energy by path analysis, and then consider establishing a Structural Vector Autoregression model of energy conservation and emission reduction in three statuses. Research shows that if the international oil price increases by 1%, the energy consumption per GDP and carbon dioxide emission increase by 0.092% and 0.053% respectively in the corresponding period. In the status of high energy consumption and high emission, if the international oil price increases by 1%, the energy consumption per GDP and carbon dioxide emission increase by 0.043% and 0.065% respectively in the corresponding period. In the status of low energy consumption and low emission, if the international oil price increases by 1%, the energy consumption per GDP per unit increases by 0.067% and carbon dioxide emission decreases by 0.085% in the corresponding period.

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IJERPH, Vol. 13, Pages 534: Dissipation and Residues of Dichlorprop-P and Bentazone in Wheat-Field Ecosystem

Dichlorprop-P and bentazone have been widely used in the prevention and control of weeds in wheat field ecosystems. There is a concern that pesticide residues and metabolites remain on or in the wheat. Thus, the study of the determination and monitoring of their residues in wheat has important significance. A rapid, simple and reliable QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) method was modified, developed and validated for the determination of dichlorprop-P, bentazone and its metabolites (6-hydroxy-bentazone and 8-hydroxy-bentazone) in wheat (wheat plants, wheat straw and grains of wheat) using high-performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS). The average recoveries of this method ranged from 72.9% to 108.7%, and the limits of quantification (LOQs) were 2.5–12 μg/kg. The dissipation and final residue of four compounds in three provinces (Shandong, Jiangsu and Heilongjiang) in China were studied. The trial results showed that the half-lives of dichlorprop-P and bentazone were 1.9–2.5 days and 0.5–2.4 days in wheat plants, respectively. The terminal residues in grains of wheat and wheat straw at harvest were all much below the maximum residue limit (MRL) of 0.2 mg/kg for dichlorprop-P and 0.1 mg/kg for bentazone established by the European Union (EU, Regulation No. 396/2005).

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Energies, Vol. 9, Pages 410: Development of a Novel Bidirectional DC/DC Converter Topology with High Voltage Conversion Ratio for Electric Vehicles and DC-Microgrids

The main objective of this paper was to study a bidirectional direct current to direct current converter (BDC) topology with a high voltage conversion ratio for electric vehicle (EV) batteries connected to a dc-microgrid system. In this study, an unregulated level converter (ULC) cascaded with a two-phase interleaved buck-boost charge-pump converter (IBCPC) is introduced to achieve a high conversion ratio with a simpler control circuit. In discharge state, the topology acts as a two-stage voltage-doubler boost converter to achieve high step-up conversion ratio (48 V to 385 V). In charge state, the converter acts as two cascaded voltage-divider buck converters to achieve high voltage step-down conversion ratio (385 V to 48 V). The features, operation principles, steady-state analysis, simulation and experimental results are made to verify the performance of the studied novel BDC. Finally, a 500 W rating prototype system is constructed for verifying the validity of the operation principle. Experimental results show that highest efficiencies of 96% and 95% can be achieved, respectively, in charge and discharge states.

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Sensors, Vol. 16, Pages 759: Computer-Aided Sensor Development Focused on Security Issues

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The paper examines intelligent sensor and sensor system development according to the Common Criteria methodology, which is the basic security assurance methodology for IT products and systems. The paper presents how the development process can be supported by software tools, design patterns and knowledge engineering. The automation of this process brings cost-, quality-, and time-related advantages, because the most difficult and most laborious activities are software-supported and the design reusability is growing. The paper includes a short introduction to the Common Criteria methodology and its sensor-related applications. In the experimental section the computer-supported and patterns-based IT security development process is presented using the example of an intelligent methane detection sensor. This process is supported by an ontology-based tool for security modeling and analyses. The verified and justified models are transferred straight to the security target specification representing security requirements for the IT product. The novelty of the paper is to provide a patterns-based and computer-aided methodology for the sensors development with a view to achieving their IT security assurance. The paper summarizes the validation experiment focused on this methodology adapted for the sensors system development, and presents directions of future research.

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Applied Sciences, Vol. 6, Pages 161: Isolation, Identification, and Biotransformation of Teadenol A from Solid State Fermentation of Pu-erh Tea and In Vitro Antioxidant Activity

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Post-fermented Pu-erh tea (PFPT) has several health benefits, however, little is known about the bioactive compounds. In this study, a PFPT compound was isolated by column chromatography and identified as Teadenol A by spectroscopic data analyses, including mass spectrometry and 1D and 2D NMR spectroscopy. Teadenol A in tea leaves was biotransformed by Aspergillus niger and A. tamari at 28 °C for 14 d at concentrations ranging from 9.85 ± 1.17 to 12.93 ± 0.38 mg/g. Additionally, the compound was detected in 22 commercial PFPTs at concentrations ranging from 0.17 ± 0.1 to 8.15 ± 0.1 mg/g. Teadenol A promoted the secretion of adiponectin and inhibited the expression of protein tyrosine phosphatase-1B. Antioxidant assays (e.g., 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging activity, total antioxidant capacity (T-AOC), hydrogen donating ability, and superoxide anion radical scavenging capacity) revealed that Teadenol A has antioxidant properties. Therefore, Teadenol A is an important bio-active component of PFPT.

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Energies, Vol. 9, Pages 412: Analytical Model for Voltage-Dependent Photo and Dark Currents in Bulk Heterojunction Organic Solar Cells

A physics-based explicit mathematical model for the external voltage-dependent forward dark current in bulk heterojunction (BHJ) organic solar cells is developed by considering Shockley-Read-Hall (SRH) recombination and solving the continuity equations for both electrons and holes. An analytical model for the external voltage-dependent photocurrent in BHJ organic solar cells is also proposed by incorporating exponential photon absorption, dissociation efficiency of bound electron-hole pairs (EHPs), carrier trapping, and carrier drift and diffusion in the photon absorption layer. Modified Braun's model is used to compute the electric field-dependent dissociation efficiency of the bound EHPs. The overall net current is calculated considering the actual solar spectrum. The mathematical models are verified by comparing the model calculations with various published experimental results. We analyze the effects of the contact properties, blend compositions, charge carrier transport properties (carrier mobility and lifetime), and cell design on the current-voltage characteristics. The power conversion efficiency of BHJ organic solar cells mostly depends on electron transport properties of the acceptor layer. The results of this paper indicate that improvement of charge carrier transport (both mobility and lifetime) and dissociation of bound EHPs in organic blend are critically important to increase the power conversion efficiency of the BHJ solar cells.

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JMSE, Vol. 4, Pages 37: Quantitative Estimates of Bio-Remodeling on Coastal Rock Surfaces

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Remodeling of rocky coasts and erosion rates have been widely studied in past years, but not all the involved processes acting over rocks surface have been quantitatively evaluated yet. The first goal of this paper is to revise the different methodologies employed in the quantification of the effect of biotic agents on rocks exposed to coastal morphologic agents, comparing their efficiency. Secondly, we focus on geological methods to assess and quantify bio-remodeling, presenting some case studies in an area of the Mediterranean Sea in which different geological methods, inspired from the revised literature, have been tested in order to provide a quantitative assessment of the effects some biological covers exert over rocky platforms in tidal and supra-tidal environments. In particular, different experimental designs based on Schmidt hammer test results have been applied in order to estimate rock hardness related to different orders of littoral platforms and the bio-erosive/bio-protective role of Chthamalus ssp. and Verrucariaadriatica. All data collected have been analyzed using statistical tests to evaluate the significance of the measures and methodologies. The effectiveness of this approach is analyzed, and its limits are highlighted. In order to overcome the latter, a strategy combining geological and experimental–computational approaches is proposed, potentially capable of revealing novel clues on bio-erosion dynamics. An experimental-computational proposal, to assess the indirect effects of the biofilm coverage of rocky shores, is presented in this paper, focusing on the shear forces exerted during hydration-dehydration cycles. The results of computational modeling can be compared to experimental evidence, from nanoscopic to macroscopic scales.

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Sustainability, Vol. 8, Pages 507: Quantitative Study on the Dynamic Mechanism of Smart Low-Carbon City Development in China

With the development of new generation technology and the low-carbon economy, the smart low-carbon city has become one of the academic hotspots. Many studies on it have begun; however, the dynamic mechanism is rarely involved. Therefore, this paper uses the Technique for Order Preference by Similarity to an Ideal Solution (TOPSIS) method to creatively take a quantitative study on a Chinese smart low-carbon city's dynamic mechanism. The results show that: (1) the three main dynamics of smart low-carbon city development in China are institutional and cultural conditions, facilities and functions conditions and economy and industry conditions, but the overall utility is relatively low; (2) the level of the dynamic operation mechanism of the Chinese smart low-carbon city is distinct between regions, indicating a diminishing spatial law from east to west and differences within regions; (3) the imbalance of the comprehensive dynamic mechanism and the operation status between smart low-carbon cities is prominent, showing a decreasing urban scale law of from big to small and differences within each scale, and a descending administration hierarchy law from high to low and differences within each class; (4) seven basic development patterns can be obtained, and most of the cities belong to the external strong/internal weak mode, which basically matches with its development realities. Finally, general policy recommendations and countermeasures of optimization and improvement are proposed.

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Algorithms, Vol. 9, Pages 36: Robust Hessian Locally Linear Embedding Techniques for High-Dimensional Data

Recently manifold learning has received extensive interest in the community of pattern recognition. Despite their appealing properties, most manifold learning algorithms are not robust in practical applications. In this paper, we address this problem in the context of the Hessian locally linear embedding (HLLE) algorithm and propose a more robust method, called RHLLE, which aims to be robust against both outliers and noise in the data. Specifically, we first propose a fast outlier detection method for high-dimensional datasets. Then, we employ a local smoothing method to reduce noise. Furthermore, we reformulate the original HLLE algorithm by using the truncation function from differentiable manifolds. In the reformulated framework, we explicitly introduce a weighted global functional to further reduce the undesirable effect of outliers and noise on the embedding result. Experiments on synthetic as well as real datasets demonstrate the effectiveness of our proposed algorithm.

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Risks, Vol. 4, Pages 16: Spouses’ Dependence across Generations and Pricing Impact on Reversionary Annuities

This paper studies the dependence between coupled lives, i.e., the spouses' dependence, across different generations, and its effects on prices of reversionary annuities in the presence of longevity risk. Longevity risk is represented via a stochastic mortality intensity. We find that a generation-based model is important, since spouses' dependence decreases when passing from older generations to younger generations. The independence assumption produces quantifiable mispricing of reversionary annuities, with different effects on different generations. The research is conducted using a well-known dataset of double life contracts.

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Tailored message interventions versus typical messages for increasing participation in colorectal cancer screening among a non-adherent population: A randomized controlled trial

BMC Public Health

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Haemorrhoidal artery ligation versus rubber band ligation for the management of symptomatic second-degree and third-degree haemorrhoids (HubBLe): a multicentre, open-label, randomised controlled trial

The Lancet

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Laparoscopic distal pancreatectomy for pancreatic tumors: Does size matter?

Digestive Surgery

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Statin-induced liver Injury in an area endemic for hepatitis B virus infection: Risk factors and outcome analysis

British Journal of Clinical Pharmacology

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Recurrence of solid pseudopapillary neoplasms of the pancreas: results of a nationwide study of risk factors and treatment modalities

Pediatric Blood & Cancer

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The role of hepatitis E virus infection in Adult Americans with acute liver failure

Hepatology

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Postinfectious and sporadic functional gastrointestinal disorders have different prevalences and rates of overlap: Results from a controlled cohort study 3 years after acute giardiasis

Neurogastroenterology & Motility

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Age-dependent characteristics of feedback evaluation related to monetary gains and losses

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Publication date: Available online 25 May 2016
Source:International Journal of Psychophysiology
Author(s): Zsófia Kardos, Brigitta Tóth, Roland Boha, Bálint File, Márk Molnár
Monitoring the consequences of actions is of crucial importance in order to optimize behavior to the challenges of the environment. Recently the age-related aspects of this fundamentally important cognitive processing have been brought into the focus of investigation since behavioral monitoring and related control mechanisms are widely known to be affected by aging. Processing of feedback stimuli is a core mechanism for rapid evaluation of the functionally significant aspects of outcome, guiding behavior towards avoidance or approach. The aim of the present study was to analyze the age-related alterations in the most prominent electrophysiological correlates of feedback processing, the feedback-related negativity (FRN) and the P3 event-related potential components, using a two-choice-single-outcome gambling task with two amounts of monetary stakes. In terms of behavioral indices higher proportion of risky choices was observed after loss than after gain events in both groups. In the young the FRN component was found to be an indicator of the goodness of outcome (loss or gain), and the P3 showed a complex picture of feedback evaluation with selective sensitivity to large amount of gain. In contrast, in the elderly group outcome valence had no effect on the amplitude of the FRN, and the P3 was also insensitive of the complex outcome properties. As the ERP-correlates of feedback processing are not as pronounced in the elderly, it is suggested that normal aging is accompanied by an alteration of the neural mechanisms signaling the most salient feedback stimulus properties.



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IJMS, Vol. 17, Pages 378: A Theoretical Study of the Hydration of Methane, from the Aqueous Solution to the sI Hydrate-Liquid Water-Gas Coexistence

Monte Carlo and molecular dynamics simulations were done with three recent water models TIP4P/2005 (Transferable Intermolecular Potential with 4 Points/2005), TIP4P/Ice (Transferable Intermolecular Potential with 4 Points/ Ice) and TIP4Q (Transferable Intermolecular Potential with 4 charges) combined with two models for methane: an all-atom one OPLS-AA (Optimal Parametrization for the Liquid State) and a united-atom one (UA); a correction for the C–O interaction was applied to the latter and used in a third set of simulations. The models were validated by comparison to experimental values of the free energy of hydration at 280, 300, 330 and 370 K, all under a pressure of 1 bar, and to the experimental radial distribution functions at 277, 283 and 291 K, under a pressure of 145 bar. Regardless of the combination rules used for σC,O, good agreement was found, except when the correction to the UA model was applied. Thus, further simulations of the sI hydrate were performed with the united-atom model to compare the thermal expansivity to the experiment. A final set of simulations was done with the UA methane model and the three water models, to study the sI hydrate-liquid water-gas coexistence at 80, 230 and 400 bar. The melting temperatures were compared to the experimental values. The results show the need to perform simulations with various different models to attain a reliable and robust molecular image of the systems of interest.

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Radiologic and Clinicopathologic Findings of Inflammatory Myofibroblastic Tumor.

Purpose: The aim of the study was to describe the clinical, radiographic, and pathologic features of inflammatory myofibroblastic tumor (IMT) to enhance the recognition of this rare disease. Materials and Methods: The clinical, imaging, and pathologic findings were retrospectively reviewed in 54 patients with IMT lesions, which were conformed by biopsy or surgical pathology. Of 54 patients, 51 had preoperative computed tomography (CT) examination and 13 had preoperative magnetic resonance imaging records. Results: The clinical appearances of these 54 patients had some relationship with the locations of lesions. Of 54 IMT patients, 87.0% cases (47/54) had solitary lesion. The mean long diameter of the lesions located at the sites of chest, abdomen, and pelvic regions was bigger than that of other locations (F = 3.025, P = 0.038). On plain CT images, soft tissue mass was found in all IMT lesions, except for 3 lesions that arose in the intestine tract, appearing as focal or diffuse thickening in the bowel wall. After contrast administration, all lesions were persistently enhanced; 72.7% cases (24/33) demonstrated heterogeneous enhancement with various cystic regions. Comparing the CT features with different anatomic lesions, ill-defined margin on the plain CT images and calcification were seen more frequently in the lesions of the head and neck (P = 0.010 and 0.035); however, the other radiological findings had no significant differences (all P > 0.05). Twelve of 51 IMT patients showed invasion into adjacent structures. On magnetic resonance imaging, 92.3% lesions (12/13) showed soft tissue masses demonstrating isointense to hypointense contrast compared with skeletal muscle on T1-weighted images and heterogeneously high signals on T2-weighted images; 85.7%(6/7) of lesions were heterogeneously enhanced with cystic changes. Immunohistochemistry showed that the percentage of positive staining for SMA, vimentin, anaplastic lymphoma kinase, CD68, CD34, CD99, B-cell lymphoma/leukemia-2, cytokeratin, Desmin, and S-100 protein were 88.9%, 87.0%, 44.4%, 59.3%, 53.7%, 29.6%, 42.6%, 28.5%, 13.0%, and 24.1%, respectively. Conclusions: Inflammatory myofibroblastic tumor can involve any part of the body, and the clinical and radiological appearances are various owing to different anatomic sites. An ill-defined soft tissue mass heterogeneous enhancement with or without invasion into adjacent structures on computed tomographic or magnetic resonance images and positive staining for SMA and vimentin on immunohistochemical examination could suggest the diagnosis. Copyright (C) 2016 Wolters Kluwer Health, Inc. All rights reserved.

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Lesion Size and Iodine Quantification to Distinguish Low-Grade From High-Grade Clear Cell Renal Cell Carcinoma Using Dual-Energy Spectral Computed Tomography.

Objective: The aim of this study was to assess the utility of lesion size and iodine quantification using dual-energy spectral computed tomography to distinguish between low-grade and high-grade clear cell renal cell carcinomas (ccRCCs). Methods: Spectral parameters of 75 patients with pathologically proven ccRCCs who underwent preoperative dual-energy spectral computed tomography examinations were divided into low-grade and high-grade groups. Independent sample t test, receiver operating characteristic curve analysis, and Spearman rank correlation were analyzed. Results: The lesion size was significantly smaller, and spectral parameters were significantly higher in the low-grade ccRCC. The significant correlation (r = -0.412, P

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Low-Contrast and Low-Radiation Dose Protocol in Cardiac Computed Tomography: Usefulness of Low Tube Voltage and Knowledge-Based Iterative Model Reconstruction Algorithm.

Objective: This study aimed to evaluate the feasibility of a low contrast, low-radiation dose protocol of 80-peak kilovoltage (kVp) with prospective electrocardiography-gated cardiac computed tomography (CT) using knowledge-based iterative model reconstruction (IMR). Methods: Thirty patients underwent an 80-kVp prospective electrocardiography-gated cardiac CT with low-contrast agent (222-mg iodine per kilogram of body weight) dose. We also enrolled 30 consecutive patients who were scanned with a 120-kVp cardiac CT with filtered back projection using the standard contrast agent dose (370-mg iodine per kilogram of body weight) as a historical control group. We evaluated the radiation dose for the 2 groups. The 80-kVp images were reconstructed with filtered back projection (protocol A), hybrid iterative reconstruction (HIR, protocol B), and IMR (protocol C). We compared CT numbers, image noise, and contrast-to-noise ratio among 120-kVp protocol, protocol A, protocol B, and protocol C. In addition, we compared the noise reduction rate between HIR and IMR. Two independent readers compared image contrast, image noise, image sharpness, unfamiliar image texture, and overall image quality among the 4 protocols. Results: The estimated effective dose (ED) of the 80-kVp protocol was 74% lower than that of the 120-kVp protocol (1.4 vs 5.4 mSv). The contrast-to-noise ratio of protocol C was significantly higher than that of protocol A. The noise reduction rate of IMR was significantly higher than that of HIR (P

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Multivariate Analysis of Pleural Invasion of Peripheral Non-Small Cell Lung Cancer-Based Computed Tomography Features.

Objective: The aim of this study was to comprehensively analyze computed tomography features to improve the diagnostic accuracy of visceral pleural invasion of peripheral non-small cell lung cancer. Methods: The computed tomography features of 205 non-small cell lung cancer patients were retrospectively studied. The lesion's relation to the pleura was classified into 5 grades. A multivariate logistic regression analysis was conducted to identify independent factors predicting pleural invasion. Results: The multivariate logistic regression analysis showed that sex (odds ratio [OR], 1.822; P = 0.080), pleural indentation (OR, 4.111; P

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Dual-Energy CT Characteristics of Parathyroid Adenomas on 25- and 55-Second 4D-CT Acquisitions: Preliminary Experience.

Objective: The objective of this study was to compare the dual-energy computed tomography (CT) characteristics of parathyroid adenomas (PAs), thyroid tissue, and lymph nodes (LNs) and assess whether the spectral information can improve distinction of these tissues. Methods: Dual-energy CT scans from 20 patients with pathologically proven PAs were retrospectively evaluated, identifying 19 eligible PAs and region of interest analysis used for spectral characterization. Results: There was a significant difference in multiple spectral parameters between PAs, LNs, and the thyroid gland (P

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Accelerated Brain Atrophy on Serial Computed Tomography: Potential Marker of the Progression of Alzheimer Disease.

Objective: The aim of this study was to validate computed tomography (CT)-based longitudinal markers of the progression of Alzheimer disease (AD). Materials and Methods: We retrospectively studied 33 AD patients and 39 nondemented patients with other neurological illnesses (non-AD) having 4 to 12 CT examinations of the head, with over a mean (SD) of 3.9 (1.7) years. At each time point, we applied an automatic software to measure whole brain, cerebrospinal fluid, and intracranial space volumes. Longitudinal measures were then related to disease status and time since the first scan using hierarchical models. Results: Absolute brain volume loss accelerated for non-AD patients by 0.86 mL/y2 (95% confidence interval [CI], 0.64-1.08 mL/y2) and 1.5x faster, that is, 1.32 mL/y2 (95% CI, 1.09-1.56 mL/y2) for AD patients (P = 0.006). In terms of brain volume normalized to intracranial space, the acceleration in atrophy rate for non-AD patients was 0.0578%/y2 (95% CI, 0.0389%/y2 to 0.0767%/y2), again 1.5x faster, that is, 0.0919%/y2 (95% CI, 0.0716%/y2 to 0.1122%/y2) for AD patients (P = 0.017). This translates to an increase in atrophy rate from 0.5% to 1.4% in AD versus to 1.1% in non-AD group after 10 years. Conclusions: Brain volumetry on CT reliably detected accelerated volume loss in AD and significantly lower acceleration factor in age-matched non-AD patients, leading to the possibility of its use to monitor the progression of cognitive decline and dementia. Copyright (C) 2016 Wolters Kluwer Health, Inc. All rights reserved.

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The Initial Exploration of Adamkiewicz Artery Computed Tomographic Angiography With Monochromatic Reconstruction of Gemstone Spectral Imaging.

Objective: The study aimed to explore whether optimal monochromatic reconstruction can improve the depiction of the Adamkiewicz artery (AKA) on gemstone spectral computed tomographic angiography (GSCTA) compared with the polychromatic reconstruction protocol. Methods: The prospective study was approved by the ethics committee, and written informed consent was obtained from each patient. The 58 consecutive patients suspected of aortic aneurysm or dissection underwent aortic GSCTA. All images were reconstructed with both polychromatic (group A) and optimal monochromatic (group B) protocol. The CT values of the descending aorta and muscle, background noise, and the contrast-to-noise ratio were measured and calculated. With the criterion standard display of AKA, characteristic hairpin curve sign, 2 blinded radiologists analyzed data independently with the paired samples t, [chi]2, and Mann-Whitney U test. Results: The CT value of the descending aorta and the contrast-to-noise ratio of group B were significantly superior to group A (t = 12.7, P

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A Liver Phantom Study: CT Radiation Dose Reduction and Different Image Reconstruction Algorithms Affect Diagnostic Quality.

Objective: The aim of this study was to evaluate whether iterative reconstruction techniques for different dose levels and/or reduction of tube potential can increase liver lesion detectability. Methods: An anthropomorphic liver phantom was scanned at different dose levels (CTDIvol 15 mGy, 7.5 mGy, 5 mGy, and 2.6 mGy) and tube potential levels (120 kV, 100 kV, and 80 kV). Images were reconstructed with the following algorithms: filtered back projection (FBP), adaptive statistical iterative reconstruction (ASiR) 40%, and a model-based iterative reconstruction (Veo). The presence or absence of lesions was assessed independently on a 4-point scale by 4 readers. The areas under the receiver operating characteristic curve were calculated. Results: Veo improved detectability of hyperdense liver lesions compared with both FBP and ASiR 40% at most dose levels (15 mGy, 7.5 mGy, and 5 mGy with P

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Computed Tomography Perfusion of Prostate Cancer: Diagnostic Value of Quantitative Analysis.

Objective: The aim of the study was to assess the diagnostic value of computed tomography perfusion (CTp) of prostate in distinguishing between normal tissue and malignant lesion by using quantitative threshold values of CTp parameters. Materials and Methods: Sixty-one consecutive men with indication for radical prostatectomy were prospectively enrolled. All patients were intravenously injected with 80-mL bolus of nonionic iodinated contrast medium during cine-mode acquisition protocol. Perfusion data sets were analyzed by a dedicated software system and values for each of the 4 CTp parameters (blood volume, blood flow, mean transit time, and permeability surface-area product measurements) were recorded. Receiver operating characteristic curves were calculated to find which CTp parameter and which cutoff value might reveal the best diagnostic accuracy. Histopathology was used as reference standard. Results: Statistical correlation between radiological and pathological results was performed on 48 patients using 3456 segmented squares. Blood volume and permeability surface revealed the best diagnostic accuracy for differentiating between malignant and benign squares, with cutoff values of 6.1 and 16.5, respectively, and a sensitivity of 84.8% and 81.8%, respectively. All parameters showed also a high negative predictive value: 97.1% for blood volume and 95.4% for permeability surface. Conclusions: Blood volume and permeability surface are the 2 CTp parameters with the highest diagnostic accuracy in differentiating between normal tissue and prostatic neoplasia. Due to the extremely high negative predictive value, they are particularly valuable in excluding the presence of cancer and thus resulting potentially useful in assessing cancer response to adjuvant therapy. Copyright (C) 2016 Wolters Kluwer Health, Inc. All rights reserved.

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Apparent Diffusion Coefficient and Dynamic Contrast-Enhanced Magnetic Resonance Imaging in Pancreatic Cancer: Characteristics and Correlation With Histopathologic Parameters.

Objective: To clarify diffusion and perfusion abnormalities and evaluate correlation between apparent diffusion coefficient (ADC), MR perfusion and histopathologic parameters of pancreatic cancer (PC). Methods: Eighteen patients with PC underwent diffusion-weighted imaging and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI). Parameters of DCE-MRI and ADC of cancer and non-cancerous tissue were compared. Correlation between the rate constant that represents transfer of contrast agent from the arterial blood into the extravascular extracellular space (Ktrans), volume of the extravascular extracellular space per unit volume of tissue (Ve), and ADC of PC and histopathologic parameters were analyzed. Results: The rate constant that represents transfer of contrast agent from the extravascular extracellular space into blood plasma, Ktrans, tissue volume fraction occupied by vascular space, and ADC of PC were significantly lower than nontumoral pancreases. Ve of PC was significantly higher than that of nontumoral pancreas. Apparent diffusion coefficient and Ktrans values of PC were negatively correlated to fibrosis content and fibroblast activation protein staining score. Fibrosis content was positively correlated to Ve. Conclusion: Apparent diffusion coefficient values and parameters of DCE-MRI can differentiate PC from nontumoral pancreases. There are correlations between ADC, Ktrans, Ve, and fibrosis content of PC. Fibroblast activation protein staining score of PC is negatively correlated to ADC and Ktrans. Apparent diffusion coefficient, Ktrans, and Ve may be feasible to predict prognosis of PC. Copyright (C) 2016 Wolters Kluwer Health, Inc. All rights reserved.

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Primary Extremity Liposarcoma: MRI Features, Histopathology, and Clinical Outcomes.

Objective: This study aimed to describe magnetic resonance imaging (MRI) features of extremity liposarcoma (LPS) subtypes, correlating with histopathology and clinical outcomes. Methods: In this retrospective study, we included 125 patients (80 men, 45 women; mean age, 53 years) with extremity LPS [23 atypical lipomatous tumor (ALT), 9 dedifferentiated (DDLPS), 70 myxoid (MLPS), 23 pleomorphic (PLPS)]. Pretreatment MRI of primary tumors in 56 patients (10 ALT, 4 DDLPS, 28 MLPS, 14 PLPS) was reviewed. Results: All subtypes were predominantly T1 isointense relative to skeletal muscle (DDLPS = 3/4, MLPS = 28/28, PLPS = 13/14) and T2 hyperintense (ALT = 10/10, DDLPS = 3/4, MLPS = 28/28, PLPS = 14/14) except for ALT which were T1 hyperintense (8/10). Within MLPS, high grade was associated with unencapsulated margins (P = 0.05) and solid, nodular enhancement (P

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Beak-Like Extension of the Pancreatic Uncinate Process on MDCT: Is It Hyperplasia or Movement?.

Objective: We aimed to evaluate the pancreatic uncinate process with a beak-like extension (BLE) beyond the left border of the superior mesenteric artery, to define the cause of BLE, and to differentiate BLE from hyperplasia. Methods: We retrospectively reviewed 1042 triple-phase contrast-enhanced multidetector-row computed tomography (3P-CE-MDCT) examinations of 500 patients. Finally, 38 patients (28 men, 10 women; mean age, 66 years) with 140 3P-CE-MDCT images showing BLE were studied regarding BLE size, contour, and cause. The superior mesenteric artery position was also evaluated. Results: Beak-like extensions were found in 7.6% of patients. Most were caused by movement of the small bowel mesentery (n = 21, 55%), with deviation of mesenteric vessels or mass effect from expanded adjacent organs (n = 3, 8%). Seven patients (18.5%) had true hyperplasia. Conclusions: Beak-like extension is caused by movement of the small bowel mesentery with deviation of mesenteric vessels or by adjacent organ expansion. Beak-like extension closely mimics other pathology on nonenhanced MDCT. Copyright (C) 2016 Wolters Kluwer Health, Inc. All rights reserved.

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Retrospective Assessment of Histogram-Based Diffusion Metrics for Differentiating Benign and Malignant Endometrial Lesions.

Objective: Our study aimed to retrospectively evaluate the utility of volumetric histogram-based diffusion metrics in differentiating benign from malignant endometrial abnormalities. Methods: A total of 54 patients underwent pelvic magnetic resonance imaging with diffusion-weighted imaging before endometrial tissue diagnosis. Two radiologists placed volumes of interest on the apparent diffusion coefficient (ADC) map encompassing the entire endometrium and focal endometrial lesions. The mean ADC, percentile ADC values, kurtosis, skewness, and entropy of ADC were compared between benign and malignant abnormalities. Results: In premenopausal patients, significant independent predictors of malignancy were whole-endometrium analysis for R1, 10th to 25th ADC percentile (P = 0.012); whole-endometrium analysis for R2, mean ADC (P = 0.001) and skewness (P = 0.004); focal lesion analysis for R1, skewness (P = 0.045); focal lesion analysis for R2, 10th to 25th ADC percentile (P

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Evaluation of Lung Radiofrequency Ablation With Dual-Energy Computed Tomography: Analysis of Tumor Composition and Lung Perfusion.

Objective: The aim of this study was to evaluate radiofrequency ablation (RFA) of lung tumors with dual-energy computed tomography while focusing on tumor composition and lung perfusion. Methods: The 36 tumors in 25 patients were included. Dual-energy computed tomography was performed before RFA and at 2 days and 1, 3, and 6 months thereafter. The effective atomic number (Zeff) of the tumors before RFA was compared with the Zeff at each follow-up using the paired t test. Lung perfusion was evaluated by iodine map images. When decreased perfusion was suspected after RFA, lung perfusion scintigraphy was performed. Results: The mean Zeff of the tumors significantly (P

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Iterative Reconstruction Results in Larger Computed Tomography Measurements of Iliofemoral Artery Diameter in Patients Referred for Transcatheter Aortic Valve Replacement.

Objectives: We hypothesized that improved iterative reconstruction increases image quality and reduces artifacts for iliofemoral artery computed tomography imaging in patients referred for transcatheter aortic valve replacement (TAVR). Methods: We examined 56 consecutive patients undergoing computed tomography for possible TAVR and compared image quality and iliofemoral artery size between adaptive statistical iterative reconstructions (ASIRs) and improved model-based iterative reconstructions (MBIRs). Results: Model-based iterative reconstruction (vs ASIR) was associated with improved (P

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Symmetry, Vol. 8, Pages 39: A PT -Symmetric Dual-Core System with the Sine-Gordon Nonlinearity and Derivative Coupling

As an extension of the class of nonlinear PT -symmetric models, we propose a system of sine-Gordon equations, with the PT symmetry represented by balanced gain and loss in them. The equations are coupled by sine-field terms and first-order derivatives. The sinusoidal coupling stems from local interaction between adjacent particles in coupled Frenkel–Kontorova (FK) chains, while the cross-derivative coupling, which was not considered before, is induced by three-particle interactions, provided that the particles in the parallel FK chains move in different directions. Nonlinear modes are then studied in this system. In particular, kink-kink (KK) and kink-anti-kink (KA) complexes are explored by means of analytical and numerical methods. It is predicted analytically and confirmed numerically that the complexes are unstable for one sign of the sinusoidal coupling and stable for another. Stability regions are delineated in the underlying parameter space. Unstable complexes split into free kinks and anti-kinks that may propagate or become quiescent, depending on whether they are subject to gain or loss, respectively.

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Microsatellite instability as a predictive factor for immunotherapy in malignant melanoma

Publication date: August 2016
Source:Medical Hypotheses, Volume 93
Author(s): Ondrej Kubecek, Petronela Trojanova, Veronika Molnarova, Jindrich Kopecky
Immunotherapy has attracted attention as a novel treatment modality for malignant melanoma. Although the use of immunotherapy in metastatic melanoma has shown promising results, there remains a lack of predictive biomarkers indicating treatment benefit from immunotherapy. There is growing evidence suggesting that microsatellite instability (MSI) as a product of DNA mismatch repair deficiency, may be one of possible predictive markers in malignant melanoma. It has been proposed that the immunogenicity of some tumors might be determined by mutational heterogeneity and could be the key to the success of immune therapies. This is also supported by the fact that tumors with the highest amount of somatic mutations, such as malignant melanoma have showed positive results with immune checkpoint inhibitors. There are promising data regarding the association between MSI status and immunogenicity from studies with colorectal cancer, where MSI is linked to improved prognosis compared to microsatellite stable cancers. MSI in colon cancer is linked to a significant increase of immunocompetent cells responsible for the antitumor activity – CD3+, CD8+, CD45RO+, and T-bet+ lymphocytes and decrease of inhibition factors such as Foxp3, IL-6, IL-17, and TGF-β. On the other hand, taking into account the progression-dependent accumulation of somatic mutations in MSI tumors and consequent high levels of neo-antigens, the possible drug resistance of MSI tumors to traditional treatment, and the presence of inhibition checkpoints within the MSI tumors, there is a solid rationale for the use of novel therapeutic strategies such as immunotherapy in MSI melanomas. We presume that the MSI phenotype in malignant melanoma might be helpful to identify patients, who would be more likely to profit from immunotherapy than from conventional therapy.



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Targeting the ecology within: The role of the gut–brain axis and human microbiota in drug addiction

Publication date: August 2016
Source:Medical Hypotheses, Volume 93
Author(s): Patrick D. Skosnik, Jose A. Cortes-Briones
Despite major advances in our understanding of the brain using traditional neuroscience, reliable and efficacious treatments for drug addiction have remained elusive. Hence, the time has come to utilize novel approaches, particularly those drawing upon contemporary advances in fields outside of established neuroscience and psychiatry. Put another way, the time has come for a paradigm shift in the addiction sciences.Apropos, a revolution in the area of human health is underway, which is occurring at the nexus between enteric microbiology and neuroscience. It has become increasingly clear that the human microbiota (the vast ecology of bacteria residing within the human organism), plays an important role in health and disease. This is not surprising, as it has been estimated that bacteria living in the human body (approximately 1kg of mass, roughly equivalent to that of the human brain) outnumber human cells 10 to 1. While advances in the understanding of the role of microbiota in other areas of human health have yielded intriguing results (e.g., Clostridium difficile, irritable bowel syndrome, autism, etc.), to date, no systematic programs of research have examined the role of microbiota in drug addiction.The current hypothesis, therefore, is that gut dysbiosis plays a key role in addictive disorders. In the context of this hypothesis, this paper provides a rationale for future research to target the "gut–brain axis" in addiction. A brief background of the gut–brain axis is provided, along with a series of hypothesis-driven ideas outlining potential treatments for addiction via manipulations of the "ecology within."



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