Αρχειοθήκη ιστολογίου

Αναζήτηση αυτού του ιστολογίου

Παρασκευή 19 Αυγούστου 2016

Inventions, Vol. 1, Pages 15: Optimal Design and Control of a z-Tilt Piezoelectric Based Nano-Scale Compensation Stage with Circular Flexure Hinges

The Taguchi method is widely used for the optimization of mechanical design and this study is used it in the design of a 2D circular flexure hinge for a z-tilt piezoelectric based nano-scale compensation stage. Maximum displacement of the stage is 16 μm at z-axis and ±30 arcsec at θx and θy. The most important design parameters for such a flexure hinge are minimal diameter, body height, and notch radius. The important requirements for the optimal design of a flexure hinge is that the z-tilt stage should have the highest possible natural frequency and the smallest coupling displacement. Simulation results show the nano-stage to have a higher natural frequency (626 Hz) and lower coupling displacement (0.032%). A kinematic model for the z-tilt stage has also been proposed in this study and the experimental results show the actual natural frequency of 510 Hz to be slightly lower than in the simulation. By keeping the angular displacement less than ±30 arcsec for z-tilt motion of the stage, the results of tracking experiments show a coupling displacement of 300 nm for the z-axis and 1 arcsec for θx while the θy tracked a sine wave of 1 Hz and an amplitude of 5 arcsec.

http://ift.tt/2bOmqnx

Sustainability, Vol. 8, Pages 814: Novel Role of Rural Official Organization in the Biomass-Based Power Supply Chain in China: A Combined Game Theory and Agent-Based Simulation Approach

Developing biomass-based power generation is helpful for China to reduce the dependence on fossil fuels and to release the targets of carbon emission peak. The decentralized farming method leads to Chinese farmers' weak willingness to collect and sell crop residues to biomass-based power plants. The purpose of this paper is to solve the issue by proposing a novel biomass feedstock supply model with China's rural official organization—villagers' committee, which has great influence on villagers' decision making. Introducing it into the biomass-based power supply chain is beneficial to motivating farmers' supplying enthusiasm. A combined game theory and agent-based simulation approach is applied to study the effectiveness of this new supply model. Multiple simulation scenarios are built to study impacts of different simulation parameters, and results show that farmers tend to supply more biomass material for electricity production in the proposed villagers' committee model, compared with the two conventional supply models, direct-deal and broker models. The supply model incorporating the rural official organization can ensure the feedstock sufficiency for plants. A proper model design depends on the feed-in tariff subsidy for biomass-based electricity, feedstock shipping distance, performance appraisal system of the villagers' committee, as well as farmers' utility weights on net income and public service improvement.

http://ift.tt/2bCj0kt

Forests, Vol. 7, Pages 176: Cellulose Dynamics during Foliar Litter Decomposition in an Alpine Forest Meta-Ecosystem

To investigate the dynamics and relative drivers of cellulose degradation during litter decomposition, a field experiment was conducted in three individual ecosystems (i.e., forest floor, stream, and riparian zone) of an alpine forest meta-ecosystem on the eastern Tibetan Plateau. Four litter species (i.e., willow: Salix paraplesia, azalea: Rhododendron lapponicum, cypress: Sabina saltuaria, and larch: Larix mastersiana) that had varying initial litter chemical traits were placed separately in litterbags and then incubated on the soil surface of forest floor plots or in the water of the stream and riparian zone plots. Litterbags were retrieved five times each year during the two-year experiment, with nine replicates each time for each treatment. The results suggested that foliar litter lost 32.2%–89.2% of the initial dry mass depending on litter species and ecosystem type after two-year's incubation. The cellulose lost 60.1%–96.8% of the initial mass with degradation rate in the order of stream > riparian zone > forest floor. Substantial cellulose degradation occurred at the very beginning (i.e., in the first pre-freezing period) of litter decomposition. Litter initial concentrations of phosphorus (P) and lignin were found to be the dominant chemical traits controlling cellulose degradation regardless of ecosystems type. The local-scale environmental factors such as temperature, pH, and nutrient availability were important moderators of cellulose degradation rate. Although the effects of common litter chemical traits (e.g., P and lignin concentrations) on cellulose degradation across different individual ecosystems were identified, local-scale environmental factors such as temperature and nutrient availability were found to be of great importance for cellulose degradation. These results indicated that local-scale environmental factors should be considered apart from litter quality for generating a reliable predictive framework for the drivers of cellulose degradation and further on litter decomposition at a global scale.

http://ift.tt/2bOmgMQ

Sensors, Vol. 16, Pages 1318: CS2-Collector: A New Approach for Data Collection in Wireless Sensor Networks Based on Two-Dimensional Compressive Sensing

In this paper, we consider the problem of reconstructing the temporal and spatial profile of some physical phenomena monitored by large-scale Wireless Sensor Networks (WSNs) in an energy efficient manner. Compressive sensing is one of the popular choices to reduce the energy consumption of the data collection in WSNs. The existing solutions only consider sparsity of sensors' data from either temporal or spatial dimensions. In this paper, we propose a novel data collection strategy, CS2-collector, for WSNs based on the theory of Two Dimensional Compressive Sensing (2DCS). It exploits both temporal and spatial sparsity, i.e., 2D-sparsity of WSNs and achieves significant gain on the tradeoff between the compression ratio and reconstruction accuracy as the numerical simulations and evaluations on different types of sensors' data. More intuitively, with the same given energy budget, CS2-collector provides significantly more accurate reconstruction of the profile of the physical phenomena that are temporal-spatially sparse.

http://ift.tt/2bChQpd

A simple dietary questionnaire correlates with formal dietitian evaluation and frequently identifies specific clinical interventions in an outpatient gastroenterology clinic

Journal of Clinical Gastroenterology

http://ift.tt/2b4amsc

Diabetes mellitus heightens the risk of hepatocellular carcinoma except in patients with hepatitis C cirrhosis

The American Journal of Gastroenterology

http://ift.tt/2b5BUR2

Obesity and Insulin Resistance Screening Tools in American Adolescents: National Health and Nutrition Examination Survey (NHANES) 1999 to 2010

Canadian Journal of Diabetes

http://ift.tt/2b4acAY

Modified FOLFOX6 with or without radiation versus fluorouracil and leucovorin with radiation in neoadjuvant treatment of locally advanced rectal cancer: initial results of the chinese FOWARC multicenter, open-label, randomized three-arm phase III trial

Journal of Clinical Oncology

http://ift.tt/2b5AxSG

Altered expression of a two-pore domain (K2P) mechano-gated potassium channel TREK-1 in Hirschsprung’s disease

Pediatric Research

http://ift.tt/2b4akRa

Sofosbuvir and ledipasvir for 8 weeks for the treatment of chronic hepatitis C virus infection in HCV-mono-infected and HIV-HCV co-infected individuals - results from the German hepatitis C cohort (GECCO-01)

Clinical Infectious Diseases

http://ift.tt/2b5BU3u

The LMS and Z scale growth reference for Saudi school-age children and adolescents

Saudi Journal of Gastroenterology

http://ift.tt/2b4alo8

Genome-wide association studies in oesophageal adenocarcinoma and Barrett's oesophagus: a large-scale meta-analysis

The Lancet Oncology

http://ift.tt/2b5Abve

WHipple-ABACUS, a simple, validated risk score for 30-day mortality after pancreaticoduodenectomy developed using the ACS-NSQIP database

Surgery

http://ift.tt/2b4aJDi

Repeat treatment with rifaximin is safe and effective in patients with diarrhea-predominant irritable bowel syndrome

Gastroenterology

http://ift.tt/2b5BiuR

PTEN loss is associated with a poor response to trastuzumab in HER2-overexpressing gastroesophageal adenocarcinoma

Gastric Cancer

http://ift.tt/2b49P9R

The gastrointestinal benefits of COX-2 selective inhibitors with concomitant use of low-dose aspirin

Alimentary Pharmacology and Therapeutics

http://ift.tt/2b5BbPY

Thioguanine in inflammatory bowel disease: Long-term efficacy and safety

United European Gastroenterology Journal

http://ift.tt/2b4bo7w

Risk factors and clinical characteristics of the depressive state induced by pegylated interferon therapy in patients with hepatitis c virus infection: a prospective study

Psychiatry and Clinical Neurosciences

http://ift.tt/2b5AA0B

Nonmalignant gastric causes of acute abdominal pain on MDCT: A pictorial review

Abdominal Imaging

http://ift.tt/2b4b3lr

Prospective study of serum cysteine and cysteinylglycine and cancer of the head and neck, esophagus, and stomach in a cohort of male smokers

American Journal of Clinical Nutrition

http://ift.tt/2b5BfiF

POEM is a cost-effective procedure: Cost-utility analysis of endoscopic and surgical treatment options in the management of achalasia

Surgical Endoscopy

http://ift.tt/2b4agko

Zinc as a possible preventive and therapeutic agent in pancreatic, prostate, and breast cancer

European Journal of Cancer Prevention

http://ift.tt/2b5At5u

Prospective assessment of the quality of life in patients treated surgically for rectal cancer with lower anterior resection and abdominoperineal resection

European Journal of Surgical Oncology

http://ift.tt/2b4anMF

No evidence that azathioprine increases risk of cholangiocarcinoma in patients with primary sclerosing cholangitis

Clinical Gastroenterology and Hepatology

http://ift.tt/2b3p9cQ

Nutrients, Vol. 8, Pages 509: Assessment of the Dietary Intake of Schoolchildren in South Africa: 15 Years after the First National Study

There has not been a national dietary study in children in South Africa since 1999. Fortification of flour and maize meal became mandatory in October 2003 to address micronutrient deficiencies found in the national study in 1999. The purpose of this review was to identify studies done after 1999 in schoolchildren, 6–15 years old, in order to determine whether dietary intakes reflected improvements in micronutrients, namely: iron, zinc, vitamin A, folate, thiamine, riboflavin, vitamin B6, and niacin. An electronic and hand search was done to identify all studies complying with relevant inclusion criteria. The search yielded 10 studies. Overall, there is a paucity of dietary studies which have included the fortified nutrients; only four, of which only one, reported on all micronutrients; making it difficult to determine whether fortification has improved the micronutrient intake of schoolchildren. This is further complicated by the fact that different dietary methods were used and that studies were only done in three of the nine provinces and thus are not generalizable. The results of these studies clearly point to the importance of doing a national study on the dietary intake of schoolchildren in order to confirm the outcomes of the fortification process.

http://ift.tt/2b2lfzt

Viruses, Vol. 8, Pages 235: The Host RNAs in Retroviral Particles

As they assemble, retroviruses encapsidate both their genomic RNAs and several types of host RNA. Whereas limited amounts of messenger RNA (mRNA) are detectable within virion populations, the predominant classes of encapsidated host RNAs do not encode proteins, but instead include endogenous retroelements and several classes of non-coding RNA (ncRNA), some of which are packaged in significant molar excess to the viral genome. Surprisingly, although the most abundant host RNAs in retroviruses are also abundant in cells, unusual forms of these RNAs are packaged preferentially, suggesting that these RNAs are recruited early in their biogenesis: before associating with their cognate protein partners, and/or from transient or rare RNA populations. These RNAs' packaging determinants differ from the viral genome's, and several of the abundantly packaged host ncRNAs serve cells as the scaffolds of ribonucleoprotein particles. Because virion assembly is equally efficient whether or not genomic RNA is available, yet RNA appears critical to the structural integrity of retroviral particles, it seems possible that the selectively encapsidated host ncRNAs might play roles in assembly. Indeed, some host ncRNAs appear to act during replication, as some transfer RNA (tRNA) species may contribute to nuclear import of human immunodeficiency virus 1 (HIV-1) reverse transcription complexes, and other tRNA interactions with the viral Gag protein aid correct trafficking to plasma membrane assembly sites. However, despite high conservation of packaging for certain host RNAs, replication roles for most of these selectively encapsidated RNAs—if any—have remained elusive.

http://ift.tt/2bCeXEC

Viruses, Vol. 8, Pages 233: Quantification of HEV RNA by Droplet Digital PCR

The sensitivity of real-time PCR for hepatitis E virus (HEV) RNA quantification differs greatly among techniques. Standardized tools that measure the real quantity of virus are needed. We assessed the performance of a reverse transcription droplet digital PCR (RT-ddPCR) assay that gives absolute quantities of HEV RNA. Analytical and clinical validation was done on HEV genotypes 1, 3 and 4, and was based on open reading frame (ORF)3 amplification. The within-run and between-run reproducibilities were very good, the analytical sensitivity was 80 HEV RNA international units (IU)/mL and linearities of HEV genotype 1, 3 and 4 were very similar. Clinical validation based on 45 samples of genotype 1, 3 or 4 gave results that correlated well with a validated reverse transcription quantitative PCR (RT-qPCR) assay (Spearman rs = 0.89, p < 0.0001). The RT-ddPCR assay is a sensitive method and could be a promising tool for standardizing HEV RNA quantification in various sample types.

http://ift.tt/2b2lJpp

Materials, Vol. 9, Pages 705: Addendum: Bassan, J.C.; et al. Immobilization of Trypsin in Lignocellulosic Waste Material to Produce Peptides with Bioactive Potential from Whey Protein. Materials 2016, 9(5), 357

The authors would like to add the following sentence to the "Acknowledgments" section of their article [1]:[...]

http://ift.tt/2bCf1V3

Dentistry Journal, Vol. 4, Pages 28: Advantages and Disadvantages of Bone Protective Agents in Metastatic Prostate Cancer: Lessons Learned

Nine out of ten metastatic prostate cancer (PCa) patients will develop osseous metastases. Of these, every second will suffer from skeletal-related events (SRE). SRE are associated with an increased risk for death, which is markedly increased in the presence of pathological fracture. Moreover, health insurance costs nearly double in the presence of SRE. Zoledronic acid and denosumab are both approved drugs for the prevention or delay of SRE in castration-resistant prostate cancer (CRPC) patients with osseous metastases. However, long-term treatment with one of these two drugs is associated with the development of medication-related osteonecrosis of the jaw (MRONJ). Routine inspections of the oral cavity before and during treatment are mandatory in these patients. Regarding imaging techniques, bone scintigraphy seems to be a promising tool to detect early stage MRONJ. Zoledronic acid does not reduce the incidence of SRE in hormone-sensitive PCa. First data shows 3-monthly application of zoledronic acid to be equi-effective to monthly application.

http://ift.tt/2b2kiHF

Healthcare, Vol. 4, Pages 58: The Relationship between Pain Beliefs and Physical and Mental Health Outcome Measures in Chronic Low Back Pain: Direct and Indirect Effects

Low back pain remains a major health problem with huge societal cost. Biomedical models fail to explain the disability seen in response to reported back pain and therefore patients' beliefs, cognitions and related behaviours have become a focus for both research and practice. This study used the Pain Beliefs Questionnaire and had two aims: To examine the extent to which pain beliefs are related to disability, anxiety and depression; and to assess whether those relationships are mediated by pain self-efficacy and locus of control. In a sample of 341 chronic low back pain patients, organic and psychological pain beliefs were related to disability, anxiety and depression. However, organic pain beliefs were more strongly related to disability and depression than psychological pain beliefs. Regression analyses revealed that these relationships were in part independent of pain self-efficacy and locus of control. Further, mediation analyses revealed indirect pathways involving self-efficacy and, to a lesser extent chance locus of control, between organic pain beliefs, on the one hand, and disability, anxiety and depression, on the other. In contrast, psychological pain beliefs were only directly related to disability, anxiety and depression. Although longitudinal data are needed to corroborate our findings, this study illustrates the importance of beliefs about the nature of pain and beliefs in one's ability to cope with pain in determining both physical and mental health outcomes in chronic low back pain patients.

http://ift.tt/2bCefHn

Energies, Vol. 9, Pages 659: Effect on Particulate and Gas Emissions by Combusting Biodiesel Blend Fuels Made from Different Plant Oil Feedstocks in a Liquid Fuel Burner

This paper focuses on the combustion performance of various blends of biodiesel fuels and diesel fuel from lean to rich mixtures. The biodiesel blend fuel combustion experiments were carried out using a liquid fuel burner and biodiesel fuel made from various plant oil feedstocks, including jatropha, palm and coconut oils. The results show that jatropha oil methyl ester blend 25 (JOME B25) and coconut oil methyl ester blend 25 (COME B25) blended at 25% by volume in diesel fuel produced lower carbon monoxide (CO) and unburned hydrocarbon (UHC) emissions due to more complete combustion. Overall, JOME B25 had the highest CO emission reduction, at about 42.25%, followed by COME B25 at 26.44% emission reduction relative to pure diesel fuel. By contrast, the palm oil methyl ester blend 25 (POME B25) showed a 48.44% increase in these emissions. The results showed that the nitrogen oxides (NOx) emissions were slightly higher for all biodiesel blend fuels compared with pure diesel fuel combustion. In case of sulphur dioxide (SO2) and UHC emissions, all biodiesel blends fuels have significantly reduced emissions. In the case of SO2 emission, the POME B25, JOME B25 and COME B25 emissions were reduced 14.62%, 14.45% and 21.39%, respectively, relative to SO2 emission from combusting pure diesel fuel. UHC emissions of POME B25, JOME B25 and COME B25 showed 51%, 71% and 70% reductions, respectively, compared to diesel fuel. The conclusion from the results is that all the biodiesel blend fuels are suitable and can be recommended for use in liquid fuel burners in order to get better and 'greener' environmental outcomes.

http://ift.tt/2b2k9E4

Nutrients, Vol. 8, Pages 507: Post-Intake of S-Ethyl Cysteine and S-Methyl Cysteine Improved LPS-Induced Acute Lung Injury in Mice

The effects of S-ethyl cysteine (SEC) and S-methyl cysteine (SMC) on lipopolysaccharide (LPS)-induced acute lung injury in mice were examined. Eight hours after LPS challenge, SEC or SMC was supplied in drinking water at 0.5% or 1% for 3 days. LPS increased lung myeloperoxidase activity, neutrophil counts and edema. SEC or SMC post-intake attenuated these events. SEC or SMC suppressed LPS-induced lung expression of cyclooxygenase-2, nuclear factor-κB and mitogen-activated protein kinase, and lowered the generation of tumor necrosis factor-alpha, monocyte chemoattractant protein-1 and prostaglandin E2. LPS enhanced the expression of p47phox, gp91phox, Bax and cleaved caspase-3, and increased the production of reactive oxygen species in the lung. SEC or SMC post-intake reversed these alterations. These findings suggest that these agents could protect the lung through their anti-inflammatory, anti-oxidative and anti-apoptotic activities.

http://ift.tt/2bCf0QZ

At the interface of stem cell research and new technologies

Content List – Read more articles from the symposium: Human models and technology for regenerative medicine.



http://ift.tt/2bs5669

Issue Information - Editorial Board



http://ift.tt/2bs53Y1

SYMPOSIUM: Human models and technology for regenerative medicine



http://ift.tt/2bCk2w7

Brain repair and reprogramming: the route to clinical translation

Abstract

The adult brain has a very limited capacity for generation of new neurons, and neurogenesis only takes place in restricted regions. Some evidence for neurogenesis after injury has been reported, but few, if any, neurons are replaced after brain injury or degeneration, and the permanent loss of neurons leads to long-term disability and loss of brain function. For decades, researchers have been developing cell transplantation using exogenous cell sources for brain repair, and this method has now been shown to successfully restore lost function in experimental and clinical trials. Here, we review the development of cell-replacement strategies for brain repair in Parkinson's disease using the example of human foetal brain cells being successfully translated from preclinical findings to clinical trials. These trials demonstrate that cell-replacement therapy is a viable option for patients with Parkinson's disease, but more importantly also show how the limited availability of foetal cells calls for development of novel cell sources and methods for generating new neurons for brain repair. We focus on new stem cell sources that are on the threshold of clinical application for brain repair and discuss emerging cellular reprogramming technologies. Reviewing the current status of direct neural conversion, both in vitro and in vivo, where somatic cells are directly reprogrammed into functional neurons without passing through a stem cell intermediate, we conclude that both methods result in the successful replacement of new neurons that mature and integrate into the host brain. Thus, this new field shows great promise for future brain repair, although much work is still needed in preclinical animal models before it can be seriously considered for clinical applications.



http://ift.tt/2bs5yB5

IJMS, Vol. 17, Pages 1354: Trichostatin A Enhances the Apoptotic Potential of Palladium Nanoparticles in Human Cervical Cancer Cells

scifeed_large.png

Cervical cancer ranks seventh overall among all types of cancer in women. Although several treatments, including radiation, surgery and chemotherapy, are available to eradicate or reduce the size of cancer, many cancers eventually relapse. Thus, it is essential to identify possible alternative therapeutic approaches for cancer. We sought to identify alternative and effective therapeutic approaches, by first synthesizing palladium nanoparticles (PdNPs), using a novel biomolecule called saponin. The synthesized PdNPs were characterized by several analytical techniques. They were significantly spherical in shape, with an average size of 5 nm. Recently, PdNPs gained much interest in various therapies of cancer cells. Similarly, histone deacetylase inhibitors are known to play a vital role in anti-proliferative activity, gene expression, cell cycle arrest, differentiation and apoptosis in various cancer cells. Therefore, we selected trichostatin A (TSA) and PdNPs and studied their combined effect on apoptosis in cervical cancer cells. Cells treated with either TSA or PdNPs showed a dose-dependent effect on cell viability. The combinatorial effect, tested with 50 nM TSA and 50 nMPdNPs, had a more dramatic inhibitory effect on cell viability, than either TSA or PdNPs alone. The combination of TSA and PdNPs had a more pronounced effect on cytotoxicity, oxidative stress, mitochondrial membrane potential (MMP), caspase-3/9 activity and expression of pro- and anti-apoptotic genes. Our data show a strong synergistic interaction between TSA and PdNPs in cervical cancer cells. The combinatorial treatment increased the therapeutic potential and demonstrated relevant targeted therapy for cervical cancer. Furthermore, we provide the first evidence for the combinatory effect and cytotoxicity mechanism of TSA and PdNPs in cervical cancer cells.

http://ift.tt/2bqJwjy

IJMS, Vol. 17, Pages 1359: Growth Hormone Releasing Peptide-2 Attenuation of Protein Kinase C-Induced Inflammation in Human Ovarian Granulosa Cells

scifeed_large.png

Cyclooxygenase-2 (COX-2) and interleukin-8 (IL-8) are two important inflammatory mediators in ovulation. Ghrelin may modulate inflammatory signaling via growth hormone secretagogue receptors. We investigated the role of ghrelin in KGN human ovarian granulosa cells using protein kinase C (PKC) activator phorbol 12, 13-didecanoate (PDD) and synthetic ghrelin analog growth hormone releasing peptide-2 (GHRP-2). GHRP-2 attenuated PDD-induced expression of protein and mRNA, the promoter activity of COX-2 and IL-8 genes, and the secretion of prostaglandin E2 (PGE2) and IL-8. GHRP-2 promoted the degradation of PDD-induced COX-2 and IL-8 proteins with the involvement of proteasomal and lysosomal pathways. PDD-mediated COX-2 production acts via the p38, c-Jun N-terminal kinase (JNK), extracellular signal-regulated kinase (ERK) and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) pathways; PDD-mediated IL-8 production acts via the p38, JNK and ERK pathways. GHRP-2 reduced the PDD-induced phosphorylation of p38 and JNK and activator protein 1 (AP-1) reporter activation and PDD-induced NF-κB nuclear translocation and reporter activation. The inhibitors of mitogen-activated protein kinase phosphatase-1 (MKP-1) and protein phosphatase 2 (PP2A) reduced the inhibitory effect of GHRP-2 on PDD-induced COX-2 and IL-8 expression. Our findings demonstrate an anti-inflammatory role for ghrelin (GHRP-2) in PKC-mediated inflammation of granulosa cells, at least in part, due to its inhibitory effect on PKC-induced activation of p38, JNK and NF-κB, possibly by targeting to MKP-1 and PP2A.

http://ift.tt/2b8w1l8

Metals, Vol. 6, Pages 192: Leaching Kinetics of Zinc from Metal Oxide Varistors (MOVs) with Sulfuric Acid

The leaching kinetics of zinc from zinc oxide-based metal oxide varistors (MOVs) was investigated in H2SO4 at atmospheric pressure. Kinetics experiments were carried out at various agitation speeds, particle sizes, initial H2SO4 concentrations, and reaction temperatures. It was determined that the leaching rate of zinc was independent of agitation speed above 300 rpm and also independent of particle size below 105 μm, whereas it dramatically increased with an increasing H2SO4 concentration. Except for when the H2SO4 concentration was varied, the m-values were almost constant at varying agitation speeds (m-values: 0.554–0.579), particle sizes (m-values: 0.507–0.560) and reaction temperature (m-values: 0.530–0.560) conditions. All of the m-values in these experiments were found to be below 0.580. Therefore, it is proposed that the extraction of zinc is a diffusion-controlled reaction. The leaching kinetics followed the D3 kinetic equation with a rate-controlling diffusion step through the ash layers, and the corresponding apparent activation energy was calculated as 20.7 kJ/mol in the temperature range of 313 K to 353 K.

http://ift.tt/2b436fS

Genes, Vol. 7, Pages 51: Targeting DNA Replication Stress for Cancer Therapy

The human cellular genome is under constant stress from extrinsic and intrinsic factors, which can lead to DNA damage and defective replication. In normal cells, DNA damage response (DDR) mediated by various checkpoints will either activate the DNA repair system or induce cellular apoptosis/senescence, therefore maintaining overall genomic integrity. Cancer cells, however, due to constitutive growth signaling and defective DDR, may exhibit "replication stress" —a phenomenon unique to cancer cells that is described as the perturbation of error-free DNA replication and slow-down of DNA synthesis. Although replication stress has been proven to induce genomic instability and tumorigenesis, recent studies have counterintuitively shown that enhancing replicative stress through further loosening of the remaining checkpoints in cancer cells to induce their catastrophic failure of proliferation may provide an alternative therapeutic approach. In this review, we discuss the rationale to enhance replicative stress in cancer cells, past approaches using traditional radiation and chemotherapy, and emerging approaches targeting the signaling cascades induced by DNA damage. We also summarize current clinical trials exploring these strategies and propose future research directions including the use of combination therapies, and the identification of potential new targets and biomarkers to track and predict treatment responses to targeting DNA replication stress.

http://ift.tt/2bqMl3W

Sensors, Vol. 16, Pages 1321: Modeling and Analysis of Micro-Spacecraft Attitude Sensing with Gyrowheel

This paper proposes two kinds of approaches of angular rate sensing for micro-spacecraft with a gyrowheel (GW), which can combine attitude sensing with attitude control into one single device to achieve a compact micro-spacecraft design. In this implementation, during the three-dimensional attitude control torques being produced, two-dimensional spacecraft angular rates can be sensed from the signals of the GW sensors, such as the currents of the torque coils, the tilt angles of the rotor, the motor rotation, etc. This paper focuses on the problems of the angular rate sensing with the GW at large tilt angles of the rotor. For this purpose, a novel real-time linearization approach based on Lyapunov's linearization theory is proposed, and a GW linearized measurement model at arbitrary tilt angles of the rotor is derived. Furthermore, by representing the two-dimensional rotor tilt angles and tilt control torques as complex quantities and separating the twice periodic terms about the motor spin speed, the linearized measurement model at smaller tilt angles of the rotor is given and simplified. According to the respective characteristics, the application schemes of the two measurement models are analyzed from the engineering perspective. Finally, the simulation results are presented to demonstrate the effectiveness of the proposed strategy.

http://ift.tt/2b43Em1

Energies, Vol. 9, Pages 643: Land Suitability Analysis for Solar Farms Exploitation Using GIS and Fuzzy Analytic Hierarchy Process (FAHP)—A Case Study of Iran

Considering the geographical location and climatic conditions of Iran, solar energy can provide a considerable portion of the energy demand for the country. This study develops a two-step framework. In the first step, the map of unsuitable regions is extracted based on the defined constraints. In the next step, in order to identify the suitability of different regions, 11 defined criteria, including solar radiation, average annual temperatures, distance from power transmission lines, distance from major roads, distance from residential area, elevation, slope, land use, average annual cloudy days, average annual humidity and average annual dusty days, are identified. The relative weights of defined criteria and sub-criteria are also determined applying fuzzy analytical hierarchy process (FAHP) technique. Next, by overlaying these criteria layers, the final map of prioritization of different regions of Iran for exploiting solar photovoltaic (PV) plants is developed. Based on Iran's political divisions, investigation and analysis of the results have been presented for a total of 1057 districts of the country, where each district stands in one of the five defined classes of excellent, good, fair, low, and poor level. The obtained data indicate that 14.7% (237,920 km2), 17.2% (278,270 km2), 19.2% (311,767 km2), 11.3% (183,057 km2), 1.8% (30,549 km2) and 35.8% (580,264 km2) of Iran's area are positioned as excellent, good, fair, low, poor and unsuitable areas, respectively. Moreover, Kerman, Yazd, Fars, Sisitan and Baluchestan, Southern Khorasan and Isfahan are included in the regions as the most excellent suitable provinces for exploiting solar PV plants.

http://ift.tt/2bqLNLz

Sensors, Vol. 16, Pages 1325: A Hybrid Vehicle Detection Method Based on Viola-Jones and HOG + SVM from UAV Images

A new hybrid vehicle detection scheme which integrates the Viola-Jones (V-J) and linear SVM classifier with HOG feature (HOG + SVM) methods is proposed for vehicle detection from low-altitude unmanned aerial vehicle (UAV) images. As both V-J and HOG + SVM are sensitive to on-road vehicles' in-plane rotation, the proposed scheme first adopts a roadway orientation adjustment method, which rotates each UAV image to align the roads with the horizontal direction so the original V-J or HOG + SVM method can be directly applied to achieve fast detection and high accuracy. To address the issue of descending detection speed for V-J and HOG + SVM, the proposed scheme further develops an adaptive switching strategy which sophistically integrates V-J and HOG + SVM methods based on their different descending trends of detection speed to improve detection efficiency. A comprehensive evaluation shows that the switching strategy, combined with the road orientation adjustment method, can significantly improve the efficiency and effectiveness of the vehicle detection from UAV images. The results also show that the proposed vehicle detection method is competitive compared with other existing vehicle detection methods. Furthermore, since the proposed vehicle detection method can be performed on videos captured from moving UAV platforms without the need of image registration or additional road database, it has great potentials of field applications. Future research will be focusing on expanding the current method for detecting other transportation modes such as buses, trucks, motors, bicycles, and pedestrians.

http://ift.tt/2b43U4B

Genes, Vol. 7, Pages 52: Remodeling and Control of Homologous Recombination by DNA Helicases and Translocases that Target Recombinases and Synapsis

Recombinase enzymes catalyse invasion of single-stranded DNA (ssDNA) into homologous duplex DNA forming "Displacement loops" (D-loops), a process called synapsis. This triggers homologous recombination (HR), which can follow several possible paths to underpin DNA repair and restart of blocked and collapsed DNA replication forks. Therefore, synapsis can be a checkpoint for controlling whether or not, how far, and by which pathway, HR proceeds to overcome an obstacle or break in a replication fork. Synapsis can be antagonized by limiting access of a recombinase to ssDNA and by dissociation of D-loops or heteroduplex formed by synapsis. Antagonists include DNA helicases and translocases that are identifiable in eukaryotes, bacteria and archaea, and which target synaptic and pre-synaptic DNA structures thereby controlling HR at early stages. Here we survey these events with emphasis on enabling DNA replication to be resumed from sites of blockage or collapse. We also note how knowledge of anti-recombination activities could be useful to improve efficiency of CRISPR-based genome editing.

http://ift.tt/2bqJ6tq

Energies, Vol. 9, Pages 662: Potential of Reversible Solid Oxide Cells as Electricity Storage System

Electrical energy storage (EES) systems allow shifting the time of electric power generation from that of consumption, and they are expected to play a major role in future electric grids where the share of intermittent renewable energy systems (RES), and especially solar and wind power plants, is planned to increase. No commercially available technology complies with all the required specifications for an efficient and reliable EES system. Reversible solid oxide cells (ReSOC) working in both fuel cell and electrolysis modes could be a cost effective and highly efficient EES, but are not yet ready for the market. In fact, using the system in fuel cell mode produces high temperature heat that can be recovered during electrolysis, when a heat source is necessary. Before ReSOCs can be used as EES systems, many problems have to be solved. This paper presents a new ReSOC concept, where the thermal energy produced during fuel cell mode is stored as sensible or latent heat, respectively, in a high density and high specific heat material and in a phase change material (PCM) and used during electrolysis operation. The study of two different storage concepts is performed using a lumped parameters ReSOC stack model coupled with a suitable balance of plant. The optimal roundtrip efficiency calculated for both of the configurations studied is not far from 70% and results from a trade-off between the stack roundtrip efficiency and the energy consumed by the auxiliary power systems.

http://ift.tt/2b8wGD2

Viruses, Vol. 8, Pages 230: Inoculation of Goats, Sheep, and Horses with MERS-CoV Does Not Result in Productive Viral Shedding

The Middle East respiratory syndrome coronavirus (MERS-CoV) was first recognized in 2012 and can cause severe disease in infected humans. Dromedary camels are the reservoir for the virus, although, other than nasal discharge, these animals do not display any overt clinical disease. Data from in vitro experiments suggest that other livestock such as sheep, goats, and horses might also contribute to viral transmission, although field data has not identified any seropositive animals. In order to understand if these animals could be infected, we challenged young goats and horses and adult sheep with MERS-CoV by intranasal inoculation. Minimal or no virus shedding was detected in all of the animals. During the four weeks following inoculation, neutralizing antibodies were detected in the young goats, but not in sheep or horses.

http://ift.tt/2bqJxnv

IJMS, Vol. 17, Pages 1359: Growth Hormone Releasing Peptide-2 Attenuation of Protein Kinase C-Induced Inflammation in Human Ovarian Granulosa Cells

Cyclooxygenase-2 (COX-2) and interleukin-8 (IL-8) are two important inflammatory mediators in ovulation. Ghrelin may modulate inflammatory signaling via growth hormone secretagogue receptors. We investigated the role of ghrelin in KGN human ovarian granulosa cells using protein kinase C (PKC) activator phorbol 12, 13-didecanoate (PDD) and synthetic ghrelin analog growth hormone releasing peptide-2 (GHRP-2). GHRP-2 attenuated PDD-induced expression of protein and mRNA, the promoter activity of COX-2 and IL-8 genes, and the secretion of prostaglandin E2 (PGE2) and IL-8. GHRP-2 promoted the degradation of PDD-induced COX-2 and IL-8 proteins with the involvement of proteasomal and lysosomal pathways. PDD-mediated COX-2 production acts via the p38, c-Jun N-terminal kinase (JNK), extracellular signal-regulated kinase (ERK) and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) pathways; PDD-mediated IL-8 production acts via the p38, JNK and ERK pathways. GHRP-2 reduced the PDD-induced phosphorylation of p38 and JNK and activator protein 1 (AP-1) reporter activation and PDD-induced NF-κB nuclear translocation and reporter activation. The inhibitors of mitogen-activated protein kinase phosphatase-1 (MKP-1) and protein phosphatase 2 (PP2A) reduced the inhibitory effect of GHRP-2 on PDD-induced COX-2 and IL-8 expression. Our findings demonstrate an anti-inflammatory role for ghrelin (GHRP-2) in PKC-mediated inflammation of granulosa cells, at least in part, due to its inhibitory effect on PKC-induced activation of p38, JNK and NF-κB, possibly by targeting to MKP-1 and PP2A.

http://ift.tt/2b8w1l8

Water, Vol. 8, Pages 354: Quantitative Analysis of Groundwater Recharge in an Arid Area, Northwest China

The Mixing Cell Model (MCM) is a useful tool that can be applied to areas with limited hydrogeological data, such as arid areas in northwest China, to transform available groundwater hydrochemical data into quantitative information about an aquifer. In this study, we used the MCM to quantify water circulation in the study area and to analyze information such as the supply source composition and proportion of the confined aquifer, the main supply aquifer for local drinking water. The MCM simulation results showed that the confined aquifer in the study area is mainly recharged by leakage of water from the upper unconfined aquifer and lateral flow from the eastern and southern tablelands. Unconfined groundwater and lateral flow contributed to 67.69% and 32.31% of the recharge, respectively. The groundwater circulation model of the study area provided quantitative information about water circulation in different parts of the study area, represented by different cells known as A–F. The information from this model provides a scientific basis for the sustainable use and development of water resources in different parts of the study area.

http://ift.tt/2bqJuIs

Healthcare, Vol. 4, Pages 57: Associations between Unhealthy Diet and Lifestyle Behaviours and Increased Cardiovascular Disease Risk in Young Overweight and Obese Women

Unhealthy lifestyle behaviours are known modifiable risk factors for cardiovascular disease (CVD). This cross-sectional analysis aimed to describe lifestyle behaviours and CVD risk markers in young overweight and obese Australian women and explore associations between individual and combined lifestyle behaviours with CVD risk markers. Lifestyle behaviours assessed were diet quality, alcohol intake, physical activity, sitting time and smoking status, and were combined to generate a Healthy Lifestyle Score (HLS) (0–5). Objectively measured CVD risk markers were body mass index (BMI), %body fat, waist circumference, blood pressure, and plasma cholesterol and triglycerides. Analysis included 49 women aged 18–35 years, with BMI 25.0 to 34.9 kg/m2. The mean ± SD Australian Recommended Food Score was 33.5 ± 9.3 points, alcohol 3.3 ± 2.4 standard drinks/day, physical activity 207 ± 225 min/week and sitting time 578 ± 213 min/day. All participants were non-smokers. The proportion of participants outside normal reference ranges was 83.7% for waist circumference (n = 41), blood pressure 0% (n = 0), total cholesterol 26.2% (n = 11), HDL cholesterol 38.6% (n = 17), LDL cholesterol 22.7% (n = 10), and triglycerides 4.2% (n = 2). Physical activity was inversely associated with body fat (β = −0.011%, p = 0.005), diastolic blood pressure (β = −0.010 mmHg, p = 0.031) and waist circumference (β = −0.013 cm, p = 0.029). Most participants (59.2%, n = 29) had a HLS ≤ 2. No significant associations were found between HLS and CVD risk markers. Insufficient physical activity was the primary lifestyle factor associated with increased CVD risk markers, which suggests interventions targeting physical activity in young women may potentially improve cardiovascular health.

http://ift.tt/2b8wtQk

IJMS, Vol. 17, Pages 1354: Trichostatin A Enhances the Apoptotic Potential of Palladium Nanoparticles in Human Cervical Cancer Cells

Cervical cancer ranks seventh overall among all types of cancer in women. Although several treatments, including radiation, surgery and chemotherapy, are available to eradicate or reduce the size of cancer, many cancers eventually relapse. Thus, it is essential to identify possible alternative therapeutic approaches for cancer. We sought to identify alternative and effective therapeutic approaches, by first synthesizing palladium nanoparticles (PdNPs), using a novel biomolecule called saponin. The synthesized PdNPs were characterized by several analytical techniques. They were significantly spherical in shape, with an average size of 5 nm. Recently, PdNPs gained much interest in various therapies of cancer cells. Similarly, histone deacetylase inhibitors are known to play a vital role in anti-proliferative activity, gene expression, cell cycle arrest, differentiation and apoptosis in various cancer cells. Therefore, we selected trichostatin A (TSA) and PdNPs and studied their combined effect on apoptosis in cervical cancer cells. Cells treated with either TSA or PdNPs showed a dose-dependent effect on cell viability. The combinatorial effect, tested with 50 nM TSA and 50 nMPdNPs, had a more dramatic inhibitory effect on cell viability, than either TSA or PdNPs alone. The combination of TSA and PdNPs had a more pronounced effect on cytotoxicity, oxidative stress, mitochondrial membrane potential (MMP), caspase-3/9 activity and expression of pro- and anti-apoptotic genes. Our data show a strong synergistic interaction between TSA and PdNPs in cervical cancer cells. The combinatorial treatment increased the therapeutic potential and demonstrated relevant targeted therapy for cervical cancer. Furthermore, we provide the first evidence for the combinatory effect and cytotoxicity mechanism of TSA and PdNPs in cervical cancer cells.

http://ift.tt/2bqJwjy