Attempts to Change the Globally Accepted Term, CKDu, to KDUCAL, NUCAL, or CINAC Are Inappropriate

We are concerned about the suggestion by Drs Subramanian and Javaid in AJKD1 and elsewhere2 to replace the term chronic kidney disease (CKD) of unknown origin (CKDu), which affects Sri Lanka and several tropical countries, with "kidney disease of unknown cause in agricultural laborers" (KDUCAL) and to replace Mesoamerican nephropathy (MeN) with "nephropathy of unknown cause in agricultural laborers" (NUCAL). These terms, as well as chronic interstitial nephritis in agricultural communities (CINAC)3 and "agrochemical nephropathy,"4 imply that CKDu affects only agricultural laborers exposed to agrochemicals.

http://ift.tt/2FClgso

In Reply to ‘Attempts to Change the Globally Accepted Term, CKDu, to KDUCAL, NUCAL, or CINAC Are Inappropriate’

We acknowledge some of the points raised by Drs Wimalawansa and Ileperuma1 and thank them for their interest in our article. However, we respectfully maintain our position that these types of kidney diseases need to be named with more clarity than just a term that indicates their geographical occurrence, such as "MesoAmerican nephropathy" or "Udhanam nephropathy," or a term that does not reflect strong associations, such as "CKD-U."

http://ift.tt/2Hgr0VT

Flower Kidney: The Gift of Giving

Chronic kidney disease is a diagnosis that our patients do not want to hear. However, as nephrologists we are often the bearer of these dreaded words. What is even more challenging for us is to tell patients that they will need renal replacement therapy, be it hemodialysis or peritoneal dialysis. These are life-changing words that will impact the quality of our patients' lives. They have to cope with and accept the changes created by the need for lifelong medical care.

http://ift.tt/2FCCVR2

Programming Cells for Dynamic Assembly of Inorganic Nano-Objects with Spatiotemporal Control

Abstract

Programming living cells to organize inorganic nano-objects (NOs) in a spatiotemporally precise fashion would advance new techniques for creating ordered ensembles of NOs and new bio–abiotic hybrid materials with emerging functionalities. Bacterial cells often grow in cellular communities called biofilms. Here, a strategy is reported for programming dynamic biofilm formation for the synchronized assembly of discrete NOs or hetero-nanostructures on diverse interfaces in a dynamic, scalable, and hierarchical fashion. By engineering Escherichia coli to sense blue light and respond by producing biofilm curli fibers, biofilm formation is spatially controlled and the patterned NOs' assembly is simultaneously achieved. Diverse and complex fluorescent quantum dot patterns with a minimum patterning resolution of 100 µm are demonstrated. By temporally controlling the sequential addition of NOs into the culture, multilayered heterostructured thin films are fabricated through autonomous layer-by-layer assembly. It is demonstrated that biologically dynamic self-assembly can be used to advance a new repertoire of nanotechnologies and materials with increasing complexity that would be otherwise challenging to produce.

A strategy for programming dynamic biofilm formation is reported for the synchronized assembly of inorganic nano-objects (NOs) in a dynamic, scalable, and hierarchical fashion. Diverse and complex fluorescent quantum dot patterns with a minimum resolution of 100 µm are achieved through programed light regulation. Multilayered heterostructured films through layer-by-layer assembly are demonstrated by temporally controlling the sequential addition of NOs.

http://ift.tt/2HhBEf0

2D Ruddlesden–Popper Perovskites Microring Laser Array

Abstract

3D organic–inorganic hybrid perovskites have featured high gain coefficients through the electron–hole plasma stimulated emission mechanism, while their 2D counterparts of Ruddlesden–Popper perovskites (RPPs) exhibit strongly bound electron–hole pairs (excitons) at room temperature. High-performance solar cells and light-emitting diodes (LEDs) are reported based on 2D RPPs, whereas light-amplification devices remain largely unexplored. Here, it is demonstrated that ultrafast energy transfer along cascade quantum well (QW) structures in 2D RPPs concentrates photogenerated carriers on the lowest-bandgap QW state, at which population inversion can be readily established enabling room-temperature amplified spontaneous emission and lasing. Gain coefficients measured for 2D RPP thin-films (≈100 nm in thickness) are found about at least four times larger than those for their 3D counterparts. High-density large-area microring arrays of 2D RPPs are fabricated as whispering-gallery-mode lasers, which exhibit high quality factor (Q ≈ 2600), identical optical modes, and similarly low lasing thresholds, allowing them to be ignited simultaneously as a laser array. The findings reveal that 2D RPPs are excellent solution-processed gain materials potentially for achieving electrically driven lasers and ideally for on-chip integration of nanophotonics.

Room-temperature 2D Ruddlesden–Popper perovskite (RPP) amplified spontaneous emission and lasing are achieved by ultrafast energy transfer along the cascade quantum well to concentrate on the lowest-bandgap quantum well for population inversion. High-density large-area microring arrays of 2D-RPPs are fabricated as whispering-gallery-mode lasers with high quality factor, identical optical modes, and similarly low lasing threshold.

http://ift.tt/2FwTfmd

From Nanostructural Evolution to Dynamic Interplay of Constituents: Perspectives for Perovskite Solar Cells

Abstract

Moving away from the high-performance achievements in organometal halide perovskite (OHP)-based optoelectronic and photovoltaic devices, intriguing features have been reported in that photocarriers and mobile ionic species within OHPs interact with light, electric fields, or a combination of both, which induces both spatial and temporal changes of optoelectronic properties in OHPs. Since it is revealed that the transport of photocarriers and the migration of ionic species are affected not only by each other but also by the inhomogeneous character, which is a consequence of the route selected to deposit OHPs, understanding the nanostructural evolution during OHP deposition, in terms of the resultant structural defects, electronic traps, and nanoscopic charge behaviors, will be valuable. Investigation of the film-growth mechanisms and strategies adopted to realize OHP films with less-defective large grains is of central importance, considering that single-crystalline OHPs have exhibited the most beneficial properties, including carrier lifetimes. Critical factors governing the behavior of photocarriers, mobile ionic species, and nanoscale optoelectronic properties resulting from either or all of them are further summarized, which may potentially limit or broaden the optoelectronic and photovoltaic applications of OHPs. Through inspection of the recent advances, a comprehensive picture and future perspective of OHPs are provided.

With giant steps regarding organometal halide perovskite (OHP)-based optoelectronic and photovoltaic devices having been made, OHPs are being driven toward applications beyond photovoltaics. Recent progress regarding the various characteristics of OHPs and their impact on photovoltaic devices are reviewed, from microstructural evolution coupled with nanostructural/electronic disorder to photoinduced charge-carrier dynamics; the implications for potential applications are also outlined.

http://ift.tt/2Hh6pRF

Ultrathin Hierarchical Porous Carbon Nanosheets for High-Performance Supercapacitors and Redox Electrolyte Energy Storage

Abstract

The design of advanced high-energy-density supercapacitors requires the design of unique materials that combine hierarchical nanoporous structures with high surface area to facilitate ion transport and excellent electrolyte permeability. Here, shape-controlled 2D nanoporous carbon sheets (NPSs) with graphitic wall structure through the pyrolysis of metal–organic frameworks (MOFs) are developed. As a proof-of-concept application, the obtained NPSs are used as the electrode material for a supercapacitor. The carbon-sheet-based symmetric cell shows an ultrahigh Brunauer–Emmett–Teller (BET)-area-normalized capacitance of 21.4 µF cm⁻² (233 F g⁻¹), exceeding other carbon-based supercapacitors. The addition of potassium iodide as redox-active species in a sulfuric acid (supporting electrolyte) leads to the ground-breaking enhancement in the energy density up to 90 Wh kg⁻¹, which is higher than commercial aqueous rechargeable batteries, maintaining its superior power density. Thus, the new material provides a double profits strategy such as battery-level energy and capacitor-level power density.

Shape-controlled 2D hierarchical nanoporous carbon sheets derived from metal–organic framework achieving excellent surface-area-normalized capacitance are prepared. Further, the effect of the addition of KI redox-active species in the aqueous electrolyte to enhance the performance is explored.

http://ift.tt/2FBz72j