Increasing fresh water demand for drinking and agriculture is one of the grand challenges of our age. Graphene oxide (GO) membranes have shown a great potential for desalination and water ...purification. However, it is challenging to further improve the water permeability without sacrificing the separation efficiency, and the GO membranes are easily delaminated in aqueous solutions within few hours. Here, we report a class of reduced GO membranes with enlarged interlayer distance fabricated by using theanine amino acid and tannic acid as reducing agent and cross-linker. Such membranes show water permeance over 10,000 L m
h
bar
, which is 10-1000 times higher than those of previously reported GO-based membranes and commercial membranes, and good separation efficiency, e.g., rhodamine B and methylene blue rejection of ~100%. Moreover, they show no damage or delamination in water, acid, and basic solutions even after months.
Hyperinsulinaemic hypoglycaemia is a cause of persistent hypoglycaemia in the neonatal and infancy periods. Prompt recognition and management of patients with hyperinsulinaemic hypoglycaemia are ...essential, if brain damage and long-term neurological sequelae are to be avoided. Hyperinsulinaemic hypoglycaemia can be transient, prolonged, or persistent (congenital). Advances in the fields of molecular biology, genetics, and pancreatic beta-cell physiology are beginning to provide novel insights into the mechanisms causing congenital forms of hyperinsulinism. So far mutations in six different genes have been described that lead to unregulated insulin secretion. The histological differentiation of focal and diffuse congenital hyperinsulinism has radically changed the surgical approach to this disease. Until recently, highly invasive investigations were performed to localize the focal lesion, but recent experience with (18)F-L-dopa positron emission tomography scanning suggests that this technique is highly sensitive for differentiating diffuse from focal disease as well as for accurately locating the focal lesion. Despite recent advances, the genetic basis of congenital hyperinsulinism is still unknown in about 50% of the patients, and the management of medically unresponsive diffuse disease remains a real challenge.
A pot study was conducted to explore the effectiveness of zinc oxide nanoparticles (ZnO NPs) foliar exposure on growth and development of wheat, zinc (Zn) and cadmium (Cd) uptake in Cd-contaminated ...soil under various moisture conditions. Four different levels (0, 25, 50, 100 mg/L) of these NPs were foliar-applied at different time periods during the growth of wheat. Two soil moisture regimes (70% and 35% of water holding capacity) were maintained from 6 weeks of germination till plant harvesting. The results revealed that the growth of wheat increased with ZnO NPs treatments. The best results were found in 100 mg/L ZnO NPs under normal moisture level. The lowest Cd and highest Zn concentrations were also examined when 100 mg/L NPs were applied without water deficit stress. In grain, Cd concentrations decreased by 26%, 81% and 87% in normal moisture while in water deficit conditions, the Cd concentrations decreased by 35%, 66% and 81% compared to control treatment when ZnO NPs were used at 25, 50 and 100 mg/L. The foliar exposure of ZnO NPs boosted up the leaf chlorophyll contents and also decreased the oxidative stress and enhanced the leaf superoxide dismutase and peroxidase activities than the control. It can be suggested that foliar use of ZnO NPs might be an efficient way for increasing wheat growth and yield with maximum Zn and minimum Cd contents under drought stress while decreasing the chances of NPs movement to other environmental compartment which may be possible in soil applied NPs.
•Cadmium (Cd) and water stress negatively affected shoot, roots and grain yield of wheat.•Foliar application of zinc oxide nanoparticles (ZnO NPs) improved the growth under stress.•Foliar ZnO NPs improved chlorophyll contents and minimized oxidative stress in shoots.•Foliar ZnO NPs increased Zn and decreased Cd contents in wheat grains under Cd and water deficient stress.
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Tailoring the pore structure and surface chemistry of graphene-based laminates is essentially important for their applications as separation membranes. Usually, pure graphene oxide ...(GO) and completely reduced GO (rGO) membranes suffer from low water permeance because of the lack of pristine graphitic sp2 domains and very small interlayer spacing, respectively. In this work, we studied the influence of reduction degree on the structure and separation performance of rGO membranes. It was found that weak reduction retains the good dispersion and hydrophilicity of GO nanosheets. More importantly, it increases the number of pristine graphitic sp2 domains in rGO nanosheets while keeping the large interlayer spacing of the GO membranes in most regions at the same time. The resultant membranes show a high water permeance of 56.3 L m−2 h−1 bar−1, which is about 4 times and over 104 times larger than those of the GO and completely reduced rGO membranes, respectively, and high rejection over 95% for various dyes. Furthermore, they show better structure stability and more superior separation performance than GO membranes in acid and alkali environments.
In this study, two-dimensional graphene oxide-based novel membranes were fabricated by modifying the surface of graphene oxide nanosheets with six-armed poly(ethylene glycol) (PEG) at room ...conditions. The as-modified PEGylated graphene oxide (PGO) membranes with unique layered structures and large interlayer spacing (∼1.12 nm) were utilized for organic solvent nanofiltration applications. The as-prepared 350 nm-thick PGO membrane offers a superior separation (>99%) against evans blue, methylene blue and rhodamine B dyes along with high methanol permeance ∼ 155 ± 10 L m
−2
h
−1
, which is 10-100 times high compared to pristine GO membranes. Additionally, these membranes are stable for up to 20 days in organic solvent. Hence the results suggested that the as-synthesized PGO membranes with superior separation efficiency for dye molecules in organic solvent can be used in future for organic solvent nanofiltration application.
In this study, two-dimensional graphene oxide-based novel membranes were fabricated by modifying the surface of graphene oxide nanosheets with six-armed poly(ethylene glycol) (PEG) at room conditions and used for organic solvent nanofiltration applications.
Graphene oxide (GO) lamellar membranes have attracted a lot of attention as a possible solution for water purification applications. In this work, asparagine amino acid-modified GO-based membranes ...(As@GO) are prepared with different thicknesses. The as-prepared As@GO-based membranes are used for the separation of organic dyes and heavy metal ions. The 300 nm-thick As@GO multilayer membrane shows high rejection,
i.e.
, 99.8% and 99.9% of methylene blue (MLB) and rhodamine B (RB) dyes, respectively, along with an exceptional water permeability of ∼1740 ± 10 L m
−2
h
−1
bar
−1
. Furthermore, the As@GO membrane also demonstrates excellent rejection of up to 95.6% and 96.7% for cadmium (Cd
2+
) and lead (Pb
2+
) ions, respectively. These membranes are also highly stable in water for up to 34 days and do not swell. These results suggest the valuable experimental basis for the design and development of stable GO membranes (GOMs) with high permeability and superior separation selectivity for applications in the separation fields of valuable metal ion extraction from seawater and other wastewater purification,
etc.
Asparagine-modified GO membranes are prepared to efficiently reject rhodamine B dye up to 99.9%, along with a water permeability of ∼1740 ± 10 L m
−2
h
−1
bar
−1
. Further, such membranes are stable in water up to 34 days.
Congenital hyperinsulinism (CHI) is a heterogenous and complex disorder in which the unregulated insulin secretion from pancreatic beta-cells leads to hyperinsulinaemic hypoglycaemia. The severity of ...hypoglycaemia varies depending on the underlying molecular mechanism and genetic defects. The genetic and molecular causes of CHI include defects in pivotal pathways regulating the secretion of insulin from the beta-cell. Broadly these genetic defects leading to unregulated insulin secretion can be grouped into four main categories. The first group consists of defects in the pancreatic K
channel genes (
and
). The second and third categories of conditions are enzymatic defects (such as GDH, GCK, HADH) and defects in transcription factors (for example HNF1α, HNF4α) leading to changes in nutrient flux into metabolic pathways which converge on insulin secretion. Lastly, a large number of genetic syndromes are now linked to hyperinsulinaemic hypoglycaemia. As the molecular and genetic basis of CHI has expanded over the last few years, this review aims to provide an up-to-date knowledge on the genetic causes of CHI.
In this work, we prepare samarium-doped ceria (SDC) nanocomposite electrolytes by the co-precipitation method with different ZnO:SDC weight ratios for solid oxide fuel cell application. The ...physicochemical characterization of the nanocomposite electrolytes is carried out by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC) techniques. Electrochemical impedance spectroscopy is performed to measure the electrical properties of the electrolytes, and the results show that the optimum composition of ZnO (
x
= 0.2) nanocomposite demonstrates a better ionic conductivity ~ 0.1–0.7 S/cm at 350–700 °C. The fuel cell performance of the ZnO/SDC nanocomposite electrolytes is measured with hydrogen as the fuel. The as-synthesized nanocomposite material with ZnO (
x
= 0.2) also exhibits a power density of 804 mW/cm
2
along with a maximum open-circuit voltage (OCV) of 1.10 V at 700 °C.
This paper reviews the state of phosphor thermometry, focusing on developments in the past 15 years. The fundamental principles and theory are presented, and the various spectral and temporal modes, ...including the lifetime decay, rise time and intensity ratio, are discussed. The entire phosphor measurement system, including relative advantages to conventional methods, choice of phosphors, bonding techniques, excitation sources and emission detection, is reviewed. Special attention is given to issues that may arise at high temperatures. A number of recent developments and applications are surveyed, with examples including: measurements in engines, hypersonic wind tunnel experiments, pyrolysis studies and droplet/spray/gas temperature determination. They show the technique is flexible and successful in measuring temperatures where conventional methods may prove to be unsuitable.
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