168 research outputs found
Liver injury in COVID-19: The hepatic aspect of the respiratory syndrome β what we know so far
Β© 2020. All Rights Reserved. The 2019 novel coronavirus disease (COVID-19) pandemic due to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has posed a serious threat to global public health. Although primarily, the infection causes lung injury, liver enzyme abnormalities have also been reported to occur during the course of the disease. We conducted an extensive literature review using the PubMed database on articles covering a broad range of issues related to COVID-19 and hepatic injury. The present review summarizes available information on the spectrum of liver involvement, the possible mechanisms and risk factors of liver injury due to SARS-CoV-2 infection, and the prognostic significance of the presence of liver injury. Hopefully, this review will enable clinicians, especially the hepatologists, to understand and manage the liver derangements they may encounter in these atients better and provide guidance for further studies on the liver injury of COVID-19
A comparative study of thermal decomposition behaviour of Zn-Cr, Zn-Cr-Al and Zn-Al type layered double hydroxides
Hydrolysis of ZnO in acidic pH provides a facile route for synthesis of layered double hydroxides
(LDH)bearingZn2+withCr3+andAl3+withouthavingcarbonateionintheinter-layer position.The
thermal decomposition of the prepared LDH show that with the increase of Cr3+ content in the
systemthereisanincreaseinthethermalstability ofthecompounds.IncaseofZnβCrLDHthereis
a non-mass loss transition around 420Β°C. Segregation of parent LDH structure to a bivalent oxide
and a spineltakesplacein both ZnβCr and ZnβAl LDH only at temperatures above 550Β°
Control of Ni/Ce1-xMxOy catalyst properties via the selection of dopant M = Gd, La, Mg Part 1. Physicochemical characteristics
To elucidate the role of support composition in autothermal reforming of ethanol (ATR of C2H5OH), a series of Ni catalysts (Ni content 2β15 wt.%) supported on different ceria-based oxides (Ce1-xGdxOy, Ce1-xLaxOy and Ce1-xMgxOy; x = 0.1β0.9) were prepared. The synthetized materials were tested in ATR of ethanol at 200β700 Β°C. It was established that supports themselves show catalytic activity in ATR of C2H5OH and provide 10β15% yield of H2 at 700 Β°C. Upon the increase of Ni content from 2 to 15 wt.% the temperature of 100% ethanol conversion decreases from 700 tΠΎ 300 Β°Π‘, hydrogen yield increases from 25 to 60%, the inhibition of Π‘2-Π‘3 by-products formation, as well as the promotion of decomposition of acetaldehyde occur. The enhancement of catalyst performance in ATR of C2H5OH has been observed in the next series of supports: Ce1-xMgxOy < Ce1-xGdxOy < Ce1-xLaxOy and with a decrease of x to an optimal value that correlates with the improvement of Ni active component reducibility. At 600 Β°C on 10Ni/Ce0.8La0.2O1.9 catalyst the H2 yield of 50% was achieved at C2H5OH conversion of 100%. Stable and high performance of developed catalysts in ATR of C2H5OH indicates the promise of their use in the production of hydrogen
Control of Ni/Ce1-xMxOy Catalyst Properties Via the Selection of Dopant M = Gd, La, Mg. Part 2. Catalytic Activity
To elucidate the role of support composition in autothermal reforming of ethanol (ATR of C2H5OH), a series of Ni catalysts (Ni content 2β15 wt.%) supported on different ceria-based oxides (Ce1-xGdxOy, Ce1-xLaxOy and Ce1-xMgxOy; x = 0.1β0.9) were prepared. The synthetized materials were tested in ATR of ethanol at 200β700 Β°C. It was established that supports themselves show catalytic activity in ATR of C2H5OH and provide 10β15% yield of H2 at 700 Β°C. Upon the increase of Ni content from 2 to 15 wt.% the temperature of 100% ethanol conversion decreases from 700 tΠΎ 300 Β°Π‘, hydrogen yield increases from 25 to 60%, the inhibition of Π‘2-Π‘3 by-products formation, as well as the promotion of decomposition of acetaldehyde occur. The enhancement of catalyst performance in ATR of C2H5OH has been observed in the next series of supports: Ce1-xMgxOy < Ce1-xGdxOy < Ce1-xLaxOy and with a decrease of x to an optimal value that correlates with the improvement of Ni active component reducibility. At 600 Β°C on 10Ni/Ce0.8La0.2O1.9 catalyst the H2 yield of 50% was achieved at C2H5OH conversion of 100%. Stable and high performance of developed catalysts in ATR of C2H5OH indicates the promise of their use in the production of hydrogen
Minimalism in Radiation Synthesis of Biomedical Functional Nanogels
A scalable, single-step, synthetic approach for the manufacture of
biocompatible, functionalized micro- and nanogels is presented. In particular,
poly(N-vinyl pyrrolidone)-grafted-(aminopropyl)methacrylamide microgels and
nanogels were generated through e-beam irradiation of PVP aqueous solutions in
the presence of a primary amino-group-carrying monomer. Particles with
different hydrodynamic diameters and surface charge densities were obtained at
the variance of the irradiation conditions. Chemical structure was investigated by
different spectroscopic techniques. Fluorescent variants were generated through
fluorescein isothiocyanate attachment to the primary amino groups grafted to
PVP, to both quantify the available functional groups for bioconjugation and
follow nanogels localization in cell cultures. Finally, a model protein, bovine
serum albumin, was conjugated to the nanogels to demonstrate the attachment
of biologically relevant molecules for targeting purposes in drug delivery. The
described approach provides a novel strategy to fabricate biohybrid nanogels
with a very promising potential in nanomedicine
A novel a-L-Arabinofuranosidase of Family 43 Glycoside Hydrolase (Ct43Araf ) from Clostridium thermocellum
Articles in International JournalsThe study describes a comparative analysis of biochemical, structural and functional properties of two recombinant
derivatives from Clostridium thermocellum ATCC 27405 belonging to family 43 glycoside hydrolase. The family 43 glycoside
hydrolase encoding a-L-arabinofuranosidase (Ct43Araf) displayed an N-terminal catalytic module CtGH43 (903 bp) followed
by two carbohydrate binding modules CtCBM6A (405 bp) and CtCBM6B (402 bp) towards the C-terminal. Ct43Araf and its
truncated derivative CtGH43 were cloned in pET-vectors, expressed in Escherichia coli and functionally characterized. The
recombinant proteins displayed molecular sizes of 63 kDa (Ct43Araf) and 34 kDa (CtGH43) on SDS-PAGE analysis. Ct43Araf
and CtGH43 showed optimal enzyme activities at pH 5.7 and 5.4 and the optimal temperature for both was 50uC. Ct43Araf
and CtGH43 showed maximum activity with rye arabinoxylan 4.7 Umg21 and 5.0 Umg21, respectively, which increased by
more than 2-fold in presence of Ca2+ and Mg2+ salts. This indicated that the presence of CBMs (CtCBM6A and CtCBM6B) did
not have any effect on the enzyme activity. The thin layer chromatography and high pressure anion exchange
chromatography analysis of Ct43Araf hydrolysed arabinoxylans (rye and wheat) and oat spelt xylan confirmed the release of
L-arabinose. This is the first report of a-L-arabinofuranosidase from C. thermocellum having the capacity to degrade both pnitrophenol-
a-L-arabinofuranoside and p-nitrophenol-a-L-arabinopyranoside. The protein melting curves of Ct43Araf and
CtGH43 demonstrated that CtGH43 and CBMs melt independently. The presence of Ca2+ ions imparted thermal stability to
both the enzymes. The circular dichroism analysis of CtGH43 showed 48% b-sheets, 49% random coils but only 3% a-helices
Advances and Prospect of Nanotechnology in Stem Cells
In recent years, stem cell nanotechnology has emerged as a new exciting field. Theoretical and experimental studies of interaction between nanomaterials or nanostructures and stem cells have made great advances. The importance of nanomaterials, nanostructures, and nanotechnology to the fundamental developments in stem cells-based therapies for injuries and degenerative diseases has been recognized. In particular, the effects of structure and properties of nanomaterials on the proliferation and differentiation of stem cells have become a new interdisciplinary frontier in regeneration medicine and material science. Here we review some of the main advances in this field over the past few years, explore the application prospects, and discuss the issues, approaches and challenges, with the aim of improving application of nanotechnology in the stem cells research and development
Nonviral Approaches for Neuronal Delivery of Nucleic Acids
The delivery of therapeutic nucleic acids to neurons has the potential to treat neurological disease and spinal cord injury. While select viral vectors have shown promise as gene carriers to neurons, their potential as therapeutic agents is limited by their toxicity and immunogenicity, their broad tropism, and the cost of large-scale formulation. Nonviral vectors are an attractive alternative in that they offer improved safety profiles compared to viruses, are less expensive to produce, and can be targeted to specific neuronal subpopulations. However, most nonviral vectors suffer from significantly lower transfection efficiencies than neurotropic viruses, severely limiting their utility in neuron-targeted delivery applications. To realize the potential of nonviral delivery technology in neurons, vectors must be designed to overcome a series of extra- and intracellular barriers. In this article, we describe the challenges preventing successful nonviral delivery of nucleic acids to neurons and review strategies aimed at overcoming these challenges
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