Two-dimensional (2D) materials have attracted much attention due to their unique properties and great potential in various applications. Controllable synthesis of 2D materials with high quality and ...high efficiency is essential for their large scale applications. Chemical vapor deposition (CVD) has been one of the most important and reliable techniques for the synthesis of 2D materials. In this perspective, the recent advances in the CVD growth of three typical types of two-dimensional materials, graphene, boron nitride and transition metal dichalcogenides (TMDs), are briefly introduced. Large area preparation, single crystal growth and some mechanistic insight are discussed with details. Finally we give a brief comment on the challenges of CVD growth of 2D materials.
The synthesis of high quality two-dimensional materials such as graphene, BN, and transition metal dichalcogenides by CVD provides a new opportunity for large scale applications.
Full text
Available for:
IJS, KILJ, NUK, UL, UM, UPUK
This paper presents the large-scale synthesis of SnO2 nanotube arrays on titanium substrate via ZnO nanowire arrays as sacrificial templates. The SnO2 nanotube arrays on titanium substrate feature ...the large surface area, good electronic conductivity, and adhesion with the current collector, leading to the enhanced performance in lithium-ion batteries.
Full text
Available for:
IJS, KILJ, NUK, PNG, UL, UM
A simple microemulsion-based method has been developed to synthesize ZnCo2(C2O4)3 nanowires that can be transformed to porous ZnCo2O4 nanowires under annealing conditions. The morphology of porous ...ZnCo2O4 nanowires can be tuned by the initial ZnCo2(C2O4)3 nanowires and the annealing temperatures. The as-synthesized porous ZnCo2O4 nanowires have been applied as anode materials of Li-ion batteries, which show superior capacity and cycling performance. The porous one-dimensional (1D) nanostructures and large surface area are responsible for the superior performance. Moreover, it is indicated that porous ZnCo2O4 nanowires synthesized at low annealing temperature (500 °C) show larger capacity and better cycling performance than that prepared at high annealing temperature (700 °C), because of their higher porosity and larger surface area.
Full text
Available for:
IJS, KILJ, NUK, PNG, UL, UM
RORγt and RORα are transcription factors of the RAR-related orphan nuclear receptor (ROR) family. They are expressed in Th17 cells and have been suggested to play a role in Th17 differentiation. ...Although RORγt signature genes have been characterized in mouse Th17 cells, detailed information on its transcriptional control in human Th17 cells is limited and even less is known about RORα signature genes which have not been reported in either human or mouse T cells. In this study, global gene expression of human CD4 T cells activated under Th17 skewing conditions was profiled by RNA sequencing. RORγt and RORα signature genes were identified in these Th17 cells treated with specific siRNAs to knock down RORγt or RORα expression. We have generated selective small molecule RORγt modulators and they were also utilized as pharmacological tools in RORγt signature gene identification. Our results showed that RORγt controlled the expression of a very selective number of genes in Th17 cells and most of them were regulated by RORα as well albeit a weaker influence. Key Th17 genes including IL-17A, IL-17F, IL-23R, CCL20 and CCR6 were shown to be regulated by both RORγt and RORα. Our results demonstrated an overlapping role of RORγt and RORα in human Th17 cell differentiation through regulation of a defined common set of Th17 genes. RORγt as a drug target for treatment of Th17 mediated autoimmune diseases such as psoriasis has been demonstrated recently in clinical trials. Our results suggest that RORα could be involved in same disease mechanisms and gene signatures identified in this report could be valuable biomarkers for tracking the pharmacodynamic effects of compounds that modulate RORγt or RORα activities in patients.
Full text
Available for:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
EBI2 (also called GPR183) is an orphan G-protein-coupled receptor that is highly expressed in spleen and upregulated upon Epstein-Barr-virus infection. Recent studies indicated that this receptor ...controls follicular B-cell migration and T-cell-dependent antibody production. Oxysterols elicit profound effects on immune and inflammatory responses as well as on cholesterol metabolism. The biological effects of oxysterols have largely been credited to the activation of nuclear hormone receptors. Here we isolate oxysterols from porcine spleen extracts and show that they are endogenous ligands for EBI2. The most potent ligand and activator is 7α,25-dihydroxycholesterol (OHC), with a dissociation constant of 450 pM for EBI2. In vitro, 7α,25-OHC stimulated the migration of EBI2-expressing mouse B and T cells with half-maximum effective concentration values around 500 pM, but had no effect on EBI2-deficient cells. In vivo, EBI2-deficient B cells or normal B cells desensitized by 7α,25-OHC pre-treatment showed reduced homing to follicular areas of the spleen. Blocking the synthesis of 7α,25-OHC in vivo with clotrimazole, a CYP7B1 inhibitor, reduced the content of 7α,25-OHC in the mouse spleen and promoted the migration of adoptively transferred pre-activated B cells to the T/B boundary (the boundary between the T-zone and B-zone in the spleen follicle), mimicking the phenotype of pre-activated B cells from EBI2-deficient mice. Our results show an unexpected causal link between EBI2, an orphan G-protein-coupled receptor controlling B-cell migration, and the known immunological effects of certain oxysterols, thus uncovering a previously unknown role for this class of molecules.
Full text
Available for:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Lactic acid is a well known metabolic by-product of intense exercise, particularly under anaerobic conditions. Lactate is also a key source of energy and an important metabolic substrate, and it has ...also been hypothesized to be a signaling molecule directing metabolic activity. Here we show that GPR81, an orphan G-protein-coupled receptor highly expressed in fat, is in fact a sensor for lactate. Lactate activates GPR81 in its physiological concentration range of 1–20 mm and suppresses lipolysis in mouse, rat, and human adipocytes as well as in differentiated 3T3-L1 cells. Adipocytes from GPR81-deficient mice lack an antilipolytic response to lactate but are responsive to other antilipolytic agents. Lactate specifically induces internalization of GPR81 after receptor activation. Site-directed mutagenesis of GPR81 coupled with homology modeling demonstrates that classically conserved key residues in the transmembrane binding domains are responsible for interacting with lactate. Our results indicate that lactate suppresses lipolysis in adipose tissue through a direct activation of GPR81. GPR81 may thus be an attractive target for the treatment of dyslipidemia and other metabolic disorders.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
We demonstrate the synthesis of order-aligned Mn3O4 nanostructures by electrochemically depositing Mn3O4 on a pre-fabricated Cu nanowire array current collector. When used as an electrode for ...lithium-ion batteries, it exhibits a capacity up to 637 and 494 mA h g−1 after 100 cycles at a current rate of 10 C and 20 C (10 C = 9.4 A g−1), respectively. The excellent cycling performance and superior rate capability can be attributed to the good electrical contact, fast electron transport and good strain accommodation of the order-aligned nanostructured electrodes. The relationship between the thickness of the Mn3O4 film and its electrochemical performance has also been investigated.
► Mn3O4 layer was deposited on Cu nanowire arrays via electrochemical method. ► The 3D electrodes show improved performance as anode for Li-ion battery. ► Improved performance was attributed to the advantages of the electrodes' structure.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Cu–Sn core–shell three-dimensional electrodes have been successfully synthesized by directly depositing metallic Sn on the surface of presynthesized Cu nanowire arrays. When used as an anode for ...lithium-ion batteries, the Cu–Sn three-dimensional electrode exhibits a high reversible capacity, a high initial Coulombic efficiency, a good rate capability, and an improved capacity retention. The effect of the thickness of the Sn layer on the Li-ion battery performance has also been investigated. The efficient buffering of the volume change, fast transport of electrons, and good contact to the current collector of the array structure may be responsible for the good cycling performance.
Full text
Available for:
IJS, KILJ, NUK, PNG, UL, UM
► SiGe layer was deposited on the Cu nanowire arrays via a co-sputtering method. ► The Cu–SiGe 3D electrodes show improved performance as anode for Li-ion battery. ► Improved performance was ...attributed to the advantages of the electrodes’ structure.
We demonstrate the synthesis of new Cu–Si1−xGex core–shell nanowire array electrodes by directly depositing Si1−xGex layer on the surface of pre-synthesized Cu nanowire arrays via co-sputtering method. When used as anodes of lithium-ion batteries, the Cu–Si1−xGex (x=0.4) nanowire array electrodes show excellent electrochemical performance in terms of cycle stability and rate capability, which is much better than that of planar electrodes. The improved performance can be attributed to the good strain accommodation, fast electron transport and good electrical contact of the nanowire array electrodes. The effect of Ge content and the thickness of alloy film on the electrochemical performance of the three-dimensional electrodes have also been investigated.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Niacin raises high-density lipoprotein and lowers low-density lipoprotein through the activation of the β-hydroxybutyrate receptor hydroxycarboxylic acid 2 (HCA2) (aka GPR109a) but with an unwanted ...side effect of cutaneous flushing caused by vascular dilation because of the stimulation of HCA2 receptors in Langerhans cells in skin. HCA1 (aka GPR81), predominantly expressed in adipocytes, was recently identified as a receptor for lactate. Activation of HCA1 in adipocytes by lactate results in the inhibition of lipolysis, suggesting that agonists for HCA1 may be useful for the treatment of dyslipidemia. Lactate is a metabolite of glucose, suggesting that HCA1 may also be involved in the regulation of glucose metabolism. The low potency of lactate to activate HCA1, coupled with its fast turnover rate in vivo, render it an inadequate tool for studying the biological role of lactate/HCA1 in vivo. In this article, we demonstrate the identification of 3-hydroxybenzoic acid (3-HBA) as an agonist for both HCA2 and HCA1, whereas 3,5-dihydroxybenzoic acid (3,5-DHBA) is a specific agonist for only HCA1 (EC(50) ∼150 μM). 3,5-DHBA inhibits lipolysis in wild-type mouse adipocytes but not in HCA1-deficient adipocytes. Therefore, 3,5-DHBA is a useful tool for the in vivo study of HCA1 function and offers a base for further HCA1 agonist design. Because 3-HBA and 3,5-DHBA are polyphenolic acids found in many natural products, such as fruits, berries, and coffee, it is intriguing to speculate that other heretofore undiscovered natural substances may have therapeutic benefits.
PDF
