Synthesis of full concentration gradient cathode studied by high energy X-ray diffraction

Li, Yan,Xu, Rui,Ren, Yang,Lu, Jun,Wu, Huiming,Wang, Lifen,Miller, Dean J.,Sun, Yang-Kook,Amine, Khalil,Chen, Zonghai Elsevier 2016 Nano energy Vol.19 No.-

<P><B>Abstract</B></P> <P>Nickel-rich metal oxides have been widely pursued as promising cathode materials for high energy-density lithium-ion batteries. Nickel-rich lithium transition metal oxides can deliver a high specific capacity during cycling, but can react with non-aqueous electrolytes. In this work, we have employed a full concentration gradient (FCG) design to provide a nickel-rich core to deliver high capacity and a manganese-rich outer layer to provide enhanced stability and cycle life. <I>In situ</I> high-energy X-ray diffraction was utilized to study the structural evolution of oxides during the solid-state synthesis of FCG lithium transition metal oxide with a nominal composition of LiNi<SUB>0.6</SUB>Mn<SUB>0.2</SUB>Co<SUB>0.2</SUB>O<SUB>2</SUB>. We found that both the pre-heating step and the sintering temperature were critical in controlling phase separation of the transition metal oxides and minimizing the content of Li<SUB>2</SUB>CO<SUB>3</SUB> and NiO, both of which deteriorate the electrochemical performance of the final material. The insights revealed in this work can also be utilized for the design of other nickel-rich high energy-density cathode materials.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Solid-state synthesis of FCG cathode is investigated by <I>in situ</I> XRD. </LI> <LI> Covariance analysis and Rietveld refinement are used to analyze the HEXRD data. </LI> <LI> Synthetic optimization of FCG cathode with excellent electrochemical performance. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>Benefit from the covariance analysis and Rietveld refinement of <I>in situ</I> HEXRD data during the solid state synthesis, we can optimized the solid state synthesis conditions in a short time. And the full concentration gradient cathode composites (nickel-rich core and manganese-rich outer layer) with excellent electrochemical performance are obtained.</P> <P>[DISPLAY OMISSION]</P>

A Mild Strategy to Strengthen Three Dimensional Graphene Aerogel for Supporting Sulfur as a Free‐standing Cathode in Lithium–Sulfur Batteries

Yinglin Yan,Haichao Qin,Yiqi Wei,Rong Yang,Yunhua Xu,Liping Chen,Qiaole Li,Mangmang Shi 대한화학회 2018 Bulletin of the Korean Chemical Society Vol.39 No.5

Recently, three dimensional graphene aerogel (3DGA) supported sulfur microparticles was used as a cathode material for lithium?sulfur batteries, which was considered as one of the most promising next generation rechargeable batteries due to its ultra?high theoretical specific capacity (1675 mAh/g). However, the mechanical strength of 3DGA remains an issue for further application. Herein, a strengthened 3DGA (S3DGA) was achieved by soaking in a low concentration ammonia solution at a relative low temperature. Then the S3DGA loaded sulfur (S3DGA?S) was cut into a round piece and directly used as a cathode without additional binders or conductive additives in Li?S batteries. The mechanical strength, microstructure, and electrochemical properties were investigated by compare with a 3DGA prepared without strengthen. The S3DGA?S presented good mechanical strength, excellent capacity retention, and lower electrochemical impedance.

Intragranular and Intergranular Crack Propagation in Nanocrystalline Ni Under Single-Cycle Mode I Loading

Yan Feng,Jie Li,Xinhua Yang 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.7

As the first step to study the fatigue crack propagation, the molecular simulations were performed to investigate theopening, propagation and closure behaviors of intragranular and intergranular cracks in nanocrystalline Ni under single-cyclemode I loading. The atomic crack angle was proposed to characterize the crack-tip blunting and sharpening quantitatively. There are obvious different mechanisms between intragranular and intergranular crack propagation. Intragranular crack propagationcould be induced by stacking faults and can change its direction very easily, but the intergranular crack perpendicularto the loading direction would propagate along the grain boundary and encounter strong resistance at the triple junction. New cracks could form in the grain boundaries ahead of the original crack. Different from the traditional understanding forintragranular and intergranular cracks, however, the dislocation density increases even in the unloading process and the cracktip is possibly sharpened temporarily during loading.

Nodule Rich Protein 2 modulates nodule number in Medicago truncatula

Junhui Yan,Xinwei Yang,Yawen Wang,Liangliang Yu,Li Luo 한국식물생명공학회 2021 Plant biotechnology reports Vol.15 No.1

Symbiotic nitrogen fxation is beneft to sustainable agriculture and global nitrogen cycle. Many small peptides were identifed as regulators involving in the interaction between rhizobia and legume. Here we reported Nodule Rich Protein 2 (MtNRP2) encoding a small peptide in Medicago truncatula, belonged to a group of nodule rich protein restricted in legume species. MtNRP2 expressed highly in root nodule and its promoter was active during the initiation and development of root nodule and lateral root. To investigate the function of MtNRP2 in nodulation, we generated MtNRP2-overexpression and MtNRP2- knockdown transgenic Medicago. MtNRP2-overexpression transgenic lines performed normal nodulation phenotype compared with vector control. However, in the MtNRP2-RNAi transgenic plants, the decrease of MtNRP2 expression lead to the increase of infection threads number (7 day post inoculation) and nodules number (3 week post inoculation); meanwhile, the expression of MtRGF3 and MtPUB1 was inhibited. These results suggested that MtNRP2 negatively regulated nodulation in Medicago truncatula.

CdSe@ZnS/ZnS quantum dots loaded in polymeric micelles as a pH-triggerable targeting fluorescence imaging probe for detecting cerebral ischemic area

Yang, Hong Yu,Fu, Yan,Jang, Moon-Sun,Li, Yi,Yin, Wen Ping,Ahn, Tae Kyu,Lee, Jung Hee,Chae, Heeyeop,Lee, Doo Sung Elsevier 2017 Colloids and surfaces. B, Biointerfaces Vol.155 No.-

<P><B>Abstract</B></P> <P>High photoluminescence (PL) quantum yield (QY), photostability CdSe@ZnS/ZnS core/multishell quantum dots (CM-QDs) were first applied for bioimaging. The solubility, stability and biocompatible of the fluorescence imaging probes were constructed by self-assembly of CM-QDs and pH-responsive methoxy poly(ethylene glycol)-poly(β-amino ester/amidoamine)-dodecylamine (mPEG-PAEA-DDA) multiblock copolymers. The resulting CM-QDs-loaded mPEG-PAEA-DDA micelles (CM-QDs-PEG-PAEA-DDA) exhibited lower cell cytotoxicity and higher fluorescence intensity than the core/shell CdSe@ZnS QDs-encapsulated mPEG-PAEA-DDA micelles (CS-QDs-PEG-PAEA-DDA). Moreover, the in vivo fluorescence imaging ability confirmed that the CM-QDs-PEG-PAEA-DDA can be employed as a pH-triggerable targeting imaging probe for detection of a rat bearing cerebral ischemia disease. Therefore, we believed that the CM-QDs-PEG-PAEA-DDA may be the next generation of fluorescence imaging probes for targeted diagnosis acidic pathological areas, using pH as a stimulus.</P> <P><B>Highlights</B></P> <P> <UL> <LI> CdSe@ZnS/ZnS QDs are synthesized and first applied for bioimaging. </LI> <LI> mPEG-PAEA-DDA copolymer showed pH-responsive property and the hydrolysis stability. </LI> <LI> CM-QDs-PEG-PAEA-DDA exhibited lower toxicity and higher fluorescent intensity. </LI> <LI> CM-QDs-PEG-PAEA-DDA has ability to target image for acidic brain ischemic area. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Inhibition of α-glucosidase by 2-thiobarbituric acid: Molecular dynamics simulation integrating parabolic noncompetitive inhibition kinetics

Qin, Xiu-Yuan,Lee, Jinhyuk,Zheng, Li,Yang, Jun-Mo,Gong, Yan,Park, Yong-Doo Elsevier 2018 Process biochemistry Vol.65 No.-

<P><B>Abstract</B></P> <P>The phenomenon of α-glucosidase inhibition has attracted the attention of researchers due to its association with type 2 diabetes treatment in humans. In this study, we found that 2-thiobarbituric acid (TBA) induces complex inhibition of α-glucosidase using kinetics tests and molecular dynamics (MD) simulations. Computational MD and docking simulations demonstrate that TBA interacts with three residues on active sites of α-glucosidase such as Met69, Arg212, and His348. These biochemical tests indicate that TBA reversibly inhibits α-glucosidase in a parabolic noncompetitive manner (<I>IC</I> <SUB>50</SUB> =17.13±1.14mM; <I>K</I> <SUB>i</SUB> =13.25±0.56mM) and that this inhibition is accompanied by a biphasic kinetic process. The tertiary conformational changes were not synchronized with TBA inhibition but we observed hydrophobic disruption after inactivation at higher concentrations of TBA. Our results provide insight into the functional roles of residues located at the active sites of α-glucosidase, and we suggest that compounds similar to TBA (heterocyclic compounds) targeting the key residues of active sites are potential α-glucosidase inhibitors.</P> <P><B>Highlights</B></P> <P> <UL> <LI> 2-Thiobarbituric acid (TBA) induces complex inhibition of α-glucosidase. </LI> <LI> Computational MD simulations demonstrate that TBA interacts with Met69, Arg212, and His348. </LI> <LI> TBA reversibly inhibits α-glucosidase in a parabolic noncompetitive manner (<I>IC</I> <SUB>50</SUB> =17.13±1.14mM; <I>K</I> <SUB>i</SUB> =13.25±0.56mM). </LI> <LI> The high dose of TBA induces hydrophobic disruption after inactivation. </LI> <LI> Heterocyclic compounds targeting the key residues of active sites are potential α-glucosidase inhibitors. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Hypoglycemic triterpenes from <i>Gynostemma pentaphyllum</i>

Wang, Jun,Ha, Thi Kim Quy,Shi, Yan-Ping,Oh, Won Keun,Yang, Jun-Li Elsevier 2018 Phytochemistry Vol.155 No.-

<P><B>Abstract</B></P> <P>To search for bioactive gypenosides and their analogues, a saponin enriched fraction and its hydrolyzate from <I>Gynostemma pentaphyllum</I> were phytochemically investigated. Fractionation by diverse chromatographic methods, including HPLC, Sephadex LH-20, silica gel, and C18 reverse phase silica gel, led to the isolation and purification of twelve triterpenes, including five undescribed and seven known. The chemical structures of all compounds were determined as analyzed by nuclear magnetic resonance (NMR), high resolution mass spectrometry (HR-MS), infrared spectrum (IR), optical rotation, and chemical transformations. Among all isolates, nine compounds possessed a rare dammarane triterpenoid framework with A-ring modified. The relative configurations of three compounds were determined by 2D NMR for the first time. The absolute configurations of four compounds were determined by the modified Mosher's method. Two of all isolated compounds significantly enhanced 2-deoxy-2-[(7-nitro-2,1,3-benzoxadiazol-4-yl)amino]-D-glucose (2-NBDG) uptake and Glucose Transporter 4 (GLUT4) translocation via activating the AMP-activated protein kinase (AMPK) and acetyl-CoA carboxylase (ACC) signaling pathway. This study provided the potential candidates for the development of antidiabetic agents.</P> <P><B>Highlights</B></P> <P> <UL> <LI> <I>Gynostemma pentaphyllum</I> is a traditional medicinal and edible plant in China. </LI> <LI> Five undescribed triterpenes were isolated. </LI> <LI> The modified Mosher's method was used to determine the absolute configurations. </LI> <LI> Their hypoglycemic activity was evaluated in differentiated 3T3-L1 adipocytes. </LI> <LI> This study provided the potential candidates for antidiabetic agents. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>Five undescribed and nine known triterpenes were isolated from the hydrolyzate and extract of <I>Gynostemma pentaphyllum.</I> Their hypoglycemic activity was evaluated.</P> <P>[DISPLAY OMISSION]</P>

No Association Between the USP7 Gene Polymorphisms and Colorectal Cancer in the Chinese Han Population

Li, Xin,Wang, Yang,Li, Xing-Wang,Liu, Bao-Cheng,Zhao, Qing-Zhu,Li, Wei-Dong,Chen, Shi-Qing,Huang, Xiao-Ye,Yang, Feng-Ping,Wang, Quan,Wang, Jin-Fen,Xiao, Yan-Zeng,Xu, Yi-Feng,Feng, Guo-Yin,Peng, Zhi-Ha Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.5

Colorectal cancer (CRC), now the third most common cancer across the world, is known to aggregate in families. USP7 is a very important protein with an important role in regulating the p53 pathway, which is critical for genomic stability and tumor suppression. We here genotyped eight SNPs within the USP7 gene and conducted a case-control study in 312 CRC patients and 270 healthy subjects in the Chinese Han population. No significant associations were found for any single SNP and CRC risk. Our data eliminate USP7 as a potential candidate gene towards for CRC in the Han Chinese population.

Effect of Glutamate on the Vestibulo-Solitary Projection after Sodium Nitroprusside-Induced Hypotension in Conscious Rats

Li, Li-Wei,Ji, Guang-Shi,Yang, Yan-Zhao,Ameer, Abdul Nasir,Kim, Min Sun,Park, Byung Rim,Jin, Yuan-Zhe The Korean Society of Pharmacology 2015 The Korean Journal of Physiology & Pharmacology Vol.19 No.3

Orthostatic hypotension is most common in elderly people, and its prevalence increases with age. Attenuation of the vestibulo-sympathetic reflex (VSR) is commonly associated with orthostatic hypotension. In this study, we investigated the role of glutamate on the vestibulo-solitary projection of the VSR pathway to clarify the pathophysiology of orthostatic hypotension. Blood pressure and expression of both pERK and c-Fos protein were evaluated in the nucleus tractus solitarius (NTS) after microinjection of glutamate into the medial vestibular nucleus (MVN) in conscious rats with sodium nitroprusside (SNP)-induced hypotension that received baroreceptor unloading via sinoaortic denervation (SAD). SNP-induced hypotension increased the expression of both pERK and c-Fos protein in the NTS, which was abolished by pretreatment with glutamate receptor antagonists (MK801 or CNQX) in the MVN. Microinjection of glutamate receptor agonists (NMDA or AMPA) into the MVN increased the expression of both pERK and c-Fos protein in the NTS without causing changes in blood pressure. These results indicate that both NMDA and AMPA receptors play a significant role in the vestibulo-solitary projection of the VSR pathway for maintaining blood pressure, and that glutamatergic transmission in this projection might play a key role in the pathophysiology of orthostatic hypotension.

Phospholipid and Fatty Acid Composition in Leaves and Roots of Ten Autumn Chrysanthemum Cultivars Grown at Low Temperature

Yan Li,Yonghua Li,Pan Yang,Hua’ao Zhang,Dan He 한국원예학회 2017 Horticulture, Environment, and Biotechnology Vol.58 No.4

The objective of this study was to evaluate the relationship between cold hardiness and phospholipid andfatty acid content in leaves and roots of chrysanthemum, and to explore cold resistance mechanisms of chrysanthemumin order to provide a theoretical basis for selecting and breeding a new cold-resistant cultivar. We analyzed thephospholipid and fatty acid components in leaves and roots of 10 autumn chrysanthemum cultivars including sixearly-flowering cultivars and four late-flowering cultivars. We determined the content of phosphatidyl ethanolamine(PE), phosphatidyl choline (PC), phosphatidyl serine (PS), phosphatidyl glycerol (PG), myristic acid (C14:0), palmiticacid (C16:0), stearic acid (C18:0), docosanoic acid (C22:0), oleic acid (C18:1), linoleic acid (C18:2), and linolenic acid(C18:3) in leaves and roots of chrysanthemum seedlings grown at 16C and 5C. The cultivars had different responsesto low temperature that included changes in the cell membrane composition in leaves and roots. The main phospholipidin leaves and roots of chrysanthemum was PE, and the main saturated fatty acid was palmitic acid. Amongunsaturated fatty acids, linolenic acid was found in leaves, whereas oleic acid and linoleic acid were present in theroots. Based on the unsaturated fatty acid content and the ratio of unsaturated to saturated fatty acids in leaves, theearly-flowering cultivars ‘Tan Xiang Shi Zi’ and ‘Tong Que Chun Shen’ and the late-flowering cultivars ‘Guan DongXin Xia’ and ‘Yun Long Feng Wu’ were classified as strongly cold tolerant, while the early-flowering cultivar ‘JinFeng Ling’ and the late-flowering cultivar ‘Mo Bao’ were weakly cold tolerant.