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Single crystal growth and electrochemical studies of garnet-type fast Li-ion conductors

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Tungsten 2022年第4期4卷 263-268页

作者： Yi-Tian Wang Xi Chen Department of Electrical and Computer Engineering University of CaliforniaRiversideCA92521USA

All-solid-state batteries have attracted much attention due to their improved safety and higher energy density as compared to the conventional *** to the excellent chemical stability against lithium metal and relatively high ionic conductivity at room-temperature,garnet-type fast lithium ion conductors with three-dimensional lithium ion transport channels are promising solid electrolytes for all-solid-state *** order to better understand the intrinsic lithium-ion transport mechanisms and prevent lithium dendrite formation,it is desired to investigate single-crystal solid *** this perspective,we review several methods reported to grow single crystals of garnet-type *** and cons of different growth methods are ***,we introduce some case studies on electrochemical properties of garnet-type single *** addition,we provide some perspectives about potential research directions of single-crystal solid electrolytes for all-solid-state batteries.

关键词： Solid electrolyte Single crystal Garnet-type lithium-ion conductor All-solid-state battery Crystal growth

Identification and Preliminary Characterization of a New Chemical Affecting Glucosyltransferase Activities Involved in Plant Cell Wall Biosynthesis

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Molecular Plant 2008年第6期1卷 977-989页

作者： Olga Zabotina Erik Maim Georgia Drakakaki Vincent Bulone Natasha Raikhel Institute for Integrative Genome Biology Center for Plant Cell Biology and Department of Botany and Plant Sciences University of California Riverside CA92521 USA School of Biotechnology Royal Institute of Technology (KTH) AlbaNova University Center Stockholm SE-106 91 Sweden Present address: Department of Biochemistry Biophysics and Molecular Biology Iowa State University Ames IA 50014 USA

Chemical genetics as a part of chemical genomics is a powerful and fast developing approach to dissect biological processes that may be difficult to characterize using conventional genetics because of gene redundancy or lethality and, in the case of polysaccharide biosynthesis, plant flexibility. Polysaccharide synthetic enzymes are located in two main compartments--the Golgi apparatus and plasma membrane-and can be studied in vitro using membrane fractions. Here, we first developed a high-throughput assay that allowed the screening of a library of chemicals with a potential effect on glycosyltransferase activities. Out of the 4800 chemicals screened for their effect on Golgi glucosyltransferases, 66 compounds from the primary screen had an effect on carbohydrate biosynthesis. Ten of these compounds were confirmed to inhibit glucose incorporation after a second screen. One compound exhibiting a strong inhibition effect （ID 6240780 named chemical A） was selected and further studied. It reversibly inhibits the transfer of glucose from UDP-glucose by Golgi membranes, but activates the plasma membrane-bound callose synthase. The inhibition effect is dependent on the chemical structure of the compound, which does not affect endomembrane morphology of the plant cells, but causes changes in cell wall composition. Chemical A represents a novel drug with a great potential for the study of the mechanisms of Golgi and plasma membrane-bound glucosyltransferases.

关键词： cell walls callose synthase chemical screening and identification glycosyltransferase Golgi plasma membrane

Regulation of the SQUAMOSA PROMOTER-BINDING PROTEIN-LIKE genes/microRNA 156 Module by the Homeodomain Proteins PENNYWISE and POUND-FOOLISH in Arabidopsis

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Molecular Plant 2011年第6期4卷 1123-1132页

作者： Shruti Lal Leo Bryan Pacis Harley M.S. Smith Genetics Genomics and Bioinformatics Graduate Program University of California Riverside CA 92521 USA Center for Plant Cell Biology Institute of Integrative Genome Biology Department of Botany and Plant Sciences University of California Riverside CA 92521 USA

The morphology of inflorescences is regulated in part by the temporal and spatial events that regulate flower specification. In Arabidopsis, an endogenous flowering time pathway mediated by a subset of SQUAMOSA PROMOTER- BINDING PROTEIN-LIKE （SPL） transcription factors, including SPL3, SPL4, and SPL5, function to specify flowers by activating floral meristem identity genes. During shoot development, SPL3, SPL4, and SPL5 are post-transcriptionally regulated by microRNA156 （miR156）. The photoperiod regulated florigenic signal, FLOWERING LOCUS T （FT）, promotes floral induction, in part by activating SPL3, SPL4, and SPL5. In turn, these SPLs function in parallel with FT to specify flower meristems. Two related BELLl-like homeobox genes PENNYWISE （PNY） and POUND-FOOLISH （PNF） expressed in the shoot apical meristem are absolutely required for the specification of floral meristems. Genetic studies show that the floral specification function of FT depends upon PNYand PNF; however, the interplay between these homeodomain proteins and SPLs is not known. In this manuscript, we show that the photoperiodic floral induction of SPL3, SPL4, and SPL5 is dependent upon PNY and PNE Further, PNY and PNF also control SPL3, SPL4, and SPL5 expression by negatively regulating miR156. Lastly, ectopic expres- sion of SPL4 partially rescues the pny pnf non-flower-producing phenotype, while overexpression of SPL3 or SPL5 in pny pnf plants was unable to restore flower specification. These results suggest that：（1） SPL3, SPL4, and SPL5 function is dependent upon PNY and PNF, or （2） expression of multiple SPLs is required for floral specification in pny pnf plants.

关键词： Development meristem homeodomain flowering microRNA.

Lithography-Free Fabrication of High Quality Substrate- Supported and Freestanding Graphene Devices

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Nano Research 2010年第2期3卷 98-102页

作者： Wenzhong Bao Gang Liu Zeng Zhao Hang Zhang Dong Yan Aparna Deshpande Brian LeRoy Chun Ning Lau Department of Physics and Astronomy University of CaliforniaRiversideCA 92521USA Center for Nanoscale Science and Engineering University of CaliforniaRiversideCA 92521USA Department of Physics University of ArizonaTucsonAZ 85721USA

We present a lithography-free technique for fabrication of clean,high quality graphene *** technique is based on evaporation through hard Si shadow masks,and eliminates contaminants introduced by lithographical *** demonstrate that devices fabricated by this technique have significantly higher mobility values than those obtained by standard electron beam *** obtain ultra-high mobility devices,we extend this technique to fabricate suspended graphene samples with mobilities as high as 120000 cm^(2)/(V·s).

关键词： Suspended graphene shadow mask mobility lithography-free e-beam evaporation

How two helicases work together within the TFIIH complex, a perspective from structural studies of XPB and XPD helicases

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Frontiers in Biology 2013年第4期8卷 363-368页

作者： Li FAN Department of Biochemistry University of California at Riverside Riverside CA 92521 USA

Xeroderma pigmentosum group B （XPB） and D （XPD） are two DNA helicases inside the transcription factor TFIIH complex required for both transcription and DNA repair. The importance of these helicases is underscored by the fact that mutations of XPB and XPD cause diseases with extremely high sensitivity to UV-light and high risk of cancer, premature aging, etc. This mini-review focuses on recent developments in both structural and functional characterization of these XP heficases to illustrate their distinguished biological roles within the architectural restriction of the TFIIH complex. In particular, molecular mechanisms of DNA unwinding by these helicases for promoter opening during transcription initiation and bubble-creation around the lesion during DNA repair are described based on the integration of the crystal structures of XPB and XPD helicases into the architecture of the TFIIH complex.

关键词： XPB XPD TFIIH helicase DNA repair nucleotide excision repair Wanscription

An Autophosphorylation Site of the Protein Kinase SOS2 Is Important for Salt Tolerance in Arabidopsis

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Molecular Plant 2009年第1期2卷 183-190页

作者： Hiroaki Fujii Jian-Kang Zhu Department of Botany and Plant Sciences 2150 Batchelor Hall University of California Riverside CA 92521 USA

The protein kinase SOS2 （Salt Overly Sensitive 2） is essential for salt-stress signaling and tolerance in Arabidopsis. SOS2 is known to be activated by calcium-SOS3 and by phosphorylation at its activation loop. SOS2 is autophosphorylated in vitro, but the autophosphorylation site and its role in salt tolerance are not known. In this study, we identified an autophosphorylation site in SOS2 and analyzed its role in the responses of Arabidopsis to salt stress. Mass spectrometry analysis showed that Ser 228 of SOS2 is autophosphorylated. When this site was mutated to Ala, the autophosphorylation rate of SOS2 decreased. The substrate phosphorylation by the mutated SOS2 was also less than that by the wild-type SOS2. In contrast, changing Ser228 to Asp to mimic the autophosphorylation enhanced substrate phosphorylation by SOS2. Complementation tests in a sos2 mutant showed that the S228A but not the $228D mutation partially disrupted the function of SOS2 in salt tolerance. We also show that activation loop phosphorylation at Thr168 and autophosphorylation at Ser228 cannot substitute for each other, suggesting that both are required for salt tolerance. Our results indicate that Ser 228 of SOS2 is autophosphorylated and that this autophosphorylation is important for SOS2 function under salt stress.

关键词： SOS2 autophosphorylation salt tolerance protein kinase Arabidopsis

Is ABP1 an Auxin Receptor Yet？

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Molecular Plant 2011年第4期4卷 635-640页

作者： Jing-Hua Shi Zhen-Biao Yang Center for Plant Cell Biology Department of Botany and Plant Sciences University of California Riverside CA 92521 USA

AUXIN BINDING PROTEIN 1 （ABP1） has long been proposed as an auxin receptor to regulate cell expansion. The embryo lethality of ABP1-null mutants demonstrates its fundamental role in plant development, but also hinders investigation of its involvement in post-embryonic processes and its mode of action. By taking advantage of weak alleles and inducible systems, several recent studies have revealed a role for ABP1 in organ development, cell polarization, and shape formation. In addition to its role in the regulation of auxin-induced gene expression, ABP1 has now been shown to modulate non-transcriptional auxin responses. ABP1 is required for activating two antagonizing ROP GTPase signaling pathways involved in cytoskeletal reorganization and cell shape formation, and participates in the regulation of clathrinmediated endocytosis to subsequently affect PIN protein distribution. These exciting discoveries provide indisputable evidence for the auxin-induced signaling pathways that are downstream of ABP1 function, and suggest intriguing mechanisms for ABPl-mediated polar cell expansion and spatial coordination in response to auxin.

关键词： Hormonal regulation hormone biology receptors signal transduction cell signaling.

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熔融流体与上地幔流变强度关系的实验研究

中国科学（D辑） 1997年第5期27卷 401-406页

作者：金振民金淑燕 H.W.Green Yi Zhou 中国地质大学武汉430074 University of california Riversideca92521

在上地幔温度(1300～1500K)、压力(1.5GPa)和应变速率10^(-4)～10^(-5)/s条件下对合成地幔岩进行了部分熔融变形实验研究.实验结果表明5%左右熔体使地幔岩石力学强度产生明显弱化现象,熔融流体强化了矿物颗粒边界滑移和动态重结晶作用.... 详细信息

在上地幔温度(1300～1500K)、压力(1.5GPa)和应变速率10^(-4)～10^(-5)/s条件下对合成地幔岩进行了部分熔融变形实验研究.实验结果表明5%左右熔体使地幔岩石力学强度产生明显弱化现象,熔融流体强化了矿物颗粒边界滑移和动态重结晶作用.含少量熔体液-固态双相系统上地幔岩石变形机制以高温位错蠕变为主,应力指数n为2.3,蠕变活化能为270～994kJ/mol.

关键词：上地幔熔融流体流变学高温高压实验橄榄岩

Anisotropically Shaped Magnetic/Plasmonic Nanocomposites for Information Encryption and Magnetic-Field-Direction Sensing

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Research 2018年第1期2018卷 11-23页

作者： Xiaojing Wang Ji Feng Huakang Yu Yue Jin Andrew Davidson Zhiyuan Li Yadong Yin Department of Chemistry University of CaliforniaRiversideCA 92521USA Materials Science and Engineering Program University of CaliforniaRiversideCA 92521USA School of Physics and Optoelectronics South China University of TechnologyGuangzhou 510641China

Instantaneous control over the orientation of anisotropically shaped plasmonic nanostructures allows for selective excitation of plasmon modes and enables dynamic tuning of the plasmonic *** we report the synthesis of rod-shaped magnetic/plasmonic core-shell nanocomposite particles and demonstrate the active tuning of their optical property by manipulating their orientation using an external magnetic *** further design and construct an IR-photoelectric coupling system,which generates an output voltage depending on the extinction property of the measured nanocomposite *** employ the device to demonstrate that the nanocomposite particles can serve as units for information encryption when immobilized in a polymer flm and additionally when dispersed in solution can be employed as a new type of magnetic-feld-direction sensor.

关键词： composites property shaped