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One-day thermal regime extends the lifespan in caenorhabditis elegans

cOMPUTATIONAL AND STRUcTURAL BIOTEcHNOLOGY JOURNAL 2023年 21卷 495-505页

作者： Huang, Jichang Wang, Kai Wang, Mengqing Wu, Zhen Xie, Guangjie Peng, Yuling Zhang, Yan Zhang, Xumin Shao, Zhiyong Fudan Univ Sch Life Sci Dept Biochem State Key Lab Genet Engn Shanghai 200438 Peoples R China Fudan Univ Zhongshan Hosp Dept Neurosurg State Key Lab Med NeurobiolInst Brain Sci Shanghai 200032 Peoples R China Fudan Univ Zhongshan Hosp Inst Brain Sci MOE Frontiers Ctr Brain Sci Shanghai 200032 Peoples R China Inst Geriatr Cardiovasc Dis Chengdu Med Coll Chengdu 610000 Sichuan Peoples R China Guangdong Acad Med Sci Guangdong Prov Peoples Hosp Guangdong Prov Key Lab Pathogenesis Targeted Prevent & Treatment Heart DisGuangdong C Guangzhou 510080 Guangdong Peoples R China Sichuan Univ West China Hosp Natl Clin Res Ctr Geriatr State Key Lab Biotherapy Chengdu 610041 Sichuan Peoples R China

Environmental factors, including temperature, can modulate an animal's lifespan. However, their under-lying mechanisms remain largely undefined. We observed a profound effect of temperature on the aging of caenorhabditis elegans (c. elegans) by performing proteomic analysis at different time points (young adult, middle age, and old age) and temperature conditions (20 degrees c and 25 degrees c). Importantly, although at the higher temperature, animals had short life spans, the shift from 20 degrees c to 25 degrees c for one day during early adulthood was beneficial for protein homeostasis since;it decreased protein synthesis and increased degradation. consistent with our findings, animals who lived longer in the 25 degrees c shift were also more resistant to high temperatures along with oxidative and UV stresses. Furthermore, the lifespan extension by the 25 degrees c shift was mediated by three important transcription factors, namely FOXO/DAF-16, HSF-1, and HIF-1. We re-vealed an unexpected and complicated mechanism underlying the effects of temperature on aging, which could potentially aid in developing strategies to treat age-related diseases. Our data are available in ProteomeXchange with the identifier PXD024916.(c) 2022 The Authors. Published by Elsevier B.V. on behalf of Research Network of computational and Structural Biotechnology. This is an open access article under the cc BY-Nc-ND license (http://***/licenses/by-nc-nd/4.0/).

关键词： Lifespan Temperature c elegans Proteostasis DAF-16 HSF-1 HIF-1

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Field enhancement assisted graphene-based microring modulator for high modulation depth

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IET OPTOELEcTRONIcS 2020年第6期14卷 391-398页

作者： Joshi, Swati Kaushik, Brajesh Kumar Indian Inst Technol Roorkee Dept Elect & Commun Engn Microelect & VLSI Grp Roorkee 247667 Uttarakhand India

This study aims at optimising the graphene coverage in a microresonator for the design of an efficient modulator by using a combination of graphene induced losses and phase shift. The graphene integration in the ring can provide tunability by means of altering the loss and coupling coefficient by changing the graphene coverage or its chemical potential. The fundamental parameters of graphene integrated all-pass ring resonator are extracted based on the transmission characteristics using finite-difference time-domain method. As compared to conventional graphene-oxide-semiconductor straight waveguide, graphene integrated on an all-pass ring resonator shows enhanced optical absorption and phase shift due to field enhancement factor. A modulator based on graphene tunable loss and phase shift is investigated taking into account the field enhancement factor. For 1.55 mu m radiation and ring radius of 3.75 mu m with 22% graphene coverage, a maximum modulation depth of 12.6 dB is demonstrated based on electrostatic control of graphene chemical potential. The proposed modulator can feature operational speed in the range of 10 GHz that is useful in a variety of electro-optic applications.

关键词： micro-optics optical modulation integrated optics graphene optical resonators optical tuning finite difference time-domain analysis micromechanical resonators optical losses light absorption light transmission micro-optomechanical devices optical design techniques field enhancement factor graphene tunable loss phase shift graphene coverage graphene chemical potential modulation depth efficient modulator graphene induced losses coupling coefficient finite-difference time-domain method optical absorption field enhancement assisted graphene-based microring modulator fundamental parameters graphene integrated all-pass ring resonator transmission characteristics ring radius electrostatic control microresonator radius 3 75 mum wavelength 1 55 mum c

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Magnetic molecular materials

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cURRENT OPINION IN SOLID STATE & MATERIALS ScIENcE 1996年第2期1卷 192-198页

作者： Gatteschi, D Department of Chemistry University of Florence Via Maragliano 77 50144 Florence Italy

Magnetic molecular materials are actively investigated along two different but complementary lines of research, that of designing bulk magnets with permanent magnetization, possibly with high critical temperatures, and that of synthesizing large, but finite, magnetic clusters, which can be considered as small magnetic particles of nanoscale size. In both areas the techniques of molecular chemistry are employed to assemble organic, organometallic and inorganic building blocks into complex architectures. Major advances have been achieved, ranging from the development of magnets with a critical temperature higher than room temperature to the use of biological approaches to test quantum tunneling of the magnetization.

关键词： T c critical temperature

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Nicotine Upregulates coaggregation of candida albicans and Streptococcus mutans

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JOURNAL OF PROSTHODONTIcS-IMPLANT ESTHETIc AND REcONSTRUcTIVE DENTISTRY 2019年第7期28卷 790-796页

作者： Ashkanane, Ali Gomez, Grace F. Levon, John Windsor, L. Jack Eckert, George J. Gregory, Richard L. Indiana Univ Sch Dent Dept Prosthodont Indianapolis IN 46202 USA Indiana Univ Sch Dent Dept Biomed & Appl Sci 1121 W Michigan St Indianapolis IN 46202 USA Indiana Univ Dept Biostat Sch Med Indianapolis IN 46202 USA

Purpose Denture stomatitis is a condition of painless inflammation of denture-bearing mucosa. Reports indicate that nicotine, the major psychoactive ingredient in tobacco, increases growth of Streptococcus mutans and candida albicans in denture biofilm. The purpose of this study was to determine the in vitro effects of nicotine on coaggregation of c. albicans with S. mutans. Material and Methods c. albicans strain ATcc 10231, S. mutans strain UA159 (ATTc 700610), and nicotine dilutions (ranging from 0 to 32 mg/ml) were used for this study. Both microorganisms were grown for 24 hours in dilutions of nicotine (0 to 32 mg/ml) made in tryptic soy broth (TSB) or TSB supplemented with 1% sucrose (TSBS;S. mutans) or yeast peptone dextrose broth (YPD;c. albicans). Suspensions of the nicotine-treated cells were prepared, mixed together and incubated for up to 24 hours to determine if there was an increase in coaggregation of nicotine-treated cells compared to the no nicotine control cells. Qualitative analysis of coaggregation was performed using a visual aggregation assay and light microscopic observation. A spectrophotometric assay was used to provide a quantitative analysis of the coaggregation. Results The visual aggregation assay indicated a significant increase in coaggregation between c. albicans and S. mutans with increasing incubation time (0 to 24 hours) and nicotine concentrations (0 to 4 mg/ml). Microbial growth in nicotine at 4 mg/ml demonstrated a significant increase in coaggregation after 24 hours of incubation. The numbers of coaggregated S. mutans/c. albicans cells exhibited a significant increase with incubation time and nicotine concentrations when the samples were examined microscopically. More coaggregation of S. mutans and c. albicans was observed with incubation time and increased nicotine compared to the 0 mg/ml nicotine group. There was a noticeable increase of coaggregation when cells were grown in TSBS compared to TSB. Absorbance of nicotine-treat

关键词： coaggregation nicotine denture stomatitis c albicans S mutans

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Organic carbon fluxes from the upper Yangtze basin: an example of the Longchuanjiang River, china

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HYDROLOGIcAL PROcESSES 2012年第11期26卷 1604-1616页

作者： Lu, X. X. Li, Siyue He, Min Zhou, Yue Li, Li Ziegler, Alan D. Natl Univ Singapore Dept Geog Singapore 117570 Singapore Yunnan Univ Finance & Econ Global Change & Watershed Management Ctr Kunming 650221 Peoples R China

To investigate the effects of anthropogenic activity, namely, land use change and reservoir construction, on particulate organic carbon (POc) transport, we collected monthly water samples during September 2007 to August 2009 from the Longchuanjiang River to understand seasonal variations in the concentrations of organic carbon species and their sources and the yield of organic and inorganic carbon from the catchment in the Upper Yangtze basin. The contents of riverine POc, total organic carbon and total suspended sediment (TSS) changed synchronously with water discharge, whereas the contents of dissolved organic carbon had a small variation. The POc concentration in the suspended sediment decreased non-linearly with increasing TSS concentration. Higher molar c/N ratio of particulate organic matter (average 77) revealed that POc was dominated by terrestrially derived organic matter in the high flows and urban wastewaters in the low flows. The TSS transported by this river was 2.7?x?105?t/yr in 2008. The specific fluxes of total organic carbon and dissolved inorganic carbon (DIc) were 5.6 and 6?t/km2/yr, respectively, with more than 90% in the high flow period. A high carbon yield in the catchment of the upper Yangtze was due to human-induced land use alterations and urban wastes. consistent with most rivers in the monsoon climate regions, the dissolved organic carbonPOc ratio of the export flux was low (0.41). Twenty-two percent (0.9?t/km2/yr) of POc out of 4?t/km2/yr was from autochthonous production and 78% (3.1?t/km2/yr) from allochthonous production. The annual sediment load and hence the organic carbon flux have been affected by environmental alterations of physical, chemical and hydrological conditions in the past 50?years, demonstrating the impacts of human disturbances on the global and local carbon cycling. Finally, we addressed that organic carbon flux should be reassessed using adequate samples (i.e. at least two times in low-flow month, four times in high

关键词： dissolved organic carbon particulate organic carbon c N ratio water discharge sediment loads Longchuanjiang Yangtze River

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Pressure-induced structural phase transition in transition metal carbides TMc (TM = Ru, Rh, Pd, Os, Ir, Pt): a DFT study

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PHILOSOPHIcAL MAGAZINE 2018年第7期98卷 541-559页

作者： Manikandan, M. Rajeswarapalanichamy, R. Iyakutti, K. NMSSVN Coll Dept Phys Madurai Tamil Nadu India SRM Univ Dept Phys & Nanotechnol Chennai Tamil Nadu India

First-principles calculations based on density functional theory was performed to analyse the structural stability of transition metal carbides TMc (TM=Ru, Rh, Pd, Os, Ir, Pt). It is observed that zinc-blende phase is the most stable one for these carbides. Pressure-induced structural phase transition from zinc blende to NiAs phase is predicted at the pressures of 248.5 GPa, 127 GPa and 142 GPa for Osc, Irc and Ptc, respectively. The electronic structure reveals that Ruc exhibits a semiconducting behaviour with an energy gap of 0.7056eV. The high bulk modulus values of these carbides indicate that these metal carbides are super hard materials. The high B/G value predicts that the carbides are ductile in their most stable phase.

关键词： c Density functional theory D crystal structure D Phase transition D Electronic structure D Mechanical properties

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Achievement of high-purity carbon nanofibres via peeling process

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MIcRO & NANO LETTERS 2020年第14期15卷 1038-1040页

作者： Zhao, Xianglong chen, Bin Shandong Jianzhu Univ Sch Sci Jinan 250101 Peoples R China Chinese Acad Sci Inst Solid State Phys Key Lab Mat Phys Hefei 230031 Peoples R China Chinese Acad Sci Inst Solid State Phys Anhui Key Lab Nanomat & Nanotechnol Hefei 230031 Peoples R China

The authors report a facile approach to high-purity carbon nanofibres (cNFs), by performing chemical vapour deposition on aluminium foils loaded with metal (nickel or cobalt) nitrates, and then peeling the as-grown cNFs off. The growth of cNFs was catalysed by metal nanoparticles and followed bottom-growth mechanism, and the high-purity cNFs were achieved due to detachment of cNFs from their underlying metal nanoparticles during the peeling process. This approach may pave a new way for the controlled and scalable synthesis of high-purity carbon materials.

关键词： chemical vapour deposition carbon fibres nanoparticles nanofibres adhesion nanofabrication metal nanoparticles peeling process high-purity carbon nanofibres chemical vapour deposition aluminium foils bottom-growth mechanism c

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Electrochemical capacitors utilizing low surface area carbon fiber

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IEEE AEROSPAcE AND ELEcTRONIc SYSTEMS MAGAZINE 1997年第7期12卷 27-30页

作者： Lipka, SM Department of Occan Engineegine Florida Atlantic University Boca Raton FL USA

The performance of electrochemical capacitors containing different commercial carbon fibers is reviewed. High specific capacitance (ca. 300 F/g) is obtained with low surface area carbon fiber (< 1 m(2)/g) using a proprietary activation process. capacitance is primarily achieved through pseudocapacitance resulting from surface functional groups. The performance of these devices is dependent on the type of carbon fiber, its carbon content, aspect ratio and microstructure. These devices can achieve high cycle life (ca. 100k) without significant loss in capacitance.

关键词： capacitance carbon fibres electrochemical electrodes electrolytic capacitors life testing c activation process aspect ratio carbon fibers cycle life double-layer capacitors electrochemical capacitors microstructure pseudocapacitance specific capacitance specific capacitance capacitance electric double-layer capacitor carbon fiber Life testing electrochemical capacitors Electrolytic capacitors cycle life ASPEcT RATIO Electrochemical electrodes Microstructure

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Graphene-based THz modulator analysed by equivalent circuit model

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MIcRO & NANO LETTERS 2016年第8期11卷 439-442页

作者： Xiao, Binggang chen, Jing Xie, Zhiyi Xiao, Sanshui Ji Liang Univ China Coll Informat Engn Hangzhou 310018 Zhejiang Peoples R China Tech Univ Denmark Dept Photon Engn DK-2800 Lyngby Denmark

A terahertz (THz) modulator based on graphene is proposed and analysed by use of equivalent transmission line of a homogeneous medium and the local anisotropic model of the graphene conductivity. The result calculated by the equivalent circuit is consistent with that obtained by Fresnel transfer matrices. For the modulator proposed here, when the frequency of carrier wave is 0.6 THz, the theoretical analysis indicates that the modulation bandwidth is 55.5 kHz and the modulation depth is 81.3% for voltage change from 0 to 50 V.

关键词： terahertz wave devices equivalent circuits modulators graphene graphene based THz modulator equivalent circuit model equivalent transmission line graphene conductivity Fresnel transfer matrices bandwidth 55 5 kHz c

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characterisation of a carbon nanotube random network conjugated by semiconductor nanoparticles with defined nanometre-scaled gaps

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MIcRO & NANO LETTERS 2012年第8期7卷 753-756页

作者： Kumagai, S. Okamoto, N. Kobayashi, M. Yamashita, I. Toyota Technol Inst Dept Adv Sci & Technol Nagoya Aichi 468 Japan Nara Inst Sci & Technol Grad Sch Mat Sci Nara Japan Japanese Fdn Canc Res Inst Canc Tokyo 170 Japan

Utilising a biological material, a novel cNT nanostructure conjugated by semiconductor nanoparticles (NPs) was synthesised intended for electronics devices with unprecedented properties. A peptide aptamer that has an affinity for carbonaceous materials was fused to a cage-shaped protein (LiDps) to be displayed on its outer surface. As a potential coulomb island, semiconductor NPs were synthesised within the cavity of engineered protein (NHBP-LiDps). By the affinity of the peptide aptamer, the NHBP-LiDps proteins accommodating semiconductor NPs were adhered to surround the cNTs with nanometre-scaled gaps defined by the thickness of the protein cage. Using a dielectrophoresis assembly, the random network of cNTs conjugated by the NHBP-LiDps with NP cores was formed between a pair of electrodes. Electronic characterisation was performed on the random network of cNTs conjugated with NPs. coulomb blockade was observed. When cNTs were dispatched between a pair of electrodes, ohmic characteristics were observed. Apparently, the direct contact between cNTs was avoided by the NHBP-LiDps proteins surrounding the cNTs. The results are the first steps towards revealing unique electronic properties of these cNT conjugates.

关键词： Low-dimensional structures: growth, structure and nonelectronic properties proteins nanoparticles biological material Structure of solid clusters, nanoparticles, nanotubes and nanostructured materials c electrophoresis coulomb blockade carbonaceous materials electrodes peptide aptamer nanometre scaled gap Electrochemistry and electrophoresis ohmic contacts Electrical properties of fullerenes and related materials (thin films/low-dimensional structures) cage shaped protein Electrical properties of metal-nonmetal contacts ohmic characteristics carbon nanotube random network Preparation of fullerenes and fullerene-related materials, intercalation compounds, and diamond NHBP-LiDps proteins carbon nanotubes coulomb island dielectrophoresis assembly quantum tunnelling nanofabrication semiconductor nanoparticles cNT nanostructure Methods of nanofabrication and processing

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