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Low Gate Voltage Operated Multi-emitter-dot H^+ Ion-Sensitive Gated Lateral Bipolar Junction Transistor
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作者 袁珩 张冀星 +4 位作者 张晨 张宁 徐丽霞 丁铭 Patrick J.C 《Chinese Physics Letters》 SCIE CAS CSCD 2015年第2期27-30,共4页
A low gate voltage operated multi-emitter-dot gated lateral bipolar junction transistor (BJT) ion sensor is proposed. The proposed device is composed of an arrayed gated lateral BJT, which is driven in the metal-oxi... A low gate voltage operated multi-emitter-dot gated lateral bipolar junction transistor (BJT) ion sensor is proposed. The proposed device is composed of an arrayed gated lateral BJT, which is driven in the metal-oxidesemiconductor field-effect transistor (MOSFET)-BJT hybrid operation mode. Further, it has multiple emitter dots linked to each other in parallel to improve ionic sensitivity. Using hydrogen ionic solutions as reference solutions, we conduct experiments in which we compare the sensitivity and threshold voltage of the multi-emitter-dot gated lateral BJT with that of the single-emitter-dot gated lateral BJT. The multi-emitter-dot gated lateral BJT not only shows increased sensitivity but, more importantly, the proposed device can be operated under very low gate voltage, whereas the conventional ion-sensitive field-effect transistors cannot. This special characteristic is significant for low power devices and for function devices in which the provision of a gate voltage is difficult. 展开更多
关键词 BJT MOSFET Ion-Sensitive gated Lateral Bipolar Junction Transistor Low gate voltage Operated Multi-emitter-dot H
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Effect of High-Gate-Voltage Stress on the Reverse Gated-Diode Current in LDD nMOSFET’s 被引量:2
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作者 陈海峰 郝跃 马晓华 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2008年第5期875-878,共4页
The reverse generation current under high-gate-voltage stress condition in LDD nMOSFET's is studied. We find that the generation current peak decreases as the stress time increases. We ascribe this finding to the dom... The reverse generation current under high-gate-voltage stress condition in LDD nMOSFET's is studied. We find that the generation current peak decreases as the stress time increases. We ascribe this finding to the dominating oxide trapped electrons that reduce the effective drain bias, lowering the maximal generation rate. The density of the effective trapped electrons affecting the effective drain bias is calculated with our model. 展开更多
关键词 generation current high gate voltage stress trapped electron
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Voltage gated calcium channel antibody-related neurological diseases 被引量:6
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作者 Can Ebru Bekircan-Kurt Eda DerleÇiftçi +1 位作者 Aslι Tuncer Kurne Banu Anlar 《World Journal of Clinical Cases》 SCIE 2015年第3期293-300,共8页
Voltage gated calcium channel(VGCC) antibodies are generally associated with Lambert-Eaton myasthenic syndrome. However the presence of this antibody has been associated with paraneoplastic as well as nonparaneoplasti... Voltage gated calcium channel(VGCC) antibodies are generally associated with Lambert-Eaton myasthenic syndrome. However the presence of this antibody has been associated with paraneoplastic as well as nonparaneoplastic cerebellar degeneration. Most patients with VGCC-antibody-positivity have small cell lung cancer(SCLC). Lambert-Eaton myasthenic syndrome(LEMS)is an autoimmune disease of the presynaptic part of the neuromuscular junction. Its classical clinical triadis proximal muscle weakness, areflexia and autonomic dysfunction. Fifty to sixty percent of LEMS patients have a neoplasia, usually SCLC. The co-occurrence of SCLC and LEMS causes more severe and progressive disease and shorter survival than non-paraneoplastic LEMS. Treatment includes 3,4 diaminopyridine for symptomatic purposes and immunotherapy with prednisolone, azathioprine or intravenous immunoglobulin in patients unresponsive to 3,4 diaminopyridine. Paraneoplastic cerebellar degeneration(PCD) is a syndrome characterized with severe, subacute pancerebellar dysfunction. Serum is positive for VGCC antibody in 41%-44% of patients, usually with the co-occurrence of SCLC. Clinical and electrophysiological features of LEMS are also present in 20%-40% of these patients. Unfortunately, PCD symptoms do not improve with immunotherapy. The role of VGCC antibody in the immunopathogenesis of LEMS is well known whereas its role in PCD is still unclear. All patients presenting with LEMS or PCD must be investigated for SCLC. 展开更多
关键词 voltage gated calcium channel antibody Lambert-Eaton myasthenic syndrome Paraneoplastic cerebellar degeneration Onconeural antibodies Small cell lung cancer
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Realization of an 850V High Voltage Half Bridge Gate Drive IC with a New NFFP HVI Structure
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作者 Ming Qiao Hong-Jie Wang Ming-Wei Duan Jian Fang Bo Zhang Zhao-Ji Li 《Journal of Electronic Science and Technology of China》 2007年第4期328-331,共4页
A NFFP HVI structure which implements high breakdown voltage without using additional FFP and process steps is proposed in this paper. An 850 V high voltage half bridge gate drive IC with the NFFP HVI structure is exp... A NFFP HVI structure which implements high breakdown voltage without using additional FFP and process steps is proposed in this paper. An 850 V high voltage half bridge gate drive IC with the NFFP HVI structure is experimentally realized using a thin epitaxial BCD process. Compared with the MFFP HVI structure, the proposed NFFP HVI structure shows simpler process and lower cost. The high side offset voltage in the half bridge gate drive IC with the NFFP HVI structure is almost as same as that with the self-shielding structure. 展开更多
关键词 High voltage interconnection multiple floating field plate no floating field plate SELF-SHIELDING high voltage half bridge gate drive IC.
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New DDSCR structure with high holding voltage for robust ESD applications 被引量:1
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作者 Zi-Jie Zhou Xiang-Liang Jin +1 位作者 Yang Wang Peng Dong 《Chinese Physics B》 SCIE EI CAS CSCD 2021年第3期529-539,共11页
A novel dual direction silicon-controlled rectifier(DDSCR)with an additional P-type doping and gate(APGDDSCR)is proposed and demonstrated.Compared with the conventional low-voltage trigger DDSCR(LVTDDSCR)that has posi... A novel dual direction silicon-controlled rectifier(DDSCR)with an additional P-type doping and gate(APGDDSCR)is proposed and demonstrated.Compared with the conventional low-voltage trigger DDSCR(LVTDDSCR)that has positive and negative holding voltages of 13.371 V and 14.038 V,respectively,the new DDSCR has high positive and negative holding voltages of 18.781 V and 18.912 V in a single finger device,respectively,and it exhibits suitable enough positive and negative holding voltages of 14.60 V and 14.319 V in a four-finger device for±12-V application.The failure current of APGDDSCR is almost the same as that of LVT-DDSCR in the single finger device,and the four-finger APGDDSCR can achieve positive and negative human-body model(HBM)protection capabilities of 22.281 kV and 23.45 kV,respectively,under 40-V voltage of core circuit failure,benefitting from the additional structure.The new structure can generate a snapback voltage on gate A to increase the current gain of the parasitic PNP in holding voltage.Thus,a sufficiently high holding voltage increased by the structure can ensure that a multi-finger device can also reach a sufficient holding voltage,it is equivalent to solving the non-uniform triggering problem of multi-finger device.The operating mechanism and the gate voltage are both discussed and verified in two-dimensional(2D)simulation and experiemnt. 展开更多
关键词 dual direction silicon-controlled rectifier(DDSCR) failure current snapback gate voltage simulation transmission line pulsing(TLP)
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Gate tunable Rashba spin-orbit coupling at CaZrO_(3)/SrTiO_(3)heterointerface 被引量:1
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作者 Wei-Min Jiang Qiang Zhao +10 位作者 Jing-Zhuo Ling Ting-Na Shao Zi-Tao Zhang Ming-Rui Liu Chun-Li Yao Yu-Jie Qiao Mei-Hui Chen Xing-Yu Chen Rui-Fen Dou Chang-Min Xiong Jia-Cai Nie 《Chinese Physics B》 SCIE EI CAS CSCD 2022年第6期615-619,共5页
High mobility quasi two-dimensional electron gas(2DEG)found at the CaZrO_(3)/SrTiO_(3) nonpolar heterointerface is attractive and provides a platform for the development of functional devices and nanoelectronics.Here ... High mobility quasi two-dimensional electron gas(2DEG)found at the CaZrO_(3)/SrTiO_(3) nonpolar heterointerface is attractive and provides a platform for the development of functional devices and nanoelectronics.Here we report that the carrier density and mobility at low temperature can be tuned by gate voltage at the CaZrO_(3)/SrTiO_(3) interface.Furthermore,the magnitude of Rashba spin-orbit interaction can be modulated and increases with the gate voltage.Remarkably,the diffusion constant and the spin-orbit relaxation time can be strongly tuned by gate voltage.The diffusion constant increases by a factor of~19.98 and the relaxation time is reduced by a factor of over three orders of magnitude while the gate voltage is swept from-50 V to 100 V.These findings not only lay a foundation for further understanding the underlying mechanism of Rashba spin-orbit coupling,but also have great significance in developing various oxide functional devices. 展开更多
关键词 CaZrO_(3)/SrTiO_(3) 2DEG Rashba spin-orbit coupling gate voltage
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Functional and distinct roles of Piezo2-mediated mechanotransduction in dental primary afferent neurons
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作者 Pa Reum Lee Kihwan Lee +2 位作者 Ji Min Park Shinae Kim Seog Bae Oh 《International Journal of Oral Science》 2025年第4期570-583,共14页
Piezo2,a mechanosensitive ion channel,serves as a crucial mechanotransducer in dental primary afferent(DPA)neurons and is potentially involved in hypersensitivity to mild mechanical irritations observed in dental pati... Piezo2,a mechanosensitive ion channel,serves as a crucial mechanotransducer in dental primary afferent(DPA)neurons and is potentially involved in hypersensitivity to mild mechanical irritations observed in dental patients.Given Piezo2’s widespread expression across diverse subpopulations of DPA neurons,this study aimed to characterize the mechanosensory properties of Piezo2-expressing DPA neurons with a focus on distinct features of voltage-gated sodium channels(VGSCs)and neuropeptide profiles.Using whole-cell patch-clamp recordings,we observed mechanically activated action potentials(APs)and classified AP waveforms based on the presence or absence of a hump during the repolarization phase.Single-cell reverse transcription polymerase chain reaction combined with patch-clamp recordings revealed specific associations between AP waveforms and molecular properties,including tetrodotoxin-resistant VGSCs(NaV1.8 and NaV1.9)and TRPV1 expression.Reanalysis of the transcriptomic dataset of DPA neurons identified correlations between neuropeptides—including two CGRP isoforms(α-CGRP andβ-CGRP),Substance P,and Galanin—and the expression of NaV1.8 and NaV1.9,which were linked to defined AP subtypes.These molecular associations were further validated in Piezo2+DPA neurons using fluorescence in situ hybridization.Together,these findings highlight the electrophysiological and neurochemical heterogeneity of Piezo2-expressing DPA neurons and their specialized roles in distinct mechanosensory signal transmission. 展开更多
关键词 mechanosensory properties voltage gated sodium channels mechanosensitive ion channelserves Piezo dental primary afferent neurons hypersensitivity mild mechanical irritations MECHANOTRANSDUCTION neuropeptide profilesusing
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A novel current-source management integrated circuit applied to high-voltage integrated gate commutated thyristor gate driver
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作者 Shiping Chen Zhanqing Yu +4 位作者 Jiaxu Shi Zhengyu Chen Lu Qu Jinpeng Wu Rong Zeng 《High Voltage》 2025年第3期533-545,共13页
This paper presents a fully customised integrated gate commutated thyristor(IGCT)gate driver monolithic integrated circuit(GDMIC),aiming to address the many shortcomings of traditional IGCT gate driver units composed ... This paper presents a fully customised integrated gate commutated thyristor(IGCT)gate driver monolithic integrated circuit(GDMIC),aiming to address the many shortcomings of traditional IGCT gate driver units composed of discrete components,such as the excessive number of components,low reliability,and complex development processes.The current-source driving characteristics of IGCTs pose significant technical challenges for developing fully customised integrated circuits(IC).The customised requirements of IGCT gate driver chips under various operating conditions are explored regarding functional module division,power sequencing,and chip parameter specifications.However,existing high-side(HS)driver methods exhibit limitations in functional monolithic integration and bipolar complementary metal-oxide-semiconductor compat-ibility.To address these challenges,a novel HS driving topology based on floating linear regulators is proposed.It can achieve synchronised control of multi-channel floating power transistors while supporting 100%duty cycle continuous conduction.The pro-posed GDMIC reduces the three independent HS power supplies to a single multiplexed topology,significantly decreasing circuit complexity.Experimental results validate the feasibility and performance of a 4-inch gate driver prototype based on IGCT current-source management IC,demonstrating significant advantages in reducing the number of components,enhancing device reliability,and simplifying development.The proposed GDMIC offers an innovative development path for future high-power IGCT drivers. 展开更多
关键词 high voltage integrated gate commutated thyristor gate driver fully customised integrated gate commutated thyristor gate driver monolithic integrated circuit power sequencing discrete componentssuch novel current source management integrated circuit integrated circuits ic integrated gate commutated thyristor igct gate functional module division
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Application of graphene vertical field effect to regulation of organic light-emitting transistors
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作者 Hang Song Hao Wu +2 位作者 Hai-Yang Lu Zhi-Hao Yang Long Ba 《Chinese Physics B》 SCIE EI CAS CSCD 2020年第5期473-478,共6页
The luminescence intensity regulation of organic light-emitting transistor(OLED)device can be achieved effectively by the combination of graphene vertical field effect transistor(GVFET)and OLED.In this paper,we fabric... The luminescence intensity regulation of organic light-emitting transistor(OLED)device can be achieved effectively by the combination of graphene vertical field effect transistor(GVFET)and OLED.In this paper,we fabricate and characterize the graphene vertical field-effect transistor with gate dielectric of ion-gel film,confirming that its current switching ratio reaches up to 102.Because of the property of high light transmittance in ion-gel film,the OLED device prepared with graphene/PEDOT:PSS as composite anode exhibits good optical properties.We also prepare the graphene vertical organic light-emitting field effect transistor(GVOLEFET)by the combination of GVFET and graphene OLED,analyzing its electrical and optical properties,and confirming that the luminescence intensity can be significantly changed by regulating the gate voltage. 展开更多
关键词 graphene vertical field effect transistor organic light-emitting transistor ion-gel film gate voltage regulation
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Theoretical and simulation studies on voltage-gated sodium channels 被引量:1
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作者 Yang Li Haipeng Gong 《Protein & Cell》 SCIE CAS CSCD 2015年第6期413-422,共10页
Voltage-gated sodium (Nav) channels are indispensable membrane elements for the generation and propagation of electric signals in excitable cells. The successes in the crystallographic studies on prokaryotic Nay cha... Voltage-gated sodium (Nav) channels are indispensable membrane elements for the generation and propagation of electric signals in excitable cells. The successes in the crystallographic studies on prokaryotic Nay chan- nels in recent years greatly promote the mechanistic investigation of these proteins and their eukaryotic counterparts. In this paper, we mainly review the pro- gress in computational studies, especially the simula- tion studies, on these proteins in the past years. 展开更多
关键词 voltage-gated sodium channels molecular dynamics simulation ion permeation ionselectivity voltage gating
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Antimicrobial Activity of Purified Toxins from Crossopriza lyoni (Spider) against Certain Bacteria and Fungi
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作者 Ravi Kumar Gupta Ravi Kant Upadhyay 《Journal of Biosciences and Medicines》 2016年第8期1-9,共9页
Toxins from spider venom Crossopriza lyoni were subjected to purify on a Sepharose CL-6B 200 column. These were investigated for its antibacterial and antifungal activity against 13 infectious microbial pathogenic str... Toxins from spider venom Crossopriza lyoni were subjected to purify on a Sepharose CL-6B 200 column. These were investigated for its antibacterial and antifungal activity against 13 infectious microbial pathogenic strains. Antimicrobial susceptibility was determined by using paper disc diffusion and serial micro-dilution assays. Triton X-100 (0.1%) proved to be a good solubilizing agent for toxin/proteins. Higher protein solubilization was observed in the supernatant than in the residue, except TCA. The elution pattern of purified and homogenized sting glands displayed two major peaks at 280 nm. First one was eluted in fraction no. 43 - 51 while second one after fraction no. 61 - 90. From gel filtration chromatography total yield of protein obtained was 67.3%. From comparison of gel chromatographs eluted toxins peptide molecular weight was ranging from 6.2 - 64 kD. Toxin peptides have shown lower MIC values i.e. 7.5 - 15 μg/ml against K. pneumoniae, E. coli, L. acidophilus, B. cereus;against S. aureus and M. luteus that the broad spectrum antibiotics i.e. tetracycline and ampicillin. In tests, larger inhibition zone diameter was obtained in comparison to control. Diameter of inhibition zones obtained in spider toxins at a concentration range of 197.12 - 0.96 g/ml for E. coli was 17.86 ± 0.21, Bacillus cereus 19.13 ± 0.21, L. acidophilus 16.83 ± 0.25, Micrococcus luteus 18.46 ± 0.17, S. aeurus 16.23 ± 0.19, Klebsiella pneumoniae 21.83 ± 0.16, Salmonella typhi 16.16 ± 0.21, Vibrio cholera 18.66 ± 0.21, Pseudomonas aeruginosa 18.66 ± 0.21, Aspergillus niger 22.9 ± 0.24, Candida albicans 24.66 ± 0.28, Rhizopus stolonifer 21.1 ± 0.16. Spider toxins generate cytotoxic effect on bacterial cells that results in heavy cell death. No doubt spider toxins can be used as alternate of broad spectrum antibiotics. 展开更多
关键词 Spider Toxins voltage gates Antibacterial ANTIFUNGAL Susceptibility Antimicrobials Bio-Insecticides
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Gate-tunable high-performance broadband phototransistor array of two-dimensional PtSe_(2) on SOI 被引量:4
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作者 Yexin Chen Qinghai Zhu +4 位作者 Xiaodong Zhu Yijun Sun Zhiyuan Cheng Jing Xu Mingsheng Xu 《Nano Research》 SCIE EI CSCD 2023年第5期7559-7567,共9页
Two-dimensional(2D)layered materials have attracted extensive research interest in the field of high-performance photodetection due to their high carrier mobility,tunable bandgap,stability,other excellent properties.H... Two-dimensional(2D)layered materials have attracted extensive research interest in the field of high-performance photodetection due to their high carrier mobility,tunable bandgap,stability,other excellent properties.Herein,we propose a gate-tunable,high-performance,self-driving,wide detection range phototransistor based on a 2D PtSe_(2)on silicon-oninsulator(SOI).Benefiting from the strong built-in electric field of the PtSe_(2)/Si heterostructure,the phototransistor has a fast response time(rise/fall time)of 36.7/32.6μs.The PtSe_(2)/Si phototransistor exhibits excellent photodetection performance over a broad spectral range from ultraviolet to near-infrared,including a responsivity of 1.07 A/W and a specific detectivity of 6.60×10^(9)Jones under 808 nm illumination at zero gate voltage.The responsivity and specific detectivity of PtSe_(2)/Si phototransistor at 5 V gate voltage are increased to 13.85 A/W and 1.90×10^(10) Jones under 808 nm illumination.Furthermore,the fabricated PtSe_(2)/Si phototransistor array shows excellent uniformity,reproducibility,long-term stability in terms of photoresponse performance with negligible variation between pixel cells.The architecture of present PtSe_(2)/Si on SOI platform paves a new way of a general strategy to realize high-performance photodetectors by combining the advantages of both 2D materials and conventional semiconductors which is compatible with current Si-complementary metal oxide semiconductor(CMOS)process. 展开更多
关键词 two-dimensional PtSe_(2) silicon-on-insulator(SOI) HETEROJUNCTION PHOTOTRANSISTOR gate voltage modulation
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Novel SOI double-gate MOSFET with a P-type buried layer
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作者 姚国亮 罗小蓉 +6 位作者 王琦 蒋永恒 王沛 周坤 吴丽娟 张波 李肇基 《Journal of Semiconductors》 EI CAS CSCD 2012年第5期57-60,共4页
An ultra-low specific on-resistance(R_(on,sp)) integrated silicon-on-insulator(SOI) double-gate triple RESURF(reduced surface field) n-type MOSFET(DG T-RESURF) is proposed.The MOSFET features two structures... An ultra-low specific on-resistance(R_(on,sp)) integrated silicon-on-insulator(SOI) double-gate triple RESURF(reduced surface field) n-type MOSFET(DG T-RESURF) is proposed.The MOSFET features two structures: an integrated double gates structure(DG) that combines a planar gate with an extended trench gate,and a p-type buried layer(BP) in the n-type drift region.First,the DG forms dual conduction channels and shortens the forward current path,so reducing R_(on,sp).The DG works as a vertical field plate to improve the breakdown voltage (BV) characteristics.Second,the BP forms a triple RESURF structure(T-RESURF),which not only increases the drift doping concentration but also modulates the electric field.This results in a reduced R_(on,sp) and an improved BV.Third,the extended trench gate and the BP linked with the p-body region reduce the sensitivity of the BV to position of the BP.The BV of 325 V and R_(on,sp) of 8.6 mΩ·cm^2 are obtained for the DG T-RESURF by simulation. R_(on,sp) of DG T-RESURF is decreased by 63.4%in comparison with a planar-gate single RESURF MOSFET(PG S-RESURF),and the BV is increased by 9.8%. 展开更多
关键词 SOI double gates specific on-resistance RESURF breakdown voltage
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Enhancement-mode InAlN/GaN MISHEMT with low gate leakage current
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作者 顾国栋 蔡勇 +5 位作者 冯志红 刘波 曾春红 于国浩 董志华 张宝顺 《Journal of Semiconductors》 EI CAS CSCD 2012年第6期28-30,共3页
We report an enhancement-mode InAlN/GaN MISHEMT with a low gate leakage current by a thermal oxidation technique under gate.The off-state source-drain current density is as low as~10^(17) A/mm at V_(GS)= 0 V and... We report an enhancement-mode InAlN/GaN MISHEMT with a low gate leakage current by a thermal oxidation technique under gate.The off-state source-drain current density is as low as~10^(17) A/mm at V_(GS)= 0 V and V_(DS) = 5 V.The threshold voltage is measured to be +0.8 V by linear extrapolation from the transfer characteristics.The E-mode device exhibits a peak transconductance of 179 mS/mm at a gate bias of 3.4 V.A low reverse gate leakage current density of 4.9×10^(17) A/mm is measured at V_(GS) =-15 V. 展开更多
关键词 enhancement-mode InAlN/GaN HEMT threshold voltage thermal oxidation gate leakage
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On-chip graphene photodetectors with a nonvolatile p-i-n homojunction
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作者 Ruijuan Tian Yong Zhang +15 位作者 Yingke Ji Chen Li Xianghu Wu Jianguo Wang Shuaiwei Jia Liang Liu Mingwen Zhang Yu Zhang Qiao Zhang Zhuang Xie Zhengdong Luo Duorui Gao Yan Liu Jianlin Zhao Zhipei Sun Xuetao Gan 《Light: Science & Applications》 2025年第8期2360-2368,共9页
Graphene’s unique photothermoelectric(PTE)effect,combined with its compatibility for on-chip fabrication,promises its development in chip-integrated photodetectors with ultralow dark-current and ultrafast speed.Previ... Graphene’s unique photothermoelectric(PTE)effect,combined with its compatibility for on-chip fabrication,promises its development in chip-integrated photodetectors with ultralow dark-current and ultrafast speed.Previous designs of on-chip graphene photodetectors required external electrical biases or gate voltages to separate photocarriers,leading to increased power consumption and complex circuitry.Here,we demonstrate a nonvolatile graphene p–i–n homojunction constructed on a silicon photonic crystal waveguide,which facilitates PTE-based photodetection without the need for electrical bias or gate voltages.By designing an air-slotted photonic crystal waveguide as two individual silicon back gates and employing ferroelectric dielectrics with remnant polarization fields,the nonvolatile p–i–n homojunction with a clear gradient of Seebeck coefficient is electrically configured.Hot carriers in the graphene channel generated from the absorption of waveguide evanescent field are separated by the nonvolatile p–i–n homojunction effectively to yield considerable photocurrents.With zero-bias and zero-gate voltage,the nonvolatile graphene p–i–n homojunction photodetector integrated on the optical waveguide exhibits high and flat responsivity of 193 mAW^(−1)over the broadband wavelength range of 1560–1630 nm and an ultrafast dynamics bandwidth of 17 GHz measured in the limits of our instruments.With the high-performance on-chip photodetection,the nonvolatile graphene homojunction directly constructed on silicon photonic circuits promises the extended on-chip functions of the optoelectronic synapse,in-memory sensing and computing,and neuromorphic computing. 展开更多
关键词 nonvolatile graphene p i n homojunction silicon photonic crystal wavegui gate voltages chip photodetectors nonvolatile photodetector graphene p i n homojunction photothermoelectric effect separate photocarriersleading
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Ferroelectricity in biological building blocks:Slipping on a banana peel? 被引量:1
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作者 Syed A.M.Tofail 《Journal of Advanced Dielectrics》 2023年第4期60-64,共5页
Ferroelectricity in biological system has been anticipated both theoretically and experimentally over the past few decades.Claims of ferroelectricity in biological systems have given rise to confusion and methodologic... Ferroelectricity in biological system has been anticipated both theoretically and experimentally over the past few decades.Claims of ferroelectricity in biological systems have given rise to confusion and methodological controversy.Over the years,a“loop”of induced polarization in response to a varying applied electrical field and a consequent polarization reversal has prompted many researchers to claim ferroelectricity in biological structures and their building blocks.Other observers were skeptical about the methodology adopted in generating the data and questioned the validity of the claimed ferroelectricity as such,“loop”can also be obtained from linear capacitors.In a paper with somewhat tongue-in-cheek title,Jim Scott showed that ordinary banana peels could exhibit closed loops of electrical charge which closely resemble and thus could be misinterpreted as ferroelectric hysteresis loops in barium sodium niobate,BNN paraphrasing it as“banana”.In this paper,we critically review ferroelectricity in biological system and argue that knowing the molecular and crystalline structure of biological building blocks and experimenting on such building blocks may be the way forward in revealing the“true”nature of ferroelectricity in biological systems. 展开更多
关键词 FERROELECTRICITY PIEZOELECTRICITY PYROELECTRICITY biological materials ion channel voltage gating
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Major vacuolar TPC1 channel in stress signaling:what matters,K^(+),Ca^(2+) conductance or an ion‑flux independent mechanism?
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作者 Igor Pottosin Oxana Dobrovinskaya 《Stress Biology》 2022年第1期312-323,共12页
Two-pore cation channel,TPC1,is ubiquitous in the vacuolar membrane of terrestrial plants and mediates the long distance signaling upon biotic and abiotic stresses.It possesses a wide pore,which transports small mono-... Two-pore cation channel,TPC1,is ubiquitous in the vacuolar membrane of terrestrial plants and mediates the long distance signaling upon biotic and abiotic stresses.It possesses a wide pore,which transports small mono-and divalent cations.K^(+) is transported more than 10-fold faster than Ca^(2+) ,which binds with a higher affinity within the pore.Key pore residues,responsible for Ca^(2+) binding,have been recently identified.There is also a substantial pro-gress in the mechanistic and structural understanding of the plant TPC1 gating by membrane voltage and cytosolic and luminal Ca^(2+).Collectively,these gating factors at resting conditions strongly reduce the potentially lethal Ca^(2+) leak from the vacuole.Such tight control is impressive,bearing in mind high unitary conductance of the TPC1 and its abundance,with thousands of active channel copies per vacuole.But it remains a mystery how this high thresh-old is overcome upon signaling,and what type of signal is emitted by TPC1,whether it is Ca^(2+)or electrical one,or a transduction via protein conformational change,independent on ion conductance.Here we discuss non-exclusive scenarios for the TPC1 integration into Ca^(2+),ROS and electrical signaling. 展开更多
关键词 TPC1 POTASSIUM Calcium voltage gating Long-distance signaling VACUOLE
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Modeling the mechanics of calcium regulation in T lymphocyte:A finite element method approach
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作者 Parvaiz Ahmad Naik 《International Journal of Biomathematics》 SCIE 2020年第5期149-169,共21页
Changes in cellular Ca2+concentration control a variety of physiological activities including hormone and neurotransmitter release,muscular contraction,synaptic plas-ticity,ionic channel permeability,apoptosis,enzyme ... Changes in cellular Ca2+concentration control a variety of physiological activities including hormone and neurotransmitter release,muscular contraction,synaptic plas-ticity,ionic channel permeability,apoptosis,enzyme activity,gene transcription and reproduction process.Spatial-temporal Ca2+dynamics due to Ca2 t release,buffering and re-uptaking plays a central role in studying the Ca2+regulation in T lympho-cytes.In most cases,Ca2+has its major signaling function when it is elevated in the cytosolic compartment.In this paper,a two-dimensional mathematical model to study spatiotemporal variations of intracellular Ca2+concentration in T lymphocyte cell is proposed and investigated.The cell is assumed to be a circular shaped geomnetrical domain for the representation of properties of Ca2+dynamics within the cell includ-ing important parameters.Ca2+binding proteins for the dynamics of Ca2+are itself buffer and other physiological parameters located in Ca2+stores.The model incorpo-rates the important biophysical processes like difusion,reaction,voltage gated Ca2+channel,leak from endoplasmic reticulum(ER),efflux from cytosol to ER via sarco ER Ca2+adenosine triphosphate(SERCA)pumps,buffers and Na+/Ca2+exchanger.The proposed mathematical model is solved using a finite difference method and the finite element method.Appropriate initial and boundary conditions are incorporated in the model based on biophysical conditions of the problem.Computer simulations in MAT-LAB R2019b are employed to investigate mathematical models of reaction-diffusion equation.The effect of source,buffer,Nat/Ca2+exchanger,etc.on spatial and tempo-ral patterns of Ca2+in T lymphocyte has been studied with the help of numerical results.From the obtained results,it is observed that,the coordinated combination of the incor-porated parameters plays a significant role in Ca2+regulation in T lymphocytes.ER leak and voltage-gated Ca2+channel provides the necessary Ca2+to the cell when required for its proper functioning,while on the other side buffers,SERCA pump and Na+/Ca2+exchanger makes balance in the Ca2+concentration,so as to prevent the cell from death as higher concentration for longer time is harmful for the cell and can cause cell death. 展开更多
关键词 Nat/Ca2+exchanger SERCA purmp ER leak voltage gated Ca2+channel BUFFERS diffusion coefficient reaction-diffusion equations Ritz method and variational form
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