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Forensic Study on Objective Evaluation of Visual Acuity of Ametropia with the Event-related Potential P3
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作者 Fu-quan JIA Fang-liang LUO +3 位作者 Yan-he XIONG Long-long CHENG Zhi-qiang DANG Ji-hui LIU 《Current Medical Science》 SCIE CAS 2023年第3期609-614,共6页
Objective In this study,we aimed to assess the characteristics of the P3 component from an event-related potential(ERP)that was induced by visual acuity(VA)processing.Furthermore,we sought to provide electrophysiologi... Objective In this study,we aimed to assess the characteristics of the P3 component from an event-related potential(ERP)that was induced by visual acuity(VA)processing.Furthermore,we sought to provide electrophysiological evidence for the objective evaluation of VA.Methods We recruited 32 participants with myopia-related ametropia.They reported no other ocular diseases and had an uncorrected VA of 4.0 in both eyes.We used the block letter“E”at different visual angles and orientations as the graphic stimuli.The oddball paradigm,consisting of 4 modules,was used for ERP analysis.The standard stimuli of each module were identical,with a visual angle of 1°15′.The visual angles of the target stimuli were 1°15′,55′,24′,and 15′.The VA test was performed on each eye separately for all participants,and all characteristics of the P3 component were analyzed.Results There was no significant difference in the P3 peak letencies between the target stimulation angle 1°15′group and the 55′group,or between the target stimulation angle 24′group and the 15′group.There was a significant difference in the P3 peak letencies between the target stimulation angle 1°15′group and the 24′group as well as the 15′group.There was a significant difference in the P3 peak letencies between the target stimulation angle 55′group and the 24′group as well as the 15′group.No significant differences were observed in the P3 amplitude between modules.Conclusion In the oddball paradigm,P3 elicitation indicated a cognitive response to the target stimuli.These data showed that the characteristics of P3 can be used as an objective evaluation of VA. 展开更多
关键词 event-related potential p3 visual acuity forensic medicine AMpLITUDE
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The theoretical study on the potential energy curve for X^3△ state of TiO molecule 被引量:1
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作者 徐国亮 夏要争 +2 位作者 贾光瑞 刘玉芳 张现周 《Chinese Physics B》 SCIE EI CAS CSCD 2010年第9期309-312,共4页
This paper applies the density functional theory method to optimise the structure for X3A state of TiO molecule with the basis sets 6-31G, 6-31++G and 6-311G^**. Comparing the attained results with the experiments... This paper applies the density functional theory method to optimise the structure for X3A state of TiO molecule with the basis sets 6-31G, 6-31++G and 6-311G^**. Comparing the attained results with the experiments, it obtains the conclusion that the basis set 6-31++G is most suitable for the optimal structure calculations of X3A state of TiO molecule. The whole potential energy curve for the electronic state is further scanned by using B3P86/6-31++G method for the ground state, then it uses a least square fitted to Murrell-Sorbie functions, at last it calculates the spectroscopic constants and force constants, which are in better agreement with the experimental data. 展开更多
关键词 B3p86 TIO potential energy function spectroscopic constants
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Behavioral inhibition in female college students with schizotypal traits: An event-related potential study
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作者 Ji-Hyun Lee Myung-Sun Kim 《Open Journal of Psychiatry》 2012年第4期362-369,共8页
This study investigated behavioral inhibition in female college students with psychometrically defined schizotypal traits using a Go/NoGo task and event-related potentials (ERPs). The schizotypal-trait (n = 15) and no... This study investigated behavioral inhibition in female college students with psychometrically defined schizotypal traits using a Go/NoGo task and event-related potentials (ERPs). The schizotypal-trait (n = 15) and normal control (n = 15) groups were selected based on scores of the Schizotypal Personality Questionnaire (SPQ). The Go/NoGo task consisted of Go (requires response) and NoGo (requires no response) conditions. In terms of response time and accuracy rate for the Go/NoGo task, the two groups did not differ significantly. In terms of ERPs, the control group showed greater N2 amplitudes in response to NoGo (NoGo-N2) than to Go stimuli (Go-N2), whereas the schizotypal-trait group showed no significant difference in NoGo-N2 and Go-N2 amplitudes. In addition, the schizotypal-trait group showed reduced NoGo-N2 amplitudes at the frontal site compared to controls, and an association between SPQ scores and NoGo-N2 amplitudes measured at the frontal site. The two groups did not differ in P3 amplitudes. Since the N2 reflects the detection of response conflict and behavioral inhibition, the present results indicate that nonclinical individuals with schizotypal traits have difficulties in detecting response conflict and behavioral inhibition. 展开更多
关键词 BEHAVIORAL Inhibition EVENT-RELATED potentials Go/NoGo Task N2 p3 SCHIZOTYpAL TRAIT
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INFLUENCE OF ACUPUNCTURE ("JIN'S SAN ZHEN") ON BRAINSTEM EVOKED POTENTIALS IN MENTAL RETARDATION CHILDREN
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作者 袁青 马瑞玲 靳瑞 《World Journal of Acupuncture-Moxibustion》 2002年第3期8-12,共5页
Objective: To investigate the effect of acupuncture ("JIN’s San Zhen") on infantile mental retardation (MR). Methods: 44 cases of MR children were attributed to treatment group and 39 normal children to con... Objective: To investigate the effect of acupuncture ("JIN’s San Zhen") on infantile mental retardation (MR). Methods: 44 cases of MR children were attributed to treatment group and 39 normal children to control group. P 3 (event related potential) and brainstem evoked potentials were used as the indexes. Acupoints "Si shen Zhen", "Head Zhi San Zhen", "Hand Zhi San Zhen", "Foot Zhi San Zhen" were punctured with filiform needles, and stimulated by manipulating the needle once every 5 minutes with uniform reinforcing reducing method. The treatment was conducted once daily, 6 times every week, with 4 months being a therapeutic course. Results: In comparison with normal children, the latency of P 3 was longer and its amplitude lower in MR children. After 4 months’ acupuncture treatment, the latency was shortened and the amplitude increased significantly in comparison with pre treatment (P<0.01, 0.05). Results of the total intelligence quotient (TIQ) evaluation showed a 70.3% coincidence rate compared with improvement of P 3. Conclusion: Changes of P 3 and BAEP(brain auditory evoked potential) after acupuncture treatment may be related to the effect of "JIN’s San Zhen" in bettering clinical symptoms and signs of MR infantile patients. 展开更多
关键词 p3 BAEp 精神发育迟缓 针刺疗法
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任务负荷水平及输入通道形式对脑事件相关电位P3波的影响 被引量:2
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作者 董明清 马瑞山 《航天医学与医学工程》 CAS CSCD 1998年第4期277-281,共5页
为探讨任务负荷水平及输入通道形式对脑事件相关电位(ERP)P3波的影响,记录分析了18名男性青年受试者在完成6种负荷水平、附任务形式不同的双任务过程中ERP的P3波。双任务由手控追踪主任务(T)分别与Sternber... 为探讨任务负荷水平及输入通道形式对脑事件相关电位(ERP)P3波的影响,记录分析了18名男性青年受试者在完成6种负荷水平、附任务形式不同的双任务过程中ERP的P3波。双任务由手控追踪主任务(T)分别与Sternberg附任务(S)和Oddbal附任务(O)组成(即TS和TO),其难度由主任务目标运动的速度和维度控制。结果发现:主任务难度增加,P3波潜时(LAT)延长,波幅(AMP)则与附任务形式有关,主、附任务为视、听不同输入通道的TO双任务时AMP降低,主、附任务为视、视同一输入通道的TS双任务则AMP升高。提示任务负荷水平及输入通道形式对脑事件相关电位(ERP)P3波均有影响。 展开更多
关键词 脑力负荷 事件相关电位 航空航天工效 任务负荷
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XF_3(X=N,P,As)分子价层电离势的三阶代数图-表构建法计算
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作者 杨文艳 陈恒杰 《原子与分子物理学报》 CAS CSCD 北大核心 2014年第4期515-520,共6页
应用三阶代数图-表构建法(third-order algebraic diagrammatic construction scheme 简写为 ADC (3))计算了XF3(X=N,P,As)的价层垂直电离势(VIP).结果表明:内壳层电子关联对电离主峰位置影响非常小;来自不同理论结果的分子... 应用三阶代数图-表构建法(third-order algebraic diagrammatic construction scheme 简写为 ADC (3))计算了XF3(X=N,P,As)的价层垂直电离势(VIP).结果表明:内壳层电子关联对电离主峰位置影响非常小;来自不同理论结果的分子结构对电离主峰位置有较小影响;基组差异则表现的非常明显.由计算值和实验结果比较可知:在实验分子结构和 cc-pVDZ基组下,应用 ADC(3)得到的电离势与实验值整体上差距最小;ADC(3)计算的第一电离势往往小于实验值约0.4~0.8 eV,其余主峰位置与实验值差距约0.01~0.3 eV;随基组增大,ADC(3)结果与实验值偏差明显增大.因此,利用 ADC(3)方法计算价层电离势时,建议使用价层电子关联,基组则采用 cc-pVDZ或DZP,结构除采用实验外也可直接从耦合簇、密度泛函等理论获得. 展开更多
关键词 XF3 (X=N p As) 价层垂直电离势 三阶代数图-表构建法
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Influences on oxidation voltage and holding time on poly(3-methylthiophene) film for electrochromic stability
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作者 张波 徐晨 +3 位作者 徐国跃 刘初阳 卜红寒 张建超 《Chinese Physics B》 SCIE EI CAS CSCD 2018年第12期493-498,共6页
In this study, we report the influences of oxidation potential and holding time on the electrochromic(EC) stability of poly(3-methylthiophene)(P3MT) film during the electrochemical reaction. The cycle stability and tr... In this study, we report the influences of oxidation potential and holding time on the electrochromic(EC) stability of poly(3-methylthiophene)(P3MT) film during the electrochemical reaction. The cycle stability and transmittance changes of the film were investigated by optimizing the oxidation potential, and its chemical compositions were measured by x-ray photoelectron spectra after multiple electrochemical cycles. High oxidation potentials can increase the P3MT film color contrast and decrease its cycle stability because of accelerating chemical decomposition. Moreover, the holding time with potential pulsing was analyzed by using the optical memory of P3MT at an optimized oxidation potential, which revealed the reduced voltage duration saved energy consumption by 11.6% and improved the EC cycle stability without changing in color contrast. 展开更多
关键词 ELECTROCHROMISM p3MT oxidation potential cycle stability
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中国罕见A组轮状病毒DS-1样G3P[8]的全基因组分子特征分析
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作者 熊光萍 魏宇航 +6 位作者 彭蕊 范佳欣 唐晓苹 黄枝妙 董梦洁 车如意 李丹地 《中华实验和临床病毒学杂志》 CAS CSCD 2024年第1期29-36,共8页
目的对2021年采集于我国福建的A组轮状病毒(group A rotavirus,RVA)G3P[8]毒株FJ21351116进行全基因组分子特征分析。方法使用高灵敏度A组轮状病毒全基因组测序方法对FJ21351116进行全基因组测序。用MEGA11.0、Geneious9.0.2和DNASTAR... 目的对2021年采集于我国福建的A组轮状病毒(group A rotavirus,RVA)G3P[8]毒株FJ21351116进行全基因组分子特征分析。方法使用高灵敏度A组轮状病毒全基因组测序方法对FJ21351116进行全基因组测序。用MEGA11.0、Geneious9.0.2和DNASTAR软件通过核酸序列分析评估病毒的基因组特征。使用BioEdit v.7.0.9.0和PyMOL v.2.5.2分析VP7和VP4(VP8*)的中和表位。结果我国福建RVA毒株FJ21351116基因型为G3-P[8]-I2-R2-C2-M2-A2-N2-T2-E2-H2,系统进化分析显示,FJ21351116株的VP7、VP4、VP3、NSP2-NSP5基因与近几年日本检测到的马样DS-1样G3P[8]基因存在亲缘关系。而VP6、VP1、VP2、NSP1基因与大部分国家G2P[4]的相应基因亲缘关系近,特别是新加坡,表明该毒株是马样G3P[8]毒株与G2P[4]毒株共感染过程中通过基因重配形成的。FJ21351116的VP7/VP4基因与Rotarix和RotaTeq疫苗的进化分析表明,VP7和VP4(VP8*)中和抗原表位与疫苗氨基酸位点均存在多个突变。推测Rotarix和RotaTeq疫苗针对马样DS-1样G3P[8]RVA的保护效果不佳,且与Rotarix的中和抗原表位氨基酸差异高于RotaTeq。结论本研究发现一例中国罕见的DS-1样G3P[8]型RVA毒株,且疫苗株可能对其保护效果差,强调了持续监测RVA毒株及研发高效覆盖面全的RVA疫苗的重要性。 展开更多
关键词 A组轮状病毒 全基因组 DS-1-like G3p[8] 分子特征
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miR-429-3p mediates memory decline by targeting MKP-1 to reduce surface GluA1- containing AMPA receptors in a mouse model of Alzheimer’s disease
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作者 Man Luo Yayan Pang +10 位作者 Junjie Li Lilin Yi Bin Wu Qiuyun Tian Yan He Maoju Wang Lei Xia Guiqiong He Weihong Song Yehong Du Zhifang Dong 《Acta Pharmaceutica Sinica B》 SCIE CAS CSCD 2024年第2期635-652,共18页
Alzheimer ’s disease(AD) is a leading cause of dementia in the elderly.Mitogen-activated protein kinase phosphatase 1(MKP-1) plays a neuroprotective role in AD.However,the molecular mechanisms underlying the effects ... Alzheimer ’s disease(AD) is a leading cause of dementia in the elderly.Mitogen-activated protein kinase phosphatase 1(MKP-1) plays a neuroprotective role in AD.However,the molecular mechanisms underlying the effects of MKP-1 on AD have not been extensively studied.MicroRNAs(miRNAs) regulate gene expression at the post-transcriptional level,thereby repressing mRNA translation.Here,we reported that the microRNA-429-3p(miR-429-3p) was significantly increased in the brain of APP23/PS45 AD model mice and N2AAPPAD model cells.We further found that miR-429-3p could downregulate MKP-1 expression by directly binding to its 3’-untranslated region(3’ UTR).Inhibition of miR-429-3p by its antagomir(A-miR-429) restored the expression of MKP-1 to a control level and consequently reduced the amyloidogenic processing of APP and Aβ accumulation.More importantly,intranasal administration of A-miR-429 successfully ameliorated the deficits of hippocampal CA1 long-term potentiation and spatial learning and memory in AD model mice by suppressing extracellular signal-regulated kinase(ERK1/2)-mediated GluAl hyperphosphorylation at Ser831 site,thereby increasing the surface expression of GluAl-containing α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors(AMPARs).Together,these results demonstrate that inhibiting miR-429-3p to upregulate MKP-1 effectively improves cognitive and synaptic functions in AD model mice,suggesting that miR-429/MKP-1 pathway may be a novel therapeutic target for AD treatment. 展开更多
关键词 Alzheimer's disease MKp-1 miR-429-3p AMpAreceptor Learning and memory Long-term potentiation
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Nerve growth factor in muscle afferent neurons of peripheral artery disease and autonomic function 被引量:1
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作者 Lu Qin Jianhua Li 《Neural Regeneration Research》 SCIE CAS CSCD 2021年第4期694-699,共6页
In peripheral artery disease patients,the blood supply directed to the lower limbs is reduced.This results in severe limb ischemia and thereby enhances pain sensitivity in lower limbs.The painful perception is induced... In peripheral artery disease patients,the blood supply directed to the lower limbs is reduced.This results in severe limb ischemia and thereby enhances pain sensitivity in lower limbs.The painful perception is induced and exaggerate during walking,and is relieved by rest.This symptom is termed by intermittent claudication.The limb ischemia also amplifies autonomic responses during exercise.In the process of pain and autonomic responses originating exercising muscle,a number of receptors in afferent nerves sense ischemic changes and send signals to the central nervous system leading to autonomic responses.This review integrates recent study results in terms of perspectives including how nerve growth factor affects muscle sensory nerve receptors in peripheral artery disease and thereby alters responses of sympathetic nerve activity and blood pressure to active muscle.For the sensory nerve receptors,we emphasize the role played by transient receptor potential vanilloid type 1,purinergic P2X purinoceptor 3 and acid sensing ion channel subtype 3 in amplified sympathetic nerve activity responses in peripheral artery disease. 展开更多
关键词 acid sensing ion channel subtype 3 exercise pressor reflex muscle afferents nerve growth factor p2X purinoceptor 3 peripheral artery disease transient receptor potential vanilloid type 1
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Energy <i>β</i>-Conformal Change and Special Finsler Spaces
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作者 Amr Soleiman Amira A. Ishan 《Journal of Modern Physics》 2013年第7期983-990,共8页
The main aim of the present paper is to establish an intrinsic investigation of the energy β-conformal change of the most important special Finsler spaces, namely, Ch-recurrent, Cv-recurrent, C0-recurrent, Sv-recurre... The main aim of the present paper is to establish an intrinsic investigation of the energy β-conformal change of the most important special Finsler spaces, namely, Ch-recurrent, Cv-recurrent, C0-recurrent, Sv-recurrent, quasi-C-reducible, semi-C-reducible, C-reducible, P-reducible, C2-like, S3-like, P2-like and h-isotropic, ···, etc. Necessary and sufficient conditions for such special Finsler manifolds to be invariant under an energy β-conformal change are obtained. It should be pointed out that the present work is formulated in a prospective modern coordinate-free form. 展开更多
关键词 Energy β-Conformal CHANGE Ch-Recurrent Cv-Recurrent C0-Recurrent C2-like Quasi-C-Reducible C-Reducible Berwald Space Sv-Recurrent S3-like p2-like h-Isotropic
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环境因子及藻体密度对条斑紫菜生长与氮磷去除效率的影响 被引量:8
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作者 邵飞 费岚 +4 位作者 吴海龙 张建恒 胡明 韦章良 何培民 《生态学报》 CAS CSCD 北大核心 2014年第21期6164-6171,共8页
以条斑紫菜为材料,系统探究实验室条件下光照强度、温度、光周期、盐度和干出等生态因子和藻体密度对条斑紫菜生长和氮磷去除的影响,为今后条斑紫菜大规模栽培的生态修复潜力研究及海洋富营养化治理奠定理论基础。实验室条件下不同藻体... 以条斑紫菜为材料,系统探究实验室条件下光照强度、温度、光周期、盐度和干出等生态因子和藻体密度对条斑紫菜生长和氮磷去除的影响,为今后条斑紫菜大规模栽培的生态修复潜力研究及海洋富营养化治理奠定理论基础。实验室条件下不同藻体密度、光照强度、光周期、温度、盐度和干出时间对条斑紫菜生长及氮磷去除效率的影响。结果表明:条斑紫菜在藻体密度0.1 g/L、光照强度为120μmol m-2s-1时特定生长率最大,为38.1%。随着藻体密度增加,光照强度减小,其特定生长率逐渐减小,当藻体密度为1.6 g/L、光照强度为30μmol m-2s-1时,特定生长率最小为12.6%;藻体密度0.1—0.8 g/L时随着藻体密度的增加条斑紫菜对NO-3-N和PO3-4-P的去除效率显著增加,藻体密度为0.8—1.6 g/L时藻体对NO-3-N和PO3-4-P去除效率差异不大,其中藻体密度1.6 g/L、光照强度90μmol m-2s-1时条斑紫菜对NO-3-N和PO3-4-P去除效率均达到93%以上。为进一步探究其他环境因子的影响,因此在温度和光周期实验中选择氮磷去除率适中的藻体密度0.4 g/L和最适光照强度90μmol m-2s-1。温度为15℃、光周期为16L∶8D条件下条斑紫菜特定生长率最大,为36.9%,且氮和磷去除效率也最大,分别为91.9%和81.6%。条斑紫菜生长适宜盐度为10—35,最佳盐度为25,干出时间越长生长越慢,氮磷去效率也越低,且有较大交互作用,但干出后的紫菜光合作用更强。以上研究将为应用大型海藻条斑紫菜大规模栽培进行生态修复奠定基础。 展开更多
关键词 条斑紫菜 生态修复潜力 特定生长率 氮磷吸收率
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轻、中度缺氧对事件相关电位的影响及不同刺激模式的比较 被引量:4
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作者 程宏伟 马瑞山 +1 位作者 倪鹤鹦 王兴邦 《航天医学与医学工程》 CAS CSCD 1999年第1期23-25,共3页
目的观察轻、中度缺氧对脑事件相关电位(ERP)的影响,比较不同刺激模式诱发的ERP对缺氧的敏感性。方法12名受试者在地面、2500m和4300m模拟高度(吸入低氧混合气)分别进行视觉Oddbal、Sternberg记... 目的观察轻、中度缺氧对脑事件相关电位(ERP)的影响,比较不同刺激模式诱发的ERP对缺氧的敏感性。方法12名受试者在地面、2500m和4300m模拟高度(吸入低氧混合气)分别进行视觉Oddbal、Sternberg记忆量(MSET)为1和MSET为3的任务测试,记录ERP的P3潜伏期、波幅和反应时(RT)及反应错误率(ER)。结果4300m高度缺氧时P3潜伏期显著延长,任务难度较大时(Sternberg模式MSET=3)ER增高;2500m高度缺氧时各指标无明显改变;以Sternberg模式MSET=1诱发的ERP波形清晰,缺氧时P3潜伏期延长显著。结论4300m高度缺氧对ERP有明显影响,P3潜伏期是评定缺氧时脑认知能力降低的敏感指标。Sternberg模式MSET=1诱发的ERP对缺氧敏感,是一种较为理想的刺激模式。 展开更多
关键词 缺氧 血氧饱和度 事件相关电位 刺激模式 RT
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单纯疱疹性脑炎事件相关电位研究 被引量:1
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作者 余茜 雷晴 +1 位作者 李晓红 叶世金 《泸州医学院学报》 2001年第3期180-182,共3页
目的 :探讨单纯疱疹病毒性脑炎 (HSE)事件相关电位。方法 :对诊断明确HSE 2 6例患者进行 2次事件相关电位 (ERP)检测 (入院与出院 )。结果 :HSE患者P3 潜伏期均延迟 ,波形不整或波幅降低为主要改变。颞叶或全脑病变者 ,其P3 潜伏期明显... 目的 :探讨单纯疱疹病毒性脑炎 (HSE)事件相关电位。方法 :对诊断明确HSE 2 6例患者进行 2次事件相关电位 (ERP)检测 (入院与出院 )。结果 :HSE患者P3 潜伏期均延迟 ,波形不整或波幅降低为主要改变。颞叶或全脑病变者 ,其P3 潜伏期明显延迟 (P <0 0 1) ,经治疗后其潜伏期无明显改善。结论 展开更多
关键词 单纯疱疹病毒性脑炎 事件相关电位 全脑弥散性损害 p3潜伏期 p3波幅
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Theoretical studies of the reactions of O(~3p) with halogenated methyl (Ⅰ)——Reaction mechanism of the O(~3p) + CH_2Cl reaction
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作者 侯华 王宝山 顾月姝 《Science China Chemistry》 SCIE EI CAS 1999年第5期479-484,共6页
The reaction of O(<sup>3</sup>P) with CH<sub>2</sub>Cl radical has been studied using ab initio molecular orbital theory. G2 (MP2) method is used to calculate the geometrical parameters, vi... The reaction of O(<sup>3</sup>P) with CH<sub>2</sub>Cl radical has been studied using ab initio molecular orbital theory. G2 (MP2) method is used to calculate the geometrical parameters, vibrational frequencies and energies of various stationary points on the potential energy surface. The reaction mechanism is revealed. The addition of O(<sup>3</sup>P) with CH<sub>2</sub>Cl leads to the formation of an energy rich intermediate OCH<sub>2</sub>Cl which can subsequently undergo decomposition or isomerization to the final products. The calculated heat of reaction for each channel is in agreement with the experimental value. The production of H+CHClO and Cl+CH<sub>2</sub>O are predicted to be the major channels. The overall rate constants are calculated using transition state theory on the basis of ab initio data. The rate constant is pressure independent and exhibits negative temperature dependence at lower temperatures, in accordance with the experimental results. 展开更多
关键词 ab INITIO potential energy surface o(3p) atom CH2CI radical.
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Examining Electrostatic Influences on Base-Flipping:A Comparison of TIP3P and GB Solvent Models
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作者 Allyn R.Brice Brian N.Dominy 《Communications in Computational Physics》 SCIE 2013年第1期223-237,共15页
Recently,it was demonstrated that implicit solvent models were capable of generating stable B-form DNA structures.Specifically,generalized Born(GB)implicit solvent models have improved regarding the solvation of confo... Recently,it was demonstrated that implicit solvent models were capable of generating stable B-form DNA structures.Specifically,generalized Born(GB)implicit solvent models have improved regarding the solvation of conformational sampling of DNA[1,2].Here,we examine the performance of the GBSW and GBMV models in CHARMM for characterizing base flipping free energy profiles of undamaged and damaged DNA bases.Umbrella sampling of the base flipping process was performed for the bases cytosine,uracil and xanthine.The umbrella sampling simulations were carried-out with both explicit(TIP3P)and implicit(GB)solvent in order to establish the impact of the solvent model on base flipping.Overall,base flipping potential of mean force(PMF)profiles generated with GB solvent resulted in a greater free energy difference of flipping than profiles generated with TIP3P.One of the significant differences between implicit and explicit solvent models is the approximation of solute-solvent interactions in implicit solvent models.We calculated electrostatic interaction energies between explicit water molecules and the base targeted for flipping.These interaction energies were calculated over the base flipping reaction coordinate to illustrate the stabilizing effect of the explicit water molecules on the flipped-out state.It is known that nucleic base pair hydrogen bonds also influenced the free energy of flipping since these favorable interactions must be broken in order for a base to flip-out of the helix.The Watson-Crick base pair hydrogen bond fractions were calculated over the umbrella sampling simulation windows in order to determine the effect of base pair interactions on the base flipping free energy.It is shown that interaction energies between the flipping base and explicit water molecules are responsible for the lower base flipping free energy difference in the explicit solvent PMF profiles. 展开更多
关键词 TIp3p generalized Born FLIppING implicit solvation potential of mean force DNA DNA damage
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表面等离子体无掩膜干涉光刻系统的数值分析(英文) 被引量:5
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作者 董启明 郭小伟 《光子学报》 EI CAS CSCD 北大核心 2012年第5期558-564,共7页
表面等离子体激元具有近场增强效应,可以代替光子作为曝光源形成纳米级特征尺寸的图像.本文数值分析了棱镜辅助表面等离子体干涉系统的参量空间,并给出了计算原理和方法.结果表明,适当地选择高折射率棱镜、低银层厚度、入射波长和光刻... 表面等离子体激元具有近场增强效应,可以代替光子作为曝光源形成纳米级特征尺寸的图像.本文数值分析了棱镜辅助表面等离子体干涉系统的参量空间,并给出了计算原理和方法.结果表明,适当地选择高折射率棱镜、低银层厚度、入射波长和光刻胶折射率,可以获得高曝光度、高对比度的干涉图像.入射波长为431nm时,选择40nm厚的银层,曝光深度可达200nm,条纹周期为110nm.数值分析结果为实验的安排提供了理论支持. 展开更多
关键词 干涉光刻 表面等离子体激元 克莱舒曼结构
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下体负压晕厥前症状下事件相关电位变化特征 被引量:10
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作者 陈勇胜 王致洁 +1 位作者 焦志刚 颜桂定 《中华航空航天医学杂志》 CSCD 1998年第4期220-222,共3页
目的探讨下体负压晕厥前症状(PSS)下事件相关电位(ERPs)的P3潜时(P3L)变化特征,为飞行员加速度性晕厥的医学鉴定提供实验方法和依据。方法用下体负压方法(LBNP)诱发PSS,观察ERPs的P3L变化特征。结... 目的探讨下体负压晕厥前症状(PSS)下事件相关电位(ERPs)的P3潜时(P3L)变化特征,为飞行员加速度性晕厥的医学鉴定提供实验方法和依据。方法用下体负压方法(LBNP)诱发PSS,观察ERPs的P3L变化特征。结果出现PSS时,ERPs的P3L由343.35±14.72ms延长至506.87±37.44ms(F(6,48)=14.96,P<0.05,OZ电极),相关任务反应时(RT)由508.65±11.13ms延长至631.25±29.16ms(t=2.97,P<0.05),靶刺激反应错误率由(4.00±1.67)%增加至(43.38±3.54)%(t=3.06,P<0.05)。PSS后第5min,P3L仍明显高于基线值(P<0.05)。而RT、错误率与基线值已无显著差异(P>0.05)。结论ERPs的P3L结合RT、错误率等指标对飞行员加速度性晕厥的研究有潜在应用价值。 展开更多
关键词 下体负压 事件相关电位 p3潜时 晕厥前症状
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