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细叶菊挥发油的化学成分的研究安承熙(青海省测试计算中心,西宁810008)STUDIESONTHECHEMICALCONSTITUENTSOFESSENTIALOILSOFAJANIATANUIFOLIAAnChengxi(QinghaiProvi... 相似文献
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石灰性土壤上植物根际中Fe,Mn的形态分布及其与植物吸收的关系 总被引:2,自引:1,他引:1
研究了石灰性土壤上5种作物品种根际微生态环境中Fe、Mn的形态分布.结果表明,交换态Fe(EX-Fe)、碳酸盐结合态Fe(CARB-Fe)、无定形氧化铁(AO-Fe)和交换态Mn(E-Mn)、碳酸盐结合态Mn(CARB-Mn)在根际土壤中都呈现明显的累积.各品种根际中的累积量有较大差异.相关分析表明,黄潮土上植株含Fe量、吸Fe量与根际土壤AO-Fe含量呈显著正相关.根际有效态Fe累积不仅是根际pH作用的结果,与根系分泌物对难溶性Fe活化有关.根际有效态Mn累积则受到根际土壤Eh的影响. 相似文献
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血管内皮细胞生长因子受体Flt—1胞外区基因的克隆及其在中国仓?… 总被引:1,自引:0,他引:1
朋原代培养的人脐静脉血管内皮细胞(HUVEC)提取细胞总RNA,采用逆转录PCR(RT-PCR)方法得到VEGF受体Flt-1胞外区前3个IgG样区域cDNA片段(Flt-1n3)。将获得的受体基因克隆到真核表达载体pcD-NA3.1中,得到重组质粒pcDNA3.1/Flt-1n3,通过南体转染方法将其转入中国仓鼠卵巢细胞(CHO),用G418筛选得到稳定表达目的蛋白的细胞砍隆。经固相结合实验筛选 相似文献
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植物性细胞人工融合的研究进展周嫦(武汉大学生命科学学院,武汉430072)ADVANCESINRESEARCHONFUSIONOFPLANTREPRODUCTIVECELLS¥ZhouChang(DepartmentofBtology,WuhanUn... 相似文献
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铜对马铃薯块茎产量与生理生化特性的影响白嵩吕芳芝*白宝璋李秀坤刘志清**陈文荣(吉林农业大学,长春130118)EFFECTSOFCOPPERONTUBERYIELDANDPHYSIO┐LOGICALANDBIOCHEMICALCHARAC┐TER... 相似文献
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茉莉酸类物质与脱落酸生理作用的比较研究 总被引:9,自引:1,他引:8
茉莉酸类物质与脱落酸生理作用的比较研究江月玲郑燕玲(广州师范学院生物系,广州510400)潘瑞炽(华南师范大学生物系,广州510631)COMPARATIVESTUDYOFPHYSIOLOGICALEFFECTSOFABA,JASMONICACID... 相似文献
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水稻根系生长生理的研究进展 总被引:37,自引:0,他引:37
水稻根系生长生理的研究进展潘晓华(江西农业大学,南昌330045)王永锐傅家瑞(中山大学,广州510275)DVANCEINTHESTUDYONTHEGROWTH┐PHYSIOLOGYINRICEOFROOTSYSTEM(ORYZASATIVA)Pa... 相似文献
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小麦不同类型愈伤组织及其悬浮系的原生质体培养和植株再生 总被引:1,自引:0,他引:1
小麦不同类型愈伤组织及其悬浮系的原生质体培养和植株再生侯丙凯陈际江(山东大学生物系,济南250100)宋协志(莱阳农学院,莱阳265200)PLANTREGENERATIONFROMPROTOPLASTSOFDIFFERENTTYPESOFWHEA... 相似文献
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Modally specific and supramodal components of EEG dynamics, related to involuntary reorientation of anticipatory attention from internal into external, were studied using unblocking of either visual or acoustic apparatus. EEG registration took place while the examinees were in the resting states: with opened eyes; with closed eyes; with closed eyes and inserted noise-protective earplugs. Averaged values of EEG power in each of the derivations and of EEG coherence in each of the derivation pairs were calculated for an every examinee and for each of the states. The estimations were done in delta, theta, alphal, alpha2, beta1, beta2, gamma frequency bands. The received results support an idea about manifestation of both supramodal and modally specific components in brain mechanisms of involuntary anticipatory attention. These results seem to be of certain interest for existing discussion on divergence and convergence between systemic mechanisms of visual and auditory attention. 相似文献
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Transition from a resting state with eyes closed (REC) to a resting state with eyes open (REO) is associated with visible changes in EEG, which are traditionally considered to be a sign of reorganization of the brain’s activity in response to visual stimuli. The EEGs recorded in the REC and REO states in complete darkness, when the stimulatory effect of light to the eye’s retina was absent, were compared. Thirty healthy subjects participated in the study. EEG in the range of 1.5–50 Hz was recorded from nineteen zones of the head monopolarly. It was found that, under conditions of complete darkness, the REC and REO states significantly differed in their EEG spectral power and coherence in the Δ, θ, α1, α2, β1, β2 and γ frequency bands. Under experimental conditions, these changes in the EEG could not be induced by external influence to the visual system. Therefore, we suppose that they are correlates of the switching of involuntary preliminary attention from internally directed attention specific for the REC state to externally directed attention specific for the REO state. 相似文献
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Objective
To investigate the potentially prognostic value of a resting state electroencephalogram (EEG) with regards to the clinical outcome from vegetative and minimally conscious states (VS and MCS) in terms of survival six months after a brain injury.Methods
We quantified a dynamic repertoire of EEG oscillations in resting condition with eyes closed in patients in VS and MCS. The exact composition of EEG oscillations was assessed by analysing the probability-classification of short-term EEG spectral patterns.Results
Results demonstrated that (a) the diversity and the variability of EEG for Non-Survivors were significantly lower than for Survivors; and (b) a higher probability of mostly delta and slow-theta oscillations occurring either alone or in combination were found during the first assessment for patients with a bad outcome (i.e., those who died) within six months of an injury compared to patients who survived. At the same time, patients with a good outcome (i.e., those who survived) after six months post-injury had a higher probability of mostly fast-theta and alpha oscillations occurring either alone or in combination during the first assessment when compared to patients who died within six months of an injury.Conclusions
Resting state EEGs properly analysed may have a potentially prognostic value with regards to the outcome from VS or MCS in terms of survival six months after a brain injury.Significance
This work may have implications for clinical care, rehabilitative programmes and medical–legal decisions for patients with impaired consciousness states after being in a coma due to acute brain injuries. 相似文献16.
Getmanenko OV Belov DR Kanunikov IE Smit NIu Sibarov DA 《Rossi?skii fiziologicheski? zhurnal imeni I.M. Sechenova / Rossi?skaia akademiia nauk》2006,92(8):930-948
Investigation was fulfilled on healthy subjects (22) and on outpatients (62). The EEG by the standard scheme as recorded at resting with open and closed eyes and under different functional loads. These records were processed in accordance with the EEC phase structure with the aid of computer animation technology. The main idea of the phase structure technology consists in rejection of one supporting lead. Time shifts were measured only between two neighbouring electrodes, so that the oscillations under comparison were always highly coherent. Time errors were evaluated according to crosscorrelation function maximum shift. The differences between high- and low-frequency EEG rhythms were shown to be only quantitative from the phase structure viewpoint. Qualitatively, the rhythm properties were equal and came to slow (second) phase structure oscillations. Low frequency activity compared to high frequency one was characterized by greater phase shifts from electrode to electrode. Phase shifts of potentials are forming the structure which, as a whole, is very similar in different people and is reproduced in different states. Initial EEG waves appearance is statistical linked with main sensory projections: visual (occiput), auditory (temples) and somatic (parietal region) with addition of frontal region. Redistribution of phase leadership in favor of occipital pole and to both temporal regions when eyes are open is described. It is apparently dependent on the sensory surge level from thalamus to a given cortex region. Phase gradient direction seems to reflect the cortex current density gradient which is parallel to surface. It can be used for localization of compact sources lying near to cortex. 相似文献
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S. G. Danko N. P. Bechtereva L. M. Kachalova N. V. Shemyakina M. G. Startchenko 《Human physiology》2005,31(6):623-629
Spatial EEG synchronization was studied using mean EEG coherences in 57 subjects in a resting state with the eyes open, during memorization of verbal bilingual semantic pairs (Latin and Russian), and during retrieval (monitoring) of the learned information. Statistical comparison of the EEG spectral power in the frequency bands θ, α 1, α2, β1, β2, and γ showed that induction of the states of memorization and retrieval of the verbal information resulted in multiple significant increases in the mean coherence (spatial synchronization) as compared to the state of rest. These increases were significantly higher in the state of retrieval than in the state of memorization. Such changes simultaneously occurred in different frequency bands and over the entire cortex. The highest relative augmentations of coherence with the highest significance estimates were observed in long-distance derivation pairs involving the temporal areas or combining the anterofrontal and frontal derivations with the parietal and occipital ones. The results are discussed in combination with data obtained in the same study for changes in EEG local synchronization and reported earlier. The intense rearrangements of the bioelectrical activity of the cortex may be determined both by the effect of cognitively specific mechanisms of encoding-decoding of information in the memory system and by a cognitively nonspecific modulating system of the brain. 相似文献
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We recorded EEG from both hemispheres and documented the state of the two eyes in two species of Cetaceans (one beluga and one bottlenose dolphin) and one species of Pinnipeds (two northern fur seals). In the dolphin and beluga we found that episodes of unihemispheric slow wave sleep (USWS) were associated with asymmetry in eye state. During USWS and asymmetrical SWS the eye contralateral to the sleeping hemisphere was mostly closed or in an intermediate state while the eye contralateral to the waking hemisphere was more often open or in an intermediate state. Bilateral eye opening indicated waking in about 80% cases and unilateral eye closure indicated USWS with an accuracy of about 75%. Bilateral eye closure was rare (< 2% of the observation time) and was not necessarily associated with high amplitude SWS. In fur seals, episodes of one eye briefly opening usually occurred in the beginning of sleep episodes and lasted several minutes. Those episodes were frequently associated with lower amplitude EEG slow waves in the contralateral brain hemisphere. During most of their sleep on land, fur seals had both eyes tightly closed. No EEG asymmetry was recorded at this time. Although eye state and EEG stage are correlated in the bottlenose dolphin, beluga and fur seals, short episodes of EEG synchrony (less then 1 min) occur contralateral to an open eye and waking (a more activated EEG) activity can be present contralateral to a closed eye. The available data suggest that two functions of USWS/EEG asymmetry during SWS in Cetaceans and fur seals are multisensory control of the environment and maintenance of motion and postures of sleep. The adaptive advantages of USWS throughout the evolution of Cetaceans and Pinnipeds from terrestrial mammals to present forms could include 1) the avoidance of predators and maintenance of contact with other animals of the same species; 2) continuance of regular breathing; 3) and effective thermoregulation in the water environment. 相似文献
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Quantitative statistical estimates of changes in ultraslow phasic electrical activity of the brain (in the range 0.05–0.5 Hz) and the EEG (1.5–50 Hz) with time were compared in the basic (reference) states of quiet wakefulness with the eyes open and closed (EO and EC, respectively). In both states, the changes in the power and coherence of ultraslow phasic activity and the EEG had similar trends; however, the topographic patterns of the changes were different. The obtained data confirm the assumption on different structural and functional bases of the EEG and ultraslow phasic activity of the brain and indicate polysystemic differences between the EO and EC states. 相似文献
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M V Bodunov 《Zhurnal vysshe? nervno? deiatelnosti imeni I P Pavlova》1985,35(6):1045-1052
EEG monopolarly recorded in points F3, F4, O1, O2 of 20 healthy subjects in six states (quiet wakefulness with open or closed eyes, spontaneous button pressings in arbitrary moments of time, listening to clicks, reaction to clicks by pressing the button at random or at equal intervals between stimuli), were processed by means of the computer program transforming the raw EEG tracings to a sequence of stationary segments. The accumulated segments were divided into classes of "similar" ones by a two-stage procedure of cluster analysis. In each lead six types of segments were identified forming populations of structural units of an individual human EEG. Four types were recorded all over the brain: their spectra were of a great resemblance in different brain areas. The EEG of each individual was characterized by a certain combination of segment types which practically did not change by their quality in different states of the subject. 相似文献