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41.
This paper reviews recent topics of clinical application of functional electrical stimulation (FES) for the paralyzed extremities in Japan. Transcutaneous and percutaneous FES systems have been clinically used in Japan. Candidates of extremity FES arer mostly stroke and spinal cord injury patients. By using percutaneous FES system, all of the joints of the upper extremity including the shoulder have been controlled for activities of daily living in the hemiplegic patient. Simultaneous FES control of the hand and wrist and the bilateral hands have also been achieved in C5 and C6 quadriplegics, respectively. Hybrid FES systems using percutaneous and surface electrodes, where FES is used in combination with orthoses, have been applied to the paraplegics because they are highly practical for assisting their locomotive activities. Percutaneous FES have been also provided the amyotropic lateral sclerosis patients with standing up motion. A total implant FES system with 16 output channels is currently developing as a next generation FES system.  相似文献   
42.
Historically, conventional solar cells were built from inorganic materials such as silicon. Although the efficiency of such conventional solar cells is high, very expensive materials and energy intensive processing techniques are required.Hybrid and photoelectrochemical (dye sensitized) solar cells have been the cheap alternatives for conventional silicon solar cells. A hybrid solar cell consists of a combination of both organic and inorganic materials therefore, combines the unique properties of inorganic semiconductors with the film forming properties of the conjugated polymers. Organic materials are inexpensive, easily processable and their functionality can be tailored by molecular design and chemical synthesis. On the other hand, inorganic semiconductors can be manufactured as nanoparticles and inorganic semiconductor nanoparticles offer the advantage of having high absorption coefficients and size tunability. By varying the size of the nanoparticles the bandgap can be tuned therefore the absorption range can be tailored.In this short review, we will focus on the concepts of organic/inorganic “hybrid” solar cells.  相似文献   
43.
刘林  李淑兰 《植物学通报》2003,20(5):585-588
用透射电子显微镜观察了非洲狼尾草珠心组织中细胞核穿壁运动。一个细胞核向相邻细胞转移时,可以进入一个或多个孔道:孔道直径0.33~0.68μm。处于穿壁状态的细胞核染色质不正常地浓缩,电子密度大。  相似文献   
44.
Redox processes consisting of disproportionation and syn-proportionation are reviewed with special attention to metal complexes containing carbon-based ligands, i.e. carbon monoxide or unsaturated hydrocarbons. An introduction and a survey of reactions aimed to show the large applicability of syn-proportionation reactions in the field of coordination chemistry, is followed by examples of the use of these redox processes for the preparation of catalytic precursors. The latter studies derive from the idea that if a syn-proportionation reaction can be carried out between two complexes containing different metals in different oxidation states, inter-metallic systems could be formed which may act as active catalysts, e.g. for polymerization reactions.  相似文献   
45.
Plant family 1 UDP-dependent glycosyltransferases (UGTs) catalyze the glycosylation of a plethora of bioactive natural products. In Arabidopsis thaliana, 120 UGT encoding genes have been identified. The crystal-based 3D structures of four plant UGTs have recently been published. Despite low sequence conservation, the UGTs show a highly conserved secondary and tertiary structure. The sugar acceptor and sugar donor substrates of UGTs are accommodated in the cleft formed between the N- and C-terminal domains. Several regions of the primary sequence contribute to the formation of the substrate binding pocket including structurally conserved domains as well as loop regions differing both with respect to their amino acid sequence and sequence length. In this review we provide a detailed analysis of the available plant UGT crystal structures to reveal structural features determining substrate specificity. The high 3D structural conservation of the plant UGTs render homology modeling an attractive tool for structure elucidation. The accuracy and utility of UGT structures obtained by homology modeling are discussed and quantitative assessments of model quality are performed by modeling of a plant UGT for which the 3D crystal structure is known. We conclude that homology modeling offers a high degree of accuracy. Shortcomings in homology modeling are also apparent with modeling of loop regions remaining as a particularly difficult task.  相似文献   
46.
The use of vibrational spectroscopic methods to elucidate the states present in metal complexes of dipyrido[3,2-a:2,3-c]phenazine (dppz) are reviewed. The presence of the close lying b1(ψ) and b1(phz) molecular orbitals leads to a number of close lying intraligand and MLCT excited states. Using resonance Raman spectroscopy the nature of initial photoexcitation may be established as M→b1(ψ). For Ru(II) complexes the lowest excited state is 3MLCT(phz) in nature. However, for [Re(CO)3Cl] complexes the relaxation from the initial excited state may lead to population of a 3MLCT(phen), 3MLCT(phz) state, an state, or an equilibrium between these states. Time-resolved resonance Raman spectroscopy may be used to identify the presence of dppz·- or the state and has also been used to identify features associated with intercalation of dppz complexes with DNA. The Raman methods are less effective at detecting the short time dynamics between these states. However, this may be accomplished using time-resolved infrared spectroscopy in which all three states may be unambiguously determined. The clearest picture of the dynamics in dppz complexes has been achieved by using a combination of time-resolved resonance Raman, time-resolved infrared and DFT calculations for rhenium(I) complexes.  相似文献   
47.
真菌诱导子对青蒿发根细胞生长和青蒿素积累的影响   总被引:8,自引:0,他引:8  
3种真菌诱导子(大菌丽花轮枝孢(Verticillium dahiae Kleb.)、葡枝根霉(Rhizopus stolonifer(Ehrenb.exFr.)Vuill)和束状刺盘孢(Colletorichum dematium(Pers.)Grove)处理青蒿(Artemisia annuaL.)的发根,均能促进发根中青蒿素的积累,其中以大丽花轮枝孢的诱导效果最好;对细胞生长均没有明显影响,  相似文献   
48.
蜜环菌诱导子对丹参冠瘿组织积累丹参酮的影响   总被引:2,自引:0,他引:2  
以 6 7_V液体培养基为基本培养基 ,利用计算机软件“均匀设计、回归分析及优化系统” ,研究了蜜环菌(ArmillariamelleaKarst)诱导子浓度、诱导子的加入时间与处理的收获时间对丹参 (SalviamiltiorrhizaBunge)冠瘿组织积累丹参酮的影响。结果表明 ,蜜环菌诱导子浓度为 119mL/L、第 0天加入诱导子、第 2 9天收获培养物与培养液时可获得最高的丹参酮生产量 (147mg/L ,P <0 .0 5 ) ,蜜环菌诱导子浓度为 113mL/L、第 0天加入诱导子、第 2 6天收获培养液时可获得最高的丹参酮生产量 (6 2mg/L ,P <0 .0 5 ) ,蜜环菌诱导子浓度为 87mL/L、第 0天加入诱导子、第2 8天收获培养物时可获得最高的丹参酮生产量 (94mg/L ,P <0 .0 5 )。结果证实 ,计算机软件“均匀设计、回归分析及优化系统”对于观察值受多因素影响的研究非常有效和方便。  相似文献   
49.
中国辽宁省始新世水杉的研究   总被引:4,自引:0,他引:4  
以辽宁省抚顺早始新世古城子组和计军屯组的水杉(Metasequoia Miki)为研究对象,对其雌球果、雄球花枝和营养枝叶的形态、叶表皮和雄球花苞片表皮的结构进行了研究分析,并与M.glyptostroboides,M.occidentalis,M.milleri的性状进行比较,认定其属于M.occidentalis。并没得M.glyptostroboides和抚顺水杉叶下表皮气孔分布区内的平均气  相似文献   
50.
从石竹科植物多荚草(Polycarpon prostratum(Forssk.)Aschers.et Schwein.ex Aschers)中分离得到3个新的柴胡皂甙类化合物:prostratoside A ̄C(1 ̄3)。它们的结构通过波谱方法分别鉴定为:3-O-{β-D-xylopyranosyl-(1→2)-β-D-glucopyranosyl-(1→4)-「β-D-glucopyranosy  相似文献   
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