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141.
A. Sekizawa Atsushi Taguchi Akira Watanabe Takehiko Kimura Hiroshi Saito Takumi Yanaihara Takeshi Sato 《Human genetics》1998,102(4):393-396
We have extended a previously developed method that allows prenatal DNA diagnosis of female fetuses through the isolation
of single nucleated erythrocytes from maternal blood by developing a method that can distinguish between maternal and fetal
nucleated erythrocytes. Nucleated erythrocytes were separated by a density-gradient method and then collected by micromanipulation.
Sex was determined after primer extension preamplification (PEP) of the entire genome of a single cell, and human leukocyte
antigen (HLA)-DQ α type was determined after further amplification of this gene. The HLA-DQ α genotype of fetal erythrocytes
in maternal blood samples and their corresponding paternal and maternal lymphocytes were successfully determined in all cases.
The accuracy of the method was determined by using single nucleated erythrocytes from umbilical cord blood from five normal
deliveries. This is the first demonstration that the fetal HLA-DQ α gene sequences can be identified in a small aliquot of
a single nucleated erythrocyte in maternal blood. We believe that this method ushers in a new era in which the reliability
and accuracy of noninvasive prenatal DNA diagnosis from maternal blood is markedly improved.
Received: 18 April 1997 / Accepted: 1 October 1997 相似文献
142.
Light-induced Fourier transformed infrared (FTIR) difference spectroscopy is a powerful method to study the structures and reactions of redox cofactors involved in the photosynthetic electron transport chain. So far, most of the FTIR studies of the reactions of oxygenic photosynthesis have been performed using isolated photosystem I (PSI) and photosystem II (PSII) preparations, which, however, could be modified during isolation procedures. In this study, we developed a methodology to evaluate the photosynthetic activities of thylakoids using FTIR spectroscopy. FTIR difference spectra upon successive flashes using thylakoids from spinach exhibited signals typical of the S-state cycle at the Mn4CaO5 cluster and QB reactions in PSII with period-four and -two oscillations, respectively. Similar measurement in the presence of an artificial quinone as an exogenous electron acceptor showed features specific to the S-state cycle. Simulations of the oscillation patterns provided the quantum efficiencies of the S-state cycle and electron transfer in PSII. Moreover, FTIR measurement under continuous illumination on thylakoids in the presence of DCMU showed signals due to QA reduction and P700 oxidation simultaneously. From the relative amplitudes of marker bands of QA? and P700+, the molar ratio of photoactive PSII and PSI centers in thylakoids was estimated. FTIR analyses of the photo-reactions in thylakoids, which are more intact than isolated photosystems, will be useful in investigations of the photosynthetic mechanism especially by genetic modification of photosystem proteins. 相似文献
143.
144.
A Fourier transform infrared (FTIR) difference spectrum of the oxygen-evolving Mn cluster upon the S(1)-to-S(2) transition was obtained with Ca(2+)-depleted photosystem II (PSII) membranes to investigate the structural relevance of Ca(2+) to the Mn cluster. Previously, Noguchi et al. [Biochim. Biophys. Acta 1228 (1995) 189] observed drastic changes in the carboxylate stretching region of the S(2)/S(1) FTIR spectrum upon Ca(2+) depletion, whereas Kimura and co-workers [Biochemistry 40 (2001) 14061; ibid. 41 (2002) 5844] later claimed that these changes were not ascribed to Ca(2+) depletion itself but caused by the interaction of EDTA to the Mn cluster and/or binding of K(+) at the Ca(2+) site. In the present study, the preparation of the Ca(2+)-depleted PSII sample and its FTIR measurement were performed in the absence of EDTA and K(+). The obtained S(2)/S(1) spectrum exhibited the loss of carboxylate bands at 1587/1562 and 1364/1403 cm(-1) and diminished amide I intensities, which were identical to the previous observations in the presence of EDTA and K(+). This result indicates that the drastic FTIR changes are a pure effect of Ca(2+) depletion, and provides solid evidence for the general view that Ca(2+) is strongly coupled with the Mn cluster. 相似文献
145.
Toshio Yamaguchi Fumiya Kurosaki Dae-Yeon Suh Ushio Sankawa Mizue Nishioka Takumi Akiyama Masaaki Shibuya Yutaka Ebizuka 《FEBS letters》1999,460(3)
Chalcone synthase (CHS) and stilbene synthase (STS) are related plant polyketide synthases belonging to the CHS superfamily. CHS and STS catalyze common condensation reactions of p-coumaroyl-CoA and three C2-units from malonyl-CoA but different cyclization reactions to produce naringenin chalcone and resveratrol, respectively. Using purified Pueraria lobata CHS and Arachis hypogaea STS overexpressed in Escherichia coli, bisnoryangonin (BNY, the derailed lactone after two condensations) and p-coumaroyltriacetic acid lactone (the derailed lactone after three condensations) were detected from the reaction products. More importantly, we found a cross-reaction between CHS and STS, i.e. resveratrol production by CHS (2.7–4.2% of naringenin) and naringenin production by STS (1.4–2.3% of resveratrol), possibly due to the conformational flexibility of their active sites. 相似文献
146.
Perceived swallowing problems and mortality risk in very elderly people ≥85 years old: Results of the Tokyo Oldest Old Survey on Total Health study
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147.
Kiichiro Teruya Yoshihito Daimon Xiao-Yan Dong Yoshinori Katakura Takumi Miura Akira Ichikawa Tsukasa Fujiki Makiko Yamashita Tetsuya Mori Hideya Ohashi Sanetaka Shirahata 《Cytotechnology》2005,47(1-3):29-36
The cell line D29, which was easily and rapidly established by the promoter-activated production and glutamine synthetase
hybrid system, secreted recombinant human interleukin-6 (hIL-6) at a productivity rate of 39.5 μg 10−6 cells day−1, one of the highest reported levels worldwide. The productivity rate was about 130-fold higher than that of the cell line
A7, which was established without both promoter activation and gene amplification. Although D29 cells had a high copy number
and high mRNA level of the hIL-6 gene as well as a high secretion rate of hIL-6, large amounts of intracellular hIL-6 protein
accumulated in D29 cells compared to A7 cells. Northern blotting analysis showed no change in the GRP78/BiP expression level
in D29 cells. In contrast, an electrophoresis mobility shift assay revealed strong activation of NF-κB in D29 cells. These
results suggest that large amounts of hIL-6 translated from large amounts of hIL-6 mRNA cause excess accumulation of intact
hIL-6 in the endoplasmic reticulum (ER), and that subsequent negative feedback signals via the ER overload response inhibit
hIL-6 protein secretion. To enhance the hIL-6 productivity rate of D29 cells by releasing the negative feedback signals, the
effect of pyrrolidinedithiocarbamate, an inhibitor of NF-κB activation, was examined. Suppression of NF-κB activation in D29
cells produced a 25% augmentation of the hIL-6 productivity rate. Therefore, in highly productive cells like D29 cells, the
release of negative feedback signals could increase the total amount of recombinant protein secretion. 相似文献
148.
NTH201, a novel class II KNOTTED1-like protein, facilitates the cell-to-cell movement of Tobacco mosaic virus in tobacco 总被引:1,自引:0,他引:1
Yoshii A Shimizu T Yoshida A Hamada K Sakurai K Yamaji Y Suzuki M Namba S Hibi T 《Molecular plant-microbe interactions : MPMI》2008,21(5):586-596
NTH201, a novel class II KNOTTED1-like protein gene, was cloned from tobacco (Nicotiana tabacum cv. Xanthi) and its role in Tobacco mosaic virus (TMV) infection was analyzed. Virus-induced gene silencing of NTH201 caused a delay in viral RNA accumulation as well as virus spread in infected tobacco plants. Overexpression of the gene in a transgenic tobacco plant (N. tabacum cv. Xanthi nc) infected by TMV showed larger local lesions than those of the nontransgenic plant. NTH201 exhibited no intercellular trafficking ability but did exhibit colocalization with movement protein (MP) at the plasmodesmata. When NTH201-overexpressing tobacco BY-2 cultured cells were infected with TMV, the accumulation of MP but not of viral genomic and subgenomic RNA clearly was accelerated compared with those in nontransgenic cells at an early infection period. The formation of virus replication complexes (VRC) also was accelerated in these transgenic cells. Conversely, NTH201-silenced cells showed less MP accumulations and fewer VRC formations than did nontransgenic cells. These results suggested that NTH201 might indirectly facilitate MP accumulation and VRC formation in TMV-infected cells, leading to rapid viral cell-to-cell movement in plants at an early infection stage. 相似文献
149.
150.
Takumi Higaki Yasuhiro Kadota Tatsuaki Goh Teruyuki Hayashi Natsumaro Kutsuna Toshio Sano Seiichiro Hasezawa Kazuyuki Kuchitsu 《Plant signaling & behavior》2008,3(9):700-703
Responses of plant cells to environmental stresses often involve morphological changes, differentiation and redistribution of various organelles and cytoskeletal network. Tobacco BY-2 cells provide excellent model system for in vivo imaging of these intracellular events. Treatment of the cell cycle-synchronized BY-2 cells with a proteinaceous oomycete elicitor, cryptogein, induces highly synchronous programmed cell death (PCD) and provide a model system to characterize vacuolar and cytoskeletal dynamics during the PCD. Sequential observation revealed dynamic reorganization of the vacuole and actin microfilaments during the execution of the PCD. We further characterized the effects cryptogein on mitotic microtubule organization in cell cycle-synchronized cells. Cryptogein treatment at S phase inhibited formation of the preprophase band, a cortical microtubule band that predicts the cell division site. Cortical microtubules kept their random orientation till their disruption that gradually occurred during the execution of the PCD twelve hours after the cryptogein treatment. Possible molecular mechanisms and physiological roles of the dynamic behavior of the organelles and cytoskeletal network in the pathogenic signal-induced PCD are discussed.Key words: actin microfilament, cell cycle, cryptogein, microtubules, nuclei, programmed cell death, tobacco BY-2 cells, vacuoles 相似文献