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151.
Yamagishi Y Horie Y Kato S Kajihara M Tamai H Granger DN Ishii H 《American journal of physiology. Gastrointestinal and liver physiology》2002,282(4):G640-G646
Whereas both ethanol and gut ischemia/reperfusion (I/R) are known to alter hepatic microvascular function, little is known about the influence of ethanol consumption on the hepatic microvascular responses to I/R. The objective of this study was to determine whether acute ethanol administration exacerbates the hepatic microvascular dysfunction induced by gut I/R. Rats were exposed to gut ischemia for 30 min followed by reperfusion. Intravital videomicroscopy was used to monitor leukocyte recruitment and the number of nonperfused sinusoids (NPS). Plasma alanine aminotransferase (ALT), tumor necrosis factor-alpha (TNF-alpha), and endotoxin concentrations were monitored. In separate experiments, ethanol was administered 15 min or 24 h before gut ischemia. In control rats, gut I/R increased the number of stationary leukocytes and NPS. It also elevated the plasma ALT, TNF-alpha, and endotoxin with a corresponding increase in intestinal mucosal permeability. Low-dose ethanol consumption 15 min before gut ischemia blunted the gut I/R-induced leukostasis and elevations in plasma TNF-alpha and ALT. However, high-dose ethanol consumption aggravated the gut I/R-induced increases in leukostasis and increases in plasma endotoxin and ALT. When ethanol was administered 24 h before, high-dose ethanol aggravated the gut I/R-induced hepatocellular injury, but low-dose ethanol did not have any effects on it. These results suggest that low-dose ethanol consumption shortly before gut ischemia attenuates the hepatic inflammatory responses, microvascular dysfunction, and hepatocellular injury elicited by gut I/R, whereas high-dose ethanol consumption appears to significantly aggravate these gut I/R-induced responses. 相似文献
152.
Fujita H Koji T Kitagawa N Tsutsumi K Abe K Kaminogo M Shibata S 《Cellular and molecular neurobiology》2002,22(4):393-406
1. For a better understanding of the biological features of astrocytic tumors, we investigated apoptosis and its pathway, especially in the interaction between Fas and Fas ligand (FasL).2. We examined the presence of apoptosis in human astrocytic brain tumors by terminal deoxynucleotidyl transferase (TdT)-mediated d-UTP-biotin nick end labeling (TUNEL) and then apoptotic index (AI) was calculated. We also examined the distribution of Fas and FasL-positive tumor cells immunohistochemically. Labeling index (LI) for Fas and FasL was calculated as Fas-LI and FasL-LI, respectively, and compared to AI.3. Tumor cells expressing both Fas and FasL were TUNEL positive. Such cells were distributed sparsely in low-grade astrocytomas, but focally in glioblastomas. There was a close correlation among AI, Fas-LI, and FasL-LI, and astrocytic tumors with higher AI were associated with a longer survival time than that with lower AI.4. It was concluded that the Fas system may be involved in the apoptosis of astrocytic tumors, and AI can be a useful parameter for assessing prognosis of astrocytic tumors. 相似文献
153.
Human recombinant stem cell factor promotes spermatogonial proliferation,but not meiosis initiation in organ culture of newt testis fragments 总被引:3,自引:0,他引:3
Abé K Jin Y Yamamoto T Abé S 《Biochemical and biophysical research communications》2002,294(3):695-699
We previously showed that mammalian FSH stimulates the proliferation of newt spermatogonia and induces their differentiation into primary spermatocytes in vitro. In the current study, to examine a possibility that stem cell factor (SCF) is involved in the proliferation of newt spermatogonia and/or their differentiation into primary spermatocytes, human recombinant SCF (rhSCF) was added to organ culture of testicular fragments. rhSCF was found to stimulate the spermatogonial proliferation and the spermatogonia progressed to the seventh generation that is the penultimate stage before primary spermatocyte stage. However, the spermatogonia did not differentiate into primary spermatocytes, but instead died of apoptosis. These results indicate that rhSCF promotes the proliferation of newt spermatogonia, but not the initiation of meiosis. 相似文献
154.
Kataoka TR Morii E Oboki K Jippo T Maeyama K Kitamura Y 《Biochemical and biophysical research communications》2002,291(1):111-115
Structural localization of a peptide region, KRQPRNPKTDKLVNE, in the catalytic subunit of (Na(+) + K(+))-ATPase was investigated using a specific antibody directed against this peptide in cultured African green monkey kidney CV-1 cells. Immunofluorescence staining of frozen cell sections shows that an anti-KRQPRNPKTDKLVNE antibody (SSA95) interacts with its antigenic site and binds to the extracellular side of the cell membrane. Indirect immunofluorescence and flow cytometric analyses confirmed the presence of this epitope on intact cell surfaces. These results suggest that the KRQPRNPKTDKLVNE region of the (Na(+) + K(+))-ATPase is expressed on the cellular membrane surface. 相似文献
155.
Aoki N Kimura S Oikawa K Nochi H Atsuta Y Kobayashi H Sato K Katagiri M 《Biochemical and biophysical research communications》2002,291(2):296-304
DAP12 is an immunoreceptor tyrosine-based activation motif (ITAM)-bearing transmembrane adapter molecule that is associated with the NK-activating receptors. DAP12 is expressed not only in NK cells, but also in myeloid cells. Previously, we reported that DAP12 was likely to be involved in monocyte differentiation to macrophage. In this study, we established the mutant DAP12-M1 transfectants (Y76F-M1) that have mutation at their ITAM motifs. We observed that Y76F-M1 cells could not differentiate to macrophages by stimulation via DAP12, whereas wild type DAP12 transfectants (FDAP-M1) could. Furthermore, we demonstrated that the apoptosis signal mediated by LPS was inhibited in Y76F-M1 cells, but was augmented in FDAP-M1 cells. In contrast to the LPS-mediated apoptosis, the combination of LPS and DAP12 stimulation showed good cell viability in FDAP-M1 cells. Collectively our studies demonstrated that DAP12 has a critical role for macrophage differentiation and LPS induced apoptosis in M1 leukemia cells. 相似文献
156.
We have employed a structure-based design to construct a small folding domain from the F-actin bundling protein villin that contains the amino acids necessary for the DNA binding of the basic leucine zipper protein GCN4 and have compared its DNA binding with GCN4. The monomeric motif folds into a stable domain and binds DNA in a rigid-body mechanism, while its affinity is not higher than that of the basic region peptide. The addition of the leucine zipper region to the folded domain restored its sequence-specific DNA binding comparable to that of GCN4. Unlike the monomeric folded domain, its leucine zipper derivative undergoes a conformational change upon DNA binding. CD spectral and thermodynamic studies indicate that the DNA-contacting region is folded in the presence or absence of DNA and suggest that the junction between the DNA-contacting and the leucine zipper regions transits to a helix in the presence of DNA. These results demonstrate that the structural transition outside the direct-contacting region, which adjusts the precise location of the DNA-contacting region, plays a critical role in the specific complex formation of basic leucine zipper proteins. 相似文献
157.
Advanced glycation end products-induced apoptosis and overexpression of vascular endothelial growth factor in bovine retinal pericytes. 总被引:14,自引:0,他引:14
Sho-ichi Yamagishi Shinjiro Amano Yosuke Inagaki Tamami Okamoto Kohachiro Koga Nobuyuki Sasaki Hiroshi Yamamoto Masayoshi Takeuchi Zenji Makita 《Biochemical and biophysical research communications》2002,290(3):973-978
The influence of advanced glycation end products (AGEs) on apoptotic cell death and vascular endothelial growth factor (VEGF) gene expression in cultured bovine retinal pericytes was investigated. When pericytes were incubated with three immunochemically distinct AGEs, which were prepared in vitro by incubating bovine serum albumin with glucose, glyceraldehyde, or glycolaldehyde, apoptotic cell death and DNA ladder formation were significantly induced. The cytopathic effects of glyceraldehyde- or glycolaldehyde-derived AGEs were significantly enhanced in AGE receptor-transfected pericytes. Furthermore, all of these AGEs were found to upregulate the secretory forms of VEGF mRNA levels in retinal pericytes. These results suggest that AGEs disturbed retinal microvascular homeostasis by inducing pericyte apoptosis and VEGF overproduction and thus were involved in the pathogenesis of early phase diabetic retinopathy. 相似文献
158.
Fukai Y Nihei C Kawai K Yabu Y Suzuki T Ohta N Minagawa N Nagai K Kita K 《Parasitology international》2003,52(3):237-241
Cyanide-insensitive trypanosome alternative oxidase (TAO) is the terminal oxidase of the respiratory chain of long slender bloodstream forms of the African trypanosome, which causes sleeping sickness in humans and nagana in cattle. TAO has been targeted for the development of anti-trypanosomal drugs, because it does not exist in the host. In this study, we established a system for overproduction of highly active TAO in Eschericia coli heme-deficient mutant. Kinetic analysis of recombinant enzyme and TAO in Trypanosoma brucei brucei mitochondria revealed that recombinant TAO retains the properties of native enzyme, indicating that recombinant TAO is quite valuable for further biochemical study of TAO. 相似文献
159.
Natural<Superscript>15</Superscript> N Abundance of Plants and Soil N in a Temperate Coniferous Forest 总被引:3,自引:0,他引:3
Keisuke?Kobakkoba@depe.titech.ac.jp" title="kkoba@i.kyoto-u.ac.jp kkoba@depe.titech.ac.jp" itemprop="email" data-track="click" data-track-action="Email author" data-track-label="">Email author Muneto?Hirobe Lina?Koyama Ayato?Kohzu Naoko?Tokuchi Knute John?Nadelhoffer Eitaro?Wada Hiroshi?Takeda 《Ecosystems》2003,6(5):457-469
Measurement of nitrogen isotopic composition (15N) of plants and soil nitrogen might allow the characteristics of N transformation in an ecosystem to be detected. We tested the measurement of 15N for its ability to provide a picture of N dynamics at the ecosystem level by doing a simple comparison of 15N between soil N pools and plants, and by using an existing model. 15N of plants and soil N was measured together with foliar nitrate reductase activity (NRA) and the foliar NO3– pool at two sites with different nitrification rates in a temperature forest in Japan. 15N of plants was similar to that of soil NO3– in the high-nitrification site. Because of high foliar NRA and the large foliar NO3– pool at this site, we concluded that plant 15N indicated a great reliance of plants on soil NO3– there. However, many 15N of soil N overlapped each other at the other site, and 15N could not provide definitive evidence of the N source. The existing model was verified by measured 15N of soil inorganic N and it explained the variations of plant 15N between the two sites in the context of relative importance of nitrification, but more information about isotopic fractionations during plant N uptake is required for quantitative discussions about the plant N source. The model applied here can provide a basis to compare 15N signatures from different ecosystems and to understand N dynamics. 相似文献
160.
Significance of venous anastomosis in fingertip replantation 总被引:5,自引:0,他引:5
Adequate venous outflow is the most important factor for successful fingertip replantation. The authors have attempted venous anastomosis in all cases of fingertip replantation to overcome postoperative congestion. In this article, the significance of venous repair for fingertip replantation is described from the authors' results of 64 complete fingertip amputations in 55 consecutive patients, which were replanted from January of 1996 to June of 2001. The overall survival rate was 86 percent. Of the 44 replantations in zone I, 37 survived, and the success rate was 84 percent. Of the 20 replantations in zone II, 18 survived, and the success rate was 90 percent. Venous anastomosis was attempted in all cases, but it was possible in 39 zone I and in all zone II replantations. For arterial repair, vein grafts were necessary in 17 of the 44 zone I and in one of the 20 zone II replantations; for venous repair, they were necessary in six zone I replantations and one zone II replantation. Postoperative vascular complications occurred in 15 replantations. There were five cases of arterial thrombosis and 10 cases of venous congestion. Venous congestion occurred in nine zone I and one zone II replantations. In five of these 10 replantations, venous anastomosis was not possible. In another five replantations, venous outflow was established at the time of surgery, but occlusion occurred subsequently. Except for the five failures resulting from arterial thrombosis, successful venous repair was possible in 49 of 59 replantations (83 percent). Despite the demand for skillful microsurgical technique and longer operation time, the authors' results using venous anastomosis in successful fingertip replantations are encouraging. By performing venous anastomosis, external bleeding can be avoided and a higher survival rate can be achieved. Venous anastomosis for fingertip replantation is a reliable and worthwhile procedure. 相似文献