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41.
42.
Murakami K Irie K Morimoto A Ohigashi H Shindo M Nagao M Shimizu T Shirasawa T 《The Journal of biological chemistry》2003,278(46):46179-46187
Cerebral amyloid angiopathy (CAA) due to beta-amyloid (Abeta) is one of the specific pathological features of familial Alzheimer's disease. Abeta mainly consisting of 40- and 42-mer peptides (Abeta40 and Abeta42) exhibits neurotoxicity and aggregative abilities. All of the variants of Abeta40 and Abeta42 found in CAA were synthesized in a highly pure form and examined for neurotoxicity in PC12 cells and aggregative ability. All of the Abeta40 mutants at positions 22 and 23 showed stronger neurotoxicity than wild-type Abeta40. Similar tendency was observed for Abeta42 mutants at positions 22 and 23 whose neurotoxicity was 50-200 times stronger than that of the corresponding Abeta40 mutants, suggesting that these Abeta42 mutants are mainly involved in the pathogenesis of CAA. Although the aggregation of E22G-Abeta42 and D23N-Abeta42 was similar to that of wild-type Abeta42, E22Q-Abeta42 and E22K-Abeta42 aggregated extensively, supporting the clinical evidence that Dutch and Italian patients are diagnosed as hereditary cerebral hemorrhage with amyloidosis. In contrast, A21G mutation needs alternative explanation with the exception of physicochemical properties of Abeta mutants. Attenuated total reflection-Fourier transform infrared spectroscopy spectra suggested that beta-sheet content of the Abeta mutants correlates with their aggregation. However, beta-turn is also a critical secondary structure because residues at positions 22 and 23 that preferably form two-residue beta-turn significantly enhanced the aggregative ability. 相似文献
43.
Kawase T Okuda K Saito Y Amizuka N Suzuki H Yoshie H 《In vitro cellular & developmental biology. Animal》2005,41(5-6):171-176
Summary Platelet-rich plasma (PRP) has been used to promote periodontal regeneration following the premise that constituent transforming
growth factor-β1 (TGF-β1) and platelet-derived growth factor-AB will stimulate cell proliferation at the site of application.
In previous studies, we demonstrated that PRP mimics TGF-β1 to modulate proliferation in a cell type-specific manner, that
fibrin clot formation by PRP upregulates type I collagen, and that an unidentified factor(s) in PRP increases alkaline phosphatase
(ALP) activity in human periodontal ligament (PDL) cell cultures. We have now examined the effects of PRP on in vitro mineralization.
Platelet-rich plasma and PDL cells were prepared from human adult volunteers or rats. After 20 d of continuous treatment with
PRP in dexamethazone (Dex)-containing osteogenic medium, PRP time dependently promoted mineralization by rat PDL cells but
failed to fully induce the osteoblastic phenotype. Furthermore, when human PDL cells were induced to increase ALP activity
in osteogenic medium that lacked Dex, a condition that should delay (or suppress) osteoblastic differentiation, transmission
electron microscopy revealed that mineralized spicules were initially deposited onto PRP-derived platelet aggregates. Taken
together with our previous data, these findings suggest that PRP provides platelet aggregates as nuclei to initiate mineralization
while stimulating PDL cell proliferation, differentiation, and collagen production. The combination of these effects may effectively
mediate PRP's ability to promote regeneration of periodontal tissue, including skeletal tissue, at the site of injury. 相似文献
44.
Circadian rhythm is a self-sustaining oscillation whose period length coincides with the 24-hour day-night cycle. A powerful tool for circadian clock research is the real-time automated bioluminescence monitoring system in which a promoter region of a clock-controlled gene is fused to a luciferase reporter gene and rhythmic regulation of the promoter activity is monitored as bioluminescence. In the present study, we greatly improved the bioluminescence reporter system in the cyanobacterium Synechocystis sp. strain PCC 6803. We fused an 805-bp promoter region of the dnaK gene seamlessly to the luxA coding sequence and integrated the P(dnaK)::luxAB fusion gene into a specific intergenic region of the Synechocystis genome (targeting site 1). The resulting new reporter strain, PdnaK::luxAB(-), showed 12 times the bioluminescence intensity of the standard reporter strain, CFC2. Furthermore, we generated strain PdnaK::luxAB(+), in which the P(dnaK)::luxAB fusion gene and the selection-marker spectinomycin resistance gene are transcribed in opposite directions. The PdnaK::luxAB(+) strain showed 19 times the bioluminescence intensity of strain CFC2. The procedures used to increase the bioluminescence intensity are especially useful for bioluminescence monitoring of genes with low promoter activity. In addition, these reporter constructs facilitate bioluminescence monitoring of any gene because the promoter fragments they contain can easily be replaced by digestion with unique restriction enzymes. They would therefore contribute to a genome-wide analysis of gene expression in Synechocystis. 相似文献
45.
Production of human erythropoietin by chimeric chickens 总被引:1,自引:0,他引:1
Kodama D Nishimiya D Iwata K Yamaguchi K Yoshida K Kawabe Y Motono M Watanabe H Yamashita T Nishijima K Kamihira M Iijima S 《Biochemical and biophysical research communications》2008,367(4):834-839
The use of transgenic avian allows cost effective and safe production of pharmaceutical proteins. Here, we report the successful production of chimeric chickens expressing human erythropoietin (hEpo) using a high-titer retroviral vector. The hEpo expressed by transgenic hens accumulated abundantly in egg white and had N- and O-linked carbohydrates. While attachment of terminal sialic acid and galactose was incomplete, portions of N- and O-linked carbohydrates were present. In vitro biological activity of egg white-hEpo was comparable to that produced by recombinant CHO cells. 相似文献
46.
Anondho Wijanarko Dianursanti Misri Gozan Sang Made Krisna Andika Paramita Widiastuti Heri Hermansyah Arief Budi Witarto Kazuhiro Asami Roekmijati Widaningroem Soemantojo Kazuhisa Ohtaguchi Song Seung Koo 《Biotechnology and Bioprocess Engineering》2006,11(6):484-488
Alteration of illumination with optimum carbon dioxide fixation-based curve in this research successfully enhanced the CO2-fixation (qco2) capability ofChlorella vulgaris Buitenzorg cultivated in a bubble column photo bioreactor. The level of CO2 fixation was up to 1.91 times that observed from cultivation with intensification of illumination on an optimum growth-based curve. During 144 h of cultivation, alteration of light intensity on an optimum CO2-fixation-based curve produced a qCO2 of 6.68 h?1. Increases in light intensity based on a curve of optimum CO2-fixation produced a final cell concentration of about 5.78 g/L. Both cultivation methods were carried out under ambient pressure at a temperature of 29°C with a superficial gas velocity of 2.4 m/h (UG). Cells were grown on Beneck medium in a 1.0 L Bubble Column Photo bioreactor illuminated by aPhillips Halogen Lamp (20 W/12 V/50 Hz). The inlet gas had a carbon dioxide content of 10%. 相似文献
47.
Tomonori Deguchi Kazuhiro E. Fujimori Takashi Kawasaki Hajime Ohgushi Shunsuke Yuba 《Gene expression patterns : GEP》2009,9(5):341-347
Prox1 is a prospero-related homeobox gene. Prox1 is expressed in various internal organs and is related to those differentiations. Small fishes such as the zebrafish and the medaka are useful model animals in the clarification of the mechanism of development. The zebrafish prox1 is also identified, and it contributes to clarifying the function of prox1. However, it is necessary to note that many genes are duplicated in teleost fishes. In this study, we identified the orthologs of the mammalian prox1 gene in the medaka. The gene was also duplicated in the medaka, and we named it prox1a and prox1b. In silico analysis from the perspective of synteny indicated that medaka prox1a was similar to the prox1 gene of other vertebrates. Medaka prox1a was expressed in all internal organs that we have examined by RT-PCR. In contrast, medaka prox1b expression was limited to the brain, heart, liver, kidney, thymus, gill, testis, and ovary. This suggests that the two prox1 genes do not have a complementary relationship. In addition, we examined their expression patterns during embryonic development using whole-mount in situ hybridization. The expression pattern of prox1a showed a pattern similar to that of zebrafish prox1. In contrast, medaka prox1b was expressed asymmetrically in part of the central nervous system, especially strongly in the right side of the habenula. 相似文献
48.
Microsatellite polymorphism in the human heme oxygenase-1 gene promoter and its application in association studies with Alzheimer and Parkinson disease 总被引:16,自引:0,他引:16
Teiko Kimpara A. Takeda Koichi Watanabe Yasuto Itoyama Shuntaro Ikawa Minro Watanabe Hiroyuki Arai Hidetada Sasaki Susumu Higuchi Naoshi Okita Sadao Takase Hiroshi Saito Kazuhiro Takahashi Shigeki Shibahara 《Human genetics》1997,100(1):145-147
Oxidative stress has been suggested to be involved in the pathogenesis of neurodegenerative diseases, such as Alzheimer disease
(AD) and Parkinson disease (PD). Heme oxygenase-1 (HO-1), a key enzyme in heme catabolism, also functions as an antioxidant
enzyme. Here, we show that a (GT)n repeat in the human HO-1 gene promoter region is highly polymorphic, although no particular alleles are associated with AD
or PD. This newly identified genetic marker should allow us to study the possible involvement of HO-1 in certain human diseases.
Received: 5 November 1996 / Accepted: 18 February 1997 相似文献
49.
Gene expression profile analysis of the mouse liver during bacteria-induced fulminant hepatitis by a cDNA microarray system 总被引:5,自引:0,他引:5
Dong H Toyoda N Yoneyama H Kurachi M Kasahara T Kobayashi Y Inadera H Hashimoto S Matsushima K 《Biochemical and biophysical research communications》2002,298(5):675-686
Fulminant hepatic failure (FHF) is a disease characterized by sudden and severe impairment of liver function. To elucidate the mechanism involved in FHF, we adopted a murine model of FHF by administrating mice with heat-killed Propionibacterium acnes (P. acnes), followed by a low dose of lipopolysaccharide (LPS), and analyzed the dynamic change of gene expression profile of the murine liver using an in-house cDNA microarray system which contained most of the cDNAs encoding chemokines/cytokines and their receptors (33 chemokines/21 chemokine receptors, 28 cytokines/35 cytokine receptors) as well as 230 liver related proteins mostly selected by serial analysis of gene expression (SAGE). Among them, 335 genes were found to differ by more than 2-fold in at least one time point comparing with normal liver. Hierarchical cluster analysis revealed that except for a few genes, such as heme oxygenase (HO)-1 and nicotinamide N-methyltransferase (NNMT) of which expression increased, the expression of most of the genes encoding drug metabolizing enzymes decreased with the progress of the disease. The expression of the genes encoding chemokines/cytokines was dramatically changed, such as Mig, IP-10, RANTES, TNF-alpha, and IFN-gamma. In addition, the expression of those that were not previously linked to this murine model was also identified to be changed. These include endogenous IL-18 binding protein (IL-18BP), CXCL16 (the ligand of Bonzo, CXCR6) as well as ESTs. Taken together this study has shown the systemic and comprehensive gene expression profile during FHF and may contribute to better understanding of the mechanism of FHF. 相似文献
50.
Mori T Maruyama N Nishizawa K Higasa T Yagasaki K Ishimoto M Utsumi S 《The Plant journal : for cell and molecular biology》2004,40(2):238-249
Glycinin (11S) and beta-conglycinin (7S) are major storage proteins in soybean (Glycine max L.) seeds and accumulate in the protein storage vacuole (PSV). These proteins are synthesized in the endoplasmic reticulum (ER) and transported to the PSV by vesicles. Electron microscopic analysis of developing soybean cotyledons of the wild type and mutants with storage protein composition different from that of the wild type showed that there are two transport pathways: one is via the Golgi and the other bypasses it. Golgi-derived vesicles were observed in all lines used in this study and formed smooth dense bodies with a diameter of 0.5 to several micrometers. ER-derived protein bodies (PBs) with a diameter of 0.3-0.5 microm were observed at high frequency in the mutants containing higher amount of 11S group I subunit than the wild type, whereas they were hardly observed in the mutants lacking 11S group I subunit. These indicate that pro11S group I may affect the formation of PBs. Thus, the composition of newly synthesized proteins in the ER is important in the selection of the transport pathways. 相似文献