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61.
Ghanem ME Yoshida C Nishibori M Nakao T Yamashiro H 《Animal reproduction science》2005,85(3-4):193-199
A female Japanese Black calf was born on 25 March 2003 at Hiroshima University Farm as a co-twin to a male Japanese Black calf. The male calf showed no external urogenital abnormalities. The absence of anal opening and external features of freemartinism were observed in the female. A small opening to the vulva (about 1.5 cm in length) with fused lips and a prominent clitoris were seen. The hair around the vulva was 3.5 cm in length and was heavy and dense. The distance from the vulva to the atretic anus was 9.0 cm. There were no other detectable abnormalities on physical examination. The PCR-based DNA test showed male-specific sequences confirming the calf to be freemartin. At autopsy 1 day after the calf birth, the gonads were found to be small and hard and the left uterine horn showed segmental aplasia near its proximal end. Two seminal glands (remnants of mesonephric duct) were located on both sides of the uterine body. A cervix was absent. The vagina was underdeveloped and looked like a tubual structure. The rectal end was closed, while the distance from the end of the atretic rectum to the absent anal opening was about 4.0 cm. On histological examination, the gonads exhibited extensive morphologic alteration; there was no cortex with the absence of ovarian structures. The seminal glands consisted of hypoplastic glandular tissue surrounded by extensive fibrous connective tissue. In conclusion, this is a case report of a freemartin with atresia recti and ani. 相似文献
62.
Role of FRIGIDA and FLOWERING LOCUS C in determining variation in flowering time of Arabidopsis
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Shindo C Aranzana MJ Lister C Baxter C Nicholls C Nordborg M Dean C 《Plant physiology》2005,138(2):1163-1173
Arabidopsis (Arabidopsis thaliana) accessions provide an excellent resource to dissect the molecular basis of adaptation. We have selected 192 Arabidopsis accessions collected to represent worldwide and local variation and analyzed two adaptively important traits, flowering time and vernalization response. There was huge variation in the flowering habit of the different accessions, with no simple relationship to latitude of collection site and considerable diversity occurring within local regions. We explored the contribution to this variation from the two genes FRIGIDA (FRI) and FLOWERING LOCUS C (FLC), previously shown to be important determinants in natural variation of flowering time. A correlation of FLC expression with flowering time and vernalization was observed, but it was not as strong as anticipated due to many late-flowering/vernalization-requiring accessions being associated with low FLC expression and early-flowering accessions with high FLC expression. Sequence analysis of FRI revealed which accessions were likely to carry functional alleles, and, from comparison of flowering time with allelic type, we estimate that approximately 70% of flowering time variation can be accounted for by allelic variation of FRI. The maintenance and propagation of 20 independent nonfunctional FRI haplotypes suggest that the loss-of-function mutations can confer a strong selective advantage. Accessions with a common FRI haplotype were, in some cases, associated with very different FLC levels and wide variation in flowering time, suggesting additional variation at FLC itself or other genes regulating FLC. These data reveal how useful these Arabidopsis accessions will be in dissecting the complex molecular variation that has led to the adaptive phenotypic variation in flowering time. 相似文献
63.
Morton MF Liu PQ Reik A de la Rosa R Mendel M Li XY Case C Pabo C Moreno V Pyati J Shankley NP 《Regulatory peptides》2005,129(1-3):227-232
Designed zinc finger proteins (ZFPs) regulate expression of target genes when coupled to activator or repressor domains. Transfection of ZFPs into cell lines can create expression systems where the targeted endogenous gene is transcribed and the protein of interest can be investigated in its own cellular context. Here we describe the pharmacological investigation of an expression system generated using CCK2 receptor-selective ZFPs transfected into human embryonic kidney cells (HEKZFP system). The receptors expressed in this system, in response to ZFP expression, were functional in calcium mobilization studies and the potency of the agonists investigated was consistent with their action at CCK2 receptors (CCK-8S pA50 = 9.05+/-0.11, pentagastrin pA50 = 9.11+/-0.13). In addition, binding studies were conducted using [125I]-BH-CCK-8S as radioligand. The saturation binding analysis of this radioligand was consistent with a single population of high affinity CCK receptors (pK(D) = 10.24). Competition studies were also conducted using a number of previously well-characterized CCK-receptor selective ligands; JB93182, YF476, PD-134,308, SR27897, dexloxiglumide, L-365,260 and L-364,718. Overall, the estimated affinity values for these ligands were consistent with their interaction at CCK2 receptors. Therefore, CCK2 receptors up-regulated using zinc finger protein technology can provide an alternative to standard transfection techniques for the pharmacological analysis of compounds. 相似文献
64.
Mikamo E Tanaka C Kanno T Akiyama H Jung G Tanaka H Kawai T 《Journal of structural biology》2005,151(1):106-110
The native polysomes of Saccharomyces cerevisiae were visualized in liquid solution by atomic force microscopy without external contrasting, such as shadowing and negative staining. This study showed native polysomes as lined particle with a height of ca. 27 nm, which is agreement with the height of 80S ribosomes in previous study. We found a small subparticle, located in a ring-shape or at the end of a linear structure, and visualized mRNA chains between adjacent ribosomes. Although the structures of polysomes have been studied for decades, it has remained difficult to visualize the native three-dimensional form. By the observation in liquid solution, we temporarily stopped the translation using an antibiotic to presenting the native three-dimensional structure and function of the polysomes. Our results provide not only new findings on native eukaryotic polysomes, but also great potential to visualize the influence of various environmental conditions on polysomes. 相似文献
65.
Integrating information in the molecular biosciences involves more than the cross-referencing of sequences or structures. Experimental protocols, results of computational analyses, annotations and links to relevant literature form integral parts of this information, and impart meaning to sequence or structure. In this review, we examine some existing approaches to integrating information in the molecular biosciences. We consider not only technical issues concerning the integration of heterogeneous data sources and the corresponding semantic implications, but also the integration of analytical results. Within the broad range of strategies for integration of data and information, we distinguish between platforms and developments. We discuss two current platforms and six current developments, and identify what we believe to be their strengths and limitations. We identify key unsolved problems in integrating information in the molecular biosciences, and discuss possible strategies for addressing them including semantic integration using ontologies, XML as a data model, and graphical user interfaces as integrative environments. 相似文献
66.
Yamaguchi T Yamazaki T Inoue M Mashida C Kawagoe K Ogawa M Shiga S Nakagawa Y Kishimoto T Kurane I Ouchi K Ohzeki T 《FEMS immunology and medical microbiology》2005,43(1):21-27
Simkania negevensis has been associated with bronchiolitis in infants and community-acquired pneumonia in adults. Reports of exposure to this microorganism are only available from Israel, North America and Western Europe. Currently, no standard method for diagnosis of S. negevensis infection has been established nor have prevalence rates been shown in Japan. For the first time we demonstrated the ability of the microimmunofluorescence (MIF) test to detect S. negevensis-specific immunoglobulin G and exposure to S. negevensis in Japan. The positive rate in healthy volunteers was 4.3% (25/588), with rates increasing with age. Results indicate the usefulness of the MIF test as a serological method for detecting S. negevensis-specific antibodies. A standard serological test for infection with S. negevensis is needed. 相似文献
67.
Inactivation of NF1 in CNS causes increased glial progenitor proliferation and optic glioma formation 总被引:7,自引:0,他引:7
Zhu Y Harada T Liu L Lush ME Guignard F Harada C Burns DK Bajenaru ML Gutmann DH Parada LF 《Development (Cambridge, England)》2005,132(24):5577-5588
The gene responsible for neurofibromatosis type 1 (NF1) encodes a tumor suppressor that functions as a negative regulator of the Ras proto-oncogene. Individuals with germline mutations in NF1 are predisposed to the development of benign and malignant tumors of the peripheral and central nervous system (CNS). Children with this disease suffer a high incidence of optic gliomas, a benign but potentially debilitating tumor of the optic nerve; and an increased incidence of malignant astrocytoma, reactive astrogliosis and intellectual deficits. In the present study, we have sought insight into the molecular and cellular basis of NF1-associated CNS pathologies. We show that mice genetically engineered to lack NF1 in CNS exhibit a variety of defects in glial cells. Primary among these is a developmental defect resulting in global reactive astrogliosis in the adult brain and increased proliferation of glial progenitor cells leading to enlarged optic nerves. As a consequence, all of the mutant optic nerves develop hyperplastic lesions, some of which progress to optic pathway gliomas. These data point to hyperproliferative glial progenitors as the source of the optic tumors and provide a genetic model for NF1-associated astrogliosis and optic glioma. 相似文献
68.
Matrix metalloproteinase-9 in macrophages induces thymic neovascularization following thymocyte apoptosis 总被引:3,自引:0,他引:3
Matrix metalloproteinase-9 (MMP-9) has been implicated in the degradation of the extracellular matrix in a variety of physiological and pathological processes. We found that MMP-9 expression in thymuses of BALB/c mice that had been injected with anti-CD3 Ab to induce thymocyte apoptosis was increased both at mRNA and protein levels. Macrophages are shown to be the principal stromal cells responsible for phagocytosis of dying thymocytes, and macrophages were found to constitutively express MMP-9. The activity of plasmin, which is known as one of the activators for MMP-9, was increased in the thymuses with MMP-9 activation. Binding of Ab HUIV26, which recognizes a cryptic epitope on collagen type IV following proteolytic cleavage, was found to be reduced in MMP-9 knockout mice, suggesting that collagen type IV is a substrate of MMP-9. Although the formation of thymic neovessels was found following thymocyte apoptosis, it was diminished in anti-CD3 Ab-injected MMP-9 knockout mice. In vivo administration of Ab HUIV26 resulted in a reduction of thymic neovascularization. After clearance of apoptotic thymocytes, the number of macrophages in the thymuses was decreased, and this decrease was delayed by blocking of HUIV26 epitope. Taken together, our results suggest that MMP-9 expression in macrophages mediates degradation of collagen type IV and facilitates their migration from the thymus after clearance of apoptotic thymocytes. These studies demonstrate a potential role of macrophage MMP-9 in the remodeling of thymic extracellular matrix following thymocyte apoptosis. 相似文献
69.
Tumor necrosis factor-alpha (TNF-alpha) binds to TNF-alpha receptors (TNFR) to produce a hexameric (TNF-alpha)(3)-(TNFR)(3) structure that stimulates apoptosis. We found by using ELISA that TNF-alpha binds to the glycosylphosphatidylinositol (GPI) anchor glycans of carcinoembryonic antigen, human placental alkaline phosphatase (hAP), and Tamm-Horsfall glycoprotein. These binding abilities were inhibited by 10(-6)M mannose-6-phosphate. Treatment of hAP with mild acid and phosphatase, which releases the N-acetylglucosamine (GlcNAc) beta1 -->phosphate-->6 residue from the GPI-anchor glycan of hAP, abrogated the binding of TNF-alpha to hAP. Thus, TNF-alpha binds to the GlcNAcbeta1-->phosphate-->6Man residue in GPI-anchor glycans. To investigate whether the carbohydrate-binding ability of TNF-alpha is related to its physiological functions, human lymphoma U937 cells were used. TNF-alpha stimulates U937 cell apoptosis in a dose-dependent manner and the presence of mannose-6-phosphate inhibited this. TNF-alpha-dependent tyrosine phosphorylation of several proteins in U937 cells was also diminished by mannose-6-phosphate. Phosphatidylinositol-specific phospholipase C-pretreatment also inhibited this tyrosine phosphorylation. These data suggest that TNF-alpha stimulates U937 cell apoptosis by forming a high-affinity nanomeric (TNF-alpha)(3)-(TNFR)(3)-(GPI-anchored glycan)(3) complex. The GPI-anchored glycoprotein involved remains to be identified. 相似文献
70.
Kominato Y Ueki M Iida R Kawai Y Nakajima T Makita C Itoi M Tajima Y Kishi K Yasuda T 《The FEBS journal》2006,273(13):3094-3105