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1.
No consensus exists concerning the mechanisms, distribution,or adaptive significance of consciousness. Agreement on anyone of these issues would aid in resolving others. Given a reliablebehavioral or neuroanatomical test for consciousness, we couldmap its distribution and describe its evolution. Conversely,if we knew its distribution, we could assess its adaptive valueand look for similarly distributed neuroanatomies to help usget at its mechanisms. Morgan's Canon—the rule that we should avoid attributinghumanlike mental states to other animals whenever possible—impedesthe use of the comparative method in unraveling this knot. Ifinterpreted in this context as a parsimony criterion, Morgan'sCanon is logically equivalent to epiphenomenalism. It is parsimoniousif and only if conscious mental events play no causal role inhuman behavior and human consciousness has no adaptive significance.Rejecting this conclusion entails rejecting the parsimony interpretationof Morgan's Canon.  相似文献   
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Objectives To understand how the policy of user involvement is interpreted in health service organisations and to identify factors that influence how user involvement is put into practice.Design Ethnographic study using participant observation, interviews, and collection of documentary evidence.Setting A multiagency modernisation programme to improve stroke services in two London boroughs.Participants Service users, National Health Service managers, and clinicians.Results User involvement in the programme was initiated and led by professionals. Professionals determined the areas of service improvement service users could participate in. A wide range of activities were considered “user involvement,” from patient satisfaction surveys to service users delivering peer support. Involvement tended to be most active in the least technical areas and areas with least input from clinicians. Factors that might explain this included organisational structure, the vagueness of the concept of user involvement, the value attributed to service users’ experiential knowledge, and variations in professional and service user understandings of and commitment to involvement. The gains of involvement were harder to identify in terms of impact on services. More evident were the personal gains for those involved: satisfaction of feeling listened to by professionals, social opportunities of meeting others in a similar situation, and increased knowledge about stroke and services available.Conclusions User involvement may not automatically lead to improved service quality. Healthcare professionals and service users understand and practise user involvement in different ways according to individual ideologies, circumstances, and needs. Given the resource implications of undertaking user involvement in service development there is a need for critical debate on the purpose of such involvement as well as better evidence of the benefits claimed for it.  相似文献   
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The gene coding for human anti-Müllerian hormone (AMH) was localized to subbands p13.2----p13.3 on chromosome 19, using in situ hybridization and Southern blot analysis of a panel of man-mouse and man-hamster somatic cell hybrids.  相似文献   
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To examine the effects of prepubertal steroid environment on subsequent estrous cyclicity and gonadotropin secretion, Silastic implants containing 25, 50 or 100% 17 beta-estradiol (E2;n=34), 50% diethylstilbestrol (DES; n=16) or 50% testosterone (T; n=17) were placed into female rats at 12 days of age and removed on the day of vaginal opening (18-24 days of age). At 80 days of age, the percentages of regularly cycling females in the E2-(three groups combined), DES- and T-implanted groups were 59%, 0% and 59%, respectively. By 110 days of age, the percentages were reduced to 24%, 0% and 0%, and at 140 days of age 6%, 0% and 0%, respectively. Many of these females displayed irregular estrous cycles followed by a persistent estrous (PE) state. By contrast, 89% of the control females (blank implants or no implant) maintained regular cycles up to 140 days of age. At 150 days of age, an i.p. injection of gonadotropin-releasing hormone (GnRH; 100 ng/100 g BW) markedly increased serum luteinizing hormone (LH), but not follicle-stimulating hormone (FSH), in intact PE females treated prepubertally with E2 implants. After the test with GnRH, PE rats were ovariectomized (OVX). Thirty days after OVX, similar GnRH administration significantly increased serum levels of both LH and FSH, but these responses were significantly (P less than 0.01) reduced when compared with those in OVX controls. Progesterone administration to estradiol benzoate-primed, acutely (3 days) OVX, or long-term (43 days) OVX-PE females did not increase LH or FSH release. These results indicate that exposure to exogenous estrogen or T prior to puberty precipitates the decline in estrous cyclicity associated with the loss of gonadotropin surge response, presumably due to an alteration in hypothalamic GnRH release.  相似文献   
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Abstract: We describe the relative prevalence and pattern of distribution of osteoarthritis (OA) in the hands of elderly (>15 years) rhesus macaques using clinical, radiographic, and skeletal examinations. In the clinical study the prevalence of nodes was 72% and 16% in the distal inter-phalangeal joints (DIPJ) and proximal inter-phalangeal joints (PIPJ), respectively, 31% of all monkeys had polyarticular nodes. Radiographic OA was present in 55%, 9.1%, and 0% of the DIPJs, PIPJs, and thumb bases, respectively. Skeletal OA as defined by joint surface eburnation for the DIPJ, PIPJ, and thumb base were 16%, 8%, and 2%, respectively. A similar pattern of hand OA with humans is described except for the thumb base OA. This may be due to the relatively rudimentary manipulative role of the macaque thumb. The finding of polyarticular nodal OA raises the possibility of a common pathogenensis for IPJ OA amongst primates.  相似文献   
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Efficient lipid-mediated transfection of DNA into primary rat hepatocytes   总被引:3,自引:0,他引:3  
Cationic lipids are an effective means for transfecting nucleic acids into a variety of cell types. Very few of these lipids, however, have been reported to be effective with primary cells. We report on the efficacy of several commercially available cationic lipid reagents to transfect plasmid DNA into primary rat hepatocytes in culture. The reagents tested in this study include TransfectAce, LipofectAmine, Lipofectin, N-[1-(2,3-dioleyloxy)propyl]-n,n,n-trimethylammoniumchloride (DOTMA), (N-[1-(2,3-dioleoyloxy)propyl]-N,N,N-trimethyl-ammonium methylsulfate (DOTAP), and cetyltrimethyl-ammonium bromide/dioleoylphosphatidylethanol-amine (CTAB/DOPE). Electron micrographic (EM) studies indicate that similar size Lipofectin and DOTAP vesicles contain DNA-like material internally and that these vesicles attach to the cell membrane. DOTAP vesicles are multilamellar, appear as clusters, and have a high DNA-to-lipid ratio. Lipofectin vesicles appear to attach to the cell surface as individual vesicles. The EM observations are consistent with current theories on the mechanism of transfection by cationic lipids. While Lipofectin has proven to be effective in transfection studies of primary cells in culture, we have found DOTAP to be a viable alternative. DOTAP yields transfection rates in hepatocytes comparable to DOTMA and Lipofectin, however, at lower concentrations of reagent and at considerably less cost. Optimal conditions for transfecting 5 μg of plasmid DNA with DOTAP were achieved by utilizing multilamellar (vortexed) vesicles at a concentration of 15 μg DOTAP per 2 ml media in 60-mm plates for 2 h transfection time. In this study, DOTAP has proven to be economical, easy to prepare, and very effective in transfecting DNA into primary rat hepatocytes.  相似文献   
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The mucin-type carbohydrate Tn cryptantigen (GalNAc1-O-Ser/Thr,where GalNAc is N-acetyl-D-galactosamine) is expressed in manycarcinomas, in haemopoietic disorders including the Tn syndrome,and on human immunodeficiency virus (HIV) coat glycoproteins,but is not expressed on normal, differentiated cells becauseof the expression of a Tn-processing galactosyltransferase.Using Jurkat T leukaemic cells which express high levels ofTn antigen due to deficient Tn galactosylation, we have establishedthe Tn antigen-mediated gene transfer and demonstrate the considerableefficiency of this approach. We used poly(L-lysine) conjugatesof the monoclonal antibody 1E3 directed against the Tn antigento deliver the luciferase and ß-galactosidase reportergenes to Jurkat cells by receptor-mediated endocytosis. Additionof unconjugated 1E3 reduced transfection efficiency in a concentration-dependentmanner and incubation with free GalNAc abolished DNA transfercompletely, indicating that gene delivery is indeed mediatedby the Tn antigen. Pre-treatment of Jurkat cells with Vibriocholerae sialidase, which uncovers additional Tn antigens, resultedin an improvement of gene transfection. Both human and chickenadenovirus particles attached to the DNA/polylysine complexstrongly augmented transgene expression. When the ß-galactosidase(lacZ) gene was delivered to Jurkat cells by Tn-mediated endocytosis,up to 60% of the cells were positive in the cytochemical stainusing 5-bromo-4-chloro-3-indolyl-ß-D-galactopyranoside(X-gal) as a chromogenic substrate. The efficiency of the transferrinreceptor-mediated DNA uptake into Jurkat cells was comparativelylow, although these cells were shown to express considerableamounts of transferrin receptor. We show here that a mucin-typecarbohydrate antigen mediates highly efficient DNA uptake byendocytosis into Jurkat T cells. This method represents a 50-foldimprovement of Jurkat cell transfection efficiency over otherphysical gene transfer techniques. Specific gene delivery toprimary cancer cells exhibiting Tn epitopes may especially bedesirable in immunotherapy protocols. adenovirus endocytosis gene transfer T cell Tn antigen  相似文献   
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Summary During a search for novel coding sequences within the human MHC class I region (chromosome 6p21.3), we found an exon (named B30-2) coding for a 166-amino-acid peptide which is very similar to the C-terminal domain of several coding sequences: human 52-kD Sjögren's syndrome nuclear antigen A/Ro (SS-A/Ro) and ret finger protein (RFP), Xenopus nuclear factor 7 (XNF7), and bovine butyrophilin. The first three of these proteins share similarities over the whole length of the molecule whereas butyrophilin is similar in the C-terminal domain. The N-terminal domain of butyrophilin is similar to rat myelin/oligodendrocyte glycoprotein (MOG) and chicken B blood group system (B-G) protein. These domains are components of a new subfamily of the immunoglobulin superfamily (IgSF). Butyrophilin is thus a mosaic protein composed of the MOG/B-G Ig-like domain and the C-terminal domain of 52-kD SS-A/Ro, RFP, and XNF7 (1330-2-like domain). Moreover, in situ hybridization shows that RFP, butyrophilin, and MOG map to the human chromosome 6p2l.3-6p22 region and are thus close to the MHC class I genes. It is therefore possible that the butyrophilin gene is the product of an exon shuffling event which occurred between ancestors of the RFP and MOG genes. To our knowledge, this is the first example of the colocalization of a chimeric gene and its putative progenitors. Finally, regulatory protein T-lymphocyte 1 (Rpt-1) shares similarities with the N-terminal halves of RFP, 52-kD SS-A/Ro, and XNF7, but not with the B30-2-like domain. We show that the ancestral Rpt-l gene evolved by overprinting. Correspondence to: P. Pontarotti  相似文献   
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