全文获取类型
收费全文 | 14043篇 |
免费 | 1145篇 |
国内免费 | 36篇 |
专业分类
耳鼻咽喉 | 99篇 |
儿科学 | 493篇 |
妇产科学 | 303篇 |
基础医学 | 2017篇 |
口腔科学 | 101篇 |
临床医学 | 1891篇 |
内科学 | 2883篇 |
皮肤病学 | 224篇 |
神经病学 | 1406篇 |
特种医学 | 312篇 |
外科学 | 1392篇 |
综合类 | 147篇 |
一般理论 | 20篇 |
预防医学 | 1739篇 |
眼科学 | 165篇 |
药学 | 973篇 |
中国医学 | 16篇 |
肿瘤学 | 1043篇 |
出版年
2024年 | 28篇 |
2023年 | 236篇 |
2022年 | 290篇 |
2021年 | 576篇 |
2020年 | 374篇 |
2019年 | 628篇 |
2018年 | 618篇 |
2017年 | 414篇 |
2016年 | 457篇 |
2015年 | 453篇 |
2014年 | 563篇 |
2013年 | 818篇 |
2012年 | 1223篇 |
2011年 | 1211篇 |
2010年 | 590篇 |
2009年 | 538篇 |
2008年 | 836篇 |
2007年 | 873篇 |
2006年 | 857篇 |
2005年 | 779篇 |
2004年 | 642篇 |
2003年 | 617篇 |
2002年 | 577篇 |
2001年 | 77篇 |
2000年 | 60篇 |
1999年 | 79篇 |
1998年 | 98篇 |
1997年 | 103篇 |
1996年 | 70篇 |
1995年 | 69篇 |
1994年 | 40篇 |
1993年 | 50篇 |
1992年 | 36篇 |
1991年 | 28篇 |
1990年 | 25篇 |
1989年 | 18篇 |
1988年 | 16篇 |
1987年 | 20篇 |
1986年 | 11篇 |
1985年 | 8篇 |
1984年 | 19篇 |
1983年 | 21篇 |
1982年 | 20篇 |
1981年 | 29篇 |
1980年 | 14篇 |
1979年 | 9篇 |
1978年 | 13篇 |
1977年 | 28篇 |
1976年 | 17篇 |
1974年 | 7篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
81.
Held this autumn on the beautiful Cote d'Azur, the first joint meeting of the BSDB and SFBD provided delegates with the perfect informal setting for discussion spanning a broad cross-section of Developmental Biology. Participants' interests were diverse, ranging from the implementation of genome-wide approaches aimed at identifying all the molecular components of cell proliferation, signalling, patterning, and morphogenesis, to those engaged in capturing mesmerising glimpses of the minute and intricate workings of the cell. The meeting considered a wide spectrum of model organisms, including the simple plant Arabidopsis, the invertebrates Dictyostelium, Caenorhabditis elegans, and Drosophila melanogaster, the ascidian Ciona intestinalis, and the vertebrates Xenopus, zebrafish, chick, and mouse. Such a diverse approach served to highlight both similarities and differences in the molecular mechanisms that govern embryonic development among different species. Here, we highlight a few aspects of the meeting that illustrate this point. 相似文献
82.
BACKGROUND: This study sought to extend findings from a preliminary clinical investigation [J. Affect. Disord. 57 (2000) 223] by examining relations between the personality dimension of self-criticism and diagnostic prevalence of social phobia in a large nationally representative sample. METHODS: Participants were from the national comorbidity survey Part II [n=5877; Arch. Gen. Psychiatry 51 (1994) 8]. Psychiatric diagnoses were made using a modified version of the composite international psychiatric interview. Personality dimensions and distress were assessed using brief self-report measures with strong psychometric properties. RESULTS: Self-criticism was elevated in NCS respondents with a diagnosis of social phobia, even in cases of only past history of social phobia (i.e. >1 year ago), compared to individuals with no psychiatric disorder. The highest levels of self-criticism were reported by people with the complex subtype of social phobia, both with and without comorbid major depression. These levels were significantly greater compared to those observed in another anxiety disorder (panic disorder), the pure speaking subtype of social phobia, and cases of major depression alone. In a regression analysis that controlled for current emotional distress, the broad personality trait of neuroticism, and lifetime histories of mood, anxiety, and substance use disorders, self-criticism remained significantly associated with lifetime prevalence of social phobia. LIMITATIONS: The cross-sectional design of the study does not permit causal inferences. CONCLUSIONS: Findings from this general population mental health survey demonstrated that self-criticism is robustly associated with social phobia. It may represent an important core psychological process in the complex subtype of this anxiety disorder. 相似文献
83.
Claire Hivroz Fabienne Mazerolles Mahdhia Soula Rmi Fagard Sophie Graton Sylvain Meloche Rafick P. Sekaly Alain Fischer 《European journal of immunology》1993,23(3):600-607
Human immunodeficiency virus binds to CD4 T lymphocytes by interaction between its envelope glycoprotein gpl20 and the CD4 molecule. The latter is non-covalently associated with a src-related tyrosine kinase, p56lck. CD4 cross-linking increases the activity of p56lck, leading to phosphorylation of several cellular substrates. We report here that gpl60/120 increases both the autophos-phorylation of p56lck and its enzymatic activity (reflected by phosphorylation of an exogeneous substrate) in normal T cells and the HUT78 CD4+ T cell line. This effect was detectable 5 min after activation and persisted for 40 min in normal T cells. It did not require gpl20 cross-linking and was associated with phosphorylation of tyrosine residue on several proteins, as shown by phosphotyrosine Western blot analysis. The pattern of proteins phosphorylated on tyrosine residues in response to gpl20 activation was distinct from that induced by anti-CD4 antibodies. p56lck activation required its association with CD4, since p56lck activity was not modified in HUT78 T cell lines expressing a truncated or mutated form of CD4 unable to associate with p56lck. Peptides mimicking residues 418 to 434 and 449 to 464 of HIV-1 Bru gpl20, regions known to participate in gpl20 binding to CD4, also increased p56lck activity and triggered phosphorylation of similar substrates. Taken together, these results show that gpl60/120 and derived peptides can transiently increase p56lck activity without the need for CD4 cross-linking. This activation led to a specific pattern of tyrosine phosphorylation on cellular proteins that may be of significance in the biological effects of the gpl20/CD4 interaction, e.g. syncytium formation and inhibition of T cell activation. 相似文献
84.
Andrew D Chantry John A Snowden Charles Craddock Karl Peggs Claire Roddie Jenny I O Craig Kim Orchard Keiren E Towlson Rachel M Pearce David I Marks 《Biology of blood and marrow transplantation》2006,12(12):1310-1317
Relapsed acute myeloid leukemia (AML) in adults has a poor prognosis if treated with chemotherapy alone. Case series have previously supported the role of myeloablation and autologous transplantation as a potentially curative treatment. This study aimed to use the large numbers and extended follow-up data in the British Society of Blood and Marrow Transplantation (BSBMT) registry database to establish long-term outcomes and relate these to biological and procedural factors. The BSBMT registry database was used to retrospectively identify 152 adult patients (age, 16-69 years) with AML in second remission treated with autologous transplantation in 1982-2003. Cytogenetic data were available for 68% of the patients; of these, at diagnosis, 42% had good risk features, 57% had standard risk features, and 1% had poor risk features. Conditioning regimens varied; autologous rescue was provided with bone marrow (BM) (71%), peripheral blood stem cells (PBSCs) (18%), or both (11%), which were harvested during first complete remission (CR1) and/or second CR (CR2). Median follow-up was 84 months (range, 2-200 months). At 10 years, actuarial overall survival (OS) was 32%, progression-free survival (PFS) was 28%, and relapse rate (RR) was 57%. The 100-day nonrelapse mortality (NRM) was 7%, rising to 11% at 1 year and to 14% at 10 years. OS was significantly related to M3 subtype (5-year OS, 66%; P = .005), patient age at diagnosis (P = .005) and transplantation (P = .026), and length of CR1, with greatest significance if the patient was dichotomized at CR1 duration of < 8 months or > or = 8 months (P = .0001). There was no difference in OS between regimens containing total body irradiation (TBI) and chemotherapy alone (P = .7). In relation to the nature of autologous graft material, there was improved OS (P = .025) and PFS (P = .009) with the use of cells harvested entirely in CR1 compared with cells harvested in CR2 or in both CR1 and CR2. Engraftment times were significantly shortened with the use of PBSCs alone or in combination with BM compared with BM alone (P = .0001), but there was no significant long-term impact on OS, PFS, RR, or NRM. This study provides long-term follow-up data in one of the largest series of patients with standard-risk and good-risk AML in CR2 treated with autologous transplantation and supports earlier observations that long-term survival is achievable in about 1/3 of patients overall and in about 2/3 of patients with M3 with a relatively low NRM. Outcomes are better in patients with CR1 > or = 8 months by use of grafts obtained entirely in CR1 and use of PBSCs. TBI conditioning did not confer an advantage. Randomized studies against unrelated donor transplantation are warranted. 相似文献
85.
Effect of beta2-glycoprotein I null mutation on reproductive outcome and antiphospholipid antibody-mediated pregnancy pathology in mice 总被引:2,自引:0,他引:2
Robertson SA Roberts CT van Beijering E Pensa K Sheng Y Shi T Krilis SA 《Molecular human reproduction》2004,10(6):409-416
beta(2)-Glycoprotein I (beta(2)GPI) is a principal target antigen for antiphospholipid antibodies associated with recurrent pregnancy loss and fetal growth restriction in women. The significance of disrupted beta(2)GPI activity in contributing to pregnancy pathology in antiphospholipid syndrome (APS) is not clear. In this study the physiological requirement for functional beta(2)GPI in pregnancy was investigated by evaluating reproductive outcomes in beta(2)GPI null mutant (beta(2)GPI-/-) mice. beta(2)GPI-/- mice were fertile and carried viable fetuses to term. However, there was an 18% reduction in the number of viable implantation sites in beta(2)GPI-/- mice and reduced fetal weight and fetal:placental weight ratio in late gestation, suggesting compromised placental function. Placental architecture was altered in beta(2)GPI-/- implantation sites with a 24% increase in the junctional zone: labyrinthine ratio, but placentae showed no evidence of increased thrombosis in the absence of beta(2)GPI. The effect of beta(2)GPI genotype on pregnancy success after passive transfer of human and mouse antibodies reactive with beta(2)GPI was also explored. Two of five anti-beta(2)GPI antibodies induced pregnancy loss in beta(2)GPI+/+ mice but beta(2)GPI-/- mice were refractory to antibody-induced pregnancy failure. We conclude that functional beta(2)GPI is not essential for successful pregnancy in mice, but optimal placental development and fetal growth require this molecule. Together these data are consistent with pathogenic mechanisms in antiphospholipid syndrome involving both neutralization of beta(2)GPI function and beta(2)GPI-immunoglobulin complex formation. 相似文献
86.
Jehane Fadlallah Delphine Sterlin Claire Fieschi Christophe Parizot Karim Dorgham Hela El Kafsi Gaëlle Autaa Pascale Ghillani-Dalbin Catherine Juste Patricia Lepage Marion Malphettes Lionel Galicier David Boutboul Karine Clément Sébastien André Florian Marquet Christophe Tresallet Alexis Mathian Guy Gorochov 《The Journal of allergy and clinical immunology》2019,143(4):1575-1585.e4
87.
Isabelle Garrigue Sébastien Boucher Lionel Couzi Anne Caumont Claire Dromer Martine Neau-Cransac Reza Tabrizi Marie-Hélène Schrive Hervé Fleury Marie-Edith Lafon 《Journal of clinical virology》2006,36(1):72-75
BACKGROUND: Cytomegalovirus (CMV) remains a major opportunistic agent among transplant recipients. While detection of CMV pp65-lower matrix protein (pp65Ag) is still widely used for monitoring CMV infection, real-time PCR assays have been recently developed for routine quantitation of CMV DNA. However, correlations are lacking between results of pp65Ag and quantitative PCR assays and there is no consensus yet as to the more appropriate blood compartment (whole blood (WB), leukocytes, plasma) to be tested with PCR assays. OBJECTIVES: The aims of the study were to determine, in a population of transplant recipients: (i) the correlation between pp65Ag and CMV quantitative real-time PCR in our setting and (ii) the utility of plasma CMV DNA quantitation in comparison to WB quantitation. METHODS: In 170 blood samples (from 61 solid organ or bone marrow transplant recipients) with pp65Ag results, CMV quantitation was performed in WB and plasma using an in-house real-time quantitative PCR. RESULTS: Real-time PCR and pp65Ag results in WB were correlated: thresholds of 10 and 50(+) cells/200,000 cells were equivalent to 3.3 log(10)copies/mL (2,000 copies/mL) and 3.8 log(10)copies/mL (6,300 copies/mL), respectively. When WB viral load was >or=3.6 log(10)copies/mL, the risk to have a negative plasma CMV DNA result was 相似文献
88.
Twenty persons sipped and judged overall perceived magnitude, odor magnitude, and taste magnitude of various concentrations of the odorant citral, the tastants sodium chloride and sucrose, and odorant-tastant combinations. In a second experiment, the same twenty persons sniffed and judged perceived odor magnitude for the same set of stimuli. The investigation probed two primary questions: Does the apparent harmony of an olfactory-taste mixture dictate the degree of additivity in that mixture? Does harmony of the components influence the production of any taste-smell confusion? The data from both the harmonious mixture (citral and sucrose) and the dissonant mixture (citral and NaCl) imply absence of sensory inhibition or facilitation between taste and olfaction. Nevertheless, both types of mixtures led to substantial taste-smell confusion whereby olfactory stimulation evoked sensations of taste. 相似文献
89.
The 2001 Bethesda system (TBS 2001) eliminated the "satisfactory but limited by" category, benign cellular changes (BCC), and the designations "favor benign" (ASC-B) and "favor low grade" (ASC-L) for atypical squamous cells. We compared the unsatisfactory rate and atypical squamous cells:squamous intraepithelial lesions (ASC:SIL) ratio pre- and postimplementation of TBS 2001 to see if there was an increase in unsatisfactory specimens, ASC rate, and altered ASC:SIL ratio. Pap Tests (569,726) reviewed at the Cytopathology Laboratory of Women and Infants Hospital from 1998-2002 were included. TBS 1991 terminology was used through December 31, 2001. Conversion to TBS 2001 took place on January 1, 2002. The average ASC:SIL ratios pre- and postimplementation of TBS 2001 were 1.52:1 and 1.42:1, respectively. The rates of unsatisfactory specimens and ASC remained unchanged. Conversion to TBS 2001 did not adversely affect the ASC:SIL ratio or the detection rates of abnormalities of Pap tests. 相似文献
90.
The effects of intralesion grafts of serotonergic precursors on locomotor recovery and development of chronic pain were assessed after chronic spinal cord hemisection injury (SCI) in rats. Serotonin- and brain-derived neurotrophic factor-secreting (RN46A-B14) and RN46A-vector-only cells were transplanted into the site of T13 lateral hemisection 10 days following injury in immunosuppressed animals, and locomotor and pain related behaviors were assessed weekly for 28 days. There were significant improvements in the degree of spontaneous locomotor recovery, but no significant difference was found in the magnitude of development of mechanical allodynia or thermal hyperalgesia in any transplant group. From these results, we conclude that intraparenchymal engraftment of RN46A-B14 cells is largely ineffective in influencing somatosensory outcomes after SCI, in contrast with the efficacy of dorsal intrathecal placement. 相似文献