全文获取类型
收费全文 | 6696篇 |
免费 | 518篇 |
国内免费 | 12篇 |
专业分类
耳鼻咽喉 | 46篇 |
儿科学 | 211篇 |
妇产科学 | 203篇 |
基础医学 | 1193篇 |
口腔科学 | 110篇 |
临床医学 | 654篇 |
内科学 | 1237篇 |
皮肤病学 | 207篇 |
神经病学 | 865篇 |
特种医学 | 261篇 |
外科学 | 679篇 |
综合类 | 48篇 |
一般理论 | 5篇 |
预防医学 | 422篇 |
眼科学 | 167篇 |
药学 | 424篇 |
中国医学 | 8篇 |
肿瘤学 | 486篇 |
出版年
2024年 | 23篇 |
2023年 | 109篇 |
2022年 | 173篇 |
2021年 | 253篇 |
2020年 | 181篇 |
2019年 | 231篇 |
2018年 | 264篇 |
2017年 | 214篇 |
2016年 | 270篇 |
2015年 | 287篇 |
2014年 | 317篇 |
2013年 | 369篇 |
2012年 | 582篇 |
2011年 | 575篇 |
2010年 | 286篇 |
2009年 | 264篇 |
2008年 | 387篇 |
2007年 | 335篇 |
2006年 | 337篇 |
2005年 | 311篇 |
2004年 | 237篇 |
2003年 | 263篇 |
2002年 | 199篇 |
2001年 | 61篇 |
2000年 | 55篇 |
1999年 | 45篇 |
1998年 | 40篇 |
1997年 | 32篇 |
1996年 | 30篇 |
1995年 | 22篇 |
1994年 | 25篇 |
1993年 | 14篇 |
1992年 | 19篇 |
1991年 | 36篇 |
1990年 | 40篇 |
1989年 | 19篇 |
1988年 | 27篇 |
1987年 | 22篇 |
1986年 | 28篇 |
1985年 | 18篇 |
1984年 | 16篇 |
1983年 | 13篇 |
1982年 | 10篇 |
1981年 | 11篇 |
1980年 | 7篇 |
1979年 | 11篇 |
1977年 | 7篇 |
1974年 | 10篇 |
1972年 | 7篇 |
1937年 | 18篇 |
排序方式: 共有7226条查询结果,搜索用时 15 毫秒
31.
Comparison of modified Bordet-Gengou and modified Regan-Lowe media for the isolation of Bordetella pertussis and Bordetella parapertussis.
下载免费PDF全文
![点击此处可从《Journal of clinical microbiology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
T A Kurzynski D M Boehm J A Rott-Petri R F Schell P E Allison 《Journal of clinical microbiology》1988,26(12):2661-2663
Culture and fluorescent-antibody methods for detection of Bordetella species were evaluated by two state public health laboratories. Field-inoculated plates of Regan-Lowe agar medium were most useful if incubation was initiated on the day of collection. Regan-Lowe and Bordet-Gengou media were comparable for subculturing nasopharyngeal specimens that were transported and enriched in half-strength Regan-Lowe agar. Maximum sensitivity was achieved when the media were used in parallel. Fluorescent-antibody-stained smears of nasopharyngeal specimens were more sensitive for detection of Bordetella pertussis than for detection of Bordetella parapertussis. The fluorescent-antibody method, however, was too insensitive for use without culture. 相似文献
32.
Lee YJ Hohoff C Domschke K Sand P Kuhlenbäumer G Schirmacher A Freitag CM Meyer J Stöber G Franke P Nöthen MM Fritze J Fimmers R Garritsen HS Stögbauer F Deckert J 《Neuroscience letters》2005,377(1):40-43
Several biochemical and pharmacological studies suggest that the catecholaminergic system involving the norepinephrine transporter (NET) is relevant for the pathogenesis of panic disorder. Three single nucleotide polymorphisms in the promoter or untranslated 5' region of the NET gene were investigated by means of RFLP analysis in a sample of 115 German patients with panic disorder and 115 matched controls. Statistical analysis failed to show association with the overall diagnosis of panic disorder. In the subgroup of patients with panic disorder without agoraphobia, however, two polymorphisms were found to be associated with the disease (G/C (rs2397771): p < 0.05; T/C (rs2242446): p < 0.01). While our data do not support a major function of the NET gene in the development of panic disorder, it may play a role in the subgroup of panic disorder without agoraphobia. 相似文献
33.
Gerhold K Blümchen K Bock A Seib C Stock P Kallinich T Löhning M Wahn U Hamelmann E 《The Journal of allergy and clinical immunology》2002,110(1):110-116
BACKGROUND: Contact with immunomodulatory factors, such as LPS, in early infancy is associated with decreased allergen sensitization. OBJECTIVE: We sought to study the effects of systemic or airway exposure with LPS on the development of allergen sensitization, eosinophilic airway inflammation, and increased in vivo airway reactivity (AR) in a mouse model. METHODS: BALB/c mice were systemically sensitized with ovalbumin (OVA) plus adjuvant on days 1 and 14 and challenged through the airways with allergen on days 34 to 36. We performed measurement of OVA-specific IgE serum levels, in vitro T(H)2 cytokine production, differential cell counts in bronchoalveolar lavage fluids, and assessment of in vivo AR to inhaled methacholine by means of barometric whole-body plethysmography. RESULTS: Systemic LPS administration before OVA sensitization reduced OVA-specific IgE serum levels (426 +/- 76 vs 880 +/- 104 U/mL, P <.01), T(H)2 cytokine production by splenic mononuclear cells (IL-4: 0.08 +/- 0.01 vs 0.17 +/- 0.01 ng/mL; IL-5: 1.98 +/- 0.52 vs 4.11 +/- 0.54 ng/mL; P <.01), and extent of airway eosinophilia (total cell counts: 93 vs 376 x 10(3)/mL; eosinophils: 23% vs 51%; P <.01) compared with that in OVA-sensitized mice. Local LPS administration to sensitized mice before airway allergen challenges particularly induced IFN-gamma production by peribronchial lymph node cells in vitro (1718 +/- 315 vs 483 +/- 103 ng/mL, P <.01) associated with reduced airway eosinophilia compared with that seen in OVA-sensitized mice. Development of increased AR was not affected by systemic or local LPS exposure. Inhibitory effects of LPS on allergen sensitization and eosinophilic airway inflammation were inhibited by administration of anti-IL-12 antibodies before LPS exposure. CONCLUSION: These data indicate that local and systemic application of LPS modulates systemic and local T(H)1/T(H)2 immune responses in a distinct but similarly IL-12-dependent mode. 相似文献
34.
35.
The Arabidopsis PILZ group genes encode tubulin-folding cofactor orthologs required for cell division but not cell growth 总被引:5,自引:0,他引:5
Steinborn K Maulbetsch C Priester B Trautmann S Pacher T Geiges B Küttner F Lepiniec L Stierhof YD Schwarz H Jürgens G Mayer U 《Genes & development》2002,16(8):959-971
Plant microtubules are organized into specific cell cycle-dependent arrays that have been implicated in diverse cellular processes, including cell division and organized cell expansion. Mutations in four Arabidopsis genes collectively called the PILZ group result in lethal embryos that consist of one or a few grossly enlarged cells. The mutant embryos lack microtubules but not actin filaments. Whereas the cytokinesis-specific syntaxin KNOLLE is not localized properly, trafficking of the putative auxin efflux carrier PIN1 to the plasma membrane is normal. The four PILZ group genes were isolated by map-based cloning and are shown to encode orthologs of mammalian tubulin-folding cofactors (TFCs) C, D, and E, and associated small G-protein Arl2 that mediate the formation of alpha/beta-tubulin heterodimers in vitro. The TFC C ortholog, PORCINO, was detected in cytosolic protein complexes and did not colocalize with microtubules. Another gene with a related, although weaker, embryo-lethal phenotype, KIESEL, was shown to encode a TFC A ortholog. Our genetic ablation of microtubules shows their requirement in cell division and vesicle trafficking during cytokinesis, whereas cell growth is mediated by microtubule-independent vesicle trafficking to the plasma membrane during interphase. 相似文献
36.
Simona Di Terlizzi Elisabetta Zino Benedetta Mazzi Chiara Magnani Cristina Tresoldi Serena Kimi Perna Marco Bregni Silvano Rossini Fabio Ciceri Claudio Bordignon Chiara Bonini Katharina Fleischhauer 《Biology of blood and marrow transplantation》2006,12(1):95-101
Minor histocompatibility antigens (mHags) HA-1 and HA-2 are encoded by biallelic loci, with immunogenic variants, HA-1H and HA-2V, which induce strong HLA-A2-restricted alloreactive T-cell responses, and nonimmunogenic counterparts, HA-1R and HA-2M, which represent functional null alleles that are poorly presented by HLA class I molecules. HA-1 and HA-2 are potential targets of selective graft-versus-leukemia and graft-versus-tumor reactivity after allogeneic hematopoietic stem cell transplantation (HSCT); however, these applications are restricted to a limited number of patients. Here, we show that a far more frequent application of HA-1 and HA-2 disparity relies on their use as markers for the state of host chimerism after allogeneic HSCT. We have determined allelic frequencies of 29.3% and 70.7% for HA-1H and HA-1R, respectively, and of 83.7% and 16.3% for HA-2V and HA-2M, respectively, in >200 healthy individuals from northern Italy. Similar frequencies were observed in nearly 100 patients affected by hematologic malignancies or solid tumors, thus showing that HA-1 and HA-2 variability are not associated with the presence of cancer. On the basis of these data, we predict that HA-1 and HA-2 can be used in 32.8% and 23.5% of Italian transplant patients, respectively, as markers for the state of host chimerism, whereas exploitation of disparity for these mHags for targeted immunotherapy will be possible in 10.7% and 1.1% of Italian patients, respectively. Retrospective HA-2 typing of bone marrow aspirates obtained from a patient during complete remission or recurrence of acute myeloid leukemia after haploidentical HSCT showed the feasibility of using HA-2 as a surrogate marker for disease monitoring. Because of an apparent north-south gradient for HA-1 allelic frequencies, with higher frequencies for the HA-1H variant reported in white populations from Southern Europe as compared with Northern Europe and North America, the diagnostic applicability of HA-1 disparity will be slightly more frequent in transplant patients from the north. Taken together, our data show that determination of HA-1 and HA-2 variability can be an important parameter for the selection of allogeneic stem cell donors, in particular for patients affected by hematologic malignancies without a tumor-specific molecular marker. 相似文献
37.
Illigens BM Yamada A Fedoseyeva EV Anosova N Boisgerault F Valujskikh A Heeger PS Sayegh MH Boehm B Benichou G 《Human immunology》2002,63(10):912-925
In this study, we measured direct and indirect T-cell alloresponses mediated by CD4(+) and CD8(+) T cells in three mouse transplantation models: skin, cornea, and retina. We show that the contribution of direct and indirect antigen recognition pathways to the alloresponse to fully allogeneic grafts varies depending upon the nature of the tissue/organ transplanted. The implications of this finding for understanding the cellular mechanisms by which rejection is mediated in different transplant models are discussed. 相似文献
38.
Wollmer MA Papassotiropoulos A Streffer JR Grimaldi LM Kapaki E Salani G Paraskevas GP Maddalena A de Quervain D Bieber C Umbricht D Lemke U Bosshardt S Degonda N Henke K Hegi T Jung HH Pasch T Hock C Nitsch RM 《Psychiatric genetics》2002,12(3):155-160
Tissue inhibitor of metalloproteinases 1 (TIMP-1) inhibits several proteinases including a disintegrin and metalloproteinase 10 (ADAM10), a major alpha-secretase that cleaves the beta-amyloid precursor protein within its amyloidogenic Abeta domain. The gene encoding TIMP-1 (TIMP 1) maps to the short arm of the X chromosome, in a region previously suggested as conferring genetic susceptibility for Alzheimer's disease (AD). To determine whether genetic variability of TIMP 1 contributes to the pathogenesis of AD, we analysed one single nucleotide polymorphism within TIMP 1 and one single nucleotide polymorphism in the 5'-untranslated region of TIMP 1 in patients with AD and control subjects from two independent and ethnically different populations. We did not observe any association between TIMP 1 genotypes and the diagnosis of AD in men or women. We also measured TIMP-1 protein levels in the cerebrospinal fluid of patients with AD, healthy control subjects, and patients with other neurological disorders. TIMP-1 levels were similar in all groups. In addition, no significant differences were observed after stratification for TIMP 1 genotypes. Our data show that neither genetic variability nor protein levels of TIMP-1 are associated with AD. 相似文献
39.
Extrinsic risk factors for compromised blood flow in the vertebral artery: anatomical observations of the transverse foramina from C3 to C7 总被引:2,自引:0,他引:2
Cagnie B Barbaix E Vinck E D'Herde K Cambier D 《Surgical and radiologic anatomy : SRA》2005,27(4):312-316
The vertebral artery (VA) is often involved in the occurrence of complications after spinal manipulative therapy. Due to osteophytes
compressing the VA anteriorly from the uncinate process or posteriorly from the facet complex, the VAs are susceptible to
trauma in the transverse foramina. Such altered anatomical configurations are of major clinical significance, as spinal manipulations
may result in dissection of the VA with serious consequences for the blood supply to the vertebrobasilar region. The purpose
of this study is to describe numerous structural features of the third to seventh cervical vertebrae in order to contribute
to the understanding of pathological conditions related to the VA. The minimal and maximal diameter of 111 transverse foramina
in dry cervical vertebrae were studied. The presence of osteophytes and their influence on the VA were evaluated at the vertebral
body and at the superior and inferior articular facets. The diameter of the transverse foramina increased from C3 to C6, while
the transverse foramina of C7 had the smallest diameter. At all levels the mean dimensions of the left foramina were greater
than those of the right side. Osteophytes from the uncinate process of C5 and C6 vertebrae were found in over 60% of dry vertebrae.
Osteophytes from the zygapophyseal joints were more frequent at C3 and C4 vertebrae. About half of the osteophytes of the
uncinate and of the superior articular process partially covered the transverse foramina. This was less common with those
of the inferior articular facets. Osteophytes covering the transverse foramen force the VAs to meander around these obstructions,
causing narrowing through external compression and are potential sites of trauma to the VAs potentially even leading to dissection.
We strongly advocate that screening protocols for vertebrobasilar insufficiency (VBI) be used prior to any manipulation of
the cervical spine and should include not only extension and rotation but any starting position from which the planned manipulation
will be performed. 相似文献
40.
T cell epitope spreading to myelin oligodendrocyte glycoprotein in HLA-DR4 transgenic mice during experimental autoimmune encephalomyelitis 总被引:2,自引:0,他引:2
Klehmet J Shive C Guardia-Wolff R Petersen I Spack EG Boehm BO Weissert R Forsthuber TG 《Clinical immunology (Orlando, Fla.)》2004,111(1):53-60
Epitope spreading has been implicated in the pathogenesis of experimental autoimmune encephalomyelitis (EAE) and human multiple sclerosis (MS). T cell epitope spreading has been demonstrated in rodents for myelin basic protein (MBP) and proteolipid protein (PLP) determinants, but not for myelin oligodendrocyte glycoprotein (MOG), another important myelin antigen. Moreover, the role of human autoimmunity-associated MHC molecules in epitope spreading, including HLA-DR2 and DR4, has not been formally examined. To address these questions, we investigated epitope spreading to MOG determinants in HLA-DR4 (DRB1*0401) transgenic mice during EAE. The data show that upon induction of EAE in HLA-DR4 transgenic mice with the immunodominant HLA-DR4-restricted MOG peptide 97-108 (MOG(97-108); TCFFRDHSYQEE), the T cell response diversifies over time to MOG(181-200) (core: MOG(183-191); FVIVPVLGP) and MBP. The spreading epitope MOG(181-200) binds with high affinity to HLA-DRB1*0401 and is presented by human HLA-DRB1*0401+antigen presenting cells. Moreover, this epitope is encephalitogenic in HLA-DRB1*0401 transgenic mice. This study demonstrates intra- and intermolecular epitope spreading to MOG and MBP in "humanized" HLA-DR4 transgenic mice. 相似文献