全文获取类型
收费全文 | 9370篇 |
免费 | 902篇 |
国内免费 | 9篇 |
专业分类
耳鼻咽喉 | 42篇 |
儿科学 | 227篇 |
妇产科学 | 154篇 |
基础医学 | 1193篇 |
口腔科学 | 214篇 |
临床医学 | 1164篇 |
内科学 | 1660篇 |
皮肤病学 | 87篇 |
神经病学 | 654篇 |
特种医学 | 558篇 |
外科学 | 1106篇 |
综合类 | 171篇 |
一般理论 | 4篇 |
预防医学 | 882篇 |
眼科学 | 828篇 |
药学 | 825篇 |
中国医学 | 8篇 |
肿瘤学 | 504篇 |
出版年
2021年 | 116篇 |
2020年 | 91篇 |
2019年 | 146篇 |
2018年 | 144篇 |
2017年 | 114篇 |
2016年 | 143篇 |
2015年 | 155篇 |
2014年 | 222篇 |
2013年 | 347篇 |
2012年 | 425篇 |
2011年 | 391篇 |
2010年 | 263篇 |
2009年 | 221篇 |
2008年 | 448篇 |
2007年 | 448篇 |
2006年 | 406篇 |
2005年 | 421篇 |
2004年 | 395篇 |
2003年 | 329篇 |
2002年 | 320篇 |
2001年 | 288篇 |
2000年 | 322篇 |
1999年 | 253篇 |
1998年 | 133篇 |
1997年 | 140篇 |
1996年 | 131篇 |
1995年 | 134篇 |
1994年 | 125篇 |
1993年 | 96篇 |
1992年 | 237篇 |
1991年 | 202篇 |
1990年 | 198篇 |
1989年 | 185篇 |
1988年 | 189篇 |
1987年 | 182篇 |
1986年 | 168篇 |
1985年 | 186篇 |
1984年 | 135篇 |
1983年 | 108篇 |
1982年 | 86篇 |
1981年 | 60篇 |
1979年 | 87篇 |
1978年 | 83篇 |
1977年 | 79篇 |
1976年 | 72篇 |
1975年 | 57篇 |
1974年 | 69篇 |
1973年 | 63篇 |
1972年 | 58篇 |
1971年 | 56篇 |
排序方式: 共有10000条查询结果,搜索用时 12 毫秒
61.
Turner CK Blieden TM Smith TJ Feldon SE Foster DC Sime PJ Phipps RP 《Journal of immunological methods》2004,291(1-2):63-70
The purpose of this study was to develop an enzyme-linked immunospot assay (ELISpot assay) that can be used with human adherent cells. While standard enzyme-linked immunosorbent assays (ELISAs) are available and widely used and ELISpot assays are used for nonadherent lymphocytes, no ELISpot assay has been developed for adherent cells. We used primary human fibroblasts from four different tissues (myometrium, lung, gingiva, and orbit), either unstimulated or interleukin (IL)-1beta-activated, to evaluate an ELISpot assay. Antibody pairs for IL-6 and IL-8 were used and results were compared to a standard ELISA. We found that we could reliably detect IL-6 and IL-8 spots with as few as 10 fibroblasts. Optimal cell numbers were 50 cells per well incubated for 8 h, although spots appeared as early as 2 h after incubation. Spots were absent when cells, primary, or secondary anti-cytokine antibodies were omitted from the protocol. Spot number and size can be ascertained using current automated ELISpot reader technology. The frequency of IL-6 and IL-8-producing human fibroblasts could also be determined. For example, 60% of the lung fibroblasts express IL-6, but IL-8 can be detected from only 40% of the cells. Approximately 80% of the human orbital fibroblasts make IL-6, whereas approximately 50% generate IL-8 following IL-1beta stimulation. These new findings show that fibroblasts from different human tissues display different frequencies of cytokine production and this further supports the concept of fibroblast diversity. The sensitivity of this new ELISpot assay is adequate for cytokine detection in just a few cells, unlike the standard ELISA. It should permit ascertaining the frequency of fibroblasts and other adherent cells that produce cytokines and, if desired, can be used in tandem with a standard ELISA to determine total cytokine produced. Moreover, the assay is suitable for normal human adherent cells that are often short-lived and difficult to cultivate. 相似文献
62.
Thomas Dörner Sandra J. Foster Hans-Peter Brezinschek Peter E. Lipsky Thomas Dörner Sandra J. Fustcr Hons-Peltr Brtzinschtk Peter E. Lipsky 《Immunological reviews》1998,162(1):161-171
Summary: B cells are unique in that they generate and tolerate a high rate of mutations in their antigen receptor genes and employ these mutations as a basis of avidity maturation. The precise role of the mutational machinery versus subsequent selection in determining the frequency and distribution of mutations has not been fully analyzed. To address these issues, the influence of the intrinsic mutational machinery and subsequent selection on the frequency and distribution of mutations in the expressed human immunoglobulin repertoire was analyzed. Analysis of non-productively rearranged vH genes from individual human B cells provided an opportunity to examine the immediate impact of somatic hypermtitation without superimposed selective influences. Comparison with the frequency and distribution of mutations in the productively rearranged human VH genes permitted an estimate of the influences of subsequent selection. 相似文献
63.
Kenneth Micklethwaite Anna Hansen Aaron Foster Elizabeth Snape Vicki Antonenas Mary Sartor Peter Shaw Ken Bradstock David Gottlieb 《Biology of blood and marrow transplantation》2007,13(6):707-714
Cytomegalovirus reactivation and infection post-allogeneic hematopoietic stem cell transplant continue to cause morbidity and mortality. Current pharmacologic therapies are limited by side effects. Adoptive transfer of ex vivo generated cytomegalovirus-specific T cells has the potential to restore immunity, prevent cytomegalovirus, and circumvent the need for pharmacologic therapies. We have generated donor-derived cytomegalovirus-specific cytotoxic T cells using dendritic cells pulsed with the HLA-A2 restricted nonapeptide NLVPMVATV (NLV) derived from the cytomegalovirus-pp65 protein. These cytotoxic T cells have been given prophylactically to 9 recipients aged 4 to 65 years on or after day 28 post-allogeneic hematopoietic stem cell transplant. Only 2 of 9 recipients received T cell depletion in vivo or in vitro. There were no immediate adverse reactions to the infusions. During 97-798 days of follow-up, 2 recipients developed cytomegalovirus reactivation; neither developed cytomegalovirus disease or required pharmacotherapy. Three recipients developed acute graft versus host disease after infusion. Two recipients died, 1 from thrombotic thrombocytopenia purpura secondary to cyclosporine, 1 from complications of graft versus host disease. A transient increase in numbers of cytomegalovirus-specific T cells demonstrated by NLV-tetramer binding was seen in 6 recipients. Prophylactic adoptive transfer of NLV-specific T cells is safe and may be effective in preventing cytomegalovirus reactivation. 相似文献
64.
Monoclonal antibody LICR-LON-M18 is a marker of normal human breast epithelial cell differentiation. The epitope recognized by LICR-LON-M18 is a prominent component of luminal plasma membranes of nonneoplastic resting and lactating human breast epithelial cells but is rarely expressed by human breast carcinomas. With the use of competitive binding-inhibition studies, the immunodominant portion of the LICR-LON-M18 epitope was shown to be the following oligosaccharide sequence [with galactose (Gal) and N-acetylglucosamine (GlcNAc)]: Gal beta 1----4GlcNAc beta 1----. This structure was distinct from Gal beta 1----3GalNac, which was bound by peanut agglutinin (PNA) and was not recognized by LICR-LON-M18 [corrected]. With the use of biochemical techniques, the present data not only confirmed sialylation and consequent "masking" of the LICR-LON-M18 epitope and PNA determinants in human breast carcinomas but also identified the particular groups of glycoproteins involved in this process. These studies provided additional support for the thesis that sialylation of human breast carcinoma glycoproteins represented an enhancement of specific differentiation events normally regulated in the morphogenesis of nonneoplastic human breast epithelium and that specific glycoproteins became masked during the genesis of primary human breast cancer. 相似文献
65.
Conventional management of acute left sided colonic obstruction employs some form of proximal colostomy. Intraoperative antegrade colonic irrigation relieves proximal faecal loading and may permit safer primary resection and anastomosis. The results of a pilot study are presented, and are shown to be favourable.
on p.56
Full text
Full text is available as a scanned copy of the original print version. Get a printable copy (PDF file) of the complete article (1.4M), or click on a page image below to browse page by page.
5657Images in this article
Figure 1.on p.56
Click on the image to see a larger version.
相似文献66.
67.
Tammy Ju MD Deshka Foster MD PhD Ashley Titan MD Saleh Najjar MD Gregory R. Bean MD PhD Kristen Ganjoo MD Irene Wapnir MD 《The breast journal》2021,27(9):723-725
Radiation-induced breast angiosarcoma, or secondary angiosarcoma (SAS), is a rare entity with a high risk of metastatic recurrence. Herein, we describe the use of intraoperative fluorescence-based skin angiography to guide surgical resection following a novel immunotherapy-based regimen for SAS resulting in a complete pathological response. 相似文献
68.
James F. Markmann Michael R. Rickels Thomas L. Eggerman Nancy D. Bridges David E. Lafontant Julie Qidwai Eric Foster William R. Clarke Malek Kamoun Rodolfo Alejandro Melena D. Bellin Kathryn Chaloner Christine W. Czarniecki Julia S. Goldstein Bernhard J. Hering Lawrence G. Hunsicker Dixon B. Kaufman Olle Korsgren Christian P. Larsen Xunrong Luo Ali Naji José Oberholzer Andrew M. Posselt Camillo Ricordi Peter A. Senior A. M. James Shapiro Peter G. Stock Nicole A. Turgeon 《American journal of transplantation》2021,21(4):1477-1492
69.
Cellular pathology changes in rat skin following intradermal injection of nerve growth factor: neutrophil-dependent and -independent events 总被引:6,自引:0,他引:6
Nerve growth factor (NGF) regulates the survival and development of specific populations of neurones and is involved in wound healing. A further area of study relating to the role of neurotrophins in the mature animal has concerned the possibility that NGF may be a pivotal mediator of inflammation and pain. It has previously been shown that injection of intradermal NGF can result in a neutrophil-dependent hyperalgesia in the rat. The purpose of the present study was to examine the pathological consequence of NGF injected intradermally into mature rat skin and to examine further the role of neutrophils. Standard histopathology techniques (H & E) were employed to determine inflammatory cell counts. Circulating neutrophils were depleted using an anti-rat neutrophil antiserum and results were compared to treatment with vehicle controls. Saline-pretreated rats exhibited normal circulating neutrophil numbers and the dorsal skin showed a significant increase of neutrophil and macrophages at 3 and 5 h and lymphocytes at 5 h after NGF treatment. By comparison, skin sites from neutrophil-depleted rats did not demonstrate a significant increase in neutrophil and macrophage accumulation after NGF administration. All NGF-treated sites, independent of pretreatment, demonstrated abnormal muscle fibre morphology and proliferation of the muscle sarcolemmal nuclei after NGF injection, indicative of tissue injury. In addition, oedema and some fibroplasia were also noted. Furthermore, fibrin production was increased at 3 and 5 h after NGF administration. It is suggested that NGF has a damaging effect on rat muscle which is independent of accumulating neutrophil and other inflammatory cells. In conclusion, the findings indicate a link between NGF-induced neutrophil and macrophage accumulation, as the increase in dermal macrophages was not observed in neutrophil-depleted rats. The results also suggest that NGF can have a profound effect on rat muscle and that this effect may be related to muscle regeneration. 相似文献
70.
S G Sclan J R Foster B Reisberg E Franssen J Welkowitz 《Psychiatric journal of the University of Ottawa》1990,15(4):221-226
Conventional psychometric measures uniformly yield zero or near zero scores (i.e., "bottom-out") as patients with Alzheimer's disease (AD) progress to the more severe stages of the illness. Consequently, there are no psychometric measures which objectively assess the mental abilities of AD patients with very severe cognitive impairment. We explored the hypothesis that mental function in AD patients with very severe cognitive impairment can be effectively assessed using test measures developed to assess the earliest stage of cognitive development as proposed by Piaget. We also investigated the relationship between decline on these experimental cognitive measures and progressive functional disability in patients with severe cognitive impairment. The results indicate that modified instruments derived from measures developed to assess Piaget's sensorimotor stage of cognitive development provide useful information about the cognitive abilities of very severely impaired AD patients. These modified instruments provide a measure of cognition in these extremely impaired patients that has acceptable validity and demonstrable reliability. 相似文献