全文获取类型
收费全文 | 4586篇 |
免费 | 171篇 |
国内免费 | 73篇 |
专业分类
耳鼻咽喉 | 88篇 |
儿科学 | 102篇 |
妇产科学 | 93篇 |
基础医学 | 654篇 |
口腔科学 | 89篇 |
临床医学 | 426篇 |
内科学 | 1063篇 |
皮肤病学 | 66篇 |
神经病学 | 439篇 |
特种医学 | 337篇 |
外科学 | 407篇 |
综合类 | 48篇 |
预防医学 | 220篇 |
眼科学 | 70篇 |
药学 | 458篇 |
1篇 | |
中国医学 | 1篇 |
肿瘤学 | 268篇 |
出版年
2022年 | 45篇 |
2021年 | 94篇 |
2020年 | 40篇 |
2019年 | 60篇 |
2018年 | 85篇 |
2017年 | 54篇 |
2016年 | 49篇 |
2015年 | 77篇 |
2014年 | 113篇 |
2013年 | 157篇 |
2012年 | 184篇 |
2011年 | 223篇 |
2010年 | 148篇 |
2009年 | 163篇 |
2008年 | 169篇 |
2007年 | 213篇 |
2006年 | 212篇 |
2005年 | 205篇 |
2004年 | 180篇 |
2003年 | 168篇 |
2002年 | 159篇 |
2001年 | 149篇 |
2000年 | 137篇 |
1999年 | 119篇 |
1998年 | 106篇 |
1997年 | 99篇 |
1996年 | 97篇 |
1995年 | 85篇 |
1994年 | 61篇 |
1993年 | 61篇 |
1992年 | 46篇 |
1991年 | 66篇 |
1990年 | 76篇 |
1989年 | 98篇 |
1988年 | 80篇 |
1987年 | 110篇 |
1986年 | 60篇 |
1985年 | 89篇 |
1984年 | 48篇 |
1983年 | 53篇 |
1982年 | 40篇 |
1981年 | 31篇 |
1980年 | 33篇 |
1979年 | 34篇 |
1978年 | 18篇 |
1977年 | 23篇 |
1974年 | 28篇 |
1973年 | 21篇 |
1972年 | 22篇 |
1971年 | 25篇 |
排序方式: 共有4830条查询结果,搜索用时 0 毫秒
51.
For several decades New York City hospitals had been distinguished by their tightly regulated environment, chronically weak finances, high occupancy rates, teaching intensity, dependency on public payers, low managed care penetration, and minimal merger activity. Then in the late 1990s a rapid convergence of forces--the Balanced Budget Act, managed care growth, state deregulation of commercial rates, escalating costs, and plunging hospital occupancy rates--threw the city's hospital industry into turmoil. In this paper we describe this period of turbulent change that has left most of the city's safety-net and small community hospitals near bankruptcy. 相似文献
52.
53.
The quantitative determination of coumarins, flavonoids and chlorogenic acid in the leaves and underground parts of Scopolia carniolica Jacq., S. lurida Dun. and S. sinensis Hemsl. using the RP-HPLC method has been described. 相似文献
54.
55.
Cook MT Morrison RN Wilkinson R Nowak BF Hayball PJ Hayball JD 《Developmental and comparative immunology》2001,25(7):553-559
Detailed immunological studies of the teleosts have been hampered by a lack of antibodies against cell-specific markers. Furthermore, where antibodies have been raised, in many instances they have been found to be species-specific. In comparison, many monoclonal and polyclonal antibodies exist with specificities for mammalian proteins and glycoproteins that effectively differentiate leukocyte sub-populations. In this study, we have tested a panel of 54 commercial antibodies against human and murine cell surface receptors for their ability to bind leukocytes isolated from the peripheral blood of snapper (Pagrus auratus). From this panel, one antibody, A452, which is specific for the intracytoplasmic tail of the epsilon (epsilon) chain of the T cell receptor-associated CD3 complex (CD3epsilon) bound to a subpopulation of peripheral blood leukocytes. Mutually exclusive counterstaining was observed when this antibody was used in conjunction with a monoclonal anti-snapper immunoglobulin antibody. This suggests that A452 may be binding to putative snapper T cells. 相似文献
56.
Aurich-Costa J Vannier A Grégoire E Nowak F Cherif D 《Genes, chromosomes & cancer》2001,30(2):143-160
We have developed an alternative multicolor karyotyping technique based on multiplex fluorescence in situ hybridization (M-FISH) and our own optical device with a specific filter set. The most innovative part of our development is the use of interspersed polymerase chain reaction (IRS-PCR) painting probes that show an R-band pattern simultaneous to the combinatorial labeling. This allows us not only to recognize the origin of chromosomal fragments, but to identify the breakpoints as well. We have used this technique to analyze seven cell lines: four prostate cancer cell lines (CA-HPV-10, LNCaP, DU145, and PC3), and three normal transformed epithelial prostate cell lines (PNT1B, PNT2, and PZ-HPV-7). In order to validate our IRS-PCR multiplex FISH (IPM-FISH) technique and to complement the results, we applied comparative genomic hybridization (CGH) and FISH analysis, showing good correlation with the IPM-FISH results. To date, molecular and cytogenetic studies have identified several chromosomal regions that are altered in human prostate cancer; several candidate genes have been suggested. However, reliable markers for predicting the aggressiveness of early prostate cancer are not yet available. Our results show several common, unbalanced rearrangements in the cell lines. These rearrangements are similar to regions already implicated in prostate cancer, validating these cell lines as a good model system. 相似文献
57.
Immunization of HIV-infected children with varicella vaccine 总被引:4,自引:0,他引:4
Levin MJ Gershon AA Weinberg A Blanchard S Nowak B Palumbo P Chan CY;AIDS Clinical Trials Group Team 《The Journal of pediatrics》2001,139(2):305-310
OBJECTIVE: To determine the safety and immunogenicity of varicella vaccine in children with human immunodeficiency virus (HIV) infection. Children (n = 41) who were mildly affected by HIV (Centers for Disease Control and Prevention stage N1 or A1) and had no history or serum antibody indicative of prior varicella infection were immunized with two doses of live attenuated varicella vaccine. RESULTS: A minority of the vaccine recipients had mild local or systemic reactions. Vaccination had no effect on the clinical stage of HIV or the HIV RNA plasma load. CD4 cell percentage and CD4 cell count were marginally decreased at week 4 after the first vaccination; this effect was no longer present at week 8 after vaccination. Two months after the second dose of vaccine, 60% of vaccine recipients had anti-varicella antibody in their serum, and 83% had a positive lymphocyte proliferation assay response to varicella antigen. CONCLUSION: On the basis of its safety and immunogenicity, varicella vaccine should be considered in the childhood vaccines given to mildly affected HIV-infected children. 相似文献
58.
Nowak AK Chow PK Findlay M 《European journal of cancer (Oxford, England : 1990)》2004,40(10):1474-1484
Hepatocellular carcinoma (HCC) is a common cause of cancer mortality worldwide. Whilst local treatments are useful in selected patients, they are not suitable for many with advanced disease. Here, we review phase II and III trials for systemic therapy of advanced disease, finding no strong evidence that any chemotherapy, hormonal therapy, or immunotherapy regimen trialled to date benefits survival in this setting. Many trials were inadequately powered, single centre, and enrolled highly selected patients. From this review, we cannot recommend any therapeutic approach in these patients outside of a clinical trial setting. Including an untreated control arm in clinical trials in HCC is still justified. Every effort should be made to enroll these patients into adequately powered trials, and promising phase II results must be tested in a multicentre phase III setting, preferably against a placebo control arm. Prevention of hepatitis B and C remains vital to decrease deaths from HCC. 相似文献
59.
60.
A novel mechanism of liver allograft rejection facilitated by antibodies to liver sinusoidal endothelial cells 总被引:3,自引:0,他引:3
Sumitran-Holgersson S Ge X Karrar A Xu B Nava S Broomé U Nowak G Ericzon BG 《Hepatology (Baltimore, Md.)》2004,40(5):1211-1221
Liver sinusoidal endothelial cells (LSECs) may be implicated in the induction of liver allograft rejections. We studied the clinical consequences of LSEC-reactive antibodies and their functional capacity in modulating T-cell responses during acute rejections. Pre- and posttransplant sera and T lymphocytes from 95 liver transplant patients were used in this study. LSECs were isolated from normal healthy liver. Binding of antibodies to LSECs was detected using flow cytometry. To study whether LSEC antibodies facilitated cell-mediated immunity, a mixed cell culture (MCC) assay was used. Cytokines in the supernatants of MCC were measured by enzyme-linked immunosorbent assay. Liver biopsy sections were stained to detect the deposition of immunoglobulins in LSECs during rejections. The 2-year patient survival was 86.3%. A significantly higher number of patients with rejections had LSEC antibodies (35/50; 70%) than those without rejections (8/45; 18%) (P < .0001). Purified fractions of LSEC antibodies induced the expression of the costimulatory molecule CD86 on LSECs. A significantly higher number of patients with LSEC antibodies and rejections had an increased proliferation of T cells and markedly decreased levels of transforming growth factor beta (TGF-beta) in the MCC than those without antibodies and rejections (P < .0001, P < .0001, respectively). Deposition of antibodies in LSECs during rejection episodes was observed in the biopsies of patients with LSEC antibodies but not in those without LSEC antibodies. In conclusion, antibodies to LSECs may facilitate acute liver allograft rejections by down-regulating the immune modulating cytokine TGF-beta and thus up-regulating alloreactive T-cell proliferation. 相似文献