全文获取类型
收费全文 | 4645篇 |
免费 | 418篇 |
国内免费 | 12篇 |
专业分类
耳鼻咽喉 | 76篇 |
儿科学 | 107篇 |
妇产科学 | 140篇 |
基础医学 | 534篇 |
口腔科学 | 93篇 |
临床医学 | 584篇 |
内科学 | 861篇 |
皮肤病学 | 55篇 |
神经病学 | 265篇 |
特种医学 | 269篇 |
外科学 | 608篇 |
综合类 | 162篇 |
一般理论 | 1篇 |
预防医学 | 526篇 |
眼科学 | 35篇 |
药学 | 399篇 |
中国医学 | 19篇 |
肿瘤学 | 341篇 |
出版年
2022年 | 33篇 |
2021年 | 65篇 |
2020年 | 48篇 |
2019年 | 68篇 |
2018年 | 63篇 |
2017年 | 56篇 |
2016年 | 73篇 |
2015年 | 122篇 |
2014年 | 116篇 |
2013年 | 142篇 |
2012年 | 248篇 |
2011年 | 275篇 |
2010年 | 127篇 |
2009年 | 131篇 |
2008年 | 155篇 |
2007年 | 208篇 |
2006年 | 219篇 |
2005年 | 180篇 |
2004年 | 185篇 |
2003年 | 177篇 |
2002年 | 133篇 |
2001年 | 134篇 |
2000年 | 145篇 |
1999年 | 125篇 |
1998年 | 66篇 |
1997年 | 81篇 |
1996年 | 65篇 |
1995年 | 59篇 |
1994年 | 48篇 |
1993年 | 50篇 |
1992年 | 111篇 |
1991年 | 104篇 |
1990年 | 84篇 |
1989年 | 93篇 |
1988年 | 94篇 |
1987年 | 85篇 |
1986年 | 78篇 |
1985年 | 83篇 |
1984年 | 58篇 |
1983年 | 57篇 |
1982年 | 37篇 |
1981年 | 36篇 |
1980年 | 49篇 |
1979年 | 47篇 |
1978年 | 32篇 |
1976年 | 35篇 |
1975年 | 33篇 |
1974年 | 36篇 |
1972年 | 32篇 |
1970年 | 33篇 |
排序方式: 共有5075条查询结果,搜索用时 15 毫秒
41.
John F. Teare Roger W. Peterson Karen Authier Linda Schroeder Daniel L. Daly 《Child & youth care forum》1998,27(2):125-138
The purpose of this study was to examine the correlates of post-shelter maternal family satisfaction in a group of youth who
were reunified with their families following a shelter stay. Findings indicated that higher ratings of family satisfaction
were related to greater maternal problem solving skill and less family conflict. 相似文献
42.
Wagner Costalas J Itzen M Malick J Babb JS Bove B Godwin AK Daly MB 《American journal of medical genetics. Part C, Seminars in medical genetics》2003,(1):11-18
We describe results from a survey designed to assess patterns of communication within families shortly after an individual receives results of BRCA1 and BRCA2 mutation carrier status. Shortly after disclosure of BRCA1 and BRCA2 genetic test results, the proband was contacted by phone to administer the post disclosure survey. Questions asked included whether they had shared their results with their siblings or adult children, if there were difficulties in communicating the test results, and if there was any distress associated with the sharing of results. A total of 162 women who have received results from BRCA1 and BRCA2 genetic testing participated in the survey. The probands shared their results more often with their female than their male relatives (P < 0.001). Probands who had tested positive for a mutation in the BRCA1 or BRCA2 gene shared their results more often with their relatives than did probands who were not carriers (P = 0.002). Probands reported more often that their siblings rather than their adult children had difficulties understanding the results (P = 0.001). The probands who were carriers more often reported having difficulties explaining their results to their relatives (P < 0.001) and their relatives were upset on hearing the result more often than were the relatives of probands who were not carriers (P < 0.001). The probands who were carriers reported more often that they were upset explaining their results to their relatives than did the probands who were not carriers (P < 0.001). Individuals are disclosing their test results to their relatives. Probands who are BRCA1- or BRCA2-positive are more likely to experience difficulty and distress with the communication of their test results to family members. 相似文献
43.
44.
45.
If an individual's gas exchange threshold (GET) is measured on several separate occasions, without a change in aerobic fitness, a random variability will be observed. However, it is not known how much of this variability is biologically determined and how much results from variability in the calibration and measurement processes. The statistical re-sampling technique of Bootstrapping was used to estimate the variability of the GET on a single occasion. This analysis provides the first estimate of the combined contribution of breath-by-breath measurement and calibration processes (6%), to the total between-occasion random variability, leaving biological variability to account for the remainder of the imprecision in the measurement of the GET. 相似文献
46.
The H2-receptor antagonists ranitidine and cimetidine inhibit gastric acid secretion elicited by a test meal in the dog. Ranitidine is approximately 10 times more potent than cimetidine in this respect. 相似文献
47.
Schecter AD Berman AB Yi L Ma H Daly CM Soejima K Rollins BJ Charo IF Taubman MB 《Journal of leukocyte biology》2004,75(6):1079-1085
Monocyte chemoattractant protein-1 (MCP-1, CCL2) is a mediator of inflammation that has been implicated in the pathogenesis of a wide variety of human diseases. CCR2, a heterotrimeric G-coupled receptor, is the only known receptor that functions at physiologic concentrations of MCP-1. Despite the importance of CCR2 in mediating MCP-1 responses, several recent studies have suggested that there may be another functional MCP-1 receptor. Using arterial smooth muscle cells (SMC) from CCR2(-/-) mice, we demonstrate that MCP-1 induces tissue-factor activity at physiologic concentrations. The induction of tissue factor by MCP-1 is blocked by pertussis toxin and 1,2-bis(O-aminophenyl-ethane-ethan)-N,N,N',N'-tetraacetic acid-acetoxymethyl ester, suggesting that signal transduction through the alternative receptor is G(alphai)-coupled and dependent on mobilization of intracellular Ca(2+). MCP-1 induces a time- and concentration-dependent phosphorylation of the mitogen-activated protein kinases p42/44. The induction of tissue factor activity by MCP-1 is blocked by PD98059, an inhibitor of p42/44 activation, but not by SB203580, a selective p38 inhibitor. These data establish that SMC possess an alternative MCP-1 receptor that signals at concentrations of MCP-1 that are similar to those that activate CCR2. This alternative receptor may be important in mediating some of the effects of MCP-1 in atherosclerotic arteries and in other inflammatory processes. 相似文献
48.
Andrew Daly Steven McAfee Bimal Dey Christine Colby Leah Schulte Beow Yeap Robert Sackstein Nancy J Tarbell David Sachs Megan Sykes Thomas R Spitzer 《Biology of blood and marrow transplantation》2003,9(6):373-382
Infections are a common complication of allogeneic bone marrow transplantation and the leading cause of transplantation-related mortality. It had been hypothesized that transplantation following nonmyeloablative preparative regimens would result in fewer infections by causing less mucosal injury, less graft-versus-host disease, and allowing earlier immune reconstitution. We have retrospectively reviewed the infectious complications of 65 consecutive patients with advanced hematologic malignancies who underwent bone marrow transplantation using a novel preparative regimen consisting of cyclophosphamide, thymic irradiation, and in vivo T-cell depletion. Cytomegalovirus (CMV) infection occurred in 52% of cases in which the donor or recipient had evidence of prior CMV exposure. Using a strategy of preemptive therapy and secondary prophylaxis with ganciclovir, no CMV disease occurred. Infections with gram-positive bacteria predominated over the first 100 days after bone marrow transplantation. Thereafter, the relative proportion of gram-negative infections increased without a significant increase in episodes of neutropenia. The rate of bacterial infections was not influenced by relapse of the underlying malignancy. Seven patients developed infections with Aspergillus species, which was the most common infectious cause of death in these patients. Infections with viruses other than CMV (n=10) and with protozoan organisms (n=2) also occurred. The use of HLA-mismatched donors, the occurrence of grade II-IV acute graft-versus-host disease, and treatment with corticosteroids did not influence the risk of CMV or bacterial or fungal infections in patients who underwent transplantation following this preparative regimen. Overall, the incidence and spectrum of infections in this series was similar to the reported incidence of infections following conventional myeloablative allogeneic stem cell transplantation. We conclude that a quantitative T-cell deficiency in these extensively T-cell depleted patients may be a risk factor for infection, even in the absence of graft-versus-host disease. 相似文献
49.
Comparison of sorbitol MacConkey agar and a two-step method which utilizes enzyme-linked immunosorbent assay toxin testing and a chromogenic agar to detect and isolate enterohemorrhagic Escherichia coli 总被引:2,自引:0,他引:2
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)
Enterohemorrhagic Escherichia coli (EHEC) and specifically serotype O157:H7 are a significant cause of hemorrhagic gastrointestinal disease and the hemolytic uremic syndrome. Methods currently used in clinical microbiology labs, such as sorbitol-MacConkey (SMAC) agar, reliably detect only O157:H7. We have evaluated a two-step method that has the potential to identify and isolate all EHEC serotypes, including serotype O157:H7. This method utilizes a chromogenic selective-differential medium for the isolation of E. coli together with an enzyme-linked immunosorbent assay (ELISA) that detects the Shiga-like toxins Stx1 and Stx2. Both are commercially available and usable in a wide range of clinical microbiology laboratories. Compared to a Vero cell cytotoxic assay, SMAC had sensitivities of 23.5% for the identification of all EHEC serotypes and of 50.0% for the identification of O157:H7 alone. The two-step method had sensitivities of 76.5 and 100%, respectively. The ELISA alone had a sensitivity of 82.4% in the detection of Stx1 and Stx2. The specificity was 100% in all cases. Overall, 14 EHEC isolates were obtained: 8 (58%) O157:H7, 2 (14%) O26, 2 (14%) O111:NM, 1 (7%) O103:H2, and 1 (7%) O121:H19. All but one were isolated during the months of May to September. The two-step method was found to be considerably more expensive than SMAC for both positive and negative samples. 相似文献
50.