全文获取类型
收费全文 | 2181篇 |
免费 | 220篇 |
国内免费 | 49篇 |
专业分类
耳鼻咽喉 | 14篇 |
儿科学 | 114篇 |
妇产科学 | 105篇 |
基础医学 | 173篇 |
口腔科学 | 61篇 |
临床医学 | 209篇 |
内科学 | 531篇 |
皮肤病学 | 148篇 |
神经病学 | 91篇 |
特种医学 | 250篇 |
外科学 | 198篇 |
综合类 | 130篇 |
预防医学 | 155篇 |
眼科学 | 48篇 |
药学 | 137篇 |
中国医学 | 3篇 |
肿瘤学 | 83篇 |
出版年
2023年 | 18篇 |
2022年 | 15篇 |
2021年 | 40篇 |
2020年 | 35篇 |
2019年 | 24篇 |
2018年 | 42篇 |
2017年 | 55篇 |
2016年 | 55篇 |
2015年 | 51篇 |
2014年 | 88篇 |
2013年 | 93篇 |
2012年 | 54篇 |
2011年 | 64篇 |
2010年 | 81篇 |
2009年 | 103篇 |
2008年 | 62篇 |
2007年 | 107篇 |
2006年 | 71篇 |
2005年 | 64篇 |
2004年 | 73篇 |
2003年 | 63篇 |
2002年 | 46篇 |
2001年 | 55篇 |
2000年 | 44篇 |
1999年 | 52篇 |
1998年 | 93篇 |
1997年 | 68篇 |
1996年 | 64篇 |
1995年 | 59篇 |
1994年 | 56篇 |
1993年 | 46篇 |
1992年 | 38篇 |
1991年 | 29篇 |
1990年 | 42篇 |
1989年 | 41篇 |
1988年 | 51篇 |
1987年 | 45篇 |
1986年 | 54篇 |
1985年 | 37篇 |
1984年 | 26篇 |
1983年 | 23篇 |
1982年 | 19篇 |
1981年 | 14篇 |
1980年 | 18篇 |
1979年 | 11篇 |
1978年 | 18篇 |
1977年 | 27篇 |
1976年 | 14篇 |
1975年 | 15篇 |
1969年 | 8篇 |
排序方式: 共有2450条查询结果,搜索用时 31 毫秒
1.
By injecting small amounts of CO2 through a needle, one can move bowel or bladder from the intended path of instruments during interventional procedures. The technique worked well in six of seven cases in the pelvis and retroperitoneum; it was not effective in the mediastinum or midabdomen (n = 6). 相似文献
2.
Megan A. O’Grady Kristina Wilson Jennifer J. Harman 《The journal of primary prevention》2009,30(6):716-731
The purpose of this study was to evaluate a single-session peer-led safer sex intervention, based on the Information-Motivation-Behavioral
Skills theoretical model, for college students residing in campus residence halls. Participants (N = 108) were assigned to either an hour long control or 5-module intervention session. Compared to the control condition,
the intervention increased participants’ information and women’s subjective norms about preventative behavior. Both the control
and intervention sessions increased intentions to perform preventative behaviors (e.g., keep condoms available). These preliminary
results suggest that this intervention is promising for increasing constructs associated with safer sexual behavior and could
easily be implemented by residence hall staff. 相似文献
3.
J.D. Schold T.R. Srinivas G. Guerra A.I. Reed R.J. Johnson I.D. Weiner R. Oberbauer J.S. Harman A.W. Hemming H.U. Meier-Kriesche 《American journal of transplantation》2007,7(3):550-559
Research suggests that end-stage renal disease patients with elevated body mass index (BMI) have superior outcomes on dialysis. In contrast, low and high BMI patients represent the highest risk cohorts for kidney transplant recipients. The important question remains concerning how to manage transplant candidates given the potentially incommensurate impact of BMI by treatment modality. We conducted a retrospective analysis of waitlisted and transplanted patients in the United States from 1990 to 2003. We constructed Cox models to evaluate the effect of BMI on mortality of waitlisted candidates and identified risk factors for rapid weight change. We then assessed the impact of weight change during waitlisting on transplant outcomes. Decline in BMI on the waiting list was not protective for posttransplant mortality or graft loss across BMI strata. Substantial weight loss pretransplantation was associated with rapid gain posttransplantation. The highest risk for death was among listed patients with low BMI (13-20 kg/m(2), adjusted hazard ratio = 1.47, p < 0.01). Approximately one-third of candidates had a change in BMI category prior to transplantation. While observed declines in BMI may be volitional or markers of disease processes, there is no evidence that candidates have improved transplant outcomes attributable to weight loss. Prospective trials are needed to evaluate the efficacy of weight loss protocols for candidates of kidney transplantation. 相似文献
4.
Partial tolerance in rat renal allograft recipients following multiple blood transfusions and concomitant cyclosporine 总被引:1,自引:0,他引:1
C W Hewitt K S Black J C Harman K R Beko H S Lee A P Patel D C Martin 《Transplantation》1990,49(1):194-198
Multiple prior administrations of donor-strain blood while under limited cyclosporine cover, consistently induce extensive rat renal allograft survival and transplantation tolerance. Yet it was hypothesized that some chronic rejection mechanisms were nevertheless operative since consistent but nonprogressive minor renal dysfunction was observed long-term. A histopathologic study on these putative tolerant rats was undertaken to test this hypothesis. Twenty long-term LEW recipients of BN renal allografts receiving the blood-CsA regimen were examined histopathologically at day 100 post-transplant. Sixteen control LEW recipients receiving only a BN renal allograft were studied acutely at day 7 posttransplant. The control recipients demonstrated a range of lesions consistent with previous studies on acute renal allograft rejection in the rat. However, tolerant recipients demonstrated mild-to-moderate lesions consistent with chronic mechanisms of rejection including the following: moderate focal interstitial mononuclear inflammatory cellular infiltration, with periglomerular and perivascular accumulation; occasional arteriolar luminal obliteration and glomerular atrophy; focal areas of moderate interstitial fibrosis; mild interstitial hemorrhage; mild-to-moderate tubular atrophy; and focal tubular necrosis. Previously our laboratory has documented that tissue-specific renal basement membrane antigens may be responsible for inciting this pattern of focal chronic interstitial inflammation. However, from the present histopathologic studies, it would appear likely that chronic rejection mechanisms in these recipients, which were defined as tolerant by immunologic criteria, involve both tissue-specific and MHC determinants. Therefore, induction of transplantation tolerance in these indefinite survivors is partial or incomplete. 相似文献
5.
6.
外科医生和手术室人员经常接触手术设备产生的烟气,病人也会暴露于烟气中,特别是腹腔镜手术中产生的烟气滞留于腹腔内这一密闭空间并被吸收.这些烟气是一种与香烟烟气相似的毒性物质,然而对这种毒性物质的影响还未引起足够重视.应该采取必要措施尽可能减少手术中烟气的不良影响. 相似文献
7.
8.
A family outbreak of Salmonella enteritidis PT4 infection is described in which home-made ice cream was identified as the vehicle of infection. The ice cream contained approximately 10(5) S. enteritidis PT4 organisms per gm and was probably contaminated by an infected shell egg containing between 10(5)-10(8) organisms. The continued relevance of the Chief Medical Officer''s warning on the use of raw shell eggs is highlighted. Home-made ice cream using the same recipe as ice cream that had been incriminated as the cause of the family outbreak of S. enteritidis PT4 infection was used to study the growth of the organism that might have occurred in the 3-4 h it took to prepare the product. When the inoculum was in the stationary phase, as it would be from shell or other cross contamination, there was a lag phase of 3 h before growth occurred at room temperature. Even when actively multiplying organisms were introduced, as may be found in an infected egg, there was less than 3 log(10) increase in the salmonella count in 4 h at room temperature. It was, therefore, given the high S. enteritidis count, unlikely that the ice cream was cross-contaminated. By contrast, raspberry sorbet at pH 3.73 proved to be lethal to a large inoculum of S. enteritidis and may be a relatively safe raw egg containing product. 相似文献
9.
10.