全文获取类型
收费全文 | 22312篇 |
免费 | 1297篇 |
国内免费 | 157篇 |
专业分类
耳鼻咽喉 | 239篇 |
儿科学 | 419篇 |
妇产科学 | 360篇 |
基础医学 | 2929篇 |
口腔科学 | 616篇 |
临床医学 | 2210篇 |
内科学 | 4868篇 |
皮肤病学 | 426篇 |
神经病学 | 2773篇 |
特种医学 | 1368篇 |
外科学 | 3225篇 |
综合类 | 114篇 |
一般理论 | 7篇 |
预防医学 | 814篇 |
眼科学 | 462篇 |
药学 | 1400篇 |
中国医学 | 14篇 |
肿瘤学 | 1522篇 |
出版年
2023年 | 166篇 |
2022年 | 358篇 |
2021年 | 625篇 |
2020年 | 378篇 |
2019年 | 465篇 |
2018年 | 577篇 |
2017年 | 487篇 |
2016年 | 610篇 |
2015年 | 695篇 |
2014年 | 887篇 |
2013年 | 1049篇 |
2012年 | 1618篇 |
2011年 | 1654篇 |
2010年 | 1068篇 |
2009年 | 989篇 |
2008年 | 1451篇 |
2007年 | 1564篇 |
2006年 | 1368篇 |
2005年 | 1384篇 |
2004年 | 1303篇 |
2003年 | 1207篇 |
2002年 | 1084篇 |
2001年 | 295篇 |
2000年 | 250篇 |
1999年 | 271篇 |
1998年 | 211篇 |
1997年 | 158篇 |
1996年 | 130篇 |
1995年 | 97篇 |
1994年 | 84篇 |
1993年 | 77篇 |
1992年 | 85篇 |
1991年 | 89篇 |
1990年 | 85篇 |
1989年 | 92篇 |
1988年 | 94篇 |
1987年 | 93篇 |
1986年 | 69篇 |
1985年 | 82篇 |
1984年 | 49篇 |
1983年 | 48篇 |
1982年 | 35篇 |
1980年 | 24篇 |
1979年 | 43篇 |
1978年 | 29篇 |
1977年 | 27篇 |
1974年 | 35篇 |
1973年 | 25篇 |
1972年 | 29篇 |
1971年 | 25篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
52.
Laparoscopic (vs. Open) Live Donor Nephrectomy: A UNOS Database Analysis of Early Graft Function and Survival 总被引:8,自引:0,他引:8
Christoph Troppmann Debra B. Ormond Richard V. Perez 《American journal of transplantation》2003,3(10):1295-1301
The impact of laparoscopic (lap) live donor nephrectomy on early graft function and survival remains controversial. We compared 2734 kidney transplants (tx) from lap donors and 2576 tx from open donors reported to the U.S. United Network for Organ Sharing from 11/1999 to 12/2000. Early function quality (>40 mL urine and/or serum creatinine [creat] decline >25% during the first 24 h post-tx) and delayed function incidence were similar for both groups. Significantly more lap (vs. open) txs, however, had discharge creats greater than 1.4 mg/dL (49.2% vs. 44.9%, p = 0.002) and 2.0 mg/dL (21.8% vs. 19.5%, p = 0.04). But all later creats, early and late rejection, as well as graft survival at 1 year (94.4%, lap tx vs. 94.1%, open tx) were similar for lap and open recipients. Our data suggests that lap nephrectomy is associated with slower early graft function. Rejection rates and short-term graft survival, however, were similar for lap and open graft recipients. Further prospective studies with longer follow up are necessary to assess the potential impact of the laparoscopic procurement mode on early graft function and long-term outcome. 相似文献
53.
Kari T Kivist? Olaf Grisk Ute Hofmann Konrad Meissner Klaus-Uwe M?ritz Christoph Ritter Katja A Arnold Dieter Lutj?ohann Klaus von Bergmann Ingrid Kl?ting Michel Eichelbaum Heyo K Kroemer 《Drug metabolism and disposition》2005,33(11):1593-1596
The aim of this study was to characterize the role of the efflux transporter Mrp2 (Abcc2) in the pharmacokinetics of orally and intravenously administered pravastatin in rats. Eight Mrp2-deficient TR- rats and eight wild-type rats were given an oral dose of 20 mg/kg pravastatin. Four TR- animals and four wild-type animals were studied after intravenous administration of pravastatin (5 mg/kg). The TR(-) rats showed a 6.1-fold higher mean area under the plasma concentration-time curve (AUC) of pravastatin (p < 0.001) after oral administration and a 4.7-fold higher AUC (p < 0.01) after intravenous administration of pravastatin as compared with the wild-type animals. The mean systemic (total) clearance of pravastatin was 4.6-fold higher (39.2 versus 8.50 l/h/kg, p < 0.001) and the mean V 4.3-fold higher (14.1 versus 3.29 l/kg, p < 0.01) in the wild-type rats. The mean renal clearance of pravastatin in the TR(-) rats was 16.5-fold increased as compared with the wild-type animals (0.695 versus 0.042 l/h/kg, p < 0.05). The increased systemic exposure to oral pravastatin in the TR- rats was associated with a greater inhibitory effect on 3-hydroxy-3-methylglutaryl CoA reductase, as shown by smaller lathosterol to cholesterol concentration ratios. These results suggest that the reduced biliary pravastatin excretion in the Mrp2-deficient TR- rats is partly compensated for by increased urinary excretion of pravastatin. Furthermore, intestinal Mrp2 does not appear to play a major role in the oral absorption of pravastatin in normal rats. 相似文献
54.
In 1984 and at the beginning of 1985 the authors carried out radioimmunoassays (SORIN-CIS kit) the plasma levels of ACTH in 116 multiple sclerosis patients (m-52, f-64) and in 10 cases this radioimmunoassay was done in the cerebrospinal fluid (m-5, f-5). The control group comprised 90 patients with ischialgia and neuroses. The normal value in the plasma was from 0 to 80.86 pg/ml, and in the fluid it was from 0 to 77.08 pg/ml. In multiple sclerosis patients the plasma ACTH level was from 0 to 286.9 pg/ml, in the cerebrospinal fluid from 0 to 89 pg/ml. The values of ACTH were significantly higher in multiple sclerosis patients, mainly in males. In the fluid the level of ACTH was significantly higher in the studied patients. No significant differences in ACTH levels were found between males and females with multiple sclerosis, and in the control group this level was higher in females. Raised ACTH level was found mainly in multiple sclerosis with lung duration of the disease (10 years) at the time of exacerbations. The authors continue studies on the axis hypothalamus-hypophysis-adrenals, on various hormones, prostaglandins, beta-endorphin, biochemical markers, cAMP, cCMP, arylosulphatase A and B MBC etc. 相似文献
55.
56.
57.
Nikolaus A Haas Christoph K Camphausen 《Pediatric critical care medicine》2006,7(4):399; author reply 399-399; author reply 400
58.
Anna Gasinska Jan Skolyszewski Tadeusz Popiela Piotr Richter Zbigniew Darasz Krystyna Nowak Joanna Niemiec Beata Biesaga Agnieszka Adamczyk Krzysztof Bucki Krzysztof Malecki Marian Reinfuss Teresa Kowalska 《Journal of gastrointestinal surgery》2007,11(4):520-528
Purpose Assessment of tumor proliferation rate using Bromodeoxyuridine labeling index (BrdUrdLI) as a possible predictor of rectal
cancer response to preoperative radiotherapy (RT).
Methods and material Ninety-two patients were qualified either to short RT (5 Gy/fraction/5 days) and surgery about 1 week after RT (schedule I),
or to short RT and 4–5 weeks interval before surgery (schedule II). Tumor samples were taken twice from each patient: before
RT and at the time of surgery. The samples were incubated with BrdUrd for 1 h at 37°C, and the BrdUrdLI was calculated as
a percentage of BrdUrd-labeled cells.
Results Thirty-eight patients were treated according to schedule I and 54 patients according to schedule II. Mean BrdUrdLI before
RT was 8.5% and its value did not differ between the patients in the two compared groups. After RT tumors showed statistically
significant growth inhibition (reduction of BrdUrdLI). As the pretreatment BrdUrd LI was not predictive for early clinical
and pathologic tumor response, prognostic role of the ratio of BrdUrdLI after to BrdUrdLI before RT was considered. The ratios
were calculated separately for fast (BrdUrd LI > 8.5%) and slowly (BrdUrd LI ≤ 8.5%) proliferating tumors and correlated with
overall treatment time (OTT, i.e., time from the first day of RT to surgery). One month after RT, accelerated proliferation
was observed only in slowly proliferating tumors.
Conclusions Pretreatment BrdUrdLI was not predictive for early clinical and pathologic tumor response. The ratio after/before RT BrdUrdLI
was correlated to inhibition of proliferation in responsive tumors.
The paper was presented at ECCO 13, October 30 to November 03, 2005 in Paris, France 相似文献
59.
Onnen Grauhan Henryk Siniawski Michael Dandel Hans Lehmkuhl Christoph Knosalla Miralem Pasic Yu-Guo Weng Roland Hetzer 《European journal of cardio-thoracic surgery》2007,32(4):634-638
OBJECTIVE: Due to the shortage of donor hearts, the criteria for organ acceptability have been considerably extended and donor grafts with coronary atherosclerosis are among those offered. This study evaluated whether and to what degree pre-existing coronary atherosclerosis may be acceptable. METHODS: A total of 1253 consecutive HTx recipients were investigated retrospectively for donor-transmitted coronary atherosclerosis (DCAS). Donor-transmitted coronary atherosclerosis was defined as focal atherosclerosis with stenosis of at least 50%. Inclusion criteria were absence of pre-HTx angiogram but performance of angiogram or autopsy within 6 months after heart transplantation. Kaplan-Meier analysis and log-rank test were used. RESULTS: Eighty-five out of 1253 (6.8%) cases were excluded, since coronary evaluation was not performed within 6 months (n=45) or hearts had undergone pre-transplant angiography (n=40). In 1086 patients no donor-transmitted coronary atherosclerosis was found (NDCAS group) and in 82 patients (7%) donor-transmitted coronary atherosclerosis was diagnosed by angiography (n=49) or autopsy (n=33). Single-vessel donor-transmitted coronary atherosclerosis was found in 53/82 patients (DCAS1 group) and double- or triple-vessel donor-transmitted coronary atherosclerosis in 26/82 patients (DCAS2/3 group). Three of the 82 patients with donor-transmitted coronary atherosclerosis were excluded since the autopsy report was unclear regarding degree of atherosclerosis. Early after heart transplantation the 30-day mortality in the NDCAS and DCAS1 groups was 12.2% versus 13.2% whereas in the DCAS2/3 group it was 61.5%. Beyond the first year the annual decrease with and without donor-transmitted coronary atherosclerosis (single-vessel disease) is comparable. CONCLUSIONS: Donor screening without coronary angiogram overlooks significant atherosclerotic lesions in a considerable number of cases (7.0%). Therefore, angiographic donor screening should be performed. Donor grafts with single-vessel coronary atherosclerosis may be accepted as marginal hearts; however, in our opinion, revascularisation (CABG, PTCA) should be considered. Grafts with two- or even three-vessel coronary atherosclerosis seem to have a serious risk for early graft failure. Beyond the first year the outcome of healthy grafts and grafts with donor-transmitted coronary atherosclerosis seems to be comparable. 相似文献