全文获取类型
收费全文 | 242478篇 |
免费 | 16273篇 |
国内免费 | 1474篇 |
专业分类
耳鼻咽喉 | 2465篇 |
儿科学 | 6673篇 |
妇产科学 | 5001篇 |
基础医学 | 32668篇 |
口腔科学 | 5535篇 |
临床医学 | 21945篇 |
内科学 | 52563篇 |
皮肤病学 | 4774篇 |
神经病学 | 23080篇 |
特种医学 | 9651篇 |
外国民族医学 | 29篇 |
外科学 | 35785篇 |
综合类 | 3529篇 |
现状与发展 | 2篇 |
一般理论 | 185篇 |
预防医学 | 16217篇 |
眼科学 | 4621篇 |
药学 | 17891篇 |
3篇 | |
中国医学 | 750篇 |
肿瘤学 | 16858篇 |
出版年
2023年 | 1072篇 |
2022年 | 1712篇 |
2021年 | 4443篇 |
2020年 | 2995篇 |
2019年 | 4303篇 |
2018年 | 5290篇 |
2017年 | 4090篇 |
2016年 | 4526篇 |
2015年 | 5261篇 |
2014年 | 7341篇 |
2013年 | 10198篇 |
2012年 | 15010篇 |
2011年 | 15844篇 |
2010年 | 9434篇 |
2009年 | 8724篇 |
2008年 | 14362篇 |
2007年 | 15211篇 |
2006年 | 14501篇 |
2005年 | 14554篇 |
2004年 | 14283篇 |
2003年 | 13671篇 |
2002年 | 13140篇 |
2001年 | 5154篇 |
2000年 | 4739篇 |
1999年 | 4516篇 |
1998年 | 3203篇 |
1997年 | 2495篇 |
1996年 | 2205篇 |
1995年 | 2050篇 |
1994年 | 1802篇 |
1993年 | 1754篇 |
1992年 | 2533篇 |
1991年 | 2525篇 |
1990年 | 2085篇 |
1989年 | 2021篇 |
1988年 | 1870篇 |
1987年 | 1740篇 |
1986年 | 1665篇 |
1985年 | 1561篇 |
1984年 | 1395篇 |
1983年 | 1253篇 |
1982年 | 1197篇 |
1981年 | 1081篇 |
1980年 | 949篇 |
1979年 | 928篇 |
1978年 | 788篇 |
1977年 | 768篇 |
1975年 | 717篇 |
1974年 | 729篇 |
1973年 | 684篇 |
排序方式: 共有10000条查询结果,搜索用时 78 毫秒
981.
Peter Regitnig Ferdinand Ploner Martina Maderbacher Sigurd F Lax 《Modern pathology》2004,17(5):597-602
Local recurrence of bilateral breast carcinomas is rare, but of biological interest, since it is unclear as to which tumor the local recurrence is related to, the ipsilateral or the contralateral, or whether it is an independent neoplasm. The aim of this study was to investigate the genetic relationship of bilateral breast carcinomas to each other and to their local recurrences. Eight cases of bilateral breast carcinomas, five with and three without local recurrence were analyzed using a microsatellite assay for 13 microsatellite loci. The presence of loss of heterozygosity and microsatellite instability in the various tumors was used for clonal analysis. All eight bilateral breast carcinomas showed divergent alterations in at least two microsatellite loci, which ruled out a genetic relationship. Four of five local recurrences were genetically related to the ipsilateral tumor and unrelated to the contralateral tumor. Only one local recurrence that occurred 11.8 years after the surgery of an infiltrative lobular carcinoma simultaneously with distant metastases was genetically related to the contralateral breast carcinoma. Although the number of cases in our study is limited, there is evidence that local recurrence of bilateral breast carcinoma frequently arises from the ipsilateral tumor. 相似文献
982.
Christine N Vidal Rob Nicolson Timothy J DeVito Kiralee M Hayashi Jennifer A Geaga Dick J Drost Peter C Williamson Nagalingam Rajakumar Yihong Sui Rebecca A Dutton Arthur W Toga Paul M Thompson 《Neuropsychopharmacology》2006,60(3):218-225
BACKGROUND: Volumetric studies have reported reductions in the size of the corpus callosum (CC) in autism, but the callosal regions contributing to this deficit have differed among studies. In this study, a computational method was used to detect and map the spatial pattern of CC abnormalities in male patients with autism. METHODS: Twenty-four boys with autism (aged 10.0 +/- 3.3 years) and 26 control boys (aged 11.0 +/- 2.5 years) underwent a magnetic resonance imaging (MRI) scan at 3 Tesla. Total and regional areas of the CC were determined using traditional morphometric methods. Three-dimensional (3D) surface models of the CC were also created from the MRI scans. Statistical maps were created to visualize morphologic variability of the CC and to localize regions of callosal thinning in autism. RESULTS: Traditional morphometric methods detected a significant reduction in the total callosal area and in the anterior third of the CC in patients with autism; however, 3D maps revealed significant reductions in both the splenium and genu of the CC in patients. CONCLUSIONS: Statistical maps of the CC revealed callosal deficits in autism with greater precision than traditional morphometric methods. These abnormalities suggest aberrant connections between cortical regions, which is consistent with the hypothesis of abnormal cortical connectivity in autism. 相似文献
983.
Camiel De Bruijn Rob de Bie Jacques Geraets Marielle Goossens Wim van den Heuvel Geert van der Heijden Math Candel Geert-Jan Dinant 《BMC musculoskeletal disorders》2007,8(1):112
Background
The education and activation programme (EAP) aims at coping with psychosocial determinants to prevent the development of chronic shoulder complaints (SCs). The effect of the EAP on functional limitations and patient-perceived recovery after 6 and 26 weeks is evaluated in a randomised clinical trial. 相似文献984.
Cristina Martins Marcelo Mazza do Nascimento Roberto Pecoits-Filho Cyntia Leinig Luiz Felipe Gon?alves Roseana Fuerbringer Peter Stenvinkel Bengt Lindholm Miguel Carlos Riella 《Journal of renal nutrition》2007,17(2):132-137
BACKGROUND: Insulin resistance (IR) and inflammation are associated with increased risk of cardiovascular disease in the general population. Continuous glucose absorption in peritoneal dialysis (PD) may induce hyperglycemia and hyperinsulinemia. METHODS: We evaluated IR in nondiabetic patients receiving PD, and analyzed the association between IR and systemic inflammation biomarkers by performing a cross-sectional study on ambulatory dialysis. A total of 25 nondiabetic patients receiving PD and 25 healthy individuals, matched for gender, age, and body mass index (BMI), were included. The PD group was composed of 11 men and 14 women, with a mean age of 47 +/- 14 years and mean BMI of 25.5 +/- 4.7 kg/m(2). The control group was composed of 10 men and 15 women, with a mean age of 45 +/- 12 years and BMI of 24.0 +/- 2.8 kg/m(2). RESULTS: IR was evaluated by the homeostasis model assessment method (HOMA-IR). Inflammation was assessed through high-sensitivity C-reactive protein (CRP) and fibrinogen. Body composition and truncal fat were evaluated by dual energy x-ray absorptiometry. HOMA-IR was significantly higher (P < .0001) in subjects receiving PD (4.9, range: 2.3-9.3 mmol/L x muU/mL) compared with healthy subjects (1.2, range: 0.4-4.8 mmol/L x muU/mL). As expected, compared with controls, patients receiving PD had significantly higher levels of insulin (26.5 +/- 7.5 muU/mL vs 6.3 +/- 3.4 muU/mL; P < .0001), CRP (6.3, range: 0.3-61.1 mg/L vs 2.4, range: 0.6-5.9 mg/L; P = .001), and fibrinogen (379 +/- 101 mg/dL vs 268 +/- 66 mg/dL; P < .0001). However, there were no significant differences in body and truncal fat mass between the groups. A significant correlation between HOMA-IR and fibrinogen (Rho = 0.48; P = .01) was observed. However, no correlation was found between HOMA-IR and CRP. Also, no significant correlations were found between HOMA-IR and body fat mass (Rho = 0.11), and between HOMA-IR and truncal fat mass (Rho = 0.19). CONCLUSIONS: Patients receiving PD demonstrate a state of IR that is associated with high circulating levels of fibrinogen. This suggests that hyperfibrinogenemia may be involved in the pathogenesis of IR in this setting. 相似文献
985.
Cystic fibrosis has evolved from an illness where children died in their teens to one with a longer life expectancy into adult life. Patients now usually keep themselves in a good physical condition, which gives them an opportunity to live a relatively ‘normal’ life. There is a catch: a patient can only achieve this by adhering to a strict, complex and time-consuming therapeutic schedule, thereby introducing an abnormal element into a ‘normal’ life.In this paper we discuss the issue of balancing ‘being ill’ with ‘living like healthy children’, and argue that ‘normality’ is as crucial in any developing CF child as the ‘permission’ to be ill. An important question arises as a consequence of the major improvements in CF care, namely—‘Should all care be done at home or are there advantages in doing part of it in hospital or clinic?’ We contend that this is where the balance lies as there are advantages for some care to continue to be done in hospital. 相似文献
986.
987.
Markus Golling Cosima Jahnke Hamidreza Fonouni Rezvan Ahmadi Renate Urbaschek Raoul Breitkreutz Peter Schemmer Thomas W Kraus Martha M Gebhard Markus W Büchler Arianeb Mehrabi 《Liver transplantation》2007,13(4):607-617
The liver function and perfusion following brain death is mainly influenced by the sympathetic nerves and hormones. We examined the specific influence of surgical liver denervation on systemic and hepatic perfusion parameters, bowel ischemia and oxidative stress in hemodynamically stable BD and control (living donor [LD]) pigs. Brain death was induced in 8 pigs via saline infusion into the balloon of an epidural Tieman-catheter (1 mL/15 minutes) and compared to the control group (n = 6) over 4 hours. At 2 hours postoperatively, complete liver denervation was initiated. We analyzed systemic cardiocirculatory parameters (mean arterial pressure, aortic flow, bowel ischemia (endotoxin, and endotoxin-neutralizing capacity) and oxidative stress (total glutathione in erythrocytes [tGSH(E)]) and compared them to local/hepatic perfusion parameters (hepatic artery and portal venous flow, liver blood flow index, and microperfusion), local bowel ischemia (intramucosal pH [pHi] of stomach [pHi(S)]/colon[pHi(C)]), and liver oxidative stress (glutathione [rGSH(L), GSSG(L)]). Following brain death, the parameters including mean arterial pressure, aortic flow, pHi, endotoxin, and tGSH(E) showed no significant changes at 2 hours. Portal venous flow and microperfusion were decreased significantly and hepatic arterial buffer response was ineffective. Hepatic oxidative stress was increased in BD animals (decrease rGSH(L), increase GSSG(L)). Surgical denervation/manipulation increased portal venous flow significantly, hepatic arterial buffer response became effective, and stomach pHi decreased (BD and LD groups). Hepatic oxidative stress was reduced in the BD group (increase rGSH(L)/GSSG(L); P < 0.001) while it was increased in the LD group (decrease rGSH(L)/GSSG(L); P < 0.001). In conclusion, denervation reduces hepatic oxidative stress in BD only in contrast to the LD. The reciprocal effect of denervation depends on the state of neural activation and postulates a potential benefit of surgical denervation before organ harvesting in brain death. 相似文献
988.
989.
990.