全文获取类型
收费全文 | 1584篇 |
免费 | 93篇 |
国内免费 | 8篇 |
专业分类
耳鼻咽喉 | 18篇 |
儿科学 | 77篇 |
妇产科学 | 15篇 |
基础医学 | 150篇 |
口腔科学 | 73篇 |
临床医学 | 196篇 |
内科学 | 432篇 |
皮肤病学 | 18篇 |
神经病学 | 70篇 |
特种医学 | 267篇 |
外科学 | 142篇 |
综合类 | 34篇 |
预防医学 | 46篇 |
眼科学 | 16篇 |
药学 | 66篇 |
中国医学 | 5篇 |
肿瘤学 | 60篇 |
出版年
2023年 | 8篇 |
2021年 | 22篇 |
2020年 | 7篇 |
2019年 | 15篇 |
2018年 | 32篇 |
2017年 | 14篇 |
2016年 | 25篇 |
2015年 | 30篇 |
2014年 | 44篇 |
2013年 | 51篇 |
2012年 | 53篇 |
2011年 | 62篇 |
2010年 | 49篇 |
2009年 | 72篇 |
2008年 | 53篇 |
2007年 | 41篇 |
2006年 | 51篇 |
2005年 | 51篇 |
2004年 | 37篇 |
2003年 | 34篇 |
2002年 | 31篇 |
2001年 | 54篇 |
2000年 | 44篇 |
1999年 | 31篇 |
1998年 | 58篇 |
1997年 | 65篇 |
1996年 | 67篇 |
1995年 | 52篇 |
1994年 | 48篇 |
1993年 | 47篇 |
1992年 | 29篇 |
1991年 | 14篇 |
1990年 | 19篇 |
1989年 | 37篇 |
1988年 | 32篇 |
1987年 | 39篇 |
1986年 | 36篇 |
1985年 | 27篇 |
1984年 | 20篇 |
1983年 | 16篇 |
1982年 | 27篇 |
1981年 | 16篇 |
1980年 | 8篇 |
1979年 | 7篇 |
1978年 | 11篇 |
1977年 | 16篇 |
1976年 | 14篇 |
1975年 | 20篇 |
1974年 | 7篇 |
1971年 | 6篇 |
排序方式: 共有1685条查询结果,搜索用时 328 毫秒
81.
Suk Yun Kang MD PhD Toshiaki Wasaka PhD Ejaz A. Shamim MD Sungyoung Auh PhD Yoshino Ueki MD PhD Grisel J. Lopez MD Tetsuo Kida PhD Seung‐Hyun Jin PhD Nguyet Dang ME Mark Hallett MD 《Movement disorders》2010,25(13):2148-2155
The sequence effect (SE) in Parkinson's disease (PD) is progressive slowing of sequential movements. It is a feature of bradykinesia, but is separate from a general slowness without deterioration over time. It is commonly seen in PD, but its physiology is unclear. We measured general slowness and the SE separately with a computer‐based, modified Purdue pegboard in 11 patients with advanced PD. We conducted a placebo‐controlled, four‐way crossover study to learn whether levodopa and repetitive transcranial magnetic stimulation (rTMS) could improve general slowness or the SE. We also examined the correlation between the SE and clinical fatigue. Levodopa alone and rTMS alone improved general slowness, but rTMS showed no additive effect on levodopa. Levodopa alone, rTMS alone, and their combination did not alleviate the SE. There was no correlation between the SE and fatigue. This study suggests that dopaminergic dysfunction and abnormal motor cortex excitability are not the relevant mechanisms for the SE. Additionally, the SE is not a component of clinical fatigue. Further work is needed to establish the physiology and clinical relevance of the SE. © 2010 Movement Disorder Society. 相似文献
82.
Indium-111 leukocyte scintigraphy in suspected bowel ischemia 总被引:1,自引:0,他引:1
Dhekne RD Chatziioannou SN Moore WH Ford PV Hochman FL 《The American journal of gastroenterology》2000,95(8):1983-1989
OBJECTIVE: The purpose of this study was to evaluate the utility of indium-111 leukocyte (In-111 WBC) scintigraphy in a large number of patients with suspected bowel ischemia. METHODS: All patients who underwent In-111 WBC scintigraphy for possible bowel ischemia over a 4-yr period and had subsequent endoscopic or surgical biopsy were retrospectively evaluated. Early (1-4 h postinjection) and late (18-24 h postinjection) images were obtained. Any study with tracer activity in the bowel on early or late images was considered positive for bowel ischemia. RESULTS: Fifty-nine patients were included in the analysis. In-111 WBC scintigraphy detected 23 of 24 cases of bowel ischemia (sensitivity = 96%). Of 35 cases without ischemia, 16 had a negative In-111 WBC scintiscan (specificity = 46%). Negative and positive predictive values for the diagnosis of bowel ischemia were 94% and 55%, respectively. Of the 19 cases without bowel ischemia and a positive scintiscan, 15 had another intraabdominal process responsible for the patients' symptomatology. CONCLUSIONS: In-111 WBC scintigraphy is a highly sensitive diagnostic tool for bowel ischemia. A normal In-111 WBC scintiscan strongly suggests that this disease is not present. 相似文献
83.
84.
ME Penny 《Acta paediatrica (Oslo, Norway : 1992)》1992,81(S383):114-120
It has been suggested that proliferation of enterobacteriaceae and/or anaerobes in the duodenum of some children with acute diarrhoea determines whether the episode becomes persistent. A review of published studies and the comparison of cultures of duodenal aspirates from Peruvian children with acute and persistent diarrhoea and diarrhoea-free children did not support this hypothesis. Although many children had enterobacteriaceae and/or anaerobes cultured there was no correlation with clinical and nutritional outcome. Age, nutritional status, the environment and the aetiology of the episode were determinants of the duodenal microflora independent of diarrhoea. Culture of the duodenal aspirates did not increase the yield of enteropathogens which were isolated more frequently from stools than from the duodenum. Despite the presence of a single strain or serotype of enterobacteriaceae suggesting that these bacteria were colonizing the duodenum, we were unable to demonstrate any adherence mechanisms in the majority of them. Two often bacteria with no other evidence of virulence caused diarrhoea in the RITARD rabbit model. 相似文献
85.
86.
87.
Pyrrolidine dithiocarbamate protects against thioacetamide-induced fulminant hepatic failure in rats 总被引:3,自引:0,他引:3
Bruck R Aeed H Schey R Matas Z Reifen R Zaiger G Hochman A Avni Y 《Journal of hepatology》2002,36(3):370-377
BACKGROUND/AIMS: Reactive oxygen species and nuclear factor kappa B (NF-kappaB) activation have been implicated in the pathogenesis of cell injury in experimental models of liver damage. The aim of the present study was to examine whether pyrrolidine dithiocarbamate (PDTC), an anti oxidant and inhibitor of NF-kappaB activation, would prevent hepatic damage induced in a rat model of thioacetamide (TAA)-induced liver failure. METHODS: Fulminant hepatic failure was induced in the control and treatment groups by two intraperitoneal injections of TAA (either 300 or 400 mg/kg) at 24-h intervals. In the treatment groups, rats were treated also with PDTC (60 mg/kg/24 h, i.p.), initiated 24 h prior to TAA. RESULTS: Liver enzymes, blood ammonia, and hepatic levels of thiobarbituric acid reactive substances (P<0.001) and protein carbonyls (P<0.05) were significantly lower in rats treated with PDTC compared to TAA only. Liver histology and the survival rate in the PDTC-treated rats were also improved (P<0.01 compared to TAA only). NF-kappaB activation, 2 and 6 h after TAA administration, was inhibited by PDTC. CONCLUSIONS: In a rat model of fulminant hepatic failure, the administration of PDTC attenuated liver damage and improved survival. This effect may be due to decreased oxidative stress and inhibition of NF-kappaB activation. 相似文献
88.
89.
90.