全文获取类型
收费全文 | 7994篇 |
免费 | 308篇 |
国内免费 | 69篇 |
专业分类
耳鼻咽喉 | 26篇 |
儿科学 | 188篇 |
妇产科学 | 127篇 |
基础医学 | 1066篇 |
口腔科学 | 155篇 |
临床医学 | 546篇 |
内科学 | 2149篇 |
皮肤病学 | 217篇 |
神经病学 | 366篇 |
特种医学 | 286篇 |
外科学 | 1284篇 |
综合类 | 40篇 |
一般理论 | 3篇 |
预防医学 | 240篇 |
眼科学 | 106篇 |
药学 | 582篇 |
中国医学 | 66篇 |
肿瘤学 | 924篇 |
出版年
2023年 | 44篇 |
2022年 | 111篇 |
2021年 | 187篇 |
2020年 | 78篇 |
2019年 | 117篇 |
2018年 | 144篇 |
2017年 | 107篇 |
2016年 | 141篇 |
2015年 | 143篇 |
2014年 | 192篇 |
2013年 | 250篇 |
2012年 | 409篇 |
2011年 | 402篇 |
2010年 | 279篇 |
2009年 | 243篇 |
2008年 | 448篇 |
2007年 | 460篇 |
2006年 | 457篇 |
2005年 | 481篇 |
2004年 | 427篇 |
2003年 | 497篇 |
2002年 | 516篇 |
2001年 | 163篇 |
2000年 | 148篇 |
1999年 | 196篇 |
1998年 | 156篇 |
1997年 | 103篇 |
1996年 | 94篇 |
1995年 | 74篇 |
1994年 | 72篇 |
1993年 | 87篇 |
1992年 | 118篇 |
1991年 | 114篇 |
1990年 | 110篇 |
1989年 | 79篇 |
1988年 | 82篇 |
1987年 | 77篇 |
1986年 | 84篇 |
1985年 | 57篇 |
1984年 | 45篇 |
1983年 | 34篇 |
1982年 | 29篇 |
1981年 | 25篇 |
1980年 | 26篇 |
1979年 | 22篇 |
1975年 | 24篇 |
1974年 | 26篇 |
1973年 | 22篇 |
1971年 | 23篇 |
1970年 | 29篇 |
排序方式: 共有8371条查询结果,搜索用时 15 毫秒
181.
Yoshiaki Urabe Kazuhiro Nouso Toshihiro Higashi Harushige Nakatsukasa Naoki Hino Kouzou Ashida Nobuyuki Kinugasa Keigo Yoshida Shuji Uematsu Takao Tsuji 《Liver international》1996,16(5):293-297
Abstract: To determine the role of telomere-mediated gene stability in hepatocarcinogenesis, we examined the telomere length of human liver with or without chronic liver diseases and hepatocellular carcinomas (HCC). The mean telomere restriction fragment (TRF) length of normal liver (n=13), chronic hepatitis (n=11), liver cirrhosis (n=24) and HCC (n=24) was 7.8±0.2, 7.1±0.3, 6.4±0.2 and 5.2±0.2 kb, respectively (mean±standard error). TRF length decreased with a progression of chronic liver diseases and that in HCC was significantly shorter than that in other chronic liver diseases (p<0.05). The ratios of TRF length of HCC to that of corresponding surrounding liver of well differentiated (n=7), moderately differentiated (n=10) and poorly differentiated (n=4) HCCs were 0.83±0.06, 0.75±0.05 and 0.98±0.09, respectively. The ratio of poorly differentiated HCC was significantly higher than that of moderately differentiated HCC (p<0.05). A comparison between the size and telomere length ratio of moderately differentiated HCCs revealed a decrease of the ratio with size until it reached 50 mm in diameter. In contrast, the ratio increased as the size enlarged over 50 mm. These findings suggest that the gene stability of the liver cells mediated by the telomere is reduced as chronic liver disease progresses and that telomerase is activated in poorly differentiated HCC and moderately differentiated HCC over 50 mm in diameter. 相似文献
182.
Expression of recombination activating genes 1 and 2 in peripheral B cells of patients with systemic lupus erythematosus 总被引:1,自引:0,他引:1
OBJECTIVE: To analyze immunoregulatory abnormalities in patients with systemic lupus erythematosus (SLE) by assessing the expression of messenger RNA (mRNA) for types 1 and 2 recombination activating genes (RAG) in the peripheral blood of patients with active SLE. METHODS: We examined B cell populations and also individual B cells from patients with SLE for the expression of RAG mRNA. RESULTS: Analysis of bulk mRNA indicated that RAG1 and RAG2 mRNA were found routinely in peripheral B cells of patients with active SLE, but not in healthy subjects. When assessed on a single-cell basis, there was a 3-fold increase in the frequency of RAG1- and RAG2-expressing B cells in SLE patients compared with healthy subjects. Notably, B cells expressing both RAG1 and RAG2 mRNA expressed only IgD mRNA, but not IgG mRNA. Fifty percent of RAG-expressing B cells also expressed VpreB mRNA, whereas all expressed CD154 mRNA. Phenotypic analysis indicated that RAG-expressing B cells were activated, mature B cells. CONCLUSION: These results indicate that RAG expression is up-regulated in peripheral IgD+ and VpreB+ B cells of patients with active SLE. These cells may contribute to the immunoregulatory abnormalities in patients with SLE. 相似文献
183.
The effect of insulin sensitizer, troglitazone, on lipoprotein lipase mass in preheparin serum 总被引:6,自引:0,他引:6
Shirai K Itoh Y Sasaki H Totsuka M Murano T Watanabe H Miyashita Y 《Diabetes research and clinical practice》1999,46(1):35-41
Lipoprotein lipase mass exists in preheparin serum, even though the activity is scarcely found. The implication of this is unclear. We studied the effect of an insulin sensitizer, troglitazone, on this preheparin serum lipoprotein lipase mass (preheparin LPL mass) in non-insulin-dependent diabetes mellitus (NIDDM) patients as well as on serum lipid levels and low density lipoproteins (LDL) particle size. Thirty-one NIDDM patients with poor control were administered troglitazone 400 mg/day. Hemoglobin A1c had significantly decreased (13%, P < 0.001) 2 months later. Preheparin LPL mass had gradually increased and a 69% increase (P<0.01) was observed 4 months later. Triglyceride significantly decreased (23%, P < 0.01) and high density lipoprotein-cholesterol increased (10%, P < 0.01), whereas total cholesterol and LDL levels did not change 4 months later. The size of LDL increased significantly (P < 0.01). These results were consistent with the idea that preheparin LPL mass might be relating to the insulin sensitivity enhanced by troglitazone, as well as LDL particle size. 相似文献
184.
185.
Successful Transcatheter Embolization of Pseudoaneurysm Associated with Pancreatic Pseudocyst 总被引:1,自引:0,他引:1
Rikako Morita M.D. Nobuyoshi Muto M.D. Minoru Konagaya M.D. Tatsuya Honda M.D. Masayuki Miyazawa M.D. Satoshi Nakazawa M.D. Nobuhiro Kondo M.D. Norio Kimura M.D. Toshihiro Miura M.D. Shigeru Harasawa M.D. Takeshi Miwa M.D. Osamu Horie M.D. Yutaka Tanaka M.D. Makoto Ootaki M.D. 《The American journal of gastroenterology》1991,86(9):1264-1267
Hemorrhage into a pancreatic pseudocyst is a rare event, but is the most rapidly lethal complication of chronic pancreatitis. Visceral-vessel aneurysms are an unexpectedly common finding in arteriography of patients with chronic pancreatitis. This case report describes bleeding from an anterior superior pancreaticoduodenal artery aneurysm, caused by chronic pancreatitis. The aneurysm was successfully treated by embolization with a steel coil. 相似文献
186.
Masaru Nakagawa Syogo Kimura Keiji Fujimoto Hirokatsu Atumi Jyunko Imura Yoshihiro Chikazawa Hidetsugu Imamura Hiroshi Okuyama Hideki Yamaya Toshihiro Fukushima Atsushi Nakagawa Mitsuhiro Asaka Hitoshi Yokoyama 《Therapeutic apheresis and dialysis : official peer-reviewed journal of the International Society for Apheresis, the Japanese Society for Apheresis, the Japanese Society for Dialysis Therapy》2008,12(6):509-513
Plasmapheresis for the treatment of hypertriglyceridemia has previously been performed in patients with sudden onset severe hypertriglyceridemia and acute pancreatitis; however, only a few reports of this procedure have been published. We report here on a case showing severe hypertriglyceridemia during asparaginase (Asp) treatment for acute lymphocytic leukemia (ALL), and give an overview of a lipid‐lowering apheresis therapy. To prevent the complication of pancreatitis due to hypertriglyceridemia, we performed plasma exchange (PE) three times using fresh frozen plasma. PE remarkably reduced both serum triglyceride and total cholesterol levels from 5430 mg/dL to 403 mg/dL and from 623 mg/dL to 204 mg/dL, respectively. The causes of severe hyperlipidemia in this patient were considered to include: the Asp treatment for ALL, and a genetic background with a heterozygote of familial lipoprotein lipase (LPL) defect syndrome, because the patient's plasma LPL level after intravenous heparin injection was low at 137 ng/mL. Hence, PE using fresh frozen plasma may be useful not only to remove lipoproteins, but also to supply defective factors, such as LPL, in similar cases. 相似文献
187.
Atsushi Iwata Shin-ichiro Miura Satoshi Imaizumi Yoshihiro Kiya Hiroaki Nishikawa Bo Zhang Hideki Shimomura Koichiro Kumagai Kunihiro Matsuo Kazuyuki Shirai Keijiro Saku 《Circulation journal》2007,71(1):32-38
BACKGROUND: Many angiotensin II type 1 receptor blockers (ARBs) are available for clinical use, but because they do not all have the same effects, the present study investigated whether all benefits conferred by ARBs are class effects. METHODS AND RESULTS: Study 1 was a case-control study of patients with coronary artery disease, which showed that a non-depressor dose of valsartan significantly decreased the rate of target lesion revascularization at 6 months after stenting compared with the control group without ARB treatment. In Study 2, 44 patients with acute myocardial infarction who randomly received an initial lower dose of either valsartan or losartan after stenting were evaluated. The late loss and decrease in %diameter stenosis in the valsartan group were significantly lower than those in the losartan group as assessed by quantitative coronary angiography after 6 months. In addition, the valsartan group showed a significantly lower expression of intracellular adhesion molecule-1 and L-selectin. CONCLUSION: A non-depressor dose of ARB may have beneficial effects on coronary restenosis that are associated with the regulation of adhesion molecules, and these effects might not be a class effect of ARBs. 相似文献
188.
189.
Naoto Komada Minako Yamagata Kazutaka Komura Katsuhiro Hayashi Toshihiro Maruyama Hiroaki Kataoka Masashi Koono Hirohito Tsubouchi 《Journal of gastroenterology》1997,32(1):95-101
We report an autopsy case of hepatocellular carcinoma (HCC) with sarcomatous change arising in the context of primary biliary cirrhosis (PBC) in a 79-year-old man. Primary biliary cirrhosis was diagnosed (stage I according to Scheuer's classification) by findings on blood biochemical analysis, laparoscopy, and liver biopsy at age 69 years. Five years later, (at age 74 years), a mass lesion was detected in the S6 region of the liver by abdominal ultrasonography, and target biopsy revealed well differentiated HCC. Blood biochemistry, ultrasonography, and computed tomography findings showed that the PBC had progressed to stage IV (cirrhotic stage). Percutaneous ethanol injection therapy (PEIT) was administered to the HCC several times over a 5-year period; however, the patient died of liver failure in February, 1994 (at age 79 years). Viral markers for hepatitis B and C were negative during the course, and hepatitis C virus RNA was not detected by polymerase chain reaction. Autopsy findings showed liver cirrhosis and diffuse involvement of spindle-shaped sarcomatoid cells in the liver, particularly in the S6 region, associated with several nodules of trabecular HCC cells. A zone of transition between the sarcomatoid cells and the trabecular hepatocellular carcinoma cells was observed. The sarcomatoid cells were diffusely disseminated in the peritoneal cavity and had metastasized to multiple organs. Immunohistochemically, the cells were positive for fibrinogen, as were the coexisting trabecular hepatocellular carcinoma cells. The HCC had been treated several times with PEIT. Of interest, PEIT may be an important factor in this type of tumor progression. 相似文献
190.
PURPOSE: The gross appearance of colorectal carcinoma liver metastases reflects the biologic behavior of the tumor, yielding prognostic information. The aims of this retrospective study were to determine whether preoperative computed tomographic features of colorectal carcinoma liver metastases reflect the gross appearance of resected specimens and whether these computed tomographic hepatic features predict survival after hepatectomy. METHODS: Eighty-five patients underwent curative partial hepatectomy for colorectal carcinoma liver metastases. Preoperative computed tomographic features of the largest hepatic deposit were classified by the contour of advancing margin of the tumor into two types: lobular tumors with indentations with an acute angle and nonlobular tumors without such indentations. The correlation between computed tomographic features and 18 other clinicopathologic factors was examined. RESULTS: The overall five-year survival rate was 34.1 percent. Of 85 hepatic tumors examined, 49 were lobular and 36 were nonlobular. Computed tomographic features correlated significantly with gross appearance (P = 0.007). Univariate analysis revealed that computed tomographic features (P < 0.0001), gross appearance (P = 0.0063), size of the largest hepatic deposit (P = 0.0075), age (P = 0.0140), and satellite lesions (P = 0.0443) were significant prognosticators. The five-year survival rates in patients with lobular and nonlobular tumors were 10.4 and 66.1 percent, respectively. By multivariate analysis, computed tomographic features (P < 0.0001) and size of the largest hepatic deposit (P = 0.0419) were independently significant. CONCLUSIONS: Computed tomographic features of colorectal carcinoma liver metastases correlate with their gross appearance. The computed tomographic characterization of liver metastases is the most important independent prognostic factor in patients undergoing curative hepatectomy. 相似文献