全文获取类型
收费全文 | 36427篇 |
免费 | 1637篇 |
国内免费 | 298篇 |
专业分类
耳鼻咽喉 | 266篇 |
儿科学 | 671篇 |
妇产科学 | 419篇 |
基础医学 | 4843篇 |
口腔科学 | 1005篇 |
临床医学 | 2135篇 |
内科学 | 9069篇 |
皮肤病学 | 859篇 |
神经病学 | 2459篇 |
特种医学 | 1265篇 |
外科学 | 6496篇 |
综合类 | 146篇 |
一般理论 | 1篇 |
预防医学 | 1007篇 |
眼科学 | 634篇 |
药学 | 2145篇 |
中国医学 | 124篇 |
肿瘤学 | 4818篇 |
出版年
2024年 | 25篇 |
2023年 | 203篇 |
2022年 | 539篇 |
2021年 | 886篇 |
2020年 | 452篇 |
2019年 | 652篇 |
2018年 | 851篇 |
2017年 | 658篇 |
2016年 | 776篇 |
2015年 | 808篇 |
2014年 | 1085篇 |
2013年 | 1384篇 |
2012年 | 2250篇 |
2011年 | 2638篇 |
2010年 | 1487篇 |
2009年 | 1220篇 |
2008年 | 2248篇 |
2007年 | 2480篇 |
2006年 | 2319篇 |
2005年 | 2497篇 |
2004年 | 2407篇 |
2003年 | 2406篇 |
2002年 | 2420篇 |
2001年 | 391篇 |
2000年 | 323篇 |
1999年 | 444篇 |
1998年 | 581篇 |
1997年 | 455篇 |
1996年 | 438篇 |
1995年 | 372篇 |
1994年 | 325篇 |
1993年 | 300篇 |
1992年 | 224篇 |
1991年 | 204篇 |
1990年 | 190篇 |
1989年 | 176篇 |
1988年 | 160篇 |
1987年 | 116篇 |
1986年 | 102篇 |
1985年 | 99篇 |
1984年 | 111篇 |
1983年 | 89篇 |
1982年 | 73篇 |
1981年 | 87篇 |
1980年 | 82篇 |
1979年 | 59篇 |
1978年 | 43篇 |
1977年 | 32篇 |
1976年 | 25篇 |
1975年 | 25篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
51.
Takashi Murakami Hitoshi Horigome Kiyoji Tanaka Yoshio Nakata Yasutomi Katayama Akira Matsui 《Blood coagulation & fibrinolysis》2007,18(5):389-394
Obesity is a risk factor for cardiovascular disease and thromboembolic events. We investigated the effects of weight reduction by a 12-week calorie-restricted diet with or without aerobic exercise (diet group and diet plus exercise group) on leptin and anticoagulation proteins levels. Forty-two obese nondiabetic individuals were evaluated for blood levels of leptin, protein C activity, free protein S antigen and for body fat area calculated on computerized tomography before and after intervention. Before intervention, serum levels of leptin and free protein S antigen correlated positively with several adiposity-related parameters. After the program, body weight and fat area were significantly decreased in both groups. Body mass index and leptin levels decreased in both groups, with a larger change in the diet plus exercise group than in the diet group. Although protein C activity levels did not change in both groups, free protein S antigen levels decreased significantly in the diet plus exercise group. In conclusion, the 12-week programs had significant effects on the initial weight reduction and body fat mass, decreasing lepin levels in obese nondiabetic individuals. To clarify whether aerobic exercise has additional or direct effects on the anticoagulation system, a study in a large number of individuals is needed. 相似文献
52.
Pharmacologic preconditioning effects: Prostaglandin E1 induces heat-shock proteins immediately after ischemia/reperfusion of the mouse liver 总被引:1,自引:0,他引:1
Ken-ichi Matsuo M.D. Shinji Togo M.D. Ph.D. Hitoshi Sekido M.D. Ph.D. Tomoyuki Morita M.D. Ph.D. Masako Kamiyama Ph.D. Daisuke Morioka M.D. Ph.D. Toru Kubota M.D. Ph.D. Yasuhiko Miura M.D. Ph.D. Kuniya Tanaka M.D. Ph.D. Takashi Ishikawa M.D. Ph.D. Yasushi Ichikawa M.D. Ph.D. Itaru Endo M.D. Ph.D. Hitoshi Goto M.D. Ph.D. Hiroyuki Nitanda M.D. Ph.D. Yasushi Okazaki M.D. Ph.D. Yoshihide Hayashizaki M.D. Ph.D. Hiroshi Shimada M.D. Ph.D. 《Journal of gastrointestinal surgery》2005,9(6):758-768
Prostaglandin E1 (PGE1) has several potential therapeutic effects, including cytoprotection, vasodilation, and inhibition of platelet aggregation. This study investigates the protective action of PGE1 against hepatic ischemia/reperfusion injury in vivo using a complementary DNA microarray. PGE1 or saline was continuously administered intravenously to mice in which the left lobe of the liver was made ischemic for 30 minutes and then reperfused. Livers were harvested 0, 10, and 30 minutes postreperfusion. Messenger RNA was extracted, and the samples were labeled with two different fluorescent dyes and hybridized to the RIKEN set of 18,816 full-length enriched mouse complementary DNA microarrays. Serum alanine aminotransferase and aspartate aminotransferase levels at 180 minutes postreperfusion were significantly lower in the PGE1-treated group than in the saline-treated group. The cDNA microarray analysis revealed that the genes encoding heat-shock protein (HSP) 70, glucose-regulated protein 78, HSP86, and glutathione S-transferase were upregulated at the end of the ischemic period (0 minutes postreperfusion) in the PGE1 group. Our results suggested that PGE1 induces HSPs immediately after ischemia reperfusion. HSPs might therefore play an important role in the protective effects of PGE1 against ischemia/reperfusion injury of the liver. 相似文献
53.
Takashi Yamauchi Takafumi Masai Koji Takeda Satoshi Kainuma Yoshiki Sawa Kazuo Abe 《Annals of thoracic and cardiovascular surgery》2007,13(6):410-412
We report a rare case of constrictive pericarditis that stimulated a large mediastinal tumor obstructing the right ventricular inflow tract. A 58-year-old woman was referred to our hospital because of a recent increase of dyspnea and facial edema. Computed tomography revealed severely thickened calcification, including a low-density area, presenting as a mediastinal tumor, compressing the right ventricular inflow tract. A complete resection was performed, and her symptoms dramatically improved. Idiopathic constrictive pericarditis was diagnosed pathologically. 相似文献
54.
Osamu Mori Minoru Miyasato Tadashi Karashima Takashi Hashimoto 《The Journal of dermatology》1998,25(8):497-502
Previous studies using primary monolayer cultures of epithelial cells from the involved epidermis of patients with mammary and extramammary Paget's disease investigated whether Paget cells proliferate as other malignant cells do. Although epithelial monolayers from the involved skin were maintained for approximately 45 days, no permanent cell lines were established. The proportion of carcinoembryonic antigen (CEA)-positive cells did not increase in the long-term cultures. Herein, we report studies of whether there is a real reduction of Paget cell numbers or if this is merely a decrease in the expression of CEA by the cells. Furthermore, we investigated whether Paget cells survive longer when cultured free from any potential inhibitory keratinocytes or other epidermal cells. Skin samples were obtained from one patient with mammary Paget's disease and three with extramammary Paget's disease; epidermal cells were cultured in vitro. An enrichment of Paget cells was carried out from the cultured epidermal cells by combining an anti-epithelial membrane antigen monoclonal antibody, binding to immunobeads, and density gradient centrifugation in Nycodenz. The separated cells were re-cultured in Keratinocyte-SFM serum-free media. The proportion of CEA-positive cells did not increase in the cultures, and the purified cells did not show any increase in survival times compared to the non-purified cultured cells. These results suggest that the decrease of CEA-positive cells noted during culture results from a decline in expression of CEA in the Paget cells. Paget cells in the involved epidermis do not proliferate significantly and thus differ from many other malignant cells. 相似文献
55.
Primary leiomyosarcoma of the thyroid gland 总被引:1,自引:0,他引:1
Osamu Ozaki Kiminori Sugino Takashi Mimura Kunihiko Ito Seiichi Tamai Yasuhiro Hosoda 《Surgery today》1997,27(2):177-180
Primary leiomyosarcoma of the thyroid gland is extremely rare, and to the best of our knowledge only five well-documented
cases have been reported in the world literature. We herein report a 58-year-old female patient with primary leiomyosarcoma
of the thyroid who was successfully treated by total thyroidectomy with a modified neck dissection. Immunohistochemically,
the tumor cells showed positive reactivity to α-smooth muscle actin and vimentin. Radical surgery was thus considered to be
essential in the treatment of this rare but rather aggressive malignancy. 相似文献
56.
We determined the serum levels of the creatine kinase B subunit (CK-B) by an enzyme immunoassay method in patients with renal cell carcinoma (RCC) and benign renal diseases. Eighteen of 76 patients with RCC (24%) had elevated serum CK-B levels. The positive rates were 29% in stage I, 13% in stage II, 15% in stage III, and 27% in stage IV. In all 9 patients whose serum CK-B levels were serially measured and had been elevated before operation, the CK-B levels were reduced to the normal range after nephrectomy. These findings indicate that serum CK-B is a useful biomarker for monitoring the clinical course for a limited number of RCC patients, but is not a marker for diagnosis and staging. Concentrations of CK-B in RCC tissues were significantly lower than those of normal kidney. A high rate of cell turnover in tumor tissues might entail the higher level of serum CK-B in patients with RCC. 相似文献
57.
Takashi Oono Yutaka Fujiwara Toshiko Yoshioka Jir Arata 《The Journal of dermatology》1997,24(10):626-629
We investigated prolidase activity in samples derived from wound fluid as well as blister fluid. Prolidase activity was elevated in fluid samples collected from wounds over the levels in sera collected from patients with chronic wounds (P<0.05). Prolidase activity was also present in samples taken from blister diseases. However, prolidase activity in blister fluid was not higher than that in sera collected from patients with blister diseases. Our results indicate that prolidase may play a role in wound healing. 相似文献
58.
Gen Matsuo Yasuo Matsumura Kiyoshi Tadano Takashi Hashimoto Shiro Morimoto 《Clinical and experimental pharmacology & physiology》1997,24(7):487-491
1. The effects of sarafotoxin S6c (S6c), a selective endothelin ETB receptor agonist, on renal haemodynamics and urine formation were examined in anaesthetized dogs. 2. Intrarenal arterial infusion of S6c at a rate of 1 or 5 ng/kg per min produced a transient increase in renal blood flow (RBF), with no change in systemic blood pressure and heart rate; RBF then decreased gradually to below the basal value. There were significant and dose-dependent increases in urine flow and free water clearance and decreases in urine osmolality during S6c infusion, whereas urinary excretion of sodium and glomerular filtration rate (GFR) remained unchanged. Simultaneously, S6c administration elicited a marked increase in urinary excretion of nitric oxide (NO) metabolites, N02? and N03? (UNO*V). 3. In dogs simultaneously administered S6c (5 ng/kg per min) and iVG-nitro-L-arginine (NOARG; 40 (jig/kg per min), a NO synthase inhibitor, the renal vasodilator effect of S6c was abolished and marked reductions in RBF and GFR were observed. The S6c-induced diuretic action was not affected by NOARG. In the presence of NOARG, there was a small amount of UNOxV at the basal level and the administration of S6c did not increase UNOxV. 4. These results suggest that an intrarenal arterial infusion of S6c enhances the production of NO in the kidney and that this enhancement contributes to the peptide-induced renal vasodilation. In contrast, it is unlikely that S6c-induced water diuresis is related to NO production stimulated by this peptide. 相似文献
59.
Gen Kawa Shigenari Kawakita Takashi Ohara Tadashi Matsuda 《International journal of urology》1997,4(3):327-328
A 2-year-old boy presented with an accessory scrotum associated with penoscrotal transposition and a perineal lipoma. He also had a retrocerebellar arachnoid cyst. The accessory scrotum was resected with concurrent scrotoplasty. The retrocerebellar arachnoid cyst was seen on a subsequent brain computed tomography scan and was left untreated because there was no evidence that the volume was increasing. 相似文献
60.
Kazunori Ikebe Kentaro Morii Jumpei Kashiwagi Takashi Nokubi Ronald L Ettinger 《Oral surgery, oral medicine, oral pathology, oral radiology, and endodontics》2005,99(6):704-710
OBJECTIVE: The purpose of this study was to determine the association of dry mouth with oral symptoms and function, such as denture instability, discomfort, soreness in denture-bearing tissue, and dissatisfaction with chewing, tasting, or speaking in removable denture wearers. STUDY DESIGN: The subjects were 493 removable denture wearers with a mean age of 67.3 years. Perception of oral dryness was measured by a questionnaire. A multiple logistic regression analysis was used to determine the effect of the dry mouth on oral symptoms and function after controlling for age and gender. RESULTS: Oral dryness during eating was related to dissatisfaction with chewing (odds ratio, 10.5; P < .001) and speaking (odds ratio, 3.5; P < .05) and overall dissatisfaction (odds ratio, 6.3; P < .01) in complete denture wearers. Feeling of dry mouth was likely to be associated with soreness in denture-bearing tissues in both complete and removable partial denture wearers. CONCLUSIONS: There was a significant association of the perception of dry mouth among a group of denture wearers with oral symptoms and function. 相似文献