全文获取类型
收费全文 | 4779篇 |
免费 | 265篇 |
国内免费 | 40篇 |
专业分类
耳鼻咽喉 | 25篇 |
儿科学 | 69篇 |
妇产科学 | 58篇 |
基础医学 | 582篇 |
口腔科学 | 124篇 |
临床医学 | 322篇 |
内科学 | 1063篇 |
皮肤病学 | 223篇 |
神经病学 | 343篇 |
特种医学 | 171篇 |
外科学 | 749篇 |
综合类 | 16篇 |
预防医学 | 162篇 |
眼科学 | 58篇 |
药学 | 539篇 |
中国医学 | 4篇 |
肿瘤学 | 576篇 |
出版年
2023年 | 21篇 |
2022年 | 45篇 |
2021年 | 70篇 |
2020年 | 32篇 |
2019年 | 43篇 |
2018年 | 79篇 |
2017年 | 68篇 |
2016年 | 82篇 |
2015年 | 69篇 |
2014年 | 83篇 |
2013年 | 89篇 |
2012年 | 161篇 |
2011年 | 183篇 |
2010年 | 125篇 |
2009年 | 102篇 |
2008年 | 178篇 |
2007年 | 200篇 |
2006年 | 197篇 |
2005年 | 219篇 |
2004年 | 187篇 |
2003年 | 227篇 |
2002年 | 216篇 |
2001年 | 209篇 |
2000年 | 229篇 |
1999年 | 215篇 |
1998年 | 81篇 |
1997年 | 49篇 |
1996年 | 59篇 |
1995年 | 54篇 |
1994年 | 48篇 |
1993年 | 42篇 |
1992年 | 146篇 |
1991年 | 146篇 |
1990年 | 110篇 |
1989年 | 145篇 |
1988年 | 109篇 |
1987年 | 114篇 |
1986年 | 86篇 |
1985年 | 84篇 |
1984年 | 59篇 |
1983年 | 45篇 |
1982年 | 31篇 |
1979年 | 47篇 |
1978年 | 28篇 |
1977年 | 20篇 |
1974年 | 25篇 |
1970年 | 19篇 |
1969年 | 21篇 |
1968年 | 19篇 |
1966年 | 20篇 |
排序方式: 共有5084条查询结果,搜索用时 46 毫秒
91.
Significance of platelet-derived microparticles and activated platelets in diabetic nephropathy 总被引:21,自引:0,他引:21
Omoto S Nomura S Shouzu A Hayakawa T Shimizu H Miyake Y Yonemoto T Nishikawa M Fukuhara S Inada M 《Nephron》1999,81(3):271-277
We measured levels of platelet-derived microparticles (PMP), which have coagulative activity and are produced by platelet activation or physical stimulation, and CD62P/CD63-positive platelets in patients with diabetes mellitus to determine their clinical significance and effects on complications of diabetes including diabetic nephropathy. We also compared these levels before and after administration of the antiplatelet drug cilostazol. Plasma PMP and CD62P/CD63-positive platelet levels were significantly higher in patients with diabetes mellitus than normal controls. CD62P-positive platelet levels were significantly higher in patients with nephropathy than in patients without complications. After administration of cilostazol, PMP and CD62P/CD63-positive platelet levels were significantly decreased. The increases in platelet activity and its related procoagulant activity appear to account in part for the hypercoagulability observed in diabetes mellitus. Our findings suggest that activated platelets might play a role in the development of diabetic nephropathy. Furthermore, antiplatelet therapy with cilostazol for diabetic patients may be useful as antithrombin therapy including antiplatelet therapy, since it suppresses the production of intrinsic coagulants produced by platelet activation. 相似文献
92.
Effects of hemodialysis membrane on serum lipid profile of maintenance hemodialysis patients 总被引:5,自引:0,他引:5
Atherosclerosis and lipid abnormalities are still insuperable complications for maintenance hemodialysis patients. We observed the serum lipid profile of 27 maintenance hemodialysis patients (M : F; 20 : 7, age; 54.9 +/- 6.2 y. o., hemodialysis duration; 10.8 +/- 4.9 years, body weight; 53.6 +/- 4.4 kg) using a low flux cellulose membrane, cellulose (1.5 m2), a vitamin-E-modified dialysis membrane, CL-15E (CL- 15E 1.5 m2, Terumo), and polysulfon, PS (PS-1.3UW 1.3 m2, Fresenius) dialysers. Each membrane dialyzer was used for 3 months. The blood flow rate was 200 ml/min, and hemodialysis time, 4 hours. When the dialyzers were replaced, fasting blood was collected at the beginning of hemodialysis and serum lipid parameters were measured. Seven additional maintenance hemodialysis patients were selected and TC, TG, HDL-C were measured as controls, because their dialyzers (low flux cellulose 1.5 m2) and hemodialysis conditions were not changed during the study. TC was decreased by PS and there were significant differences between cellulose and PS, and between CL-15E and PS. However, these changes were conducted within the normal range of TC. TG was not significantly changed during the study. HDL-C was decreased by CL-15E and PS as well as TC. There were significant differences in HDL-C between cellulose and CL-15E, and between cellulose and PS. Apo B, Apo B/A-I were decreased by PS and there were significant differences between cellulose and PS, respectively, LP(a) was not changed during the study. RLP-C (Cellulose vs. PS, CL-15E vs. PS), VLDL-C (Cellulose vs PS), and LDL-C (cellulose vs. PS, CL-15E vs. PS) were significantly decreased between membranes, respectively. Although the precise mechanism is yet unknown, the uptake of LDL and remnant into receptors of the liver might be improved by PS hemodialysis. In conclusion, these data suggest that PS decreased the serum levels of the lipid profile in maintenance hemodialysis patients and may be effective in improving their lipid abnormality. 相似文献
93.
Impaired glucose tolerance, diabetes mellitus, and gallstone disease: An extended study of male self-defense officials in Japan 总被引:2,自引:0,他引:2
Shizuka Sasazuki Suminori Kono Isao Todoroki Satoshi Honjo Yutaka Sakurai Kazuo Wakabayashi Masato Nishiwaki Hiroaki Hamada Hiroshi Nishikawa Hiroko Koga Shinsaku Ogawa Katsuya Nakagawa 《European journal of epidemiology》1999,15(3):245-251
Few studies have investigated the relation between glucose tolerance status and ultrasonographically determined gallstone disease. Using a 75-g oral glucose tolerance test, we examined the association of impaired glucose tolerance (IGT) and non-insulin-dependent diabetes mellitus (NIDDM) with gallstone disease in Japanese men. Subjects were men aged 48 to 59 of the Japan Self-Defense Forces who received a preretirement health examination between October 1986 to December 1994. After exclusion of 12 men under insulin treatment in the consecutive series of 7637 men, 174 were found to have gallstones; 103 were at the state of postcholecystectomy, and 6899 had normal gallbladder. IGT and NIDDM were associated with a modestly increased risk of gallstone disease; adjusted odds ratios were 1.3 (95% confidence interval [CI]: 0.9–1.8) for IGT and 1.3 (95% CI: 0.8–2.0) for NIDDM after adjustment for hospital, rank, smoking, alcohol use, and body mass index. Adjusted odds ratio for IGT and NIDDM combined was 1.3 (95% CI: 1.0–1.7, p=0.08). When prevalent gallstones and postcholecystectomy were considered separately, NIDDM showed a significant, positive association with postcholecystectomy, but not with prevalent gallstones. The findings add to evidence that glucose intolerance is associated with a modest increase in the risk of gallstone disease. 相似文献
94.
Haemodynamic alterations elicited by iced injectate during thermodilution cardiac output measurements were evaluated in the presence of metabolic acidosis or hypoxic hypoxia in 14 instrumented anaesthetized dogs. The alterations in some haemodynamic variables during slowing of the heart rate following injection of 3 ml iced injectate were slightly greater in metabolic acidosis and hypoxic hypoxia as compared to animals without metabolic acidosis or hypoxic hypoxia (P < 0.05), but the changes were clinically insignificant. No serious haemodynamic changes were found during any cardiac output measurement by thermodilution in the presence of metabolic acidosis or hypoxic hypoxia. The values of cardiac output measured by thermodilution correlated closely with those of pulmonary blood flow measured by an electromagnetic flowmeter in the metabolic acidosis and hypoxic hypoxia groups (r > 0.9). It is concluded that thermodilution using iced injectate will estimate right ventricular output accurately in conditions of metabolic acidosis and hypoxic hypoxia. 相似文献
95.
Chronological changes in nonhaemorrhagic brain Infarcts with short T1 in the cerebellum and basal ganglia 总被引:2,自引:0,他引:2
Our purpose was to investigate nonhaemorrhagic infarcts with a short T1 in the cerebellum and basal ganglia. We carried out
repeat MRI on 12 patients with infarcts in the cerebellum or basal ganglia with a short T1. Cerebellar cortical lesions showed
high signal on T1-weighted spin-echo images beginning at 2 weeks, which became prominent from 3 weeks to 2 months, and persisted
for as long as 14 months after the ictus. The basal ganglia lesions demonstrated slightly high signal from a week after the
ictus, which became more intense thereafter. Signal intensity began to fade gradually after 2 months. High signal could be
seen at the periphery until 5 months, and then disappeared, while low or isointense signal, seen in the central portion from
day 20, persisted thereafter.
Received: 1 February 1999 Accepted: 13 September 1999 相似文献
96.
97.
Wen Qing Yang Xueqing Lun Cheryl Ann Palmer M Elizabeth Wilcox Huong Muzik Zhong Qiao Shi Richard Dyck Matt Coffey Brad Thompson Mark Hamilton Sandra G Nishikawa Penny M A Brasher Kevin Fonseca David George N Berry Rewcastle Randal N Johnston Doug Stewart Patrick W K Lee Donna L Senger Peter A Forsyth 《Clinical cancer research》2004,10(24):8561-8576
PURPOSE: Human reovirus type 3 has been proposed to kill cancer cells with an activated Ras signaling pathway. The purpose of this study was to investigate the efficacy of reovirus in immunocompetent glioma animal models and safety/toxicity in immunocompetent animals, including nonhuman primates. EXPERIMENTAL DESIGN: Racine glioma cells 9L and RG2 were implanted s.c. or intracranially in Fisher 344 rats with or without reovirus antibodies, followed by treatment of reovirus. To study whether reovirus kills contralateral tumors in the brain and to determine viral distribution, we established an in situ dual tumor model followed by reovirus intratumoral inoculation only into the ipsilateral tumor. To evaluate neurotoxicity/safety of reovirus, Cynomolgus monkeys and immunocompetent rats were given intracranially with reovirus, and pathological examination and/or behavioral studies were done. Viral shedding and clinical biochemistry were systematically studied in monkeys. RESULTS: Intratumorally given reovirus significantly suppressed the growth of both s.c. and intracranially tumors and significantly prolonged survival. The presence of reovirus-neutralizing antibodies did not abort the reovirus' antitumor effect. Reovirus inhibited glioma growth intracranially in the ipsilateral but not the contralateral tumors; viral load in ipsilateral tumors was 15 to 330-fold higher than the contralateral tumors. No encephalitis or behavioral abnormalities were found in monkeys and rats given reovirus intracranially. No treatment-related clinical biochemistry changes or diffuse histopathological abnormality were found in monkeys inoculated intracranially with Good Manufacturing Practice prepared reovirus. Microscopic changes were confined to the region of viral inoculation and were dose related, suggesting reovirus intracranially was well tolerated in nonhuman primates. CONCLUSIONS: These data show the efficacy and safety of reovirus when it is used in the treatment of gliomas in immunocompetent hosts. Inoculation of reovirus into the brain of nonhuman primates did not produce significant toxicities. 相似文献
98.
Nishikawa T Iguchi T Honda H Harada T Kurosaka M Mizuno K 《Journal of spinal disorders》2000,13(4):360-364
Two case reports of femoral bone lesions simulating lumbar spinal disease are presented. Physical examination and case history were strongly suggestive of lumbar spinal pathology. In case 1, surgical resection of a venous hemangioma in the lumbar epidural space was performed but did not relieve pain. In case 2, conservative treatments for a protruded disk were performed for 3 months before an accurate diagnosis was made. After correct diagnoses were made, excision of the femoral tumors brought rapid relief of all abnormal findings in both cases. Compared with other causes of sciatica, femoral bone tumors are rare. However, careful attention should be paid to rule out these lesions if the diagnosis of a lumbar spinal disease is uncertain. Bone scintigraphy seems to be a sensitive diagnostic method to detect extraspinal osseous lesions. 相似文献
99.
H. Yamamoto K. Yamazaki S. Nishikawa T. Hayashi O. Hayakawa R. Kudo 《Archives of gynecology and obstetrics》1997,259(2):105-107
Case: We present a case of HELLP syndrome occuring in a patient who at the age of 8 years had undergone a splenectomy for
idiopathic thrombocytopenic purpura. She was diagnosed as having HELLP syndrome 37 weeks of gestation and had a cesarean section.
Received: 4 June 1996 / Accepted: 7 October 1996 相似文献
100.
Fumio Furukawa Akiyoshi Nishikawa Takayoshi Imazawa Ken-ichiro Kasahara Michihito Takahashi 《Cancer science》1998,89(2):131-136
The modifying effects of quinacrine administration during the post-initiation phase of carcinogenesis were investigated in hamsters treated with N -nitrosobis(2-oxopropyl)amine (BOP). Female Syrian hamsters were given three weekly s.c. injections of BOP at a dose of 10 mg/kg and then 300 or 100 ppm quinacrine in their diet for 37 weeks. Additional groups of animals received the BOP injection alone, or only the 300 ppm quinacrine treatment as BOP-negative controls. At week 40 of the experiment, all surviving animals were killed and development of proliferative lesions was assessed histopathologically. The multiplicity of pancreatic adenocarcinomas and dysplastic lesions per hamster was significantly higher ( P <0.01 and P <0.05) in the BOP/Q100 group (1.92 and 1.78) than in the BOP-alone group (1.07 and 0.79). The incidence of hepatocellular adenomas plus carcinomas was also significantly elevated ( P <0.05) in the BOP/Q300 and BOP/Q100 groups. In contrast, the multiplicity of lung adenomas plus adenocarcinomas was significantly decreased ( P <0.05) by the Q300 treatment. Neither the incidence nor the multiplicity of renal cell tumors (adenomas and carcinomas) or nephroblastomas significantly differed between the BOP-treated groups. Electron microscopic examination revealed an abundance of myeloid lamellar bodies filling the cytoplasm of hepatocytes and pancreatic ductular and acinar cells, and epithelial cells of the gallbladder in the quinacrine-treated animals, the degree being dose-dependent. Our results indicate that quinacrine enhances pancreatic and hepatic carcinogenesis in hamsters induced by BOP. 相似文献