全文获取类型
收费全文 | 476351篇 |
免费 | 20703篇 |
国内免费 | 845篇 |
专业分类
耳鼻咽喉 | 6757篇 |
儿科学 | 17085篇 |
妇产科学 | 15672篇 |
基础医学 | 68136篇 |
口腔科学 | 12869篇 |
临床医学 | 38194篇 |
内科学 | 87830篇 |
皮肤病学 | 10522篇 |
神经病学 | 31821篇 |
特种医学 | 21688篇 |
外国民族医学 | 139篇 |
外科学 | 73411篇 |
综合类 | 8769篇 |
现状与发展 | 1篇 |
一般理论 | 161篇 |
预防医学 | 35298篇 |
眼科学 | 10959篇 |
药学 | 33477篇 |
2篇 | |
中国医学 | 913篇 |
肿瘤学 | 24195篇 |
出版年
2018年 | 6966篇 |
2017年 | 6388篇 |
2016年 | 6113篇 |
2015年 | 8128篇 |
2014年 | 8618篇 |
2013年 | 10379篇 |
2012年 | 18387篇 |
2011年 | 13811篇 |
2010年 | 8131篇 |
2009年 | 9161篇 |
2008年 | 10485篇 |
2007年 | 12029篇 |
2006年 | 12131篇 |
2005年 | 19695篇 |
2004年 | 20834篇 |
2003年 | 16062篇 |
2002年 | 10953篇 |
2001年 | 17172篇 |
2000年 | 15140篇 |
1999年 | 16610篇 |
1998年 | 3492篇 |
1997年 | 3021篇 |
1996年 | 2948篇 |
1995年 | 2880篇 |
1992年 | 14453篇 |
1991年 | 14790篇 |
1990年 | 14807篇 |
1989年 | 14332篇 |
1988年 | 13108篇 |
1987年 | 12685篇 |
1986年 | 12135篇 |
1985年 | 11244篇 |
1984年 | 8019篇 |
1983年 | 6764篇 |
1982年 | 3377篇 |
1980年 | 2765篇 |
1979年 | 7923篇 |
1978年 | 5405篇 |
1977年 | 4384篇 |
1976年 | 3925篇 |
1975年 | 5132篇 |
1974年 | 6209篇 |
1973年 | 5921篇 |
1972年 | 5690篇 |
1971年 | 5509篇 |
1970年 | 5236篇 |
1969年 | 4903篇 |
1968年 | 4645篇 |
1967年 | 4412篇 |
1966年 | 4052篇 |
排序方式: 共有10000条查询结果,搜索用时 3 毫秒
981.
982.
Growth in Turkish children in Stockholm 总被引:1,自引:0,他引:1
S Mj?nes 《Annals of human biology》1987,14(4):337-347
Height, weight and body proportions were studied in 155 Turkish school children born in Sweden, living in a defined area in Stockholm. They were compared with Swedish children matched for sex, age and physical environment, and with a smaller number of Turkish children born in Turkey or in countries other than Turkey and Sweden. Parents' socio-economic levels were extremely low on a Swedish comparison. Growth was correlated to socio-economic background. The study was cross-sectional and longitudinal, combining growth data for key ages from health documents with contemporary data. Turkish schoolchildren under 10 years of age, born in Sweden, were significantly shorter than Swedish children, the difference beginning in the pre-school years. Turkish children born in Turkey were short on arrival in Sweden but soon caught up with the Turkish children born in Sweden. Genetic factors only could not explain the difference in height-for-age between Turkish children born in Sweden and Swedish children. With a longer period of stay in Sweden an increase in height-for-age would be expected. 相似文献
983.
984.
M P?iv?nsalo J Heikkil? K Huttunen 《R?ntgen-Bl?tter; Zeitschrift für R?ntgen-Technik und medizinisch-wissenschaftliche Photographie》1987,40(4):110-112
A change in transplant size, which can easily be measured by ultrasound, is one indicator of acute or chronic rejection. We report here on 49 areal measurements of transplant size from a coronal section and compare the results with isotopically measured areas. The areas measured in the isotope examinations correlated well with those measured sonographically (r = 0.82) in the case of the 33 transplants with a normal perfusion index but poorly (r = 0.45) in those with an abnormal perfusion index. The sonographically measured transplant area was about 85 cm2 in cases of acute rejection, 54 cm2 in cases of chronic rejection and 62 cm2 in cases with normal or slightly impaired transplant function (creatinine level below 200 mumol). Sonography is more suitable than isotope examination for monitoring transplant size in cases with poor perfusion. 相似文献
985.
Low molecular weight heparin plus dihydroergotamine for prophylaxis of postoperative deep vein thrombosis 总被引:2,自引:0,他引:2
A A Sasahara K Koppenhagen R H?ring D Welzel H Wolf 《The British journal of surgery》1986,73(9):697-700
In a prospective, double-blind investigation of the prophylaxis of deep vein thrombosis (DVT) in patients undergoing elective major abdominal surgery, 269 patients were randomized into two groups. One hundred and thirty-two patients received a fixed combination of heparin sodium 5000 units plus dihydroergotamine mesylate 0.5 mg (H/DHE) twice a day and 137 patients received a fixed combination of low molecular weight heparin 1500 units plus dihydroergotamine mesylate 0.5 mg (LMWH/DHE) once a day as well as one injection of placebo per day. Treatment was initiated 2 h pre-operatively in both groups and continued for 7-10 days. The frequency of DVT determined by the 125I-labelled fibrinogen uptake test and phlebography was 10.3 per cent in patients receiving H/DHE and 10.4 per cent in those receiving LMWH/DHE. DVT of the femoral vein was detected in four patients of the H/DHE group and in none of the LMWH/DHE group. Intra- and postoperative blood loss did not differ significantly between both groups. Also no difference in the development of wound haematoma and injection site haematoma was found. While intra-operative volume substitution was comparable in both groups, significantly more patients under H/DHE prophylaxis received volume substitution during the postoperative phase. These results show that once-daily prophylaxis with the combination of low molecular weight heparin and dihydroergotamine is equally as effective and as safe as the twice-daily regimen using a combination of unfractionated heparin and dihydroergotamine in patients undergoing elective, major abdominal surgery. The advantages of the once-daily regimen of LMWH/DHE include greater patient acceptance, less nursing time and greater cost effectiveness, provided the new combination can be sold at a cost which maintains this advantage. 相似文献
986.
Treatment of migraine with ergot alkaloids may produce systemic vasospasm in patients, especially as a result of automedication and overconsumption but also due to individual hypersensitivity. Peripheral vasoconstriction may lead to gangrene of the extremities, necessitating amputation. Various treatments have been tried against ischemic complications during ergotism with varied and unpredictable results. We report two recent cases of severe acute peripheral ischemia due to ergotamine abuse successfully treated with continuous systemic sodium nitroprusside infusion. The doses used during intraarterial injection are well below those known to be toxic. Consequently, the adverse effects of cyanide toxicity can be avoided. We think that intraarterial infusion of sodium nitroprusside, associated with forced diuresis and the administration of hydroxycobalamin, constitutes the treatment of choice of extreme peripheral ischemia of ergotism. 相似文献
987.
Effect of phosphorylation in vitro of human fibrinogen with protein kinase C on thrombin-induced gelation 总被引:1,自引:0,他引:1
Thrombin-induced gel formation of fibrinogen phosphorylated by protein kinase C yielded a transparent gel, whereas unphosphorylated fibrinogen yielded a coarse gel. The mass-length ratio was found to be one order of magnitude higher for the unphosphorylated than for the phosphorylated fibrinogen. Since the phosphorylated sites are located near the cross-linking sites in the A alpha-chain of fibrinogen, it is likely that the introduction of charged phosphate groups in this region prevent the lateral growth of the fibrin fibres. 相似文献
988.
989.
P G Bj?rnstad B K Semb 《Scandinavian journal of thoracic and cardiovascular surgery》1986,20(1):47-52
Cardiac function and changes following surgery was studied with computerized M-mode echocardiography in 12 patients with volume load of the left ventricle. Half of them had congenital lesions, the other half aortic regurgitation. Left ventricular (LV) shortening fraction and LV ejection time were significantly reduced postoperatively and came close to normal mean values. Also cardiac output and LV diameters normalized or at least started its normalization. The computerized values for rates of decrease and increase of left ventricular diameter were reduced postoperatively (p less than 0.01 and p less than 0.05 respectively) compared to elevated preoperative values. The study shows that relief of volume load on the left ventricle immediately leads to normalization of left ventricular function, especially if the myocardium was intact preoperatively. 相似文献
990.
T Okamura T Takeuchi O Nishii T Yaginuma T Kawana 《Nippon Sanka Fujinka Gakkai zasshi》1987,39(11):2059-2065
Ten puerperal women were put on a 1,200 kcal diet per day for 3 days followed by an ordinary 1,800 kcal diet per day for 3 days [Low-Caloric (LC) group]. Fifteen puerperal women were put on an ordinary 1,800 kcal diet per day for 6 days[Ordinary-Caloric (OC) group]. All of the women took breakfast at 7:30 am, blood was drawn at 9:30 am and then the breasts were milked for 2 minutes with an electric breast pump starting on the day of delivery (Day 0) and continuing to Day 5. Four women in the LC and OC groups underwent a thyrotropin-releasing hormone (TRH) stimulation test on Days 1 and 3. Serum prolactin (PRL) and TSH levels in the LC group tended to be much lower than those of the OC group during the test period. Serum PRL and TSH release response to TRH in the OC group were much higher than in the LC group on Days 1 and 3. No significant difference was noted between the OC and LC groups in serum estradiol (E2) and cortisol levels from Day 0 to Day 5. The milk volume in the LC group was significantly less than in the OC group on Day 1. Analysis of milk specimen components revealed little difference between the OC and LC groups. These results suggested that a low-caloric diet may suppress PRL, TSH and milk secretion and may not be useful for breast-feeding. 相似文献