全文获取类型
收费全文 | 4306008篇 |
免费 | 352777篇 |
国内免费 | 17551篇 |
专业分类
耳鼻咽喉 | 61108篇 |
儿科学 | 133306篇 |
妇产科学 | 111999篇 |
基础医学 | 657570篇 |
口腔科学 | 119285篇 |
临床医学 | 391367篇 |
内科学 | 778877篇 |
皮肤病学 | 103429篇 |
神经病学 | 367177篇 |
特种医学 | 171451篇 |
外国民族医学 | 927篇 |
外科学 | 654457篇 |
综合类 | 131772篇 |
现状与发展 | 30篇 |
一般理论 | 2580篇 |
预防医学 | 363993篇 |
眼科学 | 101285篇 |
药学 | 305195篇 |
48篇 | |
中国医学 | 13413篇 |
肿瘤学 | 207067篇 |
出版年
2021年 | 57379篇 |
2020年 | 36835篇 |
2019年 | 59587篇 |
2018年 | 74199篇 |
2017年 | 56927篇 |
2016年 | 63102篇 |
2015年 | 76952篇 |
2014年 | 112030篇 |
2013年 | 177178篇 |
2012年 | 119685篇 |
2011年 | 122840篇 |
2010年 | 124510篇 |
2009年 | 127329篇 |
2008年 | 109183篇 |
2007年 | 115491篇 |
2006年 | 124942篇 |
2005年 | 119823篇 |
2004年 | 120427篇 |
2003年 | 111009篇 |
2002年 | 101544篇 |
2001年 | 154744篇 |
2000年 | 150932篇 |
1999年 | 139931篇 |
1998年 | 71529篇 |
1997年 | 68012篇 |
1996年 | 65885篇 |
1995年 | 61734篇 |
1994年 | 55781篇 |
1993年 | 51735篇 |
1992年 | 103701篇 |
1991年 | 99059篇 |
1990年 | 94127篇 |
1989年 | 91763篇 |
1988年 | 85385篇 |
1987年 | 83857篇 |
1986年 | 79533篇 |
1985年 | 77950篇 |
1984年 | 65953篇 |
1983年 | 58862篇 |
1982年 | 48135篇 |
1981年 | 44883篇 |
1980年 | 42165篇 |
1979年 | 57830篇 |
1978年 | 47028篇 |
1977年 | 41589篇 |
1976年 | 38651篇 |
1975年 | 37844篇 |
1974年 | 42413篇 |
1973年 | 40546篇 |
1972年 | 38015篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
M B?ttner J Christoffel G Rimoldi W Wuttke 《Experimental and clinical endocrinology & diabetes》2006,114(2):82-90
The lack of estrogen during menopause is associated with various symptoms including osteoporosis, cardiovascular diseases, and menopausal symptoms. For many years, conventional hormone replacement therapy has been successfully used to treat these conditions. However, in light of recent studies that draw attention to potential hazards of conventional HRT, various attempts were undertaken to search for alternatives of classical HRT. Phytoestrogens are supposed to ameliorate various discomforts associated with menopause. Resveratrol (RES) is present in red wine, grapes and peanuts and has been implicated in cardioprotection and prevention of adverse side effects observed after regular HRT. As the pituitary-thyroid axis is a target of estrogen action, we first assessed the effects of E2 administration on thyroid hormone stimulating hormone releasing hormone (TRH)-induced thyroid stimulating hormone (TSH) secretion from pituitary cell cultures in vitro. Our data reveal that E2 treatment augments the TRH-induced TSH secretion. We furthermore designed a long-term study of three months to assess the effects of subcutaneous and oral administration of 17beta-estradiol (E2), as well as the actions of RES on the pituitary-thyroid axis in ovariectomized (OVX) female rats. Our results demonstrate that serum levels of 1.0 and 8.1 microM RES lead to a significant increase in total serum triiodthyronine (T3) levels. OVX induces TSHbeta mRNA in the adenohypohysis and E2 treatment attenuates this effect. Treatment of rats with subcutaneous implants of E2 does not affect the pituitary-thyroid axis, whereas orally applied E2 benzoate (E2B) increases plasma TSH and total thyroxine (T4) in OVX rats. In all animals, we could not detect changes in thyroid morphology as assessed by hematoxylin-eosin (HE) and Perjod-Acid Schiff's (PAS) staining. 相似文献
992.
S Chinn S H Downs J M Anto M W Gerbase B Leynaert R de Marco C Janson D Jarvis N Künzli J Sunyer C Svanes E Zemp U Ackermann-Liebrich P Burney 《The European respiratory journal》2006,28(4):763-771
The incidence of asthma has been reported to be associated with obesity. An alternative analysis, of net change in prevalence, does not require exclusion of those with asthma at baseline. Follow-up data were obtained from 9,552 participants in the European Community Respiratory Health Survey and the Swiss cohort Study on Air Pollution and Lung Disease in Adults. Incidence of asthma was analysed by proportional hazards regression, and net changes in symptoms and asthma status by generalised estimating equations, by obesity group. Incidence and net change in ever having had asthma were greater in females than in males, and in participants who remained obese compared with those who were never obese (hazard ratio 2.00, 95% confidence interval 1.25-3.20; excess net change 2.8%, 0.4-5.3% per 10 yrs). The effect of being obese on net change in diagnosed asthma was greater in females than in males, but for net change in wheeze without a cold it was greater in males. The present results are consistent with asthma being more frequently diagnosed in females, especially obese females. These findings may help to explain the reports of a stronger association between asthma and obesity in females than in males. 相似文献
993.
Abstract – The aim of this study was to investigate mechano-sensory responses of injured and uninjured incisor teeth. Twenty-five children who had experienced dental trauma, together with age- and gender-matched controls, were studied prospectively. Touch thresholds of incisor teeth from both groups were determined using calibrated sets of von Frey hairs (force range 0.5–10.0 g in 0.5 g increments) using a forced choice staircase method. Forces were applied perpendicular to the buccal enamel surfaces along the midline, 2 mm from the incisal edge. Touch threshold was defined as the lowest force detected in three out of the five occasions. Following statistical analysis, P < 0.05 was considered significant. At initial examination, the touch threshold values of 25 traumatised teeth were significantly greater than the untraumatised controls ( P < 0.001), and these values approached those of the control teeth over 3–12 months ( P > 0.05). Dental trauma was associated with increased touch thresholds in permanent incisor teeth, with recovery toward healthy control values usually occurring between 3–12 months. 相似文献
994.
995.
996.
997.
本文报告了暗纹节菱孢[Arthinium phaeospemum(Corda)Ellis]所致皮肤真菌病的组织病理学及超微结构观察。HE、PAS、镀银染色(Szatri)法及铅铀染色,对皮损的组织病理改变,进行了光镜及透射电镜观察。光镜下发现暗纹节菱孢引起真皮及皮下脂肪组织广泛性病理浸润,由多种细胞构成的肉芽肿,尤其对皮肤附属器严重破坏。在病理浸润中可见球形、卵圆形、菱形及晶体形,玫瑰红色、棕色及褐色孢子。透射电镜下见真皮成纤维细胞胞浆内吞噬多数界线清楚的圆形小体,空泡内也有相同的小体,胞浆空泡甚多,胞核完整。同时见到破坏的溶酶体。病理浸润内形态各异的孢子及不同颜色,是孢子生长的不同阶段。 相似文献
998.
Esophageal foreign body causing direct aortic injury. 总被引:4,自引:0,他引:4
Foreign bodies in the esophagus are uncommon causes of esophageal perforation. Many nonperforating cases are successfully managed by flexible gastroscopy. However, complicated foreign bodies such as those that result in esophageal perforation and vascular injury are best managed surgically. Gastroscopy remains the primary method of diagnosis. A case of a 59-year-old woman who developed retrosternal and intrascapular pain, odynophagia and hematemesis after eating fish is reported. Flexible gastroscopy showed arterial bleeding from the midthoracic esophagus. Computed tomography scan localized a 3 cm fish bone perforating the esophagus with surrounding hematoma. An aortogram did not reveal an actively bleeding aortoesophageal fistula. The fish bone was surgically removed and the patient recovered with no postoperative complications. This case illustrates the importance of early consideration for surgical intervention when confronted with a brisk arterial bleed from the esophagus with suggestive history of foreign body ingestion. 相似文献
999.
This review discusses treatment options for men with premature ejaculation (PE), a common sexual dysfunction characterized
by short ejaculatory latency, decreased sexual satisfaction, and distress. For a number of reasons, including embarrassment
and the belief that PE is a normal part of aging, that it has no effective treatment, or that it will resolve itself, few
men with PE seek treatment. Although several treatment options exist (eg, behavioral, cognitive, and sex therapy methods;
desensitizing drugs; off-label use of antidepressants, phosphodiesterase type 5 inhibitors, or à-blockers), the majority of
men with PE are not satisfied with their results. New pharmacologic drugs develped specifically for the treatment of PE are
undergoing evaluation in clinical trials. For example, recent clinical research studies have revealed on-demand administration
of one such drug, dapoxetine, which achieved significant improvements in ejaculatory latency, control over ejaculation, and
satisfaction with sexual intercourse. In addition, partners of men who received dapoxetine likewise reported improved satisfaction
with sexual intercourse. Future studies may reveal that integration of pharmacologic drugs with psychologic and/or behavioral
therapy techniques may be the optimal approach to the management of PE. PE is a treatable condition, and new drugs in development
may provide benefits over those available. 相似文献
1000.
目的研究腹内压升高对大鼠中心静脉压和门静脉压的影响。方法将20只成年雄性SD大鼠分别通过颈静脉插管、穿刺门静脉主干法来测定中心静脉压和门静脉压,运用氮气气腹法制作大鼠腹内高压动物模型。建立气腹后分别在0、5、10、15、20、25、30、35、40、45mmHg压力值下测得中心静脉压和门静脉压。结果中心静脉压和腹内压之间的直线回归方程为Y=2.824+0.045X,相关系数r=0.984(P〈0.01);门静脉压和腹内压之间的直线回归方程为Y=8.887+0.939X,相关系数r=0.998(P〈0.01)。结论腹内压与中心静脉压和门静脉压有很好的相关性,可以根据腹内压监测中心静脉压和门静脉压的变化。 相似文献