全文获取类型
收费全文 | 2074389篇 |
免费 | 151899篇 |
国内免费 | 4261篇 |
专业分类
耳鼻咽喉 | 28918篇 |
儿科学 | 70120篇 |
妇产科学 | 59798篇 |
基础医学 | 301913篇 |
口腔科学 | 58531篇 |
临床医学 | 182471篇 |
内科学 | 402405篇 |
皮肤病学 | 45360篇 |
神经病学 | 162886篇 |
特种医学 | 80743篇 |
外国民族医学 | 653篇 |
外科学 | 315515篇 |
综合类 | 46548篇 |
现状与发展 | 1篇 |
一般理论 | 655篇 |
预防医学 | 157752篇 |
眼科学 | 47949篇 |
药学 | 154419篇 |
4篇 | |
中国医学 | 4068篇 |
肿瘤学 | 109840篇 |
出版年
2018年 | 20453篇 |
2016年 | 17774篇 |
2015年 | 20231篇 |
2014年 | 27859篇 |
2013年 | 42625篇 |
2012年 | 57238篇 |
2011年 | 61289篇 |
2010年 | 36623篇 |
2009年 | 34466篇 |
2008年 | 58495篇 |
2007年 | 62791篇 |
2006年 | 63851篇 |
2005年 | 61837篇 |
2004年 | 59965篇 |
2003年 | 58061篇 |
2002年 | 56686篇 |
2001年 | 93667篇 |
2000年 | 95901篇 |
1999年 | 81124篇 |
1998年 | 23189篇 |
1997年 | 20810篇 |
1996年 | 20992篇 |
1995年 | 20005篇 |
1994年 | 18844篇 |
1993年 | 17477篇 |
1992年 | 65630篇 |
1991年 | 64559篇 |
1990年 | 63769篇 |
1989年 | 61716篇 |
1988年 | 56944篇 |
1987年 | 56444篇 |
1986年 | 53331篇 |
1985年 | 51191篇 |
1984年 | 38424篇 |
1983年 | 32985篇 |
1982年 | 19772篇 |
1981年 | 17630篇 |
1979年 | 36080篇 |
1978年 | 25726篇 |
1977年 | 22034篇 |
1976年 | 20907篇 |
1975年 | 22442篇 |
1974年 | 26751篇 |
1973年 | 25821篇 |
1972年 | 24174篇 |
1971年 | 22583篇 |
1970年 | 20953篇 |
1969年 | 19900篇 |
1968年 | 18596篇 |
1967年 | 16534篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
A Sharma H L Goh N Asokananthan A Bakker G A Stewart H W Mitchell 《The European respiratory journal》2006,27(1):20-28
Mucosal trypsin, a protease-activated receptor (PAR) stimulant, may have an endogenous bronchoprotective role on airway smooth muscle. To test this possibility the effects of lumenal trypsin on airway tone in segments of pig bronchus were tested. Bronchial segments from pigs were mounted in an organ chamber containing Kreb's solution. Contractions were assessed from isovolumetric lumen pressure induced by acetylcholine (ACh) or carbachol added to the adventitia. Trypsin, added to the airway lumen (300 microg x mL(-1)), had no immediate effect on smooth muscle tone but suppressed ACh-induced contractions after 60 min, for at least 3 h. Synthetic activating peptides (AP) for PAR1, PAR2 or PAR3 were without effect, but PAR4 AP caused rapid, weak suppression of contractions. Lumenal thrombin was without effect and did not prevent the effects of trypsin. Effects of trypsin were reduced by N(omega)-nitro-L-arginine methyl ester but not indomethacin. Trypsin, thrombin and PAR4 AP released prostaglandin E2. Adventitially, trypsin, thrombin and PAR4 AP (but not PAR2 AP) relaxed carbachol-toned airways after <3 min. The findings of this study show that trypsin causes delayed and persistent bronchoprotection by interacting with airway cells accessible from the lumen. The signalling mechanism may involve nitric oxide synthase but not prostanoids or protease-activated receptors. 相似文献
92.
93.
Social phobia, fear of negative evaluation and harm avoidance. 总被引:1,自引:0,他引:1
M Faytout J Tignol J Swendsen D Grabot B Aouizerate J P Lépine 《European psychiatry》2007,22(2):75-79
This naturalistic, prospective investigation examined the role of fear of negative evaluation and the personality trait of harm avoidance in the anxiety levels of treated social phobia patients. One hundred and fifty-seven patients with DSM-IV social phobia were assessed before starting treatment and were then followed for up to two years. As expected, greater fear of negative evaluation and higher scores of harm avoidance were associated with greater anxiety at the 6 month follow-up, and harm avoidance remained a significant predictor at 24 months. However, no evidence was found for an interaction between the personality and cognitive variables examined. The findings are discussed in terms of the relative independence of these factors, as well as their potential implications for the treatment of this disorder. 相似文献
94.
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
95.
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
96.
97.
P F Plouin D L Clement H Boccalon J Dormandy I Durand-Zaleski G Fowkes L Norgren T Brown 《International angiology》2003,22(4):333-339
Atherosclerotic renal artery stenosis (ARAS) may cause hypertension, progressive renal failure, and recurrent pulmonary edema. It typically occurs in high risk patients with coexistent vascular disease elsewhere. Most patients with ARAS are likely to die from coronary heart disease or stroke before end-stage renal failure occurs. Recent controlled trials have shown that most patients undergoing angioplasty to treat renovascular hypertension still need antihypertensive agents 6 or 12 months after the procedure. Nevertheless, the number of antihypertensive agents required to control blood pressure adequately is lower following angioplasty than for medication alone. Trials assessing the value of revascularization for preserving renal function or preventing clinical events are only in the early recruitment phase. Revascularization should be undertaken in patients with ARAS and resistant hypertension or heart failure, and probably in those with rapidly deteriorating renal function or with an increase in plasma creatinine levels during angiotensin-converting enzyme inhibition. With or without revascularization, medical therapy using antihypertensive, hypolipidemic and antiplatelet agents is necessary in almost all cases. 相似文献
98.
Is atrial fibrillation an inflammatory disorder? 总被引:2,自引:0,他引:2
I read with great interest the excellent review on the influenceof inflammation in the pathogenesis of atrial fibrillation (AF)by Boos 相似文献
99.
100.
Adriana B Campaner Alessandro Scapinelli Ruy O Machado Roberto E Dos Santos Geni W Beznos Tsutomu Aoki 《Gynecological endocrinology》2006,22(7):395-398
We report a case of a prepubertal girl with juvenile primary hypothyroidism presenting as ovarian cysts and precocious puberty. The 7-year-old female was referred to our clinic because of a pelvic/abdominal mass and vaginal bleeding. Besides these findings, on physical examination we noticed the thyroid gland globally increased and the presence of secondary sexual characteristics. Based upon the clinical profile and investigations, the patient was diagnosed with juvenile primary hypothyroidism due to autoimmune thyroiditis. The cysts and precocious puberty resolved spontaneously after the simple replacement of thyroid hormone. It is important to bear in mind hypothyroidism in cases of girls presenting ovarian cysts and precocious puberty in order to avoid unnecessary surgery on the ovaries. 相似文献