全文获取类型
收费全文 | 2185497篇 |
免费 | 150786篇 |
国内免费 | 3215篇 |
专业分类
耳鼻咽喉 | 31432篇 |
儿科学 | 71616篇 |
妇产科学 | 62167篇 |
基础医学 | 314164篇 |
口腔科学 | 61437篇 |
临床医学 | 189565篇 |
内科学 | 420188篇 |
皮肤病学 | 47323篇 |
神经病学 | 168435篇 |
特种医学 | 86163篇 |
外国民族医学 | 564篇 |
外科学 | 335208篇 |
综合类 | 45236篇 |
现状与发展 | 2篇 |
一般理论 | 552篇 |
预防医学 | 156695篇 |
眼科学 | 49987篇 |
药学 | 170626篇 |
8篇 | |
中国医学 | 4904篇 |
肿瘤学 | 123226篇 |
出版年
2018年 | 21425篇 |
2016年 | 18603篇 |
2015年 | 21133篇 |
2014年 | 28904篇 |
2013年 | 43355篇 |
2012年 | 59419篇 |
2011年 | 63442篇 |
2010年 | 37508篇 |
2009年 | 35215篇 |
2008年 | 60395篇 |
2007年 | 65133篇 |
2006年 | 66134篇 |
2005年 | 64072篇 |
2004年 | 61549篇 |
2003年 | 59578篇 |
2002年 | 58142篇 |
2001年 | 107260篇 |
2000年 | 110123篇 |
1999年 | 92661篇 |
1998年 | 24809篇 |
1997年 | 22021篇 |
1996年 | 22141篇 |
1995年 | 20922篇 |
1994年 | 19446篇 |
1993年 | 18141篇 |
1992年 | 72447篇 |
1991年 | 70494篇 |
1990年 | 69559篇 |
1989年 | 67234篇 |
1988年 | 61869篇 |
1987年 | 60462篇 |
1986年 | 57434篇 |
1985年 | 54365篇 |
1984年 | 40070篇 |
1983年 | 34407篇 |
1982年 | 19735篇 |
1981年 | 17430篇 |
1979年 | 37075篇 |
1978年 | 25544篇 |
1977年 | 22430篇 |
1976年 | 20406篇 |
1975年 | 22780篇 |
1974年 | 26666篇 |
1973年 | 25785篇 |
1972年 | 24618篇 |
1971年 | 22978篇 |
1970年 | 21239篇 |
1969年 | 20582篇 |
1968年 | 18865篇 |
1967年 | 16706篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
J Masata A Martan K Svabik P Drahoradova M Pavlikova 《Ultrasound in obstetrics & gynecology》2006,28(2):221-228
OBJECTIVES: To evaluate changes in the mobility of the whole urethra, in the proximal urethra (funneling) and in the thickness of the urinary bladder wall, after a successful tension-free vaginal tape (TVT) procedure. METHODS: This prospective longitudinal study included 52 women with urodynamically confirmed stress urinary incontinence who had undergone a successful TVT procedure. Ultrasound examination was performed before the TVT procedure and at a median of 3 (range, 3-6) months after surgery. For all women, the changes to the urethra and urinary bladder induced by surgery were examined. For three mobility groups (low, intermediate and high urethral mobility before surgery) we compared the changes induced by the operation and the typical position and mobility of the tape. RESULTS: The position of the urethra at rest was not influenced by surgery. The operation significantly decreased the mobility of all parts of the urethra during Valsalva. The absolute changes of the vector of the urethral movement differed according to the mobility group (average decrease, 6 mm; decrease for women with low, intermediate and high mobility, respectively, 2-3 mm, 4-6 mm and 9 mm). The change in relative mobility was the same in all groups. The operation decreased funneling (width and depth) during maximal Valsalva. After surgery there was an increase in the thickness of the bladder wall (by 0.64 and 0.73 mm, respectively, at the anterior part and trigone). CONCLUSIONS: A successful TVT procedure did not influence the position of the urethra at rest but significantly decreased the mobility of the urethra during Valsalva and also decreased funneling at maximal Valsalva. 相似文献
92.
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
93.
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
94.
95.
96.
M. C. van den Heuvel K. P. de Jong M. Boot M. J. H. Slooff S. Poppema A. S. H. Gouw 《American journal of transplantation》2006,6(11):2660-2671
The finer branches of the biliary tree (FBBT) contain a regenerative compartment. We hypothesized that preservation of the FBBT together with its microvasculature will lead to recovery of biliary damage and prolonged preservation of bile ductules during the development of chronic liver allograft rejection. The interlobular bile ducts, portal bile ductules and extraportal biliary cells with and without microvessels were studied in sequential biopsies in five patients who fulfilled the Banff criteria of early chronic rejection (CR) (imminence group). Biopsies of CR patients (n = 12) served as controls. Biopsies were double immunostained with CD34 (microvessels) and cytokeratin 7 (biliary structures). Proliferation and proangiogenic activity were assessed with Ki67 and VEGF-A immunostaining. Severe damage of bile ducts in the imminence group did not progress to significant bile duct loss. This was associated with a high proliferative activity in all biliary structures and preservation of the microvascular compartment. VEGF-A expression was increased in all but the reperfusion biopsies. In conclusion, both regenerative activity of the FBBT and an intact microvascular compartment are associated with less damage of the biliary tree and could therefore be prerequisites for biliary regeneration. 相似文献
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.
99.
C Edward Hoffler Kurt D Hankenson Joshua D Miller Sukhinderdeep K Bilkhu Steven A Goldstein 《Journal of orthopaedic research》2006,24(8):1687-1698
To understand in situ behavior of osteocytes, we characterized a model of osteocytes in their native bone matrix and demonstrated real-time biologic activity of osteocytes while bending the bone matrix. Using 43 male Sprague-Dawley rats, dumbbell-shaped explants were harvested from stainless steel femoral implants after 6-12 weeks and incubated in culture medium or fixed. Sixteen specimens were used to determine bone volume density (BV/TV), volumetric bone mineral density (BMD) and histology for different implantation periods. Osteocyte viability was evaluated by L-lactate dehydrogenase (LDH) activity in 12 cultured explants. Confocal microscopy was used to assess tracer diffusion in three explants and changes in osteocyte pH of a mechanically loaded explant. From 6 to 12 weeks, explant BV/TV and volumetric BMD trended up 92.5% and 101%, respectively. They were significantly and highly correlated. Tissues were uniformly intramembranous and all bone cell types were present. Explants maintained LDH activity through culture day 8. Diffusion at 200 microM was limited to 1,209 Da. Explants appeared capable of reproducing complex bone biology. This model may be useful in understanding osteocyte mechanotransduction in the context of a physiologically relevant bone matrix. 相似文献
100.
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