全文获取类型
收费全文 | 2179068篇 |
免费 | 168515篇 |
国内免费 | 5187篇 |
专业分类
耳鼻咽喉 | 28915篇 |
儿科学 | 73429篇 |
妇产科学 | 62063篇 |
基础医学 | 312907篇 |
口腔科学 | 60028篇 |
临床医学 | 197259篇 |
内科学 | 427697篇 |
皮肤病学 | 50427篇 |
神经病学 | 177308篇 |
特种医学 | 83043篇 |
外国民族医学 | 752篇 |
外科学 | 324564篇 |
综合类 | 51728篇 |
现状与发展 | 3篇 |
一般理论 | 819篇 |
预防医学 | 172553篇 |
眼科学 | 49924篇 |
药学 | 155079篇 |
4篇 | |
中国医学 | 4866篇 |
肿瘤学 | 119402篇 |
出版年
2019年 | 17095篇 |
2018年 | 24285篇 |
2017年 | 18666篇 |
2016年 | 21175篇 |
2015年 | 23722篇 |
2014年 | 33238篇 |
2013年 | 50127篇 |
2012年 | 67168篇 |
2011年 | 71388篇 |
2010年 | 42216篇 |
2009年 | 40147篇 |
2008年 | 66298篇 |
2007年 | 70215篇 |
2006年 | 71141篇 |
2005年 | 68700篇 |
2004年 | 66183篇 |
2003年 | 63282篇 |
2002年 | 61104篇 |
2001年 | 105598篇 |
2000年 | 108225篇 |
1999年 | 90173篇 |
1998年 | 25506篇 |
1997年 | 23024篇 |
1996年 | 23057篇 |
1995年 | 22046篇 |
1994年 | 20220篇 |
1993年 | 18920篇 |
1992年 | 69443篇 |
1991年 | 66952篇 |
1990年 | 64923篇 |
1989年 | 62172篇 |
1988年 | 56754篇 |
1987年 | 56285篇 |
1986年 | 52563篇 |
1985年 | 50367篇 |
1984年 | 38162篇 |
1983年 | 32199篇 |
1982年 | 19562篇 |
1981年 | 17466篇 |
1979年 | 34398篇 |
1978年 | 24480篇 |
1977年 | 20489篇 |
1976年 | 19332篇 |
1975年 | 20068篇 |
1974年 | 24328篇 |
1973年 | 23434篇 |
1972年 | 21735篇 |
1971年 | 19992篇 |
1970年 | 18888篇 |
1969年 | 17491篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
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
102.
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
103.
104.
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
105.
Prof. Dr. C. Voigt 《Der Unfallchirurg》2006,109(4):313-324
A fall onto the hand can be followed by ligament ruptures, bone fractures or dislocated fractures of the carpus. The diagnosis is based on history, clinical evaluation, and X-ray examination in two perpendicular planes, followed if necessary by CT scan or MRI scan. Lesions of the scapholunate ligaments cannot be definitely excluded except by arthroscopy. As well as fractures of the carpometacarpal joints, fractures involving the ring structure of the carpus or ligament ruptures between carpal bones are frequently observed, and these lead to significantly impaired biomechanics. The prognosis is poor. The discontinuity of the ring must be repaired by means of osteosynthesis and/or suturing ligaments, with the carpal bones held in place by temporary arthrodesis using K-wires. Dislocation in this region requires rapid realignment, as untreated perilunate dislocation or dislocation of the lunate bone will lead to serious secondary damage, which can only be treated by salvage operations involving loss of function. Inappropriate treatment of an injury to the heel of the hand can lead to carpal collapse. 相似文献
106.
107.
Chest injuries can be sustained in isolation or in association with multiple injuries. Life-threatening complications may ensue because organs that are vital to survival of the organism are situated within the thoracic cavity. These complications include airway obstruction, tension pneumothorax, wide open pneumothorax, flail chest, cardiac tamponade and massive hemothorax. The mortality of patients hospitalized with chest injury can be as high as 10%. Clinical examination and awareness of the possibility of other injuries (high level of suspicion) are essential, and standard chest X-ray, ultrasound and thoracic computed tomography may also be needed for the diagnosis. The first part of this serial paper on the management of chest injuries focuses on anatomical aspects, pathophysiology and symptoms, but mainly on the indications for the standard diagnostic procedures and further high-tech examinations. 相似文献
108.
Kevin L Taylor Rhonda K Oates Ron Grane Douglas W Leaman Ernest C Borden Daniel J Lindner 《Journal of interferon & cytokine research》2006,26(5):353-361
Interferon-alpha (IFN-alpha) has proved effective in the treatment of hemangiomas, hemangioblastomas, and Kaposi's sarcoma. To investigate the ability of IFNs to inhibit angiosarcoma, we used two transformed murine endothelial cell lines that form angiosarcomas in vivo. SVR and MS1-VEGF cell lines express oncogenic H-ras or vascular endothelial growth factor (VEGF), respectively. IFN-alpha1,8, which is active against murine and human cells, inhibited SVR and MS1-VEGF proliferation in vitro by 40% at 10(3) U/mL (p = 0.028). In vivo, IFN-alpha1,8 inhibited SVR tumor volume by 71% (p = 0.047) and MS1-VEGF volume by 79% (p = 0.003). Tumor-induced angiogenesis was decreased in SVR tumors by 52% (p = 0.005) and in MS1-VEGF tumors by 58% (p = 0.001). Sera from IFN-alpha1,8-treated mice bearing either SVR or MS1-VEGF tumors demonstrated a 5-fold increase in IP-10/CXCL10 (p = 0.001), an IFN-induced antiangiogenic protein. Both recombinant IP-10 and IFN-alpha1,8 inhibited human umbilical vein endothelial cell (HUVEC) vessel formation in the fibrin gel assay, a three-dimensional culture model of angiogenesis, by 56% at 25 ng/mL and 50% at 1.2 ng/mL, respectively (p < 0.001). An IP-10 blocking antibody restored vessel formation to 80% of untreated controls (p = 0.001). Given the magnitude of the in vivo response, these data suggested that the antitumor effects of IFN-alpha1,8 were likely mediated through angiogenesis inhibition rather than solely by direct inhibition of tumor cell proliferation. 相似文献
109.
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
110.