全文获取类型
收费全文 | 863835篇 |
免费 | 70609篇 |
国内免费 | 1839篇 |
专业分类
耳鼻咽喉 | 12823篇 |
儿科学 | 24767篇 |
妇产科学 | 25132篇 |
基础医学 | 124517篇 |
口腔科学 | 25539篇 |
临床医学 | 75473篇 |
内科学 | 164877篇 |
皮肤病学 | 17001篇 |
神经病学 | 70232篇 |
特种医学 | 35243篇 |
外国民族医学 | 171篇 |
外科学 | 136327篇 |
综合类 | 24610篇 |
现状与发展 | 2篇 |
一般理论 | 263篇 |
预防医学 | 66990篇 |
眼科学 | 20528篇 |
药学 | 64823篇 |
中国医学 | 1597篇 |
肿瘤学 | 45368篇 |
出版年
2018年 | 7378篇 |
2015年 | 7761篇 |
2014年 | 11159篇 |
2013年 | 16837篇 |
2012年 | 22804篇 |
2011年 | 23926篇 |
2010年 | 13908篇 |
2009年 | 13094篇 |
2008年 | 22640篇 |
2007年 | 24688篇 |
2006年 | 24567篇 |
2005年 | 24206篇 |
2004年 | 23763篇 |
2003年 | 22871篇 |
2002年 | 21989篇 |
2001年 | 35883篇 |
2000年 | 36521篇 |
1999年 | 30936篇 |
1998年 | 9243篇 |
1997年 | 8561篇 |
1996年 | 8484篇 |
1995年 | 8020篇 |
1994年 | 7744篇 |
1992年 | 26686篇 |
1991年 | 26128篇 |
1990年 | 25640篇 |
1989年 | 24695篇 |
1988年 | 23243篇 |
1987年 | 22893篇 |
1986年 | 21758篇 |
1985年 | 21115篇 |
1984年 | 16398篇 |
1983年 | 14010篇 |
1982年 | 8867篇 |
1981年 | 8211篇 |
1980年 | 7682篇 |
1979年 | 16757篇 |
1978年 | 12128篇 |
1977年 | 10193篇 |
1976年 | 9337篇 |
1975年 | 10152篇 |
1974年 | 12653篇 |
1973年 | 12145篇 |
1972年 | 11546篇 |
1971年 | 10690篇 |
1970年 | 10229篇 |
1969年 | 9916篇 |
1968年 | 8906篇 |
1967年 | 8246篇 |
1966年 | 7666篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
Median cervical cysts are congenital anomalies arising from remaining thyroglossal duct epithelium. A major problem in the surgical treatment of these cysts is the high frequency of recurrence. Embryonic considerations indicate an important causal role for the hyoid bone in these recurrences. We studied the relationship between operative techniques and the number of recurrences in 36 patients treated in our hospital. Fourteen patients sent from other hospitals had a recurrent fistula; in thirteen cases the hyoid bone was still in place. All patients who had the central part of the hyoid bone excised were cured. In 14 patients without adequate excisions of the hyoid bone we found four recurrences. To prevent recurrence a total excision of thyroglossal duct epithelium is necessary. 相似文献
102.
103.
A novel hybridoma antibody (PASE/4LJ) to human prostatic acid phosphatase suitable for immunohistochemistry 总被引:2,自引:0,他引:2
A M Haines S E Larkin A P Richardson R W Stirling E Heyderman 《British journal of cancer》1989,60(6):887-892
A murine monoclonal antibody PASE/4LJ to prostatic acid phosphatase (PAP) was used to immunostain a wide variety of sections of benign and malignant tissues (654 blocks). Non-neoplastic adult and fetal prostatic glands, primary and metastatic prostatic carcinomas, and scattered cells in prostatic and penile urethra were positive. Rat, dog and rabbit prostates were negative. Nine of 400 tumours of non-prostatic origin showed some positivity: 6/36 carcinoids, 1/9 islet cell tumours, 1/55 ovarian adenocarcinomas (serous) and one carcinosarcoma of the lung (epithelial portion). Positive staining was seen in islet cells in 4/5 specimens of normal pancreas, and in 4/9 blocks of normal pancreas surrounding a pancreatic tumour. Loops of Henle, maculae densae, and distal tubules in 10/10 fetal and 2/9 adult kidneys were also positive, with proximal tubules and collecting ducts negative. All other 159 blocks of non-neoplastic adult and fetal tissues were negative. The antibody was also affinity purified from ascitic fluid, and shown not to inhibit the enzyme activity of prostatic acid phosphatase. 相似文献
104.
105.
A. HAZIOT I. KATZ G. W. RONG X. Y. LIN J. SILVER & S. M. GOYERT 《Scandinavian journal of immunology》1997,46(3):242-245
Membrane-bound CD14 acts as a receptor for lipopolysaccharide (LPS) on monocytes/macrophages and neutrophils. Studies have suggested that the activation of monocytes/macrophages by the binding of LPS to membrane-bound CD14 may require the association of a signal-transducing molecule with membrane-bound CD14. The observation that non-CD14 expressing cells, such as endothelial cells, can nevertheless be activated by a complex of LPS and a soluble form of CD14 (sCD14) suggests that the receptor for this complex may be identical to the signal transducing molecule associated with membrane-bound CD14. The studies described show that two CD14-specific MoAb are able to block the LPS-induced activation of endothelial cells but do not affect the response of monocytes to LPS. This suggests that the interaction of the sCD14:LPS complex with endothelial cells is distinct from the interaction of membrane-bound CD14 with its putative signal-transducing molecule. 相似文献
106.
Most prosthetic joint infections (PJI) are due to wound contamination at the time of surgery. Some infections occur due to the hematogenous spread of bacteria from distant sites of infection. A review of the literature fails to associate PJI with transient bacteremias from invasive dental procedures. Several authors have described conditions which, they believe, render patients with prosthetic joints more at risk for infection. Prosthetic joint patients with these "high risk" conditions have the same types of infecting organisms as other patients with PJI. This indicates that the infecting bacteria are from wound contamination or distant sites of infection and not related to dental procedure bacteremias. Based on this review, antibiotic prophylaxis is not indicated for patients with prosthetic joints when receiving invasive dental procedures, since there is no proven benefit and there are known risks involved with the use of antibiotics. However, the American Dental Association (ADA) and the American Academy of Orthopaedic Surgeons (AAOS), in an advisory statement, suggest prophylaxis for "high risk" patients. The ADA and AAOS recommend a single dose of amoxicillin, cephradine, or clindamycin when prophylaxis is selected. The dentist is ultimately responsible for making treatment recommendations for his or her patients. 相似文献
107.
108.
Increase in Power through Multivariate Analyses 总被引:6,自引:0,他引:6
Power to detect genetic and environmental influences increases not only with sample size but also with the number of measurements through longitudinal and/or multivariate designs, if those measurements correlate with each other. Power simulations are presented for uni- through quadrivariate cases, with differing genetic and environmental parameters. Even though subject attrition is a problem for most longitudinal studies, the gain in power available may more than make up for this shortcoming in many situations. In terms of planning studies to examine genetic and environmental influences, power calculations should not only consider sample size but number of measurements on particular phenotypes and their intercorrelations. 相似文献
109.
Plasmid DNA encoding transforming growth factor-beta1 suppresses chronic disease in a streptococcal cell wall-induced arthritis model. 总被引:6,自引:0,他引:6 下载免费PDF全文
X Y Song M Gu W W Jin D M Klinman S M Wahl 《The Journal of clinical investigation》1998,101(12):2615-2621
Transforming growth factor beta is a potent immunomodulator with both pro- and antiinflammatory activities. Based on its immunosuppressive actions, exogenous TGF-beta has been shown to inhibit autoimmune and chronic inflammatory diseases. To further explore the potential therapeutic role of TGF-beta, we administered a plasmid DNA encoding human TGF-beta1 intramuscularly to rats with streptococcal cell wall-induced arthritis. A single dose of 300 microg plasmid DNA encoding TGF-beta1, but not vector DNA, administered at the peak of the acute phase profoundly suppressed the subsequent evolution of chronic erosive disease typified by disabling joint swelling and deformity (articular index = 8.17+/-0. 17 vs. 1.25+/-0.76, n = 6, day 26, P < 0.01). Moreover, delivery of the TGF-beta1 DNA even as the chronic phase commenced virtually eliminated subsequent inflammation and arthritis. Both radiologic and histopathologic as well as molecular evidence supported the marked inhibitory effect of TGF-beta1 DNA on synovial pathology, with decreases in the inflammatory cell infiltration, pannus formation, cartilage and bone destruction, and the expression of proinflammatory cytokines that characterize this model. Increases in TGF-beta1 protein were detected in the circulation of TGF-beta1 DNA-treated animals, consistent with the observed therapeutic effects being TGF-beta1 dependent. These observations provide the first evidence that gene transfer of plasmid DNA encoding TGF-beta1 provides a mechanism to deliver this potent cytokine that effectively suppresses ongoing inflammatory pathology in arthritis. 相似文献
110.
This study examines the relationships between patient characteristics and surrogate decision maker characteristics on surrogates' preferences for life-sustaining treatments. Caucasian and African-American caregivers and noncaregivers (n=110) responded to a vignette involving a medical crisis in a hospitalized older man who suffered cardiac arrest, one of the most common causes of death among older Americans. This man was described as either a cognitively intact or moderately demented family member. Participants made decisions regarding cardiopulmonary resuscitation (CPR), CPR and ventilation, and CPR and tube feeding. Analyses followed a 2 (cognitive status) 2 (caregiving status) 2 (racial background) analysis of covariance design, with education and income used as covariates. In general, participants were less likely to initiate life-sustaining treatments in demented patients. Caucasian caregivers were less likely to initiate CPR and ventilation and CPR and tube feeding. Results indicate that characteristics of the patient and the interplay between cultural issues and experience with caregiving affect surrogate judgements regarding life-sustaining treatments. 相似文献