全文获取类型
收费全文 | 13420篇 |
免费 | 1203篇 |
国内免费 | 41篇 |
专业分类
耳鼻咽喉 | 178篇 |
儿科学 | 371篇 |
妇产科学 | 331篇 |
基础医学 | 1848篇 |
口腔科学 | 757篇 |
临床医学 | 1155篇 |
内科学 | 3122篇 |
皮肤病学 | 287篇 |
神经病学 | 1146篇 |
特种医学 | 512篇 |
外科学 | 1902篇 |
综合类 | 85篇 |
一般理论 | 5篇 |
预防医学 | 1090篇 |
眼科学 | 242篇 |
药学 | 725篇 |
中国医学 | 42篇 |
肿瘤学 | 866篇 |
出版年
2023年 | 65篇 |
2022年 | 177篇 |
2021年 | 340篇 |
2020年 | 232篇 |
2019年 | 370篇 |
2018年 | 464篇 |
2017年 | 342篇 |
2016年 | 368篇 |
2015年 | 402篇 |
2014年 | 506篇 |
2013年 | 603篇 |
2012年 | 865篇 |
2011年 | 833篇 |
2010年 | 554篇 |
2009年 | 449篇 |
2008年 | 668篇 |
2007年 | 749篇 |
2006年 | 645篇 |
2005年 | 616篇 |
2004年 | 524篇 |
2003年 | 478篇 |
2002年 | 419篇 |
2001年 | 346篇 |
2000年 | 318篇 |
1999年 | 342篇 |
1998年 | 121篇 |
1997年 | 124篇 |
1996年 | 98篇 |
1995年 | 92篇 |
1994年 | 91篇 |
1993年 | 89篇 |
1992年 | 229篇 |
1991年 | 208篇 |
1990年 | 174篇 |
1989年 | 197篇 |
1988年 | 168篇 |
1987年 | 146篇 |
1986年 | 155篇 |
1985年 | 151篇 |
1984年 | 109篇 |
1983年 | 91篇 |
1982年 | 50篇 |
1981年 | 56篇 |
1979年 | 72篇 |
1978年 | 59篇 |
1976年 | 45篇 |
1975年 | 50篇 |
1974年 | 40篇 |
1973年 | 54篇 |
1972年 | 46篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
There has been a recent increase in reported cases of fungal sinusitis. This may be due to better awareness and improved histopathological methods as well as increasing numbers of immunologically compromised patients. We present a case of mycotic sinusitis in an immunocompetent individual to emphasize the clinical features of this disease. The pathology and microbiology are analyzed and a management protocol is discussed. 相似文献
992.
C Suarez Nieto J Gomez Martinez P Barthe Garcia J L Llorente Pendas 《Clinical otolaryngology and allied sciences》1989,14(2):141-145
The local and general complications in a series of 122 patients treated surgically for carcinoma of the tonsillar region are reported. Eighty-five of these patients were submitted to reconstruction with local or distant flaps, and in the remaining 37 patients primary closure was achieved. 28.2% of the flaps underwent marginal necrosis, and 11.8% total necrosis. Infection and the proportion of general complications were significantly higher in those patients submitted to reconstruction with flaps, whereas fistulae, necrosis of the cervical skin, rupture of the carotid artery and common general complications were not. Significant differences were not observed with respect to viability nor to complications between the different types of flaps, so that the choice of flaps should be based exclusively on other properties inherent in each flap. 相似文献
993.
994.
995.
996.
Elizabeth Garcia Gustavo Aristizabal Catalina Vasquez Carlos E. Rodriguez-Martinez Olga L. Sarmiento Claudia L. Satizabal 《Pediatric allergy and immunology》2008,19(4):307-314
This cross‐sectional study of children aged 6–7 years and adolescents aged 13–14 years in Bogotá, Colombia, assessed the prevalence of asthma symptoms and their associations with dietary, health, and behavioral habits. This study is part of the International Study of Asthma and Allergies in Childhood (ISAAC)‐phase III. Asthma prevalence among the children was assessed using a parental self‐administered written questionnaire (WQ), and among adolescents using a WQ together with a video questionnaire (VQ). Associations were estimated with bivariate and multivariate analysis. The study found that the 6–7 year age‐group were more likely to report current asthma symptoms than the 13–14 year age‐group (10.4% [WQ] vs. 8.6% [WQ] and 8.0% [VQ], respectively). Factors associated with current asthma symptoms among the 6–7 year age‐group included higher maternal education (OR = 1.7, [95% CI 1.2–2.6], p = 0.007), a cat in the home during the last year (OR = 1.5, [95% CI 1.0–2.3], p = 0.036), watching TV 1–2 hours/day (OR = 2.1, [95% CI 1.2–3.9], p = 0.013), and medication with acetaminophen in the first and most recent year of life (OR = 1.8, [95% CI 1.3–2.4], p < 0.001; OR = 2.2, [95% CI 1.7–2.8], p < 0.001, respectively) or antibiotics in the first year of life (OR = 1.9, [95% CI 1.4–2.5], p < 0.001). Among the 13–14 year age‐group, factors associated with current asthma symptoms included medication with acetaminophen during the last year (OR = 1.8, [95% CI 1.4–2.3], p < 0.001); cereal, milk, and fruit consumption 3 or more times weekly (OR = 1.5, [95% CI 1.1–1.9], p = 0.010; OR = 0.8, [95% CI 0.6–1.0], p = 0.046; OR = 0.6, [95% CI 0.4–1.0], p = 0.031, respectively). Overall, compared with that in other Latin American centers, asthma prevalence in Bogotá is close the lower estimates. However, associations with dietary, health, and behavioral habits need further study to assess their complex relationship with asthma. 相似文献
997.
P.-M. Martin C. Cifuentes-Diaz M. Garcia L. Goutebroze J.-A. Girault 《Revue neurologique》2008,164(12):1057-1062
Myelination was a major step in the evolution of the nervous system. Appearing first in jaw fish, myelination allows the fast and secure propagation of action potentials at a low energetic cost, and without exaggerated increase in axonal diameter. In the peripheral nervous system of mammals, myelination results from the tight interactions between Schwann cells and axons, leading to the formation of highly differentiated domains along the axon. The molecular determinants of these interactions are starting to be well identified. Their understanding provides a precise framework to interpret the defects, which occur in pathological circumstances. This review summarizes the present state of knowledge concerning axoglial interactions in peripheral nerves. 相似文献
998.
Luis Hernandez‐Garcia Alberto L. Vazquez Daniel B. Rowe 《Magnetic resonance in medicine》2009,62(6):1597-1608
Cerebral blood flow‐dependent phase differences between tagged and control arterial spin labeling images are reported. A biophysical model is presented to explain the vascular origin of this difference. Arterial spin labeling data indicated that the phase difference is largest when the arterial component of the signals is preserved but is greatly reduced as the arterial contribution is suppressed by postinversion delays or flow‐crushing gradients. Arterial vasculature imaging by saturation data of activation and hypercapnia conditions showed increases in phase accompanying blood flow increases. An arterial spin labeling functional magnetic resonance imaging study yielded significant activation by magnitude‐only, phase‐only, and complex analyses when preserving the whole arterial spin labeling signal. After suppression of the arterial signal by postinversion delays, magnitude‐only and complex models yielded similar activation levels, but the phase‐only model detected nearly no activation. When flow crushers were used for arterial suppression, magnitude‐only activation was slightly lower and fluctuations in phase were dramatically higher than when postinversion delays were used. Although the complex analysis performed did not improve detection, a simulation study indicated that the complex‐valued activation model exhibits combined magnitude and phase detection power and thus maximizes sensitivity under ideal conditions. This suggests that, as arterial spin labeling imaging and image correction methods develop, the complex‐valued detection model may become helpful in signal detection. Magn Reson Med, 2009. © 2009 Wiley‐Liss, Inc. 相似文献
999.
Lobular carcinoma in situ (LCIS) has uncertain malignant potential; biologic markers that will identify patients at risk for a poor clinical outcome have been sought actively. Amplification of the c-erbB-2 protooncogene has been correlated with poor prognosis in invasive mammary carcinoma, and immunohistochemical evaluation for expression of the oncogene protein has been correlated with gene amplification. The authors retrospectively evaluated 62 cases of lobular neoplasia for expression of the c-erbB-2 gene product on formalin-fixed, deparaffinized sections, using two monoclonal anti-erbB-2 (p185) antibodies (c-neu Ab3 and m-erb) and one polyclonal anti-erbB-2 antibody (pAb 1) by the avidin-biotin-peroxidase method. All 62 cases were negative with the pAb 1 antibody; one of 62 cases was weakly positive with the c-neu Ab3 in a membranous pattern. Expression of c-erbB-2 gene product was identified on adjacent invasive ductal carcinoma in one case and in adjacent ductal carcinoma in situ in another. None of 15 cases if infiltrating lobular carcinoma was positive with either of the two anti-c-erbB-2 antibodies. Strong positivity was found on benign epithelium in one case, demonstrating epitheliosis. In summary, evidence of expression of the c-erbB-2 gene product was found in one of 57 cases of LCIS and none of 15 cases of invasive lobular carcinoma. This suggests that, in contrast to reported data concerning intraductal and invasive ductal carcinoma, c-erbB-2 oncogene amplification and/or overexpression does not play a significant role in the progression of lobular breast neoplasia. 相似文献
1000.
Glandular schwannoma is an infrequent tumor, especially in the pediatric age group. We report a case in which the tumor developed in the retroperitoneum of a 17-month-old girl without stigmata of Von Recklinghausen's disease (VRD). She presented a local recurrence and bone and pulmonary metastases at 11, 23, and 30 months, respectively, after tumor resection. The pathologic findings in the original tumor did not permit us to predict its potential to metastasize. The ultrastructural characteristics of both glandular and schwannian elements are described. The rarity of this neoplasia in children and the absence of histological parameters of aggressiveness are emphasized. 相似文献