首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   157505篇
  免费   33393篇
  国内免费   2407篇
耳鼻咽喉   5208篇
儿科学   5643篇
妇产科学   2579篇
基础医学   4226篇
口腔科学   1674篇
临床医学   27570篇
内科学   48611篇
皮肤病学   7473篇
神经病学   15460篇
特种医学   6611篇
外国民族医学   1篇
外科学   42646篇
综合类   548篇
现状与发展   72篇
一般理论   14篇
预防医学   7886篇
眼科学   3539篇
药学   1430篇
中国医学   13篇
肿瘤学   12101篇
  2024年   514篇
  2023年   4828篇
  2022年   1264篇
  2021年   3256篇
  2020年   6133篇
  2019年   2337篇
  2018年   7583篇
  2017年   7488篇
  2016年   8531篇
  2015年   8549篇
  2014年   15702篇
  2013年   15941篇
  2012年   5881篇
  2011年   5924篇
  2010年   10605篇
  2009年   14444篇
  2008年   6128篇
  2007年   4422篇
  2006年   6832篇
  2005年   4067篇
  2004年   3323篇
  2003年   2284篇
  2002年   2373篇
  2001年   4013篇
  2000年   3214篇
  1999年   3387篇
  1998年   3741篇
  1997年   3552篇
  1996年   3426篇
  1995年   3281篇
  1994年   2017篇
  1993年   1616篇
  1992年   1558篇
  1991年   1590篇
  1990年   1220篇
  1989年   1316篇
  1988年   1151篇
  1987年   962篇
  1986年   1024篇
  1985年   842篇
  1984年   654篇
  1983年   610篇
  1982年   578篇
  1981年   460篇
  1980年   412篇
  1979年   400篇
  1978年   417篇
  1977年   450篇
  1975年   336篇
  1972年   378篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
991.
992.
Dactylolysis spontanea is an idiopathic condition affecting the fifth toe, and sometimes other toes, that is frequently bilateral, with lesions in different stages. Between 1977 and 1999, a total 6000 radiographic studies of the feet were reviewed in a mainly African American population in Chicago, Illinois. After an initial screening based on the Cole criteria, 581 patients were selected and re-examined, and amplification techniques were performed. After reviewing the complementary exams, 102 patients were diagnosed with dactylolysis spontanea or ainhum. Soft-tissue constriction was the most frequently presented radiological sign on the initial screening. Kurtosis at the digit plantar fold and marked rotation of the fifth toe were normal findings in asymptomatic patients. Demographics, comorbidities, and radiological findings were analyzed in the selected population. Associated diseases occurring in these patients appeared to have no specific etiologic correlation with ainhum. African Americans and the dark-skinned population are affected exclusively by this condition, presumably due to the fibrogenic tendency of these individuals. Early diagnosis and accurate staging of ainhum are facilitated by radiological examination of the feet. The findings suggest that this condition is underdiagnosed and overlooked because its low prevalence and variable clinical presentations that might mimic more common etiologies, including localized trauma.  相似文献   
993.
Recent steps to prevent neonatal sepsis due to group B Streptococcal infection have lowered the attack rate from this organism, but may not have lowered overall sepsis rates. Mortality from sepsis stills remains between 20 and 40% and is probably so high due to the immunological immaturity of the newborn. Although antibiotics remain the mainstay for treatment, adjunctive therapies aimed at improving the immunological integrity of the neonatal patient have a role in treatment and may improve outcomes. We discuss several adjunctive therapies, along with the physiologic rationale for their use, and discuss an approach for their inclusion in therapy for neonatal sepsis.  相似文献   
994.
BACKGROUND: Hidradenoma papilliferum is an uncommon benign tumor that is located almost exclusively in the vulvar and anal areas. It is usually very small and asymptomatic, and to make a correct diagnosis is clinically very difficult. Occasionally the tumor becomes elevated to form a reddish brown papillary mass, and the surface ulcerates, which may erroneously suggest malignancy. OBJECTIVE: We report a case of a large, perianal hidradenoma papilliferum with suspected malignancy in a young Japanese female. RESULTS: A 22-year-old female had been aware of a perianal nodule for approximately 1 year. Examination of the perianal area revealed a wide pedunculated, reddish nodule with several white maculae. It was ulcerated and bleeding, 2.0 x 1.2 x 0.8 cm in size, and located in the 3 o'clock position. The nodule was totally excised with a narrow margin. The histopathologic diagnosis was hidradenoma papilliferum. No recurrence was observed for 23 months. CONCLUSION: When dermatologists encounter tumors of the anogenital area of adult females, it is important to keep hidradenoma papilliferum in mind as the differential diagnosis. Dermatologists should recognize that the tumor is benign, eliminating the need for wide resection.  相似文献   
995.
BACKGROUND: Basal cell carcinoma shows a wide spectrum of clinical and histologic appearances. A distinct tumor variant with follicular infundibulocystic differentiation is recognized, and there are only a few reports on its clinical presentation and management. OBJECTIVE: To report a case of multiple infundibulocystic basal cell carcinomas with a unique unilateral presentation. METHODS: A clinical history was obtained. Photographs were taken, and punch biopsies were performed. RESULTS: An 83-year-old Caucasian female presented with multiple unilateral, asymptomatic, skin-colored, dome-shaped papules around the right mouth for 11 years without apparent change. Punch biopsies revealed findings typical of infundibulocystic basal cell carcinoma. CONCLUSIONS: A patient with clinically indolent multiple unilateral infundibulocystic basal cell carcinomas is described. Given the location of these multiple lesions, standard treatment modalities for basal cell carcinomas would have significant cosmetic and functional implications. A management approach with clinical follow-up and surgical intervention only for changing lesions is discussed.  相似文献   
996.
997.
998.
999.
1000.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号