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   151017篇
  免费   32547篇
  国内免费   2399篇
耳鼻咽喉   5187篇
儿科学   5460篇
妇产科学   2437篇
基础医学   3331篇
口腔科学   1564篇
临床医学   26742篇
内科学   47577篇
皮肤病学   7469篇
神经病学   14891篇
特种医学   6361篇
外科学   41144篇
综合类   233篇
现状与发展   72篇
一般理论   1篇
预防医学   7033篇
眼科学   3379篇
药学   1073篇
中国医学   17篇
肿瘤学   11992篇
  2024年   512篇
  2023年   4795篇
  2022年   1187篇
  2021年   3091篇
  2020年   6036篇
  2019年   2183篇
  2018年   7411篇
  2017年   7353篇
  2016年   8424篇
  2015年   8442篇
  2014年   15537篇
  2013年   15648篇
  2012年   5537篇
  2011年   5548篇
  2010年   10409篇
  2009年   14291篇
  2008年   5878篇
  2007年   4102篇
  2006年   6575篇
  2005年   3849篇
  2004年   3136篇
  2003年   2095篇
  2002年   2182篇
  2001年   3847篇
  2000年   3029篇
  1999年   3239篇
  1998年   3660篇
  1997年   3486篇
  1996年   3401篇
  1995年   3239篇
  1994年   1968篇
  1993年   1575篇
  1992年   1403篇
  1991年   1427篇
  1990年   1082篇
  1989年   1198篇
  1988年   1030篇
  1987年   868篇
  1986年   900篇
  1985年   729篇
  1984年   564篇
  1983年   527篇
  1982年   525篇
  1981年   399篇
  1980年   367篇
  1979年   317篇
  1978年   336篇
  1977年   402篇
  1975年   285篇
  1972年   305篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
971.
972.
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   
973.
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   
974.
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   
975.
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   
976.
977.
978.
979.
980.
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