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   5272篇
  免费   277篇
  国内免费   13篇
耳鼻咽喉   34篇
儿科学   264篇
妇产科学   115篇
基础医学   660篇
口腔科学   142篇
临床医学   389篇
内科学   1114篇
皮肤病学   428篇
神经病学   266篇
特种医学   95篇
外科学   527篇
综合类   100篇
一般理论   2篇
预防医学   296篇
眼科学   313篇
药学   465篇
中国医学   18篇
肿瘤学   334篇
  2023年   54篇
  2022年   128篇
  2021年   273篇
  2020年   129篇
  2019年   194篇
  2018年   212篇
  2017年   141篇
  2016年   177篇
  2015年   159篇
  2014年   225篇
  2013年   270篇
  2012年   368篇
  2011年   377篇
  2010年   232篇
  2009年   199篇
  2008年   249篇
  2007年   262篇
  2006年   256篇
  2005年   233篇
  2004年   210篇
  2003年   196篇
  2002年   204篇
  2001年   85篇
  2000年   97篇
  1999年   70篇
  1998年   31篇
  1997年   25篇
  1996年   30篇
  1995年   14篇
  1994年   19篇
  1993年   23篇
  1992年   38篇
  1991年   30篇
  1990年   49篇
  1989年   45篇
  1988年   36篇
  1987年   29篇
  1986年   26篇
  1985年   24篇
  1984年   16篇
  1983年   14篇
  1982年   11篇
  1981年   8篇
  1980年   11篇
  1979年   12篇
  1978年   10篇
  1977年   13篇
  1974年   6篇
  1972年   6篇
  1971年   7篇
排序方式: 共有5562条查询结果,搜索用时 140 毫秒
21.
Metastatic eyelid tumours are rare and account for less than 2% of all eyelid neoplasms. We report a case of metastatic breast carcinoma to the eyelid in a 60-year-old Chinese lady presenting with a 2-year history of enlarging, painless nodular lower eyelid swelling. The 1 cm diameter lesion was provisionally diagnosed as a sebaceous cyst. However the excision biopsy revealed a mucinous carcinoma expressing oestrogen receptor protein. She had a past history of mastectomy one year previously and histology showed an infiltrating ductal carcinoma (oestrogen receptor status negative) without evidence of axillary lymph node metastasis. She had completed adjuvant radio- and chemotherapy. Further treatment of the current lesion involved a wide excision which did not show any residual malignancy. She had no other evidence of metastasis and was treated with letrozol. We highlight this case to create awareness among clinicians and opthalmologists on the possibility of metastatic disease as a cause of eyelid swelling, especially in patients with a history of cancer. It may also be the first sign of metastatic disease of an internal malignancy. A review of the literature is also presented.  相似文献   
22.
23.
This study examined sociodemographic, behavioral and psychosocial factors associated with BMI, weight perceptions and trying to lose weight among African-American smokers (N=600, M=44.2 years, 70% female). Sixty-eight percent of the sample were overweight or obese (sample BMI M=28.0, SD=6.7). Three separate, simultaneous multivariable regression models were used to determine which factors were associated with BMI, weight perceptions and trying to lose weight. Poorer health, female gender and high-school education or higher were significantly associated with higher BMIs (p<0.05). Being female (OR=5.8, 95% CI=3.6-9.3) and having a higher BMI (OR=0.6, 95% CI=0.5-0.6) was associated with perception of overweight and smoking more cigarettes per day (OR=1.0, 95% CI=1.0-1.1), and perceiving oneself as overweight (OR=14.1, 95% CI=8.2-24.2) was associated with trying to lose weight. Participants somewhat underestimated their BMI in their weight perceptions. Those who perceived themselves as overweight were more likely to be trying to lose weight; therefore, increasing participant awareness of actual BMI status may lead to improved weight-control efforts in African-American smokers. Several expected associations with outcomes were not found, suggesting that BMI and weight constructs are not well-understood in this population.  相似文献   
24.
25.
26.
27.
Cornelia de Lange syndrome (CdLS; OMIM 122470) is a dominantly inherited disorder characterized by multisystem involvement, cognitive delay, limb defects, and characteristic facial features. Recently, mutations in NIPBL have been found in approximately 50% of individuals with CdLS. Numerous chromosomal rearrangements have been reported in individuals with CdLS. These rearrangements may be causative of a CdLS phenotype, result in a phenocopy, or be unrelated to the observed phenotype. We describe two half siblings with a der(3)t(3;12)(p25.3;p13.3) chromosomal rearrangement, clinical features resembling CdLS, and phenotypic overlap with the del(3)(p25) phenotype. Region-specific BAC probes were used to fine-map the breakpoint region by fluorescence in situ hybridization (FISH). FISH analysis places the chromosome 3 breakpoint distal to RP11-115G3 on 3p25.3; the chromosome 12 breakpoint is distal to BAC RP11-88D16 on 12p13.3. A review of published cases of terminal 3p deletions and terminal 12p duplications indicates that the findings in these siblings are consistent with the del(3)(p25) phenotype. Given the phenotypic overlap with CdLS, we have reviewed the reported cases of chromosomal rearrangements involved in CdLS to better elucidate other potential loci that could harbor additional CdLS genes. Additionally, to identify chromosome rearrangements, genome-wide array comparative genomic hybridization (CGH) was performed on eight individuals with typical CdLS and without identifiable deletion or mutation of NIPBL. No pathologic rearrangements were identified.  相似文献   
28.
To determine hepatitis B virus genotype and subtype distribution among HBV infected individuals with different clinical manifestations in western India, serum samples from 19 asymptomatic hepatitis B surface antigen carriers, 30 chronic hepatitis B patients, 8 acute hepatitis B patients, 5 fulminant hepatitis B patients, and with circulating HBV DNA were genotyped and subtyped on the basis of the nucleotide sequence analysis of S region of the HBV genome. Genotype D was the predominant genotype circulating in western India (57/62; 91.93%). All 19 asymptomatic hepatitis B surface antigen carriers, 8 acute hepatitis B patients, 5 fulminant hepatic failure patients and 25/30 chronic hepatitis B patients were circulating genotype D and ayw3/ayw2 subtypes. HBV genotype A was prevalent in 8% (5/62) of the total number of patients and all belonged to chronic hepatitis B category. Subtyping analysis showed that all genotype A isolates were of subtype adw2. As most of the patients from different clinical categories were infected with HBV genotype D, it is concluded that this genotype did not influence the outcome of HBV infection.  相似文献   
29.
A comparative study involving SDS-PAGE of Salmonella typhi and other Bacteria was conducted. Protoplasmic antigens of Salmonella typhi. Salmonella paratyphi A, Salmonella typhimurium, Proteus sp, Klebsiellas sp. Pseudomonas aeruginosa, Shigella flexneri, Staphylococcus aureus were separated and compared on SDS-PAGE followed by checking of their cross reactivity by gel diffusion using antisera raised against whole cell and lysates of Salmonella typhi. Lines of identity between Salmonella typhi, Salmonella paratyphi A and Salmonella typhimurium were observed. No lines of identity were seen among Salmonella typhi, Pseudomonas aeruginosa and Sfaphylococcus aureus.  相似文献   
30.
The duty of confidentiality in the normal doctor-patient relationship is well recognized. However, the duty of confidentiality between the pathologist who performs the autopsy and the requesting authorities and the next-of-kin is not as clearly spelt out. This article discusses the problems faced by the pathologist with regards to hospital and medico-legal autopsies in Malaysia. A proposed ethical guideline is included on how to deal with peculiar issues regarding confidentiality and the pathologist.  相似文献   
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