全文获取类型
收费全文 | 90481篇 |
免费 | 6888篇 |
国内免费 | 4323篇 |
专业分类
耳鼻咽喉 | 1282篇 |
儿科学 | 1008篇 |
妇产科学 | 741篇 |
基础医学 | 10984篇 |
口腔科学 | 1581篇 |
临床医学 | 8921篇 |
内科学 | 12667篇 |
皮肤病学 | 1643篇 |
神经病学 | 4540篇 |
特种医学 | 4517篇 |
外国民族医学 | 8篇 |
外科学 | 11726篇 |
综合类 | 13779篇 |
现状与发展 | 15篇 |
一般理论 | 9篇 |
预防医学 | 6358篇 |
眼科学 | 1774篇 |
药学 | 8968篇 |
57篇 | |
中国医学 | 4432篇 |
肿瘤学 | 6682篇 |
出版年
2024年 | 170篇 |
2023年 | 812篇 |
2022年 | 2245篇 |
2021年 | 3268篇 |
2020年 | 2376篇 |
2019年 | 2212篇 |
2018年 | 2383篇 |
2017年 | 2371篇 |
2016年 | 2552篇 |
2015年 | 3941篇 |
2014年 | 4940篇 |
2013年 | 5528篇 |
2012年 | 8119篇 |
2011年 | 8158篇 |
2010年 | 6033篇 |
2009年 | 5217篇 |
2008年 | 6071篇 |
2007年 | 5804篇 |
2006年 | 5324篇 |
2005年 | 4540篇 |
2004年 | 3628篇 |
2003年 | 3470篇 |
2002年 | 3049篇 |
2001年 | 2297篇 |
2000年 | 1609篇 |
1999年 | 1093篇 |
1998年 | 550篇 |
1997年 | 517篇 |
1996年 | 382篇 |
1995年 | 313篇 |
1994年 | 243篇 |
1993年 | 162篇 |
1992年 | 262篇 |
1991年 | 274篇 |
1990年 | 190篇 |
1989年 | 192篇 |
1988年 | 165篇 |
1987年 | 169篇 |
1986年 | 142篇 |
1985年 | 133篇 |
1984年 | 79篇 |
1983年 | 82篇 |
1982年 | 66篇 |
1981年 | 50篇 |
1980年 | 45篇 |
1979年 | 69篇 |
1978年 | 69篇 |
1977年 | 50篇 |
1974年 | 38篇 |
1973年 | 42篇 |
排序方式: 共有10000条查询结果,搜索用时 54 毫秒
1.
Tian-Yuan Xiong Fang-Yang Huang Qi Liu Yong Peng Yuan-Ning Xu Jia-Fu Wei 《Annals of medicine》2020,52(7):361-366
Abstract
Background
Comorbidities are commonly seen in patients with coronavirus disease 2019 (COVID-19), but the clinical implication is not yet well-delineated. We aim to characterize the prevalence and clinical implications of comorbidities in patients with COVID-19. 相似文献2.
PURPOSE: Concern over stigma as a consequence of genetic testing has grown in response to the recent increase in genetic research and testing resulting from the Human Genome Project. However, whether a genetic or hereditary basis necessarily confers a stigma to a condition remains unexamined. METHODS: We performed a qualitative interview study with 86 individuals with one of four conditions: deafness or hearing loss, breast cancer, sickle cell disease, and cystic fibrosis. The first two groups were divided approximately between people who ascribed their conditions to a genetic or hereditary cause and those who did not. RESULTS: Respondents interpreted genetic or hereditary causes and nongenetic causes in a variety of ways. Subjects with breast cancer reported the most consistently negative interpretation of genetic cause. This response concerned future ill health, not an enduring sense of stigma. Deaf and hard of hearing subjects provided the most consistently positive comments about a genetic or hereditary basis to their condition, casting familial hearing loss as a vital component of group and individual identity. Respondents with sickle cell disease and cystic fibrosis offered similar and positive interpretations of the genetic cause of their condition insofar as it meant their conditions were not contagious. CONCLUSIONS: Although some subjects report feeling stigmatized as a result of their condition, this stigmatization is not uniformly associated with the condition's cause, genetic or otherwise. Instead, stigma emerges from a variety of sources in the context of the lived experience of a particular condition. 相似文献
3.
The response of single detergent treated bovine retinal pigment epithelial cells in culture to ATP was measured with an image analyser. The most pronounced contraction was produced by 1.0 mM ATP with most change taking place in the first 10 min. At 1 h the area had decreased by about 33%, perimeter 22% and maximum length 25%. By way of comparison rabbit skin fibroblasts had a decreased area of approximately 40%, perimeter 25% and maximum length 22%. Bovine aortic smooth muscle cells on the other hand decreased in area by 55%, perimeter 40% and maximum length 36%. It is hoped that this assay may be used to evaluate drugs which could counteract contractile events in proliferative vitreoretinopathy. 相似文献
4.
5.
Je-Yong Choi Hyung-Jong Kim Yong-Chan Lee Byoung-Ouck Cho Ha-Soo Seong Michael Cho Seong-Gon Kim 《Oral surgery, oral medicine, oral pathology, oral radiology, and endodontics》2007,103(3):321-328
OBJECTIVE: Pamidronate has been studied as a therapeutic drug for various osteopenic diseases. However, avascular osteonecrosis in the jawbone has been recently reported in patients receiving pamidronate. The objective of this study was to examine the effect of pamidronate on bone regeneration in a controlled animal model. MATERIALS AND METHODS: To determine the effect of parmidronate on bone healing in a local bony defect area, a rabbit calvarial bony defect model was used and poly L-lactide-co-glycolide (PLGA) used as a drug carrier material. Four defect groups were made in each rabbit calvaria and the defects were treated as follows: untreated bony defect (group 1), PLGA only (group 2), 2 mg of pamidronate with PLGA (group 3), and 3 mg of pamidronate with PLGA (group 4). Bone healing was evaluated by radiography and histology at 1, 2, 4, 6, and 8 weeks after surgery. RESULTS: In radiographic analysis, radiopacity was lower in pamidronate groups than non-operated rabbit calvarial bone at all observation points (P < .05). In histological analysis, the initial bone formation at 1 week was not different among groups, but it was much lower in the pamidronate groups than in the control or PLGA group after 2 weeks. Newly formed bone at 1 week underwent avascular necrosis after 2 weeks in both pamidronate groups. Avascular necrosis was not observed until 8 weeks in both topically applied pamidronate groups. CONCLUSION: Collectively, pamidronate inhibits bone healing in rabbit calvarial bony defect and it may explain the avascular necrosis of the jaws in patients receiving pamidronate. 相似文献
6.
7.
Hyo-Chang Kim Seok-Gu Kang Pil-Woo Huh Do Sung Yoo Kyoung Suok Cho Dal Soo Kim 《Journal of clinical neuroscience》2007,14(11):1135-1139
Pituitary abscess is a rare and potentially lethal condition. Pituitary abscess in a pregnant woman has not been previously described. A 38-year-old pregnant woman (34 weeks gestation) with a pituitary mass complained of a progressive headache and sudden visual impairment. She was afebrile and had no inflammatory symptoms on admission. On MRI, the preoperative diagnosis was pituitary adenoma with sphenoid sinusitis. She underwent an uncomplicated transsphenoidal procedure for removal of the pituitary mass. The next day, labor commenced and a healthy preterm baby was delivered. Pathologic examination of the intrasellar mass showed polymorphonuclear cells, debris and no tumor cells. The sellar contents were cultured and Streptococcus viridans was grown. To our knowledge this is the first case of pituitary abscess reported during pregnancy. Although the patient was pregnant, the transsphenoidal approach was safe for the mother and the fetus. Surgical drainage and antibiotic therapy are required for the definitive treatment of this condition. 相似文献
8.
9.
Transforminggrowthfactor-β1(TGF-β1)is amultifunctionalpolypeptidethatregulatesanum-berofcellularprocesses,includingcellprolifera-tion,differentiation,apoptosis,migration,matrix synthesis,andtheimmuneresponse[1,2].Inchron-icrenaldiseases,TGF-β1isakeymediatorofex-tracellularmatrix(ECM)accumulation[3].Oneof thetargetrenalcellsforTGF-β1isglomerular mesangialcellsthatarecapableofproducingcom-ponentsofECM,suchascollagens,lamininand fibronectin[4,5].Recentstudiesindicatedthatinhi-bitionofT… 相似文献
10.
Jin Woo Kim M.D. Ho Shik Kim M.D. In Kyung Kim M.D. Mee Ran Kim M.D. Eun Young Cho B.S. Heung Kee Kim M.D. Joon Mo Lee M.D. Sung Eun Namkoong M.D. 《Gynecologic oncology》1998,69(3):230-236
Transforming growth factor-β1 (TGF-β1) is known to be a potent growth inhibitor for many cell types, including most epithelial cells. In skin keratinocytes, TGF-β1 has been shown to inhibit growth and to rapidly reduce c-mycexpression. However, the molecular mechanism of TGF-β1 action on cell growth of cervical carcinoma has not yet been elucidated. We thus assessed the effect of TGF-β1 on the growth of cervical carcinoma cell lines. Two cervical squamous carcinoma cell lines, CUMC-3 and CUMC-6, were incubated with varying concentrations of TGF-β1, and growth inhibition was evaluated with tetrazolium-based colorimetric assay. After culture in TGF-β1 for 24 h, inhibition of growth was detected in a dose-dependent manner at concentrations of 0.1–10 ng/ml in both cell lines. This effect of TGF-β1 on cultured carcinoma cells was associated with apoptotic process including oligonucleosomal ladder DNA and apoptotic body formations. Northern blot analysis revealed c-mycmRNA expression was suppressed by 10 ng/ml of TGF-β1 following 3 h of treatment in both cell lines. Western blot analysis showed that the level of p27Kip1protein was increased after TGF-β1 treatment in both cell lines. These results suggest that the mechanisms by which TGF-β1 inhibits the growth of cervical carcinoma are complex and may include effects on down-regulation of c-mycgene, and overexpression of p27Kip1protein. 相似文献