全文获取类型
收费全文 | 41865篇 |
免费 | 3515篇 |
国内免费 | 1356篇 |
专业分类
耳鼻咽喉 | 506篇 |
儿科学 | 825篇 |
妇产科学 | 726篇 |
基础医学 | 5038篇 |
口腔科学 | 808篇 |
临床医学 | 4460篇 |
内科学 | 7039篇 |
皮肤病学 | 835篇 |
神经病学 | 3013篇 |
特种医学 | 1424篇 |
外国民族医学 | 13篇 |
外科学 | 6006篇 |
综合类 | 4137篇 |
现状与发展 | 4篇 |
一般理论 | 24篇 |
预防医学 | 2903篇 |
眼科学 | 1303篇 |
药学 | 3440篇 |
18篇 | |
中国医学 | 1091篇 |
肿瘤学 | 3123篇 |
出版年
2023年 | 435篇 |
2022年 | 862篇 |
2021年 | 1639篇 |
2020年 | 1182篇 |
2019年 | 1196篇 |
2018年 | 1374篇 |
2017年 | 1181篇 |
2016年 | 1191篇 |
2015年 | 1526篇 |
2014年 | 1944篇 |
2013年 | 2006篇 |
2012年 | 3122篇 |
2011年 | 3075篇 |
2010年 | 1747篇 |
2009年 | 1458篇 |
2008年 | 2225篇 |
2007年 | 2289篇 |
2006年 | 2193篇 |
2005年 | 2228篇 |
2004年 | 1722篇 |
2003年 | 1530篇 |
2002年 | 1341篇 |
2001年 | 906篇 |
2000年 | 907篇 |
1999年 | 915篇 |
1998年 | 515篇 |
1997年 | 429篇 |
1996年 | 338篇 |
1995年 | 346篇 |
1994年 | 284篇 |
1993年 | 221篇 |
1992年 | 385篇 |
1991年 | 365篇 |
1990年 | 356篇 |
1989年 | 323篇 |
1988年 | 285篇 |
1987年 | 264篇 |
1986年 | 262篇 |
1985年 | 206篇 |
1984年 | 187篇 |
1983年 | 135篇 |
1982年 | 95篇 |
1981年 | 111篇 |
1979年 | 126篇 |
1978年 | 114篇 |
1977年 | 103篇 |
1976年 | 102篇 |
1974年 | 121篇 |
1973年 | 120篇 |
1972年 | 92篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
52.
53.
Clinical experience of phototherapy for non-haemolytic hyperbilirubinaemia in 3999 infants in Kandang Kerbau Hospital, Singapore, is documented. Phototherapy was most effective in extremely preterm infants with very low birth weight (gestation less than or equal to 32 weeks, birth weight less than or equal to 1500 g) and least effective in full term infants with very low birth weight (gestation greater than or equal to 37 weeks, birth weight less than or equal to 1500 g) and large preterm infants (gestation less than 37 weeks, birth weight greater than 2270 g). Overall, phototherapy was effective in almost all the infants, with a failure rate of only 2.00/1000 infants. No characteristic features common to all the failures could be detected. The bilirubin rebound was usually mild; repeat phototherapy was required in only 30 infants (7.50/1000), with the response to the second exposure comparable to that to the first. No infant required a third exposure. All the infants tolerated phototherapy well, none developing any illness that could be attributed to the treatment. This clinical experience shows that phototherapy for the treatment of nonhaemolytic hyperbilirubinaemia is effective and safe. 相似文献
54.
膳食黑米皮抑制高脂诱导的家兔动脉粥样硬化形成及其机制的初步探讨 总被引:1,自引:0,他引:1
目的 探讨膳食黑米皮对高脂诱导的家兔动脉粥样硬化形成的影响及其作用机制。方法 24只雄性新西兰大耳白家兔,按体重随机分为3组,分别饲以正常基础饲料、高脂饲料(含96%基础饲料、0.5%胆固醇、3.5%猪油)、黑米皮饲料(含 91%基础饲料、0.5%胆固醇、3.5%猪油、5%黑米皮),实验期为 60d。用图像分析法测定各组家兔主动脉脂质斑块面积,并分析家兔氧化与抗氧化状态。结果 黑米皮实验家兔的主动脉壁斑块面积较高脂组低66%(P<0.001);黑米皮组实验家兔的主动脉壁8-ohdG含量和血清及主动脉壁中MDA水平也低于高脂组(P<0.05 );而红细胞及主动脉壁中SOD水平和血清α-生育酚含量在两个处理组之间差异无显著性。结论 膳食黑米皮可以抑制高脂诱导的家兔动脉粥样硬化形成,其机制可能与之降低机体氧化应激水平及过氧化脂质生成有关。 相似文献
55.
Sherry X Yang Richard M Simon Antoinette R Tan Diana Nguyen Sandra M Swain 《Clinical cancer research》2005,11(17):6226-6232
PURPOSE: To delineate gene expression patterns and profile changes in metastatic tumor biopsies at baseline and 1 month after treatment with the epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor erlotinib in patients with metastatic breast cancer. EXPERIMENTAL DESIGN: Patients were treated with 150 mg of oral erlotinib daily. Gene expression profiles were measured with Affymetrix U133A GeneChip and immunohistochemistry was used to validate microarray findings. RESULTS: Estrogen receptor (ER) status by immunohistochemistry is nearly coincided with the two major expression clusters determined by expression of genes using unsupervised hierarchical clustering analysis. One of 10 patients had an EGFR-positive tumor detected by both microarray and immunohistochemistry. In this tumor, tissue inhibitor of metalloproteinases-3 and collagen type 1 alpha 2, which are the EGF-down-regulated growth repressors, were significantly increased by erlotinib. Gene changes in EGFR-negative tumors are those of G-protein-linked and cell surface receptor-linked signaling. Gene ontology comparison analysis pretreatment and posttreatment in EGFR-negative tumors revealed biological process categories that have more genes differentially expressed than expected by chance. Among 495 gene ontology categories, the significant differed gene ontology groups include G-protein-coupled receptor protein signaling (34 genes, P = 0.002) and cell surface receptor-linked signal transduction (74 genes, P = 0.007). CONCLUSIONS: ER status reflects the major difference in gene expression pattern in metastatic breast cancer. Erlotinib had effects on genes of EGFR signaling pathway in the EGFR-positive tumor and on gene ontology biological process categories or genes that have function in signal transduction in EGFR-negative tumors. 相似文献
56.
保留肾单位手术治疗早期小肾癌21例临床分析 总被引:1,自引:0,他引:1
Yao-Jun Xiao Shao-Bin Zheng Wan-Long Tan Tong Chen Huan Qi Zhi-Qiang Shao Yao-Dong Jiang Peng Wu Hui-Jian Zhang 《第一军医大学学报》2005,25(3):357-359
OBJECTIVE: To evaluate the clinical effects of nephron-sparing surgery in patients with early-stage small renal cell carcinoma. METHODS: Nephron-sparing surgery was performed in 21 patients with renal cell carcinoma including 1 with solitary kidney, 3 with unilateral tumor and contralateral renal compromise, and 17 with unilateral tumor and normal contralateral kidney. The diameter of the tumors ranged from 1.5 to 6.0 cm, with a mean of 2.8 cm. The tumor diameter in 17 patients with normal contralateral kidney was less than 4 cm (mean 2.5 cm) and the average diameter in 4 patients with contralateral renal compromise was 4.2 cm. Sixteen cases were in stage T(1), 4 in stage T(2), and 1 in stage T(3). Of the 21 patients, 4 underwent tumor enucleation, 10 polar nephrectomy and 7 wedge resection. RESULTS: All patients were followed up for an average of 40.8 months (7 to 66 months). One patient suffered a right lung and mediastinum metastasis 3 years after the surgery later and 1 with chronic glomerulonephritis required dialysis 27 months after the operation. No surgical complication or local recurrence were found in other patients. CONCLUSION: As a safe and effective therapy for early-stage small renal cell carcinoma, nephron-sparing surgery can be considered as the gold-standard therapy for patients with lesions less than 4 cm in T(1) and T(2) stages of localized unilateral tumor with normal contralateral kidney. 相似文献
57.
J. Bryan Page 《Journal of urban health》2005,82(3):iii35-iii43
Contemporary discourse contains numerous examples of use of the concept of culture by social and behavioral scientists. Simple reification, where the speaker makes culture into a thing capable of action exemplifies one usage in public discourse. Some quantitative social scientists attempt to characterize people’s cultural identities by means of a single categorical variable, which often “lumps” people into categories such as “Hispanic” or “Black” that in fact have numerous culturally bounded subcategories. Approaches that emphasize cultural process are preferable to those who attempt to categorize; more complex measures of acculturation help investigators to make convincing analyses of circumstances in which health disparities occur. Examples in which investigators make appropriate use of cultural characterizations demonstrate their utility in investigating health disparities in Haitian American women, injecting and noninjecting drug users, Hispanic youth, and adult Hispanics at risk of HIV infection. Focus on culture in the study of health disparities can identify entanglements between structural factors such as poverty and lack of education and cultural factors such as beliefs about health. Qualitative methods coupled with quantitative methods have great potential to improve investigators’ grasp of cultural nuance while capturing the distribution of qualitatively derived behaviors. 相似文献
58.
Angela Bryan Reuben N Robbins Monica S Ruiz Dennis O'Neill 《Health education & behavior》2006,33(2):154-177
Prisons and prison inmates present important targets for HIV/AIDS prevention interventions. Inmates often have histories of high-risk behavior that place them in danger of contracting HIV/AIDS, and rates of HIV/AIDS tend to be much higher in this population. The goal of this study was to assess the effectiveness of a prison-based HIV/AIDS intervention to change attitudes toward HIV prevention, norms supporting HIV prevention, perceived behavioral control (i.e., self-efficacy) for HIV prevention behaviors, and intentions to engage in HIV prevention behaviors postrelease. The intervention also had the goal of encouraging inmates to become HIV/AIDS peer educators. The intervention appeared most successful at influencing beliefs and behaviors related to peer education and somewhat successful at influencing beliefs and intentions related to condom use. Analyses also showed some significant differences in effectiveness by race/ethnicity. Results are discussed from the perspectives of both research and practice with regard to prison-based HIV prevention efforts. 相似文献
59.
S.L. Ezekiel Tan 《Injury》2009,40(7):683-691
The goal of fracture fixation is to achieve bone healing and restore the function of the injured limb in the shortest possible time without compromising safety. Newer technologies such as the locking compression plate (LCP) and its derivatives are valuable additions to the orthopaedic traumatologist's armamentarium. As with any emerging technology, the indications will be extended until a threshold is reached and the limitations of the technology are seen. It is vital that surgeons involved in fracture care are aware of when locked plating is superior to other methods and also when they should use another treatment modality.This paper reviews the use of locked plating as a fixation method. Five topics covered in this review are: a historical perspective on locked plating, general indications, specific modes and techniques, patterns of failure, and an anatomical overview of current indications for locked plating. 相似文献
60.