全文获取类型
收费全文 | 1711篇 |
免费 | 111篇 |
国内免费 | 3篇 |
专业分类
耳鼻咽喉 | 23篇 |
儿科学 | 47篇 |
妇产科学 | 47篇 |
基础医学 | 201篇 |
口腔科学 | 15篇 |
临床医学 | 112篇 |
内科学 | 299篇 |
皮肤病学 | 50篇 |
神经病学 | 99篇 |
特种医学 | 126篇 |
外科学 | 297篇 |
综合类 | 119篇 |
一般理论 | 3篇 |
预防医学 | 130篇 |
眼科学 | 29篇 |
药学 | 130篇 |
中国医学 | 5篇 |
肿瘤学 | 93篇 |
出版年
2023年 | 14篇 |
2022年 | 37篇 |
2021年 | 66篇 |
2020年 | 38篇 |
2019年 | 43篇 |
2018年 | 57篇 |
2017年 | 36篇 |
2016年 | 39篇 |
2015年 | 53篇 |
2014年 | 50篇 |
2013年 | 82篇 |
2012年 | 143篇 |
2011年 | 124篇 |
2010年 | 73篇 |
2009年 | 69篇 |
2008年 | 100篇 |
2007年 | 97篇 |
2006年 | 61篇 |
2005年 | 73篇 |
2004年 | 61篇 |
2003年 | 67篇 |
2002年 | 56篇 |
2001年 | 44篇 |
2000年 | 27篇 |
1999年 | 38篇 |
1998年 | 21篇 |
1997年 | 16篇 |
1996年 | 14篇 |
1995年 | 21篇 |
1994年 | 13篇 |
1993年 | 25篇 |
1992年 | 11篇 |
1991年 | 8篇 |
1990年 | 7篇 |
1989年 | 14篇 |
1988年 | 14篇 |
1987年 | 14篇 |
1986年 | 11篇 |
1985年 | 11篇 |
1984年 | 5篇 |
1983年 | 8篇 |
1981年 | 6篇 |
1980年 | 4篇 |
1979年 | 7篇 |
1978年 | 4篇 |
1977年 | 6篇 |
1976年 | 7篇 |
1975年 | 7篇 |
1974年 | 4篇 |
1972年 | 7篇 |
排序方式: 共有1825条查询结果,搜索用时 31 毫秒
21.
Over the next 25 years, as populations age and tobacco consumption increases, most developing regions will likely see noncommunicable diseases become the leading causes of disability and premature mortality. The already existing problems of malnutrition and infectious diseases will remain. In this context, the World Bank is examining its role and contribution to global health. From a small start approximately 25 years ago, the Bank has greatly expanded its role in international health, population, and nutrition to become the largest single external financier of health activities in low- and middle-income countries. Many other Bank-supported activities affect health, including poverty reduction, housing, water and sanitation, and the education of girls. The Bank is also increasingly active in health policy debates, publishing numerous studies annually. Most of these studies focus upon specific countries, but some address key issues of concern to many developing countries. This article explains why the Bank continues to expand its resources devoted to health and the rationale for the changing emphasis of its activities in the field. 相似文献
22.
Genistein, tyrphostin and piceatannol, which are specific inhibitors of protein tyrosine kinase, were screened for their effects on the motility of intact and demembranated hamster spermatozoa. Of the three inhibitors only piceatannol inhibited the motility of intact spermatozoa. None of the inhibitors had any inhibitory effect on the reactivation of motility of demembranated hamster spermatozoa. Taken together these results indicated that a protein tyrosine kinase associated with the membrane of hamster spermatozoa was probably involved in sustenance of hamster sperm motility. Therefore in the present study a membrane-associated protein tyrosine kinase was purified from a detergent-soluble extract of plasma membranes of mature hamster spermatozoa. The purification involved cation exchange chromatography on fast protein liquid chromatography (FPLC) followed by affinity chromatography either on an antiphosphotyrosine antibody agarose or poly glu-tyr agarose column. The pure protein tyrosine kinase had an apparent molecular mass of 45 kDa. The enzyme was not inhibited by genistein or herbimycin but was inhibited by piceatannol. This is the first report on the purification of a sperm plasma membrane-associated protein tyrosine kinase, an enzyme which has also been implicated in hamster sperm motility. 相似文献
23.
B J Jha S Dey M D Tamang M E Joshy P G Shivananda K N Brahmadatan 《Kathmandu University Medical Journal》2006,4(3):290-294
Objectives: (1) To identify and characterize the Candida species isolates from lower respiratory tract infection. (2) to determine the rate of isolation of Candida species from sputum samples. Methods: This study was carried out in the Department of Microbiology, Manipal Teaching Hospital, Pokhara, Nepal from June 2002 to January 2003. A total of 462 sputum samples were collected from patients suspected lower respiratory tract infection. The samples were processed as Gram staining to find out the suitability of the specimen, cultured on Sabouraud's Dextrose Agar (SDA) and also on blood agar and chocolate agar to identify the potential lower respiratory tract pathogens. For the identification of Candida, sputum samples were processed for Gram stain, culture, germ tube test, production of chlamydospore, sugar fermentation and assimilation test. For the identification of bacteria, Gram stain, culture, and biochemical tests were performed by standardized procedure. Result: Out of 462 samples, 246 (53.24%) samples grew potential pathogens of lower respiratory tract. Among them Haemophilus influenzae 61(24.79%) and Streptococcus pneumoniae 57 (23.17%) were the predominant bacterial pathogens. Candida species were isolated from 30 samples (12.2%). The majority of Candida species amongst the Candida isolates were Candida albicans 21(70%) followed by Candida tropicalis 4(13.33%). Candida krusei 3(10%), Candida parapsilosis 1(3.33%) and Candida stellatoidea 1(3.33%). The highest rate of isolation of Candida was between the age of 71 and 80. Conclusion: Candida isolation from sputum samples is important as found in the present study in which Candida species were the third most common pathogen isolated from patients with lower respiratory tract infection. Key words: Candida albicans, Pulmonary candidiasis, Nepal. 相似文献
24.
This study was undertaken to investigate the antidiabetic and antioxidant activities of crude extracts and pure compounds from the aerial parts of Calamintha officinalis Moench. (Lamiaceae). The aqueous extract showed the promising antidiabetic and antioxidant activities. Based on these findings, the aqueous extract was fractionated on a silica gel column chromatography in a bioassay-guided fractionation affording two known hydroxycinnamic acids showing potent activity (1) rosamarinic acid and (2) caffeic acid. Both rosamarinic acid and caffeic acid exhibited significant activity, even more than the positive control, glibenclamide. The results indicated that Calamintha officinalis aqueous extract and the isolated compounds are potential natural agents for the control of diabetes. 相似文献
25.
26.
Amit Kumar Pandey Yanzhou Zhang Siting Zhang Ying Li Greg Tucker-Kellogg Henry Yang Sudhakar Jha 《Oncotarget》2015,6(38):41290-41306
MicroRNAs (miRNAs) are 22- to 24-nucleotide, small, non-coding RNAs that bind to the 3′UTR of target genes to control gene expression. Consequently, their dysregulation contributes to many diseases, including diabetes and cancer. miR-22 is up-regulated in numerous metastatic cancers and recent studies have suggested a role for miR-22 in promoting stemness and metastasis. TIP60 is a lysine acetyl-transferase reported to be down-regulated in cancer but the molecular mechanism of this reduction is still unclear. In this study, we identify TIP60 as a target of miR-22. We show a negative correlation in the expression of TIP60 and miR-22 in breast cancer patients, and show that low levels of TIP60 and high levels of miR-22 are associated with poor overall survival. Furthermore, pathway analysis using high miR-22/low TIP60 and low miR-22/high TIP60 breast cancer patient datasets suggests association of TIP60/miR-22 with epithelial-mesenchymal transition (EMT), a key alteration in progression of cancer cells. We show that blocking endogenous miR-22 can restore TIP60 levels, which in turn decreases the migration and invasion capacity of metastatic breast cancer cell line. These results provide mechanistic insight into TIP60 regulation and evidence for the utility of the combination of TIP60 and miR-22 as prognostic indicator of breast cancer progression. 相似文献
27.
28.
Gunjan Pruthi Veena Jain Suresh Rajendiran Ritu Jha 《Indian journal of ophthalmology》2014,62(5):629-632
Orbital exenteration is executed by the ophthalmic surgeon to treat various neoplasms or non-malignant diseases. But it leads to several functional, esthetic and psychological problems for the patients. Orbital prosthesis is a good alternative for cosmetic and psychological rehabilitation, if reconstructive surgery is not possible or not desired by the patient. In the following article, different materials and retentive aids for fabrication of an orbital prosthesis given in the literature along with few novel methods have been discussed for four patients who underwent orbital exenteration. Factors that an ophthalmic surgeon should consider during surgery, which may later on help the prosthodontist to obtain good cosmetic results, are also discussed briefly. Remarkable results can be obtained if both work as a team for one common goal i.e. improvement of quality of life of the patient after orbital exenteration. 相似文献
29.
30.
ABSTRACT: BACKGROUND: Introducing a new method into family planning programs requires careful attention to ensure it meets an actual need and has a positive effect on program goals. The Standard Days Method(R) is a fertility awareness-based method of family planning that is being introduced into family planning programs in countries around the world. It is different from other methods offered by programs, and may bring new couples into family planning, and increase contraceptive prevalence. The study assesses the effect on contraceptive use and prevalence of Introducing Standard Days Method into existing family planning services in whole regions of India, Peru, and Rwanda. METHODS: In collaboration with the Ministry of Health, health providers were given a contraceptive update on all methods, then trained in counseling on Standard Days Method. Efforts were made to promote demand in the context of informed choice. Routine monthly service statistics in control and intervention areas were used to assess the effect of Standard Days Method introduction at the clinic level; baseline and endline household-based surveys were undertaken to obtain results at the community level (n > 3400 women at endline). RESULTS: Demand for the method is evident in countries with different levels of contraceptive prevalence. The method attracts couples new to family planning, and introducing it into services may increase overall contraceptive prevalence. CONCLUSIONS: Introducing Standard Days Method into existing family planning has the potential of benefiting men and women in diverse settings and populations. This study illustrates the critical role of evidence in scaling up a health innovation. 相似文献