全文获取类型
收费全文 | 840篇 |
免费 | 57篇 |
国内免费 | 5篇 |
专业分类
耳鼻咽喉 | 9篇 |
儿科学 | 13篇 |
妇产科学 | 31篇 |
基础医学 | 102篇 |
口腔科学 | 8篇 |
临床医学 | 84篇 |
内科学 | 199篇 |
皮肤病学 | 8篇 |
神经病学 | 35篇 |
特种医学 | 19篇 |
外科学 | 141篇 |
综合类 | 32篇 |
预防医学 | 74篇 |
眼科学 | 12篇 |
药学 | 79篇 |
中国医学 | 6篇 |
肿瘤学 | 50篇 |
出版年
2023年 | 11篇 |
2022年 | 15篇 |
2021年 | 45篇 |
2020年 | 25篇 |
2019年 | 33篇 |
2018年 | 41篇 |
2017年 | 20篇 |
2016年 | 22篇 |
2015年 | 29篇 |
2014年 | 40篇 |
2013年 | 37篇 |
2012年 | 64篇 |
2011年 | 60篇 |
2010年 | 45篇 |
2009年 | 30篇 |
2008年 | 41篇 |
2007年 | 47篇 |
2006年 | 27篇 |
2005年 | 38篇 |
2004年 | 37篇 |
2003年 | 36篇 |
2002年 | 26篇 |
2001年 | 8篇 |
2000年 | 15篇 |
1999年 | 13篇 |
1998年 | 7篇 |
1997年 | 6篇 |
1996年 | 4篇 |
1995年 | 8篇 |
1994年 | 4篇 |
1993年 | 2篇 |
1992年 | 8篇 |
1991年 | 6篇 |
1989年 | 6篇 |
1988年 | 9篇 |
1987年 | 7篇 |
1986年 | 4篇 |
1984年 | 2篇 |
1983年 | 2篇 |
1982年 | 3篇 |
1981年 | 2篇 |
1978年 | 1篇 |
1977年 | 2篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1957年 | 1篇 |
1956年 | 1篇 |
1954年 | 2篇 |
1933年 | 2篇 |
1932年 | 2篇 |
排序方式: 共有902条查询结果,搜索用时 46 毫秒
101.
102.
Using the hair baiting technique, 6 genera and 14 species were collected on Sabouraud's dextrose agar from 37 dust samples from air-conditioners. The most common fungi were Chrysosporium tropicum, C. indicum, C. keratinophilum, Aspergillus flavus followed by Acremonium strictum and Scopulariopsis brevicaulis. Using the dilution-plate method, 26 genera and 52 species were collected from 37 dust samples on glucose-(23 genera and 45 species) and cellulose-(18 genera and 34 species) Czapek's agar at 28 degrees C. The most prevalent species were Aspergillus niger, A. flavus, Penicillium chrysogenum, Stachybotrys chartarum, Ulocladium atrum, Mucor racemosus and Fusarium solani and A. niger, A. flavus, Trichoderma viride, P. chrysogenum, Ulocladium atrum, Chaetomium globosum, C. spirale, Stachybotrys chartarum and Mucor racemosus on the two media, respectively. 相似文献
103.
Raza A Lisak L Billmeier J Pervaiz H Mumtaz M Gohar S Wahid K Galili N 《Leukemia & lymphoma》2006,47(3):433-440
This phase II trial investigated the safety and preliminary efficacy of a topotecan/thalidomide combination therapy in patients with myelodysplastic syndrome who had refractory anemia with excess blasts (RAEB), RAEB with transformation, or chronic myelomonocytic anemia. Patients received three 21-day cycles of topotecan 1.25 mg/m2 on days 1-5, which was repeated for two additional cycles in patients whose bone marrow blast percentages did not decrease. Oral thalidomide was then started at 100 mg/day (with the dose escalated up to 300 mg/day if well tolerated) for up to 1 year. Patients were monitored throughout the trial for hematologic and clinical adverse events, and efficacy was assessed using International Working Group (IWG) criteria. Forty-five patients, mostly elderly (median age 68 years; range 52-79 years), were enrolled. Therapy was generally well tolerated compared to high-dose chemotherapy. Three patients died from disease progression/infections during topotecan therapy, and four patients discontinued topotecan because of high-grade neutropenia (two patients), syncope (one patient), or hip surgery (one patient). Of 24 patients who received thalidomide, three discontinued because of treatment-related toxicity. Thirty-eight patients were evaluable for response: nine (24%) had hematologic improvement and 13 (34%) had stable disease. Responses occurred in patients with all disease subtypes. Six patients achieved transfusion independence, and one patient had a trilineage response. Approximately one-third of the patients had decreases in bone marrow blasts of ≥50%. Therefore, a topotecan and thalidomide combination therapy is promising, although further studies are needed to determine the optimum doses and schedule. 相似文献
104.
Summary While testing the antibacterial action of quinine dihydrochloride on staphylococci, a zone of promotion of growth below and above which bacteriostasis occurred was observed. 相似文献
105.
PURPOSE OF REVIEW: Congestive heart failure is a leading cause of morbidity and mortality, especially in older persons. In advanced stages of the disease, congestive heart failure can be associated with serious complications such as cardiac cachexia (defined here as weight loss of more than 6% in 6 months). This review will discuss recent insights into the pathophysiology, anthropometric predictors and potential management of cardiac cachexia. RECENT FINDINGS: Cardiac cachexia and the associated progressive weight loss are sometimes overlooked by care providers. A delay in diagnosis often results in further loss of vital tissues, progressive weakness, fall-related injuries and potentially long-term care institutionalization and/or death. Emerging data suggest that congestive heart failure is a dynamic disorder of many organ systems, including the myocardial, neurohormonal, immune, vascular, gastrointestinal, renal and musculoskeletal systems. It is becoming more widely appreciated that it is the deterioration of this interactive multisystem complex that results in the systemic inflammation and progressive wasting and atrophy of muscle and other organ tissues, which is the hallmark of cardiac cachexia. SUMMARY: Cardiac cachexia in congestive heart failure patients may be associated with a low level of physical activity. A high systemic inflammatory state is another marker of cardiac cachexia. Prudent anti-inflammatory nutrition, dietary supplements and exercise can serve to ameliorate and/or potentially prevent progressive wasting. A better understanding of factors contributing to the development of cardiac cachexia will enable us to design preventive strategies and provide improved care for individuals with this debilitating condition. 相似文献
106.
Nishtar S Bile KM Ahmed A Faruqui AM Mirza Z Shera S Ghaffar A Minhas FA Khan A Jaffery NA Rajput M Mirza YA Aslam M Rahim E 《Preventing chronic disease》2006,3(1):A14
Most developing countries do not comprehensively address chronic diseases as part of their health agendas because of lack of resources, limited capacity within the health system, and the threat that the institution of national-level programs will weaken local health systems and compete with other health issues. An integrated partnership-based approach, however, could obviate some of these obstacles. In Pakistan, a tripartite public-private partnership was developed among the Ministry of Health, the nongovernmental organization (NGO) Heartfile, and World Health Organization. This was the first time an NGO participated in a national health program; NGOs typically assume a contractual role. The partnership developed a national integrated plan for health promotion and the prevention and control of noncommunicable diseases (NCDs), which as of January 2006 is in the first stage of implementation. This plan, called the National Action Plan on NCD Prevention, Control, and Health Promotion (NAP-NCD), was released on May 12, 2004, and attempts to obviate the challenges associated with addressing chronic diseases in countries with limited resources. By developing an integrated approach to chronic diseases at several levels, capitalizing on the strengths of partnerships, building on existing efforts, and focusing primary health care on chronic disease prevention, the NAP-NCD aims to mitigate the effects of national-level programs on local resources. The impact of the NAP-NCD on population outcomes can only be assessed over time. However, this article details the plan's process, its perceived merits, and its limitations in addition to discussing challenges with its implementation, highlighting the value of such partnerships in facilitating the missions and mandates of participating agencies, and suggesting options for generalizability. 相似文献
107.
Multiple emulsions are complex polydispersed systems where both oil in water and water in oil emulsion exists simultaneously which are stabilized by lipophillic and hydrophilic surfactants respectively. The ratio of these surfactants is important in achieving stable multiple emulsions. Among water-in-oil-in-water (w/o/w) and oil-in-water-in-oil (o/w/o) type multiple emulsions, the former has wider areas of application and hence are studied in great detail. Formulation, preparation techniques and in vitro characterization methods for multiple emulsions are reviewed. Various factors affecting the stability of multiple emulsions and the stabilization approaches with specific reference to w/o/w type multiple emulsions are discussed in detail. Favorable drug release mechanisms and/or rate along with in vivo fate of multiple emulsions make them a versatile carrier. It finds wide range of applications in controlled or sustained drug delivery, targeted delivery, taste masking, bioavailability enhancement, enzyme immobilization, etc. Multiple emulsions have also been employed as intermediate step in the microencapsulation process and are the systems of increasing interest for the oral delivery of hydrophilic drugs, which are unstable in gastrointestinal tract like proteins and peptides. With the advancement in techniques for preparation, stabilization and rheological characterization of multiple emulsions, it will be able to provide a novel carrier system for drugs, cosmetics and pharmaceutical agents. In this review, emphasis is laid down on formulation, stabilization techniques and potential applications of multiple emulsion system. 相似文献
108.
Cooperation between FGF8b overexpression and PTEN deficiency in prostate tumorigenesis 总被引:2,自引:0,他引:2
Two commonly occurring genetic aberrations of human prostate cancer [i.e., overexpression of a mitogenic polypeptide (fibroblast growth factor 8, isoform b or FGF8b) and loss of function of PTEN tumor suppressor] were recapitulated into a new combinatorial mouse model. This model harboring the Fgf8b transgene and haploinsufficiency in Pten, both in a prostate epithelium-specific manner, yielded prostatic adenocarcinoma with readily detectable lymph node metastases, whereas single models with each of the defects were shown earlier to progress generally only up to prostatic intraepithelial neoplasia (PIN). In addition to late age-related development of typical adenocarcinoma, the model also displayed a low incidence of mucinous adenocarcinoma, a rare variant type of human prostatic adenocarcinoma. The cooperation between FGF8b activation and PTEN deficiency must be linked to acquisition of additional genetic alterations for the progression of the lesions to primary adenocarcinoma. Here, we identified loss of heterozygosity at the Pten gene leading to bialleic loss, as a necessary secondary event, indicating that a complete loss of PTEN function is required in the development of invasive cancer in the model. Analyses of expression of downstream mediators phospho-AKT (p-AKT) and p27(KIP1), in various types of lesions, however, revealed a complex picture. Although PIN lesions displayed relatively strong expression of p-AKT and p27(KIP1), there was a notable heterogeneity with variable decrease in their immunostaining in adenocarcinomas. Together, the results further underscore the notion that besides activation of AKT by loss of PTEN function, other PTEN-regulated pathways must be operative for progression of lesions from PIN to adenocarcinoma. 相似文献
109.
110.
Crude extracts of Cicer arietinum seedlings contain enzymes that mediate the oxidation of tryptophan. The most active is formylase followed by tryptophan oxygenase and kynureninase. Tryptophan is also utilized for the synthesis of indolyl-3-acetic acid. The stimulation of tryptophan oxygenase in seedlings incubated in presnece of indolyl-3-acetic acid has been shown by specific labelling of haem moeity and the apoenzyme not to involve de novo synthesis. 相似文献