全文获取类型
收费全文 | 1962篇 |
免费 | 139篇 |
国内免费 | 6篇 |
专业分类
耳鼻咽喉 | 16篇 |
儿科学 | 121篇 |
妇产科学 | 29篇 |
基础医学 | 224篇 |
口腔科学 | 51篇 |
临床医学 | 138篇 |
内科学 | 426篇 |
皮肤病学 | 21篇 |
神经病学 | 122篇 |
特种医学 | 59篇 |
外科学 | 398篇 |
综合类 | 38篇 |
一般理论 | 13篇 |
预防医学 | 91篇 |
眼科学 | 52篇 |
药学 | 174篇 |
中国医学 | 2篇 |
肿瘤学 | 132篇 |
出版年
2023年 | 12篇 |
2022年 | 27篇 |
2021年 | 122篇 |
2020年 | 43篇 |
2019年 | 88篇 |
2018年 | 96篇 |
2017年 | 65篇 |
2016年 | 70篇 |
2015年 | 73篇 |
2014年 | 114篇 |
2013年 | 106篇 |
2012年 | 176篇 |
2011年 | 134篇 |
2010年 | 63篇 |
2009年 | 55篇 |
2008年 | 92篇 |
2007年 | 89篇 |
2006年 | 71篇 |
2005年 | 61篇 |
2004年 | 43篇 |
2003年 | 46篇 |
2002年 | 47篇 |
2001年 | 25篇 |
2000年 | 30篇 |
1999年 | 26篇 |
1998年 | 11篇 |
1996年 | 7篇 |
1995年 | 8篇 |
1994年 | 6篇 |
1992年 | 12篇 |
1991年 | 19篇 |
1990年 | 18篇 |
1989年 | 19篇 |
1988年 | 19篇 |
1987年 | 11篇 |
1986年 | 13篇 |
1985年 | 12篇 |
1984年 | 8篇 |
1983年 | 9篇 |
1981年 | 11篇 |
1980年 | 9篇 |
1979年 | 12篇 |
1978年 | 7篇 |
1976年 | 8篇 |
1974年 | 9篇 |
1973年 | 9篇 |
1972年 | 9篇 |
1971年 | 17篇 |
1970年 | 9篇 |
1967年 | 10篇 |
排序方式: 共有2107条查询结果,搜索用时 156 毫秒
11.
Bhatt AD Dalal DG Shah SJ Joshi BA Gajjar MN Vaidya RA Vaidya AB Antarkar DS 《Journal of postgraduate medicine》1995,41(1):5-7
An open comparative trial was conducted in 58 adult obese patients (Body Mass Index > or = 25 kg/square metre). Group I (n = 27), non-drug, was advised diet (1200-1600 cals) and a brisk walk for 30 minutes. Group II, in addition, received Guggulu (Medohar) 1.5-3 gms/day for 30 days. Mean difference in weight loss between Guggulu and non-drug group was 0.32 kg (ns) on day 15 and 0.58 kg on day 30 (ns). The mean weight reduction in patients (> 90 kgs) was 1.92 kg (ns) and 2.25 kg (ns) higher in Guggulu group. All patients weighing > 90 kg lost weight in Guggulu group whilst 3 in non-drug group did not lose weight. Guggulu was tolerated well. The data from this pilot study suggest a synergistic diet-Guggulu interaction over 30 days in patients weighing > 90 kgs which needs to be confirmed in a large placebo controlled study. 相似文献
12.
Tandemly arranged gene clusters of malarial parasites that are highly conserved and transcribed 总被引:7,自引:0,他引:7
A molecular clone containing a 5.8 kb Eco RI fragment was isolated from a genomic library of the rodent malarial parasite Plasmodium yoelii. The P. yoelii genome contains about 150 copies of this sequence, making up almost 3% of the DNA. These sequences are tandemly arrayed in head-to-tail configurations with the unit length of the repeat being 5.8 kb. Several poly(A+) RNAs of P. yoelii ranging from 1.6 to 0.3 kb are recognized by the 5.8 kb clone. Five additional species of malarial parasites (P. chabaudi, P. berghei, P. falciparum, P. knowlesi, and P. cynomolgi) contain tandemly repeated arrays of sequences having the same unit length of 5.8 kb, which readily hybridize to the sequence cloned from P. yoelii. 相似文献
13.
We present a mathematical model for pre-fusion interaction between an influenza virus and a healthy cell. Our model describes the role played by hemagglutinin (HA) protein clusters in bringing the viral membrane into close contact with the host cell membrane as a first step of the fusion process between the two membranes. The viral membrane is modelled as a lipid bilayer with bending rigidity. Using the calculus of variations, we compute the deformation of the viral membrane under the influence of HA protein clusters. Our numerical results support the hypothesis of dimple formation in the fusion site proposed in the literature. The asymmetric nature of the protein molecules due to various reasons such as tilting is the primary cause for the dimple formation. We discuss the effects of spontaneous curvature, the protein cluster radius, fusion-site size and the bending moment exerted by the protein cluster. We also examine the effects of membrane tension and the presence of a host cell on the dimple shape. Our results support previous experimental observations. 相似文献
14.
Pathology, microbiology, blood bank and other diagnostic laboratories generate sizable amount of biomedical waste (BMW). The audit of the BMW is required for planning proper strategies. The audit in our laboratory revealed 8 kgs anatomical waste, 600 kgs microbiology waste, 220 kgs waste sharps, 15 kgs soiled waste, 111 kgs solid waste, 480 litres liquid waste along with 33,000 litres per month liquid waste generated from labware washing and laboratory cleaning and 162 litres of chemical waste per month. Section wise details are described in the text. Needle sharps are collected in puncture proof containers and the needles autoclaved before sending to needle pit. The glass forms the major sharp category and is disinfected with hypochlorite before washing/recycling. All microbiology waste along with containers/plates/tubes are autoclaved before recycling/disposal. The problem of formalin fixed anatomical waste as histology specimens is pointed out. The formalin containing tissues cannot be sent for incineration for the fear of toxic gas release and the guidelines by the Biomedical waste rule makers need to be amended for the issue. The discarded/infected blood units in blood bank need to be autoclaved before disposal since chemical treatments are difficult or inefficient. The liquid waste management needs more attention and effluent treatment facility needs to be viewed seriously for hospital in general. The segregation of waste at source is the key step and reduction, reuse and recycling should be considered in proper perspectives. 相似文献
15.
16.
The placenta is an important functional unit for gas transfer between mother and fetus. The placental membrane, consisting of trophoblast layer interposed between maternal and fetal blood, plays an active role for intensity of respiration, but no morphological evidence has been documented. Until now, it has been reported that fetal growth retardation and increased fetal mortality rate usually could be seen at high altitude. In an attempt to find the cause of high perinatal mortality rate in Nepal, this study was undertaken to examine pathologically about 1000 Himalayan placentas obtained in Nepal and Tibet since 1977, and the results were compared with those of 5500 Japanese placentas at Saitama Medical School since 1990. In this study, characteristics of ultrastructural features of the Nepalese placental villi investigated in recent years are reported. (1) The gross characteristics of placental pathology in the Himalayan group were represented by marked subchorionic fibrin deposits and increased chorionic cysts in contrast to low incidence of intervillous thrombosis compared with those of the Japanese group. (2) As characteristics of histological findings of the placental villi between Himalayan and Japanese groups, the incidence of chorangiosis and chorangioma in the Himalayan group was significantly higher than that in the Japanese group. (3) Accompanying an increase of vasculosyncytial membrane (VSM) in the villi, thickness and separation of basement membrane of the syncytium in addition to increased apoptosis of syncytial cell nuclei were recognized. (4) As characteristic ultrastructural features of chorionic villi of Nepalese placentas, an increase of mitochondria and cystic formation of rough endoplasmic reticulum (rER), in addition to appearance of lamellar bodies similar to alveolar epithelial type II cell in organellae of the syncytium, were observed. These ultrastructural changes of the placental villous capillaries may be ascribed to hypevascularization caused by the chronic hypoxic state. It is, therefore, presumed that trophoblast cells may play an important role for gas transfer mecha-nism under such a hypoxic state at high altitude. 相似文献
17.
18.
19.
A member of a conserved Plasmodium protein family with membrane-attack complex/perforin (MACPF)-like domains localizes to the micronemes of sporozoites 总被引:11,自引:0,他引:11
Kaiser K Camargo N Coppens I Morrisey JM Vaidya AB Kappe SH 《Molecular and biochemical parasitology》2004,133(1):15-26
Pore-forming proteins are employed by many pathogens to achieve successful host colonization. Intracellular pathogens use pore-forming proteins to invade host cells, survive within and productively interact with host cells, and finally egress from host cells to infect new ones. The malaria-causing parasites of the genus Plasmodium evolved a number of life cycle stages that enter and replicate in distinct cell types within the mosquito vector and vertebrate host. Despite the fact that interaction with host-cell membranes is a central theme in the Plasmodium life cycle, little is known about parasite proteins that mediate such interactions. We identified a family of five related genes in the genome of the rodent malaria parasite Plasmodium yoelii encoding secreted proteins all bearing a single membrane-attack complex/perforin (MACPF)-like domain. Each protein is highly conserved among Plasmodium species. Gene expression analysis in P. yoelii and the human malaria parasite Plasmodium falciparum indicated that the family is not expressed in the parasites blood stages. However, one of the genes was significantly expressed in P. yoelii sporozoites, the stage transmitted by mosquito bite. The protein localized to the micronemes of sporozoites, organelles of the secretory invasion apparatus intimately involved in host-cell infection. MACPF-like proteins may play important roles in parasite interactions with the mosquito vector and transmission to the vertebrate host. 相似文献
20.
Jayant S. Vaidya 《Surgery (Oxford)》2021,39(4):193-201
Radiotherapy (or radiation therapy) uses ionizing radiation to selectively kill cancer cells, especially for solid tumours. Like surgery, it is meant to be a ‘local’ treatment, although its beneficial systemic effects are being discovered. It is most commonly used in addition to surgery (adjuvant, e.g. breast), but its role in the neoadjuvant setting in combination with chemotherapy for some cancers (e.g. rectum) is also established. In early stages of cancer, it can be the definitive treatment, avoiding surgery and enabling organ preservation (e.g. larynx), while in late stages, it can provide excellent palliation (e.g. bone metastasis). Radiotherapy can be delivered at various energy levels (kiloVolts, megaVolts), with various subatomic particles (e.g. electrons, protons, and high-energy electromagnetic radiation). The traditional bulky equipment (e.g. linear accelerator) needs to be housed in an underground bunker and uses complex imaging to improve precision and avoid radiation to normal tissues. Fractionated regimens spanning several days reduce individual doses. Modern techniques using mobile devices (e.g. TARGIT-IORT) can deliver radiotherapy during surgery with the highest precision and immediacy. 相似文献