全文获取类型
收费全文 | 1167篇 |
免费 | 49篇 |
国内免费 | 68篇 |
专业分类
耳鼻咽喉 | 3篇 |
儿科学 | 41篇 |
妇产科学 | 34篇 |
基础医学 | 94篇 |
口腔科学 | 9篇 |
临床医学 | 199篇 |
内科学 | 168篇 |
皮肤病学 | 13篇 |
神经病学 | 34篇 |
特种医学 | 139篇 |
外科学 | 75篇 |
综合类 | 28篇 |
预防医学 | 162篇 |
眼科学 | 2篇 |
药学 | 78篇 |
肿瘤学 | 205篇 |
出版年
2022年 | 7篇 |
2021年 | 11篇 |
2020年 | 2篇 |
2019年 | 15篇 |
2018年 | 7篇 |
2017年 | 11篇 |
2016年 | 12篇 |
2015年 | 16篇 |
2014年 | 21篇 |
2013年 | 28篇 |
2012年 | 43篇 |
2011年 | 37篇 |
2010年 | 43篇 |
2009年 | 44篇 |
2008年 | 59篇 |
2007年 | 99篇 |
2006年 | 43篇 |
2005年 | 35篇 |
2004年 | 38篇 |
2003年 | 39篇 |
2002年 | 26篇 |
2001年 | 43篇 |
2000年 | 40篇 |
1999年 | 33篇 |
1998年 | 29篇 |
1997年 | 41篇 |
1996年 | 31篇 |
1995年 | 28篇 |
1994年 | 41篇 |
1993年 | 35篇 |
1992年 | 42篇 |
1991年 | 23篇 |
1990年 | 27篇 |
1989年 | 24篇 |
1988年 | 36篇 |
1987年 | 28篇 |
1986年 | 17篇 |
1985年 | 20篇 |
1984年 | 10篇 |
1983年 | 7篇 |
1982年 | 15篇 |
1981年 | 7篇 |
1980年 | 13篇 |
1979年 | 6篇 |
1978年 | 8篇 |
1977年 | 11篇 |
1976年 | 11篇 |
1975年 | 14篇 |
1973年 | 2篇 |
1971年 | 2篇 |
排序方式: 共有1284条查询结果,搜索用时 15 毫秒
1.
2.
Emmanuel Blot Elsie Staub 《Journal of clinical oncology》2003,21(20):3887; author reply 3887-3887; author reply 3888
3.
4.
AR Jones BSC AJP Sandison FRCS WJ Owen MS FRCS 《International journal of clinical practice》1997,51(5):294-295
Pre-clerking of all patients undergoing elective general surgical operations was introduced at our hospital in an attempt to reduce an unacceptably high operation cancellation rate. A prospective audit has been performed on the effect of this policy on the cancellation rate. Before the introduction of pre-clerking there was a marked seasonal variation in the number of patients who failed to attend for surgery, which could be explained by absence on holiday. This seasonal variation disappeared after the start of pre-clerking clinics, but there has been no reduction in the number of cancellations for medical reasons. 相似文献
5.
Lung cancer and prior tuberculosis infection in Shanghai 总被引:1,自引:0,他引:1
W Zheng W J Blot M L Liao Z X Wang L I Levin J J Zhao J F Fraumeni Y T Gao 《British journal of cancer》1987,56(4):501-504
In a population-based case-control study of lung cancer in Shanghai involving interviews during 1984-86 with 1,405 cancer patients and 1,495 controls, a significant 50% elevation in the risk of lung cancer, adjusted for cigarette smoking, was observed among persons who had a history of tuberculosis. Among those diagnosed with tuberculosis within the past 20 years, the risk exceeded 2.5-fold. In males the lung cancers tended to occur on the same side as the previous tuberculosis infection. For both sexes, the effect of recent tuberculosis was most apparent for adenocarcinoma and peripheral tumours. No relationship was found between lung cancer risk and the type of tuberculosis therapy, including use of isoniazid. The findings suggest that tuberculosis may predispose to lung cancer, with the association most apparent among recent survivors of the infection. 相似文献
6.
Berbaum KS; el-Khoury GY; Franken EA Jr; Kathol M; Montgomery WJ; Hesson W 《Radiology》1988,168(2):507-511
The effect of knowledge of localizing symptoms and signs in the detection of fractures was studied. Forty radiographs of the extremities were examined twice by seven radiologists; the sessions were separated by 4 months. In 26 cases, a subtle fracture was present; 14 cases were normal. In half of the cases at each session, the precise location of pain, tenderness, or swelling was provided. The observer was asked to determine if the case was normal or abnormal (provide the exact location of the fracture) and to indicate the degree of confidence in the diagnosis. Responses were converted to a numeric scale for analysis. Analysis of receiver operator characteristic parameters indicates that clues regarding location of trauma facilitate detection of fractures. The improvement is based largely on an increased true-positive rate without an increased false-positive rate, regardless of the decision criteria of the radiologist (overall willingness to "overread" or "underread"). This has direct clinical applicability and reinforces the plea of radiologists for precise clinical information. 相似文献
7.
Lei Wan, Poliporus mylittae Cook et Mass(Omphalia lapidescena Scbraet) is a kind of fungus used in traditional Chinese medicine, as an antheiminthie From Lei Wan, an "active component designated as. S-4001 had been isolated.Preliminary results indicate that S-4001 belongs to D, β, 1-3 glucan with some 1-6 linkages.After administration of S-4001, significant antiinflammatory activity was found in various experimental animal models, including croton oil induced ear edema in mice and agar or yeast induced ankle swelling in rats. An inhibitory action on leucocyte migration inducced by intraperitoneal injection of CMC in rats was also observed. The plasma content of corticosterone was significantly increased, but the content of ascorbic acid in the adrenals did not change in rats given S-4001. Apart from these actions, S-4001 showed a number of immunostimulating actions such as increasing the clearance of Congo red from mice blood and potentiating the immunohemolysis reaction in 615 mice. 相似文献
8.
Background
There is currently an unprecedented expressed need and demand for estimates of maternal mortality in developing countries. This has been stimulated in part by the creation of a Millennium Development Goal that will be judged partly on the basis of reductions in maternal mortality by 2015. 相似文献9.
Placental pathologic changes in malaria. A histologic and ultrastructural study. 总被引:12,自引:2,他引:12 下载免费PDF全文
Placenta malarial changes (PMCs) related to maternal plasmodium infection were present in 33% (247 cases) of a series of 741 placentas collected from an unselected population living in an area of high malarial endemicity (Haut-Ogooué, Gabon, Africa). Plasmodia were found on material thick blood films taken at the time of delivery in 42% of the women with and 24% of women without associated PMCs. Plasmodium falciparum was the most frequent infecting organism. PMCs were more frequent and, in general, more marked in primiparas. The primiparas were significantly (P less than 0.001) more numerous in the group with PMCs than in the control group without such changes. The mean weight of term placentas with malarial changes was significantly (46 g; P less than 0.001) less than that of placentas without such changes. The morphologic changes were a combination of the following features: 1) presence of parasites in the intervillous spaces; 2) macrophage concentration in the intervillous spaces; 3) malarial pigment deposits; 4) excess of perivillous fibrinoid deposits; 5) syncytiotrophoblastic damage; and 6) trophoblastic basal lamina thickening. Plasmodia were found in placental intervillous spaces in 42% (105/247). Local parasitemia varied in magnitude; in a few cases, 30% or more of the maternal erythrocytes were infected. Macrophage concentration in the intervillous spaces was present in 29% (72/247) and was always associated with local parasitemia. Macrophages phagocytized red blood cells and malarial pigment, and their number varied inversely with that of the local parasites. It seems, therefore, that macrophages play an important role in local parasite clearance. Malarial brown pigment was observed in all cases from the series. It had characteristic ultrastructural features and occurred in perivillous deposits of fibrinoid, in macrophages, or free in intervillous spaces. Excessive perivillous fibrinoid deposits were a constant histologic finding and were usually associated with syncytiotrophoblastic necrosis or ultrastructural damage such as partial microvilli loss, filamentous material accumulation in intracytoplasmic vacuoles, and "podocytelike" cytoplasmic projections on the basal surface. At these sites the trophoblastic basal lamina was usually thickened. Previously reported morphologic data and our own findings suggest that the peculiar placental changes in malaria, restricted to intervillous spaces and to villous surfaces, may be related to an immunopathologic process. 相似文献
10.
Lactate production in isolated perfused rat lung 总被引:1,自引:0,他引:1