全文获取类型
收费全文 | 721篇 |
免费 | 34篇 |
国内免费 | 67篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 27篇 |
妇产科学 | 11篇 |
基础医学 | 80篇 |
口腔科学 | 8篇 |
临床医学 | 99篇 |
内科学 | 198篇 |
皮肤病学 | 16篇 |
神经病学 | 16篇 |
特种医学 | 137篇 |
外国民族医学 | 1篇 |
外科学 | 40篇 |
综合类 | 27篇 |
预防医学 | 53篇 |
眼科学 | 3篇 |
药学 | 83篇 |
肿瘤学 | 21篇 |
出版年
2021年 | 4篇 |
2020年 | 3篇 |
2018年 | 4篇 |
2016年 | 9篇 |
2015年 | 9篇 |
2014年 | 13篇 |
2013年 | 25篇 |
2012年 | 18篇 |
2011年 | 23篇 |
2010年 | 34篇 |
2009年 | 30篇 |
2008年 | 30篇 |
2007年 | 67篇 |
2006年 | 20篇 |
2005年 | 12篇 |
2004年 | 18篇 |
2003年 | 16篇 |
2002年 | 18篇 |
2001年 | 11篇 |
2000年 | 20篇 |
1999年 | 16篇 |
1998年 | 25篇 |
1997年 | 36篇 |
1996年 | 25篇 |
1995年 | 27篇 |
1994年 | 23篇 |
1993年 | 22篇 |
1992年 | 14篇 |
1991年 | 19篇 |
1990年 | 24篇 |
1989年 | 27篇 |
1988年 | 26篇 |
1987年 | 15篇 |
1986年 | 15篇 |
1985年 | 16篇 |
1984年 | 7篇 |
1983年 | 10篇 |
1982年 | 11篇 |
1981年 | 8篇 |
1980年 | 9篇 |
1979年 | 2篇 |
1978年 | 7篇 |
1977年 | 9篇 |
1976年 | 9篇 |
1975年 | 10篇 |
1973年 | 2篇 |
1972年 | 3篇 |
1971年 | 3篇 |
1968年 | 3篇 |
1961年 | 2篇 |
排序方式: 共有822条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
D P Derman D Ballot T H Bothwell B J MacFarlane R D Baynes A P MacPhail M Gillooly J E Bothwell W R Bezwoda F Mayet 《The British journal of nutrition》1987,57(3):345-353
The absorption of iron from soya-bean (Glycine hispida)-based and milk-based infant formulas was assessed in 138 multiparous Indian women, using the erythrocyte utilization of radioactive Fe method. Fe absorption was significantly greater from the basal milk formula (1.5 g protein) than it was from the basal soya-bean formula (2.3 g protein), with geometric mean values of 0.083 and 0.044 respectively. Ascorbic acid markedly increased Fe absorption from the milk-based formula in a dose-dependent fashion. The increase was fivefold when the ascorbic acid:Fe ratio on a weight-for-weight basis was 6:1 and over tenfold when it was 20:1. In contrast, ascorbic acid had a less-marked effect on the absorption of Fe from the soya-bean-based formula, with only a two- to threefold increase at an ascorbic acid:Fe ratio of 20:1. The geometric mean Fe absorption from the soya-bean formula (1.27 mg Fe, 2.3 g isolated soya-bean protein (ISP] was somewhat less than that from the same amounts of ISP and ascorbic acid made up in milk (0.075 and 0.113 respectively). However, a direct comparison between the soya-bean formula in milk and in water showed no significant difference (0.043 and 0.060 respectively). Fe absorption from a drink containing 10 g ISP and 30 mg ascorbic acid was significantly better than that from a similar drink containing the soya-bean flour from which ISP is extracted (0.044 and 0.027 respectively). Heating ISP to 200 degrees for 2 h before its use had no effect on Fe availability.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
5.
Y K Seedat F G Mayet G H Latiff G Joubert 《Suid-Afrikaanse tydskrif vir geneeskunde》1992,82(4):251-256
Coronary heart disease (CHD) is still relatively uncommon in the black population of South Africa. We embarked on a study to determine the prevalence of risk factors leading to CHD in the black population of Durban. The study sample was selected from patients attending a dental clinic at a hospital. A total of 458 patients (age range 16-69 years) was studied. The prevalence of CHD was 2.4%. The percentage prevalences of selected risk factors were: hypertension (blood pressure > or = 140 mmHg systolic and/or > or = 90 mmHg diastolic) 28% (31.9% for males, 25.4% for females); protective levels of high-density lipoprotein/total cholesterol > or = 20%, 81.3%; diabetes mellitus 4.9% for males, 2.9% for females; smoking > or = 10 cigarettes per day 28.1% for males, 3.4% for females; obesity 3.7% for males 22.6% for females. We found the Minnesota Coding System for electrocardiographic changes of CHD and the Rose questionnaire to be unreliable for eliciting CHD in blacks. Hypercholesterolaemia is less common, and this may explain the low incidence of CHD in blacks. Epidemics of CHD as seen in Indian, coloured and white South Africans can still be prevented in the black population, but preventive measures must be instituted rapidly. 相似文献
6.
7.
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
8.
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
9.
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
10.