全文获取类型
收费全文 | 2630760篇 |
免费 | 213513篇 |
国内免费 | 4897篇 |
专业分类
耳鼻咽喉 | 35848篇 |
儿科学 | 87611篇 |
妇产科学 | 74895篇 |
基础医学 | 374173篇 |
口腔科学 | 75582篇 |
临床医学 | 236363篇 |
内科学 | 515572篇 |
皮肤病学 | 58610篇 |
神经病学 | 215988篇 |
特种医学 | 103115篇 |
外国民族医学 | 897篇 |
外科学 | 395493篇 |
综合类 | 64776篇 |
现状与发展 | 6篇 |
一般理论 | 970篇 |
预防医学 | 207248篇 |
眼科学 | 60893篇 |
药学 | 192580篇 |
3篇 | |
中国医学 | 5477篇 |
肿瘤学 | 143070篇 |
出版年
2018年 | 27433篇 |
2017年 | 21083篇 |
2016年 | 23762篇 |
2015年 | 27020篇 |
2014年 | 37925篇 |
2013年 | 57290篇 |
2012年 | 77426篇 |
2011年 | 81813篇 |
2010年 | 48319篇 |
2009年 | 46182篇 |
2008年 | 76966篇 |
2007年 | 81376篇 |
2006年 | 82627篇 |
2005年 | 80184篇 |
2004年 | 77755篇 |
2003年 | 74366篇 |
2002年 | 72283篇 |
2001年 | 125888篇 |
2000年 | 129510篇 |
1999年 | 108834篇 |
1998年 | 30515篇 |
1997年 | 27621篇 |
1996年 | 27561篇 |
1995年 | 26499篇 |
1994年 | 24509篇 |
1993年 | 23157篇 |
1992年 | 86262篇 |
1991年 | 83153篇 |
1990年 | 80624篇 |
1989年 | 77492篇 |
1988年 | 71814篇 |
1987年 | 70481篇 |
1986年 | 66629篇 |
1985年 | 63897篇 |
1984年 | 48289篇 |
1983年 | 41322篇 |
1982年 | 24724篇 |
1981年 | 22043篇 |
1979年 | 44742篇 |
1978年 | 31268篇 |
1977年 | 26309篇 |
1976年 | 24782篇 |
1975年 | 25742篇 |
1974年 | 31465篇 |
1973年 | 30381篇 |
1972年 | 28060篇 |
1971年 | 26127篇 |
1970年 | 24421篇 |
1969年 | 22751篇 |
1968年 | 21050篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
L R?stam R V Luepker M B Mittelmark D M Murray J S Slater H Blackburn 《American journal of preventive medicine》1988,4(5):249-254
To determine the potential effect of screening on referral patterns, an adult population sample (4,404 men, 5,164 women, 20-69 years of age) was systematically recruited and screened for hypercholesterolemia and then analyzed by different cholesterol referral recommendations. Using levels suggested by the Lipid Research Clinics Coronary Primary Prevention Trial (greater than or equal to 265 mg/dL), 7.3% of men and 5.8% of women would be referred for follow-up. With the suggested recommendations of the National Cholesterol Education Program (NCEP), (greater than or equal to 200 mg/dL), 49.2% of men and 40.2% of women would be referred. The use of age-related definitions of the NIH Consensus Conference on Lipid Lowering results in 28.0% referrals in men and 21.8% in women. From this population, hypercholesterolemia subjects (greater than or equal to 265 mg/dL at screening; n = 624) were invited for a second cholesterol determination (58% returned), which found 36% below the 265 mg/dL level. Population screening for cholesterol is likely to produce large numbers of patients for follow-up, with the actual numbers strongly dependent on cutoff levels and age-sex distributions. Referral and follow-up of these patients may place a significant load on an unprepared health care community. 相似文献
992.
993.
The predominant causative organism of whooping cough in Australia is of a serotype which has normally been associated overseas with unvaccinated communities. Australian DTP vaccines pass the statutory mouse test for Bordetella pertussis potency but this test is now believed to be relatively insensitive to certain factors, especially the major type-specific agglutinogens, which are presumably also important in the human host-parasite relationship. Because endemic B. bronchiseptica infections make some laboratory animals unsatisfactory for testing B. pertussis agglutinin responses, we have developed a test in which young farm sheep were immunized with vaccines. Type-specific agglutinins in their sera were assayed after absorption of non-specific agglutinins by suspensions of selected bordetella strains. Three well-reputed European DTP vaccines and two recent batches of Australian DTP vaccine were tested and compared thus. All evoked significant agglutinin responses to the main agglutinogens. 相似文献
994.
C J Van Binsbergen J Odink H Van den Berg H Koppeschaar H J Coelingh Bennink 《European journal of clinical nutrition》1988,42(11):929-937
Routine clinical chemical variables and parameters of the vitamin, iron and zinc status were measured in 20 female patients with anorexia nervosa (AN) and in 10 lean and 10 normal weight, healthy, female control subjects. Patients with AN had higher activities of L-gamma-glutamyl transferase (gamma-GT) and glutamate pyruvate transaminase (SGPT) and a higher concentration of prealbumin in serum and lower leucocyte and lymphocyte counts in blood. For the other routine clinical chemical parameters no significant differences between the groups were observed. AN patients had higher serum vitamin B12 and retinol levels. No significant differences were found for the status parameters of thiamin, vitamin B6, vitamin C, folate, vitamin E and vitamin D. Contradictory results were obtained for the riboflavin status: AN patients had a lower level of flavin adenine dinucleotide (FAD) in blood and a lower stimulation ratio of the glutathione reductase activity in erythrocytes (alpha-EGR). Patients with AN had higher serum ferritin concentration and lower total iron binding capacity (TIBC). However, haemoglobin (Hb), haematocrit (Ht) and iron saturation were not significantly different. No significant difference was found in the concentration of zinc in plasma. In spite of the poor intake of nutrients and energy, the results obtained did not indicate an inadequate status of vitamins, iron and zinc in patients with AN. 相似文献
995.
996.
997.
Severe herpetic keratitis. I: Prevalence of visual impairment in a clinic population. 总被引:1,自引:1,他引:0
下载免费PDF全文
![点击此处可从《The British journal of ophthalmology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
We report a prevalence study of the best visual acuity in the affected eye of 100 selected patients with herpetic keratitis seen during a two-year period. Sixty-two patients retained an acuity of 6/9 or better without requiring penetrating keratoplasty (PK). The prevalence of reduced visual acuity severe enough to warrant PK was 33%. Patients requiring PK for whom full clinical records were available suffered a mean of 6.8 episodes of keratitis. In this group of patients the vision of 18 fell from 6/6 to 6/60 over a mean period of 8.5 years. Once visual acuity was permanently reduced to 6/12, 78% of patients proceeded to lose vision to 6/60. Unilateral visual impairment occurs in at least a third of patients with severe herpetic keratitis. Once vision falls permanently to 6/12, the long-term prognosis for vision appears to be poor. 相似文献
998.
999.
The response of single detergent treated bovine retinal pigment epithelial cells in culture to ATP was measured with an image analyser. The most pronounced contraction was produced by 1.0 mM ATP with most change taking place in the first 10 min. At 1 h the area had decreased by about 33%, perimeter 22% and maximum length 25%. By way of comparison rabbit skin fibroblasts had a decreased area of approximately 40%, perimeter 25% and maximum length 22%. Bovine aortic smooth muscle cells on the other hand decreased in area by 55%, perimeter 40% and maximum length 36%. It is hoped that this assay may be used to evaluate drugs which could counteract contractile events in proliferative vitreoretinopathy. 相似文献
1000.
G F Watts L Gregory R Naoumova C Kubal K M Shaw 《European journal of clinical nutrition》1988,42(8):697-702
The onset of diabetic nephropathy is characterized by subclinical elevation of urinary albumin excretion, so-called 'microalbuminuria' (M). Dietary assessments were carried out in 15 insulin-dependent diabetic patients with persistent M and an equal number with persistently normal albumin excretion. The groups were matched for sex, age, duration of diabetes, body mass index, insulin dose and glycosylated haemoglobin; there were no significant differences in systemic blood pressure, glomerular filtration rate, blood glucose and serum albumin concentrations between the groups; retinopathy was significantly more frequent in patients with M. Diabetics with persistent M were found to consume a significantly larger amount of fat (expressed as grams and percentage of total energy) and a significantly smaller percentage of total energy as carbohydrate than patients with normal albumin excretion; total dietary energy was larger in those with persistent M, but the difference was not significant. No significant differences were found in protein and fibre intakes between the groups. Our findings suggest that an excess in the dietary consumption of fat relative to carbohydrate might play an important role in the pathogenesis of early nephropathy in insulin-dependent diabetes mellitus. We emphasize the importance of careful attention to nutrient intake in the prevention and treatment of diabetic complications. 相似文献