全文获取类型
收费全文 | 395645篇 |
免费 | 13178篇 |
国内免费 | 978篇 |
专业分类
耳鼻咽喉 | 6167篇 |
儿科学 | 13407篇 |
妇产科学 | 10914篇 |
基础医学 | 52625篇 |
口腔科学 | 12662篇 |
临床医学 | 27661篇 |
内科学 | 81580篇 |
皮肤病学 | 10943篇 |
神经病学 | 28321篇 |
特种医学 | 14998篇 |
外国民族医学 | 101篇 |
外科学 | 53257篇 |
综合类 | 2237篇 |
一般理论 | 60篇 |
预防医学 | 37791篇 |
眼科学 | 8905篇 |
药学 | 28556篇 |
2篇 | |
中国医学 | 1193篇 |
肿瘤学 | 18421篇 |
出版年
2022年 | 1967篇 |
2021年 | 4982篇 |
2020年 | 2607篇 |
2019年 | 4840篇 |
2018年 | 10475篇 |
2017年 | 8020篇 |
2016年 | 7095篇 |
2015年 | 8850篇 |
2014年 | 9653篇 |
2013年 | 11834篇 |
2012年 | 23002篇 |
2011年 | 19276篇 |
2010年 | 9773篇 |
2009年 | 9354篇 |
2008年 | 13638篇 |
2007年 | 14982篇 |
2006年 | 14520篇 |
2005年 | 22254篇 |
2004年 | 22795篇 |
2003年 | 17826篇 |
2002年 | 12600篇 |
2001年 | 10454篇 |
2000年 | 8730篇 |
1999年 | 10971篇 |
1998年 | 1637篇 |
1992年 | 8901篇 |
1991年 | 8843篇 |
1990年 | 8940篇 |
1989年 | 8288篇 |
1988年 | 7739篇 |
1987年 | 7411篇 |
1986年 | 7135篇 |
1985年 | 6314篇 |
1984年 | 4379篇 |
1983年 | 3595篇 |
1979年 | 4665篇 |
1978年 | 2893篇 |
1977年 | 2209篇 |
1976年 | 2042篇 |
1975年 | 3025篇 |
1974年 | 3877篇 |
1973年 | 3499篇 |
1972年 | 3416篇 |
1971年 | 3378篇 |
1970年 | 3225篇 |
1969年 | 3102篇 |
1968年 | 2862篇 |
1967年 | 2743篇 |
1966年 | 2367篇 |
1965年 | 1435篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Summary In this study, the largest Nordic study of its kind, investigated psychosexual dysfunction among subjects aged 55–57 years. The cohort included 862 subjects of both sexes and all were interviewed using the Diagnostic Interview Schedule (DIS). Results showed that 122 subjects had a lifetime diagnosis of psychosexual dysfunction. The lifetime prevalence of psychosexual dysfunction was 14.4%; of inhibited sexual desire, 9.8%; of inhibited sexual excitement, 3.5%; of inhibited orgasm, 2.1%; and of functional dyspareunia, 1.3%. Of the subjects with psychosexual dysfunction, 73% were women. The frequency was highest in those who had never married. Separated subjects had rates intermediate between the married and the never-married. The majority (76%) of affected subjects had only one dysfunction. However, 57% of them had received another psychiatric diagnosis at some time. Subjects with psychosexual dysfunction wereless frequently diagnosed as suffering from alcohol abuse and dependence and social phobia than subjects with no psychosexual dysfunction. 相似文献
992.
993.
994.
Hypertension in developing countries 总被引:2,自引:0,他引:2
A Nissinen S B?thig H Granroth A D Lopez 《Rapport trimestriel de statistiques sanitaires mondiales》1988,41(3-4):141-154
Population surveys carried out since the 1970s in 15 developing countries including 23 population groups show that the prevalence of hypertension ranges from as low as 1% in some African countries to over 30% in Brazil. A trend analysis of the mortality statistics for 35-74 year-olds from 16 countries in which data are available shows a downward trend in mortality from hypertension and cerebrovascular diseases in most of these countries. In spite of the current low prevalence in some countries, the total number of hypertensives in the developing world is high, and a cost assessment of possible antihypertensive drug treatment indicates that developing countries cannot afford the same drug treatment levels as developed countries. 相似文献
995.
Julien Fey André Dietrich Anne Cosset T. Desprez L. Maréchal-Drouard 《Current genetics》1997,32(5):358-360
Two identical “chloroplast-like” tRNAAsn genes, trnN1 and trnN2, have been identified in the potato (Solanum tuberosum) mitochondrial genome. The flanking sequences of trnN1 are unrelated to the corresponding authentic potato chloroplast regions, whilst those of trnN2 are very similar to the chloroplast sequences. The trnN1 copy is present in the mitochondrial genome of various plants whereas the second copy, trnN2, is absent from all the other plant genomes studied so far. Interestingly, both trnN copies are expressed in potato mitochondria. Sequences flanking the chloroplast-like tRNAHis gene (trnH), present as a single copy in the potato mitochondrial DNA, are unrelated to the corresponding chloroplast sequences, whereas
chloroplast-derived sequences have been maintained in the vicinity of the maize chloroplast-like mitochondrial trnH gene. However, both the potato and the maize trnH are expressed in mitochondria.
Received: 10 April / 1 August 1997 相似文献
996.
A Hjortrup C S?rensen S Mejdahl M Horsnaes P Kjersgaard 《Acta orthopaedica Scandinavica》1990,61(2):152-153
Totally, 185 patients, operated on for a fresh hip fracture, were randomly allocated to either methicillin antibiotic prophylaxis or no prophylaxis and followed for 1 month. Two superficial wound infections were recorded in the prophylaxis group and one in the control group. Prophylactic use of antibiotics in surgery for hip fractures seems unnecessary provided strict aseptic routines in the operating room are followed. 相似文献
997.
Reports of the human teratogenicity of retinoids have raised concern about the potential human teratogenicity of high doses of vitamin A. Nevertheless, there are few human case reports of excess intake of vitamin A during pregnancy and defective outcomes. No epidemiological studies have been carried out on this subject. Here we present the results of an epidemiological study of prenatal exposure to high doses of vitamin A in Spain, using data from the Spanish hospital-based, case-control registry. Although it is difficult to reach conclusions with such a very low exposure level (1.3 per 1,000 livebirths), our results suggest that a teratogenic effect might exist for exposures to high doses of vitamin A (OR = 0.5, p = 0.15 for less than 40,000 FU and OR = 2.7, p = 0.06 for 40,000 1U or more). As we might expect, this effect also seems to be related to the organogenetic status (OR = 5.4, p = 0.1 for 1st –2nd month, OR = 1.8, p = 0.4 for 3rd onwards) at the time of exposure. 相似文献
998.
H Lomícková B Br?nová B Kubistová S Rodny A Zobanová M Odehnal P Zoban 《Ceskoslovenská oftalmologie》1990,46(6):401-410
The authors give an account of 190 premature infants they treated in 1956-1988, suffering from retinopathy of prematurity--ROP, and for prolonged subsequent periods. As the head of the team followed up all the children, there is an integrated view of the problem. The birth weight of the infants was 640 g--1,900 g. From the total number 76.8% infants had a birth weight of 1,500 g or less, 13.7% had a birthweight of 1,000 g or less. Evidence of the increasing rate is provided by the number of patients treated since birth at the department for premature and pathological infants FNM as well as by the number of children admitted from other departments after development of ROP. In 1956-1970, i. e. in 15 years, the authors looked after 34 patients, in 1971-1988, i. e. in 18 years there were 156 children with ROP. In 1956-70 cases of ROP predominated which developed as a result of absolute or relative hypoxia. They were successfully treated by individually adjusted and carefully controlled oxygen therapy (6.9% blind children). In 1971-1975 the possibility to use this therapy declined briskly because after introduction of modern medical technique the number of findings suggesting a hyperoxic insult increased. At that time the results deteriorated greatly (50% blind children). In 1976-1980 the results were favourably influenced by individual dosage of oxygen therapy in all infants, based on regular monitoring of blood gases (10.5% blind children).(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
999.
M R L?wik G Van Poppel M Wedel H van den Berg J Schrijver 《The Journal of nutrition》1990,120(11):1344-1351
To obtain more insight into the effect of moderate alcohol intake on vitamin B-6 status indicators, we studied the associations of alcohol intake (unadjusted and adjusted for intake of vitamin B-6 and protein) with the erythrocyte aspartate aminotransferase activation coefficient (EAST-AC) and plasma pyridoxal 5'-phosphate (PLP) level. Data obtained from men (n = 224) and women (n = 217) aged 65-79 (nationwide sample in the Netherlands) were used for this purpose. Although alcohol intake (a maximum of 21% of the energy came from alcohol) tended to be positively associated with PLP, this association never reached statistical significance (p greater than or equal to 0.05). EAST-AC was inversely associated with alcohol intake, whether or not it was adjusted for vitamin B-6 and protein intake. Similar results were found for the total EAST activity (after adding PLP) or apoenzyme activity; the basal EAST activity (before adding PLP) or holoenzyme activity was not associated with the alcohol intake. These results indicate that caution is needed in the interpretation of the specificity of EAST-AC (i.e., the degree to which EAST-AC is unaffected by other factors) as an indicator of vitamin B-6 intake. 相似文献
1000.
The results of treatment of 160 patients with coccygodynia were analysed. The condition was caused by contusion, fracture or dislocation of coccygeal vertebrae or excess of osteochondral tissue around the coccyx. The patients were treated conservatively and surgically, 56 and 104 respectively. In 94 cases (50,3%) of surgically treated complete recovery was achieved. Surgery should be undertaken in cases not responding to conservative measures. 相似文献