全文获取类型
收费全文 | 38020篇 |
免费 | 3822篇 |
国内免费 | 428篇 |
专业分类
耳鼻咽喉 | 580篇 |
儿科学 | 6590篇 |
妇产科学 | 246篇 |
基础医学 | 2852篇 |
口腔科学 | 1123篇 |
临床医学 | 4680篇 |
内科学 | 3544篇 |
皮肤病学 | 441篇 |
神经病学 | 1856篇 |
特种医学 | 506篇 |
外科学 | 2158篇 |
综合类 | 4271篇 |
现状与发展 | 2篇 |
一般理论 | 2篇 |
预防医学 | 8013篇 |
眼科学 | 1015篇 |
药学 | 2827篇 |
43篇 | |
中国医学 | 916篇 |
肿瘤学 | 605篇 |
出版年
2025年 | 38篇 |
2024年 | 694篇 |
2023年 | 869篇 |
2022年 | 1323篇 |
2021年 | 1814篇 |
2020年 | 1861篇 |
2019年 | 1510篇 |
2018年 | 1340篇 |
2017年 | 1548篇 |
2016年 | 1678篇 |
2015年 | 1416篇 |
2014年 | 2336篇 |
2013年 | 3201篇 |
2012年 | 2177篇 |
2011年 | 2294篇 |
2010年 | 1919篇 |
2009年 | 1682篇 |
2008年 | 1591篇 |
2007年 | 1688篇 |
2006年 | 1493篇 |
2005年 | 1329篇 |
2004年 | 1122篇 |
2003年 | 902篇 |
2002年 | 822篇 |
2001年 | 696篇 |
2000年 | 537篇 |
1999年 | 449篇 |
1998年 | 501篇 |
1997年 | 438篇 |
1996年 | 385篇 |
1995年 | 304篇 |
1994年 | 301篇 |
1993年 | 238篇 |
1992年 | 182篇 |
1991年 | 185篇 |
1990年 | 163篇 |
1989年 | 159篇 |
1988年 | 132篇 |
1987年 | 98篇 |
1986年 | 131篇 |
1985年 | 99篇 |
1984年 | 77篇 |
1983年 | 74篇 |
1982年 | 57篇 |
1981年 | 60篇 |
1980年 | 57篇 |
1979年 | 51篇 |
1978年 | 36篇 |
1977年 | 33篇 |
1976年 | 54篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
11.
Abstract Caries experience and enamel fluorosis prevalence in 8-year-old children belonging to different socio-economic classes were determined in two Chilean twin cities that are served by optimally fluoridated community water from the same waterworks facility. Low socio-economic status (LSES) children had a higher mean dm ft and DMFT indices (P<0.001) than high socioeconomic status (HSES) children. Prevalence of enamel fluorosis in the permanent teeth of LSES children was 0.79, significantly higher (X2= 9.0; P<0.003) than the value 0.59 found in HSES children. The proportion of Dean's scores 2. 3, 4 and 5 in first molars, mandibular and maxillary incisors in LSES children was higher than in HSES children (P<0.001). Differences in prevalence and seventy of enamel fluorosis between both groups are tentatively attributed lo a different pattern of tap water and tea consumption at pre-school ages. Suggestions are advanced to minimize the undesirable prevalence and severity of enamel fluorosis. 相似文献
12.
Abstract Maxillary and mandibular anterior permanent teeth in 38 children aged 7–12 years were examined 2 × with an interval of 2 years to determine whether spontaneous facial/lingual tooth position changes were related to alterations of the widths of keratinized and attached gingiva and the clinical crown height. Measurements included dental plaque, gingival inflammation, probing depth, and width of keratinized and attached gingiva. In addition, study casts from the baseline and 2-year examinations were used to measure clinical crown height and tooth position. The results showed that significant alterations in the widths of the keratinized and attached gingiva took place when the teeth changed positions in facial or lingual directions. The changes in gingival widths could to some extent be coupled to changes in clinical crown height. In teeth moving lingually, the gingival widths increased and the clinical crown height decreased. In teeth moving facially, the gingival widths decreased, and the facial gingiva sometimes receded. These gingival alterations call for examination of the facial gingiva as part of the monitoring of the development of the permanent dentition. 相似文献
13.
Kindergarten and first grade: A time for developing and nurturing gifted behaviors in young children
Patti L. Chance 《Early child development and care》1990,63(1):75-81
This article concludes that there is a tremendous need for gifted programs at the kindergarten and first grade levels. A review of the literature suggests that it is difficult to identify young gifted children through traditional screening techniques. The author concludes that Renzulli's Enrichment Triad Model may prove useful for identifying young gifted children. 相似文献
14.
A retrospective review was done of 69 children and adolescents (7-17 years old) who underwent 75 arthroscopies of the knee during a 5-year period. Girls were overrepresented (71%). Thirty-eight were children under the age of 16. Of 46 injuries, 34 (74%) happened during sports. Children and adolescents were divided into two age groups based on their presumed state of skeletal maturity (boys 9–15 and girls 7–14 in group I and boys 16–17 and girls 15–17 in group II); meniscal lesions were equally common in the two groups, whereas anterior cruciate ligament tears were more common in older children (NS). Eleven of 17 (65%) anterior cruciate ligament lesions were combined with other intra-articular pathology, most often meniscal tears (9/11). As in other studies, half of the prearthroscopic diagnoses were incorrect. A high frequency of incorrect prearthroscopic diagnoses and of combined lesions justifies arthroscopy as an important diagnostic tool in children and adolescents with a history of twisting knee injury or chronic nonspecific knee problems. Girls practising ball games seem to be especially prone to knee injuries leading to arthroscopy. 相似文献
15.
Comparison of three immunoassays for diagnosing sensitization to latex in children with spina bifida
B. Niggemann T. Michael A. von Moers U. Seidel R. Wahl L Jacobsen D. Scheffer U. Wahn 《Pediatric allergy and immunology》1996,7(4):164-166
As natural rubber latex (latex) has become more widespread in our environment, physicians have become increasingly aware of the problem of possible allergic reactions. Many fatal and near-fatal incidents have been reported (mainly during surgery) (1—3) and data has been published on groups frequently exposed to latex, such as patients with spina bifida (4—9), healthcare professionals (10—12) and occupationally exposed persons (13). The incidence of latex allergy in children seems to be increasing (14). Tests are therefore needed which can reliably detect sensitization to latex. Our aim was to compare the diagnostic accuracy of three commercial immunoassays for measuring specific IgE in serum to latex. 相似文献
16.
A. Molina-Carballo A. Munoz-Hoyos J.A. Martin-Garcia J. Uberos-Feritindez T. Rodriguez-Cabezas D. Acuna-Castroviejo 《Journal of pineal research》1996,21(2):73-79
Abstract: It seems clear that the pineal hormone, melatonin (N-acetyl-5-methoxytryptamine), is involved in the reproductive behavior of several animal species including humans. Moreover, several data also support a role for 5-methoxytryptophol (ML), another pineal hormone, in the control of sexual processes. To test the role of ML in human reproductive axis, 128 healthy children, 68 boys and 60 girls, were studied. Each of these groups was divided in three age subgroups of 6, 11, and 14 years. A single blood sample (0900 hours) was obtained from each subject to determine melatonin, ML, FSH, LH, estradiol (girls), and testoterone (boys) by RIA. Statistical analysis of the data included ANOVA-II (factor I: age, factor II: sex) and an analysis of covariance with age as covariate. A similar plasma melatonin concentration, with a significant decrease between 6 and 11 years, was found in boys and girls. Melatonin concentrations correlate well with initiation of the pubertal development in these children, although no sex differences were found. Concentrations of ML are approximately 50% of those of melatonin. In contrast to melatonin, ML levels show significant age and sex differences. Plasma ML concentration significantly increased in boys ( P < 0.001) and decreased in girls (P < 0.001) after 8 years of age. These results support the hypothesis that, besides melatonin, other pineal compounds such as ML may be involved in the maturation process in humans. The pineal indole ML may also be used as a marker of the different chronobiology in the pubertal development in boys and girls. 相似文献
17.
Judith D. DePue Elizabeth L. McQuaid Daphne Koinis-Mitchell Christopher Camillo Anthony Alario Robert B. Klein 《The Journal of asthma》2007,44(6):449-453
Over 3 years, 972 families participated in an after-school asthma program at their child's school. Parents and children attended concurrent 21/2 -hour workshops. Parents were 74% Latino; 45% non-English speaking, with 77% of children on Medicaid. Asthma symptoms were significantly reduced, from multiple times per week to less than once per week on average. Oral steroid use decreased to one third of baseline use. Hospital days decreased from 11% to 2%; emergency visits decreased 35% to 4%; and school days missed decreased 48% to 20%. This program has now become sustainable with both private and Medicaid insurance coverage. 相似文献
18.
L. F. NIMRI 《Child: care, health and development》1994,20(4):231-237
Summary This cross-sectional study was conducted to investigate the prevalence of intestinal parasites among primary school children in Northern Jordan. Stool specimens were collected from 1100 children of both sexes from urban and rural schools. A questionnaire covering relevant informations was completed for each child. Wet mount preparation, formaline-ether concentration technique, and trichrome stain were prepared for the recovery and identification of parasites. Giardia lamblia was observed in 396 (36%) of the stool specimens examined. The infection rates were higher in the younger age group where several of them had diarrhoea and reported variable symptoms. The infection rates declined with age and children were asymptomatic. Rates were higher in children from the rural areas, from low income families, and it was higher in boys than girls.
Contaminated drinking water is suspected to be the major potential source of infection. The importance of the asymptomatic cases and the epidemiological factors contributing to the transmission in these areas are discussed. 相似文献
Contaminated drinking water is suspected to be the major potential source of infection. The importance of the asymptomatic cases and the epidemiological factors contributing to the transmission in these areas are discussed. 相似文献
19.
Serum immunoglobulins including IgG subclasses were measured in 73 unselected children with asthma. The results showed that 22 (30%) had partial IgA and/or IgG4 subclass deficiency. Clinical assessment showed that 21 children were infection-prone, and 52 were not. Further analysis showed that infection-prone children were significantly different from non-infection-prone children with regard to familial history of allergy (29% vs 60%, p = 0.015), elevated IgE (62% vs 33%, p = 0.021), IgA deficiency (38% vs 15%, p = 0.38) and IgG subclass deficiency (24% vs 4%, p = 0.018). These results suggest that there may be subgroups of children with asthma who are also immunodeficient. 相似文献
20.
B. Falk Y. Weinstein R. Dotan D. A. Abramson D. Mann-Segal J. R. Hoffman 《Scandinavian journal of medicine & science in sports》1996,6(5):259-264
Anaerobic power is characterized by a high degree of specificity regarding both the recruited muscles as well as the recruitment pattern. The popular Wingate Anaerobic Test (WAnT) is a cycling test that does not satisfy the need for a running-specific anaerobic test. We describe such a test, using a novel type of a commercially available treadmill (BRL 1800, Gymrol, France). The ergometer is equipped with a torque motor to neutralize the frictional resistance of the treadmill belt, and a hip-belt harness connected to a horizontal rod. Force applied to the harness is monitored by a strain gauge mounted on the rod, while vertical movement is monitored by a potentiometer at the posterior fixed end of the rod. These, in conjunction with the treadmill belt speed, enable the computation of horizontal and vertical power as well as the combined total output. Power is calculated both as 'peak' power (highest 2.5 s segment) and 'mean' power (20 s duration). Preliminary results of young athletes were generally consistent with the expected age-related changes in anaerobic power. Values obtained on the anaerobic treadmill were always higher than the corresponding WAnT values previously obtained in comparable age groups. The higher values were probably due to the larger muscle mass involved and the shorter peak and mean power durations (2.5 and 20 s versus 5 and 30 s in the WAnT, respectively). This test should enable not only running-specific anaerobic power monitoring but also the characterization of the relationship between the horizontal and vertical components of that power. 相似文献