全文获取类型
收费全文 | 8190篇 |
免费 | 547篇 |
国内免费 | 34篇 |
专业分类
耳鼻咽喉 | 48篇 |
儿科学 | 199篇 |
妇产科学 | 57篇 |
基础医学 | 497篇 |
口腔科学 | 42篇 |
临床医学 | 931篇 |
内科学 | 522篇 |
皮肤病学 | 95篇 |
神经病学 | 1070篇 |
特种医学 | 109篇 |
外科学 | 275篇 |
综合类 | 474篇 |
预防医学 | 3865篇 |
眼科学 | 23篇 |
药学 | 367篇 |
2篇 | |
中国医学 | 27篇 |
肿瘤学 | 168篇 |
出版年
2024年 | 15篇 |
2023年 | 112篇 |
2022年 | 186篇 |
2021年 | 238篇 |
2020年 | 272篇 |
2019年 | 326篇 |
2018年 | 323篇 |
2017年 | 255篇 |
2016年 | 228篇 |
2015年 | 269篇 |
2014年 | 678篇 |
2013年 | 866篇 |
2012年 | 636篇 |
2011年 | 638篇 |
2010年 | 505篇 |
2009年 | 496篇 |
2008年 | 443篇 |
2007年 | 387篇 |
2006年 | 330篇 |
2005年 | 219篇 |
2004年 | 180篇 |
2003年 | 136篇 |
2002年 | 106篇 |
2001年 | 87篇 |
2000年 | 88篇 |
1999年 | 66篇 |
1998年 | 70篇 |
1997年 | 60篇 |
1996年 | 61篇 |
1995年 | 50篇 |
1994年 | 43篇 |
1993年 | 32篇 |
1992年 | 42篇 |
1991年 | 34篇 |
1990年 | 22篇 |
1989年 | 23篇 |
1988年 | 39篇 |
1987年 | 25篇 |
1986年 | 27篇 |
1985年 | 23篇 |
1984年 | 24篇 |
1983年 | 25篇 |
1982年 | 24篇 |
1981年 | 12篇 |
1980年 | 15篇 |
1978年 | 8篇 |
1977年 | 8篇 |
1976年 | 5篇 |
1975年 | 5篇 |
1974年 | 5篇 |
排序方式: 共有8771条查询结果,搜索用时 15 毫秒
41.
A panel of 377 healthy adults and 920 COPD patients aged 30–65 years, is annually interviewed (ATS-NHLI health questionnaire) and performs pulmonary function test (PFT), which includes: FVC, FEVI, FEVl/FVC, PEF, FEF50 and FEF75. Baseline data analysis showed a more significant excess in respiratory symptmos (8.8% to 21.4%) and lower PFT (2.4% to 8.0%) among patients occupationally exposed to dust, than among healthy exposed panelists (-0.7% to 7.7% excess symptomatology and -0.3 to 5.8% lower PFT). Among patients a significant correlation between PFT and degree of occupational dust exposure was found. Significantly lower FEVl/FVC and excess in respiratory symptoms (with relative risks of 2.47–16.38) was present in healty smokers vs. non smokers as compared with COPD patients.Corresponding author. 相似文献
42.
I. Andersen K. B. Svenes 《International archives of occupational and environmental health》1989,61(4):289-295
Summary Lung specimens from 39 nickel refinery workers autopsied during the period from 1978 to 1984 were analyzed for nickel. Fifteen of the workers were employed in the Roasting and Smelting Department, where exposure to nickel was predominantly in the form of nickel-copper oxides, Ni3S2 and metallic dust. The remaining 24 men worked in the Electrolysis Department. Exposure in this group was considered to be mostly to the water-soluble compounds, NiSO4 and NiCl2, but also to a lesser degree to water-insoluble nickel compounds such as nickel-copper oxides and sulphides. The arithmetic mean ± SD for nickel concentration in lung tissues expressed in gg–1 dry wt for the 39 workers was 150 ± 280. In the workers employed in the Roasting and Smelting Department, the average nickel concentration was 330 ± 380; for those who worked in the Electrolysis Department it was 34 ± 48. Lung tissue from 16 autopsied persons not connected with the refinery had an average nickel concentration of 0.76 ± 0.39. Statistical analysis based on log-normal distributions of the measured nickel concentrations allowed three major conclusions to be formulated: (1) nickel refinery workers exhibit elevated nickel levels in lung tissues at autopsy; (2) workers of the Electrolysis Department and the Roasting Smelting Department constitute distinct groups with respect to the accumulation of nickel in lung tissue; (3) workers who were diagnosed to have lung cancer had the same lung nickel concentrations at autopsy as those who died of other causes. 相似文献
43.
Physical loading and performance as predictors of back pain in healthy adults A 5-year prospective study 总被引:4,自引:0,他引:4
Urho M. Kujala Simo Taimela Tero Viljanen Helena Jutila Jukka T. Vitasalo Tapio Videman Michele C. Battié 《European journal of applied physiology》1996,73(5):452-458
We investigated muscle strength, aerobic power, and occupational and leisure-time physical loading as predictors of back pain in a 5-year follow-up study. A cohort of 456 adults aged 25, 35, 45 and 55 years, free of back pain, participated in measurements of anthropometric characteristics, aerobic power and muscle strength characteristics at baseline. The subjects' levels and types of physical activity and occupational physical loading were also determined. At 5 years after the baseline examinations 356 of these subjects (78.1 %) were reached by mail, and 262 of them (73.6%) properly completed and returned a questionnaire including a detailed back pain history for the 5 years following the baseline measurements. Of this number 56 subjects (21 %) who reported back pain ( > 30 on a scale from 0 to 100) and functional impairment during the 5-year follow-up composed the marked back pain group. Other subjects (n = 71, 27%) noting lesser symptoms were included in the mild back pain group; 135 subjects (52%) reported having had no back pain. The subjects with marked back pain were on average taller than the subjects without back pain, while no such difference was found in body mass. Heavy occupational musculoskeletal loading (P = 0.005) and high general occupational physical demands (P = 0.036) predicted future back pain. Leisuretime physical activity, aerobic power or muscle strength characteristics were not predictive of future back pain. 相似文献
44.
Health-related quality of life in relation to gender and age in couples planning IVF treatment 总被引:2,自引:0,他引:2
Fekkes M Buitendijk SE Verrips GH Braat DD Brewaeys AM Dolfing JG Kortman M Leerentveld RA Macklon NS 《Human reproduction (Oxford, England)》2003,18(7):1536-1543
BACKGROUND: Specific subgroups of people planning IVF might be at risk of having more psychological or health-related problems. Identification of subgroups at risk may better enable allocation of appropriate counselling. METHODS: A group of 425 men and 447 women planning to undergo IVF treatment filled out a questionnaire. Four domains of health-related quality of life were measured, namely perceived emotional, physical, cognitive and social functioning. RESULTS: Young men and women (aged 21-30 years) planning IVF had more short-term social and emotional problems than people of the same age group in the general population. No substantial differences were found in cognitive and physical functioning for all age groups of men nor women planning IVF compared with the general population. A high level of irrational parenthood cognitions substantially accounted for a less optimal score on all the different domains of quality of life. These cognitions ('needing a child in order to live a happy life') were especially prevalent among younger women. CONCLUSIONS: Patients with high levels of irrational parenthood cognitions are at risk of a less optimal quality of life. A short cognitive counselling therapy is advised for patients with high levels of these cognitions. 相似文献
45.
"重返社区技能训练"对精神分裂症康复的作用 总被引:24,自引:0,他引:24
目的 :探讨重返社区技能训练对缓解社区精神分裂症患者的精神症状和改善其社会功能方面的作用。方法 :将 5 0例非急性期的社区精神分裂症患者随机分为技能训练组 (以下简称训练组 ;2 5例 )和对照组 (2 5例 ,其中脱落 2例 )。对技能训练组进行技能训练共 4周 ,然后随访 12周。采用阳性症状与阴性症状量表 (PANSS)、MorningSide康复状态量表 (MRSS)对患者进行评估。结果 :训练组患者的PANSS评分(3 9 96± 7 44 )、阴性量表总分 (11 92± 5 13 )、一般精神病理量表总分 (2 0 60± 2 95 )优于对照组 (分别为45 77± 8 95、 15 13± 4 79、 2 3 5 0± 5 3 7,P <0 0 5 ) ;训练组患者的MRSS总分 (3 1 60± 17 3 7)、依赖量表总分 (7 2 8± 5 41)、活动能力缺乏量表总分 (9 0 8± 5 5 2 )均优于对照组 (分别为 44 68± 13 61、 11 77± 5 17、15 0 0± 4 48) ;训练组的复发率 (4 % )低于对照组 (17% ) ,但差异无显著性。结论 :在药物治疗的基础上 ,重返社区技能训练能改善精神分裂症患者的症状及其社会功能 相似文献
46.
OBJECTIVE: To examine, using direct observation methodology, differences in family functioning at mealtime between families of school-age children with cystic fibrosis (CF) and families of school-age children without a chronic illness. METHOD: Family functioning was rated using the McMaster Mealtime Interaction Coding System (MICS) during a videotaped dinner among 28 families of children with CF and 27 families of non-ill, age-matched peers. Families were rated on overall family functioning and on six dimensions of the MICS: task accomplishment, communication, affect management, interpersonal involvement, behavior control, and role allocation. RESULTS: Ratings for families of a child with CF were significantly lower than they were for comparison families on overall family functioning and on four of the six MICS dimensions: communication, affect management, interpersonal involvement, and behavioral control. Moreover, a significantly greater percentage of families of children with CF were rated in the unhealthy range on overall family functioning and on five of six MICS dimensions. There was no relationship between family functioning and child weight status for children with CF. CONCLUSIONS: The current study suggests that for families of school-age children with CF, the family system is negatively affected during mealtime. Dietary interventions need to address family-centered, as well as child-centered, interventions to help families manage challenges presented during the family meal. 相似文献
47.
Comprehensive Assessment of Pain in Juvenile Rheumatoid Arthritis: An Empirical Model 总被引:1,自引:0,他引:1
Thompson Karen L.; Varni James W.; Hanson Virgil 《Journal of pediatric psychology》1987,12(2):241-255
A comprehensive assessment model of variables hypothesized toinfluence pediatric pain perception was empirically investigatedin 23 families who had a child with juvenile rheumatoid arthritis.To determine the effects of family environment, child psychologicaladjustment, and disease parameters on child pain perception,a developmentally appropriate model was developed. Childrenbetween the ages of 5 and 15 were found to be reliable judgesof their pain intensity. Several family environmental and childpsychological factors were found to interact with specific diseaseparameters in determining pediatric pain perception and report.A multidimensional age-appropriate assessment model is suggestedfor use in the further examination of pediatric chronic andrecurrent pain. 相似文献
48.
P. Lövsund P. Å. Öberg S. E. G. Nilsson T. Reuter 《Medical & biological engineering & computing》1980,18(3):326-334
Low-frequency and transient magnetic fields of moderate flux densities are known to generate visual phenomena, so-called magnetophosphenes.
In the present study, time-variable very low frequency (10–50 Hz) electromagnetic fields of moderate flux density (0–40 mT)
were used to induce magnetophosphenes. The threshold values for these phosphenes were determined as a function of the frequency
of the magnetic field both in normal subjects and colour defective ones. Maximum sensitivity occurred at a frequency of approximately
20–30 Hz, and with broad-spectrum light the threshold flux density was 10–12 mT. The threshola values were found to be dependent
upon the intensity and the spectral distribution of the background light. Sensitivity decreased during dark adaptation. In
certain respects deutans differed from subjects with normal colour vision. Possible mechanisms for generation of magnetophosphenes
are discussed. The present magnetic threshold curves show a close resemblance to corresponding curves obtained by electric
stimulation at various frequencies provided the electric thresholds are divided by the a.c. frequency. These problems are
under current investigation in our laboratory. This is in full agreement with the assumption that the fluctuating magnetic
field affects retinal neurons by inducing currents which polarise synaptic terminals. 相似文献
49.
奎的平和氯丙嗪对精神分裂症认知功能影响的双盲对照研究 总被引:2,自引:0,他引:2
目的 :探讨奎的平和氯丙嗪对精神分裂症患者认知功能的影响。方法 :40例精神分裂症患者随机均分为奎的平组和氯丙嗪组 ,在治疗前、治疗后 4、 6周作知识、算术、数字符号、数字广度 (顺、逆 )、木块拼图、瞬时逻辑记忆、视觉再生即刻和延迟、STROOPC测验、词汇流畅、TOH总分 ,计划时间、延迟逻辑记忆、WCST等神经心理测验 ,整个研究过程采用双盲双模拟法。为观察学习效应 ,12例健康者在相同间隔时间作神经心理测验。所得数据用SPSS10 0进行统计分析。结果 :治疗后 ,奎的平组大部分患者神经心理测验成绩提高而氯丙嗪组的测验结果变化不大 ,尤其在注意、执行功能方面。奎的平对精神分裂症患者认知功能的改善作用优于氯丙嗪 (P <0 0 5 )。结论 :奎的平对精神分裂症患者的注意和执行功能有改善作用而氯丙嗪不明显。 相似文献
50.
M. Cikrt J. Hurych D. Kuklová J. Havrdová P. Lepší J. Kopecký B. Milek A. Nauš 《International archives of occupational and environmental health》1985,55(3):241-246
Summary In a 61-year-old woman, who had been exposed for 20 years to cadmium in the production of Ni-Cd batteries, nephrectomy of the contracted kidney was performed. The removed kidney was examined histologically and the cadmium concentration was determined in the cortex (44.97 g g–1) and in the medulla (7.71 g g–1). The homogenates of the renal cortex and medulla were subjected to gel filtration on Sephadex G-75. In the cortex, as well as the medulla, cadmium was predominantly found in the low-molecular (metallothionein) fraction, but in the cortex, Cd content in this fraction was six times higher than in the medulla. The determination of SH groups and proteins in high- and low-molecular fractions indicates an induction of the metallothionein formation primarily in the renal cortex. 相似文献