全文获取类型
收费全文 | 32064篇 |
免费 | 2619篇 |
国内免费 | 737篇 |
专业分类
耳鼻咽喉 | 82篇 |
儿科学 | 380篇 |
妇产科学 | 283篇 |
基础医学 | 1295篇 |
口腔科学 | 359篇 |
临床医学 | 2377篇 |
内科学 | 4817篇 |
皮肤病学 | 284篇 |
神经病学 | 1918篇 |
特种医学 | 322篇 |
外国民族医学 | 1篇 |
外科学 | 843篇 |
综合类 | 3813篇 |
现状与发展 | 3篇 |
一般理论 | 4篇 |
预防医学 | 3826篇 |
眼科学 | 390篇 |
药学 | 12331篇 |
13篇 | |
中国医学 | 1032篇 |
肿瘤学 | 1047篇 |
出版年
2024年 | 70篇 |
2023年 | 557篇 |
2022年 | 783篇 |
2021年 | 1227篇 |
2020年 | 1127篇 |
2019年 | 1302篇 |
2018年 | 1352篇 |
2017年 | 1449篇 |
2016年 | 1251篇 |
2015年 | 1159篇 |
2014年 | 2164篇 |
2013年 | 4468篇 |
2012年 | 1916篇 |
2011年 | 1974篇 |
2010年 | 1677篇 |
2009年 | 1387篇 |
2008年 | 1326篇 |
2007年 | 1291篇 |
2006年 | 1141篇 |
2005年 | 1054篇 |
2004年 | 851篇 |
2003年 | 733篇 |
2002年 | 615篇 |
2001年 | 590篇 |
2000年 | 519篇 |
1999年 | 405篇 |
1998年 | 356篇 |
1997年 | 318篇 |
1996年 | 255篇 |
1995年 | 236篇 |
1994年 | 204篇 |
1993年 | 210篇 |
1992年 | 211篇 |
1991年 | 227篇 |
1990年 | 144篇 |
1989年 | 104篇 |
1988年 | 107篇 |
1987年 | 85篇 |
1986年 | 76篇 |
1985年 | 114篇 |
1984年 | 82篇 |
1983年 | 46篇 |
1982年 | 54篇 |
1981年 | 46篇 |
1980年 | 44篇 |
1979年 | 25篇 |
1978年 | 20篇 |
1977年 | 20篇 |
1976年 | 14篇 |
1974年 | 15篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
A set of calibrated lickometers provides continuous, quantitative monitoring of fluid consumption. It has been used in our laboratory at four levels of temporal resolution: 24 hr, 1 hr, 6 min, and for counting of individual licks. Convenient features are mounting of the licking tube-bottle assembly on the cage top (which permits the use of disposable plastic cages with litter) and automated collection of data with microcomputers. 相似文献
62.
A/J and C57BL/6J mice behave differently in tests for alcohol preference, open-field activity, defecation in the open field, cricket attacking, and rope climbing. Chimeric mice, i.e., mice containing both A/J cells and C57BL/6J cells, were constructed and tested for these behaviors. Patterns of behavior among A/JC57BL/6J chimeras are such as to suggest that none of these behavior differences is controlled by a single cell or clone and that the same cell population that gives rise to the strain difference in alcohol preference also gives rise to the differences in open-field activity and defecation, while separate cell populations control cricket killing and rope climbing.This research was supported by Research Grants AA 00388 and HD 03015 to M. N. N. and MH 18996 to K. B. Computing assistance was obtained from the Health Sciences Computing Facility, UCLA, supported by NIH Special Research Resources Grant RR-3. 相似文献
63.
苯丙胺类兴奋剂(ATS)娱乐性使用情况及其人群特征 总被引:7,自引:0,他引:7
目的 :了解娱乐性ATS使用者的人口学特征 ,使用方式及其他有关问题。方法 :采用病例发现法和易接近对象晤谈法 ,并结合滚雪球的方法 ,以问卷方式收集娱乐性ATS使用者的有关资料。结果 :娱乐性ATS使用者平均年龄 2 3 97± 4 95岁。未婚占 6 4 4 % ,同居占 1 5 3% ,离婚占 8 5%。高中及以上文化者占 84 7%。职业以服务员、个体商人和性工作者居多。摇头丸是最主要的滥用药物。约 90 %的人使用次数少于 50次。口服是最主要的服用途径。平均每次服用剂量约为 2 50mg ,多在周末服用 ( 72 9% )。获得ATS的主要来源是从朋友和熟人处购买 ( 72 9% )。使用ATS的主要目的包括 :提高情绪使自己快乐 ,使自己压抑时感到舒服些 ,帮助放松 ,帮助解除抑制 (情绪、行为、思维 )等。娱乐性ATS使用者合并使用酒精 ,海洛因 ,苯二氮 艹卓 类 ,大麻 ,致幻剂的比例分别为 81 3% ,2 2 0 % ,1 1 9% ,1 0 2 % ,1 7%。 96 %的ATS使用者的主要社交人群中有人使用ATS。 4 5 8%和 33 8%的使用者有临时性伴侣和性交易史。结论 :娱乐性ATS使用者为一特殊人群 ,应针对其特殊性制定相应的干预措施。 相似文献
64.
Preparation of Aminated Macroporous Polyvinyl Alcohol Resins and Evaluation for Bilirubin Adsorption
WANG Wei-chao ZHANG Sheng-nan HU Yue-han XIE Hui OU Lai-liang YU Yao-ting KONG De-ling GU Han-qing 《中国生物医学工程学报(英文版)》2008,17(3)
In the present study we prepared macroporous polyvinyl alcohol beads. A series of bilirubin adsorbents were generated by immobilization of eight amine agents to the beads as ligands. The adsorption of bilirubin was evaluated by in vitro static and dynamic adsorption tests. The results show that these adsorbents have excellent adsorption efficiency and capacity. Among the eight ligands, trimethylamine (TMA), triethylamine (TEA) and 1,6- hexanediamine(HDA) showed the highest adsorption capacity. The adsorption equilibrium can be achieved in half an hour, and the adsorption percentage of bilirubin was up to 80%. Static electricity and hydrophobic interaction played the main role in bilirubin adsorption, and the adsorption was found to match the monolayer model. The excellent adsorption of these adsorbents indicates their potential in clinical treatment. 相似文献
65.
Bergmo TS Kummervold PE Gammon D Dahl LB 《International journal of medical informatics》2005,74(9):705-710
BACKGROUND AND AIM: Electronic patient-provider communication promises to improve efficiency and effectiveness of clinical care. This study aims to explore whether a secure web-based messaging system is an effective way of providing patient care in general practices. METHOD: We conducted a randomised controlled trail and recruited 200 patients from the waiting area in one primary clinic in Norway. Participants were randomised to either the intervention group, which received access to a secure messaging system, or the control group receiving standard care without such access. Primary outcome measures were number of online consultations, telephone consultations and office visits in the two groups. Data were derived from patient records and collected 1 year prior to (baseline), and 1 year after the intervention. RESULTS: Forty-six percent of the patients who were given access to the messaging system (n=99) used the online communication system on at least one occasion (ranging from 1 to 17 messages per patient per year). A total of 147 electronic messages were sent to six general practitioners during a 1-year trial period. Eleven percent of the messages were to schedule an appointment. In 10% of the messages, the GP was unable to respond adequately and recommended an office visit. The reduction in office visits over time was greater for the intervention group than for the control group (P=0.034). There was however no significant difference in the number of telephone consultations between the groups during the study (P=0.258). CONCLUSION: The use of a secure electronic messaging system reduced the number of office visits at the general practice, but not phone consultations. 相似文献
66.
In a laboratory study of psychomotor sensitivity to alcohol, twins were asked “Would you drive a car now?” at 1, 2, and 3 h after drinking a standard dose of ethanol (0.75 g/kg). Correlations among these binary items, the Eysenck personality scales, and age were investigated using PRELIS and LISREL. Willingness to drive and Extraversion correlate at all three times in both males and females. In males, willingness to drive also correlates with Psychoticism, and in females it correlates negatively with the Lie (or Social Desirability) scale. Most correlations between cotwins in willingness to drive were significant in both monozygotic (MZ) and dizygotic (DZ) male twins but correlations were lower in female twins. Factor and Markovian models were fitted. In males there seem to be both genetic and cultural influences on willingness to drive when drunk. About half the genetic variance seems to be the pleiotropic effects of genes influencing Extraversion. The correlationswith Psychoticism, on the other hand, seem to be largely environmental in origin. The small sample size and lack of proper significance tests mean that these results must be interpreted with caution. 相似文献
67.
A. Gonzalez-Quintela M. Garrido F. Gude J. Campos A. Linneberg S. Lojo C. Vidal 《Clinical and experimental allergy》2008,38(1):152-160
Background Alcohol consumption is associated with increased serum IgE of unknown specificity. Objective To investigate the prevalence of specific IgE to cross‐reactive carbohydrate determinants (CCDs) in adults, and its relation to alcohol consumption. Methods Population‐based survey of 457 adults (218 abstainers, 195 light‐to‐moderate drinkers, 44 heavy drinkers). Specific IgE determinations included a CCD (MUXF3, the N‐glycan of bromelain), pollens (Lolium perenne and Olea europaea), Hymenoptera venoms (Apis mellifera and Vespula spp.), and a mite (Dermatophagoides pteronyssinus). We replicated these studies in an additional sample of alcoholics (n=138). Inhibition assays were performed in selected cases. Results In the general population, 5.6% of individuals (95% confidence interval 3.5–7.6%) showed positive (0.35 kU/L) CCD‐specific IgE. The levels of CCD‐specific IgE were particularly high in heavy drinkers, who also showed a high prevalence of positive IgE to pollens and Hymenoptera venoms, doubling (at least) the prevalence found in alcohol abstainers and light‐to‐moderate drinkers. The presence of IgE to pollens and Hymenoptera venoms was closely correlated with the presence of CCD‐specific IgE. These features were confirmed in the additional sample of alcoholics. Inhibition studies indicated a role of CCD interference in IgE positivity to pollen and Hymenoptera allergens in alcoholics. Conclusions CCD‐specific IgE is prevalent in heavy drinkers, and is associated with positive IgE to pollens and Hymenoptera venoms. Specific IgE results should be interpreted with caution in heavy drinkers. 相似文献
68.
Naomi Breslau 《Behavior genetics》1995,25(2):95-101
Recent epidemiologic studies have revealed that comorbidity of psychiatric disorders is far more pervasive than previously suspected. Strong associations have been reported between specific substance use disorders and between any mental disorder and any substance use disorder. This report focuses on comorbidity of nicotine dependence, a substance use disorder on which little epidemiologic information is available. Data come from an epidemiologic study of approximately 1000 young adults in southeast Michigan, in which the NIMH-DIS, revised according to DSM-III-R, was used. Lifetime prevalence of nicotine dependence was 20%. Males and females with nicotine dependence had increased odds for alcohol and illicit drug disorders, major depression, and anxiety disorders, compared with nondependent smokers and nonsmokers combined. Major depression and any anxiety disorder were associated specifically with nicotine dependence. Increased odds for alcohol or illicit drug disorders were observed also in nondependent smokers, compared to nonsmokers. History of early conduct problems increased the odds for nicotine dependence among smokers. Potential mechanisms in the comorbidity of nicotine dependence are discussed. 相似文献
69.
湖南省两地区成瘾物质使用状况调查报告:使用率及相关因素 总被引:12,自引:1,他引:12
本文采用整群抽样的方法,对湖南两地区城乡共2377人(15岁以上)的成瘾物质使用状况进行调查,其中男1179(49.6%)人,女1199(50.4%人),平均年龄男女分别为41.2(SD=17.5)和43.4(SD=18.6)。结果表明,饮酒率男性为57.5%,女性为17.3%,吸烟率男女分别为68.2%和11.7%;饮酒者多集中在每月饮1次左右的人群中(男57.9%,女77.9%),但吸烟者多集中在每日吸20支及以上(男52.4%,女42.9%)的人群中。除解热镇痛剂外,男性各种精神活性物质的使用频率及剂量皆男高于女性,开始使用的年龄及成瘾的年龄男性低于女性;性别、使用频度、最早使用的年龄、婚姻与饮酒、吸烟量关系最为密切。有14人使用过鸦片类物质,4人使用过兴奋剂。作者讨论了我国成瘾物质使用的特点,指出经济水平、社会文化背景等因素与我国社会性成瘾物质的使用有密切关系。 相似文献
70.
The advent of SAL (suction-assisted lipectomy) has dramatically increased the number of obese patients coming to our consultation offices. Despite several articles suggesting a conservative approach to fat suction, some reports insinuate that SAL might be a useful tool for obesity treatment. This hypothesis is refuted by a vast body of evidence that concludes that the adipose tissue may regenerate in adult humans. Therefore, surgical procedures are not advised as the method of choice to manage the disease. On the other hand, the terms obesity and being overweight may not be interchangeable. Obesity may be a disease whereas being overweight is asign of the disease. Consequently, proper preoperative selection of candidates for SAL becomes mandatory. The hCG (human chorionic gonadotropin) method for obesity treatment appears to be a complete program for the management of obesity. It contains pharmacologic, dietetic, and behavior modification aspects in a 40-day course of treatment. Some data suggest hCG to be lipolytic, thus explaining former clinical observations regarding body fat redistribution in treated patients. hCG commercial preparations contain -endorphin, an opioid peptide linked to mood behavior. This article speculates on the possible actions of the complex hCG -endorphin in the neuromodulation of mood and energy metabolism. The method comprises a behavior modification that helps in handling the patient better. There are some correlations between a current behavior modification program and the basic guidelines contained in the hCG protocol. Thus, the hCG method appears to be a reasonable alternative in the management of a long-standing, unsolved problem of human metabolism. 相似文献