首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   13874篇
  免费   1043篇
  国内免费   241篇
耳鼻咽喉   102篇
儿科学   239篇
妇产科学   136篇
基础医学   1477篇
口腔科学   384篇
临床医学   1527篇
内科学   2303篇
皮肤病学   423篇
神经病学   1012篇
特种医学   404篇
外国民族医学   2篇
外科学   931篇
综合类   1696篇
现状与发展   3篇
一般理论   1篇
预防医学   1218篇
眼科学   1136篇
药学   1314篇
  4篇
中国医学   223篇
肿瘤学   623篇
  2024年   27篇
  2023年   191篇
  2022年   400篇
  2021年   514篇
  2020年   480篇
  2019年   443篇
  2018年   426篇
  2017年   447篇
  2016年   456篇
  2015年   494篇
  2014年   853篇
  2013年   993篇
  2012年   822篇
  2011年   876篇
  2010年   705篇
  2009年   673篇
  2008年   735篇
  2007年   690篇
  2006年   575篇
  2005年   500篇
  2004年   461篇
  2003年   363篇
  2002年   303篇
  2001年   282篇
  2000年   220篇
  1999年   206篇
  1998年   193篇
  1997年   161篇
  1996年   132篇
  1995年   123篇
  1994年   109篇
  1993年   109篇
  1992年   99篇
  1991年   82篇
  1990年   78篇
  1989年   79篇
  1988年   77篇
  1987年   70篇
  1986年   76篇
  1985年   116篇
  1984年   107篇
  1983年   69篇
  1982年   68篇
  1981年   64篇
  1980年   49篇
  1979年   45篇
  1978年   35篇
  1977年   23篇
  1976年   14篇
  1975年   22篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
11.
Objective: Despite its negative effects, smoking is more common among individuals with asthma compared to those without. Anxiety sensitivity (fear of arousal-related sensations) is associated with both smoking and asthma; however, no research, to date, has examined the interplay between these three factors. Thus, the purpose of the current study was to evaluate the mediating role of anxiety sensitivity in the association between asthma diagnosis and smoking status. Methods: The current study was a secondary analysis of data from three existing datasets of non-smokers and smokers with and without asthma (n?=?433; 56.3% female, Mage?=?34.01 years, SD?=?13.9). Participants provided information on their asthma diagnosis status and smoking status and completed self-report measures. Results: As hypothesized, after controlling for gender, race and age, there was a significant indirect effect of asthma diagnosis on smoking status through anxiety sensitivity (95% CI?=?0.07–0.48). Conclusions: These results indicate that the association between asthma diagnosis and smoking status appears to be driven, in part, by anxiety sensitivity and suggest that anxiety sensitivity may serve as an important target for prevention and intervention efforts for smokers with asthma.  相似文献   
12.
《The Journal of arthroplasty》2022,37(9):1793-1798
BackgroundDespite numerous advances in the implant design and surgical technique, improvement in patient satisfaction following total knee arthroplasty (TKA) has plateaued. Various TKA alignment strategies have been introduced that impact the coronal positioning of the tibial component relative to the native joint line. This study aims to analyze if postoperative variance of the joint line from preoperative native alignment is correlated with changes in patient-reported outcomes following primary TKA.MethodsA retrospective review of an academic center’s patient population identified all primary TKAs between 2013 and 2021 with full-length, standing radiographs and patient-reported outcome measures (PROMs) data. These measures included the Knee injury and Osteoarthritis Outcome Score for Joint Replacement, Patient-Reported Outcome Measurement Information System, and Veterans RAND 12 scores. Preoperative and postoperative radiographic measurements for hip-knee angle, tibia-metaphyseal angle, tibial-axis orientation angle, and joint-line obliquity angle were recorded. Three-month, 1-year, and 2-year PROM scores were correlated with the change in degrees for each of the angles using a Spearman’s correlation. A Mann-Whitney U-test was used to compare angular changes with a change in PROM scores.ResultsOne hundred and ninety nine patients (204 knees) with a mean age of 67 years were included. Average follow-up was 23 months. Three-month, 1-year, and 2-year follow-up rates were 93%, 64%, and 34%, respectively. Improvements were seen across all PROMs regardless of an angular change.ConclusionThere were no clear correlations between PROMs and variation in joint line obliquity in the coronal plane. These data suggest that the magnitude of the variation in coronal tibial alignment from native alignment does not impact PROMs. Further study is indicated to correlate an angular change with functional measures.  相似文献   
13.
14.
A new strategy to yield information from the maximum number of voxels, each at the optimum signal-to-noise ratio (SNR) per unit time, in MR spectroscopic imaging (MRSI) is introduced. In the past, maximum acquisition duty-cycle was obtained by multiplexing in time several single slices each repetition time (TR), while optimal SNR was achieved by encoding the entire volume of interest (VOI) each TR. We show that optimal SNR and acquisition efficiency can both be achieved simultaneously by multiplexing in space and time several slabs of several slices, each. Since coverage of common VOIs in 3D proton MRSI in the human brain typically requires eight or more slices, at 3 T or higher magnetic fields, two or more slabs can fit into the optimum TR (approximately 1.6 s). Since typically four or less slices would then fit into each slab, Hadamard encoding is favored in that direction for slice profile reasons. It is demonstrated that per fixed examination length, the new method gives, at 3 T, twice as many voxels, each of the same SNR and size, compared with current 3D chemical shift imaging techniques. It is shown that this gain will increase for more extensive spatial coverage or higher fields.  相似文献   
15.
BACKGROUND: A low level of response to alcohol has been associated with both the genetic constitution of the regulatory region (SLC6A4) of the human serotonin (5-hydroxytryptamine, 5-HT) transporter (5-HTT) and with future alcohol intake and an increased risk for alcoholism. To date, all studies of relevant polymorphisms have been carried out in populations in the United States. METHODS: Data were extracted from a subset (n = 243) of a cohort of children who have been observed since birth through evaluation of the family history of alcoholism and psychosocial risk influences. At age 16 years, the response to alcohol was assessed with the Self-Rating of the Effects of Alcohol (SRE) questionnaire, and the average amount of alcohol intake per month was assessed during the prior 6 months. Additional variables that were measured included the 5-HTT genotype, externalizing behavior, and sociodemographic variables, such as gender and age. RESULTS: The level of response to alcohol was significantly lower among carriers of two long alleles of the 5-HTT regulatory region compared with carriers of one or two short alleles (Mann-Whitney U = 5225.0, p = .005). In a multiple regression analysis, the level of response to alcohol and externalizing behavior but not psychosocial factors significantly predicted the average amount of alcohol intake per month. CONCLUSIONS: This study demonstrates that, independent of the assessed psychosocial variables, the 5-HTT genotype correlated with the level of response to alcohol and predicted alcohol intake among 16-year-old adolescents.  相似文献   
16.
目的探讨胎儿生长迟缓(FGR)与新生儿胰岛素敏感性变化的关系。 方法昆明医学院第一附属医院于2004年4~12月,对72例小于胎龄儿(SGA)和48例适于胎龄儿(AGA)空腹血糖(FPG)、空腹胰岛素(FINS)、C 肽、HDL C、LDL C、TG、非酯化脂肪酸(NEFA)等指标,计算葡萄糖/胰岛素比值(G/I)、胰岛素敏感性指数(ISI)、胰岛素抵抗指数(HOMA IR)、胰岛β细胞功能(HBCI)等,探讨FGR与新生儿胰岛素敏感性变化的关系。 结果(1)SGA组FPG、HDL C低于AGA组,而FINS、LDL C、TG、NEFA高于AGA组(P<001);(2)SGA组G/I比值、ISI低于AGA组,HOMA IR高于AGA组(P<001),而HBCI两组相比差异无显著性(P>005)。 结论FGR儿在生命早期存在胰岛素敏感性降低和不同程度的胰岛素抵抗(IR),而胰岛β细胞功能无明显变化。  相似文献   
17.
The trigone sensitivity test, a complementary test to cystometry, has been proposed as a method for distinguishing certain clinical disorders. Pressure is applied to the trigone region of the bladder by pulling upon a Foley catheter with the balloon inflated and the amount of force needed to induce an urge to void is recorded. Although the trigone sensitivity test has been proposed as a test of exteroceptive function, it is possible that deeper receptors, perhaps proprioceptors, are actually responsible for the awareness of the urge to void during the study. The present investigation compared the trigone sensitivity test with provoked detrusor contraction in 107 patients. The findings indicate that variations in the two responses occur independently of each other. It is concluded that different neural pathways are responsible for the two functions. The hypothesis that exteroceptive and not proprioceptive nerves are being measured during trigone sensitivity testing is supported by these findings.  相似文献   
18.
汤先镗  王文铨 《农垦医学》1989,11(3):141-146
在新疆石河子市远郊缺碘地甲病区7~17岁儿童中取样,检测智力、精神运动功能、身高、体重和骨龄,发现精神运动发育障碍和骨龄落后的程度及发生频度明显高于非病区;而智力落后和体格发育落后两区无显著差异。根据这一发现认为在“亚地克病”诊断中,“精神运动发育测验”较“比内测验”更具有特异性和敏感性;建议在“出生、居住于缺碘地甲病区”前提下,将精神运动发育障碍和智力落后并列为主要条件。另根据地克病的分型原则,提出“亚地克病”的分型标准。  相似文献   
19.
改善胰岛素敏感性对血压影响的相关研究   总被引:3,自引:0,他引:3  
目的 :观察胰岛素增敏剂二甲双胍改善 2型糖尿病胰岛素敏感性后对血压的影响。方法 :71例 2型糖尿病人口服二甲双胍 (格华止 ) 85 0 mg,qd-bid。治疗前后测定 BMI、血压、FBG、PBG、FINS、PINS,并按 HOMA模型计算胰岛素抵抗指数和胰岛素分泌指数。结果 :( 1)二甲双胍治疗 8周后 ,BMI治疗前后无显著性差异 ;血压治疗后明显下降 ,降压幅度达 ( 13.1± 4.97) /( 4 .2 2± 9.93) mm Hg,血压治疗前后有显著性差异。 ( 2 )治疗后 F BG、 PBG、 FINS均明显下降 ,治疗前后有显著性差异。 ( 3)治疗后 HOMA-IR下降 ,IAI升高 ,治疗前后有显著性差异 ,但 HOMA-IS、 FINS/FBG无显著性差异。结论 :二甲双胍治疗 2型糖尿病 ,在降低血糖、改善 IR的同时 ,伴有血压的明显下降  相似文献   
20.
脂肪抽吸术对胰岛素敏感性及脂质代谢的影响   总被引:2,自引:1,他引:1  
目的了解脂肪抽吸术对胰岛素抵抗与脂质代谢的影响,并探讨其临床意义。方法对20例接受腹部脂肪抽吸术者术前及术后2个月的血清三酰甘油、总胆固醇、高密度脂蛋白胆固醇、低密度脂蛋白胆固醇,胰岛素敏感性进行测量并进行比较。结果术后与脂肪抽吸术前比较,术后胰岛素敏感性增强(P〈0.01),血清总胆固醇与低密度脂蛋白胆固醇水平下降。结论腹部脂肪抽吸术在去除大量皮下脂肪的同时,对胰岛素抵抗、脂质代谢等心脑血管危险因素也有非常有益的影响。  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号