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   88866篇
  免费   8880篇
  国内免费   556篇
耳鼻咽喉   259篇
儿科学   2038篇
妇产科学   1701篇
基础医学   5569篇
口腔科学   4390篇
临床医学   16478篇
内科学   7908篇
皮肤病学   680篇
神经病学   5270篇
特种医学   890篇
外科学   3477篇
综合类   8211篇
现状与发展   3篇
一般理论   102篇
预防医学   34826篇
眼科学   417篇
药学   3105篇
  80篇
中国医学   886篇
肿瘤学   2012篇
  2024年   276篇
  2023年   2702篇
  2022年   3561篇
  2021年   5005篇
  2020年   5051篇
  2019年   4876篇
  2018年   4240篇
  2017年   3944篇
  2016年   3754篇
  2015年   3701篇
  2014年   5842篇
  2013年   7693篇
  2012年   5044篇
  2011年   5539篇
  2010年   4108篇
  2009年   4222篇
  2008年   4133篇
  2007年   4171篇
  2006年   3551篇
  2005年   2744篇
  2004年   2374篇
  2003年   2040篇
  2002年   1519篇
  2001年   1469篇
  2000年   1265篇
  1999年   881篇
  1998年   748篇
  1997年   583篇
  1996年   490篇
  1995年   342篇
  1994年   318篇
  1993年   327篇
  1992年   262篇
  1991年   225篇
  1990年   182篇
  1989年   145篇
  1988年   173篇
  1987年   115篇
  1986年   101篇
  1985年   111篇
  1984年   78篇
  1983年   52篇
  1982年   46篇
  1981年   43篇
  1980年   51篇
  1979年   32篇
  1978年   36篇
  1977年   37篇
  1976年   33篇
  1975年   34篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
Background and aimsObesity and overweight in children are associated with an increased risk of several health issues. The present study aimed to assess the effects of a multi-disciplinary program (including nutrition education using a smartphone game, physical activity, and cognitive behavioral therapy [CBT]) on the management of obesity and overweight in elementary school girls.Methods and resultsSixty-two school girls above the 85th percentile of body mass index (BMI) for age were randomly assigned to two groups. During 10 weeks of study, the intervention group received a multi-disciplinary intervention, including nutrition education using a smartphone game, aerobic exercise, and CBT. The control group received usual traditional nutritional education. Biochemical and metabolic factors were assessed, including fasting blood sugar (FBS), lipid profile, serum leptin, and anthropometric measurements. The Dutch Eating Behavior Questionnaire (DEBQ) and metabolic equivalent test (MET) were also conducted. The intervention group showed more promising results in weight loss, waist circumference (WC), hip circumference (HC), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), triglyceride (TG), and FBS compared to the control group (P < 0.05). In addition, MET and DEBQ scores in all three sections of emotions, stimuli, and restriction were better in the intervention group than in the control group (P < 0.05). However, there was no significant difference between groups regarding the results of serum leptin and waist-to-hip ratio (WHR; p > 0.05).ConclusionsThe results indicated that education through smartphone games could possibly affect performance in real life. In addition, the multi-disciplinary approach to childhood obesity might have better performance in most areas than the single-intervention approach in obesity management.  相似文献   
82.
83.
《Indian heart journal》2022,74(5):414-419
BackgroundLeft ventricular outflow tract obstruction (LVOTO) is commonly observed in patients with hypertrophic cardiomyopathy (HCM) or left ventricular hypertrophy (LVH). Some patients develop LVOTO provoked by physical exertion, and hence termed dynamic LVOTO (DLVOTO). However, its precise prevalence and mechanism are still unclear.AimTwo-dimensional speckle tracking echocardiography (2D STE) seems to be helpful for the detection of early LV structural abnormalities. This study aimed to examine the possible role of segmental as well as global longitudinal strain in identifying DLVOTO non-HCM patients as detected by dobutamine stress echocardiography (DSE).Methods and resultsTwo hundred and fifty patients without structural heart disease had undergone conventional transthoracic echocardiography, 2D STE, and DSE. All patients with non-ischemic evidence were divided into two groups according to the DSE results; DLVOTO (+) and DLVOTO (?).Among 250 patients, 50 patients (36%) had shown DLVOTO after DSE (15 males, 35 females; mean age 55±7years). They were compared with 90 non -LVOTO obstruction patients (43 males, 47 females; mean age 57±6years). Based on multivariate logistic regression analysis, the independent predictors of provoked DLVOTO during DSE were resting basal septal longitudinal strain BS-LS average (p < 0.001), resting LA reservoir strain (p < 0.001), and systolic LVOT diameter (p = 0.03). Resting BS-LS average with cut-off - 17.5% was recognized as a critical indicator of DLVOTO, with sensitivity 78%, and specificity 95% (better than systolic LVOT diameter of sensitivity 76%, and specificity 15% and resting LA reservoir strain which showed poor AUC at ROC curve 0.007).ConclusionWe demonstrate that provoked LVOTO during DSE in non HCM symptomatic patients is directly correlated to resting regional LS, where the increased BS-LS of ≥ ?17.5% was a key determinant of LVOT gradient provocation. Assessment of baseline BS-LS average might be a bedside simple tool for detection of patients with DLVOTO not able to do DSE.  相似文献   
84.
Medical interactions around reproduction are increasingly extending beyond the physician's office and onto the Internet, where negotiation with medical authority occurs in complex and dynamic ways. Recently, scholars have noted the Internet's potential for creating spaces where women can dialogue with and reconstruct medical authority, yet this growing body of work is overwhelming heteronormative. This paper thus interrogates how lesbian women use the Internet to challenge, deploy, and rework medical authority around reproduction while navigating the transition to parenthood. I draw from 17 online journals authored by lesbian couples during the conception, pregnancy, and birth of their first child, each spanning between 18 months and 2 years, in order to understand how the transition process unfolds over time. I argue that lesbian couples engage with medical authority when seeking affirmation and normalisation yet discard and publicly reject the heteronormative assumptions that accompany reproductive medicine. Further, they chart a new process that I term ‘constructing queer mother‐knowledge’, in which they critique and balance knowledges from institutionalised medicine, their own bodies, and their queer communities. With this new concept, I complicate understandings of lesbian mothers‐to‐be and their interactions with medical authority as they build subversive families.  相似文献   
85.
86.
曾建国  杨子墨 《中国现代中药》2021,23(12):2031-2036
湖南省历经8年聚力打造“湘九味”中药材品牌,已逐渐形成品牌品种引领的产业链发展模式。为达成湖南省中药材产业链千亿发展目标,梳理了“湘九味”品牌培育历程,厘清并阐释了相关概念,分析了产业发展现状及问题,研判了大健康应用背景下未来的中药材产业的发展趋势,并提出相关发展建议。  相似文献   
87.
88.
89.
《Value in health》2022,25(12):1958-1966
ObjectivesNational health technology assessments (HTAs) across Europe show differences in evidentiary requirements from assessments by the European Medicines Agency (EMA), affecting time to patient access for drugs after marketing authorization. This article analyzes the differences between EMA and HTA bodies’ evidentiary requirements for oncology drugs and provides recommendations on potential further alignment to minimize and optimally manage the remaining differences.MethodsInterviews were performed with representatives and drug assessment experts from EMA and HTA bodies to identify evidentiary requirements for several subdomains and collect recommendations for potentially more efficiently addressing differences. A comparative analysis of acceptability of the evidence by EMA and the HTA bodies and for potential further alignment between both authorities was conducted.ResultsAcceptability of available evidence was higher for EMA than HTA bodies. HTA bodies and EMA were aligned on evidentiary requirements in most cases. The subdomains showing notable differences concerned the acceptance of limitation of the target population and extrapolation of target populations, progression-free survival and (other) surrogate endpoints as outcomes, cross-over designs, short trial duration, and clinical relevance of the effect size. Recommendations for reducing or optimally managing differences included joint early dialogues, joint relative effectiveness assessments, and the use of managed entry agreements.ConclusionsDifferences between assessments of EMA and HTA bodies were identified in important areas of evidentiary requirements. Increased alignment between EMA and HTA bodies is suggested and recommendations for realization are discussed.  相似文献   
90.
This study aimed at deriving occupational thresholds of toxicological concern for inhalation exposure to systemically-acting organic chemicals using predicted internal doses. The latter were also used to evaluate the quantitative relationship between occupational exposure limit and internal dose. Three internal dose measures were identified for investigation: (i) the daily area under the venous blood concentration vs. time curve, (ii) the daily rate of the amount of parent chemical metabolized, and (iii) the maximum venous blood concentration at the end of an 8-hr work shift. A dataset of 276 organic chemicals with 8-hr threshold limit values-time-weighted average was compiled along with their molecular structure and Cramer classes (Class I: low toxicity, Class II: intermediate toxicity, Class III: suggestive of significant toxicity). Using a human physiologically-based pharmacokinetic model, the three identified dose metrics were predicted for an 8-hr occupational inhalation exposure to the threshold limit value for each chemical. Distributional analyses of the predicted dose metrics were performed to identify the percentile values corresponding to the occupational thresholds of toxicological concern. Also, simple linear regression analyses were performed to evaluate the relationship between the 8-hr threshold limit value and each of the predicted dose metrics, respectively. No threshold of toxicological concern could be derived for class II due to few chemicals. Based on the daily rate of the amount of parent chemical metabolized, the proposed internal dose-based occupational thresholds of toxicological concern were 5.61?×?10?2 and 9?×?10?4 mmol/d at the 10th percentile level for classes I and III, respectively, while they were 4.55?×?10?1 and 8.5?×?10?3 mmol/d at the 25th percentile level. Even though high and significant correlations were observed between the 8-hr threshold limit values and the predicted dose metrics, the one with the rate of the amount of chemical metabolized was remarkable regardless of the Cramer class (r2 = 0.81; n = 276). The proposed internal dose-based occupational thresholds of toxicological concern are potentially useful for screening-level assessments as well as prioritization within an integrated occupational risk assessment framework.  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