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   44897篇
  免费   4721篇
  国内免费   892篇
耳鼻咽喉   320篇
儿科学   921篇
妇产科学   577篇
基础医学   3477篇
口腔科学   1508篇
临床医学   4268篇
内科学   5734篇
皮肤病学   485篇
神经病学   3402篇
特种医学   1409篇
外国民族医学   3篇
外科学   3782篇
综合类   4997篇
现状与发展   5篇
一般理论   2篇
预防医学   7855篇
眼科学   583篇
药学   3475篇
  27篇
中国医学   4521篇
肿瘤学   3159篇
  2024年   156篇
  2023年   1012篇
  2022年   1494篇
  2021年   1853篇
  2020年   1870篇
  2019年   1809篇
  2018年   1794篇
  2017年   1709篇
  2016年   1578篇
  2015年   1380篇
  2014年   3282篇
  2013年   3283篇
  2012年   2639篇
  2011年   2809篇
  2010年   2139篇
  2009年   2057篇
  2008年   2315篇
  2007年   2356篇
  2006年   2098篇
  2005年   1766篇
  2004年   1450篇
  2003年   1378篇
  2002年   1072篇
  2001年   985篇
  2000年   798篇
  1999年   686篇
  1998年   502篇
  1997年   524篇
  1996年   405篇
  1995年   426篇
  1994年   385篇
  1993年   318篇
  1992年   314篇
  1991年   276篇
  1990年   221篇
  1989年   205篇
  1988年   202篇
  1987年   162篇
  1986年   130篇
  1985年   119篇
  1984年   106篇
  1983年   72篇
  1982年   71篇
  1981年   67篇
  1980年   61篇
  1979年   38篇
  1978年   35篇
  1977年   30篇
  1976年   19篇
  1975年   20篇
排序方式: 共有10000条查询结果,搜索用时 25 毫秒
31.
BackgroundNew antidiabetic agents (sodium-glucose cotransporter-2 inhibitor [SGLT2i] and glucagon-like peptide-1 receptor agonist [GLP-1RA]) and metabolic surgery have protective effects on metabolic syndromes.ObjectivesTo compare the changes of metabolic parameters and costs among patients with obesity and type 2 diabetes undergoing metabolic surgery and initiating new antidiabetic agents over 12 months.SettingHong Kong Hospital Authority database from 2006–2017.MethodsThis is a population-wide retrospective cohort study consisting of 2616 patients (1810 SGLT2i, 528 GLP-1RA, 278 metabolic surgery). Inverse probability treatment weighting of propensity score was applied to balance baseline covariates of patients with obesity and type 2 diabetes who underwent metabolic surgery, or initiated SGLT2i or GLP-1RA. Metabolic parameters and direct medical costs were measured and compared from baseline to 12 months in metabolic surgery, SGLT2i, and GLP-1RA groups.ResultsPatients in all 3 groups had improved metabolic parameters over a 12-month period. Patients with metabolic surgery achieved significantly better outcomes in BMI (?5.39, ?.56, ?.40 kg/m2, P < .001), % total weight loss (15.16%, 1.34%, 1.63%, P < .001), systolic (?2.21, ?.59, 1.28 mm Hg, P < .001) and diastolic (?1.16, .50, ?.13 mm Hg, P < .001) blood pressure, HbA1c (?1.80%, ?.77%, ?.80%, P < .001), triglycerides (?.64, ?.11, ?.09 mmol/L, P < .001), and estimated glomerular filtration rate (3.08, ?1.37, ?.41 mL/min/1.73m2, P < .001) after 12 months compared with patients with SGLT2i and GLP1-RA. Although the metabolic surgery group incurred the greatest direct medical costs (US$33,551, US$10,945, US$10,627, P < .001), largely due to the surgery itself and related hospitalization, the total monthly direct medical expenditure of metabolic surgery group became lower than that of SGLT2i and GLP-1RA groups at 7 months.ConclusionBeneficial weight loss and metabolic outcomes at 12 months were observed in all 3 groups, among which the metabolic surgery group showed the most remarkable effects but incurred the greatest medical costs. However, studies with a longer follow-up period are warranted to show long-term outcomes.  相似文献   
32.
33.
34.

Introduction

In the United States there has been a large increase in participation in lacrosse for both males and females. The purpose of this study was to analyze the number of head injuries, injury rates (calculated using the reported number of participants) and types of head injuries that are seen in emergency departments in the United States.

Methods

We compared injuries between male and female lacrosse participants. This was a retrospective study using a publicly available database produced by the US Consumer Product Safety Commission and information about lacrosse participation from US Lacrosse.

Results

A linear regression was performed and showed a positive correlation between number of head injuries to males and time from 2002 to 2010 (R2?=?0.823; p?=?0.001). While the number of injuries to the head in female lacrosse participants was not significant. There was a negative correlation between the number of head injuries to males from 2010 to 2016 (R2?=?0.800; p?=?0.007), but again, there was no significance for female injury count (R2?=?0.417; p?=?0.117). Other significant differences between head injuries in males and females included the mechanism of injury and the type of injury recorded.

Conclusion

The most recent data from 2010 to 2016, suggest that both males and females have had a decrease in injury rate. However the total number of female head injuries is not significantly decreasing and as the sport continues to grow there will likely be more total head injuries and visits to the emergency department.  相似文献   
35.
36.
目的: 探讨非活动性结核性胸膜炎与活动性结核性胸膜炎CT扫描影像表现。方法: 对2012年6月1日至2021年3月30日在首都医科大学附属北京胸科医院就诊的单纯非活动性结核性胸膜炎患者68例和同期活动性结核性胸膜炎44例的CT扫描影像表现进行比较。结果: (1) 68例非活动性结核性胸膜炎患者 CT扫描影像表现中胸膜粘连62例(91.2%),胸膜有钙化者28例(41.2%),叶间裂受累22例(32.4%),胸腔积液12例(17.6%),包裹性胸腔积液8例(11.8%)。(2)44例活动性结核性胸膜炎患者CT扫描影像表现中胸膜粘连30例(68.2%),未见胸膜钙化,叶间裂受累32例(72.7%),胸腔积液43例(97.7%),包裹性胸腔积液26例(59.1%)。(3)非活动性与活动性结核性胸膜炎CT扫描影像比较:胸膜粘连、胸膜钙化发生率高,差异均有统计学意义(χ2=9.630,P=0.002;χ2=23.737,P=0.000);叶间裂受累、胸腔积液、包裹性胸腔积液的发生率低,差异均有统计学意义(χ2=12.692,P=0.000;χ2=68.548,P=0.000;χ2=28.301,P=0.000)。结论: 非活动性结核性胸膜炎的CT扫描影像与活动性结核性胸膜炎比较胸膜粘连、胸膜钙化的发生率高,胸腔积液、包裹性胸腔积液、叶间裂受累的发生率低。识别非活动性和活动性结核性胸膜炎的CT扫描影像特点,对患者临床治疗有指导意义。  相似文献   
37.
完美主义与基督教信仰   总被引:2,自引:0,他引:2  
目的 考察个体的宗教信仰与完美主义心理之间的关系。方法 采用质的研究方法,对两位受访者(分别为功能障碍型完美主义与健康的完美主义)追行个案研究。结果 两名受访者的基督教(新教)信仰封其完关主义的负面倾向有所矫正,受访者的人际关系和自我认知因为宗教信仰而有所改善。结论 基督教(新教)信仰有利于修正受访者自体表象与权威客体表象的关系。在象征意义上,“上帝”的概念可以理解为“较好的”权威客体表象。  相似文献   
38.
启发式教学在生理学教学中的应用研究   总被引:5,自引:1,他引:4  
针对生理学课程理论抽象、实验操作复杂等特点,阐述了启发式教学方法取代传统填鸭式教学方法的必然性。因生理学教学难度大、实验操作条件高,故着重介绍了问答式、讨论式、演绎式、归纳式、直观式等五种启发式教学方法在生理学教学中的应用。  相似文献   
39.
目的比较2%强化戊二醛(下称戊二醛)气雾熏蒸法与浸泡消毒法消毒吸痰管的效果.方法消毒按5周期(1个周期12 d)进行,每周期将200根使用过的吸痰管经初步处理,即5% 84消毒液浸泡30 min后清水冲洗干净晾干.将每周期200根吸氮管随机均分为实验组和对照组,实验组采用戊二醛原液气雾熏蒸法消毒4 h,对照组采用戊二醛原液浸泡消毒30 min,12 d为1个周期.两组分别于第1、6、12天对消毒后的吸痰管及消毒过程中的戊二醛采样行细菌菌落数计数,并观察有无细菌生长.结果两组每周期第1、6天吸痰管和消毒液标本均未检测出细菌,且无致病微生物生长;每周期第12天对照组吸痰管和消毒液标本均检测出细菌,实验组未检测出细菌.结论气雾熏蒸法消毒灭菌效果可靠,具有节约开支、使用方便、有利于吸痰管的保存与放置等优点.  相似文献   
40.
AIMS: To establish all-cause and cause-specific death rates, and risk factors for mortality in insulin-treated diabetic individuals living in the province of Canterbury, New Zealand. METHODS: Insulin-treated diabetic subjects (n = 995) on the Canterbury Diabetes Registry were followed up over 15 years and vital status determined. Death rates were standardized and hazard regression was used to model the effects of demographic covariates on relative survival time. RESULTS: There were 419 deaths in 11 226.3 person-years of follow-up with a standardized mortality ratio (SMR) of 2.0 (95% confidence interval (CI) 1.8-2.2). Relative mortality was greatest for the group aged 0-29 years (SMR 3.0 (95% CI 2.4-3.7)). After controlling for diabetes duration and gender, a 10-year increment in age of onset was associated with a 33% decrease in relative hazard (95% CI 29-36%), indicating that excess mortality due to diabetes declines with rising age of onset. After controlling for age of onset and gender, each 10-year increment in duration of diabetes is associated with a 26% decrease in relative hazard (95% CI 24-29%), indicating that with longer survival the mortality hazard approaches the general population hazard. Relative mortalities were increased for cardiovascular, renal and respiratory disease, but not malignancy. Relative mortality from acute metabolic complications was increased in the subgroup with age of onset of diabetes < 30 years and requiring insulin within 1 year of diagnosis. CONCLUSIONS: Mortality rates are high for insulin-treated diabetic individuals relative to the general population.  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