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   15550篇
  免费   1296篇
  国内免费   1098篇
耳鼻咽喉   280篇
儿科学   191篇
妇产科学   257篇
基础医学   1491篇
口腔科学   541篇
临床医学   2484篇
内科学   1556篇
皮肤病学   96篇
神经病学   963篇
特种医学   473篇
外国民族医学   20篇
外科学   1316篇
综合类   3353篇
现状与发展   2篇
预防医学   1215篇
眼科学   647篇
药学   1641篇
  10篇
中国医学   473篇
肿瘤学   935篇
  2024年   24篇
  2023年   473篇
  2022年   777篇
  2021年   917篇
  2020年   937篇
  2019年   557篇
  2018年   509篇
  2017年   454篇
  2016年   498篇
  2015年   695篇
  2014年   1283篇
  2013年   1155篇
  2012年   1584篇
  2011年   1658篇
  2010年   1224篇
  2009年   809篇
  2008年   869篇
  2007年   914篇
  2006年   586篇
  2005年   332篇
  2004年   264篇
  2003年   308篇
  2002年   312篇
  2001年   273篇
  2000年   159篇
  1999年   109篇
  1998年   84篇
  1997年   77篇
  1996年   82篇
  1995年   4篇
  1994年   6篇
  1993年   1篇
  1992年   2篇
  1991年   1篇
  1990年   1篇
  1989年   4篇
  1987年   1篇
  1984年   1篇
排序方式: 共有10000条查询结果,搜索用时 343 毫秒
1.
Background and aimsWe intended to investigate the predictors for bowel resection in infants with necrotizing enterocolitis (NEC). We further developed a scoring system for better predicting bowel resection.MethodsA total of 207 infants who underwent surgical management at Children's Hospital, Chongqing Medical University between April 2008 and December 2020 were identified for the following investigation. Bowel resection was reviewed among the infants who underwent the procedure. Potential parameters related to bowel resection were explored using a multiple logistic regression method, and then a scoring system was developed.ResultsAmong the 207 patients who underwent operative intervention that were reviewed, 109 infants underwent bowel resection. Multivariate logistic regression analysis showed that birth weight, hypotension, neutropenia, pneumoperitoneum, acidosis, and intestinal wall thickness were predictors related to the occurrence of bowel resection. A 6-point scoring system was further developed based on the obtained total coefficient, and the infants could be divided into low-, moderate- and high-risk groups according to cut values of 7 and 13.ConclusionThe results of this study demonstrated that severe NEC features and low birth weight were associated with bowel resection. The risk scoring system could accurately separate infants that were suspected to have bowel loss during surgery.  相似文献   
2.
3.
4.
ObjectiveThe purpose of this review is to describe the myriad complications of cancer and its therapies to emphasize the pathophysiological need for prehabilitation.Data SourcesThe information presented in this review is from applicable, peer-reviewed scientific articles.ConclusionCancer itself renders negative effects on the body, most notably unintentional weight loss and fatigue. Cancer treatments, especially surgical interventions, can cause detrimental short- and long-term impacts on patients, which translate to suboptimal treatment outcomes. Prehabilitation can be used to improve patient health prior to anticancer therapies to improve treatment tolerance and efficacy.Implications for Nursing PracticeNurses play an important role in the treatment of patients with cancer throughout the cancer care continuum. Many nurses are already aiding their patients in cancer prehabilitation through education. By describing common impairments amenable to multimodal prehabilitation, nurses may better advocate for their patients and can become even more involved in this aspect of care.  相似文献   
5.
Huang  Liyan  Li  Wei  Li  Yi  Song  Chaoyuan  Wang  Pin  Wang  Hongchun  Sun  Xiulian 《Neurogenetics》2020,21(1):39-49
neurogenetics - Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is the most common monogenic disease leading to stroke and vascular dementia....  相似文献   
6.
近年来,蚊虫传播的黄热病在非洲和南美洲地区大面积“再流行”,仅南美洲的巴西在一年时间就发现数千例黄热病确诊病例,黄热病已经在非洲和南美洲地区造成巨大的公共卫生负担。此外,在黄热病非流行国家和地区发现大量输入性病例,使得黄热病有可能在非洲和南美洲以外的地区成为“新发传染病”而在世界更大范围流行。为此,世界卫生组织制定了“消除黄热病流行(EYE)”战略,预计利用10年时间在黄热病流行地区接种13.8亿剂量黄热疫苗,以降低黄热病对国际公共卫生健康的危害。  相似文献   
7.
简要介绍了GE宝石能谱CT(Discovery CT750 HD)的技术特点,详细阐述了日常使用中出现的间歇性停机、无法进行Fastcal(快速空气校正)以及扫描中断和gantry(扫描架)自动复位3例故障的维修过程,为医院维修人员维修类似故障提供了参考。最后总结了医疗设备常见故障及主要故障原因,提出了快速排查CT故障的方法,并建议在日常使用中及时保养维护以降低设备故障率。  相似文献   
8.
目的探讨阻塞性睡眠呼吸暂停低通气综合征(OSAHS)CYP3A4基因的多态性,了解其对芬太尼类药物的敏感性及不同基因型的人群分布特征,指导临床个体化用药。方法对50例OSAHS患者进行CYP3A4基因的多态性检测,采静脉血,通过DNA抽提-PCR扩增-焦磷酸测序方法检测CYP3A4基因。结果野生纯合型型34例(68%),突变杂合型15例(30%),突变纯合型型1例(2%)。结论OSAHS患者中约2%为AA型,该型对芬太尼类药物极其敏感,术后有易发生窒息的风险,应高度警惕芬太尼类药物呼吸抑制的潜在风险。  相似文献   
9.
Epidemiological studies on magnesium intake and primary liver cancer (PLC) are scarce, and no prospective studies have examined the associations of magnesium intake with PLC incidence and mortality. We sought to clarify whether higher magnesium intake from diet and supplements was associated with lower risks of PLC incidence and mortality in the US population. Magnesium intake from diet and supplements was evaluated through a food frequency questionnaire in a cohort of 104,025 participants. Cox regression was employed to calculate hazard ratios for PLC incidence and competing risk regression was employed to calculate subdistribution hazard ratios for PLC mortality. Restricted cubic spline regression was employed to test nonlinearity. We documented 116 PLC cases during 1,193,513.5 person-years of follow-up and 100 PLC deaths during 1,198,021.3 person-years of follow-up. Total (diet + supplements) magnesium intake was found to be inversely associated with risks of PLC incidence (hazard ratiotertile 3 vs. 1: 0.44; 95% confidence interval: 0.24, 0.80; ptrend = 0.0065) and mortality (subdistribution hazard ratiotertile 3 vs. 1: 0.37; 95% confidence interval: 0.19, 0.71; ptrend = 0.0008). Similar results were obtained for dietary magnesium intake. Nonlinear inverse dose–response associations with PLC incidence and mortality were observed for both total and dietary magnesium intakes (all pnonlinearity < 0.05). In summary, in the US population, a high magnesium intake is associated with decreased risks of PLC incidence and mortality in a nonlinear dose–response manner. These findings support that increasing the consumption of foods rich in magnesium may be beneficial in reducing PLC incidence and mortality.  相似文献   
10.
Podophyllotoxin (PPT) exhibited significant activity against P-glycoprotein mediated multidrug resistant (MDR) tumor cell lines; however, due to its poor solubility and high toxicity, PPT cannot be dosed systemically, preventing its clinical use for MDR cancer. We developed a nanoparticle dosage form of PPT by covalently conjugating PPT and polyethylene glycol (PEG) with acetylated carboxymethyl cellulose (CMC-Ac) using one-pot esterification chemistry. The polymer conjugates self-assembled into nanoparticles (NPs) of variable sizes (20–120 nm) depending on the PPT-to-PEG molar ratio (2–20). The conjugate with a low PPT/PEG molar ratio of 2 yielded NPs with a mean diameter of 20 nm and released PPT at ∼5%/day in serum, while conjugates with increased PPT/PEG ratios (5 and 20) produced bigger particles (30 nm and 120 nm respectively) that displayed slower drug release (∼2.5%/day and ∼1%/day respectively). The 20 nm particles exhibited 2- to 5-fold enhanced cell killing potency and 5- to 20-fold increased tumor delivery compared to the larger NPs. The biodistribution of the 20 nm PPT-NPs was highly selective to the tumor with 8-fold higher accumulation than all other examined tissues, while the larger PPT-NPs (30 and 120 nm) exhibited increased liver uptake. Within the tumor, >90% of the 20 nm PPT-NPs penetrated to the hypovascular core, while the larger particles were largely restricted in the hypervascular periphery. The 20 nm PPT-NPs displayed significantly improved efficacy against MDR tumors in mice compared to the larger PPT-NPs, native PPT and the standard taxane chemotherapies, with minimal toxicity.  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