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   67518篇
  免费   4604篇
  国内免费   1342篇
耳鼻咽喉   105篇
儿科学   1849篇
妇产科学   4233篇
基础医学   4038篇
口腔科学   505篇
临床医学   8267篇
内科学   18244篇
皮肤病学   267篇
神经病学   732篇
特种医学   1051篇
外国民族医学   17篇
外科学   6996篇
综合类   11393篇
预防医学   3120篇
眼科学   92篇
药学   5867篇
  53篇
中国医学   3064篇
肿瘤学   3571篇
  2024年   19篇
  2023年   1064篇
  2022年   1488篇
  2021年   2546篇
  2020年   2684篇
  2019年   2214篇
  2018年   2168篇
  2017年   2279篇
  2016年   2277篇
  2015年   2340篇
  2014年   4923篇
  2013年   5169篇
  2012年   3881篇
  2011年   4487篇
  2010年   3556篇
  2009年   3488篇
  2008年   3443篇
  2007年   3481篇
  2006年   3217篇
  2005年   2949篇
  2004年   2254篇
  2003年   1949篇
  2002年   1616篇
  2001年   1494篇
  2000年   1141篇
  1999年   915篇
  1998年   724篇
  1997年   663篇
  1996年   631篇
  1995年   586篇
  1994年   553篇
  1993年   402篇
  1992年   361篇
  1991年   349篇
  1990年   295篇
  1989年   287篇
  1988年   264篇
  1987年   199篇
  1986年   162篇
  1985年   162篇
  1984年   154篇
  1983年   93篇
  1982年   98篇
  1981年   87篇
  1980年   69篇
  1979年   73篇
  1978年   53篇
  1977年   37篇
  1976年   43篇
  1974年   19篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
目的 探讨以目标为导向的护理干预对心力衰竭患者疾病认知水平及生活质量的影响。方法 将本院2020年2月—2022年2月接收的110例慢性心力衰竭患者根据随机数字表法分为对照组(给予常规护理)与干预组(给予目标为导向的护理),各55例,比较2组患者3个月后的疾病认知及行为水平、心功能及生活质量(MLHFQ)评分变化。结果 干预后,6MWT干预组为(442.64±131.53),高于对照组的(332.58±119.82),t=4.588,P<0.001;干预组的BNP为(539.54±193.57),低于对照组的(812.37±127.65),t=-8.726,P<0.001;干预组的LVEF为(54.46±5.86),高于对照组的(48.58±3.47),t=6.403,P<0.001;差异均具有统计学意义。干预组的疾病认知评分为(51.46±3.73),高于对照组的(45.62±3.25),t=8.754,P<0.001;干预组的行为评分为(50.11±3.32),高于对照组的(36.38±3.14),t=-22.283,P<0.001;差异均具有统计学意义。干预组的MLHFQ评分为(18.45±8.69),低于对照组的(41.25±7.15),t=-15.026,P<0.001,差异有统计学意义。结论 对慢性心力衰竭患者给予目标为导向的护理干预效果较好,可提高患者疾病认知水平,转变患者日常行为,改善患者的心功能与生活质量水平。  相似文献   
2.
BackgroundIschemia reperfusion (I/R) play an imperative role in the expansion of cardiovascular disease. Sinomenine (SM) has been exhibited to possess antioxidant, anticancer, anti-inflammatory, antiviral and anticarcinogenic properties. The aim of the study was scrutinized the cardioprotective effect of SM against I/R injury in rat.MethodsRat were randomly divided into normal control (NC), I/R control and I/R + SM (5, 10 and 20 mg/kg), respectively. Ventricular arrhythmias, body weight and heart weight were estimated. Antioxidant, inflammatory cytokines, inflammatory mediators and plasmin system indicator were accessed.ResultsPre-treated SM group rats exhibited the reduction in the duration and incidence of ventricular fibrillation, ventricular ectopic beat (VEB) and ventricular tachycardia along with suppression of arrhythmia score during the ischemia (30 and 120 min). SM treated rats significantly (P < 0.001) altered the level of antioxidant parameters. SM treatment significantly (P < 0.001) repressed the level of creatine kinase MB (CK-MB), creatine kinase (CK) and troponin I (Tnl). SM treated rats significantly (P < 0.001) repressed the tissue factor (TF), thromboxane B2 (TXB2), plasminogen activator inhibitor 1 (PAI-1) and plasma fibrinogen (Fbg) and inflammatory cytokines and inflammatory mediators.ConclusionOur result clearly indicated that SM plays anti-arrhythmia effect in I/R injury in the rats via alteration of oxidative stress and inflammatory reaction.  相似文献   
3.
目的观察医护一体化管理模式对沙库巴曲缬沙坦治疗老年心力衰竭患者用药依从性及并发症的影响。 方法纳入2020年1月至12月江苏省人民医院心血管内科收治的老年心力衰竭患者106例,入院后给予强心、利尿等常规治疗,并在常规治疗的基础上加用沙库巴曲缬沙坦治疗。将106例患者按入院后管理方式的不同分为2组,对照组55例采用常规管理,医护一体化组51例采用医护一体化模式管理,患者出院后随访6个月。观察2组患者出院后总有效率、满意度、依从性和并发症发生率的差异。 结果出院后6个月随访可见,与对照组相比,医护一体化组患者并发症发生率显著降低(P<0.05),而总有效率、用药依从性和满意度均显著提高(P<0.05)。 结论对沙库巴曲缬沙坦治疗的老年心力衰竭患者而言,采用医护一体化管理模式可有效提高患者出院后的用药依从性,在提高总体疗效的同时还降低了并发症发生率。  相似文献   
4.
[摘要] 目的:观察常规抗心衰药物基础上换用沙库巴曲缬沙坦钠(Sacubitril/Valsartan,LCZ696)对慢性心力衰竭合并肾功能不全患者的临床疗效。方法:回顾性分析2018年9月至2020年9月在复旦大学附属闵行医院心内科治疗的射血分数降低型心力衰竭(HFrEF)合并肾功能不全患者196例,所有患者均接受指南导向药物治疗(GDMT),患者在抗心衰标准药物治疗基础上将ACEI/ARB替换为LCZ696治疗,平均观察(9.3±3.6)个月。比较患者治疗前后纽约心功能分级(NYHA),生活质量评分的变化,左心室射血分数(LVEF)、左心室舒张末内径(LVEDD)、血浆N-端脑钠肽前体(NT-proBNP)水平、eGFR及血钾的变化。结果:治疗后LVEF较治疗前显著升高,LVEDD较治疗前明显降低(P<0.001),NYHA分级明显改善(P<0.001); NT-ProBNP较治疗前明显降低(P<0.001)。治疗后躯体、情绪、其他领域及总分均较治疗前明显降低(P<0.05)。诊室日间收缩压和家庭自测夜间收缩压与治疗前相比均显著降低(P<0.05;P<0.01),eGFR较治疗前明显升高(P<0.01),血钾无明显变化(P>0.05)。结论:HFrEF合并肾功能不全患者在标准抗心衰药物治疗基础上换用LCZ696能明显改善NYHA分级、肾功能和生活质量评分,降低NT-ProBNP,对血钾无明显影响。符合适应症的慢性心衰合并肾功能不全患者应用沙库巴曲缬沙坦钠安全有效。  相似文献   
5.
6.
ObjectivePreterm infants are subjected to numerous painful procedures during their neonatal intensive care unit (NICU) hospitalization. Despite advancements in pain alleviation, nurses remain challenged to provide timely and effective pain management for preterm infants. Greater understanding of the lived experience of nurses caring for preterm infants in pain could provide novel insights to improve pain management for this vulnerable population. The aim of this meta-ethnography was to synthesize and interpret qualitative findings of nurses’ experiences of taking care of preterm infants in pain.MethodsAn extensive literature search in PubMed, CINAHL, PsycINFO, Scopus, BIOSIS and ProQuest Dissertation and Theses Database was conducted, including studies within the past 10 years. Two nursing researchers conducted data extraction and analysis independently. Inclusion criteria were applied to search for qualitative studies of nurse participants who worked in the NICU taking care of preterm infants. Studies published in a language other than English, articles that did not include qualitative data and qualitative data that could not be extracted from the findings or did not discuss nurses’ experiences were excluded. Critical Appraisal Skills Programme was used for literature quality evaluation.ResultsEight studies remained after further screening according to inclusion and exclusion criteria. These eight studies were conducted from 2013 to 2018 and totally enrolled 205 nurses from Iran, Canada, the United States, Finland, Sweden, Switzerland, and Australia. Five themes emerged on the nurses’ perspectives of taking care of preterm infants in pain: 1) They sense the neonatal pain; 2) Adverse consequences of unrelieved pain; 3) Barriers of managing pain; 4) Concerns of available approaches for pain relief; 5) Failure to work with parents.ConclusionsThis meta-ethnography identified nurses’ understanding of pain in preterm infants that can be assessed, and they acknowledged that unrelieved pain could cause developmental deficits in infants. The barriers are lack of training and support on pain assessment and intervention in preterm infants. Optimizing workload and environment, developing age-specified pain assessment and intervention, receiving emotional support and training, and building up a rapport with parents are urgent needs for nurses to provide better care to infants having pain.  相似文献   
7.
目的 探讨扩散峰度成像(DKI)对Ⅰ型与Ⅱ型上皮性卵巢癌(EOC)的鉴别诊断价值。 方法 回顾性收集经手术病理证实的45例EOC病人的临床、病理及影像资料,平均年龄(50±13)岁。根据术后病理结果对EOC病人进行分组,分为Ⅰ型组(24例)和Ⅱ型组(21例)。所有病人均于术前行盆腔DKI检查,由2名放射科医师在DKI各参数伪彩图上分别测量平均扩散峰度(MK)、平行扩散峰度(Ka)、垂直扩散峰度(Kr)、平均扩散系数(MD)、平行扩散系数(Da)、垂直扩散系数(Dr)、各向异性分数(FA)、峰度各向异性分数(FAk)。采用Fisher确切概率检验、独立样本t检验或Mann-Whitney U检验比较2组间临床、病理及影像资料的差异,对差异有统计学意义的参数绘制受试者操作特征(ROC)曲线,分析其鉴别诊断效能。 结果 病理表现上,Ⅰ型中交界性肿瘤占比最高(50.0%),Ⅱ型中浆液性癌占比最高(61.9%);Ⅰ型中高分化癌占50%,Ⅱ型多表现为中低分化癌 (76.2%),Ⅰ型EOC的分化程度高于Ⅱ型;Ⅰ型多数处于Ⅰ期(79.2%),Ⅱ型多处于Ⅲ期(57.1%)(均P<0.05)。MRI影像上, Ⅰ型病灶多表现为囊性(41.7%)或囊实性(33.3%),Ⅱ型多表现为实性(52.3%);Ⅱ型(66.7%)腹水发生率高于Ⅰ型(29.2%)(均P<0.05)。Ⅰ型的MK、Ka和Kr值低于Ⅱ型,MD、Da和Dr值高于Ⅱ型(均P<0.05)。ROC曲线分析显示,MK阈值为0.504时,鉴别2组诊断的曲线下面积(AUC,0.817)最大,诊断敏感度(95.2%)、阴性预测值(92.9%)、准确度(78.9%)也最高,Da阈值为2.190时鉴别诊断的AUC(0.770)最小,而特异度(76.2%)、阳性预测值(75.9%)最高。 结论 DKI序列的定量参数MK、Ka、Kr、MD、Da及Dr均有助于鉴别Ⅰ型与Ⅱ型EOC,其中MK值鉴别诊断效能更大。  相似文献   
8.
IntroductionSurgery is the cornerstone of the treatment for advanced ovarian cancer. Reaching complete cytoreduction resulting in no gross residual disease often requires complex surgery. The aim of this study was to assess the impact of increased surgical radicality on the risk of complications in the treatment of advanced ovarian cancer.Materials and methodsAll consecutive patients with advanced ovarian cancer (FIGO Stage IIIB-IVB) who had undergone primary or interval debulking surgery during a six-year study period were identified. In the midst of the study period, a surgical practice change towards maximal surgical effort occurred. Two groups were formed for the analysis: cohort A, that consisted of patients operated before the surgical paradigm shift and cohort B, that consisted of patients operated under the period of increased surgical radicality.Results252 patients were included in the analysis. Complete resection (R0) was achieved in 21.3% of surgeries in cohort A and in 51.2% in cohort B. The total postoperative complication rate was 76.2%. Most of the complications (86.5%) were minor (Clavien-Dindo I-IIIA). The patients in cohort B were at increased risk for complications, OR 2.94 (95%CI 1.58–5.47; p = 0.001). As for the approach to cytoreduction (primary vs. interval debulking), there was no statistically significant association with the occurrence of postoperative complications (p = 0.659).ConclusionIn the present study more extensive surgeries led to better surgical results but increased postoperative morbidity. Postoperative complication rates were similar in both primary and interval debulking surgeries.  相似文献   
9.
《Journal of endodontics》2022,48(9):1092-1099
IntroductionFew data are available on the long-term efficacy of mineral trioxide aggregate (MTA) in treating root canal perforations. This prospective cohort study builds on a previously reported trial to determine the outcome for teeth with root perforations treated with orthograde MTA after longer follow-up and identify potential prognostic factors.MethodsA prospective cohort study was performed, enrolling (1999–2009) patients with a single dental perforation treated with MTA. Preoperative, intraoperative, and postoperative information was evaluated, and the outcomes were dichotomized as healed or nonhealing. Patients were followed up yearly until 2018 for a maximum of 17 years after treatment, with controls carried out until 14 years. Clinical and radiographic outcomes were evaluated using standardized follow-up protocols.ResultsOf the 124 entrolled patients (median age = 36.5 years, 53.2% male), 115 were healed at the first (n = 110, 89%) or second (n = 5, 4%) annual posttreatment checkup, while 9 subjects (7%, 4 females, 18–65 years old) did not heal. Characteristics significantly associated with nonhealing were gender, positive probing, size, and perforation site. Perforations recurred in 48 teeth during the follow-up with the estimated probability of reversal at 5, 10, and 14 years of 6% (95% confidence interval [CI], 2%–10%), 30% (95% CI, 20%–38%), and 62% (95% CI, 46%–73%), respectively. Positive probing had a higher reversal risk (hazard ratio = 3.3, P ≤ .001), and perforations >3 mm were more likely to have a reversal (hazard ratio = 4.1, P < .001).ConclusionsThe risk of reversal for healed MTA-treated root canal perforations, initially relatively low, vastly increases over time.  相似文献   
10.
Heart failure (HF) has high event rates, mortality, and is challenging to manage in clinical practice. Clinical management is complicated by complex therapeutic strategies in a population with a high prevalence of comorbidity and general frailty. In the last four years, an abundance of research has become available to support multidisciplinary management of heart failure from within the hospital through to discharge and primary care as well as supporting diagnosis and comorbidity management. Within the hospital setting, recent evidence supports sacubitril-valsartan combination in frail, deteriorating or de novo patients with LVEF  40%. Furthermore, new strategies such as SGLT2 inhibitors and vericiguat provide further benefit for patients with decompensating HF. Studies with tafamidis report major clinical benefits specifically for patients with ATTR cardiac amyloidosis, a remaining underdiagnosed and undertreated disease. New evidence for medical interventions supports his bundle pacing to reduce QRS width and improve haemodynamics as well as ICD defibrillation for non-ischemic cardiomyopathy. The Mitraclip reduces hospitalisations and mortality in patients with symptomatic, secondary mitral regurgitation and ablation reduces mortality and hospitalisations in patients with paroxysmal and persistent atrial fibrillation. In end-stage HF, the 2018 French Heart Allocation policy should improve access to heart transplants for stable, ambulatory patients and, mechanical circulatory support should be considered to avoid deteriorating on the waiting list. In the community, new evidence supports that improving discharge education, treatment and patient support improves outcomes. The authors believe that this review fills the gap between the guidelines and clinical practice and provides practical recommendations to improve HF management.  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