全文获取类型
收费全文 | 16648篇 |
免费 | 1602篇 |
国内免费 | 288篇 |
专业分类
耳鼻咽喉 | 56篇 |
儿科学 | 318篇 |
妇产科学 | 125篇 |
基础医学 | 1709篇 |
口腔科学 | 260篇 |
临床医学 | 1652篇 |
内科学 | 2212篇 |
皮肤病学 | 136篇 |
神经病学 | 726篇 |
特种医学 | 803篇 |
外国民族医学 | 2篇 |
外科学 | 3406篇 |
综合类 | 1709篇 |
一般理论 | 3篇 |
预防医学 | 3057篇 |
眼科学 | 184篇 |
药学 | 1319篇 |
4篇 | |
中国医学 | 276篇 |
肿瘤学 | 581篇 |
出版年
2024年 | 12篇 |
2023年 | 332篇 |
2022年 | 423篇 |
2021年 | 648篇 |
2020年 | 733篇 |
2019年 | 675篇 |
2018年 | 558篇 |
2017年 | 639篇 |
2016年 | 602篇 |
2015年 | 667篇 |
2014年 | 1205篇 |
2013年 | 1276篇 |
2012年 | 1075篇 |
2011年 | 1125篇 |
2010年 | 905篇 |
2009年 | 910篇 |
2008年 | 895篇 |
2007年 | 891篇 |
2006年 | 729篇 |
2005年 | 651篇 |
2004年 | 549篇 |
2003年 | 418篇 |
2002年 | 382篇 |
2001年 | 350篇 |
2000年 | 267篇 |
1999年 | 206篇 |
1998年 | 180篇 |
1997年 | 168篇 |
1996年 | 145篇 |
1995年 | 117篇 |
1994年 | 108篇 |
1993年 | 89篇 |
1992年 | 94篇 |
1991年 | 82篇 |
1990年 | 49篇 |
1989年 | 39篇 |
1988年 | 54篇 |
1987年 | 40篇 |
1986年 | 32篇 |
1985年 | 42篇 |
1984年 | 24篇 |
1983年 | 20篇 |
1982年 | 16篇 |
1981年 | 22篇 |
1980年 | 23篇 |
1979年 | 17篇 |
1978年 | 14篇 |
1977年 | 24篇 |
1976年 | 4篇 |
1973年 | 4篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
《Archivos de bronconeumología》2022,58(12):802-808
IntroductionThe main aim of this study was to assess the utility of differential white cell count and cell population data (CPD) for the detection of COVID-19 in patients admitted for community-acquired pneumonia (CAP) of different etiologies.MethodsThis was a multicenter, observational, prospective study of adults aged ≥18 years admitted to three teaching hospitals in Spain from November 2019 to November 2021 with a diagnosis of CAP. At baseline, a Sysmex XN-20 analyzer was used to obtain detailed information related to the activation status and functional activity of white cells.ResultsThe sample was split into derivation and validation cohorts of 1065 and 717 patients, respectively. In the derivation cohort, COVID-19 was confirmed in 791 patients and ruled out in 274 patients, with mean ages of 62.13 (14.37) and 65.42 (16.62) years, respectively (p < 0.001). There were significant differences in all CPD parameters except MO-Y. The multivariate prediction model showed that lower NE-X, NE-WY, LY-Z, LY-WY, MO-WX, MO-WY, and MO-Z values and neutrophil-to-lymphocyte ratio were related to COVID-19 etiology with an AUC of 0.819 (0.790, 0.846). No significant differences were found comparing this model to another including biomarkers (p = 0.18).ConclusionsAbnormalities in white blood cell morphology based on a few cell population data values as well as NLR were able to accurately identify COVID-19 etiology. Moreover, systemic inflammation biomarkers currently used were unable to improve the predictive ability. We conclude that new peripheral blood biomarkers can help determine the etiology of CAP fast and inexpensively. 相似文献
2.
BackgroundPost-operative elderly hip fracture patients require significant rehabilitation. Nandrolone is an anabolic steroid used to promote muscle growth. This study aims to examine the effect of nandrolone in improving rehabilitation and quality of life in elderly female patients with hip fractures undergoing hemiarthroplasty.MethodsThis is a double-blinded prospective randomized-controlled-trial consisting of female patients above the age of 65 with an isolated neck of femur fracture planned for a hip hemiarthroplasty. Participants were randomized into two arms of the study – 50 mg intramuscular nandrolone vs normal saline placebo administered on post-operative day 0, and weeks 2, 6 and 12. The participants were followed up across a 1-year period following the surgery. Clinical outcomes such as time taken to achieve rehabilitation milestones, distance of ambulation and thigh muscle girth, and functional scoring with SF-36 questionnaire were recorded at intervals of 2, 6 and 12 weeks, 6 months and 1 year following the surgery.ResultsThere were a total of 23 subjects with 11 in the steroid group and 12 in the placebo group. There was no significant difference in demographics and injury patterns between both groups. There was no significant difference for time taken to achieve various rehabilitation milestones and distance of ambulation. SF-36 scores on discharge and at 1-year follow-up mark were comparable. There was no difference in the complication rate between both groups.ConclusionIntra-muscular Nandrolone after hip surgery in elderly female patients does not result in short to mid-term improved rehabilitation or functional outcomes. Nandrolone did not result in increased short-term complications after hip surgery.Level of evidenceI. 相似文献
3.
[摘要] 目的 了解开封地区无偿献血人群HIV感染状况和流行特征,为献血招募、降低输血途径传播HIV及确保临床用血安全提供依据。方法 采用2种不同厂家ELISA试剂和核酸试剂对2013—2020年间539 015例献血者标本进行HIV初筛,结果呈阳性者送开封市疾病预防控制中心确证实验室确证。分析和比较不同特征献血人群HIV感染状况和流行特征。结果 539 015例献血者标本中,HIV初筛阳性120例(2.23/万),经确证HIV阳性53例(0.98/万)。2013—2020年男性献血者HIV阳性率和献血者HIV总阳性率均呈下降趋势。确证后标本HIV阳性率男性(1.34/万)高于女性(0.39/万),首次献血(3.17/万)高于重复献血(0.38/万),全血(1.05/万)高于单采血小板(0.22/万),外地户籍(2.39/万)高于本市户籍(0.91/万),差异均有统计学意义(P均<0.05)。26~35岁(1.52/万)HIV阳性率高于其他年龄段,差异有统计学意义(P<0.05)。53例HIV阳性献血者中,单纯HIV阳性41例(77.36%),HIV合并其他病原体感染者12例(22.64%)。结论 2013年以来开封地区献血人群HIV阳性率呈下降趋势,HIV感染者主要发生于青年男性、捐献全血、首次献血、低学历、公司职员及外地户籍献血人群。加强献血前征询及建立低危/稳定的献血队伍可降低/避免输血传播HIV风险。 相似文献
4.
5.
Given that the global population of elderly individuals is expanding and the difficulty of recovery, hip fractures will be a huge challenge and a critical health issue for all of humanity. Although people have spent more time at home during the coronavirus disease 2019 (COVID-19) pandemic, hip fractures show no sign of abating. Extensive studies have shown that patients with hip fracture and COVID-19 have a multifold increase in mortality compared to those uninfected and a more complex clinical condition. At present, no detailed research has systematically analyzed the relationship between these two conditions and proposed a comprehensive solution. This article aims to systematically review the impact of COVID-19 on hip fracture and provide practical suggestions. We found that hip fracture patients with COVID-19 have higher mortality rates and more complicated clinical outcomes. Indirectly, COVID-19 prevents hip fracture patients from receiving regular medical treatment. With regard to the problems we encounter, we provide clinical recommendations based on existing research evidence and a clinical flowchart for the management of hip fracture patients who are COVID-19 positive. Our study will help clinicians adequately prepare in advance when dealing with such patients and optimize treatment decisions. 相似文献
6.
Marta Krenz-Niedbała Sylwia Łukasik Jakub Macudziński Szymon Chowański 《Anatomical record (Hoboken, N.J. : 2007)》2022,305(8):1947-1961
Human auditory ossicles, the malleus, the incus, and the stapes, are located in the tympanic cavity in the temporal bone and through forming a chain for the sound transmission from the tympanic membrane to the cochlea, they play an important role in the hearing process. Despite their clinical, phylogenetic, and evolutionary significance, the morphometry of the human ear bones has not been examined systematically. The ear ossicles are the smallest bones of the human skeleton, attaining their final size and morphology already at birth. Initially, they have been found to exhibit minimal morphometric variation, but further studies brought the opposite results. The aim of this study was to examine the morphometric variation of human auditory ossicles recovered from medieval and postmedieval subadult skeletons from Poland, Central Europe. The analysis involved in a total of 166 ear bones. Their measurements were performed on microscopic images using CorelDraw x4, according to a protocol of Quam and Rak with modification of Flohr et al. and Wadhwa et al. Our study showed a significant metric variation in the measurements taken at areas of the greatest morphological variability of the ossicles. We found that greater linear dimensions were associated with lower values of angular measurements. These results reveal the inherent variation found in these supposed functionally constrained structures. Representation of even greater number of populations, time periods, and developmental stages are needed. Further study will expand our understanding of the global scope of variation found in ear ossicular morphology and its functional implications for paleoanthropology. 相似文献
7.
《The Journal for Nurse Practitioners》2022,18(2):164-167
Acute diarrhea is a condition of increased water stool content, stool volume, and number of bowel movements that lasts less than 14 days. Mild diarrhea is usually self-limiting; however, undertreated moderate to severe diarrhea may cause severe dehydration and lead to hypovolemic shock. In order to prevent severe dehydration and treat patients appropriately, it is crucial for health care providers to determine the right diagnosis of patients with acute diarrhea. This article focuses on pathophysiology, general patient presentation, diagnostic tests and differential diagnosis lists of acute diarrhea to discuss which diagnosis should be made based on patient presentation and objective data. 相似文献
8.
《Journal of vascular and interventional radiology : JVIR》2022,33(10):1143-1150
PurposeTo report the 5-year results from the Pivotal Multicenter Trial of Ultrasound-Guided Percutaneous Arteriovenous Fistula (pAVF) Creation for Hemodialysis Access.Materials and MethodsThe retrospective review of 107 intent-to-treat (ITT) patients from the pivotal trial provided a long-term follow-up population (LTP) of 85 patients with a median follow-up duration of 50 months (range, 12–60 months). Data evaluated in the LTP group were fistula maturation and usage, secondary procedures, and complications. The Kaplan-Meier analysis of primary patency, assisted primary patency, cumulative patency, and functional patency (time from 2-needle cannulation to abandonment) were performed for the ITT population.ResultsIn the LTP, 99% (84 of 85) of fistulae were mature, with 99% (78 of 79) of patients requiring hemodialysis using their pAVF. Sustained fistula use (2-needle cannulation at the prescribed rate, 2 of 3 sessions) was achieved in 92% (78 of 85) of patients, with 7 patients not using their pAVF because they were not on dialysis (n = 4), were on peritoneal dialysis (n = 2), and refused to use fistula (n = 1). Fistula maintenance was required in 31.8% (27 of 85) of patients and included fistula dysfunction (21.2%), thrombosis (5.9%), cannulation injury (12.9%), and arm swelling (4.7%). The number of procedures performed per patient per year to maintain function and patency was 0.32 (91 of 288) for years 2–5. The cumulative patency rates were 89.5%, 88.4%, 88.4%, 85.6%, and 82.0% for years 1, 2, 3, 4, and 5, respectively. The functional patency was 91.8% at the end of the study. There were no major complications related to pAVF during the long-term follow-up.ConclusionsPercutaneous fistulae have provided clinically effective and durable access for hemodialysis with low complications. The continued use and evaluation of pAVF are warranted. 相似文献
9.
10.
目的 分析我国中老年人群抑郁症状,探讨健康相关行为与抑郁间的关联性,为改善中老年抑郁干预措施及政策制定提供依据。方法 采用2018年中国健康与养老追踪调查数据,运用关联规则Apriori算法分析健康相关行为与抑郁症状间的关联,并依据支持度、置信度、提升度评价健康行为对抑郁症状的影响。结果 在8 681名调查对象中,抑郁症状的发生率为40.3%;健康相关行为与抑郁症状的关联规则中的强关联规则为无体力活动、睡眠不足、不饮酒的人更易产生抑郁症状;男性中为无体力活动、吸烟、无社交活动的人更易产生抑郁症状;女性中无体力活动、无社交活动、睡眠不足的人更易产生抑郁症状。结论 健康相关行为与抑郁是相互关联的,可通过针对多种行为的联合干预,改善中老年人的抑郁症状。 相似文献