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   1728篇
  免费   123篇
  国内免费   45篇
耳鼻咽喉   7篇
儿科学   39篇
妇产科学   22篇
基础医学   88篇
口腔科学   41篇
临床医学   190篇
内科学   163篇
皮肤病学   18篇
神经病学   76篇
特种医学   44篇
外科学   179篇
综合类   349篇
预防医学   363篇
眼科学   64篇
药学   110篇
  3篇
中国医学   93篇
肿瘤学   47篇
  2023年   28篇
  2022年   38篇
  2021年   63篇
  2020年   43篇
  2019年   89篇
  2018年   82篇
  2017年   52篇
  2016年   58篇
  2015年   42篇
  2014年   110篇
  2013年   109篇
  2012年   134篇
  2011年   128篇
  2010年   102篇
  2009年   94篇
  2008年   63篇
  2007年   78篇
  2006年   71篇
  2005年   57篇
  2004年   38篇
  2003年   41篇
  2002年   26篇
  2001年   24篇
  2000年   25篇
  1999年   21篇
  1998年   13篇
  1997年   17篇
  1996年   15篇
  1995年   14篇
  1994年   11篇
  1993年   12篇
  1992年   10篇
  1991年   8篇
  1990年   10篇
  1989年   6篇
  1987年   7篇
  1986年   6篇
  1985年   16篇
  1984年   25篇
  1983年   10篇
  1982年   12篇
  1981年   13篇
  1980年   14篇
  1979年   12篇
  1978年   8篇
  1977年   7篇
  1976年   6篇
  1975年   7篇
  1974年   7篇
  1973年   6篇
排序方式: 共有1896条查询结果,搜索用时 20 毫秒
91.
目的了解2012年循化县居民的死亡情况及死因分布特点,为综合防治提供科学依据。方法利用死亡率、构成比对我县2012年死因监测资料进行描述性统计分析。结果循化县2012年报告粗死亡率为475.00/10万,报告全死因寿命69.4岁;居民死因前6位的疾病为心脏病、脑血管病、胃和十二指肠溃疡、恶性肿瘤、呼吸系统疾病及意外死亡,占全部死因构成的77.25%。结论心脑血管、消化道、恶性肿瘤、呼吸系统等慢性非传染性疾病及意外死亡为影响我县居民健康的主要危害因素,加强慢性非传染性疾病的防制刻不容缓,应积极开展慢性病的监测、防治工作和伤害干预措施。  相似文献   
92.
[目的]分析2003-2013年玉龙县孕产妇情况,探讨孕产妇死亡原因及变化趋势,提出干预措施。[方法]对2003-2013年玉龙县孕产妇监测资料进行分析。[结果]2003-2013年玉龙县出生活产数为19,474例,死亡孕产妇13例,平均死亡率为66.76/10万。孕产妇死因的前三位依次为妊娠合并先天性心脏病、妊娠期高血压病、羊水栓塞及产科出血。[结论]降低玉龙县孕产妇死亡的重点是加强基层医疗保健机构产科建设及产科人员技术培训,提高其对高危妊娠的识别、处理能力、完善转诊机制;提高孕产妇系统管理率,加强孕产妇高危专案管理;加大健康教育宣传力度,提高孕产妇及家庭成员的自我保健意识。  相似文献   
93.
Abstract

Background: Except for pancreas divisum (PD), the prevalence of anatomic variants of the main pancreatic duct (MPD) seems to be insufficiently investigated. To date, their role in the occurrence of pancreatic exocrine insufficiency (PEI) and morphological changes suggestive of chronic pancreatitis (CP) has remained unclear.

Methods: A systematic review was performed, searching MEDLINE and Web of Science, limited to articles published between 1960 and 1 June 2019.

Results: Our review included a total number of 3234 subjects. The most common variant of MPD was type 3, followed by type 1, indicating MPD drainage pattern into major papilla (MP) as the most frequent. A sub-variant of type 3, known as ‘reverse pancreas divisum’ had a prevalence of 2.2%. Type 4 variant- PD, was found in 6.4% of all cases. The most common sub-variant of PD was complete PD, followed by incomplete PD and variant with MPD as only pancreatic duct. Type 5 variant (including ansa pancreatica) was present in 2.9% of subjects. Apart from one study with a significantly higher frequency of morphological changes suggestive of CP in patients with ansa pancreatica, the studies stated no significant association between pancreatic disease and MPD variants. Furthermore, only one study examined the influence of MPD variants on exocrine pancreatic function. Although equivocal, this association is most likely found to be insignificant.

Conclusion: To elucidate linkage between MPD variants and the occurrence of chronic pancreatitis and impairment of pancreatic exocrine function, further clinical investigations are warranted.  相似文献   
94.
Three-dimensional augmentation in severely atrophic bone and after cancer resection is a challenging clinical indication that is mostly solved using autologous bone transplantation. The development of the digital technique along with the additive manufacturing and three-dimensional (3D) printing opened new avenues for reconstructive oral and maxillofacial surgery. Therefore, patient-specific titanium mesh is a novel means of stabilizing the augmentation region using particulate bone substitute materials (BSMs) combined with autologous bone as a minimally invasive concept. However, dehiscence is a frequently reported complication in this field. Therefore, the aim of the present case series was to introduce a biomaterial-based regenerative concept in terms of exposed open healing to overcome the dehiscence related to 3D-titanium meshes. Additionally, this case series presents a novel protocol using a combination of xenogeneic BSMs with an autologous blood concentrate system (platelet-rich fibrin [PRF]) and collagen matrices without any autologous transplantation. Seven patients with alveolar ridge atrophy with different etiologies (cancer resection, severe atrophy after tooth loss, aplasia, trauma, implant infections) were treated using the open-healing concept. Therefore, after 3D augmentation using the described biomaterials, the flap margins were approximated, and the gap between the flap margins was bridged using a collagen matrix loaded with liquid PRF that was then covered by either a PTFE-based membrane or sterile latex. No periosteum splitting was performed at any time point. After a healing period of 4–8 months, all patients received dental implants as virtually planned. Bone biopsies were performed during dental insertion for histological evaluation. The augmentation area displayed a vital and well-vascularized newly formed bone that incorporated the BSM granules to build a hybrid bone. Additionally, open healing resulted in newly formed soft tissue without any signs of scar formation or fibrosis. The regenerated soft tissue was used to build a new flap during implant insertion and showed good functional and aesthetic results after implant insertion. The open-healing concept of the regeneration of the soft tissue along with bone tissue to regenerate a harmonic implantation bed is a minimally invasive intervention without periosteum splitting or large flap mobilization. However, further controlled clinical studies are needed to evaluate this concept in a larger patient cohort to outline the potential clinical benefit.  相似文献   
95.
目的 分析主动脉弓杂交术后并发脑梗死的原因,总结护理方法.方法 对129例Stanford B型主动脉夹层行主动脉弓杂交术患者进行回顾性分析.结果 术后5例(3.88%)并发脑梗死,其中1例并发多脏器功能衰竭家属放弃治疗,治愈出院4例,但均遗留神经系统症状,需进一步行康复治疗.结论 桥血管狭窄或闭塞、主动脉弓部斑块或附壁血栓脱落造成栓塞、术后低血压、伤口血肿及小动脉瘤形成是主动脉弓杂交术后并发脑梗死的原因.对主动脉弓杂交术后患者,除严密观察生命体征、避免低血压的发生外,还要做好神经系统、伤口出血和肢体血运的观察,以预防和及早发现脑梗死并发症.  相似文献   
96.
This study tested whether previously reported associations between early life factors and later adolescent sexual orientation could be replicated in another prospective birth cohort, the UK Millennium Cohort Study (MCS). We used data on 9,795 youth from the MCS. Emerging sexual orientation was assessed using measures of sexual attraction to males and females in separate items at 14 years. Factors including birthweight, breastfeeding, sibling composition, parental ages, maternal psychopathology, parent-child relationship, and contextual risks were separated into three developmental periods: prenatal (n = 5 factors), before 7 years (n = 6 factors), and after 7 years (n = 5 factors). We controlled for handedness as a putative marker of prenatal androgen exposure and the possibility of mischievous responding statistically. Girls with greater maternal psychological distress since age 7 and greater pubertal body mass index were more likely to be nonheterosexual but the effect sizes were very small. Among boys there were no significant associations between any early life conditions and later sexual orientation. However, focusing on effect sizes rather than significance levels, there were small associations between preterm birth and nonheterosexuality. The results offer further evidence that psychosocial influences in the development of adolescent sexual orientation are weak or non-existent.  相似文献   
97.
目的探讨颌面部拆除坚固内固定术后钛板的原因和适应证。方法收集永康市第一人民医院口腔科2001—2005年内行颌面部坚固内固定术后87例取钛板患者,就其原因进行分析。结果本组病例取钛板原因中患者要求31例、感染12例、钛板外露13例、影响发育12例、颞下颌关节功能障碍9例、影响修复8例、其他2例。结论颌面部钛板内固定术后取板原因和适应证包括心理因素、局部因素、功能障碍因素、其他因素。  相似文献   
98.
目的::探讨白内障术后连续环形撕囊(CCC)开口纤维膜闭行开窗术处理的初步临床效果。方法::回顾性系列病例研究。对2011年9月至2018年9月在台州市眼科医院就诊的白内障术后前囊膜CCC开口完全纤维膜闭的患者15例(15眼)行纤维膜开窗切除手术,并对其纤维膜闭形成原因、手术方式和效果进行了探讨。结果::所有术眼术后视...  相似文献   
99.
死因监测中根本死因填报存在问题及解决途径   总被引:4,自引:1,他引:3       下载免费PDF全文
封宝琴  李海平  张晓平 《疾病监测》2006,21(11):585-589
目的提高根本死因填报准确性,准确定量死因构成,确定重点防制的重大疾病,为制定疾病预防与控制策略提供依据。方法数据来源于太原市区县疾控中心上报死亡个案,MicroAccess建库、清洗、统计。结果2005年报告死亡病例数为5554例,根本死因填报正确率为74.97%,根本死因填报错误率为25.03%。其中,错误项中症状或体征构成比最高,为47.08%,其次为各种衰竭,构成比为31.97%。造成根本死因填报错误的主要原因是:个别医生对根本死因概念不清《:居民死亡医学证明书》中死因链填写不规范。2006年监测数据表明,培训前后,死因链正确率由64.26%上升到70.98%,根本死因正确率由74.50%上升为82.44%。结论死因监测中根本死因判定不准确的问题,是影响监测质量的关键因素,通过探讨有效的死因监测系统管理模式,增强死因监测人才的能力建设,可有效的解决根本死因判定不准确的问题,使死因监测系统得以健康发展。  相似文献   
100.
目的:探讨抗β2糖蛋白I型抗体(抗β2 GPI抗体)与急性冠脉综合征(ACS)的临床相关性。方法:采用酶联免疫吸附法检测168例ACS患者血清中抗β2 GPI抗体的浓度水平,同时进行冠脉造影术检查,并对罪犯血管进行血管重建。根据抗体浓度水平分为高、中、低浓度组,分析各组中抗体浓度与ACS临床分型[急性ST段抬高型心肌梗死(STEMI)、急性非ST段抬高型心肌梗死(NSTEMI)、中危以上不稳定型心绞痛(UA)]的相关性,随访12个月,评价抗β2 GPI抗体浓度与ACS患者的疾病严重程度及主要不良心血管事件(MACEs)的相关性。结果:ACS中STEMI、NSTEMI、UA患者抗β2 GPI抗体浓度依次是(63.4±32.6)RU/ml,(39.8±25.9)RU/ml,(22.1±10.4)RU/ml,其中STEMI患者抗体浓度较高,UA患者的抗体浓度最低。抗β2GPI抗体的高浓度组中STEMI(10/11)占90.9%,高于中浓度组(29/96)和低浓度组(1/61)(P〈0.01)。随访观察12个月,随访率98%;抗β2 GPI抗体高浓度组有4例发生MACEs,发生率36.4%,显著高于中浓度组(4.2%)和低浓度组(3.5%)。多因素回归分析提示抗β2GPI抗体高浓度是预测ACS发生MACEs的独立危险因素之一。结论:抗β2 GPI抗体浓度与ACS患者疾病的严重程度及MACEs密切相关,抗β2 GPI抗体高浓度是ACS再发MACEs的独立危险因素之一。  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