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   6485篇
  免费   189篇
  国内免费   97篇
耳鼻咽喉   148篇
儿科学   345篇
妇产科学   147篇
基础医学   342篇
口腔科学   63篇
临床医学   1121篇
内科学   1128篇
皮肤病学   31篇
神经病学   821篇
特种医学   107篇
外科学   1406篇
综合类   262篇
预防医学   317篇
眼科学   15篇
药学   186篇
中国医学   35篇
肿瘤学   297篇
  2023年   92篇
  2022年   173篇
  2021年   340篇
  2020年   269篇
  2019年   282篇
  2018年   332篇
  2017年   260篇
  2016年   209篇
  2015年   242篇
  2014年   537篇
  2013年   575篇
  2012年   292篇
  2011年   400篇
  2010年   335篇
  2009年   383篇
  2008年   402篇
  2007年   357篇
  2006年   299篇
  2005年   206篇
  2004年   144篇
  2003年   94篇
  2002年   76篇
  2001年   69篇
  2000年   82篇
  1999年   69篇
  1998年   41篇
  1997年   49篇
  1996年   32篇
  1995年   26篇
  1994年   19篇
  1993年   4篇
  1992年   10篇
  1991年   14篇
  1990年   7篇
  1989年   8篇
  1988年   7篇
  1987年   5篇
  1986年   6篇
  1985年   10篇
  1984年   7篇
  1983年   1篇
  1982年   1篇
  1981年   3篇
  1979年   1篇
  1977年   1篇
排序方式: 共有6771条查询结果,搜索用时 46 毫秒
1.
《Pancreatology》2022,22(5):598-607
BackgroundResections for intraductal papillary mucinous neoplasia (IPMN) have increased dramatically during the last decade. Recurrence pattern and impact of adjuvant chemotherapy for solid pancreatic ductal adenocarcinoma (PDAC) is well known, but not for invasive IPMN (inv-IPMN).ObjectivesTo elucidate the impact of spatio-temporal recurrence pattern and adjuvant chemotherapy on overall survival for inv-IPMN compared with PDAC.MethodsWe conducted a retrospective single-center observational study of consecutive patients ≥18 years of age who underwent resection for inv-IPMN or PDAC at Karolinska University Hospital, between 2009 and 2018. Different initial recurrence sites and time frames as well as predictors for death were assessed with multivariable Cox and logistic regressions. Survival analyses were performed using the Kaplan-Meier model and log rank test.ResultsOf 396 resected patients, 92 were inv-IPMN and 304 PDAC. Both recurrence rate and death rate within three-years were lower for inv-IPMN compared to PDAC (p = 0.006 and p = 0.007 respectively). Across the whole cohort, the most common recurrence patterns were multi-site (25%), single-site liver (21%) and single-site locoregional (10%) recurrence. The most prominent predictors for death in multivariable Cox regression, especially if occurred within the first year, were multi-site (HR 17.0), single-site peritoneal (HR 13.6) and single-site liver (HR 13.1) recurrence. These predictors were less common in inv-IPMN compared to PDAC (p = 0.007). The effect of adjuvant chemotherapy was similar in the two groups.ConclusionResected inv-IPMN exhibits a less aggressive recurrence pattern than PDAC that translates into a more favorable overall survival.  相似文献   
2.
3.
目的 探讨新生儿双侧声带麻痹的病因、临床特点、治疗及预后转归。 方法 对新生儿中心在2016年1月至2020年12月期间收治的双侧声带麻痹患儿进行回顾性分析,记录患儿的基本资料、病因、治疗情况及预后情况,并对患儿进行门诊及电话随访。 结果 共纳入28例患儿,男18例,女10例,年龄1~24 d,中位年龄3.5 d。92.9%(26/28)的患儿为足月儿,53.6%(15/28)的患儿为剖宫产。患儿首发症状主要为吸气性喉鸣及呼吸困难,占比高达78.6%(22/28),其次为呛奶及呕吐,占比为14.3%(4/28)。先天性双侧声带麻痹23例(82.1%,23/28),其中合并中枢神经系统病变7例(23.8%),先天性心脏病6例(21.4%),喉气管疾病6例(21.4%),胃食管反流疾病2例(7.1%);后天获得性声带麻痹5例(17.9%,5/28),获得性因素中多发于食管、气管疾病术后(80%,4/5)。全部患儿中8例(28.6%)行气管切开。所有患儿随访时间1个月~4年,死亡4例。气管切开患儿8例中,1例12个月时顺利拔管,1例堵管中,余5例目前随访16~47个月声带仍无恢复。观察等待20例患儿中,11例(64.7%)在后期随访的1~38个月内痊愈,声带活动恢复,6例(35.3%)在后期随访的5~17个月内声带活动改善,活动后喉鸣。 结论 新生儿双侧声带麻痹病因以先天性多见,共患病因素多,临床多表现为喉鸣及呼吸困难,部分有吞咽困难。气管切开术在新生儿双侧声带麻痹中并不是普遍必要的,多数先天性双侧声带麻痹患儿可自行恢复,预后较好,不要过早行外科手术干预。  相似文献   
4.
BackgroundValue-based contracts that tie payments for pharmaceuticals to predefined outcomes aim to promote value through shared risk and aligned incentives between manufacturers and payers.MethodsWe conducted a Delphi study among diverse stakeholders (patients, providers, payers, pharmacy benefits managers, pharmaceutical company representatives) to identify top meaningful outcomes for inclusion in value-based contracts for atrial fibrillation medications. The final panel (n = 55) rated the importance of each outcome on a 5-point Likert scale and selected their top 3 most meaningful outcomes. Non-patient participants rated the feasibility of collecting each outcome on a 5-point Likert scale. Consensus was defined as ≥75% agreement (Likert scores ≥4/5 or selection of an outcome as most meaningful). Differences between stakeholder groups were examined using Fisher's Exact Test.ResultsConsensus was achieved for importance of 10 outcomes (Likert scale), where “preventing stroke or mini-stroke” reached 100% agreement (55/55). Eighty-one percent (44/54) of participants selected “preventing stroke or mini-stroke” as the most meaningful outcome (rank order question). The measures rated as most feasibly collected were “reducing hospitalizations” (97%, 36/37) followed by “preventing stroke or mini-stroke” and “reducing emergency department visits” (both 92%, 34/37). There were statistically significant differences between patients and non-patients [0% (0/17) vs 22% (8/37), P = 0.047] and patients and providers [0% (0/17) vs 39% (7/18), P = 0.008] in selection of “improving health-related quality of life” as a most meaningful outcome.ConclusionsThese findings will inform the design of atrial fibrillation value-based pharmaceutical contracts and provide additional insight into preferences for outcomes which could be used to improve the quality of atrial fibrillation care.  相似文献   
5.
ObjectivesTo describe the preoperative characteristics of patients undergoing cataract surgery in our hospital, to determine the final visual and refractive results and to determine the preoperative characteristics that conditioned the presence of a residual refractive error (RRE) greater than one diopter.MethodsRetrospective analysis of cataract surgeries performed at Araba University Hospital between February 2017 and December 2019. Sociodemographic, eye comorbidity, biometric, surgical and post-surgical characteristics were collected.ResultsA total of 1,419 patients and 1,578 surgeries were included for analysis. Of these, 9.07% had preoperative legal blindness, 31.69% eye comorbidity and 4.18% had previous surgery. Overall, 95.82% of patients achieved a corrected final visual acuity (VA) ≥ 0.5 Snellen decimal and 63.12% ≥ 1, and 96.70% of patients improved VA after surgery. RRE was between ± 0.5 diopters in 77.82% of patients and between ± 1 diopter in 94.74%. The most prominent risk factors that conditioned the presence of RRE greater than 1 diopter were the use of ultrasonic contact biometer, a history of glaucoma surgery, the presence of white or hard cataract, and prior legal blindness.ConclusionsThe visual results of cataract surgery were excellent, with 63.12% of patients obtaining corrected VA ≥ 1 and an RRE of ± 1 diopter in 94.74%. Different risk factors influenced the achievement of poor refractive outcomes: preoperative conditions (previous surgeries, white/hard cataract, previous VA) and biometrics.  相似文献   
6.
There is some dissatisfaction with the term “nonalcoholic fatty liver disease (NAFLD),” which overemphasizes alcohol and underemphasizes the importance of metabolic risk factors in this disease. Recently, a consensus recommended “metabolic (dysfunction)-associated fatty liver disease (MAFLD)” as a more appropriate term to describe fatty liver diseases (FLD) associated with metabolic dysfunction. During the definition change from NAFLD to MAFLD, subjects with FLD and metabolic abnormalities, together with other etiologies of liver diseases such as alcohol, virus, or medication who have been excluded from the NAFLD criteria, were added to the MAFLD criteria, while subjects with FLD but without metabolic abnormality, who have been included in the NAFLD criteria, were excluded from the MAFLD criteria. This means that there is an emphasis on the metabolic dysfunction in MAFLD which may underestimate the prognostic value of hepatic steatosis itself, whereas the MAFLD criteria might better identify subjects who are at a higher risk of hepatic or cardiovascular outcomes. However, non-metabolic risk NAFLD subjects who are excluded from the MAFLD criteria are missed from the diagnosis, and their potential risk can be the cause of future diseases. Although huge controversies remain, this review focused on summarizing recent studies that compared the clinical and prognostic characteristics between subjects with NAFLD and MAFLD.  相似文献   
7.
ObjectivesA suicide attempt (SA) is a major risk factor of recurrent SA in adolescence and may be associated with psychological or social problems in the future. REPEATERS is a longitudinal study which examines the long-term psychosocial outcome of adolescents following attempted suicide. It focuses on the impact of early recurrence (i.e., within the first year of the index SA) – data which is, in fact, poorly documented.MethodsTen years after the index SA, a self-reporting questionnaire was sent to all adolescents who had attempted suicide and were followed up by the CHRU (Regional University Hospital Centre) de Nancy, France, between 1994 and 2003 and their parents. The purpose of this questionnaire was to assess psychosocial outcomes. Data concerning SA were collected retrospectively.ResultsAfter ten years, 146 of the 309 adolescents who had attempted suicide and were participating in the study had responded: 90% lived with a partner and 41% had children. The mean (SD) current emotional life of suicide attempt survivors scored 7.3 (2.3) on a scale of 0 to 10. Compared to the general population of the same age, responders felt more depressed than their peers (29% vs. less than 8% of males and 20% of females), had more suicidal thoughts (14% vs. 5%), and had more SAs (27% vs. 0.3%). Moreover, the risk of recurrence over the ten year period was associated with suicide recurrence in the first year after the index SA (odds ratio [OR] = 2.3; 95% confidence interval [CI] = 1.1–4.9) and with a lower level of education at ten years (OR = 0.37; 95% CI = 0.19–0.45).ConclusionsAlthough a favorable outcome was reported ten years after the event for the majority of adolescents who had attempted suicide, some with a lower level of education were nevertheless at increased risk of recurrence and depression. Post-intervention strategies are therefore essential in order to evaluate risk factors which may persist if not taken into consideration.  相似文献   
8.
《Clinical neurophysiology》2021,132(6):1312-1320
ObjectiveTo investigate the additional value of EEG functional connectivity features, in addition to non-coupling EEG features, for outcome prediction of comatose patients after cardiac arrest.MethodsProspective, multicenter cohort study. Coherence, phase locking value, and mutual information were calculated in 19-channel EEGs at 12 h, 24 h and 48 h after cardiac arrest. Three sets of machine learning classification models were trained and validated with functional connectivity, EEG non-coupling features, and a combination of these. Neurological outcome was assessed at six months and categorized as “good” (Cerebral Performance Category [CPC] 1–2) or “poor” (CPC 3–5).ResultsWe included 594 patients (46% good outcome). A sensitivity of 51% (95% CI: 34–56%) at 100% specificity in predicting poor outcome was achieved by the best functional connectivity-based classifier at 12 h after cardiac arrest, while the best non-coupling-based model reached a sensitivity of 32% (0–54%) at 100% specificity using data at 12 h and 48 h. Combination of both sets of features achieved a sensitivity of 73% (50–77%) at 100% specificity.ConclusionFunctional connectivity measures improve EEG based prediction models for poor outcome of postanoxic coma.SignificanceFunctional connectivity features derived from early EEG hold potential to improve outcome prediction of coma after cardiac arrest.  相似文献   
9.
10.
Effective anticoagulation status may determine the recanalization and outcome of cerebral venous thrombosis (CVT). We report impact of anticoagulation status on recanalization and outcome of CVT. This is a retrospective study on 126 patients with CVT diagnosed on magnetic resonance venography (MRV). Their clinical features and risk factors were noted. The data were retrieved from a prospectively maintained registry, and international normalized ratio (INR) was noted after discharge till 3 months. All the patients were on acenocoumarol. Based on INR value, patients were categorized as Group A (effective anticoagulation INR within the therapeutic range or above) and Group B (ineffective anticoagulation INR > 50% below the therapeutic range). A repeat MRV at 3 months was done for recanalization. Outcome at 3 months was evaluated using modified Rankin Scale (mRS), and categorized as good (mRS ≤ 2) and poor (mRS 2 or more) 101(80.2%) patients were in group A and 25(19.8%) in group B. Their demographic, risk factors, magnetic resonance imaging (MRI) and MRV findings were comparable. On repeat MRV, recanalization occurred in 22/24(91.7%); 15(88%) in group A and 7(100%) in group B. Recanalization was independent of coagulation status. Seven (5.6%) patients died and 107(84.9%) had good outcome; 85(84.2%) in group A and 22(88%) in group B. Kaplan Meier analysis also did not reveal survival or good outcome benefits between the groups. In CVT, outcome and recanalization at 3 months are not dependent on coagulation status. Further prospective studies are needed regarding duration of anticoagulant and its impact on recanalization and outcome.  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