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   22553篇
  免费   1780篇
  国内免费   36篇
耳鼻咽喉   507篇
儿科学   601篇
妇产科学   388篇
基础医学   2816篇
口腔科学   325篇
临床医学   2804篇
内科学   4189篇
皮肤病学   422篇
神经病学   2000篇
特种医学   938篇
外科学   3570篇
综合类   412篇
一般理论   20篇
预防医学   2021篇
眼科学   426篇
药学   1431篇
中国医学   14篇
肿瘤学   1485篇
  2023年   248篇
  2022年   378篇
  2021年   923篇
  2020年   538篇
  2019年   837篇
  2018年   963篇
  2017年   599篇
  2016年   608篇
  2015年   680篇
  2014年   933篇
  2013年   1436篇
  2012年   1689篇
  2011年   1597篇
  2010年   853篇
  2009年   701篇
  2008年   1112篇
  2007年   1128篇
  2006年   998篇
  2005年   848篇
  2004年   859篇
  2003年   653篇
  2002年   614篇
  2001年   367篇
  2000年   415篇
  1999年   339篇
  1998年   149篇
  1997年   124篇
  1996年   109篇
  1995年   93篇
  1994年   88篇
  1993年   89篇
  1992年   257篇
  1991年   219篇
  1990年   226篇
  1989年   233篇
  1988年   223篇
  1987年   193篇
  1986年   253篇
  1985年   168篇
  1984年   152篇
  1983年   124篇
  1982年   91篇
  1981年   85篇
  1980年   88篇
  1979年   160篇
  1978年   94篇
  1976年   74篇
  1975年   77篇
  1971年   77篇
  1970年   71篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
BackgroundComplications and patient-reported outcomes (PROs) of total hip arthroplasty (THA) in patients with Legg-Calve-Perthes disease (LCPD) have demonstrated variable results. The purpose of this study was to use a validated grading scheme to analyze complications associated with THA in patients with residual LCPD deformities. Second, we report PROs and intermediate-term survivorship in this patient population.MethodsA retrospective, single-center review was performed on 61 hips in 61 patients who underwent THA for residual Perthes disease. Average patient age was 42 years and 26% of hips had previous surgery. Complications were determined and categorized using a validated grading scheme that included five grades based on the treatment required to manage the complication and on persistent disability. PROs were compared from preoperative to most recent follow-up time points.ResultsMajor complications (grade III) occurred in three patients (5%) which each required a second surgical intervention. The most common minor grade I or II complications (11.5%) were asymptomatic heterotopic ossification (3.3%). Patients were lengthened on the surgical side an average of 1.4 cm with no nerve palsies. All patient PROs improved from preoperative to postoperative time points with the modified Harris Hip Score improving from 46.9 preoperatively to 85.4 postoperatively (P < .01). Patients free from revision for any reason at final follow-up (5.6 years; range 2-13 years) was 98.4% with one patient needing a revision of their femoral component.ConclusionsTHA for the sequelae of the LCPD has an acceptable complication rate and provides excellent patient reported outcomes at mid-term follow-up.  相似文献   
102.
BackgroundThe principal triggers for intervention in the setting of pediatric blunt solid organ injury (BSOI) are declining hemoglobin values and hemodynamic instability. The clinical management of BSOI is, however, complex. We therefore hypothesized that state-of-art machine learning (computer-based) algorithms could be leveraged to discover new combinations of clinical variables that might herald the need for an escalation in care. We developed algorithms to predict the need for massive transfusion (MT), failure of non-operative management (NOM), mortality, and successful non-operative management without intervention, all within 4 hours of emergency department (ED) presentation.MethodsChildren (≤ 18 years) who sustained a BSOI (liver, spleen, and/or kidney) between 2009 and 2018 were identified in the trauma registry at a pediatric level 1 trauma center. Deep learning models were developed using clinical values [vital signs, shock index-pediatric adjusted (SIPA), organ injured, and blood products received], laboratory results [hemoglobin, base deficit, INR, lactate, thromboelastography (TEG)], and imaging findings [focused assessment with sonography in trauma (FAST) and grade of injury on computed tomography scan] from pre-hospital to ED settings for prediction of MT, failure of NOM, mortality, and successful NOM without intervention. Sensitivity, specificity, accuracy, and area under the receiver operating characteristic curve (AUC) were used to evaluate each model's performance.ResultsA total of 477 patients were included, of which 5.7% required MT (27/477), 7.2% failed NOM (34/477), 4.4% died (21/477), and 89.1% had successful NOM (425/477). The accuracy of the models in the validation set was as follows: MT (90.5%), failure of NOM (83.8%), mortality (91.9%), and successful NOM without intervention (90.3%). Serial vital signs, the grade of organ injury, hemoglobin, and positive FAST had low correlations with outcomes.ConclusionDeep learning-based models using a combination of clinical, laboratory and radiographic features can predict the need for emergent intervention (MT, angioembolization, or operative management) and mortality with high accuracy and sensitivity using data available in the first 4 hours of admission. Further research is needed to externally validate and determine the feasibility of prospectively applying this framework to improve care and outcomes.Level of EvidenceIIIStudy TypeRetrospective comparative study (Prognosis/Care Management).  相似文献   
103.
Although interest in the role of donor-specific antibodies (DSAs) in kidney transplant rejection, graft survival, and histopathological outcomes is increasing, their impact on steroid avoidance or minimization in renal transplant populations is poorly understood. Primary outcomes of graft survival, rejection, and histopathological findings were assessed in 188 patients who received transplants between 2012 and 2015 at the Scripps Center for Organ Transplantation, which follows a steroid avoidance protocol. Analyses were performed using data from the United Network for Organ Sharing. Cohorts included kidney transplant recipients with de novo DSAs (dnDSAs; n = 27), preformed DSAs (pfDSAs; n = 15), and no DSAs (nDSAs; n = 146). Median time to dnDSA development (classes I and II) was shorter (102 days) than in previous studies. Rejection of any type was associated with DSAs to class I HLA (P < .05) and class II HLA (P < .01) but not with graft loss. Although mean fluorescence intensity (MFI) independently showed no association with rejection, an MFI >5000 showed a trend toward more antibody-mediated rejection (P < .06), though graft loss was not independently associated. Banff chronic allograft nephropathy scores and a modified chronic injury score were increased in the dnDSA cohort at 6 months, but not at 2 years (P < .001 and P < .08, respectively). Our data suggest that dnDSAs and pfDSAs impact short-term rejection rates but do not negatively impact graft survival or histopathological outcomes at 2 years. Periodic protocol post-transplant DSA monitoring may preemptively identify patients who develop dnDSAs who are at a higher risk for rejection.  相似文献   
104.
105.
Total ankle arthroplasty (TAA) is used as an alternative to ankle arthrodesis for adults with severe ankle arthritis. Numerous orthopedic centers have entered the healthcare market offering fast-tracked joint replacement protocols, meanwhile, TAA has been excluded from these joint centers, and is primarily performed in the inpatient setting. The purpose of this study is to examine short-term complications in the inpatient and outpatient settings following TAA using a systematic review and quantitative analysis. We considered all studies examining short-term complications following TAA performed in the inpatient versus outpatient setting occuring within 1 year of the index operation. We summarized data using a pooled relative risk and random effects model. A pooled sensitivity analysis was performed for studies with data on complication rates for inpatient or outpatient populations, which did not have a control group. The quality of included studies was assessed using the Cochrane risk of bias tool. Nine studies were included in the quantitative analysis, with 4 studies in the final meta-analysis. Subjects undergoing inpatient surgery experienced a 5-times higher risk of short-term complications compared to the outpatient group (risk ratio 5.27, 95% confidence interval 3.31, 8.42). Results did not change after sensitivity analysis (inpatient weighted mean complication rate: 9.62% vs outpatient weighted mean 5.02%, p value <.001). The overall level of evidence of included studies was level III, with a moderate to high risk of bias. Outpatient TAAs do not appear to pose excess complication risks compared to inpatient procedures, and may therefore be a reasonable addition to experienced centers that have established a fast-track outpatient total joint protocol.  相似文献   
106.
107.
108.
Context: The purpose of this report is to describe the clinical decision-making process for a patient with rheumatoid arthritis with neck pain with underlying atlantoaxial instability.Findings: The patient was evaluated for worsening upper neck pain that began insidiously 1 year prior. The patient denied numbness or tingling in her upper or lower extremities, dizziness or lightheadedness, difficulty maintaining balance with walking, or muscle weakness. Cervical spine range of motion was limited in all planes due to pain and apprehension. The patient’s neurological examination was unremarkable. Prior flexion and extension radiographs of the cervical spine were interpreted as unremarkable with alignment preserved in flexion and extension. However, upon further inspection, the cervical spine flexion radiograph was concerning for inadequate cervical motion, which may have limited the diagnostic utility of these radiographs. Additionally, a Sharp-Purser test was performed, which was positive for excessive motion. Flexion and extension radiographs of the cervical spine were then repeated ensuring the patient adequately flexed and extended during the imaging. Severe anterior subluxation of C1 relative to C2 with cervical flexion was noted, as C1 moved as much as 8–9 mm anterior to C2 with cervical flexion. Given the degree of atlantoaxial instability, the patient subsequently underwent successful posterior fusion from the occiput to C2.Conclusion/Clinical Relevance: This case report demonstrates the importance of properly screening for upper cervical spine instability in patients with rheumatoid arthritis and neck pain and understanding the importance of obtaining adequate and appropriate diagnostic imaging.  相似文献   
109.

Because the public health response to the disproportionate HIV burden faced by Black sexual minority men (BSMMM) has focused on sexual risk reduction and disease prevention, other vital components of sexual health (e.g., intimacy, pleasure, benefits of sex) have been often overlooked. Sex-positive describes a more open, holistic approach toward sex and sexuality that prioritizes these other components, though such an approach is rarely applied to BSMM's sexual health. For sex-positive BSMM, risk/preventive discourse may foster or exacerbate medical mistrust as a reaction to the dissonance between how these men view sexual health and how the medical establishment views it, which may discourage sexual healthcare-seeking. We assessed sex-positivity and its association with medical mistrust and PrEP conspiracy beliefs among 206 HIV-negative cisgender BSMM in Atlanta, Georgia. We performed exploratory factor analytic procedures on responses to a sex-positivity scale, followed by multivariable linear regressions to determine sex-positivity’s associations with medical mistrust and PrEP conspiracy beliefs. We extracted two sex-positivity factors: sexual freedom (α?=?0.90), reflecting openness toward casual sex and rejection of sexual mores, and essence of sex (α?=?0.77), reflecting the intimate, relational, and pleasurable qualities of sex. Sexual freedom was independently associated with perceived provider deception (β?=?0.19, CI?=?0.04, 0.34). Essence of sex was independently associated with PrEP conspiracy beliefs (β?=?0.16, CI?=?0.02, 0.31) and marginally associated with perceived provider deception (β?=?0.14, CI?=???0.00, 0.29). Healthcare providers and public health practitioners may cultivate greater trust with BSMM by incorporating a sex-positive approach into patient/participant interactions, clinical decision-making, and interventions. Improving access to sexual pleasure acknowledges BSMM’s right to optimal, holistic sexual health.

  相似文献   
110.
Journal of Community Health - While human papilloma virus (HPV) vaccinations and Pap smear screenings are known to improve the survival rates and incidence of cervical cancer, refugee populations...  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