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   13499篇
  免费   1121篇
  国内免费   25篇
耳鼻咽喉   187篇
儿科学   533篇
妇产科学   376篇
基础医学   1648篇
口腔科学   115篇
临床医学   1512篇
内科学   2414篇
皮肤病学   254篇
神经病学   1548篇
特种医学   293篇
外科学   1487篇
综合类   86篇
一般理论   20篇
预防医学   2100篇
眼科学   324篇
药学   807篇
  1篇
中国医学   15篇
肿瘤学   925篇
  2024年   47篇
  2023年   315篇
  2022年   474篇
  2021年   927篇
  2020年   535篇
  2019年   788篇
  2018年   853篇
  2017年   571篇
  2016年   589篇
  2015年   569篇
  2014年   713篇
  2013年   865篇
  2012年   1255篇
  2011年   1223篇
  2010年   588篇
  2009年   480篇
  2008年   774篇
  2007年   710篇
  2006年   545篇
  2005年   495篇
  2004年   402篇
  2003年   327篇
  2002年   251篇
  2001年   34篇
  2000年   23篇
  1999年   22篇
  1998年   38篇
  1997年   26篇
  1996年   17篇
  1995年   20篇
  1994年   17篇
  1993年   18篇
  1992年   8篇
  1991年   9篇
  1990年   6篇
  1989年   7篇
  1987年   3篇
  1986年   3篇
  1985年   5篇
  1984年   6篇
  1983年   8篇
  1982年   13篇
  1981年   7篇
  1980年   8篇
  1979年   3篇
  1978年   7篇
  1976年   5篇
  1973年   3篇
  1972年   3篇
  1924年   2篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
BackgroundAccurate resuscitation of pediatric patients with large thermal injury is critical to achieving optimal outcomes. The goal of this project was to describe the degree of variability in resuscitation guidelines among pediatric burn centers and the impact on fluid estimates.MethodsFive pediatric burn centers in the Pediatric Injury Quality Improvement Collaborative (PIQIC) contributed data from patients with ≥15% total body surface area (TBSA) burns treated from 2014 to 2018. Each center's resuscitation guidelines and guidelines from the American Burn Association were used to calculate estimated 24-h fluid requirements and compare these values to the actual fluid received.ResultsDifferences in the TBSA burn at which fluid resuscitation was initiated, coefficients related to the Parkland formula, criteria to initiate dextrose containing fluids, and urine output goals were observed. Three of the five centers’ resuscitation guidelines produced statistically significant lower mean fluid estimates when compared with the actual mean fluid received for all patients across centers (4.53 versus 6.35 ml/kg/% TBSA, p < 0.001), (4.90 versus 6.35 ml/kg/TBSA, p = 0.002) and (3.38 versus 6.35 ml/kg/TBSA, p < 0.0001).ConclusionsThis variation in practice patterns led to statistically significant differences in fluid estimates. One center chose to modify its resuscitation guidelines at the conclusion of this study.  相似文献   
72.
73.
BackgroundIn counseling patients about the complications of revision total hip arthroplasty (revTHA), it is imperative that mortality be considered. The actual mortality rate by indication of revision is ill-defined. The purpose of this study is to determine the mortality rate after revTHA.MethodsAn institutional database identified 596 patients who had undergone revTHA between 2012 and 2018. Medical records, national, state, and local death indexes were queried for mortality status and indication for revTHA. For survivors, the last clinical visit date was used for censoring in the mortality analysis. Mortality rates were calculated for all clinical patients and then by specific indication for revision.ResultsThe overall 2-year mortality rate following revTHA was 19.5 deaths per 1000 or 1 in 51 patients. Patients presenting with a periprosthetic fracture had a significantly higher 2-year mortality rate of 74.5 deaths per 1000 or 1 in 13 patients (P < .001), while an indication of dislocation or instability had a slightly higher 2-year mortality rate of 50.3 per 1000 (1 in 20) but this difference was not significant (P = .531). Other indications such as mechanical loosening or infection did not have a significantly different mortality rate.ConclusionThe overall 2-year mortality rate following revTHA was 19.5 deaths per 1000 which was largely attributed to patients with a periprosthetic fracture (74.5 per 1000) with other indications not significantly impacting mortality. Mortality rates and specific rates by indication for revision should be considered when counseling patients prior to revTHA.  相似文献   
74.
Background/purposeThough evidence-based clinical pathways for the diagnosis and treatment of pediatric appendicitis have been established, protocols guiding management of percutaneous abscess drains are lacking. We hypothesized a drain management protocol utilizing drain output and clinical factors instead of fluoroscopic drain studies would reduce interventional radiologic procedures without adversely impacting clinical outcomes.MethodsA standardized protocol was uniformly adopted at a tertiary-care children's hospital in April 2016. A retrospective chart review included all cases of appendicitis requiring abscess drainage by interventional radiology three years pre- and postprotocol implementation.ResultsFifty-eight patients (preprotocol = 39, postprotocol = 19) underwent percutaneous abscess drainage, of whom 52 (preprotocol = 34, postprotocol = 18) required a drain. Baseline demographics and clinical presentation were similar across groups. Following protocol implementation, total number of IR procedures decreased from 2.4 to 1.3 per patient (p = 0.004). There was no significant difference in the number of postprocedure diagnostic imaging studies, readmissions, or inpatient days, and there was a trend towards a decrease in number of drain days (10.7 to 5.7, p = 0.067).ConclusionA standardized protocol for management of abscess drains for complicated appendicitis reduced the number of IR procedures without a negative impact on clinical outcomes or increase in alternative imaging studies. This approach may decrease radiation exposure, anesthetic administration, and resource utilization.Type of studyTreatment study (retrospective comparative study).Level of evidenceLevel III.  相似文献   
75.
Skeletal muscle has remarkable regenerative ability after injury. Mesenchymal fibro-adipogenic progenitors (FAPs) are necessary, active participants during this repair process, but the molecular signatures of these cells and their functional relevance remain largely unexplored. Here, using a lineage tracing mouse model (Gli1-CreER Tomato), we demonstrate that Gli1 marks a small subset of muscle-resident FAPs with elevated Hedgehog (Hh) signaling. Upon notexin muscle injury, these cells preferentially and rapidly expanded within FAPs. Ablation of Gli1+ cells using a DTA mouse model drastically reduced fibroblastic colony-forming unit (CFU-F) colonies generated by muscle cells and impaired muscle repair at 28 days. Pharmacologic manipulation revealed that Gli1+ FAPs rely on Hh signaling to increase the size of regenerating myofiber. Sorted Gli1+ FAPs displayed superior clonogenicity and reduced adipogenic differentiation ability in culture compared to sorted Gli1− FAPs. In a glycerol injury model, Gli1+ FAPs were less likely to give rise to muscle adipocytes compared to other FAPs. Further cell ablation and Hh activator/inhibitor treatments demonstrated their dual actions in enhancing myogenesis and reducing adipogenesis after injury. Examining single-cell RNA-sequencing dataset of FAPs from normal mice indicated that Gli1+ FAPs with increased Hh signaling provide trophic signals to myogenic cells while restrict their own adipogenic differentiation. Collectively, our findings identified a subpopulation of FAPs that play an essential role in skeletal muscle repair. © 2021 American Society for Bone and Mineral Research (ASBMR).  相似文献   
76.
Bone metastasis is a complication of prostate cancer in up to 90% of men afflicted with advanced disease. Therapies that reduce androgen exposure remain at the forefront of treatment. However, most prostate cancers transition to a state whereby reducing testicular androgen action becomes ineffective. A common mechanism of this transition is intratumoral production of testosterone (T) using the adrenal androgen precursor dehydroepiandrosterone (DHEA) through enzymatic conversion by 3β- and 17β-hydroxysteroid dehydrogenases (3βHSD and 17βHSD). Given the ability of prostate cancer to form blastic metastases in bone, we hypothesized that osteoblasts might be a source of androgen synthesis. RNA expression analyses of murine osteoblasts and human bone confirmed that at least one 3βHSD and 17βHSD enzyme isoform was expressed, suggesting that osteoblasts are capable of generating androgens from adrenal DHEA. Murine osteoblasts were treated with 100 nM and 1 μM DHEA or vehicle control. Conditioned media from these osteoblasts were assayed for intermediate and active androgens by liquid chromatography–tandem mass spectrometry. As DHEA was consumed, the androgen intermediates androstenediol and androstenedione were generated and subsequently converted to T. Conditioned media of DHEA-treated osteoblasts increased androgen receptor (AR) signaling, prostate-specific antigen (PSA) production, and cell numbers of the androgen-sensitive prostate cancer cell lines C4-2B and LNCaP. DHEA did not induce AR signaling in osteoblasts despite AR expression in this cell type. We describe an unreported function of osteoblasts as a source of T that is especially relevant during androgen-responsive metastatic prostate cancer invasion into bone. © 2021 American Society for Bone and Mineral Research (ASBMR). This article has been contributed to by US Government employees and their work is in the public domain in the USA.  相似文献   
77.
Annals of Surgical Oncology - Black women with breast cancer have a worse overall survival compared with White women; however, no difference in Oncotype DX? (ODX) recurrence scores has been...  相似文献   
78.
BackgroundPreoperative carbohydrate loading is a component of Enhanced Recovery After Surgery (ERAS) protocols, but there is limited literature in bariatric surgery patients.ObjectivesThe objective of this study was to characterize the impact of preoperative carbohydrate loading on postoperative bariatric surgery outcomes.SettingUniversity Hospital.MethodsPatients undergoing a primary minimally invasive Roux-en-Y gastric bypass (RYGB) or sleeve gastrectomy (SG) between 2018 and 2020 were randomized to standard management or intervention. Standard management patients were nothing by mouth (NPO) after midnight prior to surgery. Intervention patients consumed 2 carbohydrate drinks: 1 the night before and another 3 hours prior to surgery. Primary outcomes analyzed included postoperative nausea and vomiting (PONV), length of stay, and overall complications.ResultsIn total, 134 patients were analyzed: 64 intervention (47.8%) and 70 (52.2%) standard. In the end, 7% and 15% of patients were lost to follow-up at 6-weeks and 3-months, respectively. There was no statistically significant difference in length of stay (2.0 ± 1.2 vs 2.1 ± .9 d; P = .65) or postoperative outcomes between the 2 groups. There were no episodes of aspiration among the intervention group. Among RYGB patients, intervention patients had a shorter duration of nausea compared with standard patients. There was no significant difference in glycemic control among patients with and without diabetes.ConclusionsPreoperative carbohydrate drinks can be administered to bariatric surgery patients without significant risks. Carbohydrate loading preoperatively can decrease the duration of PONV in RYGB patients. Carbohydrate drinks can be safely included in bariatric ERAS protocols for patients with and without diabetes, although the benefits remain unknown.  相似文献   
79.
Background: Hand and distal forearm allotransplantation has advanced over the last 20 years from experimental to a viable treatment option for bilateral upper extremity amputation. Despite widespread growth of this field, there are few technical reports that elaborate the details of donor arm procurement. This article details a technique for rapid donor procurement through the elbow for mid to distal forearm-level hand allograft procurement. Methods: Nine arm procurements were performed on deceased tissue-only donors provided by the local organ procurement organization, including two bilateral and five unilateral cases. Technique highlights include using a fishmouth incision through the lateral and medical epicondyles, identification of the neurovascular structures, and disarticulating the elbow joint. Results: Procuring through the elbow provides straightforward anatomy, bypasses the need to cut through bone, and allows tissue allotransplantation teams to achieve procurement, flushing, and packaging within 20 minutes. Conclusions: Procurement through the elbow is a simple procedure that streamlines the process for multi-organ donors by minimizing the time needed for hand allograft procurement. Team coordination and surgical rehearsals are essential for successful hand and upper extremity procurement and allotransplantation.  相似文献   
80.
BackgroundTezacaftor (TEZ)/ivacaftor (IVA) is an approved CFTR modulator shown to be efficacious and generally safe and well tolerated in people ≥12 years of age with cystic fibrosis (CF) homozygous for the F508del-CFTR mutation or heterozygous for the F508del-CFTR mutation and a residual function mutation. Although previous studies with IVA alone showed clinical benefits in people with CFTR gating mutations, TEZ/IVA has not yet been evaluated in a Phase 3 study of participants heterozygous for F508del-CFTR and a gating mutation (F/gating genotypes). Here, we present results from a randomized, double-blind, IVA-controlled, parallel-group, Phase 3 study assessing the efficacy, safety, and pharmacokinetics (PK) of TEZ/IVA in participants ≥12 years of age with F/gating genotypes.MethodsEnrolled participants entered a 4-week IVA run-in period to create a stable IVA baseline. Participants were then randomized to receive IVA or TEZ/IVA for 8 weeks in an active comparator treatment period (ACTP). The primary endpoint was absolute change in percent predicted forced expiratory volume in 1 second (ppFEV1). Key secondary endpoints were relative change in ppFEV1 and absolute change in CF Questionnaire–Revised respiratory domain score. Secondary endpoints included absolute change in sweat chloride (SwCl) concentration, PK parameters, and safety. All endpoints except PK parameters and safety were assessed from baseline through Week 8.ResultsSixty-nine participants (92.0%) in the IVA group and 75 participants (98.7%) in the TEZ/IVA group completed treatment. No improvements were seen in efficacy endpoints from baseline at the end of the IVA run-in period through the end of the ACTP in the IVA group. No significant differences in ppFEV1 or any key secondary endpoint were observed between the IVA and TEZ/IVA groups. SwCl concentrations decreased more in the TEZ/IVA versus IVA group during the ACTP. The safety profile and PK parameters of TEZ/IVA were consistent with those of previous studies in participants ≥12 years of age with CF.ConclusionsThis Phase 3 study showed that the dual-combination regimen of TEZ/IVA demonstrated clinical efficacy but did not have significantly greater clinical efficacy than IVA alone in participants ≥12 years of age with F/gating genotypes. However, as reported in other studies, TEZ/IVA was generally safe and well tolerated (NCT02412111).  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