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   23664篇
  免费   1662篇
  国内免费   56篇
耳鼻咽喉   309篇
儿科学   455篇
妇产科学   509篇
基础医学   3055篇
口腔科学   375篇
临床医学   2807篇
内科学   4696篇
皮肤病学   338篇
神经病学   2029篇
特种医学   897篇
外科学   4191篇
综合类   185篇
一般理论   50篇
预防医学   1737篇
眼科学   587篇
药学   1554篇
中国医学   21篇
肿瘤学   1587篇
  2024年   27篇
  2023年   254篇
  2022年   426篇
  2021年   1019篇
  2020年   509篇
  2019年   870篇
  2018年   941篇
  2017年   681篇
  2016年   726篇
  2015年   823篇
  2014年   1222篇
  2013年   1364篇
  2012年   2239篇
  2011年   2263篇
  2010年   1168篇
  2009年   1076篇
  2008年   1638篇
  2007年   1611篇
  2006年   1441篇
  2005年   1339篇
  2004年   1137篇
  2003年   1003篇
  2002年   830篇
  2001年   113篇
  2000年   76篇
  1999年   66篇
  1998年   106篇
  1997年   74篇
  1996年   43篇
  1995年   27篇
  1994年   32篇
  1993年   24篇
  1992年   17篇
  1991年   15篇
  1990年   9篇
  1989年   19篇
  1988年   16篇
  1987年   8篇
  1986年   13篇
  1985年   16篇
  1984年   11篇
  1983年   13篇
  1982年   9篇
  1981年   7篇
  1980年   10篇
  1979年   9篇
  1978年   5篇
  1971年   3篇
  1968年   3篇
  1966年   3篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
82.
83.
BackgroundRevision total knee arthroplasty (rTKA) rates are increasing in younger patients. Few studies have assessed outcomes of initial aseptic rTKA performed for younger patients compared with traditional-aged patients.MethodsA detailed medical record review was performed to identify patient demographics, medical comorbidities, surgical rTKA indications, timing from index TKA to rTKA, subsequent reoperation rates, component rerevision rates, and salvage procedures for 147 young patients (158 knees) aged 55 years and younger and for a traditional older cohort of 276 patients (300 knees) between 60 and 75 years. Univariate analysis was performed to assess differences in these primary variables, and a log-rank test was used to estimate 5-year implant survival based on either reoperation or component revision and salvage procedures.ResultsYounger TKA patients were more likely to undergo initial aseptic rTKA within 2 years of their primary TKA (52.5% vs 29.0%, P < .001) and were more likely to undergo early reoperation (17.7% vs 9.7%, P = .02) or component rerevision (11.4% vs 6.0%, P < .05) after rTKA. Infection and extensor mechanism complications were more commonly noted in younger patients. Estimated 5-year survival was also lower for both reoperation (59.4% vs 65.7%, P = .02) and component rerevision or salvage (65.8% vs 80.1%, P = .02).ConclusionEarly reoperation and component re-rTKA were performed nearly twice as often in younger rTKA than traditional-aged TKA patients. Care should be given to reduce perioperative infection and extensor mechanism failures after rTKA in younger patients.  相似文献   
84.
Major osteoporotic fractures (MOFs) are associated with a rapid decline in health-related quality of life (HRQoL); however, there is limited knowledge about which healthcare services positively affect HRQoL postfracture. This study aimed to identify specific combinations of health service use associated with recovery of HRQoL 12 months post-MOF. The analyses included 4126 adults aged ≥50 years with an MOF (1657 hip, 1354 distal forearm, 681 vertebrae, 434 humerus) participating in the International Costs and Utilities Related to Osteoporotic fractures Study (ICUROS), a multinational observational study (Australia, Austria, Estonia, France, Italy, Lithuania, Mexico, Russia, Spain, United Kingdom, and United States). HRQoL at prefracture and 12 months postfracture was measured using the EuroQoL questionnaire (EQ-5D-3L). Health service use data were collected via participant interviews and medical record reviews including in-hospital care; outpatient care; community services; and medication use. Data analyses involved two stages: (i) latent class analyses to identify different combinations of health service use (“classes”); and (ii) logistic regression to assess effects of classes on HRQoL recovery. Analyses were repeated excluding hip fractures (non-hip MOFs). Overall, 2057 MOF participants (49.9%) recovered to their prefracture HRQoL at 12-month follow-up; this proportion was higher for non-hip MOFs (n = 1439; 58.3%). Several distinct classes were identified across countries (range, 2–5 classes). Classes that were associated with increased odds of HRQoL recovery were characterized by a combination of hospital presentations without admission; outpatient department visits; allied health visits; vitamin D/calcium supplementation; and/or non-opioid analgesic use. Similar classes were observed for non-hip MOFs. Understanding country-specific healthcare service pathways that influence greater recovery of HRQoL, particularly services that are uncommon in some countries and routine in others, could improve postfracture care on a global scale. © 2020 American Society for Bone and Mineral Research (ASBMR).  相似文献   
85.
Modifications to the constituents of the gut microbiome influence bone density and tissue-level strength, but the specific microbial components that influence tissue-level strength in bone are not known. Here, we selectively modify constituents of the gut microbiota using narrow-spectrum antibiotics to identify components of the microbiome associated with changes in bone mechanical and material properties. Male C57BL/6J mice (4 weeks) were divided into seven groups (n = 7–10/group) and had taxa within the gut microbiome removed through dosing with: (i) ampicillin; (ii) neomycin; (iii) vancomycin; (iv) metronidazole; (v) a cocktail of all four antibiotics together (with zero-calorie sweetener to ensure intake); (vi) zero-calorie sweetener only; or (vii) no additive (untreated) for 12 weeks. Individual antibiotics remove only some taxa from the gut, while the cocktail of all four removes almost all microbes. After accounting for differences in geometry, whole bone strength was reduced in animals with gut microbiome modified by neomycin (−28%, p = 0.002) and was increased in the group in which the gut microbiome was altered by sweetener alone (+39%, p < 0.001). Analysis of the fecal microbiota detected seven lower-ranked taxa differentially abundant in animals with impaired tissue-level strength and 14 differentially abundant taxa associated with increased tissue-level strength. Histological and serum markers of bone turnover and trabecular bone volume per tissue volume (BV/TV) did not differ among groups. These findings demonstrate that modifications to the taxonomic components of the gut microbiome have the potential to decrease or increase tissue-level strength of bone independent of bone quantity and without noticeable changes in bone turnover. © 2021 American Society for Bone and Mineral Research (ASBMR).  相似文献   
86.
BackgroundCurrent data regarding the risk of malignancy in a large thyroid nodule with benign fine-needle aspiration biopsy(FNAB) is conflicting. We investigated the impact of patient age on the risk of malignancy in nodules≥4 cm with benign cytology.MethodsWe performed a single-institution retrospective review of patients who underwent surgery from 07/2008–08/2019 for a cytologically benign thyroid nodule ≥4 cm. The relationship between malignant histopathology and patient and ultrasound features was assessed with multivariable logistic regression.ResultsOf 474 nodules identified, 25(5.3%) were malignant on final pathology. In patients <55 years old, 21/273(7.7%) nodules were malignant, compared to 4/201(2.0%) in patients ≥55. Patient age ≥55 was independently associated with significantly lower risk of malignancy(OR:0.2,95%CI:0.1–0.7,p = 0.011). Increasing nodule size >4 cm and high-risk ultrasound features were not associated with risk of malignancy(OR:1.0,95%CI:0.7–1.4,p = 0.980, and OR:9.6,95%CI:0.9–107.8,p = 0.066, respectively).ConclusionsPatients <55 years old are 3.7-fold more likely to have a falsely benign FNA biopsy in a nodule≥4 cm.  相似文献   
87.
BackgroundSuccessful trauma resuscitation relies on multi-disciplinary collaboration. In most academic programs, general surgery (GS) and emergency medicine (EM) residents rarely train together before functioning as a team.MethodsIn our Multi-Disciplinary Trauma Evaluation and Management Simulation (MD-TEAMS), EM and GS residents completed manikin-based trauma scenarios and were evaluated on resuscitation and communication skills. Residents were surveyed on confidence surrounding training objectives.ResultsResidents showed improved confidence running trauma scenarios in multi-disciplinary teams. Residents received lower communication scores from same-discipline vs cross-discipline faculty. EM residents scored higher in evaluation and planning domains; GS residents scored higher in action processes; groups scored equally in team management. Strong correlation existed between team leader communication and resuscitative skill completion.ConclusionMD-TEAMS demonstrated correlation between communication and resuscitation checklist item completion and communication differences by resident specialty. In the future, we plan to evaluate training-related resident behavior changes and specialty-specific communication differences by residents.  相似文献   
88.
89.
The prevalence of type 2 diabetes in youth has increased substantially, yet the genetic underpinnings remain largely unexplored. To identify genetic variants predisposing to youth-onset type 2 diabetes, we formed ProDiGY, a multiethnic collaboration of three studies (TODAY, SEARCH, and T2D-GENES) with 3,006 youth case subjects with type 2 diabetes (mean age 15.1 ± 2.9 years) and 6,061 diabetes-free adult control subjects (mean age 54.2 ± 12.4 years). After stratifying by principal component–clustered ethnicity, we performed association analyses on ∼10 million imputed variants using a generalized linear mixed model incorporating a genetic relationship matrix to account for population structure and adjusting for sex. We identified seven genome-wide significant loci, including the novel locus rs10992863 in PHF2 (P = 3.2 × 10−8; odds ratio [OR] = 1.23). Known loci identified in our analysis include rs7903146 in TCF7L2 (P = 8.0 × 10−20; OR 1.58), rs72982988 near MC4R (P = 4.4 × 10−14; OR 1.53), rs200893788 in CDC123 (P = 1.1 × 10−12; OR 1.32), rs2237892 in KCNQ1 (P = 4.8 × 10−11; OR 1.59), rs937589119 in IGF2BP2 (P = 3.1 × 10−9; OR 1.34), and rs113748381 in SLC16A11 (P = 4.1 × 10−8; OR 1.04). Secondary analysis with 856 diabetes-free youth control subjects uncovered an additional locus in CPEB2 (P = 3.2 × 10−8; OR 2.1) and consistent direction of effect for diabetes risk. In conclusion, we identified both known and novel loci in the first genome-wide association study of youth-onset type 2 diabetes.  相似文献   
90.
IntroductionThere are many described technique to performing laparoscopic inguinal hernia repair in children. We describe our outcomes using a percutaneous internal ring suturing technique.MethodsA retrospective review of patients under 18 years old who underwent repair between January 2014 - March 2019 was performed. A percutaneous internal ring suturing technique, involving hydro-dissection of the peritoneum, percutaneous suture passage, and cauterization of the peritoneum in the sac prior to high ligation, was used. p < 0.05 was considered significant during the analysis.Results791 patients were included. The median age at operation was 1.9 years (IQR 0.37, 5.82). The median operative time for a unilateral repair was 21 min (IQR 16, 28), while the median time for a bilateral repair was 30.5 min (IQR 23, 41).In total, 3 patients required conversion to an open procedure (0.4%), 4 (0.6%) experienced post-operative bleeding, 9 (1.2%) developed a wound infection, and iatrogenic ascent of testis occurred in 10 (1.3%) patients. Twenty patients (2.5%) developed a recurrent hernia. All but two were re-repaired laparoscopically.ConclusionsThe use of percutaneous internal ring suturing for laparoscopic repair of inguinal hernias in the pediatric population is safe and effective with a low rate of complications and recurrence.  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