全文获取类型
收费全文 | 228518篇 |
免费 | 5343篇 |
国内免费 | 1705篇 |
专业分类
耳鼻咽喉 | 1635篇 |
儿科学 | 7703篇 |
妇产科学 | 4110篇 |
基础医学 | 22258篇 |
口腔科学 | 2639篇 |
临床医学 | 18402篇 |
内科学 | 41227篇 |
皮肤病学 | 1722篇 |
神经病学 | 19453篇 |
特种医学 | 10066篇 |
外国民族医学 | 6篇 |
外科学 | 34636篇 |
综合类 | 8411篇 |
现状与发展 | 2篇 |
一般理论 | 9篇 |
预防医学 | 22711篇 |
眼科学 | 3988篇 |
药学 | 14312篇 |
53篇 | |
中国医学 | 2928篇 |
肿瘤学 | 19295篇 |
出版年
2024年 | 168篇 |
2023年 | 714篇 |
2022年 | 1697篇 |
2021年 | 2693篇 |
2020年 | 1914篇 |
2019年 | 1836篇 |
2018年 | 23736篇 |
2017年 | 18983篇 |
2016年 | 20845篇 |
2015年 | 3062篇 |
2014年 | 3659篇 |
2013年 | 4092篇 |
2012年 | 11847篇 |
2011年 | 25838篇 |
2010年 | 22056篇 |
2009年 | 14355篇 |
2008年 | 22886篇 |
2007年 | 25024篇 |
2006年 | 3523篇 |
2005年 | 4872篇 |
2004年 | 5455篇 |
2003年 | 6294篇 |
2002年 | 4079篇 |
2001年 | 712篇 |
2000年 | 765篇 |
1999年 | 470篇 |
1998年 | 471篇 |
1997年 | 451篇 |
1996年 | 310篇 |
1995年 | 276篇 |
1994年 | 241篇 |
1993年 | 173篇 |
1992年 | 140篇 |
1991年 | 156篇 |
1990年 | 200篇 |
1989年 | 143篇 |
1988年 | 112篇 |
1987年 | 90篇 |
1986年 | 75篇 |
1985年 | 78篇 |
1984年 | 65篇 |
1983年 | 62篇 |
1982年 | 82篇 |
1981年 | 66篇 |
1980年 | 75篇 |
1979年 | 42篇 |
1976年 | 39篇 |
1938年 | 60篇 |
1932年 | 56篇 |
1930年 | 48篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
991.
Alessandro Aprato Alexander Joeris Ferdinando Tosto Vasiliki Kalampoki Elke Rometsch Marco Favuto Alessandro Stucchi Matheus Azi Alessandro Massè 《Journal of orthopaedics and traumatology》2016,17(2):169-173
Background
Resuming work after surgical treatment of an unstable pelvic ring injury is often impeded because of residual disability. The aim of this study was to test which factors influence return to work, ability to return to the same job function as before the injury, leaves of absence, and incapacitation after sustaining a pelvic fracture.Materials and methods
We performed a retrospective study on patients with surgically treated pelvic fractures. Medical records were reviewed to document patients’ demographic data, the extent of follow-up care, diagnosis of the injury (according to the Tile system of classification), type of surgical treatment, injury severity, and the time from trauma to definitive surgery. We also recorded the classification of patients’ physical status according to the American Society of Anesthesiologists (ASA) and details about admission to the intensive care unit (ICU). Patients were interviewed to note the number of days before returning to work and their ability to maintain their previously held jobs.Results
Fifty patients were included in the study, and their mean age was 46.3 ± 12.6 years. The median time to return to work was 195 days. Twelve patients (24 %) lost their jobs and 17 (34 %) resumed their previous job with a change of tasks. ICU admission and time from trauma to definitive surgery were negatively correlated with return to the previously held job. Returning to the same job tasks was not associated with any of the factors investigated. Polytrauma, ICU admission, and time from trauma to definitive surgery were associated with longer leaves of absence.Conclusions
Work reintegration after pelvic ring injuries is a major issue for patients and health care systems: 58 % of patients were not able to return to or lost their job. Factors correlated with leaves of absence were injury severity, delayed definitive fixation, and ICU admission.Level of evidence
IV (case series).992.
Kamrul Hasan Shivakumar Shankar Aadhar Sharma Alison Carter Razi Zaidi Suzie Cro John Skinner Andy Goldberg 《Journal of orthopaedics and traumatology》2016,17(4):291-295
Background
The burden of traumatic and elective hip surgery is set to grow. With an increasing number of techniques and implants against the background of an aging population, the emphasis on evidence-based treatment has never been greater. The purpose of this study was to assess changes in the levels of evidence in the hip literature over a decade.Materials and methods
Articles pertaining to hip surgery from the years 2000 and 2010 in Hip International, Journal of Arthroplasty, Journal of Bone and Joint Surgery and The Bone and Joint Journal were analysed. Articles were ranked by a five-point level of evidence scale and by type of study, according to guidelines from the Centre for Evidence-based Medicine.Results
531 articles were analysed from 48 countries. The kappa value for the inter-observer reliability showed excellent agreement between the reviewers for study type (κ = 0.956, P < 0.01) and for levels of evidence (κ = 0.772, P < 0.01). Between 2000 and 2010, the overall percentage of high-level evidence (levels I and II) studies more than doubled (12 to 31 %, P < 0.001). The most frequent study type was therapeutic; the USA and UK were the largest producers of published work in these journals, with contributions from other countries increasing markedly over the decade.Conclusions
There has been a significant increase in high levels of evidence in hip surgery over a decade (P < 0.001). We recommend that all orthopaedic journals consider implementing compulsory declaration by authors of the level of evidence to help enhance quality of evidence.Level of evidence
Level 2: economic and decision analysis.993.
Ekaterina Urch Samuel A. Taylor Elizabeth Cody Peter D. Fabricant Jayme C. Burket Stephen J. O’Brien David M. Dines Joshua S. Dines 《HSS journal》2016,12(3):209-215
Background
The internet has an increasing role in both patient and physician education. While several recent studies critically appraised the quality and accuracy of web-based written information available to patients, no studies have evaluated such parameters for open-access video content designed for provider use.Questions/Purposes
The primary goal of the study was to determine the accuracy of internet-based instructional videos featuring the shoulder physical examination.Methods
An assessment of quality and accuracy of said video content was performed using the basic shoulder examination as a surrogate for the “best-case scenario” due to its widely accepted components that are stable over time. Three search terms (“shoulder,” “examination,” and “shoulder exam”) were entered into the four online video resources most commonly accessed by orthopaedic surgery residents (VuMedi, G9MD, Orthobullets, and YouTube). Videos were captured and independently reviewed by three orthopaedic surgeons. Quality and accuracy were assessed in accordance with previously published standards.Results
Of the 39 video tutorials reviewed, 61% were rated as fair or poor. Specific maneuvers such as the Hawkins test, O’Brien sign, and Neer impingement test were accurately demonstrated in 50, 36, and 27% of videos, respectively. Inter-rater reliability was excellent (mean kappa 0.80, range 0.79–0.81).Conclusion
Our results suggest that information presented in open-access video tutorials featuring the physical examination of the shoulder is inconsistent. Trainee exposure to such potentially inaccurate information may have a significant impact on trainee education.994.
Dimitrios Karavias Ioannis Maroulis Helen Papadaki Charalambos Gogos Stavros Kakkos Dionissios Karavias Vasiliki Bravou 《Journal of gastrointestinal surgery》2016,20(3):568-579
Background
Genomic instability is a common feature in hepatocellular carcinoma. Deregulation of replication licensing factors has been shown to trigger DNA damage response contributing to genomic instability. Overexpression of DNA replication licensing factors chromatin licensing and DNA replication factor 1 (CDT1) and minichromosome maintenance complex component 7 (MCM7) has been previously reported in several human cancers. The aim of the present study was to evaluate the expression and prognostic significance of CDT1 and MCM7 in association with DNA damage response markers and p53 in patients with hepatocellular carcinoma.Methods
Expression of CDT1, MCM7, p-H2A histone family member X (H2AX), phospho-ataxia telangiectasia-mutated (ATM)/ataxia telangiectasia rad3-related (ATR) substrate, and p53 was evaluated by immunohistochemistry on formalin-fixed paraffin-embedded surgical specimens from 111 patients who underwent hepatectomy for hepatocellular carcinoma. Statistical analysis was performed to evaluate associations between the studied proteins, clinicopathological parameters, and patient survival.Results
CDT1 expression correlated with p-H2AX (p?=?0.038), while MCM7 correlated with p-H2AX and phospho-ATM/ATR substrate (p?<?0.001). Increased CDT1 expression was associated with higher tumor grade (p?=?0.006) and tumor-node-metastasis (TNM) stage (p?=?0.033). High CDT1 expression correlated significantly with reduced overall survival (60.8 and 26.5 % vs 82.8 and 53.0 %, for low CDT1 expression, at 2 and 5 years, respectively, p?=?0.012) and was identified by multivariate analysis as an independent predictor of poor overall survival (p?=?0.049).Conclusions
Overexpression of CDT1 and MCM7 in hepatocellular carcinoma correlates with DNA damage response, and CDT1 overexpression is a significant prognostic biomarker in hepatocellular carcinoma.995.
Jill K. Onesti Lawrence A. Shirley Neil D. Saunders Gail W. Davidson Mary E. Dillhoff Hooman Khabiri Gregory E. Guy Joshua D. Dowell Carl R Schmidt Manisha H. Shah Mark Bloomston 《Journal of gastrointestinal surgery》2016,20(3):580-586
Introduction
We hypothesized that an elevated preoperative alkaline phosphatase (AP) predicted worse outcomes for patients undergoing transarterial chemoembolization (TACE) for neuroendocrine tumor (NET) liver metastases.Methods
We reviewed all patients who underwent TACE for metastatic NET between 2009 and 2013. Survival was evaluated using preprocedure variables.Results
One hundred and nine patients underwent 210 TACE procedures. The average age was 57.7 years (range 20–78). Primary sites included pancreas (N?=?20), other gastrointestinal (N?=?52), lung (N?=?9), and unknown (N?=?28). The tumor was grade 1 in 68 (62 %), grade 2 in 21 (19 %), and grade 3 in 3 (3 %). Extrahepatic disease was present in 54 (50 %) and greater than 50 % hepatic tumor burden by imaging in 63 (58 %). Elevated bilirubin occurred in 8 (7 %), elevated AP in 22 (20 %), elevated ALT in 21 (19 %), and elevated AST in 41 (38 %). Univariate predictors included tumor grade (43 vs 27 vs 21 months, p?=?0.015), hepatic tumor burden (59 vs 37 months, p?=?0.009), and elevated AP (59 vs 23 months, p?<?0.001). On multivariate analysis, only elevated AP (p?=?0.001) predicted worse survival.Conclusions
Elevated AP prior to TACE for metastatic NET portends a worse survival outcome, even more so than tumor grade or extent of hepatic disease.996.
Uberto Fumagalli Riccardo Rosati Stefano De Pascale Matteo Porta Elisa Carlani Alessandra Pestalozza Alessandro Repici 《Journal of gastrointestinal surgery》2016,20(3):494-499
Aim
Surgical myotomy of the lower esophageal sphincter has a 5-year success rate of approximately 91 %. Peroral endoscopic myotomy can provide similar results for controlling dysphagia. Some patients experience either persistent or recurrent dysphagia after myotomy. We present here a retrospective analysis of our experience with redo myotomy for recurrent dysphagia in patients with achalasia.Methods
From March 1996 to February 2015, 234 myotomies for primary or recurrent achalasia were performed in our center. Fifteen patients (6.4 %) had had a previous myotomy and were undergoing surgical redo myotomy (n?=?9) or endoscopic redo myotomy (n?=?6) for recurrent symptoms.Results
Patients presented at a median of 10.4 months after previous myotomy. Median preoperative Eckardt score was 6. Among the nine patients undergoing surgical myotomy, three esophageal perforations occurred intraoperatively (all repaired immediately). Surgery lasted 111 and 62 min on average (median) in the surgical and peroral endoscopic myotomy (POEM) groups, respectively. No postoperative complications occurred in either group. Median postoperative stay was 3 and 2.5 days in the surgical and POEM groups, respectively. In the surgical group, Eckardt score was <3 for seven out of nine patients after a mean follow-up of 19 months; it was <3 for all six patients in the POEM group after a mean follow-up of 5 months.Conclusions
A redo myotomy should be considered in patients who underwent myotomy for achalasia and presenting with recurrent dysphagia. Preliminary results using POEM indicate that the technique can be safely used in patients who have undergone previous surgical myotomy.997.
Background
Optimal surgical treatment for small early rectal carcinoids is controversial. Large tumors (greater than 2 cm) and those with imaging evidence of lymph node metastasis are generally treated by low anterior resection (LAR) with total mesorectal excision (TME). We first observed and reported that midgut carcinoid with extensive mesenteric lymphadenopathy often develops alternated lymphatic drainage pathways. We hypothesize that rectal carcinoids have the same potential to develop alternated lymphatic pathways outside the mesorectal envelope, which allows tumor deposits to be missed by traditional TME.Methods
Twenty-two consecutive rectal carcinoid surgical patient charts were reviewed to determine if alternated lymphatic drainage occurred and resulted in extra-mesorectal metastasis. We attempted to identify any risk factor(s) that may lead to developing such alternated lymphatic drainage pathways.Results
Thirteen patients underwent initial LAR with TME (13/22, 59 %) and nine underwent a staged debulking for locoregional residual disease or regional/distant metastasis after previous resection (9/22, 41 %). Fourteen (14/22, 64 %) underwent radio-guided surgery in attempt to achieve a higher level of pelvic/distant metastatic disease detection and debulking. Six patients (6/22, 27 %) had obturator canal lymph node metastases confirmed histologically.Conclusions
Based on our study, at least 27 % of rectal carcinoid patients may have extra-mesorectal metastasis that would be missed by the traditional TME. Radio-guided surgery can identify and remove such metastasis. The effect of having such extra-mesorectal metastasis and its surgical removal on long-term survival has yet to be determined.998.
Jennifer L. Williams Brian E. Kadera Andrew H. Nguyen V. Raman Muthusamy Zev A. Wainberg O. Joe Hines Howard A. Reber Timothy R. Donahue 《Journal of gastrointestinal surgery》2016,20(7):1331-1342
Background
Compared to the widely adopted 2–4 months of pre-operative therapy for patients with borderline resectable (BR) or locally advanced (LA) pancreatic ductal adenocarcinoma (PDAC), our institution tends to administer a longer duration before considering surgical resection. Using this unique approach, the aim of this study was to determine pre-operative variables associated with survival.Methods
Records from patients with BR/LA PDAC who underwent attempt at surgical resection from 1992–2014 were reviewed.Results
After a median duration of 6 months of pre-operative treatment, 109 patients with BR/LA PDAC (BR 63, LA 46) were explored; 93 (85.3 %) underwent pancreatectomy. Those who received at least 6 months of pre-operative treatment had longer median overall survival (OS) than those who received less (52.8 vs. 32.1 months, P?=?0.044). On multivariate analysis, pre-operative treatment duration was the strongest predictor of survival (hazard ratio (HR) 4.79, P?=?0.043). However, OS was similar in those whose CA19-9 normalized regardless of whether they received more or less than 6 months of chemotherapy (71.4 vs. 101.8 months, P?=?0.930).Conclusions
Pre-operative CA19-9 decline can guide treatment duration in patients with BR/LA PDAC. We endorse 6 months of therapy except in those patients whose values normalize, where surgery can be considered after a shorter course.999.
Ingrid Volløyhaug Siv Mørkved Kjell Å. Salvesen 《International urogynecology journal》2016,27(1):39-45
Introduction and hypothesis
It is known that pelvic floor muscle trauma (PFMT) after vaginal delivery is associated with pelvic organ prolapse (POP) symptoms (sPOP) and signs (POP-Q ≥2) in patient populations. Our aims were to establish the prevalence and investigate a possible association between PFMT and sPOP and POP-Q ≥2 in healthy women 20 years after their first delivery.Methods
During 2013 and 2014 we conducted a cross-sectional study among 847 women who delivered their first child between 1990 and 1997. Women responded to a postal questionnaire and were offered a clinical examination including prolapse grading and pelvic floor ultrasonography. The main outcome measures were sPOP, POP-Q ≥2 and PFMT, defined by levator avulsion or a levator hiatal area on Valsalva manoeuvre of >40 cm2 on ultrasonography.Results
Of the 847 eligible women, 608 (72 %) were examined. Data on POP symptoms, POP-Q stage, levator avulsion and levator hiatal area were available in 598, 608, 606 and 554 women, respectively, and of these 75 (13 %) had sPOP, 275 (45 %) had POP-Q ≥2, 113 (19 %) had levator avulsion and 164 (30 %) had a levator hiatal area >40 cm2. Levator avulsion was associated with POP-Q ≥2 with an odds ratio (OR) of 9.91 and a 95 % confidence interval (CI) of 5.73 – 17.13, and with sPOP (OR 2.28, 95 % CI 1.34 – 3.91). Levator hiatal area >40 cm2 was associated with POP-Q ≥2 (OR 6.98, 95 % CI 4.54, – 10.74) and sPOP (OR 3.28, 95 % CI 1.96 – 5.50).Conclusion
Many healthy women selected from the general population have symptoms and signs of POP 20 years after their first delivery, and PFMT is associated with POP-Q ≥2 and sPOP.1000.
Etienne W. Henn Thando Nondabula Leonard Juul 《International urogynecology journal》2016,27(3):407-412