全文获取类型
收费全文 | 1912911篇 |
免费 | 139388篇 |
国内免费 | 5375篇 |
专业分类
耳鼻咽喉 | 24694篇 |
儿科学 | 62698篇 |
妇产科学 | 50957篇 |
基础医学 | 285642篇 |
口腔科学 | 53287篇 |
临床医学 | 181531篇 |
内科学 | 366925篇 |
皮肤病学 | 39930篇 |
神经病学 | 151815篇 |
特种医学 | 69603篇 |
外国民族医学 | 433篇 |
外科学 | 271315篇 |
综合类 | 41778篇 |
现状与发展 | 3篇 |
一般理论 | 610篇 |
预防医学 | 156467篇 |
眼科学 | 42914篇 |
药学 | 142541篇 |
9篇 | |
中国医学 | 5187篇 |
肿瘤学 | 109335篇 |
出版年
2021年 | 15228篇 |
2019年 | 15905篇 |
2018年 | 22382篇 |
2017年 | 17009篇 |
2016年 | 18532篇 |
2015年 | 21135篇 |
2014年 | 28985篇 |
2013年 | 44458篇 |
2012年 | 60543篇 |
2011年 | 64090篇 |
2010年 | 37412篇 |
2009年 | 34644篇 |
2008年 | 58932篇 |
2007年 | 62470篇 |
2006年 | 63069篇 |
2005年 | 60373篇 |
2004年 | 57909篇 |
2003年 | 55063篇 |
2002年 | 53513篇 |
2001年 | 89490篇 |
2000年 | 91733篇 |
1999年 | 76567篇 |
1998年 | 21127篇 |
1997年 | 18709篇 |
1996年 | 18799篇 |
1995年 | 17843篇 |
1994年 | 16599篇 |
1993年 | 15480篇 |
1992年 | 60305篇 |
1991年 | 59145篇 |
1990年 | 57383篇 |
1989年 | 55295篇 |
1988年 | 50893篇 |
1987年 | 49522篇 |
1986年 | 47170篇 |
1985年 | 44779篇 |
1984年 | 33420篇 |
1983年 | 28484篇 |
1982年 | 16636篇 |
1979年 | 30450篇 |
1978年 | 21524篇 |
1977年 | 17852篇 |
1976年 | 17358篇 |
1975年 | 18198篇 |
1974年 | 22012篇 |
1973年 | 21379篇 |
1972年 | 19858篇 |
1971年 | 18471篇 |
1970年 | 17374篇 |
1969年 | 15886篇 |
排序方式: 共有10000条查询结果,搜索用时 18 毫秒
11.
Jodie Ward Rebecca N. Johnson Linzi Wilson-Wilde 《The Australian journal of forensic sciences》2019,51(4):S263-S267
ABSTRACTFemales are underrepresented in science, technology, engineering and mathematics (STEM) at all levels of society. Fewer females are completing STEM school subjects, graduating with STEM degrees, being employed as STEM professionals, and holding senior leadership and academic positions in STEM. However, unlike almost every other STEM discipline, the overall ratio of females is higher in many forensic science disciplines. For our sector, rather than having difficulty in attracting females, the bigger issue is how we retain and promote female talent. This complex issue is exacerbated by: gender pay gaps; family role expectations; lack of visible role models or mentors; discrimination and harassment; and bias during recruitment and promotion practices. We discuss barriers relevant for women in the forensic industry and offer potential solutions. These include flexible work arrangements, sponsorship programmes, and fostering and practising an inclusive workplace culture. Gender equity programmes and exemplar STEM organizations focused on a commitment to gender parity will be explored. Harnessing untapped female talent is as much a social justice issue as employing best practices for improving the quality, diversity and output of our forensic science workforce, and research and innovation strategies. 相似文献
12.
Michelle Y L Tang Patrick H Y Chung Hau Y Chan Paul K H Tam Kenneth KY Wong 《Journal of pediatric surgery》2019,54(2):255-257
Objective
Helicobacter pylori infection is common among Asians. However, evidence in the recent years has demonstrated a decrease in the prevalence of H. pylori infection among children and adults worldwide. Our aim was to update its prevalence in symptomatic children in our locality in the recent 12?years and compared to the results of our previous review published in 2005.Methods
A retrospective review was carried out between 2005 and 2017. All children who presented with dyspepsia or gastrointestinal bleeding and underwent oesophagogastroduodenoscopy with antral biopsy taken were included. Patient demographics, endoscopic, or histological diagnosis and the H. pylori status were recorded.Main Results
A total of 602 patients were included. There was a statistically significant decreasing trend of H. pylori infection rate between 2005 and 2017 (p?=?0.003). The overall infection rate from this study was 12.8%, compared to 25.6% from our previous review. Overall failure of eradication with first-line antibiotic therapy has increased to 29.3% from 10% in our previous review.Conclusion
There was a decrease in the prevalence of H. pylori infection among symptomatic children for the recent 12?years, comparing to our previous data from 2005. We hypothesize that the reduction in prevalence of H. pylori infection among adults and the decrease in the practice of sharing chopsticks during meals have led to a decrease in transmission of the bacteria among family members in Hong Kong. However, the failure of eradication with first line treatment was higher, possibly due to the increase in antibiotics usage and resistance.Level of Evidence
III 相似文献13.
Daniel S. Tsze Sharon S. Pan Kerrin C. DePeter Anju M. Wagh Stephen L. Gordon Peter S. Dayan 《The American journal of emergency medicine》2019,37(6):1128-1132
ObjectivesWe aimed to describe the analgesic efficacy, duration of analgesia, and adverse event profile associated with intranasal hydromorphone in children with acute pain presenting to an emergency department.MethodsProspective dose titration pilot study of otherwise healthy children 4 to 17-years-old with moderate to severe pain who required a parenteral opioid. All patients received an initial intranasal hydromorophone dose of 0.03 mg/kg. The need for additional analgesia was assessed at 15 and 30 min; an additional 0.015 mg/kg was given at each assessment, if required. Need for rescue analgesic, pain intensity and adverse events were assessed until 6 h after hydromorphone administration or until patients were discharged, underwent a procedure to treat their painful condition, or received a rescue analgesic.ResultsWe enrolled 35 children. Fifteen, 11, and 9 children required a total dose of 0.03, 0.045, and 0.06 mg/kg, respectively. Patients in each dose group experienced an absolute decrease in pain score of ≥3/10 and percent reduction >40% within 5–15 min of completing dose-titration administration of hydromorphone. Duration of analgesia (i.e. time until rescue analgesic administered) >1 h was observed in 85.7% of patients. Patients not requiring rescue analgesics had mild or no pain until discharged or their painful conditions were treated. Three (8.6%) patients required a rescue analgesic <1 h after hydromorphone administration. There were no major adverse events.ConclusionsIntranasal hydromorphone led to rapid, clinically significant and frequently sustained decreases in pain intensity in children. No major adverse events were observed in this preliminary sample.Clinical Trials Registration Number: NCT02437669 相似文献
14.
Christopher N. Cooley Tyler J. Beranek Matthew A. Warpinski Robert Alexander Amanda O. Esquivel 《The American journal of emergency medicine》2019,37(2):199-203
Introduction
In the United States there has been a large increase in participation in lacrosse for both males and females. The purpose of this study was to analyze the number of head injuries, injury rates (calculated using the reported number of participants) and types of head injuries that are seen in emergency departments in the United States.Methods
We compared injuries between male and female lacrosse participants. This was a retrospective study using a publicly available database produced by the US Consumer Product Safety Commission and information about lacrosse participation from US Lacrosse.Results
A linear regression was performed and showed a positive correlation between number of head injuries to males and time from 2002 to 2010 (R2?=?0.823; p?=?0.001). While the number of injuries to the head in female lacrosse participants was not significant. There was a negative correlation between the number of head injuries to males from 2010 to 2016 (R2?=?0.800; p?=?0.007), but again, there was no significance for female injury count (R2?=?0.417; p?=?0.117). Other significant differences between head injuries in males and females included the mechanism of injury and the type of injury recorded.Conclusion
The most recent data from 2010 to 2016, suggest that both males and females have had a decrease in injury rate. However the total number of female head injuries is not significantly decreasing and as the sport continues to grow there will likely be more total head injuries and visits to the emergency department. 相似文献15.
Jae Eun Choi Tyler Werbel Zhenping Wang Chia Chi Wu Tony L. Yaksh Anna Di Nardo 《Journal of dermatological science》2019,93(1):58-64
Background
Rosacea is a chronic inflammatory skin condition whose etiology has been linked to mast cells and the antimicrobial peptide cathelicidin LL-37. Individuals with refractory disease have demonstrated clinical benefit with periodic injections of onabotulinum toxin, but the mechanism of action is unknown.Objectives
To investigate the molecular mechanism by which botulinum toxin improves rosacea lesions.Methods
Primary human and murine mast cells were pretreated with onabotulinum toxin A or B or control. Mast cell degranulation was evaluated by β-hexosaminidase activity. Expression of botulinum toxin receptor Sv2 was measured by qPCR. The presence of SNAP-25 and VAMP2 was established by immunofluorescence. In vivo rosacea model was established by intradermally injecting LL-37 with or without onabotulinum toxin A pretreatment. Mast cell degranulation was assessed in vivo by histologic counts. Rosacea biomarkers were analyzed by qPCR of mouse skin sections.Results
Onabotulinum toxin A and B inhibited compound 48/80-induced degranulation of both human and murine mast cells. Expression of Sv2 was established in mouse mast cells. Onabotulinum toxin A and B increased cleaved SNAP-25 and decreased VAMP2 staining in mast cells respectively. In mice, injection of onabotulinum toxin A significantly reduced LL-37-induced skin erythema, mast cell degranulation, and mRNA expression of rosacea biomarkers.Conclusions
These findings suggest that onabotulinum toxin reduces rosacea-associated skin inflammation by directly inhibiting mast cell degranulation. Periodic applications of onabotulinum toxin may be an effective therapy for refractory rosacea and deserves further study. 相似文献16.
17.
D. Gareth Evans Kelly-Anne Phillips Roger L. Milne Robert Fruscio Cezary Cybulski Jacek Gronwald Jan Lubinski Tomasz Huzarski Zerin Hyder Claire Forde Kelly Metcalfe Leigha Senter Jeffrey Weitzel Nadine Tung Dana Zakalik Maria Ekholm Ping Sun Steven A. Narod kConFab Investigators Polish Hereditary
Breast Cancer Consortium Hereditary Breast Cancer Clinical Study Group 《British journal of cancer》2021,124(9):1524
Background The impact of various breast-cancer treatments on patients with a BRCA2 mutation has not been studied. We sought to estimate the impact of bilateral oophorectomy and other treatments on breast cancer-specific survival among patients with a germline BRCA2 mutation.Methods We identified 664 women with stage I–III breast cancer and a BRCA2 mutation by combining five different datasets (retrospective and prospective). Subjects were followed for 7.2 years from diagnosis to death from breast cancer. Tumour characteristics and cancer treatments were patient-reported and derived from medical records. Predictors of survival were determined using Cox proportional hazard models, adjusted for other treatments and for prognostic features.Results The 10-year breast-cancer survival for ER-positive patients was 78.9% and for ER-negative patients was 82.3% (adjusted HR = 1.23 (95% CI, 0.62–2.45, p = 0.55)). The 10-year breast-cancer survival for women who had a bilateral oophorectomy was 89.1% and for women who did not have an oophorectomy was 59.0% (adjusted HR = 0.45; 95% CI, 0.28–0.72, p = 0.001). The adjusted hazard ratio for chemotherapy was 0.83 (95% CI, 0.65–1.53: p = 0.56).Conclusions For women with breast cancer and a germline BRCA2 mutation, positive ER status does not predict superior survival. Oophorectomy is associated with a reduced risk of death from breast cancer and should be considered in the treatment plan.Subject terms: Targeted therapies, Breast cancer 相似文献
18.
Roberto L. Cazzato Pierre De Marini Ian Leonard-Lorant Danoob Dalili Guillaume Koch Pierre A. Autrusseau Theo Mayer Julia Weiss Pierre Auloge Julien Garnon Afshin Gangi 《Diagnostic and interventional imaging》2021,102(6):355-361
PurposeTo retrospectively report on safety, pain relief and local tumor control achieved with percutaneous ablation of sacral bone metastases.Materials and methodsFrom February 2009 to June 2020, 23 consecutive patients (12 women and 11 men; mean age, 60 ± 8 [SD] years; median, 60; range: 48-80 years) with 23 sacral metastases underwent radiofrequency (RFA) or cryo-ablation (CA), with palliative or curative intent at our institution. Patients’ demographics and data pertaining to treated metastases, procedure-related variables, safety, and clinical evolution following ablation were collected and analyzed. Pain was assessed with numerical pain rating scale (NPRS).ResultsSixteen (70%) patients were treated with palliative and 7 (30%) with curative intent. Mean tumor diameter was 38 ± 19 (SD) mm (median, 36; range: 11-76). External radiation therapy had been performed on five metastases (5/23; 22%) prior to ablation. RFA was used in 9 (39%) metastases and CA in the remaining 14 (61%). Thermo-protective measures and adjuvant bone consolidation were used whilst treating 20 (87%) and 8 (35%) metastases, respectively. Five (22%) minor complications were recorded. At mean 31 ± 21 (SD) (median, 32; range: 2-70) months follow-up mean NPRS was 2 ± 2 (SD) (median, 1; range: 0–6) vs. 5 ± 1 (median, 5; range: 4–8; P < 0.001) at the baseline. Three metastases out of 7 (43%) undergoing curative ablation showed local progression at mean 4 ± 4 (SD) (median, 2; range: 1-8) months follow-up.ConclusionPercutaneous ablation of sacral metastases is safe and results in significant long-lasting pain relief. Local tumor control seems sub-optimal; however, further investigations are needed to confirm these findings due to paucity of data. 相似文献
19.
B. Kowall N. Lehmann A.A. Mahabadi S. Moebus R. Erbel K.H. Jöckel A. Stang 《Nutrition, metabolism, and cardiovascular diseases : NMCD》2019,29(3):228-235
Background and aims
There is controversy on the potentially benign nature of metabolically healthy obesity (MHO), i.e., obese persons with few or no metabolic abnormalities. So far, associations between MHO and coronary artery calcification (CAC), a measure of subclinical atherosclerosis, have mainly been studied cross-sectionally in Asian populations. We assessed cross-sectional and longitudinal MHO CAC associations in a Caucasian population.Methods and results
In the Heinz Nixdorf Recall Study, a population-based cohort study in Germany, CAC was assessed by electron-beam tomography at baseline and at 5-year follow-up. For cross-sectional and longitudinal analyses, we included 1585 participants free of coronary heart disease at baseline, with CAC measurements at baseline and at follow-up, and with either normal weight (BMI 18.5–24.9 kg/m2) or obesity (BMI ≥30.0 kg/m2) at baseline. We used four definitions of MHO. In our main analysis, we defined obese persons as metabolically healthy if they met ≤1 of the NCEP ATP III criteria for the definition of the metabolic syndrome – waist circumference was not taken into account because of collinearity with BMI.Persons with MHO had a higher prevalence of CAC than metabolically healthy normal weight (MHNW) persons (prevalence ratio = 1.59 (95% confidence interval 1.38–1.84) for the main analysis). Persons with MHO had slightly larger odds of CAC progression than persons with MHNW (odds ratios ranged from 1.17 (0.69–1.99) to 1.48 (1.02–2.13) depending on MHO definition and statistical approach).Conclusion
Our analyses on MHO CAC associations add to the evidence that MHO is not a purely benign health condition. 相似文献20.
Bo Yang Elizabeth L. Norton Terry Shih Linda Farhat Xiaoting Wu Whitney E. Hornsby Karen M. Kim Himanshu J. Patel G. Michael Deeb 《The Journal of thoracic and cardiovascular surgery》2019,157(4):1313-1321.e2