全文获取类型
| 收费全文 | 948858篇 |
| 免费 | 60657篇 |
| 国内免费 | 1455篇 |
专业分类
| 耳鼻咽喉 | 13228篇 |
| 儿科学 | 24442篇 |
| 妇产科学 | 23275篇 |
| 基础医学 | 134691篇 |
| 口腔科学 | 28450篇 |
| 临床医学 | 81530篇 |
| 内科学 | 185819篇 |
| 皮肤病学 | 19597篇 |
| 神经病学 | 73078篇 |
| 特种医学 | 37219篇 |
| 外国民族医学 | 79篇 |
| 外科学 | 153331篇 |
| 综合类 | 18107篇 |
| 现状与发展 | 2篇 |
| 一般理论 | 234篇 |
| 预防医学 | 62173篇 |
| 眼科学 | 21456篇 |
| 药学 | 73495篇 |
| 31篇 | |
| 中国医学 | 2332篇 |
| 肿瘤学 | 58401篇 |
出版年
| 2018年 | 9279篇 |
| 2017年 | 7271篇 |
| 2016年 | 8159篇 |
| 2015年 | 9331篇 |
| 2014年 | 12565篇 |
| 2013年 | 18126篇 |
| 2012年 | 25101篇 |
| 2011年 | 25922篇 |
| 2010年 | 15268篇 |
| 2009年 | 14635篇 |
| 2008年 | 25090篇 |
| 2007年 | 26171篇 |
| 2006年 | 26864篇 |
| 2005年 | 25796篇 |
| 2004年 | 24808篇 |
| 2003年 | 23849篇 |
| 2002年 | 23348篇 |
| 2001年 | 54861篇 |
| 2000年 | 56684篇 |
| 1999年 | 47055篇 |
| 1998年 | 10781篇 |
| 1997年 | 9505篇 |
| 1996年 | 9606篇 |
| 1995年 | 8947篇 |
| 1994年 | 8298篇 |
| 1993年 | 7609篇 |
| 1992年 | 35508篇 |
| 1991年 | 33927篇 |
| 1990年 | 32751篇 |
| 1989年 | 31878篇 |
| 1988年 | 29002篇 |
| 1987年 | 28257篇 |
| 1986年 | 26296篇 |
| 1985年 | 25152篇 |
| 1984年 | 17837篇 |
| 1983年 | 15145篇 |
| 1982年 | 7797篇 |
| 1981年 | 6774篇 |
| 1979年 | 15785篇 |
| 1978年 | 10598篇 |
| 1977年 | 9053篇 |
| 1976年 | 7875篇 |
| 1975年 | 8629篇 |
| 1974年 | 10467篇 |
| 1973年 | 9859篇 |
| 1972年 | 9357篇 |
| 1971年 | 8853篇 |
| 1970年 | 8427篇 |
| 1969年 | 7923篇 |
| 1968年 | 7200篇 |
排序方式： 共有10000条查询结果，搜索用时 13 毫秒
11.
Ji-Hyun Lee Jung-il Bae Young-Eun Jang Eun-Hee Kim Hee-Soo Kim Jin-Tae Kim 《British journal of anaesthesia》2019,122(5):692-701
Background
Perioperative ventilatory strategies for lung protection in children are underexplored. This study evaluated the effects of lung protective ventilation (LPV) on postoperative clinical outcomes in children requiring one-lung ventilation (OLV) for pulmonary resection.Methods
Children age ≤5 yr scheduled for video-assisted thoracoscopic lung lobectomy or segmentectomy were randomly assigned to LPV or control ventilation. For LPV, tidal volume (VT) was 6 ml kg?1 during two-lung ventilation (TLV(VT)), 4 ml kg?1 during OLV, with 6 cm H2O PEEP maintained throughout. In the control group, TLV(VT) was 10 ml kg?1, 8 ml kg?1 during OLV, but without PEEP. The primary outcome was the incidence of pulmonary complications within 72 h after operation. Secondary outcomes included intraoperative desaturation, arterial oxygen partial pressure/inspiratory fraction of oxygen (P/F) ratio >40 kPa, and development of consolidation and B-lines (assessed by lung ultrasound at the end of surgery, by an investigator masked to group allocation). Odds ratio (OR) with 95% confidence intervals are reported.Results
Overall, 19/110 (17.3%) children sustained pulmonary complications after surgery. LPV reduced pulmonary complications (5/55; 9.1%), compared with 14/55 (25.5%) children sustaining complications in the control group (OR=0.29 [0.10–0.88]; P=0.02). Masked ultrasound assessment showed less consolidation, and fewer B-lines, after LPV (P<0.001). Intraoperative desaturation was more common in control mode (eight/55; 14.5%), compared with 1/55 (1.8%) after LPV (OR=9.2 [1.1–76]; P=0.015). LPV maintained (P/F) ratio >40 more frequently (53/55; 96.4%) than control-mode (45/55; 81.8%) ventilation (OR=5.9 [1.2–28.3%]; P<0.01).Conclusions
Lung protective ventilation decreased postoperative pulmonary complications compared with conventional ventilation in children requiring one-lung ventilation for pulmonary resection.Clinical trial registration
NCT02680925. 相似文献12.
R.J. van de Peppel M.T. van der Beek L.G. Visser M.G.J. de Boer J. Wallinga 《International journal of antimicrobial agents》2019,53(3):284-293
Objectives
Triazole resistance in Aspergillus spp. is emerging and complicates prophylaxis and treatment of invasive aspergillosis (IA) worldwide. New polymerase chain reaction (PCR) tests on broncho-alveolar lavage (BAL) fluid allow for detection of triazole resistance at a genetic level, which has opened up new possibilities for targeted therapy. In the absence of clinical trials, a modelling study delivers estimates of the added value of resistance detection with PCR, and which empiric therapy would be optimal when local resistance rates are known.Design
A decision-analytic modelling study was performed based on epidemiological data of IA, extended with estimated dynamics of resistance rates and treatment effectiveness. Six clinical strategies were compared that differ in use of PCR diagnostics (used vs not used) and in empiric therapeutic choice in case of unknown triazole susceptibility: voriconazole, liposomal amphotericin B (LAmB) or both. Outcome measures were proportion of correct treatment, survival and serious adverse events.Results
Implementing aspergillus PCR tests was projected to result in residual treatment-susceptibility mismatches of <5% for a triazole resistance rate up to 20% (using voriconazole). Empiric LAmB outperformed voriconazole at resistance rates >5–20%, depending on PCR use and estimated survival benefits of voriconazole over LAmB. Combination therapy of voriconazole and LAmB performed best at all resistance rates, but the advantage over the other strategies should be weighed against the expected increased number of drug-related serious adverse events. The advantage of combination therapy over LAmB monotherapy became smaller at higher triazole resistance rates.Conclusions
Introduction of current aspergillus PCR tests on BAL fluid is an effective way to increase the proportion of patients that receive targeted therapy for IA. The results indicate that close monitoring of background resistance rates and adverse drug events are important to attain the potential benefits of LAmB. The choice of strategy ultimately depends on the probability of triazole resistance, the availability of PCR and individual patient characteristics. 相似文献13.
Aaron T. Seaman 《Medical anthropology》2020,39(1):29-40
ABSTRACTSpousal caregivers draw upon understandings of shifting relationality to maintain a familial understanding of their spouse with Alzheimer’s disease. Working through what it means to think of an adult with Alzheimer’s disease “like a child,” I trace how spouses negotiate their shifting relationships across the course of Alzheimer’s. While regarding adults as childlike can be perceived as dehumanizing infantilization, for families living with Alzheimer’s disease, conceiving of one’s spouse as like a child can actually enable processes of continued care, sustained recognition, and love to uphold personhood in the midst of often radical change. 相似文献
14.
Chahine C. Assi Hanane B. Barakat Jacques H. Caton Elie N. Najjar Camille T. Samaha Kaissar F. Yammine 《The Journal of arthroplasty》2019,34(2):333-337
Background
The dual mobility cups (DMCs) were shown to reduce dislocation rate following total hip arthroplasty for any etiology, including femoral neck fractures. No reported studies evaluating DMC results for femoral neck fracture in a Middle Eastern population were found in the literature.Methods
This study aims to look for mortality rate, clinical, and functional outcomes in a population having specific rituals involving extreme hip positions as part of their daily activities.Results
Of an initial sample of 174 patients (177 operated hips), 18 (10.3%) patients (20 hips) died after a mean of 39.6 ± 13.8 months (ranging from 2 to 49 months) with only 3 (1.7%) during the first post-operative year. Twelve patients (13 hips) were lost to follow-up and 19 patients (19 hips) had their radiological data incomplete. In the final sample of 125 patients (125 hips), no dislocation, aseptic loosening, or infection was encountered. The mean modified Hip Harris Score was of 94.8 ± 8.4. The mean modified Hip Harris Score of 40 patients who used to practice regularly oriental sitting position or prayers was 94.1 ± 3.1. After surgery, 36 of these 40 patients (90%) described their hip as “a forgotten hip.” Multivariate analyses found correlation only between mortality and cardiovascular co-morbidities.Conclusion
DMC implants showed excellent clinical and functional results. The majority of patients having rituals and customs involving extreme hip positions were able to resume their daily activities. The observed low mortality rate should incite future research to investigate its correlation with the use of DMCs. 相似文献15.
Francesco Grigioni Giovanni Benfari Jean-Louis Vanoverschelde Christophe Tribouilloy Jean-Francois Avierinos Francesca Bursi Rakesh M. Suri Federico Guerra Agnés Pasquet Dan Rusinaru Emanuela Marcelli Alexis Théron Andrea Barbieri Hector Michelena Siham Lazam Catherine Szymanski Vuyisile T. Nkomo Alessandro Capucci L. Bacchi-Reggiani 《Journal of the American College of Cardiology》2019,73(3):264-274
Background
Scientific guidelines consider atrial fibrillation (AF) complicating degenerative mitral regurgitation (DMR) a debated indication for surgery.Objectives
This study analyzed the prognostic/therapeutic implications of AF at DMR diagnosis and long-term.Methods
Patients were enrolled in the MIDA (Mitral Regurgitation International Database) registry, which reported the consecutive, multicenter, international experience with DMR due to flail leaflets echocardiographically diagnosed.Results
Among 2,425 patients (age 67 ± 13 years; 71% male, 67% asymptomatic, ejection fraction 64 ± 10%), 1,646 presented at diagnosis with sinus rhythm (SR), 317 with paroxysmal AD, and 462 with persistent AF. Underlying clinical/instrumental characteristics progressively worsened from SR to paroxysmal to persistent AF. During follow-up, paroxysmal and persistent AF were associated with excess mortality (10-year survival in SR and in paroxysmal and persistent AF was 74 ± 1%, 59 ± 3%, and 46 ± 2%, respectively; p < 0.0001), that persisted 20 years post-diagnosis and independently of all baseline characteristics (p values <0.0001). Surgery (n = 1,889, repair 88%) was associated with better survival versus medical management, regardless of all baseline characteristics and rhythm (adjusted hazard ratio: 0.26; 95% confidence interval: 0.23 to 0.30; p < 0.0001) but post-surgical outcome remained affected by AF (10-year post-surgical survival in SR and in paroxysmal and persistent AF was 82 ± 1%, 70 ± 4%, and 57 ± 3%, respectively; p < 0.0001).Conclusions
AF is a frequent occurrence at DMR diagnosis. Although AF is associated with older age and more severe presentation of DMR, it is independently associated with excess mortality long-term after diagnosis. Surgery is followed by improved survival in each cardiac rhythm subset, but persistence of excess risk is observed for each type of AF. Our study indicates that detection of AF, even paroxysmal, should trigger prompt consideration for surgery. 相似文献16.
Hanna Lee Mary K. Tan Andrew T. Yan Paul Angaran Paul Dorian Claudia Bucci Jean C. Gregoire Alan D. Bell Martin S. Green Peter L. Gross Allan Skanes Charles R. Kerr L. Brent Mitchell Jafna L. Cox Vidal Essebag Brett Heilbron Krishnan Ramanathan Carl Fournier Shaun G. Goodman 《The Canadian journal of cardiology》2019,35(2):160-168
Background
Physicians treating nonvalvular atrial fibrillation (AF) assess stroke and bleeding risks when deciding on anticoagulation. The agreement between empirical and physician-estimated risks is unclear. Furthermore, the association between patient and physician sex and anticoagulation decision-making is uncertain.Methods
We pooled data from 2 national primary care physician chart audit databases of patients with AF (Facilitating Review and Education to Optimize Stroke Prevention in Atrial Fibrillation and Coordinated National Network to Engage Physicians in the Care and Treatment of Patients with Atrial Fibrillation Chart Audit) with a combined 1035 physicians (133 female, 902 male) and 10,927 patients (4567 female and 6360 male).Results
Male physicians underestimated stroke risk in female patients and overestimated risk in male patients. Female physicians estimated stroke risk well in female patients but underestimated the risk in male patients. Risk of bleeding was underestimated in all. Despite differences in risk assessment by physician and patient sex, > 90% of patients received anticoagulation across all subgroups. There was modest agreement between physician estimated and calculated (ie, CHADS2 score) stroke risk: Kappa scores were 0.41 (0.35-0.47) for female physicians and 0.34 (0.32-0.36) for male physicians.Conclusions
Our study is the first to examine the association between patient and physician sex influences and stroke and bleeding risk estimation in AF. Although there were differences in agreement between physician estimated stroke risk and calculated CHADS2 scores, these differences were small and unlikely to affect clinical practice; further, despite any perceived differences in the accuracy of risk assessment by sex, most patients received anticoagulation. 相似文献17.
Background and purpose — 1 in 5 patients are dissatisfied following unicompartmental or total knee arthroplasty (UKA or TKA). This may be partly explained by failing to return to desired activity post-arthroplasty. To facilitate return to desired activity, a greater understanding of predictors of return to desired activity in UKA and TKA patients is needed. We compared rates of return to desired activity 12 months following UKA vs. TKA, and identified and compared predictors of return to desired activity 12 months following UKA vs. TKA.
Patients and methods — Patients were prospectively recruited from 2 hospitals prior to undergoing UKA or primary TKA. Patients reported preoperatively the activity/activities that were limited due to their knee that they wished to return to after arthroplasty. At 12-months postoperatively, patients reported whether they had returned to these activities (‘return to desired activity’). Preoperative predictors evaluated were age, sex, BMI, education, comorbidities, pain expectations, Oxford Knee Score (OKS), UCLA Activity Score, and EQ-5D. Generalized linear models assessed the relationship between potential predictors and return-to-desired-activity.
Results — The response rate of all patients eligible for 12-month follow-up was 74%. TKA patients (n = 575) were older (mean (SD) 70 (9) vs. 67 (10)) with a greater BMI (31 (6) vs. 30 (5)) than patients undergoing UKA (n = 420). 75% of UKA and 59% of TKA patients returned to desired activity. TKA patients had a greater risk of non-return to desired activity than patients undergoing UKA (risk ratio (95% CI) 1.5 (1.2–1.8)). Predictors of non-return to desired activity following UKA were worse OKS (0.96 (0.93–0.99)), higher BMI (1.04 (1.01–1.08)), and worse expectations (1.9 (1.2–2.8)). Predictors of non-return to desired activity following TKA were worse EQ-5D (0.53 (0.33–0.85)) and worse OKS (0.98 (0.96–1.0)).
Interpretation — UKA patients were more likely to return to desired activity than TKA patients. Predictors of return to desired activity differed following UKA and TKA. Optimizing selection of arthroplasty procedure based on patient characteristics and targeting predictors of poor outcome may facilitate return to desired activity with potential to enhance postoperative satisfaction. 相似文献
18.
K.A. Lee M.T.A. Sharabiani D. Tumino J. Wadsley V. Gill G. Gerrard R. Sindhu M.N. Gaze L. Moss K. Newbold 《Clinical oncology (Royal College of Radiologists (Great Britain))》2019,31(6):385-390
Aims
To obtain an overview of the management and outcomes of children aged 18 years or younger diagnosed with differentiated thyroid carcinoma of follicular cell origin across the UK, by collecting and analysing data from the limited number of centres treating these patients. This multicentre data might provide a more realistic perspective than single-institution series.Materials and methods
Six centres submitted data extracted from historical records on patients aged 18 years or younger, diagnosed between 1964 and 2017. The univariate and multivariable Cox proportional hazard model was used to identify potential predictors of progression-free survival, using national data as a control.Results
Data on 166 patients were available for analysis. Females (74%) were predominant, and the age ranged from 3 to 19 years at diagnosis, mean 14.1 years. Nodal metastases were present in 51%; 12% had distant metastases. After surgery, 95% received radioactive iodine (39% on more than one occasion) and 4% received external beam radiotherapy. With a median follow-up duration of 5 years, 69% are alive with no evidence of disease; 20% are alive with a raised thyroglobulin level as the only evidence of residual disease; 6% have residual structural disease detectable on imaging; 2% have died, from cerebral metastases.Conclusion
Despite most patients having advanced disease at presentation, outcomes are very good. A national prospective registry should allow systematic collection of good-quality data and may facilitate research to further improve outcomes. 相似文献19.