全文获取类型
收费全文 | 2351618篇 |
免费 | 181626篇 |
国内免费 | 7720篇 |
专业分类
耳鼻咽喉 | 31938篇 |
儿科学 | 77448篇 |
妇产科学 | 66449篇 |
基础医学 | 331949篇 |
口腔科学 | 65952篇 |
临床医学 | 207359篇 |
内科学 | 469300篇 |
皮肤病学 | 53495篇 |
神经病学 | 189225篇 |
特种医学 | 94372篇 |
外国民族医学 | 617篇 |
外科学 | 365238篇 |
综合类 | 52536篇 |
现状与发展 | 3篇 |
一般理论 | 684篇 |
预防医学 | 183069篇 |
眼科学 | 52569篇 |
药学 | 171933篇 |
38篇 | |
中国医学 | 4269篇 |
肿瘤学 | 122521篇 |
出版年
2018年 | 22820篇 |
2016年 | 20767篇 |
2015年 | 23461篇 |
2014年 | 32668篇 |
2013年 | 49400篇 |
2012年 | 63432篇 |
2011年 | 67979篇 |
2010年 | 41656篇 |
2009年 | 40072篇 |
2008年 | 64539篇 |
2007年 | 69521篇 |
2006年 | 70930篇 |
2005年 | 69137篇 |
2004年 | 66338篇 |
2003年 | 64556篇 |
2002年 | 62328篇 |
2001年 | 108074篇 |
2000年 | 111266篇 |
1999年 | 93747篇 |
1998年 | 27859篇 |
1997年 | 25013篇 |
1996年 | 25851篇 |
1995年 | 25347篇 |
1994年 | 23908篇 |
1993年 | 22270篇 |
1992年 | 77422篇 |
1991年 | 75864篇 |
1990年 | 73880篇 |
1989年 | 70834篇 |
1988年 | 66037篇 |
1987年 | 64742篇 |
1986年 | 61601篇 |
1985年 | 59089篇 |
1984年 | 44726篇 |
1983年 | 38239篇 |
1982年 | 23581篇 |
1981年 | 21064篇 |
1980年 | 19754篇 |
1979年 | 41455篇 |
1978年 | 29677篇 |
1977年 | 25295篇 |
1976年 | 23558篇 |
1975年 | 25322篇 |
1974年 | 29833篇 |
1973年 | 28621篇 |
1972年 | 26816篇 |
1971年 | 24852篇 |
1970年 | 22905篇 |
1969年 | 21852篇 |
1968年 | 20534篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
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
22.
23.
T. Maishman H. Sheikh P. Boger J. Kelly K. Cozens A. Bateman S. Davies M. Fay D. Sharland A. Jackson 《Clinical oncology (Royal College of Radiologists (Great Britain))》2021,33(5):e225-e231
AimsSelf-expanding metal stents provide rapid improvement of dysphagia in oesophageal cancer but are associated with complications. The aim of the present study was to test the effectiveness of an alternative treatment of combining biodegradable stents with radiotherapy.Materials and methodsA Simon two-stage single-arm prospective phase II trial design was used to determine the efficacy of biodegradable stents plus radiotherapy in patients with dysphagia caused by oesophagus cancer who were unsuitable for radical treatment. Fourteen patients were recruited and data from 12 were included in the final analyses.ResultsFive of 12 patients met the primary end point: one stent-related patient death; four further interventions for dysphagia within 16 weeks of stenting (41.7%, 95% confidence interval 15.2–72.3%). The median time to a 10-point deterioration of quality of life was 2.7 weeks. Nine patients died within 52 weeks of registration. The median time to death from any cause was 15.0 weeks (95% confidence interval 9.6–not reached).ConclusionThe high re-intervention observed, which met the pre-defined early stopping criteria, meant that the suggested alternative treatment was not sufficiently effective to be considered for a larger scale trial design. Further work is needed to define the place of biodegradable stents in the management of malignant oesophageal strictures. 相似文献
24.
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
Objective
To compare perioperative and long-term outcomes in patients undergoing hemiarch and aggressive arch replacement for acute type A aortic dissection (ATAAD).Methods
From 1996 to 2017, we compared outcomes of hemiarch (n = 322) versus aggressive arch replacements (zones 2 and 3 arch replacement with implantation of 2-4 arch branches, n = 150) in ATAAD. Indications for aggressive arch were arch aneurysm >4 cm or intimal tear in the aortic arch that was not resectable by hemiarch replacement, or dissection of arch branches with malperfusion.Results
Patients in the aggressive arch group were significantly younger (mean age: 57 vs 61 years old) and had significantly longer hypothermic circulatory arrest, cardiopulmonary bypass, and aortic crossclamp times. There were no significant differences in perioperative outcomes between hemiarch and aggressive arch groups, including 30-day mortality (5.3% vs 7.3%, P = .38) and postoperative stroke rate (7% vs 7%, P = .96). Over 15 years, Kaplan–Meier survival was similar between hemiarch and aggressive arch groups (log-rank P = .55, 10-year survival 70% vs 72%). Given death as a competing factor, incidence rates of reoperation over 15 years (2.1% vs 2.0% per year, P = 1) and 10-year cumulative incidence of reoperation (14% vs 12%, P = .89) for arch and distal aorta pathology were similar between the 2 groups.Conclusions
Both hemiarch and aggressive arch replacement are appropriate approaches for select patients with ATAAD. Aggressive arch replacement should be considered for an arch aneurysm >4 cm or an intimal tear at the arch unable to be resected by hemiarch replacement, or dissection of the arch branches with malperfusion. 相似文献25.
Aasha I. Hoogland Hailey W. Bulls Brian D. Gonzalez Brent J. Small Lianqi Liu Joseph Pidala Heather S.L. Jim Asmita Mishra 《Journal of pain and symptom management》2019,57(5):952-960.e1
Context
Quality of life (QoL) is increasingly recognized as an important outcome of cancer treatment. Previous studies have examined clinical predictors of QoL, but with the increasing prevalence of wearable sensors that monitor sleep and activity patterns, further investigation into whether these behaviors are predictive of post-treatment QoL is now feasible. Among patients receiving aggressive cancer treatment such as hematopoietic cell transplantation (HCT), analysis of circadian rhythms (24-hour patterns of sleep and activity) via wearable sensors is limited.Objective
To evaluate the relationship between overall QoL and circadian rhythms in patients receiving allogeneic HCT.Methods
Patients wore an ActiGraph GT3X (Pensacola, FL) activity monitor for at least 72 hours before the initiation of conditioning chemotherapy and transplantation and completed a QoL (Functional Assessment of Cancer Therapy-General [FACT-G]) assessment. QoL assessments were also completed 1, 3, and 6 months after HCT.Results
Patients (n = 45, M age = 55) were mostly male (66%) with a total FACT-G score of 80.96 (SD = 16.05) before HCT. Mixed models revealed robust cross-sectional associations between overall QoL and multiple circadian rhythmicity parameters, including durations of high physical activity, overall circadian rhythmicity, and earlier starts of daily activity (P's < .01). Recovery of QoL after transplant was predicted by longer pre-transplant durations of high physical activity (P = .04) and earlier evening retirement (P = .04).Conclusion
Our findings suggest that wearable sensor information is a promising method of predicting recovery of QoL after HCT. Additional studies are needed to confirm these findings in a larger sample. 相似文献26.
Amgad El Mekabaty Monica S. Pearl Bommy Mershon Ivor Berkowitz Philippe Gailloud Thierry A.G.M. Huisman 《Journal of neuroradiology. Journal de neuroradiologie》2019,46(3):214-221
Background and purpose
The vein of Galen aneurysmal malformation (VGAM) is a rare congenital vascular malformation with a higher morbidity and mortality, especially in neonates. Ultrasound, CT and MR are usually used in diagnosis and treatment monitoring of these disorders. In this current study, we aim to examine utility of SWI in evaluation of treatment response in infants with VGAM.Materials and methods
We performed a retrospective chart analysis of children with VGAM in our institution between January 2008 and December 2016. Inclusion criteria included; confirmed VGAM on DSA; available SWI sequence at baseline and at follow up after at least a single embolization session; age at initial MR of 18?years or younger. Signal intensity and Angioarchitecture of VGAM and cerebral veins on SWI, as well as hydrocephalus and clinical outcome were evaluated.Results
Of 11 patients identified with VGAM in our institution, 5 children (3 males and 2 females) satisfied the inclusion criteria. The average age at initial MR was 29?days (range 1–120). Fourteen MRI were available for review. All children had VGAM of mural type. Intramedullary veins were dilated and SWI-hypointense in all children, while subependymal and sulcal veins were dilated and SWI-hypointense in 4 patients on initial MRI. On the first available follow up MRI, cerebral veins have mostly normalized in 4 children and remained mostly dilated and SWI-hypointense in 1 child; even after complete treatment of the VGAM.Conclusion
Our preliminary findings show that SWI seems to offer a beneficial non-invasive tool in evaluating passive venous congestion patterns in pediatric patients with VGAM. It remains to be determined in larger studies, the clinical significance of these SWI changes. 相似文献27.
Peyman Sardari Nia Jean H.T. Daemen Jos G. Maessen 《The Journal of thoracic and cardiovascular surgery》2019,157(4):1567-1574
Objectives
The aim of this study was to develop a high-fidelity minimally invasive mitral valve surgery (MIMVS) simulator.Methods
The process of industrial serial design was applied based on pre-set requirements, acquired by interviewing experienced mitral surgeons. A thoracic torso with endoscopic and robotic access and disposable silicone mitral valve apparatus with a feedback system was developed. The feedback system was based on 4 cameras around the silicone valve and an edge detection algorithm to calculate suture depth and width. Validity of simulator measurements was assessed by comparing simulator-generated values with measurements done manually on 3-dimensional reconstructed micro-computed tomography scan of the same sutures. Independent surgeons tested the simulator between 2014 and 2018, whereupon an evaluation was done through a questionnaire.Results
The feedback system was able to provide width and depth measurements, which were subsequently scored by comparison to pre-set target values. Depth did not significantly differ between simulator and micro-computed tomography scan measurements (P = .139). Width differed significantly (P = .001), whereupon a significant regression equation was found (P < .0001) to calibrate the simulator. After calibration, no significant difference was found (P = .865). In total, 99 surgeons tested the simulator and more than agreed with the statements that the simulator is a good method for training MIMVS, and that the mitral valve and suture placement looked and felt realistic.Conclusions
We successfully developed a high-fidelity MIMVS simulator for endoscopic and robotic approaches. The simulator provides a platform to train skills in an objective and reproducible manner. Future studies are needed to provide evidence for its application in training surgeons. 相似文献28.
S. Kim M.J. Graham R.G. Lee L. Yang S. Kim V. Subramanian J.D. Layne L. Cai R.E. Temel D. Shih A.J. Lusis J.A. Berliner S. Lee 《Nutrition, metabolism, and cardiovascular diseases : NMCD》2019,29(3):306-315
Background and aims
Heparin-binding EGF-like growth factor (HB-EGF) is a representative EGF family member that interacts with EGFR under diverse stress environment. Previously, we reported that the HB-EGF-targeting using antisense oligonucleotide (ASO) effectively suppressed an aortic aneurysm in the vessel wall and circulatory lipid levels. In this study, we further examined the effects of the HB-EGF ASO administration on the development of hyperlipidemia-associated atherosclerosis using an atherogenic mouse model.Methods and results
The male and female LDLR deficient mice under Western diet containing 21% fat and 0.2% cholesterol content were cotreated with control and HB-EGF ASOs for 12 weeks. We observed that the HB-EGF ASO administration effectively downregulated circulatory VLDL- and LDL-associated lipid levels in circulation; concordantly, the HB-EGF targeting effectively suppressed the development of atherosclerosis in the aorta. An EGFR blocker BIBX1382 administration suppressed the hepatic TG secretion rate, suggesting a positive role of the HB-EGF signaling for the hepatic VLDL production. We newly observed that there was a significant improvement of the insulin sensitivity by the HB-EGF ASO administration in a mouse model under the Western diet as demonstrated by the improvement of the glucose and insulin tolerances.Conclusion
The HB-EGF ASO administration effectively downregulated circulatory lipid levels by suppressing hepatic VLDL production rate, which leads to effective protection against atherosclerosis in the vascular wall. 相似文献29.
P. Mendogni S. Henchi L.C. Morlacchi D. Tosi M. Nosotti P. Tarsia A.I. Gregorini L. Rosso 《Transplantation proceedings》2019,51(1):194-197
Background
Solid organ transplantation is associated with a higher risk of Epstein-Barr virus (EBV)–related lymphoproliferative disease due to immunosuppressive regimen. Little evidence is currently available on post-transplant lymphoproliferative disorders (PTLDs) in the lung transplant (LuTx) setting, particularly in cystic fibrosis (CF) recipients.Methods
We retrospectively analyzed all the cases of PTLDs that occurred in our LuTx center between January 2015 and December 2017. We reviewed clinical and radiologic data, donor and recipient EBV serostatus, immunosuppressive therapy, histologic data, and follow-up of these patients.Results
A total of 77 LuTxs were performed at our center in the study period; 39 (50.6%) patients had CF; 4 developed EBV-related PTLDs. They were all young (17–26 years) CF patients with high serum EBV DNA load. Disease onset was within the first 3 months after LuTx. In 3 cases presentation was associated with fever and infection-like symptoms, whereas in 1 case radiologic suspicion arose unexpectedly from a CT scan performed for different clinical reasons. Diagnosis was reached through lung biopsy in all cases. All patients received rituximab,?cyclophosphamide, doxorubicin hydrochloride (hydroxydaunomycin), vincristine sulfate (Oncovin), and prednisone with variable response and complications.Conclusion
In our experience, the early development of EBV-related PTLD was a highly aggressive, life-threatening condition, which exclusively affected young CF patients in the early post-transplant period. The rate of this complication was relatively high in our population.Diagnosis with lung biopsy is crucial in all suspected cases and regular monitoring of EBV DNA levels is of utmost importance given the high correlation with PTLDs in patients at increased risk. 相似文献30.
Neuroinflammation is initiated as a result of traumatic brain injury and can exacerbate evolving tissue pathology. Immune cells respond to acute signals from damaged cells, initiate neuroinflammation, and drive the pathological consequences over time. Importantly, the mechanism(s) of injury, the location of the immune cells within the brain, and the animal species all contribute to immune cell behavior following traumatic brain injury. Understanding the signals that initiate neuroinflammation and the context in which they appear may be critical for understanding immune cell contributions to pathology and regeneration.Within this paper, we review a number of factors that could affect immune cell behavior acutely following traumatic brain injury. 相似文献