全文获取类型
| 收费全文 | 2717338篇 |
| 免费 | 193802篇 |
| 国内免费 | 7961篇 |
专业分类
| 耳鼻咽喉 | 36223篇 |
| 儿科学 | 88899篇 |
| 妇产科学 | 74105篇 |
| 基础医学 | 380762篇 |
| 口腔科学 | 72624篇 |
| 临床医学 | 247464篇 |
| 内科学 | 542153篇 |
| 皮肤病学 | 64550篇 |
| 神经病学 | 226866篇 |
| 特种医学 | 104320篇 |
| 外国民族医学 | 747篇 |
| 外科学 | 405174篇 |
| 综合类 | 52138篇 |
| 现状与发展 | 8篇 |
| 一般理论 | 1118篇 |
| 预防医学 | 206145篇 |
| 眼科学 | 60316篇 |
| 药学 | 196702篇 |
| 9篇 | |
| 中国医学 | 5500篇 |
| 肿瘤学 | 153278篇 |
出版年
| 2021年 | 22010篇 |
| 2019年 | 22624篇 |
| 2018年 | 31640篇 |
| 2017年 | 24312篇 |
| 2016年 | 28160篇 |
| 2015年 | 31886篇 |
| 2014年 | 44013篇 |
| 2013年 | 66239篇 |
| 2012年 | 88226篇 |
| 2011年 | 93202篇 |
| 2010年 | 55991篇 |
| 2009年 | 53709篇 |
| 2008年 | 87413篇 |
| 2007年 | 92824篇 |
| 2006年 | 94207篇 |
| 2005年 | 90758篇 |
| 2004年 | 87346篇 |
| 2003年 | 84269篇 |
| 2002年 | 81199篇 |
| 2001年 | 129494篇 |
| 2000年 | 132122篇 |
| 1999年 | 111623篇 |
| 1998年 | 32967篇 |
| 1997年 | 29387篇 |
| 1996年 | 29448篇 |
| 1995年 | 28473篇 |
| 1994年 | 26079篇 |
| 1993年 | 24397篇 |
| 1992年 | 85866篇 |
| 1991年 | 82202篇 |
| 1990年 | 79351篇 |
| 1989年 | 76638篇 |
| 1988年 | 70027篇 |
| 1987年 | 68454篇 |
| 1986年 | 64100篇 |
| 1985年 | 61129篇 |
| 1984年 | 45813篇 |
| 1983年 | 38795篇 |
| 1982年 | 23650篇 |
| 1981年 | 21126篇 |
| 1979年 | 39572篇 |
| 1978年 | 28108篇 |
| 1977年 | 23828篇 |
| 1976年 | 22024篇 |
| 1975年 | 23247篇 |
| 1974年 | 27227篇 |
| 1973年 | 25730篇 |
| 1972年 | 24048篇 |
| 1971年 | 22161篇 |
| 1970年 | 20359篇 |
排序方式： 共有10000条查询结果，搜索用时 15 毫秒
41.
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42.
43.
Katherine M. Stenson Benjamin O. Patterson Matthew Joe Grima Jorg L. De Bruin Peter J.E. Holt Ian Loftus 《Journal of vascular surgery》2019,69(1):53-62.e1
Background
Endovascular aneurysm sealing (EVAS) represents a novel approach to the treatment of abdominal aortic aneurysms. It uses polymer technology to achieve an anatomic seal within the sac of the aneurysm. This cohort study reports the early clinical outcomes, technical refinements, and learning curve during the initial EVAS experience at a single institution.Methods
Results from 150 consecutive EVAS cases for intact, infrarenal abdominal aortic aneurysms are reported here. These cases were undertaken between March 2013 and July 2015. Preoperative, perioperative, and postoperative data were collected for each patient prospectively.Results
The median age of the cohort was 76.6 years (interquartile range, 70.2-80.9 years), and 87.3% were male. Median aneurysm diameter was 62.0 mm (IQR, 58.0-69.0 mm). Adverse neck morphology was seen in 69 (46.0%) patients, including aneurysm neck length <10 mm (17.3%), neck diameter >32 mm or <18 mm (8.7%), and neck angulation >60 degrees (15.3%). Median follow-up was 687 days (IQR, 463-897 days); 37 patients (24.7%) underwent reintervention. The rates of unresolved endoleak are 1.3% type IA, 0.7% type IB, and 2.7% type I. There were no type III endoleaks. There have been seven secondary ruptures in this cohort; all but one of these patients survived after reintervention. Only one rupture occurred in an aneurysm that had been treated within the manufacturer's instructions for use (IFU).Conclusions
The rate of unresolved endoleaks is satisfactorily low. The incidence of secondary rupture is of concern; however, when the IFU are adhered to, the rate is very low. The results of this study suggest that working within the IFU yields better clinical results. 相似文献44.
David C. Johnson Steven S. Raman Sohrab A. Mirak Lorna Kwan Amirhossein M. Bajgiran William Hsu Cleo K. Maehara Preeti Ahuja Izak Faiena Aydin Pooli Amirali Salmasi Anthony Sisk Ely R. Felker David S.K. Lu Robert E. Reiter 《European urology》2019,75(5):712-720
Background
Multiparametric magnetic resonance imaging (mpMRI) undoubtedly affects the diagnosis and treatment of localized prostate cancer (CaP). However, clinicians need a better understanding of its accuracy and limitations in detecting individual CaP foci to optimize management.Objective
To determine the per-lesion detection rate for CaP foci by mpMRI and identify predictors of tumor detection.Design, setting, and participants
We carried out a retrospective analysis of a prospectively managed database correlating lesion-specific results from mpMRI co-registered with whole-mount pathology (WMP) prostatectomy specimens from June 2010 to February 2018. Participants include 588 consecutive patients with biopsy-proven CaP undergoing 3-T mpMRI before radical prostatectomy at a single tertiary institution.Outcome measurements and statistical analysis
We measured mpMRI sensitivity in detecting individual CaP and clinically significant (any Gleason score ≥7) CaP foci and predictors of tumor detection using multivariate analysis.Results and limitations
The final analysis included 1213 pathologically confirmed tumor foci in 588 patients with primarily intermediate- (75%) or high-risk (12%) CaP. mpMRI detected 45% of all lesions (95% confidence interval [CI] 42–47%), including 65% of clinically significant lesions (95% CI 61–69%) and nearly 80% of high-grade tumors. Some 74% and 31% of missed solitary and multifocal tumors, respectively, were clinically significant. The majority of missed lesions were small (61.1% ≤1 cm); 28.3% were between 1 and 2 cm, and 10.4% were >2 cm. mpMRI missed at least one clinically significant focus in 34% of patients overall, and in 45% of men with multifocal lesions. On multivariate analysis, smaller, low-grade, multifocal, nonindex tumors with lower prostate-specific antigen density were more likely to be missed. Limitations include selection bias in a prostatectomy cohort, lack of specificity data, an imperfect co-registration process, and uncertain clinical significance for undetected lesions.Conclusions
mpMRI detects less than half of all and less than two-thirds of clinically significant CaP foci. The moderate per-lesion sensitivity and significant proportion of men with undetected tumor foci demonstrate the current limitations of mpMRI.Patient summary
Magnetic resonance imaging of the prostate before surgical removal for prostate cancer finds less than half of all individual prostate cancer tumors. Large, solitary, aggressive tumors are more likely to be visualized on imaging. 相似文献45.
46.
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47.
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48.
S. Fatahi M. Pezeshki S.M. Mousavi A. Teymouri J. Rahmani H. Kord Varkaneh E. Ghaedi 《Nutrition, metabolism, and cardiovascular diseases : NMCD》2019,29(5):432-439
Background and aim
Given the contradictory results of previous randomized controlled trials (RCTs), we performed a systematic review and meta-analysis to quantify and summarize the effects of folic acid supplementation on C-reactive protein (CRP).Methods and results
We performed a systematic search of all available RCTs conducted up to October 2018 in the following databases: PubMed, Scopus, and Cochrane. RCTs that investigated the effect of folate on CRP were included in the present study. Data were combined with the use of generic inverse-variance random-effects models. Statistical heterogeneity between studies was evaluated using Cochran's Q-test. Ten RCTs (1179 subjects) were included in the present meta-analysis. Pooled analysis results showed that folate supplementation significantly lowered the serum CRP level (weighted mean difference (WMD): ?0.685 mg/l, 95% CI: ?1.053, ?0.318, p < 0.001). However, heterogeneity was significant (I2 = 96.7%, p = 0.000). Stratified analyses indicated that sex, intervention period, and type of study population were sources of heterogeneity. Following analysis, results revealed that the greatest impact was observed in women (WMD: ?0.967 mg/l, 95% CI: ?1.101, ?0.833, p = 0.000), patients with type 2 diabetes mellitus (WMD: ?1.764 mg/l, 95% CI: ?2.002, ?1.526, p = 0.000), and intervention period less than 12 weeks (WMD: ?0.742 mg/l, 95% CI: ?0.834, ?0.650, p = 0.000).Conclusion
This meta-analysis suggested that folic acid supplementation could significantly lower the serum CRP level. Folic acid leads to greater CRP lowering effect in women, patients with T2DM, and those with less than 12-week intervention. 相似文献49.
M. Iachina P.M. Ljungdalh R.G. Sørensen L. Kaerlev J. Blaakær O. Trosko N. Qvist B.M. Nørgård 《Clinical oncology (Royal College of Radiologists (Great Britain))》2019,31(2):115-123
Aims
To examine the influence of pre-existing psychiatric disorder on the choice of treatment in patients with gynaecological cancer.Materials and methods
The analyses were based on all patients who underwent surgical treatment for endometrial, ovarian or cervical cancer who were registered in the Danish Gynecological Cancer Database in the years 2007–2014 (3059 patients with ovarian cancer, 5100 patients with endometrial cancer and 1150 with cervical cancer). Logistic regression model and Cox regression model, adjusted for relevant confounders, were used to estimate the effect of pre-existing psychiatric disorder on the course of cancer treatment. Our outcomes were (i) presurgical oncological treatment, (ii) macroradical surgery for patients with ovarian cancer, (iii) radiation/chemotherapy within 30 days and 100 days after surgery and (iv) time from surgery to first oncological treatment.Results
In the group of patients with ovarian cancer, more patients with a psychiatric disorder received macroradical surgery versus patients without a psychiatric disorder, corresponding to an adjusted odds ratio of 1.24 (95% confidence interval 0.62–2.41) and the chance for having oncological treatment within 100 days was odds ratio = 1.26 (95% confidence interval 0.77–2.10). As for patients with endometrial cancer, all outcome estimates were close to unity. The adjusted odds ratio for oncological treatment within 30 days after surgery in patients with cervical cancer with a history of psychiatric disorder was 0.20 (95% confidence interval 0.03–1.54).Conclusions
We did not find any significant differences in the treatment of ovarian and endometrial cancer in patients with pre-existing psychiatric diagnoses. When it comes to oncological treatment, we suggest that increased attention should be paid to patients with cervical cancer having a pre-existing psychiatric diagnosis. 相似文献50.
Shulin Wu Sharron X. Lin Gregory J. Wirth Min Lu Jian Lu Alexander O. Subtelny Zongwei Wang Douglas M. Dahl Aria F. Olumi Chin-Lee Wu 《Clinical genitourinary cancer》2019,17(1):e44-e52