全文获取类型
收费全文 | 2122篇 |
免费 | 171篇 |
国内免费 | 3篇 |
专业分类
耳鼻咽喉 | 15篇 |
儿科学 | 59篇 |
妇产科学 | 80篇 |
基础医学 | 377篇 |
口腔科学 | 38篇 |
临床医学 | 181篇 |
内科学 | 475篇 |
皮肤病学 | 111篇 |
神经病学 | 96篇 |
特种医学 | 58篇 |
外科学 | 316篇 |
综合类 | 7篇 |
一般理论 | 3篇 |
预防医学 | 152篇 |
眼科学 | 88篇 |
药学 | 57篇 |
中国医学 | 1篇 |
肿瘤学 | 182篇 |
出版年
2022年 | 29篇 |
2021年 | 43篇 |
2020年 | 15篇 |
2019年 | 40篇 |
2018年 | 66篇 |
2017年 | 42篇 |
2016年 | 29篇 |
2015年 | 54篇 |
2014年 | 72篇 |
2013年 | 71篇 |
2012年 | 132篇 |
2011年 | 117篇 |
2010年 | 65篇 |
2009年 | 51篇 |
2008年 | 113篇 |
2007年 | 129篇 |
2006年 | 91篇 |
2005年 | 113篇 |
2004年 | 93篇 |
2003年 | 99篇 |
2002年 | 87篇 |
2001年 | 54篇 |
2000年 | 78篇 |
1999年 | 41篇 |
1998年 | 27篇 |
1997年 | 16篇 |
1996年 | 22篇 |
1995年 | 17篇 |
1994年 | 13篇 |
1993年 | 15篇 |
1992年 | 36篇 |
1991年 | 53篇 |
1990年 | 50篇 |
1989年 | 45篇 |
1988年 | 32篇 |
1987年 | 26篇 |
1986年 | 28篇 |
1985年 | 28篇 |
1984年 | 14篇 |
1983年 | 13篇 |
1982年 | 13篇 |
1979年 | 8篇 |
1978年 | 10篇 |
1977年 | 13篇 |
1976年 | 9篇 |
1975年 | 13篇 |
1973年 | 10篇 |
1972年 | 8篇 |
1971年 | 7篇 |
1970年 | 9篇 |
排序方式: 共有2296条查询结果,搜索用时 0 毫秒
91.
James R. Pinney Kim T. Du Perla Ayala Qizhi Fang Richard E. Sievers Patrick Chew Lawrence Delrosario Randall J. Lee Tejal A. Desai 《Biomaterials》2014
Chronic fibrosis caused by acute myocardial infarction (MI) leads to increased morbidity and mortality due to cardiac dysfunction. We have developed a therapeutic materials strategy that aims to mitigate myocardial fibrosis by utilizing injectable polymeric microstructures to mechanically alter the microenvironment. Polymeric microstructures were fabricated using photolithographic techniques and studied in a three-dimensional culture model of the fibrotic environment and by direct injection into the infarct zone of adult rats. Here, we show dose-dependent down-regulation of expression of genes associated with the mechanical fibrotic response in the presence of microstructures. Injection of this microstructured material into the infarct zone decreased levels of collagen and TGF-β, increased elastin deposition and vascularization in the infarcted region, and improved functional outcomes after six weeks. Our results demonstrate the efficacy of these discrete anti-fibrotic microstructures and suggest a potential therapeutic materials approach for combatting pathologic fibrosis. 相似文献
92.
Ekene Okoye Eunice K Choi Mukul Divatia Brian J Miles Alberto G Ayala Jae Y Ro 《International journal of clinical and experimental pathology》2014,7(12):9061-9066
Neuroendocrine (NE) differentiation in prostate carcinomas can be seen in two settings: as a focal finding in conventional acinar adenocarcinoma, identifiable by immunohistochemical staining, or as a primary NE tumor of the prostate gland, such as carcinoid, small cell carcinoma, or large cell NE carcinoma. Of particular interest is the large cell NE carcinoma, which had been previously reported in isolated cases or in limited case series. In this report, we describe a case of a large cell NE carcinoma diagnosed in a 48-year-old man who presented with difficulty in voiding and urine retention. A cystoscopy revealed an enlarged, elongated prostate with an intra-urethral obstructing mass in the prostatic urethra. Subsequently, a transurethral resection of prostate (TURP) was performed at an outside hospital under the clinical diagnosis of benign prostatic hyperplasia (BPH). Microscopic examination of the TURP specimen revealed several foci of low-grade transitional-zone-type adenocarcinoma corresponding to Gleason score 5 (3 + 2), and a focus of high-grade large cell NE carcinoma. Concurrent x-ray computed tomography scans of the chest, abdomen, and pelvis demonstrated an enlarged left pelvic lymph node, which was biopsied and the patient was diagnosed with metastatic large cell NE carcinoma. He subsequently underwent 8 cycles of neoadjuvant chemotherapy with Lupron, a laparoscopic robotic-assisted radical retropubic prostatectomy, and pelvic lymphadenectomy. He died of widely metastatic prostatic carcinoma with leptomeningeal metastases 13 months after radical prostatectomy. Here, we present a rare case of large cell NE carcinoma with a review of the published literature. 相似文献
93.
Kosuke Miyai Mukul K Divatia Steven S Shen Brian J Miles Alberto G Ayala Jae Y Ro 《International journal of clinical and experimental pathology》2014,7(5):2518-2526
Intraductal carcinoma of the prostate (IDC-P) has been described as a lesion associated with intraductal spread of invasive carcinoma and consequently aggressive disease. However, there are a few reported cases of pure IDC-P without an associated invasive component, strongly suggesting that this subset of IDC-P may represent a precursor lesion. We compared the clinicopathological features between the morphologically “regular type” IDC-P and “precursor-like” IDC-P. IDC-P was defined as follows; 1) solid/dense cribriform lesions or 2) loose cribriform/micropapillary lesions with prominent nuclear pleomorphism and/or non-focal comedonecrosis. We defined precursor-like IDC-P as follows; 1) IDC-P without adjoining invasive adenocarcinoma but carcinoma present distant from the IDC-P or 2) IDC-P having adjoining invasive microcarcinoma (less than 0.05 ml) and showing a morphologic transition from high-grade prostatic intraepithelial neoplasia (HGPIN) to the IDC-P. IDC-P lacking the features of precursor-like IDC-P was categorized as regular type IDC-P. Of 901 radical prostatectomies performed at our hospital, 141 and 14 showed regular type IDC-P and precursor-like IDC-P in whole-mounted specimens, respectively. Regular type IDC-P cases had significantly higher Gleason score, more frequent extraprostatic extension and seminal vesicle invasion, more advanced pathological T stage, and lower 5-year biochemical recurrence-free rate than precursor-like IDC-P cases. Multivariate analysis revealed nodal metastasis and the presence of regular type IDC-P as independent predictors for biochemical recurrence. Our data suggest that IDC-P may be heterogeneous with variable clinicopathological features. We also suggest that not all IDC-P cases represent intraductal spread of pre-existing invasive cancer, and a subset of IDC-P may be a precursor lesion. 相似文献
94.
David G. Birch Lassana Samarakoon Michele Melia Jacque L. Duncan Allison R. Ayala Isabelle Audo Janet K. Cheetham Todd A. Durham Alessandro Iannaccone Mark E. Pennesi Katarina Stingl for the Foundation Fighting Blindness Consortium Investigator Group 《Investigative ophthalmology & visual science》2022,63(3)
PurposeTo measure visual fields using two-color dark-adapted chromatic perimetry in a subset of participants in the Rate of Progression of USH2A-related Retinal Degeneration (RUSH2A), a study of USH2A-mediated syndromic (USH2) and autosomal recessive nonsyndromic retinitis pigmentosa, determine percentage retaining rod function, and explore relationships between dark-adapted visual fields (DAVF) and rod function from ERG and full-field stimulus thresholds (FST).MethodsFull-field rod mean sensitivity, number of rod loci, maximum sensitivity, DAVF full-field hill of vision (DAVF VTOT), and 30° hill of vision (DAVF V30) were measured in one eye for DAVF ancillary study participants (n = 49). Loci where cyan relative to red sensitivity was more than 5 dB on dark-adapted chromatic perimetry were considered rod mediated. Correlation coefficients between the DAVF measures and standard clinical measures were estimated, as were kappa statistics (κ) for agreement between DAVF and other measures of rod function.ResultsOf 49 participants tested with DAVF, 38 (78%) had evidence of rod function, whereas 15 (31%) had measurable rod ERGs. DAVF maximum sensitivity was highly correlated with FST white thresholds (r = −0.80; P < .001). Although not statistically significant, the number of rod loci and DAVF VTOT were lower in eyes with longer disease duration by 0.82 (95% confidence interval, −1.76, 0.12) loci/year and 0.59 (95% confidence interval, −1.82, 0.64) dB-steradians/year, respectively.ConclusionsRod-mediated function on FST and DAVF is present in many patients with symptomatic USH2A-related retinal degeneration, including some without measurable rod ERGs. RUSH2A longitudinal data will determine how these measures change with disease progression and whether they are useful for longitudinal studies in inherited retinal degenerations. 相似文献
95.
Ayala Tovy Carina Rosas Amos S. Gaikwad Geraldo Medrano Linda Zhang Jaime M. Reyes Yung-Hsin Huang Tatsuhiko Arakawa Kristen Kurtz Shannon E. Conneely Anna G. Guzman Rogelio Aguilar Anne Gao Chun-Wei Chen Jean J. Kim Melissa T. Carter Amaia Lasa-Aranzasti Irene Valenzuela Lionel Van Maldergem Lorenzo Brunetti M. John Hicks Andrea N. Marcogliese Margaret A. Goodell Rachel E. Rau 《Haematologica》2022,107(4):887
Tatton-Brown-Rahman syndrome (TBRS) is an overgrowth disorder caused by germline heterozygous mutations in the DNA methyltransferase DNMT3A. DNMT3A is a critical regulator of hematopoietic stem cell (HSC) differentiation and somatic DNMT3A mutations are frequent in hematologic malignancies and clonal hematopoiesis. Yet, the impact of constitutive DNMT3A mutation on hematopoiesis in TBRS is undefined. In order to establish how constitutive mutation of DNMT3A impacts blood development in TBRS we gathered clinical data and analyzed blood parameters in 18 individuals with TBRS. We also determined the distribution of major peripheral blood cell lineages by flow cytometric analyses. Our analyses revealed non-anemic macrocytosis, a relative decrease in lymphocytes and increase in neutrophils in TBRS individuals compared to unaffected controls. We were able to recapitulate these hematologic phenotypes in multiple murine models of TBRS and identified rare hematological and non-hematological malignancies associated with constitutive Dnmt3a mutation. We further show that loss of DNMT3A in TBRS is associated with an altered DNA methylation landscape in hematopoietic cells affecting regions critical to stem cell function and tumorigenesis. Overall, our data identify key hematopoietic effects driven by DNMT3A mutation with clinical implications for individuals with TBRS and DNMT3A-associated clonal hematopoiesis or malignancies. 相似文献
96.
Federico Pappalardo Evgenij Potapov Antonio Loforte Michiel Morshuis David Schibilsky Daniel Zimpfer Julia Riebandt Christian Etz Matteo Attisani Mauro Rinaldi Assad Haneya Faiz Ramjankhan Dirk Donker Ulrich P Jorde Daniel Lewin Radi Wieloch Rafael Ayala Jochen Cremer Letizia Bertoldi Michael Borger Artur Lichtenberg Jan Gummert Diyar Saeed the Durable MCS after ECLS study group 《Interactive Cardiovascular and Thoracic Surgery》2022,34(4):676
Open in a separate window OBJECTIVESImplanting a durable left ventricular assist device (LVAD) in a patient on extracorporeal life support (ECLS) is challenging. The goal of this study was to compare the results of patients from a European registry who had a durable LVAD implanted with or without transition from ECLS to cardiopulmonary bypass (CPB).METHODSA total of 531 patients on ECLS support who had an LVAD implant between January 2010 and August 2018 were analysed; after 1:1 propensity score matching, we identified and compared 175 patients in each group.RESULTSThe duration of preoperative ECLS was 7 [standard deviation (SD) 6] vs 7 (SD 6) days in patients with or without CPB (P = 0.984). The surgical time was longer in the CPB group [285 (SD 72) vs 209 [SD 75] min; P ≤ 0.001). The postoperative chest tube output was comparable [1513 (SD 1311) vs 1390 (SD 1121) ml; P = 0.3]. However, re-exploration for bleeding was necessary in 41% vs 29% of patients with or without CPB (P = 0.01) and a significantly higher number of packed red blood cells and fresh frozen plasma [8 (SD 8) vs 6 (SD 4) units; P = 0.001 and 6 (SD 7) vs 5 (SD 5) units; P = 0.03] were administered to patients operated on with CPB. A postoperative mechanical right ventricular support device was necessary in 50% vs 41% of patients (P = 0.08). The stroke rate was not significantly different (P 0.99). No difference in survival was observed.CONCLUSIONSOmitting CPB for an LVAD implant in patients on ECLS is safe and results in shorter operating time, less re-exploration for bleeding and fewer blood products. However, no survival benefit is observed. 相似文献
97.
98.
99.
Melatonin inhibits nuclear factor kappa B activation and oxidative stress and protects against thioacetamide induced liver damage in rats 总被引:10,自引:0,他引:10
Bruck R Aeed H Avni Y Shirin H Matas Z Shahmurov M Avinoach I Zozulya G Weizman N Hochman A 《Journal of hepatology》2004,40(1):86-93
BACKGROUND/AIMS: Free radical-mediated oxidative stress has been implicated in the pathogenesis of acute liver injury. The aim of our study was to investigate whether melatonin, a potent free radical scavenger could prevent fulminant hepatic failure in rats. METHODS: Liver damage was induced by two consecutive injections of thioacetamide (TAA, 300 mg/kg/i.p.) at 24 h intervals. Treatment with melatonin (3 mg/kg/daily, i.p) was initiated 24 h prior to TAA. RESULTS: Twenty-four h after the second TAA injection, serum liver enzymes and blood ammonia were lower in rats treated with TAA+melatonin compared to TAA (P<0.001). Liver histology was significantly improved and the mortality in the melatonin-treated rats was decreased (P<0.001). The increased nuclear binding of nuclear factor kappa B in the livers of the TAA-treated rats, was inhibited by melatonin. The hepatic levels of thiobarbituric acid reactive substances, protein carbonyls and inducible nitric oxide synthase were lower in the TAA+melatonin-treated group (P<0.01), indicating decreased oxidative stress and inflammation. CONCLUSIONS: In a rat model of TAA-induced fulminant hepatic failure, melatonin improves survival and reduces liver damage and oxidative stress. The results suggest a causative role of oxidative stress in TAA-induced hepatic damage and suggest that melatonin may be utilized to reduce liver injury associated with oxidative stress. 相似文献
100.