全文获取类型
收费全文 | 2637篇 |
免费 | 189篇 |
国内免费 | 25篇 |
专业分类
耳鼻咽喉 | 12篇 |
儿科学 | 66篇 |
妇产科学 | 111篇 |
基础医学 | 348篇 |
口腔科学 | 72篇 |
临床医学 | 267篇 |
内科学 | 637篇 |
皮肤病学 | 71篇 |
神经病学 | 177篇 |
特种医学 | 81篇 |
外科学 | 276篇 |
综合类 | 28篇 |
一般理论 | 1篇 |
预防医学 | 172篇 |
眼科学 | 87篇 |
药学 | 162篇 |
中国医学 | 14篇 |
肿瘤学 | 269篇 |
出版年
2024年 | 5篇 |
2023年 | 55篇 |
2022年 | 87篇 |
2021年 | 160篇 |
2020年 | 99篇 |
2019年 | 117篇 |
2018年 | 118篇 |
2017年 | 66篇 |
2016年 | 114篇 |
2015年 | 109篇 |
2014年 | 134篇 |
2013年 | 172篇 |
2012年 | 260篇 |
2011年 | 212篇 |
2010年 | 127篇 |
2009年 | 98篇 |
2008年 | 143篇 |
2007年 | 140篇 |
2006年 | 115篇 |
2005年 | 114篇 |
2004年 | 90篇 |
2003年 | 78篇 |
2002年 | 71篇 |
2001年 | 15篇 |
2000年 | 8篇 |
1999年 | 9篇 |
1998年 | 14篇 |
1997年 | 5篇 |
1996年 | 3篇 |
1995年 | 4篇 |
1994年 | 11篇 |
1993年 | 6篇 |
1992年 | 12篇 |
1991年 | 9篇 |
1990年 | 9篇 |
1989年 | 3篇 |
1988年 | 8篇 |
1987年 | 8篇 |
1986年 | 7篇 |
1985年 | 8篇 |
1984年 | 2篇 |
1983年 | 2篇 |
1982年 | 4篇 |
1981年 | 2篇 |
1979年 | 3篇 |
1978年 | 4篇 |
1977年 | 2篇 |
1974年 | 5篇 |
1971年 | 1篇 |
1965年 | 1篇 |
排序方式: 共有2851条查询结果,搜索用时 15 毫秒
981.
Gallagher MM Yap YG Padula M Ward DE Rowland E Camm AJ 《International journal of cardiology》2008,127(3):307-312
Urocortins, a novel member of the corticotrophin-releasing factor (CRF) family, have been shown in animal and human studies to possess several beneficial effects in stress, cardiovascular and renal function, and inflammatory responses via CRF receptors. In the heart, urocortins have been demonstrated to produce cardioprotective effects during ischemia and reperfusion injury. Urocortins have also exerted effects on hemodynamic, endocrine and renal parameters in experimental animal heart failure models. In humans, plasma urocortin levels have been shown to significantly increase in systolic heart failure patients. This growing evidence suggests that urocortins may have a prognostic value as well as being a potential therapeutic treatment for heart failure and myocardial infarction patients. Currently, only a few clinical studies on urocortins are available. In this review article, the role of urocortins in the heart has been summarized. Their possible beneficial roles in heart failure and myocardial infarction have been discussed, based on relevant published articles from both basic and clinical studies available to date. 相似文献
982.
983.
Deguchi M Kishino J Hattori M Furue Y Yamamoto M Mochizuki I Iguchi M Hirano Y Hojou K Nagira M Nishitani Y Okazaki K Yasui K Arimura A 《European journal of pharmacology》2008,601(1-3):163-170
We discovered a novel dihydroorotate dehydrogenase (DHO-DH) inhibitor, S-2678 ([2-fluoro-2',5'-dimethyl-4'-[6-(3-methyl-2-butenyloxy) pyridin-3-yl] biphenyl-4-yl]-(3-methyl-2-butenyl) amine). Its inhibitory activity against DHO-DH was more potent than that of A77 1726, an active metabolite of the anti-rheumatic drug leflunomide. S-2678 suppressed immunoglobulin production in mouse B cells and human peripheral blood mononuclear cells in vitro, with little or no inhibition of cell proliferation, probably through inhibition of class switch recombination in the immunoglobulin heavy chain loci in B cells. In vivo antibody production induced by systemic immunization with ovalbumin was dramatically suppressed by oral administration of S-2678, without any toxicological signs. However, S-2678 did not affect T-cell activation in vitro, and cytokine production induced by intravenous anti-CD3 antibody in mice. S-2678 did not affect host defense in a mouse model of Candida infection, whereas leflunomide severely impaired it. In conclusion, S-2678 selectively acts on B cells, resulting in antibody production, which suggests that it is useful for the treatment of humoral immunity-related diseases. 相似文献
984.
Choi M Cho WS Han BS Cho M Kim SY Yi JY Ahn B Kim SH Jeong J 《Toxicology letters》2008,182(1-3):97-101
In order to evaluate the degree of pulmonary fibrosis and to identify the fibrogenic mechanisms induced by ultrafine amorphous silica (UFAS), UFAS suspensions ( approximately 50microl) were instilled intratracheally into A/J mice at doses of 0, 2, 10 and 50mg/kg (n=5 per group). Mice were sacrificed at 24h, 1, 4 and 14 weeks after exposure. Gomori's trichrome staining revealed that UFAS induced severe alveolar epithelial thickening and pulmonary fibrosis at 1 week, though animals almost recovered at 4 and 14 weeks. The mRNA and protein levels of cytokines (IL-4, IL-10, IL-13 and IFN-gamma), matrix metalloproteinases (MMP-2, MMP-9 and MMP-10) and tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) in lung tissues were significantly elevated at 24h and 1week post-treatment, though these levels decreased to near the control range at 4 and 14 weeks except IFN-gamma and MMP-2. These results demonstrate that UFAS can induce pulmonary fibrosis in the same way as crystalline silica. However, the degree of fibrosis observed was transient. This study shows that cytokines (IL-4, IL-10, IL-13 and IFN-gamma), MMPs (MMP-2, MMP-9 and MMP-10) and TIMP-1 play important roles in the fibrosis induced by the intratracheal instillation of UFAS. 相似文献
985.
Salaroli R Russo A Ceccarelli C Mina GD Arcella A Martinelli GN Giangaspero F Capranico G Cenacchi G 《Ultrastructural pathology》2007,31(1):33-44
Gene mutations impairing the functions of the WNT signaling transduction pathway have been found in approximately 15% of human sporadic medulloblastomas. To understand the functional role of the WNT pathway in medulloblastoma, we have investigated the intracellular distribution of β-catenin in a series of 17 human medulloblastomas to correlate such expression with neuronal differentiation and in cultured cell models following functional silencing of the APC gene by small-interference RNA (siRNA). Transient siRNA transfection resulted in a 50% reduction of the APC gene product levels in both DAOY and D283MED cell lines. In the former, less-differentiated cell line, β-catenin levels remained unchanged or were slightly reduced, but β-catenin translocated in the nucleus following APC gene siRNA silencing. In contrast, in the more differentiated D283MED cells, β-catenin levels increased about twofold while mainly maintaining the cytoplasmic and cell membrane localization. Cytoplasmic/nuclear localization of β-catenin was present in 12 of 17 cases of medulloblastoma with a prevalent distribution in the classic, 6/7 cases, and large cell/anaplastic variant, 4/4 cases. The nodular/desmoplastic lesions showed strongly positivity in the cell membrane mainly of intranodular cells with advanced neuronal differentiation. These observations support an important functional role of WNT/β-catenin pathway in neuronal differentiation in medulloblastoma. 相似文献
986.
Taylor R. Cushman Bernard Jones David Akhavan Chad G. Rusthoven Vivek Verma Ravi Salgia Mina Sedrak Erminia Massarelli James W. Welsh Arya Amini 《Clinical lung cancer》2021,22(1):e84-e97
BackgroundThe purpose of this study was to determine the effects of time from diagnosis to treatment (TTI) on survival in patients with nonmetastatic non–small-cell lung cancer (NSCLC).Materials and MethodsThe National Cancer Database was queried for patients with stages 1 to 3 NSCLC between 2004 and 2013. Patients with missing survival status/time, unknown TTI, or receipt of palliative therapy were excluded. Multivariable Cox proportional hazards modeling, logistic regression, and recursive partitioning analysis were performed to determine associated variables and survival outcomes.ResultsAltogether, 1,393,232 patients met inclusion criteria. The median follow-up was 36 months. The median TTI increased between 2004 and 2013 from 35 to 39 days (P < .001). On multivariable Cox proportional hazards modeling, TTI groups 31 to 60 days, 61 to 90 days, and > 90 days were independently related to poorer overall survival (OS) compared with TTI 1 to 30 days (hazard ratio, 1.04, 1.10, and 1.14; 95% confidence interval [CI], 1.02-1.06, 1.07-1.12, and 1.11-1.17, respectively; P < .001 for all). Recursive partitioning analysis revealed that TTI of ≤ 45 days was the most optimal threshold for survival (P < .001); patients with TTI ≤ 45 days had a median OS of 70.2 months (95% CI, 69.3-71.1 months) versus 61.5 months (95% CI, 60.5-62.4) (P < .001). There were significant disparities by age, race, ethnicity, and income for delayed (> 45 days) TTI (P < .001 for all). Subgroup analysis revealed that stage 1 and 2 patients with TTI > 45 days had a higher risk of mortality compared with TTI ≤ 45 days (hazard ratio, 1.15 and 1.05; 95% CI, 1.12-1.17 and 1.01-1.09, respectively) (P < .001).ConclusionsIncreased TTI is independently associated with poorer survival in non-metastatic NSCLC. TTI ≤ 45 days is a clinically targetable time frame associated with improved outcomes and ought to be considered for patients with lung cancer undergoing definitive therapy. 相似文献
987.
988.
Amir Mehdi Ashrafzade Mohammad Ali Sadighi Gilani Tohid Rezaei Topraggaleh Mina Khojasteh Mehdi Sepidarkish Parinaz Borjian Boroujeni Mohammad Reza Zamanian 《Andrologia》2020,52(9):e13598
Varicocele is associated with excessive production of reactive oxygen species (ROS). Although the harmful effects of ROS on sperm DNA, proteins and lipids are well documented, its impact on the expression of miRNAs in spermatozoa has not been fully understood. In this study, the expression patterns of microRNAs (miRNAs), miR-21, miR-34a and miR-122a as well as the level of ROS in the fertile control (FC; proven fertility without varicocele, n = 15) and grade III varicocele patients with normal (VN; n = 15) and abnormal (VA; n = 15) spermogram were investigated. The real-time PCR was performed to analyse the expression of the miRNAs, while oxidative stress was evaluated by measuring the concentrations of MDA. Our results showed that the expression levels of miR-21 (p = .001), miR-34a, (p = .007) and miR-122a (p < .001) were significantly decreased in spermatozoa of VN and VA patients in comparison with the fertile group. Also, increased levels of oxidative stress were detected in semen samples of varicocele patients compared with the fertile control (p < .0001). Overall, these findings demonstrate oxidative stress changes the expression pattern of some miRNAs, and these alterations could be a valuable diagnostic marker for the diagnosis and prognosis of varicocele-induced oxidative stress to retain the male fertility during the spermatogenesis process. 相似文献
989.
Helen L. Wu Whitney C. Weber Christine Shriver-Munsch Tonya Swanson Mina Northrup Heidi Price Kimberly Armantrout Mitchell Robertson-LeVay Jason S. Reed Katherine B. Bateman Eisa Mahyari Archana Thomas Stephanie L. Junell Theodore R. Hobbs Lauren D. Martin Rhonda MacAllister Benjamin N. Bimber Mark K. Slifka Alfred W. Legasse Cassandra Moats Michael K. Axthelm Jeremy Smedley Anne D. Lewis Lois Colgin Gabrielle Meyers Richard T. Maziarz Benjamin J. Burwitz Jeffrey J. Stanton Jonah B. Sacha 《Xenotransplantation》2020,27(4):e12578
Allogeneic hematopoietic stem cell transplantation (HSCT) and xenotransplantation are accompanied by viral reactivations and virus-associated complications resulting from immune deficiency. Here, in a Mauritian cynomolgus macaque model of fully MHC-matched allogeneic HSCT, we report reactivations of cynomolgus polyomavirus, lymphocryptovirus, and cytomegalovirus, macaque viruses analogous to HSCT-associated human counterparts BK virus, Epstein-Barr virus, and human cytomegalovirus. Viral replication in recipient macaques resulted in characteristic disease manifestations observed in HSCT patients, such as polyomavirus-associated hemorrhagic cystitis and tubulointerstitial nephritis or lymphocryptovirus-associated post-transplant lymphoproliferative disorder. However, in most cases, the reconstituted immune system, alone or in combination with short-term pharmacological intervention, exerted control over viral replication, suggesting engraftment of functional donor-derived immunity. Indeed, the donor-derived reconstituted immune systems of two long-term engrafted HSCT recipient macaques responded to live attenuated yellow fever 17D vaccine (YFV 17D) indistinguishably from untransplanted controls, mounting 17D-targeted neutralizing antibody responses and clearing YFV 17D within 14 days. Together, these data demonstrate that this macaque model of allogeneic HSCT recapitulates clinical situations of opportunistic viral infections in transplant patients and provides a pre-clinical model to test novel prophylactic and therapeutic modalities. 相似文献
990.
Impact of remnant vital tissue after locoregional treatment and liver transplant in hepatocellular cancer patients,a multicentre cohort study
下载免费PDF全文
![点击此处可从《Transplant international》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Tommaso M. Manzia Samuele Iesari M. Thamara P. R. Perera Mina Komuta Amanda Carvalheiro Tahir Shah Roberta Angelico Claudia Quaranta Daniele Nicolini Roberto Montalti Marina Scarpelli Giampiero Palmieri Antonio Orlacchio Marco Vivarelli Mario Angelico Jan Lerut Giuseppe Tisone 《Transplant international》2018,31(9):988-998
The role of pathological findings after locoregional treatments as predictors of hepatocellular cancer recurrence after liver transplantation has been poorly addressed. The aim of the study was to identify the role of remnant vital tissue (RVT) of the target lesion in predicting hepatocellular cancer recurrence. Two hundred and seventy‐six patients firstly undergoing locoregional treatment and then transplanted between January 2010 and December 2015 in four European Transplant Centres (i.e. Rome Tor Vergata, Birmingham, Brussels and Ancona) were enrolled in the study to investigate the role of pathological response at upfront locoregional treatment. At multivariable Cox regression analysis, RVT ≥2 cm was a strong independent risk factor for post‐LT recurrence (HR = 5.6; P < 0.0001). Five‐year disease‐free survival rates were 60.8%, 80.9% and 95.0% in patients presenting a RVT ≥2 cm vs. 0.1–1.9 vs. no RVT, respectively. When only Milan Criteria‐IN patients were analysed, similar results were reported, with 5‐year disease‐free survival rates of 58.1%, 79.0% and 94.0% in patients presenting a RVT ≥2 cm vs. 0.1–1.9 vs. no RVT, respectively. RVT is an important determinant of tumour recurrence after liver transplantation performed for hepatocellular cancer. Its discriminative power looks to be evident also in a Milan‐IN setting, suggesting to more liberally use locoregional treatments also in these patients. 相似文献