全文获取类型
收费全文 | 408篇 |
免费 | 38篇 |
国内免费 | 1篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 18篇 |
妇产科学 | 8篇 |
基础医学 | 92篇 |
口腔科学 | 1篇 |
临床医学 | 39篇 |
内科学 | 112篇 |
神经病学 | 27篇 |
特种医学 | 7篇 |
外科学 | 40篇 |
综合类 | 4篇 |
一般理论 | 1篇 |
预防医学 | 26篇 |
眼科学 | 8篇 |
药学 | 24篇 |
中国医学 | 1篇 |
肿瘤学 | 37篇 |
出版年
2023年 | 10篇 |
2022年 | 4篇 |
2021年 | 29篇 |
2020年 | 11篇 |
2019年 | 16篇 |
2018年 | 17篇 |
2017年 | 21篇 |
2016年 | 17篇 |
2015年 | 18篇 |
2014年 | 26篇 |
2013年 | 27篇 |
2012年 | 40篇 |
2011年 | 36篇 |
2010年 | 22篇 |
2009年 | 16篇 |
2008年 | 29篇 |
2007年 | 28篇 |
2006年 | 29篇 |
2005年 | 14篇 |
2004年 | 16篇 |
2003年 | 7篇 |
2002年 | 7篇 |
2001年 | 1篇 |
1998年 | 2篇 |
1993年 | 2篇 |
1977年 | 1篇 |
1971年 | 1篇 |
排序方式: 共有447条查询结果,搜索用时 15 毫秒
1.
Stacy Loeb Shomik Sengupta Mohit Butaney Joseph N. Macaluso Stefan W. Czarniecki Rebecca Robbins R. Scott Braithwaite Lingshan Gao Nataliya Byrne Dawn Walter Aisha Langford 《European urology》2019,75(4):564-567
YouTube is a social media platform with more than 1 billion users and >600 000 videos about prostate cancer. Two small studies examined the quality of prostate cancer videos on YouTube, but did not use validated instruments, examine user interactions, or characterize the spread of misinformation. We performed the largest, most comprehensive examination of prostate cancer information on YouTube to date, including the first 150 videos on screening and treatment. We used the validated DISCERN quality criteria for consumer health information and the Patient Education Materials Assessment Tool, and compared results for user engagement. The videos in our sample had up to 1.3 million views (average 45 223) and the overall quality of information was moderate. More videos described benefits (75%) than harms (53%), and only 50% promoted shared decision-making as recommended in current guidelines. Only 54% of the videos defined medical terms and few provided summaries or references. There was a significant negative correlation between scientific quality and viewer engagement (views/month p = 0.004; thumbs up/views p = 0.015). The comments section underneath some videos contained advertising and peer-to-peer medical advice. A total of 115 videos (77%) contained potentially misinformative and/or biased content within the video or comments section, with a total reach of >6 million viewers.
Patient summary
Many popular YouTube videos about prostate cancer contained biased or poor-quality information. A greater number of views and thumbs up on YouTube does not mean that the information is trustworthy. 相似文献2.
3.
Nathalie T. Joncker Nataliya Shifrin Frédéric Delebecque David H. Raulet 《The Journal of experimental medicine》2010,207(10):2065-2072
Some mature natural killer (NK) cells cannot be inhibited by major histocompatibility complex (MHC) I molecules, either because they lack corresponding inhibitory receptors or because the host lacks the corresponding MHC I ligands for the receptors. Such NK cells nevertheless remain self-tolerant and exhibit a generalized hyporesponsiveness to stimulation through activating receptors. To address whether NK cell responsiveness is set only during the NK cell differentiation process, we transferred mature NK cells from wild-type (WT) to MHC I–deficient hosts or vice versa. Remarkably, mature responsive NK cells from WT mice became hyporesponsive after transfer to MHC I–deficient mice, whereas mature hyporesponsive NK cells from MHC I–deficient mice became responsive after transfer to WT mice. Altered responsiveness was evident among mature NK cells that had not divided in the recipient animals, indicating that the cells were mature before transfer and that alterations in activity did not require cell division. Furthermore, the percentages of NK cells expressing KLRG1, CD11b, CD27, and Ly49 receptors specific for H-2b were not markedly altered after transfer. Thus, the functional activity of mature NK cells can be reset when the cells are exposed to a changed MHC environment. These findings have important implications for how NK cell functions may be curtailed or enhanced in the context of disease.An important role of NK cells is to eliminate cells that extinguish or diminish expression of self-MHC class I molecules, which commonly occurs as a result of viral infection or cellular transformation (Herberman et al., 1975; Kiessling et al., 1975; Biron et al., 1999; Diefenbach and Raulet, 2002). This capacity arises because NK cells express stimulatory and inhibitory receptors that engage ligands on normal cells. The majority of inhibitory receptors belong to the KIR (in human), Ly49 (in mouse), and CD94/NKG2A (both in human and mouse) families and are specific for MHC I molecules (Raulet et al., 1997; Moretta et al., 2001; Lanier, 2005). When an NK cell encounters a normal cell, engagement of the inhibitory receptors conveys signals that counteract stimulatory signaling. Lysis occurs when inhibition is lost because the target cell lacks one or more self-MHC molecules or when target cells express high levels of stimulatory ligands that override inhibition (Raulet and Vance, 2006).NK cells vary in the number and specificity of MHC-specific inhibitory receptors that they express (Raulet et al., 1997). Recent studies demonstrate that NK cells vary in basal responsiveness to stimulatory receptor engagement depending on the number of expressed inhibitory receptors specific for self-MHC molecules (Yu et al., 2007; Brodin et al., 2009; Joncker et al., 2009). Cells with several self-MHC–specific receptors exhibit the greatest basal responsiveness and thus mediate the greatest activity against target cells that lose MHC. Cells with no self-MHC–specific receptors are the most hyporesponsive, to the extent that they fail to attack otherwise normal cells lacking MHC molecules. These data suggest that the responsiveness set point of individual NK cells is tuned depending on the balance of inhibitory and stimulatory ligands that each NK cell encounters on neighboring cells in the normal environment (Joncker and Raulet, 2008).An important unanswered question is whether the basal responsiveness of NK cells is set only once during NK cell development or, alternatively, can be readjusted when the fully mature NK cell is exposed to a changing MHC environment. Readjustments of NK cell responsiveness, if they occur, may account for instances under which NK cells fail to eliminate tumors or pathogen-infected cells and will be important to address when testing therapies designed to augment or suppress NK cell activity in the context of disease. 相似文献
4.
Federico Pappalardo Martina Crivellari Ambra L. Di Prima Nataliya Agracheva Malgorzata Celinska-Spodar Rosalba Lembo Daiana Taddeo Giovanni Landoni Alberto Zangrillo 《Intensive care medicine》2016,42(11):1706-1714
Purpose
To determine whether protein C zymogen (protein C concentrates or human protein C) improves clinically relevant outcomes in adult patients with severe sepsis and septic shock.Methods
This is a randomized, double-blind, placebo-controlled, parallel-group trial that from September 2012 to June 2014 enrolled adult patients with severe sepsis or septic shock and high risk of death and of bleeding (e.g., APACHE II greater than 25, extracorporeal membrane oxygenation or disseminated intravascular coagulopathy). All patients completed their follow-up 90 days after randomization and data were analyzed according to the intention-to-treat principle. Follow-up was performed at 30 and 90 days after randomization. The primary endpoint was a composite outcome of prolonged intensive care unit (ICU) stay and/or 30-day mortality. Secondary endpoints included mortality.Results
The study was stopped early in a situation of futility for the composite outcome of prolonged ICU stay and/or 30-day mortality that was 79 % (15 patients) in the protein C zymogen group and 67 % (12 patients) in the placebo group (p = 0.40) and for a concomitant safety issue: ICU mortality was 79 % (15 patients) in the protein C zymogen group vs 39 % (7 patients) in the placebo group (p = 0.020), and 30-day mortality was 68 vs 39 % (p = 0.072).Conclusion
Protein C zymogen did not improve clinically relevant outcomes in severe sepsis and septic shock adult patients. Given its high cost and the potential increase in mortality, the use of this drug in adult patients should be discouraged.5.
6.
Nataliya V. Dolgushina Anastasiia G. Syrkasheva Nataliya P. Makarova Eugenia V. Kovalskaya Elena A. Kalinina Gennady T. Sukhikh 《Gynecological endocrinology》2015,31(10):61-64
AbstractPurpose: To evaluate the aneuploidy rates of 13, 18, and 21 and the X and Y chromosomes in embryos from patients with morphologically normal oocytes and different oocyte dysmorphisms.Methods: This prospective cohort study included 84 patients treated with in vitro fertilization (IVF) at a single academic center. The patients were divided into the following three groups: group 1 – women with cytoplasmic dysmorphisms (n?=?28), group 2 – women with extracytoplasmic dysmorphisms (n?=?28), and group 3 – women with morphologically normal oocytes (n?=?28). One blastomere from each embryo was analyzed for aneuploidies of chromosomes 13, 18, 21, X, and Y.Results: The highest prevalence of aneuploid embryos was observed in the group 1 (68.4%) followed by the group 2 (38.9%) and the group 3 (31.3%) (р?<?0.0001). The adjusted OR for receiving an aneuploid embryo in the case of cytoplasmic dysmorphism was 3.6 (95% CI?=?1.8; 7.2), in the case of extracytoplasmic dysmorphisms – 1.3 (95% CI?=?0.7; 2.1).Conclusions: Women with morphological oocyte abnormalities are at risk for developing aneuploid embryos during IVF cycles. We recommend that woman with cytoplasmic oocyte dysmorphisms receive additional genetic counseling to define the indications for the genetic screening of embryos. 相似文献
7.
Andreas Tzschach Ute Grasshoff Stefanie Beck-Woedl Claudia Dufke Claudia Bauer Martin Kehrer Christina Evers Ute Moog Barbara Oehl-Jaschkowitz Nataliya Di Donato Robert Maiwald Christine Jung Alma Kuechler Solveig Schulz Peter Meinecke Stephanie Spranger Jürgen Kohlhase J?rg Seidel Silke Reif Manuela Rieger Angelika Riess Marc Sturm Julia Bickmann Christopher Schroeder Andreas Dufke Olaf Riess Peter Bauer 《European journal of human genetics : EJHG》2015,23(11):1513-1518
X-linked intellectual disability (XLID) is a genetically heterogeneous disorder with more than 100 genes known to date. Most genes are responsible for a small proportion of patients only, which has hitherto hampered the systematic screening of large patient cohorts. We performed targeted enrichment and next-generation sequencing of 107 XLID genes in a cohort of 150 male patients. Hundred patients had sporadic intellectual disability, and 50 patients had a family history suggestive of XLID. We also analysed a sporadic female patient with severe ID and epilepsy because she had strongly skewed X-inactivation. Target enrichment and high parallel sequencing allowed a diagnostic coverage of >10 reads for ~96% of all coding bases of the XLID genes at a mean coverage of 124 reads. We found 18 pathogenic variants in 13 XLID genes (AP1S2, ATRX, CUL4B, DLG3, IQSEC2, KDM5C, MED12, OPHN1, SLC9A6, SMC1A, UBE2A, UPF3B and ZDHHC9) among the 150 male patients. Thirteen pathogenic variants were present in the group of 50 familial patients (26%), and 5 pathogenic variants among the 100 sporadic patients (5%). Systematic gene dosage analysis for low coverage exons detected one pathogenic hemizygous deletion. An IQSEC2 nonsense variant was detected in the female ID patient, providing further evidence for a role of this gene in encephalopathy in females. Skewed X-inactivation was more frequently observed in mothers with pathogenic variants compared with those without known X-linked defects. The mutation rate in the cohort of sporadic patients corroborates previous estimates of 5–10% for X-chromosomal defects in male ID patients. 相似文献
8.
9.
10.