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排序方式: 共有454条查询结果,搜索用时 15 毫秒
51.
Ortak T Kerem M Uraloğlu M Unlü RE Inözü E Sensöz O 《Plastic and reconstructive surgery》2006,117(6):2082-3; author reply 2083-5
52.
Uraloğlu M Orbay H Unlü RE Sensöz O 《Plastic and reconstructive surgery》2006,117(4):1353; author reply 1353-1353; author reply 1354
53.
54.
Zepp JA Liu C Qian W Wu L Gulen MF Kang Z Li X 《Journal of immunology (Baltimore, Md. : 1950)》2012,189(1):33-37
The effector T cell subset, Th17, plays a significant role in the pathogenesis of multiple sclerosis and of other autoimmune diseases. The signature cytokine, IL-17, engages the IL-17R and recruits the E3-ligase NF-κB activator 1 (Act1) upon stimulation. In this study, we examined the role of TNFR-associated factor (TRAF)4 in IL-17 signaling and Th17-mediated autoimmune encephalomyelitis. Primary cells from TRAF4-deficient mice displayed markedly enhanced IL-17-activated signaling pathways and induction of chemokine mRNA. Adoptive transfer of MOG35-55 specific wild-type Th17 cells into TRAF4-deficient recipient mice induced an earlier onset of disease. Mechanistically, we found that TRAF4 and TRAF6 used the same TRAF binding sites on Act1, allowing the competition of TRAF4 with TRAF6 for the interaction with Act1. Taken together, the results of this study reveal the necessity of a unique role of TRAF4 in restricting the effects of IL-17 signaling and Th17-mediated disease. 相似文献
55.
Cemalettin Aydin Yasin Ay Halil Basel Servet Kavak Bekir ?nan Hava Bekta? Hasan Ali Gümrük?üo?lu Hasan Ekim Halit Demir 《The Journal of membrane biology》2012,245(12):827-832
The objective of this study was to evaluate the effect of levosimendan (chemical formula C14H12N6O) exposure on oxidant/antioxidant status and trace-element levels in the thoracic aorta of rats. Eighteen male Wistar albino rats were randomly divided into two groups of eight animals each. Group 1 was not exposed to levosimendan and served as a control. Levosimendan (12???g/kg) diluted in 10 ml 0.5?% dextrose was administered intraperitoneally to group 2. Animals of both groups were killed after 3?days, and their thoracic aortae were harvested for determination of changes in tissue oxidant/antioxidant status and trace-element levels. The animals in both groups were killed 72?h after levosimendan exposure, and thoracic aortae were harvested for determination of the lipid peroxidation product MDA and antioxidant GSH levels and the activities of antioxidant enzymes such as SOD, GSH-Px and CAT. It was found that MDA, GSH and CAT enzyme levels increased in thoracic aortae of rats after levosimendan administration. SOD and CA enzyme activities and the level of antioxidant GSH decreased in thoracic aortae of rats after levosimendan treatment. Pb, Cd and Fe levels of thoracic aortae were significantly higher (P?<?0.001) and Mg, Mn, Zn and Cu were significantly lower (P?<?0.001) in the levosimendan group compared to the control group. These results suggest that short-term levosimendan treatment caused an increase in free radical production and a decrease in antioxidant enzyme activity in thoracic aortae of levosimendan-treated rats. It also causes a decrease or increase in many mineral levels of the thoracic aorta, which is an undesirable condition for normal pharmacological function. 相似文献
56.
M.A. Habibzadeh M.R. Ay A.R. Kamali Asl H. Ghadiri H. Zaidi 《Physica medica : PM : an international journal devoted to the applications of physics to medicine and biology : official journal of the Italian Association of Biomedical Physics (AIFB)》2012,28(3):191-199
The operation of the bowtie filter in x-ray CT is correct if the object being scanned is properly centered in the scanner’s field-of-view. Otherwise, the dose delivered to the patient and image noise will deviate from optimal setting. We investigate the effect of miscentering on image noise and surface dose on three commercial CT scanners. Six cylindrical phantoms with different size and material were scanned on each scanner. The phantoms were positioned at 0, 2, 4 and 6 cm below the isocenter of the scanner’s field-of-view. Regression models of surface dose and noise were produced as a function of miscentering magnitude and phantom’s size. 480 patients were assessed using the calculated regression models to estimate the influence of patient miscentering on image noise and patient surface dose in seven imaging centers. For the 64-slice CT scanner, the maximum increase of surface dose using the CTDI-32 phantom was 13.5%, 33.3% and 51.1% for miscenterings of 2, 4 and 6 cm, respectively. The analysis of patients’ scout scans showed miscentering of 2.2 cm in average below the isocenter. An average increase of 23% and 7% was observed for patient dose and image noise, respectively. The maximum variation in patient miscentering derived from the comparison of imaging centers using the same scanner was 1.6 cm. Patient miscentering may substantially increase surface dose and image noise. Therefore, technologists are strongly encouraged to pay greater attention to patient centering. 相似文献
57.
58.
Diphtheria toxin (DT) and its N-terminal fragment A (FA) catalyse the transfer of the ADP-ribose moiety of nicotinamide adenine
dinucleotide (NAD) into a covalent linkage with eukaryotic elongation factor 2 (eEF2). DT-induced cytotoxicity is versatile,
and it includes DNA cleavage and the depolymerisation of actin filaments. The inhibition of the ADP-ribosyltransferase (ADPrT)
activity of FA did not affect the deoxyribonuclease activity of FA or its interaction with actin. The toxin entry rate into
cells (HUVEC) was determined by measuring the ADP-ribosyltransferase activity. DT uptake was nearly 80% after 30 min. The
efficiency was determined as Km = 2.2 nM; Vmax = 0.25 pmol.min−1. The nuclease activity was tested with hyperchromicity experiments, and it was concluded that G-actin has an inhibitory effect
on DT nuclease activity. In thepresence of DT and mutant of diphtheria toxin (CRM197), F-actin depolymerisation was determined
with gel filtration, WB and fluorescence techniques. In the presence of DT and CRM197, 60–65% F-actin depolymerisation was
observed. An in vitro FA-actin interaction and F-actin depolymerisation were reported in our previous paper. The present study thus confirms the
depolymerisation of actin cytoskeleton in vivo. 相似文献
59.
In recent years, information theory has come into the focus of researchers interested in the sensorimotor dynamics of both robots and living beings. One root for these approaches is the idea that living beings are information processing systems and that the optimization of these processes should be an evolutionary advantage. Apart from these more fundamental questions, there is much interest recently in the question how a robot can be equipped with an internal drive for innovation or curiosity that may serve as a drive for an open-ended, self-determined development of the robot. The success of these approaches depends essentially on the choice of a convenient measure for the information. This article studies in some detail the use of the predictive information (PI), also called excess entropy or effective measure complexity, of the sensorimotor process. The PI of a process quantifies the total information of past experience that can be used for predicting future events. However, the application of information theoretic measures in robotics mostly is restricted to the case of a finite, discrete state-action space. This article aims at applying the PI in the dynamical systems approach to robot control. We study linear systems as a first step and derive exact results for the PI together with explicit learning rules for the parameters of the controller. Interestingly, these learning rules are of Hebbian nature and local in the sense that the synaptic update is given by the product of activities available directly at the pertinent synaptic ports. The general findings are exemplified by a number of case studies. In particular, in a two-dimensional system, designed at mimicking embodied systems with latent oscillatory locomotion patterns, it is shown that maximizing the PI means to recognize and amplify the latent modes of the robotic system. This and many other examples show that the learning rules derived from the maximum PI principle are a versatile tool for the self-organization of behavior in complex robotic systems. 相似文献
60.
Demirkan A van Duijn CM Ugocsai P Isaacs A Pramstaller PP Liebisch G Wilson JF Johansson Å Rudan I Aulchenko YS Kirichenko AV Janssens AC Jansen RC Gnewuch C Domingues FS Pattaro C Wild SH Jonasson I Polasek O Zorkoltseva IV Hofman A Karssen LC Struchalin M Floyd J Igl W Biloglav Z Broer L Pfeufer A Pichler I Campbell S Zaboli G Kolcic I Rivadeneira F Huffman J Hastie ND Uitterlinden A Franke L Franklin CS Vitart V;DIAGRAM Consortium Nelson CP Preuss M;CARDIoGRAM Consortium Bis JC O'Donnell CJ 《PLoS genetics》2012,8(2):e1002490
Phospho- and sphingolipids are crucial cellular and intracellular compounds. These lipids are required for active transport, a number of enzymatic processes, membrane formation, and cell signalling. Disruption of their metabolism leads to several diseases, with diverse neurological, psychiatric, and metabolic consequences. A large number of phospholipid and sphingolipid species can be detected and measured in human plasma. We conducted a meta-analysis of five European family-based genome-wide association studies (N = 4034) on plasma levels of 24 sphingomyelins (SPM), 9 ceramides (CER), 57 phosphatidylcholines (PC), 20 lysophosphatidylcholines (LPC), 27 phosphatidylethanolamines (PE), and 16 PE-based plasmalogens (PLPE), as well as their proportions in each major class. This effort yielded 25 genome-wide significant loci for phospholipids (smallest P-value = 9.88×10−204) and 10 loci for sphingolipids (smallest P-value = 3.10×10−57). After a correction for multiple comparisons (P-value<2.2×10−9), we observed four novel loci significantly associated with phospholipids (PAQR9, AGPAT1, PKD2L1, PDXDC1) and two with sphingolipids (PLD2 and APOE) explaining up to 3.1% of the variance. Further analysis of the top findings with respect to within class molar proportions uncovered three additional loci for phospholipids (PNLIPRP2, PCDH20, and ABDH3) suggesting their involvement in either fatty acid elongation/saturation processes or fatty acid specific turnover mechanisms. Among those, 14 loci (KCNH7, AGPAT1, PNLIPRP2, SYT9, FADS1-2-3, DLG2, APOA1, ELOVL2, CDK17, LIPC, PDXDC1, PLD2, LASS4, and APOE) mapped into the glycerophospholipid and 12 loci (ILKAP, ITGA9, AGPAT1, FADS1-2-3, APOA1, PCDH20, LIPC, PDXDC1, SGPP1, APOE, LASS4, and PLD2) to the sphingolipid pathways. In large meta-analyses, associations between FADS1-2-3 and carotid intima media thickness, AGPAT1 and type 2 diabetes, and APOA1 and coronary artery disease were observed. In conclusion, our study identified nine novel phospho- and sphingolipid loci, substantially increasing our knowledge of the genetic basis for these traits. 相似文献