Competition between B-Z and B-L transitions in a single DNA molecule: Computational studies

Under negative torsion, DNA adopts left-handed helical forms, such as Z-DNA and L-DNA. Using the random copolymer model developed for a wormlike chain, we represent a single DNA molecule with structural heterogeneity as a helical chain consisting of monomers which can be characterized by different helical senses and pitches. By Monte Carlo simulation, where we take into account bending and twist fluctuations explicitly, we study sequence dependence of B-Z transitions under torsional stress and tension focusing on the interaction with B-L transitions. We consider core sequences, (GC)(n) repeats or (TG)(n) repeats, which can interconvert between the right-handed B form and the left-handed Z form, imbedded in a random sequence, which can convert to left-handed L form with different (tension dependent) helical pitch. We show that Z-DNA formation from the (GC)(n) sequence is always supported by unwinding torsional stress but Z-DNA formation from the (TG)(n) sequence, which are more costly to convert but numerous, can be strongly influenced by the quenched disorder in the surrounding random sequence.National Research Foundation NRF-2012 R1A1A3013044 NRF-2014R1A1A2055681NRF-2012R1A1A2021736IBS-R023-D1NRF-2015R1A2A2A01005916Chemistr

Measurement, Modeling and Simulation of Power Line Channel for Indoor High-Speed Data Communications

The empirical channel model of power line is obtained through impulse response measurements using the pseudo-noise (PN) correlation method. The BER performance for QPSK is also reported as a result of computer simulation with the proposed channel model. Simulation results show that effective mitigation methods are required to support high speed data communication over power line with the acceptable BER

Angiolipoma of the Posterior Mediastinum with Extension into the Spinal Canal: A Case Report

Angiolipoma is a rare benign soft tissue tumor, an unusual variant of lipoma, consisting of fatty and vascular components and located in the subcutis, usually in the trunk and extremities. We report a case of posterior mediastinal angiolipoma extending into the spinal canal and showing both fat and angiomatous features on CT scan

INVESTIGATION ON EFFECTS OF ENLARGED PIPE RUPTURE SIZE AND AIR PENETRATION TIMING IN REALSCALE EXPERIMENT OF SIPHON BREAKER

To ensure the safety of research reactors, the water level must be maintained above the required height. When a pipe ruptures, the siphon phenomenon causes continuous loss of coolant until the hydraulic head is removed. To protect the reactor core from this kind of accident, a siphon breaker has been suggested as a passive safety device. This study mainly focused on two variables: the size of the pipe rupture and the timing of air entrainment. In this study, the size of the pipe rupture was increased to the guillotine break case. There was a region in which a larger pipe rupture did not need a larger siphon breaker, and the water flow rate was related to the size of the pipe rupture and affected the residual water quantity. The timing of air entrainment was predicted to influence residual water level. However, the residual water level was not affected by the timing of air entrainment. The experimental cases, which showed the characteristic of partical sweep-out mode in the separation of siphon breaking phenomenon [2], showed almost same trend of physical properties.ungraded1111Ysciescopu

Resistin enhances the expansion of regulatory T cells through modulation of dendritic cells

<p>Abstract</p> <p>Background</p> <p>Resistin, a member of adipokine family, is known to be involved in the modulation of immune responses including inflammatory activity. Interestingly, resistin is secreted by adipocytes in mice and rats whereas it is secreted by leukocytes in humans. However, the mechanism behind the effect of resistin on the expansion of regulatory T cells (Tregs) remains poorly understood. Therefore, we examined regulatory effect of resistin on the induction and cellular modification of Tregs.</p> <p>Results</p> <p>Both protein and mRNA expression of <it>FoxP3</it>, a representative marker of Tregs, increased in a dose-dependent manner when peripheral blood mononuclear cells were treated with resistin. At the same time, resistin had no direct effect on the induction of <it>FoxP3 </it>in CD4⁺T cells, suggesting an indirect role through other cells type(s). Since DCs are an important player in the differentiation of T cells, we focused on the role of DCs in the modulation of Tregs by resistin. Resistin suppressed the expression of interferon regulatory factor (IRF)-1 and its target cytokines, IL-6, IL-23p19 and IL-12p40, in DCs. Furthermore, <it>FoxP3 </it>expression is increased in CD4⁺T cells when co-cultured with DCs and concomitantly treated with resistin.</p> <p>Conclusion</p> <p>Our results suggest that resistin induces expansion of functional Tregs only when co-cultured with DCs.</p

Ethanol extract of Poria cocos reduces the production of inflammatory mediators by suppressing the NF-kappaB signaling pathway in lipopolysaccharide-stimulated RAW 264.7 macrophages

Background: Poria cocos Wolf, a medicinal fungus, is widely used in traditional medicines in East Asian countries owing to its various therapeutic potentials. Although several studies have demonstrated the anti-inflammatory activity of this fungus, its underlying mechanisms have not yet been clearly defined.Methods: In the present study, we have demonstrated the anti-inflammatory effects of ethanol extract of P. cocos (EEPC) in lipopolysaccaride (LPS)-stimulated RAW 264.7 macrophages. As inflammatory parameters, the productions of nitric oxide (NO), prostaglandin E2 (PGE2), interleukin (IL)-1β and tumor necrosis factor (TNF)-α were evaluated. We also examined the EEPC&apos;s effect on the nuclear factor-kappaB (NF-κB) signaling pathway.Results: Our results indicated that EEPC exhibits a potent inhibitory effect on NO production and inhibits PGE2 release in LPS-induced macrophages without affecting cell viability. EEPC also significantly attenuated LPS-induced secretion of inflammatory cytokines IL-1β and TNF-α. Additionally, LPS-induced expression of inducible NO synthase (iNOS), cyclooxygenase (COX)-2, IL-1β, and TNF-α was decreased by pre-treatment with EEPC at the transcriptional level. Moreover, EEPC clearly inhibited LPS-induced nuclear translocation of NF-κB p65 subunits, which correlated with EEPC&apos;s inhibitory effects on inhibitor kappaB (IκB) degradation. Moreover, EEPC clearly suppressed the LPS-induced DNA-binding activity of NF-κB, as well as the nuclear translocation of the NF-κB p65, which correlated with EEPC&apos;s inhibitory effects on inhibitor kappaB (IκB) degradation.Conclusions: Taken together, our data indicates that EEPC targets the inflammatory response of macrophages via inhibition of iNOS, COX-2, IL-1β, and TNF-α through inactivation of the NF-κB signaling pathway, supporting the pharmacological basis of P. cocos as a traditional herbal medicine for treatment of inflammation and its associated disorders. © 2014 Jeong et al.; licensee BioMed Central Ltd.1

CT Findings of Atypical Adenomatous Hyperplasia in the Lung

OBJECTIVE: The aim of this study was to analyze the computed tomographic (CT) findings of atypical adenomatous hyperplasia (AAH) in the lung. MATERIALS AND METHODS: The CT findings of AAHs in eight patients were retrospectively reviewed. The CT findings of each AAH lesion were evaluated for multiplicity, location, shape, size and internal density of the lesion, the interface between the normal lung and the lesion, the internal features within the lesion and any change of the lesion on the follow-up CT scans (range: 33 to 540 days; average: 145.3 days). RESULTS: The eight patients consisted of three men and five women (age range: 43-71 years). Six of eight patients were asymptomatic. Four of them (50%) had synchronous malignancies in the lung: adenocarcinoma of the lung (n = 3), and metastatic squamous cell carcinoma from the uterus (n = 1). We could identify and evaluate eleven AAH nodules in seven patients on the CT scans. Three patients had multiple AAHs. Seven of the 11 lesions (64%) were located in the upper lobe. All the AAHs showed a well-defined oval or round shape and pure ground-glass opacity (GGO) without any solid component (size: 3.9x3 mm to 19x17 mm; internal attenuation: -467 to -785 HU). All the AAHs showed no change of their size and internal density on the follow-up CT scans. CONCLUSION: Atypical adenomatous hyperplasia is often associated with malignancy. This tumor is shown on CT as persistent well-defined oval or round nodular GGOs without solid components, and it does not change on the follow-up CT.This study is supported by KISTEP, Ministry of Science and Technology, Korea