Effect of Helicobacter pylori infection on deep vein thrombosis seen in patients with Behçet's disease

Objective: To investigate the role of homocysteine metabolism due to Helicobacter pylori infection on the development of deep vein thrombosis (DVT) in patients with Behcet's disease (BD). Design: Prospective clinical study. Setting: Teaching hospital. Subject: Fifty-five patients with BD divided into groups, with DVT and without DVT, 19 healthy individuals and 18 patients with coronary artery disease (CAD) were enrolled into the study. Interventions: Plasma homocysteine and Hp seropositivity were determined. Results: There was significant Hp positivity in all groups (p>0.05). Homocysteine levels were not significantly different for each group except patients with CAD (p>0.05). Conclusion: There was no difference for frequency of Hp infection in all groups. We conclude that Hp does not influence DVT seen in BD via homocysteine metabolism, but the methinnin-loading test would be appropriate for enlighting patients whose fasting plasma homocysteine levels are found to be normal. East African Medical Journal Vol. 83(1) 2006: 49-5

Second and third-order nonlinear optical behavior of natural pigment: chlorophyll and crocin

To provide an insight into the microscopic second and third-order nonlinear optical (NLO) behavior of chlorophyll a and crocin, we have computed the electric dipole moments (μ), dispersion-free first hyperpolarizabilities (β), frequency-dependent first and second (γ) hyperpolarizabilities at 1064 nm wavelength area using time-dependent Hartree-Fock (TDHF) method. According to ab-initio calculation results, the examined compounds exhibit first and second hyperpolarizabilities with non-zero values, implying second and third-order NLO phenomena

Computational studies on linear, second and third-order nonlinear optical properties of novel styrylquinolinium dyes

The electric dipole moments (μ), static dipole polarizabilities (α) and first hyperpolarizabilities (β) of styrylquinolinium dyes, D8 and D21, have been computed by density functional theory (DFT). The one-photon absorption (OPA) characterizations have been investigated using UV–vis spectroscopy and further interpreted using computational chemistry. The time-dependent Hartree–Fock (TDHF) method has been used to describe the dynamic dipole polarizabilities, dynamic second-order and also static and dynamic third-order nonlinear optical (NLO) properties. D8–D21 have rather high β and second hyperpolarizabilities (γ). The highest occupied molecular orbitals (HOMO), the lowest unoccupied molecular orbitals (LUMO) and the HOMO–LUMO band gaps for D8–D21 have been evaluated by DFT

A parallel boundary element formulation for tracking multiple particle trajectories in Stoke's flow for microfluidic applications

A new formulation for tracking multiple particles in slow viscous flow for microfluidic applications is presented. The method employs the manipulation of the boundary element matrices so that finally a system of equations is obtained relating the rigid body velocities of the particle to the forces applied on the particle. The formulation is specially designed for particle trajectory tracking and involves successive matrix multiplications for which SMP (Symmetric multiprocessing) parallelisation is applied. It is observed that present formulation offers an efficient numerical model to be used for particle tracking and can easily be extended for multiphysics simulations in which several physics involved. Copyright © 2015 Tech Science Press

Mating type idiomorphs of Pyrenophora teres in Turkey

Pyrenophora teres f. maculata (Ptm) and Pyrenophora teres f. teres (Ptt) causes spot form and net form of net blotch diseases of barley, respectively. Although both forms of P. teres are morphologically similar, their symptoms and genetic background differ. In this study, 175 single spore (109 Ptm and 66 Ptt) isolates obtained from different regions of Turkey were evaluated for their mating type distribution and prevalence. Fungal isolates of both forms were verified using species-speci.c polymerase chain reaction (PCR) primers. For mating type determination studies, duplex PCR was performed using MAT-specific single nucleotide polymorphism primers. Sixty and 49 of 109 Ptm isolates were found as MAT1-1 and MAT1-2 types, respectively and 43 and 23 of 66 Ptt isolates were found as MAT1-1 and MAT1-2 types, respectively. These results show the possibility of sexual reproduction among the Ptm isolates in Turkey and Ptt population of Central Anatolia, Turkey. However, the overall pattern of Ptt isolates did not support the sexual reproduction hypothesis in Turkey. Sexual reproduction in the life cycle of P. teres is important since it could lead to genetic and pathogenic variation. As a result of new sexual combinations more virulent pathotypes of P. teres may occur

Boron Stress Activates the General Amino Acid Control Mechanism and Inhibits Protein Synthesis

Boron is an essential micronutrient for plants, and it is beneficial for animals. However, at high concentrations boron is toxic to cells although the mechanism of this toxicity is not known. Atr1 has recently been identified as a boron efflux pump whose expression is upregulated in response to boron treatment. Here, we found that the expression of ATR1 is associated with expression of genes involved in amino acid biosynthesis. These mechanisms are strictly controlled by the transcription factor Gcn4 in response to boron treatment. Further analyses have shown that boron impaired protein synthesis by promoting phosphorylation of eIF2α in a Gcn2 kinase dependent manner. The uncharged tRNA binding domain (HisRS) of Gcn2 is necessary for the phosphorylation of eIF2α in the presence of boron. We postulate that boron exerts its toxic effect through activation of the general amino acid control system and inhibition of protein synthesis. Since the general amino acid control pathway is conserved among eukaryotes, this mechanism of boron toxicity may be of general importance

Multi-resampling Doppler compensation in cooperative underwater OFDM systems

We consider a multi-carrier cooperative underwater acoustic communication (UWAC) system and investigate the Doppler scaling problem arising due to the motion of different nodes. Specifically, we assume an orthogonal frequency division multiplexing (OFDM) system with amplify and forward (AF) relaying. Our channel model is built on large-scale path loss along with the short-term frequency-selective fading. For Doppler scaling compensation, we use multi-resampling (MR) receiver designs both at the relay and destination nodes. We present an extensive Monte Carlo simulation study to evaluate the error rate performance of the proposed UWAC system. In simulations, we use the publicly available VirTEX software in conjunction with the ray-tracing based BELLHOP software to precisely reflect the characteristics of an underwater geographical location and the movement of the nodes. © 2013 IEEE