Association of the XRCC1 gene polymorphisms with cancer risk in Turkish breast cancer patients

The X-ray repair cross-complementing group 1 (XRCC1) gene is believed to play an important role in base excision repair and displays genetic polymorphisms. Data on the role of XRCC1 polymorphisms in cancer susceptibility is inconsistent. In the present study, we investigated the effect of two XRCC1 polymorphisms, Arg194Trp and Arg399Gln, on breast cancer risk in a case- control study involving Turkish breast cancer patients and healthy women. Both alleles exhibited a similar distribution among cases and controls leading to lack of any significant association between the XRCC1 polymorphisms and breast cancer risk, either in homozygotes and heterozygotes or combined. The allele frequency of the codon 194 variant was very low in cases and healthy individuals (5.3 and 3.9%, respectively) compared to that of the variant 399Gln allele (39.7 and 37.4%). Our results do not support evidence for a role of the XRCC1 polymorphism in developing breast cancer.     

A dynamical approach to topography estimation in atomic force microscopy based on smooth orthogonal decomposition

Nonlinear Dynamics - Atomic force microscope (AFM) is one of the most versatile and powerful devices capable of producing high-resolution images of nanomaterial. Many researchers are widely...     

An efficient method for synthesis of organophosphorus compounds in aqueous media

A convenient and facile one-pot synthesis of stable phosphorus ylides and 1,4-diionic organophosphorus compounds is reported by the reaction of triphenylphosphine,dialkylacetylenedicarboxylates and N-H,C-H or S-H acids in the presence of polyethyleneglycol (PEG),β-cyclodextrin(β-CD),glycerine(Gly) or ethyleneglycol(EG) in water.This methodology is of interest due to the use of water as a solvent,thus minimizing the cost operational hazards,and environmental pollution.     

Vitamin D receptor gene polymorphisms in breast cancer

Breast cancer is the leading cause of cancer death among women around the world and its incidence is annually increasing. The vitamin D receptor (VDR) gene is a member of the nuclear receptor superfamily, which is expressed in breast tissue and known to modulate the rate of cell proliferation. Association between the VDR gene polymorphisms and cancer development has been suggested by several studies. However, the relationship between VDR polymorphisms and breast cancer is controversial and has not been confirmed by all studies. The purpose of this study was to investigate the genotype frequencies and association of the VDR Bsm I and Taq I polymorphisms with breast cancer in Turkish patients. In this study, 78 patients with breast cancer and 27 healthy individuals were enrolled. The prevalence of the VDR Taq I and Bsm I alleles and the genotype frequencies in patients with breast cancer was similar to that in the normal population. Our data indicate that no significant differences exist between the patients and control subjects.     

Preparation and Characterization of Ni‐Modified Graphene Oxide Complex as an Efficient Catalyst for the Synthesis of Sulfides via Reaction of Arylhalides with S8 or Thiourea

In this work, complex of Ni‐modified graphene oxide was prepared and characterized using FT‐IR spectroscopy, SEM, XRD, TGA and ICP‐OES techniques. This compound used as an efficient and recoverable catalyst for the C–S coupling reaction using sulfur‐transfer reagents (S₈ or thiourea). The catalyst was easily separated using a simple filtration and reusable without significant loss of their catalytic efficiency.     

A Newton–Krylov finite volume algorithm for the power-law non-Newtonian fluid flow using pseudo-compressibility technique

An implicit Newton–Krylov finite volume algorithm has been developed for efficient steady-state computation of the power-law non-Newtonian fluid flows. The pseudo-compressibility technique is used for the coupling of continuity and momentum equations. The spatial discretization is central (second-order) for both convective and diffusive terms and the accuracy of the solution is verified. The nine block diagonal Jacobian matrix (needed for implicit formulation) is computed directly through the flux differentiation. Five-diagonal and three-diagonal block matrices (the simplified versions of the main Jacobian matrix) are used with the ILU(0 & 1) and the Thomas linear solvers for preconditioning, respectively. The performance of the Newton-GMRES solver is examined in detail for different preconditioning strategies. The effects of the power-law behavior index and Re number on the convergence rate are also studied. The performance of the Newton-BiCGSTAB and the Newton-GMRES solvers are compared with each other. The results show, the ILU(1)/Newton-GMRES is the most efficient combination that is robust even in high Reynolds number shear-thinning fluid flow cases.     

1,4‐Diazabicyclo[2.2.2]octane‐Catalyzed One‐Pot Synthesis of Pyrazolo[1,2‐a][1,2,4]triazole‐1,3‐diones under Ultrasound Acceleration

1,4‐Diazabicyclo[2.2.2]octane has been explored as an efficient catalyst to effect the three‐component condensation reactions between malononitrile, 4‐arylurazoles, and aromatic aldehydes in ethanol under ultrasound irradiation conditions. The reactions proceeded very rapidly under mild conditions to furnish the corresponding pyrazolo[1,2‐a][1,2,4]triazole‐1,3‐dione derivatives in excellent yields.     

Wet 2,4,6-trichloro-1,3,5-triazine(TCT)as an efficient catalyst for the synthesis of 2,4,6-triarylpyridines under solvent-free conditions

<正>An efficient one-pot synthesis of 2,4,6-triarylpyridines has been described.This involves the three-component reaction of aldehydes,ketones and ammonium acetate in the presence of a catalytic amount of wet 2,4,6-trichloro-1,3,5-triazine(TCT) under solvent-free condition at 130℃.     

A high-order accurate unstructured finite volume Newton–Krylov algorithm for inviscid compressible flows

A fast implicit Newton–Krylov finite volume algorithm has been developed for high-order unstructured steady-state computation of inviscid compressible flows. The matrix-free generalized minimal residual (GMRES) algorithm is used for solving the linear system arising from implicit discretization of the governing equations, avoiding expensive and complex explicit computation of the high-order Jacobian matrix. The solution process has been divided into two phases: start-up and Newton iterations. In the start-up phase an approximate solution with the general characteristics of the steady-state flow is computed by using a defect correction procedure. At the end of the start-up phase, the linearization of the flow field is accurate enough for steady-state solution, and a quasi-Newton method is used, with an infinite time step and very rapid convergence. A proper limiter implementation for efficient convergence of the high-order discretization is discussed and a new formula for limiting the high-order terms of the reconstruction polynomial is introduced. The accuracy, fast convergence and robustness of the proposed high-order unstructured Newton–Krylov solver for different speed regimes is demonstrated for the second, third and fourth-order discretization. The possibility of reducing computational cost required for a given level of accuracy by using high-order discretization is examined.     

Comparison of the shape parameters of DNA-cationic lipid complexes and model polyelectrolyte-lipid complexes

In this study, we used a rheological method to study the shape of DNA-cationic lipid complexes and model polyelectrolyte-lipid complexes. We introduced two kinds of anionic polyelectrolytes, sodium polygalacturonate (PGU) and sodium dextran sulfate (DSS), of varying size, as models for DNA. The prepared complexes were incubated under laminar flow conditions. The results show the same quantitative relation between the shape parameter of lipoplexes and the length of anionic polyelectrolytes, including DNA. The rheological behavior of PGU and DSS were similar to that of DNA.