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Efficient cell separation techniques are required for the isolation of various cellular populations in fundamental research. In the present study, five types of magnetic nanoparticles (MNPs) have been designed to isolate CD4+ T cells from peripheral blood mononuclear cells. MNPs were synthesized by a modified solvothermal method and subsequently coated by a silica shell through the sol-gel process. Then, the anti-CD4 antibody was conjugated on the surface of different groups of MNPs, which were functionalized with various cross-linkers (including the carboxylic and aldehyde groups) and proteins (such as protein A and streptavidin). The performance of prepared MNPs for the separation of CD4+ lymphocytes was investigated by optical microscopy and flow-cytometry. This study revealed that the cell isolation rates by different functionalized groups, including aldehyde, carboxyl, CHO-protein A, COOH-protein A, and streptavidin conjugated with nanoparticles, were 32 ± 3, 32 ± 1, 80 ± 4, 70 ± 1, and 71 ± 2%, respectively. Based on such data, the CHO-protein A-functionalized MNPs have been considered a practical choice to separate CD4+ T cells with over 92 ± 3% purity. MNPs obtained in the study provide an adequate tool for the cell isolation method and further present the dramatic potential to be applied to several fields of biomedical purpose. [ABSTRACT FROM AUTHOR]

Nonalcoholic fatty liver disease (NAFLD) is a chronic disorder, which is mainly considered a result of high-fat diet in humans. The clinical spectrum of NAFLD ranges from simple steatosis to nonalcoholic steatohepatitis (NASH) with irreversible complications. Therefore, early treatments, especially with medicinal plants can be considered as an important strategy in NAFLD treatment. This study aimed at investigating the effect of HESA-A (a herbal-marine supplement) on treatment of fatty liver in rats by evaluation of SREBP-1c and NF-kβ genes expression and biochemical analyses. In an experimental study, 28 male Wistar rats (weighing 180 ± 20 g), were divided to two groups and treated with a standard diet (n = 7) and a high-fat diet (HFD) (n = 21) for eight weeks. In order to confirm the NAFLD, the control group and seven rats of the HFD group were killed and biochemical parameters and histopathological changes were analyzed. The rest of the rats were divided to two groups and fed either atorvastatin (30 mg/kg/day) or HESA-A (500 mg/kg/day) for 30 days. Finally, serum biomarkers of liver damage, serum lipid profiles and gene expression of NF-kβ and SREBP-1c were investigated. Semi-quantitative Real Time-Polymerase Chain Reaction (RT-PCR) analyses showed that the expression of SREBP-1c and NF-kβ increased in NAFLD rat model compared to the control group. The expression level of SREBP-1c and NF-kβ genes showed a significant decrease in HESA-A and atorvastatin-treated groups in comparison to the control group. Biochemical analyses also confirmed these results. These findings showed that HESA-A could be used as an effective alternative in treatment of NAFLD with low side effects in comparison with atorvastatin as current medication. [ABSTRACT FROM AUTHOR]

Abnormal grain growth (AGG) phenomenon was observed during cryogenic friction stir processing (FSP) of a severely deformed 1050-aluminum. An ultrahigh cooling rate and a lower peak temperature ahead of the rotating tool along with the preliminarily stored strain within the base metal resulted in the AGG. This event was pronounced not only ahead of the FSP tool, but also in heat affected zone (HAZ). The abnormally grown grains were strain-free and they proceeded to grow beyond the high-angle grain boundaries evolved in the base metal. Also, the incident of AGG was simultaneous with the development of Cube and Goss texture components. The combined effects associated with the development of a dominant shear texture and the existence of strain-free grains in the base metal was found to be linked to the AGG. The base metal encompassed mainly deformed grains with the orientation close to the shear texture component B / B ¯. However, other orientations such as θ-fiber texture were evident too. The observation of abnormally grown grains with orientations different from the dominant shear texture suggested the activation of texture-induced AGG. On the other hand, strain-induced grain boundary migration would be responsible for the AGG of a number of strain-free grains with orientations close to the dominant shear texture. • Abnormal grain growth occurs around stir zone during cryogenic FSP of severely deformed aluminum. • Strong shear texture and remaining strain-free grains result in abnormal grain growth. • Abnormally grown grains either belong to shear textured volume or other orientations. • The Goss texture component develops as abnormal grain growth takes place. • Shear and deformation texture components become weaker as a result of recrystallization and abnormal grain growth. [ABSTRACT FROM AUTHOR]

Abstract Annealed 1050-aluminum sheets were severely deformed at the strain magnitude of 2.32 through constrained groove pressing (CGP) process. Texture variations and mechanical properties were investigated during CGP and subsequent friction stir processing (FSP) with different volume fractions of SiC nanoparticles. The results revealed that the predominant texture component in the annealed aluminum was { 001 } 〈 100 〉 cube texture. After CGP, deformed and shear texture components developed while the cube texture was partially remained. In the specimen undergone FSP without nanoparticles, { 001 } 〈 110 〉 rotated cube and nearly { 001 } 〈 110 〉 shear texture component C were mainly pronounced, which was indicative of shear deformation of material in the stir zone. Orientation distribution function analysis from the stir zone demonstrated variations in the texture development with the incorporation of SiC nanoparticles. An increase in the fraction of nanoparticles changed the grain orientation in such a way that the { 001 } 〈 110 〉 shear texture component C gradually developed from the rotated cube texture. However, the overall texture intensity became weaker by increasing the fraction of SiC nanoparticles due to the activation of particle stimulated nucleation mechanism forming randomly oriented grains. The incorporation of SiC nanoparticles in the stir zone also enhanced the yield strength, Young's modulus, and hardness of the stir zone without considerable reduction in the elongation. In such situation, Orowan strengthening was suggested as a dominant mechanism involved. [ABSTRACT FROM AUTHOR]

The texture, microstructure, and mechanical properties of severely deformed aluminum subjected to friction stir processing (FSP) with SiC nanoparticles under ambient and cryogenic temperatures are comprehensively investigated. Even one pass of FSP in the ambient temperature results in the formation of quite large grain structure with random texture in the heat affected zone (HAZ). It suggests the occurrence of static recrystallization and subsequent grain growth because of the appreciable strain stored within the base metal. One FSP pass under condition of cryogenic temperature causes to the development of bimodal grain size distribution in HAZ, including the elongated grains with interior subgrains and very large grains as a result of texture-induced abnormal grain growth. Large grains with random texture are formed throughout HAZ during further FSP passes. In the stir zone where SiC nanoparticles are dispersed during FSP in the ambient temperature, fine grain structure with the shear texture components of C and A 1 ∗ is obtained through the geometrically dynamic recrystallization mechanism. When FSP is performed in the cryogenic temperature, the grain size of stir zone is decreased because of the increased cooling rate. Although the shear texture components developed in the stir zone are the same at both mentioned processing conditions, the texture strength is less in the case of cryogenic temperature, suggesting the contribution of additional grain formation mechanism, namely discontinuous dynamic recrystallization. This mechanism gives rise to the formation of randomly oriented grains. The nano-indentation test results confirm that FSP under cryogenic temperature improves the mechanical properties not only in the stir zone, but also in HAZ. [ABSTRACT FROM AUTHOR]

The rubber friction coefficient, and the contact area during stationary sliding is calculated, for the contact of a polished rubber block and a concrete surface, when both surfaces are rough. The calculation is based on an extended version of Persson's contact mechanics theory. Compared to only the substrate being rough, when both of the surfaces are rough but their cross correlation is zero, the friction coefficient is larger. Introducing a positive correlation decreases the friction coefficient, while introducing a negative correlation increases the friction coefficient. To support these theoretical arguments, some experiments have been performed. We have produced roughness on the rubber surface, using abrasive paper, and measured the surface topographies for the concrete and the polished rubber surfaces. The auto spectral density functions for the both surfaces have been calculated, and the rubber viscoelastic modulus mastercurve has been obtained. We have measured the rubber friction at different sliding velocities, when the rubber surfaces are rough and smooth, and compared it to the theoretical results. It is seen that when the rubber surface is rough, the rubber friction coefficient is larger compared to the case the rubber surface is smooth. The theoretical results are in good agreement with experimental observation. [ABSTRACT FROM AUTHOR]

In this paper, the mechanical properties of graphene oxide are obtained using the molecular dynamics analysis, including the ultimate stress, Young modulus, shear modulus and elastic constants, and the results are compared with those of pristine graphene. It is observed that the increase of oxide agents (–O) and (–OH) leads to the increase of C–C bond length at each hexagonal lattice and as a result, alter the mechanical properties of the graphene sheet. It is shown that the elasticity modulus and ultimate tensile strength of graphene oxides (–O) and (–OH) decrease significantly causing the failure behavior of graphene sheet changes from the brittle to ductile. The results of shear loading tests illustrate that the increase of oxide agents (–O/–OH) results in the decrease of ultimate shear stress and shear module of the graphene sheet. It is shown that the increase of oxide agents in the graphene sheet leads to decrease of the elastic constants, in which the reduction of elastic properties in the armchair direction is more significant than the zigzag direction. Moreover, the graphene sheet with oxide agents (–O) and (–O/–OH) presents an anisotropic behavior. [ABSTRACT FROM AUTHOR]

In this research, 1050 aluminum sheets in the conditions of annealed and severely deformed by 2 passes of constrained groove pressing (CGP) process were used. Two passes of friction stir processing (FSP) were applied on the specimens. Also, another CGPed specimen was processed by 2 passes of FSP using SiC nanoparticles. The samples were then heat treated to study thermal stability of base metal, heat affected zone (HAZ), thermo-mechanically affected zone (TMAZ), and stir zone (SZ). Microstructure examinations revealed that the annealed base metal was relatively stable upon heating even up to 400 °C and a little grain growth was evident. On the other hand, the CGPed base metal was fairly stable just up to 200 °C. It was also observed that HAZ and TMAZ of annealed specimen exhibited some grain growth while for CGPed sample, these regions experienced recrystallization and subsequent grain growth during heat treatment. It was found that the SZ of annealed and CGPed specimens remained fine after heat treatment even up to 400 °C and slight grain growth occurred. Microstructural assessments revealed that using SiC nanoparticles during FSP had a potential to form finer grain structure at SZ compared with that in specimen FSPed without any particle. Also, it was found that SiC nanoparticles could hinder grain growth during heat treatment provided that a suitable distribution nanoparticles was formed. [ABSTRACT FROM AUTHOR]

In-situ aluminum matrix composites were fabricated by 1–3 passes of friction stir process (FSP) using iron (Fe) particles with initial size of 10 µm. Although the initial reinforcing particles were relatively large in size and also agglomerated particles were formed in the obtained composites, all of the processed specimens fractured from the base metal during transverse tensile test. Longitudinal tensile tests revealed that the ultimate tensile strength (UTS) of the composites was up to 43% higher than that of the base metal; however, the strain to fracture of the composites reached to about 0.2. Al–Fe intermetallic compounds (IMCs) formed at the interface of the aluminum matrix and Fe particles were responsible for the suitable metallurgical bond between the reinforcing particles and aluminum matrix along with the superior mechanical properties of the processed composites. Microstructure examinations showed that the grain structure at the stir zone was somewhat refined after FSP without any Fe particles compared with the base metal. However, in the case of the composites reinforced by Fe particles, the grain refinement was more obvious at some areas of the stir zone with respect to the FSPed samples without Fe particles. This observation was attributed to the presence of sub-micron Fe particles and/or IMCs and consequently the pinning effect of these particles on the grain boundary migration during grain growth. These areas exhibited superior microhardness values compared with other regions. The enhancement of the FSP pass numbers led to improvement in the distribution of reinforcing particles along with increasing the thickness of IMCs at the interface. Therefore, the UTS of the composites increased with raising the number of FSP passes. [ABSTRACT FROM AUTHOR]

Fe x CoCrAlNi medium and high entropy layers were fabricated on a carbon steel using multilayer TIG cladding. The Fe content of the deposited layers decreased by moving away from the substrate due to the dilution effect. Fe x CoCrAlNi (with x > 1) medium entropy alloys (MEAs) with a major Fe-rich BCC and minor Fe–Al–Ni-rich FCC phases developed in the inner parts of the fabricated layers. No intermetallic compounds appeared in MEAs. Microstructural assessments revealed that a FeCoCrAlNi high entropy alloy (HEA) containing Al–Ni-rich BCC and Fe–Cr-rich FCC crystal structures was achieved in the upper part of the deposited layers. It was found that Fe–Cr and Al–Ni pairs had contradictory effects on stabilizing crystal structure in MEAs and HEA. The Al–Ni pair was FCC-phase stabilizer in MEA while it was responsible for the formation of BCC phase in HEA. The microhardness of the deposited layers increased successively to reach 430 HV in the HEA due to the solid solution strengthening and formation of BCC phase with high-entropy characteristics. • A multi-layered FeCoCrAlNi HEA was fabricated through TIG cladding. • MEA developed in the first and second layers owing to the substrate dilution. • MEA composition deviated far from HEA composition but no IMCs appeared. • Fe–Cr and Al–Ni pairs had contrary effect on stabilizing BCC/FCC in MEA and HEA. • Microhardness of the deposited layers increased successively to reach 430 HV in HEA. [ABSTRACT FROM AUTHOR]

Abstract: The 1050 aluminum sheets are severely deformed by two passes of the constrained groove pressing (CGP) process to obtain the strain of 2.32. Friction stir processing (FSP) is then performed on these specimens at two conditions of with and without SiC nanoparticles. Microhardness measurements indicate that in the state of FSP without any particle, the microhardness of stir zone is decreased due to the recrystallization and grain growth occurrence because of high stored strain energy in the CGPed specimens. In order to enhance the mechanical properties of the stir zone, SiC nanoparticles are used during FSP. Also, the effect of FSP pass number on the distribution of nanoparticles is investigated. Microstructure investigations reveal that after 1 and 2 passes of FSP with SiC nanoparticles, specimens experience brittle fracture at the retreating side of the stir zone during transverse tensile test due to the presence of clustered nanoparticles in this region. However, it is found that after 3 passes of FSP, SiC nanoparticles are uniformly distributed leading to the prohibition of grain growth in the stir zone. This can be responsible for the improvement of stir zone microhardness by about 118.8% with respect to the specimen FSPed without nanoparticles. [Copyright &y& Elsevier]

Abstract: The severely deformed aluminum sheets with strain of 2.32 were successfully joined by friction stir welding (FSW) process. Welding was carried out at various rotation speeds of 600, 800, and 1000rpm at traveling speed of 200mm/min corresponding to various revolution pitches of 0.33, 0.25, and 0.20mm/r, respectively. In order to investigate the thermal stability of the joints, annealing was carried out at temperature of 200°C for 1h. Microstructure examinations revealed that severely deformed samples were quite unstable upon FSW process. However, during annealing it was found that in contrast to regions of heat affected zone (HAZ) and thermo mechanical affected zone (TMAZ) where recrystallization and grain growth occurred, grain growth did not mainly occur at the stir zone showing the thermal stability of this area. Also, the mechanical properties of joints in as-welded and annealed conditions were examined. The microhardness measurements and transverse tensile tests were carried out. It was observed that all joints were fractured from TMAZ and stir zone interface. [Copyright &y& Elsevier]

Abstract: The microstructure evolutions of severely deformed aluminum sheets by Constrained Groove Pressing (CGP) after Friction Stir Welding (FSW) are investigated. To do so, the specimens are deformed in three different strains using CGP process which make different the initial microstructures. Then, the specimens are joined at various revolution pitches (traveling speed/rotation speed ratio) of 0.20, 0.25 and 0.33mm/r. To understand the effect of initial strains on the properties of joints, the microhardness measurements and microstructure investigations of different areas from retreating to advancing sides of the joints are carried out. The results achieved from FSW of CGPed samples are compared with those achieved from FSW of as-annealed ones (0 pass). It is found that in contrast to 2 passes CGPed specimens, for specimens strained by 1 pass of CGP process after FSW at low revolution pitch, the grain size at the center of stir zone is finer than that at around of stir zone center. Also, it is revealed that for CGPed samples in contrast to as-annealed ones, some recrystallized grains are formed in HAZ. Moreover, the amount of recrystallized grains in HAZ is different at advancing and retreating sides. [Copyright &y& Elsevier]

Lactobacillus plantarum, as a potential lactic acid and protease producer, was used for biological extraction of chitin from shrimp shell. L. plantarum was grown in a batch culture containing shrimp shell powder and date syrup, incubated at 30 °C. The produced organic acids and proteases in L. plantarum culture were able to demineralize and deproteinize shrimp shell. Percentages of deproteinization and demineralization were 45 and 54, respectively. In post treatment of the sample, dilute acid and alkali, were implemented to produce the specific chitin. Chitin was converted to chitosan by N-deacetylation with NaOH solution. Percentage of deacetylation based on FTIR spec-trum was 83 %. [ABSTRACT FROM AUTHOR]

Abstract: The severely plastic deformed aluminum sheets were joined by friction stir welding (FSW). The technique used for imposing the severe strain to the sheets was constrained groove pressing (CGP) process. The specimens with three different imposed strains by CGP, which lead to different initial microstructures, were joined at various rotation (ω) and traveling (V) speeds. The microhardness measurements and microstructure investigations were carried out. It was revealed that after FSW process of the specimens strained by CGP process, grain growth and correspondingly hardness reduction were observed at the stir zone. Also, transverse tensile test was performed at all conditions. For the CGPed samples, it has been observed that with increasing the rotation speed, the strength of weld was decreased while the effect of traveling speed on the strength was different at various strains. Furthermore, the results achieved from FSW of severely deformed samples were compared with the results achieved from FSW of annealed ones. [Copyright &y& Elsevier]

To evaluate the efficacy of sildenafil in the treatment of neurogenic erectile dysfunction (ED) secondary to upper motor neuron (UMN) and lower motor neuron (LMN) spinal cord injury (SCI). After taking consents 105 patients suffering from ED were enrolled in this prospective study. Seventy-two patients had signs and symptoms of UMN and 33 patients had signs and symptoms of LMN or mixed (UMN and LMN) spinal cord injuries. The patients took 50-100 mg sildenafil or placebo tablet at least 45 min before sexual intercourse. Based on a IIEF questionnaire, success in achieving erection adequate for sexual intercourse was compared between sildenafil and placebo groups in UMN and non-UMN spinal cord injuries. In patients with UMN disease, sildenafil was effective in 82% of patients and its efficacy was statistically higher than placebo (82 vs. 25%, p < 0.05). Twenty-eight per cent of patients with non-UMN disease had a favourable response to sildenafil that was not statistically different from placebo. Sildenafil seems more effective in the treatment of neurogenic ED secondary to UMN spinal cord injury compared with that secondary to LMN injury. Actually, its efficacy on LMN injuries does not seem different from placebo and administration of this treatment may not be effective in spinal cord injury which has caused LMN symptoms. [ABSTRACT FROM AUTHOR]

The most general nonuniform reaction-diffusion models on a one-dimensional lattice with boundaries, for which the time evolution equations of correlation functions are closed, are considered. A transfer matrix method is used to find the static solution. It is seen that this transfer matrix can be obtained in a closed form, if the reaction rates satisfy certain conditions. We call such models superautonomous. Possible static phase transitions of such models are investigated. At the end, as an example of superautonomous models, a nonuniform voter model is introduced, and solved explicitly. [ABSTRACT FROM AUTHOR]

The large-N behavior of the quartic-cubic generalized two dimensional Yang-Mills U(N) on the sphere is investigated for small cubic couplings. It is shown that single transition at the critical area, which is present for the quartic model, is split into two transitions; both of them are third order. The phase diagram of the system for small cubic couplings is obtained. [ABSTRACT FROM AUTHOR]

In two-dimensional Yang–Mills and generalized Yang–Mills theories for large gauge groups, there is a dominant representation determining the thermodynamic limit of the system. This representation is characterized by a density, the value of which should everywhere be between zero and one. This density itself is determined by means of a saddle-point analysis. For some values of the parameter space, this density exceeds one in some places. So one should modify it to obtain an acceptable density. This leads to the well-known Douglas–Kazakov phase transition. In generalized Yang–Mills theories, there are also regions in the parameter space where somewhere this density becomes negative. Here too, one should modify the density so that it remains nonnegative. This leads to another phase transition, different from the Douglas–Kazakov one. Here the general structure of this phase transition is studied, and it is shown that the order of this transition is typically three. Using carefully-chosen parameters, however, it is possible to construct models with the order of the phase transition not equal to three. A class of these non-typical models is also studied. [ABSTRACT FROM AUTHOR]

A system of particles is studied in which the stochastic processes are one-particle type-change (or one-particle diffusion) and multi-particle annihilation. It is shown that, if the annihilation rate tends to zero but the initial values of the average number of the particles tend to infinity, so that the annihilation rate times a certain power of the initial values of the average number of the particles remain constant (the double scaling) then if the initial state of the system is a multi-Poisson distribution, the system always remains in a state of multi-Poisson distribution, but with evolving parameters. The large time behavior of the system is also investigated. The system exhibits a dynamical phase transition. It is seen that for a k-particle annihilation, if k is larger than a critical value kc, which is determined by the type-change rates, then annihilation does not enter the relaxation exponent of the system; while for k < kc, it is the annihilation (in fact k itself) which determines the relaxation exponent. [ABSTRACT FROM AUTHOR]

The large-N behavior of Yang–Mills and generalized Yang–Mills theories in the double-scaling limit is investigated. By the double-scaling limit, it is meant that the area of the manifold on which the theory is defined, is itself a function of N. It is shown that phase transitions of different orders occur, depending on the functional dependence of the area on N. The finite-size scalings of the system are also investigated. Specifically, the dependence of the dominant representation on A, for large but finite N is determined. [ABSTRACT FROM AUTHOR]

Abstract: The large-N limit of the expectation values of the Wilson loops in the fundamental representation, corresponding to two-dimensional Yang–Mills and generalized Yang–Mills theories on a sphere are studied. The behavior of the expectation values of the Wilson loops both near the critical area and for large areas are investigated. It is shown that the expectation values of the Wilson loops at large areas behave exponentially with respect to the area of the smaller region the boundary of which is the loop; and for the so-called typical theories, the expectation values of the Wilson loops exhibit a discontinuity in their second derivative (with respect to the area) at the critical area. [Copyright &y& Elsevier]

The most general one dimensional reaction-diffusion model with nearest-neighbor interactions solvable through the empty interval method, and without any restriction on the particle-generation from two adjacent empty sites is studied. It is shown that turning on the reactions which generate particles from two adjacent empty sites, results in a gap in the spectrum of the evolution operator (or equivalently a finite relaxation time). [ABSTRACT FROM AUTHOR]

A two-parameter family of discrete-time exactly-solvable exclusion processes on a one-dimensional lattice is introduced, which contains the asymmetric simple exclusion process and the drop-push model as particular cases. The process is rewritten in terms of boundary conditions, and the conditional probabilities are calculated using the Bethe-ansatz. This is the discrete-time version of the continuous-time processes already investigated in [1-3]. The drift- and diffusion-rates of the particles are also calculated for the two-particle sector. [ABSTRACT FROM AUTHOR]

The large-N limit of the two-dimensional Yang–Mills theory on an arbitrary orientable compact surface with boundaries is studied. It is shown that if the holonomies of the gauge field on boundaries are near the identity, then the critical behavior of the system is the same as that of an orientable surface without boundaries with the same genus but with a modified area. The difference between this effective area and the real area of the surface is obtained and shown to be a function of the boundary conditions (holonomies) only. A similar result is shown to hold for the group and other simple groups. [Copyright &y& Elsevier]

The evolution of the two-point functions of autonomous one-dimensional single-species reaction-diffusion systems with nearest-neighbor interaction and translationally-invariant initial conditions is investigated. It is shown that the dynamical phase structure of such systems consists of five phases. As an example, a one-parameter family is introduced which can be in each of these phases. [ABSTRACT FROM AUTHOR]

A family of multispecies drop-push systems on a one-dimensional lattice is investigated. It is shown that this family is solvable in the sense of the Bethe ansatz, provided a nonspectral matrix equation is satisfied. The large-time behavior of the conditional probabilities, and the dynamics of the particle-type change are also investigated. [ABSTRACT FROM AUTHOR]

The Klein–Gordon and Dirac equations in a semi-infinite lab (x>0), in the background metric ds2=u2(x)(−dt2+dx2)+dy2+dz2, are investigated. The resulting equations are studied for the special case u(x)=1+gx. It is shown that in the case of zero transverse-momentum, the square of the energy eigenvalues of the spin-1/2 particles are less than the squares of the corresponding eigenvalues of spin-0 particles with same masses, by an amount of mgℎc. Finally, for non-zero transverse-momentum, the energy eigenvalues corresponding to large quantum numbers are obtained and the results for spin-0 and spin-1/2 particles are compared to each other. [Copyright &y& Elsevier]

The fabrication of metal-matrix composites by means of friction stir processing (FSP) has been the subject of many researches. However, the majority of works employed a method in which added particles are preplaced within a groove cut at the surface of a substrate. In the present study, a new method for the fabrication of AA6061/AlCoCrFeNi high-entropy alloy (HEA) surface composite has been introduced that could be more practical in industries. For this purpose, AlCoCrFeNi HEA powders were produced by mechanical alloying (MA) under various processing times, affecting the extent of alloying as well as the final size of particles. The powders were deposited on the surface of the substrate employing thermal spraying process, followed by FSP. The results indicated that a dual-phase of BCC and FCC crystal structure was formed during MA after 30 h of milling. During thermal spraying, Al and Cr partially left the alloyed powders to form oxides. This issue is more prominent in the case of MA for 30 h. Some cracks and porosities were also observed in the sprayed coating. The FSP was found practicable to eliminate these defects. Additionally, it caused the HEA powders to disperse well in the stir zone, achieving surface composite. Microstructural examinations revealed the diffusion of Al from matrix to the HEA phases, possibly leading to an increase in the entropy value of the distributed phase. Microhardness values of the stir zone was approximately three times more than those of the base metal in the case of MA under 20 h due to the new structure obtained. • Aluminum-matrix composite reinforced by high-entropy alloy particles was produced by thermal spraying and FSP. • HEA particles were obtained with mechanical alloying under different processing times. • Increasing the milling time led to formation of finer HEA particles, more susceptible to oxidation during thermal spraying. • FSP was found suitable for distribution of HEA particles within the Al matrix, obtaining surface composite. • The microhardness of processed sample was three times more than that of the substrate. [ABSTRACT FROM AUTHOR]

We generalize the Maldacena correspondence to the logarithmic conformal field theories. We study the correspondence between field theories in (d + 1)-dimensional AdS space and the d-dimensional logarithmic conformal field theories in the boundary of AdS[sub d+1]. Using this correspondence, we get the n-point functions of the corresponding logarithmic conformal field theory in d-dimensions. [ABSTRACT FROM AUTHOR]

Studies the equivalence of Darmois-Israel and distributional method for thin shells in general relativity. Familiar field equations and jump conditions of Darmois-israel formalism; Analysis of the Bianchi identities.

Assuming a continuous ansatz for the metric the Einstein equations for a thin wall with cylindrical symmetry are solved herein. The solution can correspond to a collapsing matter shell leading to a naked, without horizon, singularity. [ABSTRACT FROM AUTHOR]

The objective of this study is to investigate both the contact area and the interfacial separation between two surfaces. Both surfaces are considered to be rough, one of them being elastic and the other one hard. The work is based on an extended version of Persson's model of contact mechanics to study the behavior of the contact area, the interfacial separation and the pressure distribution. The results are compared with the case merely the hard substrate is rough. It is seen that introducing a roughness in the elastic surface decreases the real contact, if the surfaces are uncorrelated. A positive (negative) correlation increases (decreases) the real contact. A reverse pattern occurs for the width of the pressure distribution, as well as the interfacial separation (at equal pressures). [ABSTRACT FROM AUTHOR]

The structure of transition amplitudes in field theory in a three-dimensional space whose spatial coordinates are noncommutative and satisfy the SU(2) Lie algebra commutation relations is examined. In particular, the basic notions for constructing the observables of the theory as well as subtleties related to the proper treatment of δ distributions (corresponding to conservation laws) are introduced. Explicit examples are given for scalar field theory amplitudes in the lowest order of perturbation. [ABSTRACT FROM AUTHOR]

The most general reaction-diffusion model on a Cayley tree with nearest-neighbor interactions is introduced, which can be solved exactly through the empty-interval method. The stationary solutions of such models, as well as their dynamics, are discussed. Concerning the dynamics, the spectrum of the evolution Hamiltonian is found and shown to be discrete, hence there is a finite relaxation time in the evolution of the system towards its stationary state. [ABSTRACT FROM AUTHOR]

It is known that discrete scale invariance leads to log-periodic corrections to scaling. We investigate the correlations of a system with discrete scale symmetry, discuss in detail possible extension of this symmetry such as translation and inversion, and find general forms for correlation functions. [Copyright &y& Elsevier]

There have been some controversies about the large N behaviour of the 2-D Yang–Mills and chiral 2-D Yang–Mills theories. To be more specific, is there a one-parameter family of minima of the free energy in the strong region, or is the minimum unique? We show that by adding an equation (which was missing) to the known equations, the minimum becomes unique. [ABSTRACT FROM AUTHOR]

The Casimir force between two rough surfaces grown through statistical growth models is studied, both theoretically and numerically. The models include the random deposition (RD), the random deposition with surface relaxation (RDSR), and the restricted solid-on-solid growth (RSOS). To calculate the Casimir force, the pairwise summation (PWS) method in (2 + 1) dimensions is used. First, the force between two growing surfaces with RD equations, Edwards–Wilkinson, (EW) and Kardar–Parisi–Zhang (KPZ) equations is theoretically investigated. Then, using the Monte Carlo simulation, the rough surfaces with RD, RDSR, and RSOS models in (2 + 1) dimensions are simulated in different growth times, and the Casimir force between each pair of rough surfaces in each time step is calculated. The results show that the force between the surfaces increases as the roughness increases. [ABSTRACT FROM AUTHOR]

Background: Cardiovascular disease (CVD) is the principal cause of mortality and disability in Iranian adults. We aimed to evaluate the relationship between dietary patterns and CVD incidence in a large sample of adults in northeastern Iran. Methods: The present study comprised a prospective study of 5706 CVD‐free men and women aged 35–65 years who participated in a cohort study. All of the participants were followed up for a 6‐year period. Dietary patterns were derived from a 65‐item validated food frequency questionnaire and the factor analysis method was used to determine dietary patterns. Results: We identified two major dietary patterns: (i) a Balanced dietary pattern (a high intake of green leafy vegetables, other vegetables, fruits, dairy products, red meats, poultry, seafoods, legumes and nuts, as well as a low intake of sugar) and (ii) a Western dietary pattern (a high intake of sugar, tea, egg, snacks, fast foods, potato, carbonated beverages, pickled foods, organs meat and butter) by factor analysis. The hazard ratio (HR) and 95% confidence intervals (CIs) of total CVD in the highest versus lowest tertiles of the Balanced pattern were 1.29 (95% CI = 0.67–2.47; P = 0.44). The HR and 95% CIs of CVD in the highest versus lowest tertiles of Western pattern were 2.21 (95% CI = 1.08–4.45; P = 0.03). Conclusions: During the 6‐year follow‐up, we found that adherence to a Balanced dietary pattern was not significantly associated with CVD events. However, adherence to a Western dietary pattern was associated with a significantly increased risk of CVD events and its associated risk. [ABSTRACT FROM AUTHOR]

We describe the operations concept and data reduction plan for the Mid-Infrared Instrument (MIRI) for the James Webb Space Telescope (JWST). The overall JWST operations concept is to use observation templates (OTs) to provide a straightforward and intuitive way for users to specify observations. MIRI has four OTs that correspond to the four observing modes: (1) imaging, (2) coronagraphy, (3) low-resolution spectroscopy, and (4) medium-resolution spectroscopy. We outline the user choices and expansion of these choices into detailed instrument operations. The data reduction plans for MIRI are split into three stages, where the specificity of the reduction steps to the observation type increases with stage. The reduction starts with integration ramps: stage 1 yields uncalibrated slope images; stage 2 calibrates the slope images; and then stage 3 combines multiple calibrated slope images into high-level data products (e.g., mosaics, spectral cubes, and extracted source information). Finally, we give examples of the data and data products that will be derived from each of the four different OTs. [ABSTRACT FROM AUTHOR]

Background/Objective: Radioembolization (RE) is a minimally invasive transcatheter therapy through which radioactive microspheres are infused into the hepatic arteries and selectively implanted within the tumor arterioles. Some therapeutic agents are particles incorporating pure β emitter elements (90Y, 32P) and do not have gamma radiation. Bremsstrahlung imaging of these radiotherapeutic agents confirms distribution of the radiotracer in hepatic tumors or probable extrahepatic deposition of radiopharmaceuticals and helps the physician to predict the patient's response to RE therapy. The aim of this study was demonstration of 32P images and its correlation with CT/MRI findings. Patients and Methods: Ten patients with variable types of hepatic tumors treated with intraarterial injection of 32P were included in this study. 24-72 hours after radiotracer administration, bremsstahlung SPECT imaging was performed in all patients with a single head gamma camera equipped with a medium energy collimator. Energy window setting of 100 keV±25% was selected. Reconstructed images were evaluated by two nuclear medicine specialists and one radiologist, and based on compatibility of 32P images with CT/MRI, a grading scale from 1 to 4 was used to express their correlations. Results: By selecting optimized parameters for bremsstrahlung SPECT images of 32P, we could obtain good quality images. In nine patients, 32P distribution in the liver was correlated with anatomical findings of CT/MRI. Conclusion: RE is appropriate to deliver high radiation doses to liver tumors with minimal accumulation in the normal liver tissue. Bremsstrahlung imaging is a useful method to confirm proper distribution of the radiotherapeutic agent, which has good correlation with anatomical findings. [ABSTRACT FROM AUTHOR]

A letter to the editor is presented in response to the article "Effect of Forward Shoulder Posture on Pulmonary Capacities of Women," by A. L. Harrison and colleagues in the July 2008 issue.