Antimicrobial resistance of Shigella spp. isolated from diarrheal patients in Zahedan

One of the great challenges in the treatment of infectious diseases is the resistance of pathogenic bacteria against antibiotics, and antibiotic resistance to Shigella is broadly observed in different parts of the world. The object of this study was to determine Shigella antibiotic resistance pattern against the antibiotics such as ampicillin, amoxicillin, trimethoprim-sulfamethoxazole, chloramphenicol, nalidixic acid, ciprofloxacin and ceftriaxone. In this cross-sectional study, a total of 147 Shigella strains were collected from the diarrheic patients referring to different medical centers of Zahedan. Specific antisera were used for serotyping of isolated Shigella and their antibiotic resistance patterns were determined by standard Kirby-Bauer method. Of the 147 studied Shigella strains, 102 (69.3) belonged to S. flexneri, 32 (21.7) to S. dysenteriae, 11 (7.4) to S. boydii, and 2 (1.36) to S. sonnei species. The isolated strains showed resistance to ampicillin (99.3), trimethoprimsulfamethoxazole (52) and nalidixic acid (1.3), but there was no resistance against ciprofloxacin and ceftriaxone. According to the findings, it is suggested that antibiotics should not be used without laboratory testing (antibiogram). © 2008 Tehran University of Medical Sciences

Effect of Angipars on neuropathic pain in streptozotocin-induced diabetic rats

Introduction: Diabetes is the most common cause of peripheral nerve involvement. Evaluating the effect of antioxidants on diabetic neuropathic pain is important. This study aimed at evaluating the effects of Angipars medicine in the treatment of neuropathic hyperalgesia in single dose streptozotocin-induced diabetic rats. Methods: The study was performed on 50 Spraque dawley rats of 250-300 grams weight. The rats were divided into four groups of control, sham, Angipars-receiving diabetic, and vehicle-receiving diabetic, with at least 8 rats in each group. Diabetes was induced by intraperitoneal injection of 45 mg/kg streptozotocin dissolved in a 0.05 M citrate buffer. After confirming the diabetes, the diabetic rats received (5, 10, 20 mg/kg, intraperitoneal) Angipars and vehicle for 2 weeks. At the end of the eighth week, the control and treated rats were examined through the hot plate and tail flick tests. ANOVA was used to evaluate the statistical difference and P<0.05 was considered as significant. Results: At the end of the eighth week, the response time to thermal hyperalgesia decreased in the vehicle and sham groups compared with the control group. Angipars at doses of 5 and 10 mg increased the response time to thermal hyperalgesia compared to the vehicle and sham groups in hot plate test. In the tail flick test, 10mg Angipars increased the response time to pain similar to the control group. Conclusion: This study showed that, as an antioxidant, Angipars is capable of reducing neuropathic hyperalgesia in animals with diabetes

A comparison of numerical modelling techniques for tidal stream turbine analysis

To fully understand the performance of tidal stream turbines for the creation of ocean ren wable energy, a range of computational models is required. We review and compare results from several models at different length scales. Models under review include blade element momentum theory (BEMT), blade element actuation disk RANS-CFD, blade- resolved RANS-CFD and coastal models based on the shallow water equations. Three sets of experimental results are used for model validation

Traditional turbulence methods and novel visualisation techniques for coastal flow model in order to deploy tidal stream turbines

Characteristics of flow in the coastal regions are strongly influenced by the topography of the seabed and understanding of these features is necessary before installation of tidal stream turbines (TST). In this paper, the bathymetry of a potential TST deployment site is surveyed using an echosounder and the resulting data is used in the development of the geometric model. The steady state k-ɛ and transient Large Eddy Simulation (LES) turbulence methods are employed. The stream surface visualisation method employed has important inherent characteristics that can enhance the visual perception of complex flow structures [1]. In this method lighting and shading reinforce the perception of shape and depth, images or textures can be mapped to the surface primitives providing additional visual information, colour and transparency can be used to convey additional data attributes. The results of all cases are compared with the flow data transect gathered by Acoustic Doppler Current Profiler (ADCP). It has been understood that the k-ɛ method can predict the flow pattern with relatively good accuracy near the main features of the domain and the LES model has the ability to simulate some important flow patterns because of the bathymetry

Hundredfold Enhancement of Light Emission via Defect Control in Monolayer Transition-Metal Dichalcogenides

Two dimensional (2D) transition-metal dichalcogenide (TMD) based semiconductors have generated intense recent interest due to their novel optical and electronic properties, and potential for applications. In this work, we characterize the atomic and electronic nature of intrinsic point defects found in single crystals of these materials synthesized by two different methods - chemical vapor transport and self-flux growth. Using a combination of scanning tunneling microscopy (STM) and scanning transmission electron microscopy (STEM), we show that the two major intrinsic defects in these materials are metal vacancies and chalcogen antisites. We show that by control of the synthetic conditions, we can reduce the defect concentration from above $10^{13} /cm^2$ to below $10^{11} /cm^2$. Because these point defects act as centers for non-radiative recombination of excitons, this improvement in material quality leads to a hundred-fold increase in the radiative recombination efficiency

Computational prediction of pressure change in the vicinity of tidal stream turbines and the consequences for fish survival rate

The presence of Tidal Stream Turbines (TST) for tidal power production, leads to changes in the local physical environment that could affect fish. While other work has considered the implications with respect to conventional hydroelectric devices (i.e. hydroelectric dams), including studies such as physical impact with the rotors and pressure variation effects, this research considers the effects of sudden changes in pressure and turbulence on the hypothetical fish with respect to TSTs. Computational fluid dynamics (CFD) is used to investigate changes to the environment, and thus study the implications for fish. Two CFD methods are employed, an embedded Blade Element representation of the rotor in a RANS CFD model, and a blade resolved geometry using a moving reference frame. A new data interpretation approach is proposed as the primary source of environmental impact data; ‘rate of change of pressure’ with time along a streamtrace. This work also presents results for pressure, pressure gradients, shear rates and turbulence to draw conclusions about changes to the local physical environment. The assessment of the local impact is discussed in terms of the implications to individual fish passing a single or array of TST devices

Improved infeasibleinterior-point algorithm for linear complementarity problems

Abstract. We present a modified version of the infeasible-interiorpoint algorithm for monotone linear complementary problems introduced by Mansouri et al. (Nonlinear Anal. Real World Appl. 12(2011) 545-561). Each main step of the algorithm consists of a feasibility step and several centering steps. We use a different feasibility step, which targets at the µ + -center. It results a better iteration bound

NEW COMPLEXITY ANALYSIS OF A FULL NESTEROV-TODD STEPS IIPM FOR SEMIDEFINITE OPTIMIZATION Communicated by Nezam Mahdavi-Amiri

Abstract. In [H. Mansouri and C. Roos, Numer. Algorithms 52 (2009) 225-255.], Mansouri and Ross presented a primal-dual infeasible interior-point algorithm with full-Newton steps whose iteration bound coincides with the best known bound for infeasible interior-point methods. Here, we introduce a slightly different algorithm with a different search direction and show that the same complexity result is obtained using a simpler analysis

FUZZY GOAL PROGRAMMING TECHNIQUE TO SOLVE MULTIOBJECTIVE TRANSPORTATION PROBLEMS WITH SOME NON-LINEAR MEMBERSHIP FUNCTIONS

Abstract. The linear multiobjective transportation problem is a special type of vector minimum problem in which constraints are all equality type and the objectives are conflicting in nature. This paper presents an application of fuzzy goal programming to the linear multiobjective transportation problem. In this paper, we use a special type of nonlinear (hyperbolic and exponential) membership functions to solve multiobjective transportation problem. It gives an optimal compromise solution. The obtained result has been compared with the solution obtained by using a linear membership function. To illustrate the methodology some numerical examples are presented

A path-following feasible interior-point algorithm for mixed symmetric cone linear complementarity problems

Abstract In this paper, we propose a feasible interior-point algorithm for mixed symmetric cone linear complementarity problems which are a general class of complementarity problems. The symmetrization of the search directions used in this paper is based on Nesterov and Todd scaling scheme. By using Euclidean Jordan algebra, we prove the convergence analysis of the proposed algorithm and show that the complexity bound of the algorithm matches the currently best known iteration bound for feasible interior-point methods