Kharazmi University

About: Kharazmi University is a education organization based out in Tehran, Iran. It is known for research contribution in the topics: Membrane & Supply chain. The organization has 3395 authors who have published 5321 publications receiving 45645 citations. The organization is also known as: Tarbiat Moallem University of Tehran & Teacher Training University.

Biofilm formation in clinical isolates of nosocomial Acinetobacter baumannii and its relationship with multidrug resistance

Abstract: Objective To check biofilm formation by Acinetobacter baumannii (A. baumannii) clinical isolates and show their susceptibility to different antibiotics and investigate a possible link between establishment of biofilm and multidrug resistance. Methods This study was performed on clinical samples collected from patients with nosocomial infections in three hospitals of Tehran. Samples were initially screened by culture and biochemical tests for the presence of different species of Acinetobacter. Identifications were further confirmed by PCR assays. Their susceptibilities to 11 antibiotics of different classes were determined by disc diffusion method according to Clinical and Laboratory Standards Institute guidelines. The ability to produce biofilm was investigated using methods: culture on Congo red agar, microtiter plate, and test tube method. Results From the overall clinical samples, 156 specimens were confirmed to contain A. baumannii. The bacteria were highly resistant to most antibiotics except polymyxin B. Of these isolates, 10.26% were able to produce biofilms as shown on Congo red agar. However, the percentage of bacteria with positive biofilm in test tube, standard microtiter plate, and modified microtiter plate assays were 48.72%, 66.66%, and 73.72%, respectively. At least 92% of the biofilm forming isolates were multidrug resistant. Conclusions Since most of the multidrug resistant strains produce biofilm, it seems necessary to provide continuous monitoring and determination of antibiotic susceptibility of clinical A. baumannii. This would help to select the most appropriate antibiotic for treatment.

A novel imperialist competitive algorithm for generalized traveling salesman problems

Abstract: A hybrid imperialist competitive algorithm is presented.It uses assimilation, destruction/construction and imperialist development schemes.The algorithm is calibrated using Taguchi method.For evaluation, it is compared against two effective existing algorithms. This paper deals with generalized traveling salesman problems. In this problem, all nodes are partitioned into some clusters and each cluster must be visited exactly once in a tour. We present an effective metaheuristic method hybridized with a local search procedure to solve this problem. The proposed algorithm is based on the imperialist competitive algorithm (ICA), which is a new socio-politically motivated global search strategy. ICA is enhanced by a novel encoding scheme, assimilation policy procedure, destruction/construction operator and imperialist development plans. Various parameters of the algorithm are analyzed to calibrate the algorithm by means of the Taguchi method. For the evaluation of the proposed algorithm, it is compared against two effective existing algorithms through a set of available instances. The results demonstrate the superiority of our algorithm in both solution quality and robustness of the solution.

The Boubaker polynomials and their application to solve fractional optimal control problems

Abstract: In this paper, we focus on Boubaker polynomials in fractional calculus area and obtain the operational matrix of Caputo fractional derivative and the operational matrix of the Riemann–Liouville fractional integration for the first time. Also, a general formulation for the operational matrix of multiplication of these polynomials has been achieved to solve the nonlinear problems. Then, these matrices are applied to solve fractional optimal control problems directly. In fact, the functions of the problem are approximated by Boubaker polynomials with unknown coefficients in the constraint equations, performance index and conditions. Thus, a fractional optimal control problem converts to an optimization problem, which can then be solved easily. Convergence of the algorithm is proved. Numerical results are given for several test examples to demonstrate the applicability and efficiency of the method.

β-lactoglobulin-pectin Nanoparticle-based Oral Drug Delivery System for Potential Treatment of Colon Cancer.

Abstract: Colon cancer is one of the most common internal malignancies, and conventional chemotherapy is not effective in its treatment. Nanoparticles hold tremendous potential as an effective drug delivery system. The physicochemical properties of β-lactoglobulin, the main whey protein of cow's milk, such as its stability at low pH, its resistance to gastric protease, and its ability to bind hydrophobic ligands, give it potential for transporting drugs specifically for colon cancer. In the present research, β-lactoglobulin-pectin nanoparticles were designed to transfer a newly synthesized, anticancer platinum complex (bipyridine ethyl dithiocarbamate Pt(II) nitrate), to the colon. The effects of multiple factors on the size and the colloidal stability of the nanoparticles were studied using dynamic light scattering and scanning electron microscopy techniques. Results showed that the best particle size and highest colloidal stability were obtained in phosphate buffer, pH 4.5, with 0.5 mg/mL β-lactoglobulin and 0.025-0.05wt% pectin. The drug release profile in simulated gastrointestinal conditions demonstrated that β-lactoglobulin with a secondary coating is stable in acidic conditions but is able to release its cargo at pH 7. Hence, these nanoparticles have potential to serve as novel and effective vehicles for oral drug delivery preparations.