A nanoparticulate raloxifene delivery system based on biodegradable carboxylated polyurethane: Design,optimization, characterization,and in vitro evaluation

Biodegradable carboxylated polyurethanes with three molecular weights were synthesized to prepare a nanoparticulate sustained delivery system of raloxifene hydrochloride, the drug with poor bioavailability. The nanoparticles were prepared by coprecipitation method. Optimal conditions for the preparation of nanoparticles were obtained using Box–Behnken design. Independent factors were ratio of polymer to drug, M_w of polymer and speed of magnetic stirrer. Dependent variables include zeta potential, polydispersity index (PdI), particle size, and loading efficacy (LE). Results of the fractional factorial design based on an analysis of variance demonstrated that the model for particle size, zeta potential, PdI and loading efficacy was statistically significant. The size of nanoparticles in design experiments were 46–96 nm in diameter and had entrapment efficiency of 84–92%. The nanoparticles were evaluated for in vitro release and showed a sustained release profile (24.19% ± 4.35% after 4 weeks), following the Fickian diffusion‐based release mechanism. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39668.     

Optimal power‐aware relay placement for cooperative wireless sensor networks

We study the problem of optimizing the symbol error probability (SEP) performance of cluster‐based cooperative wireless sensor networks. Recent studies in literature show that an efficient relay selection protocol based on simple geographical information of the nodes to execute cooperative diversity can significantly improve the SEP performance at the destination of such networks. As well, similar line of research on optimal power allocation (for the source and relay nodes) can be found in literature. However, to achieve the best SEP performance at the destination of a cooperative wireless sensor network, joint optimization of power allocation and relay placement should be accomplished. To this aim, we reformulate the SEP of a multi‐hop cooperative communication in a general form and optimize transmitted power level and relay placement simultaneously. This analysis is developed for both amplify‐and‐forward and decode‐and‐forward relaying protocols. Simulation results demonstrate that the proposed joint optimization can effectively improve the SEP performance of the network. Copyright © 2013 John Wiley & Sons, Ltd.     

Stress–strain time-dependent behavior of A356.0 aluminum alloy subjected to cyclic thermal and mechanical loadings

This article presents the cyclic behavior of the A356.0 aluminum alloy under low-cycle fatigue (or isothermal) and thermo-mechanical fatigue loadings. Since the thermo-mechanical fatigue (TMF) test is time consuming and has high costs in comparison to low-cycle fatigue (LCF) tests, the purpose of this research is to use LCF test results to predict the TMF behavior of the material. A time-independent model, considering the combined nonlinear isotropic/kinematic hardening law, was used to predict the TMF behavior of the material. Material constants of this model were calibrated based on room-temperature and high-temperature low-cycle fatigue tests. The nonlinear isotropic/kinematic hardening law could accurately estimate the stress–strain hysteresis loop for the LCF condition; however, for the out-of-phase TMF, the condition could not predict properly the stress value due to the strain rate effect. Therefore, a two-layer visco-plastic model and also the Johnson–Cook law were applied to improve the estimation of the stress–strain hysteresis loop. Related finite element results based on the two-layer visco-plastic model demonstrated a good agreement with experimental TMF data of the A356.0 alloy.     

The chronobiology and clinical efficacy of Daflon in the treatment of chronic venous insufficiency

Improvement of methods for diagnosis and treatment of myocardial infarction and its complications permitted the mortality and disability resulting from this condition to be considerably reduced. The aim of the study was to analyse in retrospect clinical and functional disorders in subjects with a history of ventricular fibrillation in the acute phase. Over 3 years, 1096 patients with acute myocardial infarction had been admitted to the Department of Cardioresuscitation. Ventricular Fibrillation was cause of death in 2.1% of cases. Over this time period, resuscitation was a success in 2.9%. The following item was found out to be a factor of unfavourable prognosis during the first two years after development of acute myocardial infarction: it was postinfarction dilatation of the left ventricle having a part in the evolution of cardiac insufficiency and contributing to formation of arrhythmogenic substrate and, to a lesser degree, to ventricular fibrillation in the acute phase.     

A risk model approach to the prediction of fetal acidemia

OBJECTIVES: To compare clinical features, pulmonary function and high-resolution computed chest tomography (HRCT) findings of asthmatic patients with a component of incomplete reversibility of airflow obstruction (AIRAO) with those of patients with smoking-induced chronic obstructive pulmonary disease (COPD). METHODS: Thirteen patients with COPD (six males and seven females, mean age 59 years, mean smoking 50.5 pack-years) and 14 patients with AIRAO (six males and eight females, mean age 52 years) despite optimal treatment, with no significant smoking history (mean 1.5 pack-years) and no significant environmental exposure or any other respiratory disease, were studied. Patients had respiratory questionnaires, pulmonary function tests, allergy skin-prick tests and an HRCT to evaluate possible parenchymal or bronchial abnormalities. Eight patients in each group also had exercise tests. All patients were stable at the time of the study. RESULTS: As expected, atopy was more prevalent in AIRAO (n=13) than in COPD (n=1) patients. Mean forced expiratory volume in 1 s (FEV1) and forced vital capacity (percentage of predicted value) were 39% and 61%, respectively, in COPD patients and 49% and 71%, respectively, in AIRAO patients; FEV1 improved by 18% in COPD patients and and by 22% in AIRAO patients after use of inhaled salbutamol. Mean functional residual capacity was greater in COPD patients than in AIRAO patients (178% versus 144% of the predicted value), while the mean carbon monoxide diffusing capacity of the lungs (DLCO) was lower in COPD patients than in AIRAO patients (62% versus 89% of the predicted value). Exercise tolerance was similar in both groups, as were postexercise changes in arterial oxygen pressure (PaO2). Emphysematous changes were observed in COPD patients and AIRAO patients who had evaluable HRCTs (10 versus two patients, although very mild in asthma), bronchial dilations (zero versus six patients), bronchial wall thickening (two versus eight patients) and an acinar pattern (one versus five patients). Mean thickness of the large airway wall to outer diameter (intermediary bronchus) ratio was 0.176 in COPD and 0.183 in AIRAO (P>0.05). CONCLUSIONS: Asthma may lead to physiological features similar to COPD but may be distinguished by demonstrating a preserved DLCO and a higher ratio of airway to parenchymal abnormalities on HRCT scan.     

Identification and control of continuous-time nonlinear systems via dynamic neural networks

In this paper, we present an algorithm for the online identification and adaptive control of a class of continuous-time nonlinear systems via dynamic neural networks. The plant considered is an unknown multi-input/multi-output continuous-time higher order nonlinear system. The control scheme includes two parts: a dynamic neural network is employed to perform system identification and a controller based on the proposed dynamic neural network is developed to track a reference trajectory. Stability analysis for the identification and the tracking errors is performed by means of Lyapunov stability criterion. Finally, we illustrate the effectiveness of these methods by computer simulations of the Duffing chaotic system and one-link rigid robot manipulator. The simulation results demonstrate that the model-based dynamic neural network control scheme is appropriate for control of unknown continuous-time nonlinear systems with output disturbance noise.     

II. Yeast sequencing reports. A putative P-type Cu2+-transporting ATPase gene on chromosome II of Saccharomyces cerevisiae

We have sequenced a gene on the right arm near the telomere of chromosome II of Saccharomyces cerevisiae which codes for a putative P-type cation-transporting ATPase (PCA1). The gene codes for a 1216 amino acids protein. The PCA1 gene expresses a 3·5 kb message in both haploid and diploid cells when grown in glucose-based rich medium YPD. The gene product is most similar at the C-terminal region to a human copper-transporting ATPase and Enterococcus hirae copper-transporting ATPases and also an N-terminal dithiol region that was proposed to be a ‘metal-binding motif’. Cells lacking PCA1 display no obvious phenotype when tested under standard conditions; whereas they cease growth much earlier than the isogenic wild-type cells in a minimal medium with high copper concentration. Overexpression of PCA1 under GAL1/10 promoter in yeast cells causes poor growth. We also show that yeast strains carrying PCA1 in multiple copies grow slower than isogenic wild-type strains in a minimal synthetic medium containing 0·3 mM-CuSO₄. The sequence has been deposited in the EMBL data library under Accession Number Z29332.     

Comparison of Molecular Techniques with other Methods for Identification and Enumeration of Probiotics in Fermented Milk Products

Nowadays, an increasing attention is being given to fermented milk products including yogurt, kefir, buttermilk, and acidophilus milk. Fermented milks, especially the ones containing probiotics, are claimed to be useful for health of host (such as intestinal- and immune-associated diseases). Their healthful effects could be significantly enhanced by incorporating probiotic microorganisms; those have healthful advantages for host when consumed in an appropriate viable number in food products. Probiotic dairy products have stepped to the market and are being commercially produced under various brand names. In addition, these products are legislatively obliged to be labeled for the microorganisms contained. Therefore, identification and enumeration of their microorganisms are a cause of concern. Several culture-dependent methods have been introduced and used to identify the microorganisms, in which the researchers have experienced multiple difficulties. Thereby, molecular approaches were present as an alternative, offering advantages such as accuracy, sensitivity, specificity, and speed. This article reviews the molecular approaches employed for identification and enumeration of probiotics in fermented milk products.     

Functionalization of SBA-15 by dithiooxamide towards removal of Co (II) ions from real samples: Isotherm,thermodynamic and kinetic studies

In this study, mesoporous SBA-15 was functionalized by dithiooxamide ligand through sodium dodecyl sulfate as intermediate. The obtained nanocomposite was considered as a strong adsorbent towards selective removal of the cobalt (II) ions from the industrial wastewater samples. Transmission Electron Microscopy (TEM) analysis, Brunauer-Emmett-Teller (BET) analysis, elemental CHNS (carbon, hydrogen, nitrogen, and sulfur) analysis, and thermo-gravimetric analysis (TGA) were used for characterization, particle size determination, confirming the presence of the used ligand, and measuring the nanocomposite stability, respectively. Effective parameters on the removal of the cobalt (II) ions such as pH, adsorbent dosage, concentration, and contact time have been evaluated. Results showed that the Freundlich isotherm has a bit better correlation coefficient compared to Langmuir isotherm (0.96 versus 0.94, respectively). The maximum amount of Co (II) ions adsorption on 1 g of nanocomposite (q_m) is calculated to be 2500 mg/g that points to the excellent adsorption. Kinetic analyses were conducted using pseudo-first and second-order models and the regression results showed that the pseudo-second-order model is more accurate for the study of the cobalt adsorption due to the higher correlation coefficient (0.99 versus 0.83) compared to the pseudo-first-order model. The result of the present study points that the suggested nanocomposite can be positively used in treating industrial effluents containing cobalt ions.