Development and Characterization of Peptidic Fusion Inhibitors Derived from HIV‐1 gp41 with Partial D‐Amino Acid Substitutions

Interactions between C34 and N36 : Synthetic peptides with D ‐amino acid substitutions that mimic the human immunodeficiency virus (HIV) gp41 HR2 region may lead to new peptidic anti‐HIV‐1 drugs that retain potent antiviral activity while being more resistant to proteolytic degradation.

     

Fabrication of ceramic micro-scale hollow components by micro-powder injection moulding

Rapid developments in microsystem technologies demand ceramic microcomponents of increasing geometrical complexity. State-of-the-art microfabrication routes of ceramics are either limited in geometrical complexity and/or high volume capabilities. This paper presents a process route by which ceramic microcomponents with relatively complex three-dimensional architectures could be realised by a high-volume technique. The proposed strategy, in which yttria-stabilised zirconia was implemented, combines the capabilities of insert-micromoulding, powder micro-overmoulding, catalytic debinding and sintering. The produced architectures demonstrate the capability of the technique to combine the high performance of ceramic materials with the dimensional accuracy and mass manufacturability of powder micromoulding.     

Laser assisted turning of Titanium Metal Matrix Composite

Although ceramic particles in Titanium Metal Matrix Composites (TiMMCs) improve its wear resistance properties, they also cause high abrasive tool wear. In an attempt to enhance tool life and productivity, Laser Assisted Machining (LAM) of TiMMC was performed under different cutting conditions, an aspect that has never been investigated before. Analysis of the results showed that LAM can significantly increase tool life by up to 180%. The phenomenon of improved tool life at higher speeds and under LAM conditions were explained through the analysis of the chip morphology and micro-structure.     

OS-CFAR and CMLD threshold optimization in distributed systems using evolutionary strategies

This paper proposes an improvement of the threshold optimization in distributed ordered statistics constant false alarm rate and censored mean level detector using Evolutionary Strategies (ESs). The target is assumed to be Rayleigh distributed and the observations are independent from sensor to sensor. Two fusion rules; “AND” and “OR” were considered. An ES was tested and a comparison with a genetic algorithm improved by a tournament selection was also analyzed. Among a variety of evolution strategies, the most popular proposed in the literature are the strategy (μ, λ) and the strategy (μ + λ). We proposed an (μ + λ) evolution strategy, by which a self-adaptation mutation is used. The results showed that, although the ES is more difficult to implement and is in a certain manner slower than the GA, it improves the performance of the system.     

Shaft misalignment effect on bearings dynamical behavior

The inherent problems of the rotating machine dysfunction are often caused by shaft misalignment. This defect generates some important loads and vibrations, and can lead to a premature failure of the bearing, the shaft, or the coupling. This work deals with the development of a theoretical model describing this phenomenon. This allows obtaining and analysing the vibration response as well as the reaction in bearings.     

Effects of diet supplementation with cactus pear seeds and oil on serum and liver lipid parameters in rats

The purpose of this investigation was to evaluate the effects of diets enriched with cactus pear oil (CPO) or seeds (CPS) on serum and liver lipid parameters compared to those of adult rats submitted to a standard diet. Male rats were divided into three groups, the first group represented control group, fed with standard diet, the second group was fed with control diet supplemented with CPO (2.5%, wt/wt) and the third group fed control diet supplemented with CPS (33%, wt/wt), for nine weeks. Feed intake and body weight of rats were measured every two days. Organ weights were determined at the end of treatment; cholesterol, HDL and triglycerides levels were determined by enzymatic methods. Liver and serum lipid extracts were analysed for their fatty acid composition for the three groups of rats. No differences in pancreas, kidney or liver weights were observed in the CPS diet whereas the CPO diet induced a significant increase in liver and pancreas weights. The tested diets significantly decreased the atherogenic index compared to the control diet, whereas serum cholesterol level was only reduced by the supplementation with CPO diet. No variations in serum lipids were observed among the groups, whereas liver lipids showed slight variations. Accordingly, these results indicated that the supplementation with CPO or CPS could be effective in decreasing the atherogenic risk factors in rats.     

Research of critical causes and improvement of energy storage system reliability in power electronic applications

In order to prevent the critical failures in lead acid batteries, the authors propose a new multistep current charge profile based on mathematical methods to calculate the charge current for each step according to the battery voltage variations and state of charge. The energy management system is developed in order to avoid the deep discharge that causes stratification of electrolyte, sulfating and deterioration of active mass. In addition, the electrodes corrosion and gassing phenomena are prevented by adopting a suitable charge cycle. In this paper, the causal tree analysis is used to identify the critical failure modes of battery and their causes in different applications such as uninterruptible power supply, renewable energy and hybrid electric vehicle. The identification of the degradation causes allows properly proposes some recommendations in order to extend the battery lifetime by adding suitable additives in the manufacturing process and adopting an appropriate charge cycle. The experimental result of the multistep current profile is realized with lead acid battery 90 Ah to investigate their efficiency to ensure the maximum battery reliability. This current profile avoids the corrosion phenomenon generated by overcharge and the sulfating phenomenon caused by an incomplete charge with a charging time depends on the number of the chosen step. Therefore, the multistep current profile is a suitable charge cycle that preserves the battery capacity and increases its lifetime.     

Experimental study of metal–hydrogen reactor behavior during desorption under heating by electromagnetic induction

The objective of this work is to study experimentally the behavior of a metal–hydrogen reactor (MHR) during hydrogen desorption by the LaNi₅ hydride. The reactor is surrounded by a small coil traversed by an alternative sinusoidal current. The effect of the voltage applied to the coil is studied. Two kinds of tests are done. In the first one, the reactor is heated to the desired temperature and then it was put in contact with a tank at weak pressure (desorption), and in the second one, desorption and heating start simultaneously. Desorbed mass and temperature evolution within the hydride bed and in the reactor wall, as a function of time, are plotted. A comparison of results obtained by the electromagnetic induction heater and by heat exchanger provisioned by a hot fluid shows an improvement of the efficiency of the reactor when compared to the traditional hot system (fluid system).     

Traditional Tunisian butter: Physicochemical and microbial characteristics and storage stability of the oil fraction

Physicochemical and microbiological characteristics, fatty acid composition and thermal stability of traditional Tunisian butter (TTB) were studied. Changes in microbiological and physicochemical parameters were monitored during storage at 4 and 10 °C. The physicochemical characterisation shows a fat level lower than 80% and a high value of water activity. The content of saturated fatty acid was higher (71.84%) than the unsaturated one (27.09%). The major fatty acids of butter samples were myristic, palmitic, stearic and oleic acids. During storage at 4 and 10 °C, the pH decreased and the titratable acidity increased. Counts of lactic acid bacteria exhibited relatively small changes upon storage, at 4 and 10 °C, whereas yeasts and moulds' counts increased irrespective of storage temperature. Effect of heating on some quality characteristics (absorption at 232 and 270 nm, peroxide value, free fatty acid content, viscosity, texture, colour and fatty acid composition) of traditional Tunisian butter oil (TTBO) has been investigated at 60 °C. Results show that TTBO was resistant to oxidation. All these characteristics consolidate the incorporation of TTB on food formulation.     

Cyclic changes in genital organs and vaginal cytology in cynomolgus monkeys (Macaca fascicularis)

Vaginal cytology was evaluated weekly over 12 months in 20 adult female Cynomolgus monkeys (Macaca fascicularis). After sacrifice of the animals the histology of the ovaries, uterus and vagina were studied in different phases of the menstrual cycle. The cytological examination of the vaginal smears showed that the superficial cells increased in number towards the middle of the cycle and the number of intermediate cells declined gradually. Parabasal cells were observed mainly at the beginning of the cycle; they disappeared towards the middle of the menstrual cycle. During the early follicular phase, the cells were moderately separated from each other, and during the second half of the proliferative or follicular phase, the superficial cells appeared clumped together. Leucocytes were usually absent except for at the beginning of the cycle and in the last few days of the late secretory or luteal phase. The maturation index of the vaginal smears can be considered as a tool for distinguishing the different phases of the menstrual cycle. The microscopic examination of the genital organs showed that during the proliferative or follicular phase of the cycle, which corresponds to the development of the ovarian follicles, the uterus showed growth of endometrial glands, stroma and endothelial cell proliferation with capillary sprouts. Shortly after ovulation and parallel to the formation of the corpora lutea, the endometrium enters the secretory or luteal phase, which is characterized by coiling of endometrial glands, glandular secretion and the differentiation of the spiral artery. The most striking changes in the vagina, is the marked basal cell proliferation and thickening of the stratum granulosum during the follicular phase of the menstrual cycle. The histological changes observed in the vagina demonstrated a good correlation with the observation on cytological examination of the smears. The present study demonstrated that the process of angiogenesis in the uterus during the different phases of the menstrual cycle is a multiple phenomenon involving proliferation, maturation and differentiation.