Morphological and Mechanical Characterization of Extracellular Vesicles and Parent Human Synoviocytes under Physiological and Inflammatory Conditions

The morphology of fibroblast-like synoviocytes (FLS) issued from the synovial fluid (SF) of patients suffering from osteoarthritis (OA), rheumatoid arthritis (RA), or from healthy subjects (H), as well as the ultrastructure and mechanical properties of the FLS-secreted extracellular vesicles (EV), were analyzed by confocal microscopy, transmission electron microscopy, atomic force microscopy, and tribological tests. EV released under healthy conditions were constituted of several lipid bilayers surrounding a viscous inner core. This “gel-in” vesicular structure ensured high mechanical resistance of single vesicles and good tribological properties of the lubricant. RA, and to a lesser extent OA, synovial vesicles had altered morphology, corresponding to a “gel-out” situation with vesicles surrounded by a viscous gel, poor mechanical resistance, and poor lubricating qualities. When subjected to inflammatory conditions, healthy cells developed phenotypes similar to that of RA samples, which reinforces the importance of inflammatory processes in the loss of lubricating properties of SF.     

A recursive hierarchical parametric estimation algorithm for nonlinear systems described by Wiener‐Hammerstein models

In this paper, a recursive hierarchical parametric estimation (RHPE) algorithm is proposed for stochastic nonlinear systems which can be described by Wiener‐Hammerstein (W‐H) mathematical models. The formulation of parameters estimation problem is based on the prediction error approach and the gradient techniques. The convergence analysis of the developed RHPE algorithm is derived using stochastic gradient‐based theory. Wiener‐Hammerstein hydraulic process is treated to prove the efficiency of the proposed approach.     

The more effective treatment of atrial fibrillation applying the natural compounds; as NADPH oxidase and ion channel inhibitors

Atrial fibrillation (AF) is the most common cardiac arrhythmia that occurs because of several different risk factors, e.g., valvular heart disease, coronary artery disease, age ≥75 years, hypertension and diabetes mellitus. One key risk factor that results in AF, is oxidative stress. Evidence suggests that there is a correlation between oxidative processes and the genesis of AF. Oxidative stress occurs when the generation of reactive oxygen species (ROS) increase due to excessive activity of enzymes including NADPH oxidase (NOX) and xanthine oxidase; or its degradation decrease by dysfunctional antioxidant enzyme systems, such as superoxide dismutase (SOD), catalase and glutathione peroxidase (GPx). Afterwards, elevated ROS may shift ion channel activity to increase AF susceptibility.

The outbreak of AF continues to grow. Unfortunately, current treatment strategies may have limited efficacy or adverse effects. On the other hand, the inhibition of ROS formation and alteration of ion channel activity could be important therapeutic targets for prevention or treatments of AF. Additionally, many studies have been shown that several natural compounds have the ability to inhibit NADPH oxidases directly. This review focuses on natural compounds which specially inhibit NOX isoforms and have direct effects on ion channels, suggesting these compounds can be helpful in AF treatment.     

Reflectance-yarn geometry relation of false-twist textured olive hue poly(ethylene terephthalate) mass dyed yarn in visible–near-infrared region

This study was conducted on the visible–near-infrared camouflage properties of olive hue poly(ethylene terephthalate) multifilament mass dyed yarn textured by two texturizing method (simultaneous and conventional). The effect of thermal process and structural changes on the reflectance, mechanical, and crimp properties of these yarns was studied using the DSC, XRD, and birefringence analyses. It was observed that simultaneously textured mass dyed multifilament yarns have higher crimp properties and lower mechanical properties. Furthermore, the effect of yarns’ geometry in the fabric structure on the reflectance properties was investigated using images of fabric structure. The results showed that the reflectance behavior of fabric sample is affected by two major factors, namely structural and geometrical factors; it is clear that the geometrical factor has a significant effect on the reflectance properties.     

Nutritional characteristics,biochemical composition and antioxidant activities of Moroccan Oat varieties

Oat has been recognized as a healthy food for a long time. In this study, physicochemical analysis including, moisture, pH, ash, fibres, proteins, starch, carbohydrates, some minerals, sugars, fatty acids, sterols, total phenolic, and flavonoid contents of four Moroccan Oat varieties (Amlal, Tissir, Zahri and Ghali) were investigated. Additionally, starch morphology has been described according to scanning electron microscopy, and viscosity as measured on a rotary rheometer, increased with stabilization time. Furthermore, Oat extracts were analyzed with regard to their antioxidant activities using DPPH radicals’ cation, Trolox equivalent antioxidant capacity and ferric reducing/antioxidant power. Results from this investigation demonstrated that Moroccan Oat varieties constitute an interesting supplement of natural antioxidants, especially phenolic compounds. Moreover, potassium was the main mineral in Oat seeds (1628.17–2541.52 mg/Kg); also, the oleic, linoleic, and palmitic acids were the dominant fatty acids. While the major sterols were, β-sitosterol, Δ-5-avenasterol and campesterol. Finally, sugar analysis by HPLC-RI indicate that sucrose content was higher than glucose and fructose respectively, and that Ghali and Amlal varieties exhibit an important total sugars levels. Those results highlight the possible contributions of Oat seeds to nutritional therapy.     

The pig caecum model: a suitable tool to study the intestinal metabolism of flavonoids

Pig caecum was used under anaerobic conditions to metabolize flavonoids from several classes, i.e., chrysin 1, naringenin 2, quercetin 3, and hesperetin 4. Whereas chrysin 1 was not converted by the pig intestinal flora under the experimental conditions used, naringenin 2 was transformed to 3-(4-hydroxyphenyl)-propionic acid and 3-phenylpropionic acid. Quercetin 3 was metabolized to phloroglucinol, 3,4-dihydroxyphenylacetic acid, and 3,4-dihydroxytoluene. Hesperetin 4 was degraded via eriodictyol to 3-(3-hydroxyphenyl)-propionic acid and phloroglucinol. Structural elucidation of the formed metabolites was performed by high-performance liquid chromatography--diode array detection (HPLC-DAD) as well as HPLC-electrospray ionization--mass spectrometry (ESI-MS (MS)) and high resolution gas chromatography-mass spectrometry (HRGC-MS) analyses. The time course of microbial conversion of 2-4 was determined by HPLC-DAD analysis, revealing slow degradation of 2 and rapid transformation of 3 and 4. The results lead to the conclusion that the pig caecum model is a suitable ex vivo model for studying the intestinal degradation of flavonoids.     

Study of hydrogen production by three strains of Chlorella isolated from the soil in the Algerian Sahara

In this study, the photosynthetic hydrogen production rates by some strains of green microalgae were investigated. Three strains of Chlorella isolated from arid soil and foggaras's water in the Algerian Sahara were used. Chlorella sorokiniana strain Ce, Chlorella salina strain Mt and Chlorella sp strain Pt6 produced hydrogen gas under sulphur-deprived conditions, but its rate was dependent on strain type and oxygen partial pressure in medium. In C. sorokiniana strain Ce, the maximum value of hydrogen accumulated was 147 ml at 222 h at 2% of O₂ pressure. Compared to C. sorokiniana strain Ce, C. salina strain Mt and Chlorella sp strain Pt6 produced less amount of hydrogen, but they were able to sustain with an O₂ partial pressure of up to 11–15.4%. Our data were compared with hydrogen production by Chlamydomonas reinhardtii. In this communication, the relationship between physiological behaviour, biochemical characteristic (starch and protein) and rates gas production (O₂ and H₂) was also specified.