Characterization of rheological and thermophysical properties of HDPE–wood composite

The objective of this study is to develop a new biocomposite material with high deformation ability. In this regard, the thermal, rheological, and thermophysical properties of this new composite were characterized as a function of temperature and filler concentration. High density polyethylene (HDPE) was the matrix of this new composite which was reinforced with six sawdust concentrations 0%, 20%, 30%, 40%, 50%, and 60%. Maleic anhydride grafted polyethylene (PE‐g‐MA) was used as coupling agent. Addition of sawdust with PE‐g‐MA increased significantly the complex viscosity, the storage modulus (G′), and loss modulus (G″) of the matrix. The superposition of the complex viscosity curves using temperature dependent shift factor, allowed the construction of a viscosity master curve covering a wide range of temperatures. Arrhenius law was used for the relationship of the shift factor to temperature. Furthermore, method of Van Gurp and Palmen (tan delta vs. G*) is also used to control the time–temperature superposition. The experimental results can be well fitted with the cross rheological model which allowed the prediction of the thermorheological properties of the composites over a broad frequency range. By increasing wood concentration, both the activation energy and relaxation time for the biocomposites determined using, respectively, the Arrhenius law and the cole–cole rule increased. By contrast, specific heat of the matrix decreased with sawdust addition while its dimensional stability improved. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40495.     

Modification of SiC precursors with an amine–borane complex

Two methods for preparing precursors of Si/C/B-based thermostructural materials have been developed. The first consists of a thermal treatment of a mixture of polydimethylsilane (PDMS), (Me2Si)n, and triethylamine–borane adduct, Et3N : BH3 at atmospheric pressure. The second involves two steps: (i) transformation of PDMS into a polymer displaying Si–CH2–Si and Si–Si linkages in its backbone, and (ii) heating this product at atmospheric pressure, in the presence of Et3N: BH3. The ceramic material obtained from the second approach contains 2.2 at% boron and 1.5 at% oxygen.     

Langerhans cells in Langerhans cell granulomatosis are not actively proliferating cells

Pulmonary Langerhans cell granulomatosis (LCG), also called histiocytosis X, is a disorder of unknown etiology characterized by the presence of destructive granulomas containing numerous Langerhans cells (LCs). The process may be localized or multifocal, and it remains unclear whether the same pathogenic mechanism is involved in all forms of the disease. It is often assumed that the massive accumulation of LCs at the sites of the lesions results from the abnormal proliferation of these cells, although it has been suggested that LCG in adults, at least in the lung, could be a reactive disorder initiated by activated LCs. Little is known, however, concerning the mechanisms responsible for the accumulation of large numbers of LCs in the course of the disease, and the relative contribution of recruitment and local proliferation of these cells remains to be established. To investigate this question, the proportion of replicating LCs was evaluated in biopsied granulomas from patients with localized or diffuse form of LCG by means of several histopathological techniques currently used in assessment of cell proliferation. The findings demonstrate that, except for proliferating cell nuclear antigen (PCNA), all parameters measured are low in all forms of the disease. They are similar to those of renewing epithelial cells and clearly less than those of neoplastic cells. These data strongly suggest that LCs in LCG granulomas are not a rapidly dividing cell population and that local LC replication makes only a minimal contribution to granuloma maintenance. Caution appears to be necessary in the use of PCNA as a marker of growth fraction.     

A novel,fast and accurate chemiluminescence method for measuring lipoxidation in almonds and almond-based products during processing and storage

An analytical method for investigating lipoxidation processes based on soft extraction and chemiluminescence (CL) detection methods was developed and tested on almond and almond-derived foodstuffs. The TBARS method, which detects any carbonyls generated by lipoxidation, was used for comparative purposes. When developing the present method, the classical chloroform–methanol procedure was first used to extract the CL reacting substances initially generated, and solubilizing agents were then screened for optimal extraction. In the detection stage, cytochrome C was used as a reference substance for screening the CL signal enhancers. The method presented here was based on an extraction step with a dimethylsulfoxide/Gum Arabic mixture, and hemin was used to enhance the luminescence signal. This method accurately detects the lipoxidation processes triggered by the physical and chemical treatments of all kinds which are applied during almond processing. The simultaneous use of the present method and the TBARS method gave a broader picture of the chemical interactions involved, including the lipoxidation process.     

Effects of light,temperature and water activity on the kinetics of lipoxidation in almond-based products

Lipoxidation in almond-derived products was investigated using the chemiluminescence (CL) and thiobarbituric acid-reactive substances (TBARS) methods to detect the first and later reaction products, respectively. The effects of light during storage at 5 °C, 22 °C and 40 °C were studied, as well as the effects of combined heat/water activity treatments in the 60–120 °C and 0.38–0.72 range. During storage, light was found to enhance the CL and TBARS values, and specific responses were observed in almond paste and the final Calisson product. During the heating of almond paste, as the initial water activity (a_w) increased, the CL rate constants increased during heating to 60 °C and 80 °C, but interestingly, these values decreased during further heating to 120 °C, whereas the maximum TBARS rate constants occurred at a_w 0.57 at all the heating temperatures tested. The activation energies, based on the CL and TBARS values, decreased specifically when the a_w increased from 0.38 to 0.72, giving overall values ranging from110 kJ mol⁻¹ to 60 kJ mol⁻¹. Likewise, in the same water activity range, the temperature-dependent rate constant enhancing factor (Q₁₀) decreased from 3.3 to 1.6.     

Protein kinase C alterations in aortic vascular smooth muscle cells from rats with cirrhosis

It was found that the frequency of extreme situations (traumas, deaths, sudden diseases) in miners working in Spitsbergen mines (74 degree N) correlates well with heliogeomagnetic activity (local magnetic disturbances, solar proton flashes). It was shown that in winter, both an enhanced and an extremely low level of magnetic activity can affect the occurrence of extreme situations. The results obtained can be used for predicting and reducing the frequency of extreme events in the zone of the polar cap during geomagnetic disturbances.     

Urogenital tuberculosis. Apropos of 40 cases

The authors report a series of 40 cases of genitourinary tuberculosis diagnosed and treated in the department of urology "B" of Avicenne hospital over a 7-year period. The objective of this study is to define the various diagnostic and therapeutic aspects of this disease. The patients were predominantly males (62.5%) with a mean age of 40 years. 25% of cases reported a history of extra-urinary tuberculosis. The very polymorphous clinical presentation is dominated by signs of cystitis (45%). Intravenous urography is frequently suggestive of the diagnosis based on the appearance and multiplicity of the lesions. The radiological lesions most frequently encountered were silent kidney (19 cases) and small tuberculous bladder (11 cases). The definitive diagnosis was established by pathological examination in 38 cases (biopsies, operative specimens, prostatic resection chips) and/or by demonstration of AFB in 2 cases (urine, pus). Tuberculostatic treatment was administered to all patients, either alone (5 cases) or, more usually, in combination with surgical and/or endo-urological treatment (35 cases), reflecting the magnitude and severity of the destructive and scar lesions.     

Altered growth and lack of responsiveness to angiotensin II in aortic vascular smooth muscle cells from cirrhotic rats

BACKGROUND & AIMS: In cirrhosis, increased amounts of circulating hormones such as angiotensin II may induce vascular tone changes and alter vascular smooth muscle cell (VSMC) function and growth. The aim of this study was to investigate the growth of aortic VSMCs from cirrhotic rats with or without the addition of angiotensin II and to determine whether angiotensin II binding was preserved in cirrhotic VSMCs. METHODS: Cirrhosis was induced by bile duct ligation. Cell growth was studied in cultured aortic VSMCs at passage levels between 4 and 16 by determining cell number and protein synthesis. RESULTS: Proliferation rates of cirrhotic VSMCs were lower than those of control VSMCs. The addition of angiotensin II to control VSMCs caused an increase in cell proliferation and protein synthesis. This increase was not observed in cirrhotic cells. There were more angiotensin II receptors in cirrhotic than in control VSMCs, but no significant changes in affinities were found. Angiotensin II-stimulated protein synthesis was dependent on protein kinase C activity and increased intracellular Ca2+ concentrations. CONCLUSIONS: This study shows abnormalities in growth characteristics and responsiveness to angiotensin II of cultured aortic VSMCs from rats with cirrhosis.     

Association of pulmonary artery aneurysm, right heart thromboses and antiphospholipid antibodies in Behcet''s disease

Five cases of Kingella kingae skeletal infections were diagnosed in children admitted to La Timone Hospital between 1992 and 1997. Patients were between 6 and 31 months old and presented with septic spondylodiskitis, calcaneus osteomyelitis, and hip-joint arthritis. All displayed either an upper respiratory tract infection or eczema during the month prior to their admission. Laboratory findings included an elevated leukocyte count and an elevated erythrocyte sedimentation rate. Standard radiography was unrevealing, but 99mTc bone scans and magnetic resonance imaging showed significant abnormalities. Isolation of Kingella kingae was achieved in all cases by culture of fluid aspirates using the Bactec blood culture system. This bacterium was sensitive to the most common antibiotics tested, and the outcome was favourable in all cases.