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1.
Topics in Catalysis - In this work, a simple thermal-catalytic system was used to valorize peanut shells (Arachis hypogaea), the residual biomass from the peanut industry. To accomplish this...  相似文献   
2.
The catalytic behavior of a Keggin type potassium dodecatungstocobaltate (II) salt supported on ZSM-5 zeolite for wet peroxide oxidation of 2-(methylthio)benzothiazole, as a model organic sulfide, was thoroughly studied. Microporous ZSM-5 zeolite was obtained by the hydrothermal crystallization method. The Keggin salt was incorporated in the MFI zeolite matrix by the wet impregnation method followed by calcination at 350 °C. Catalysts were further characterized by X ray diffraction, UV–Vis diffuse reflectance spectroscopy and scanning electron microscopy-EDAX techniques. Supported and bulk Keggin dodecatungstocobaltate (II) were compared with pure H-ZSM-5 zeolite as catalysts for the sulfide oxidation. When the reaction was not catalyzed, just a 9 mol% of sulfide conversion was obtained. Reaction parameters, such as nature of the solvent, hydrogen peroxide concentration, reaction time, catalyst mass, substrate initial concentration and reaction temperature, were evaluated to reach the optimum reaction conditions, considering substrate conversion and sulfoxide and sulfone selectivities. Catalyst stability in several oxidation cycles was also examined.  相似文献   
3.
Photoconduction and hologram recording in a Bi12SiO20single crystal are studied from both theoretical and experimental points of view in the case of short pulse excitations. An approach taking into account two kinds of acceptor centers explains the charge transport processes in the case of both pulsed and continuous illuminations. A nanosecond temporal resolution allows us to access a time domain that is not normally considered, and on this time scale, the electron migration velocity is governed by the intrinsic mobility, which we have estimated to he greater than 3.2 cm2/V . s. Using this value, our theoretical developments explain the fast beam coupling phenomenon that we have experimentally observed.  相似文献   
4.
Contaminated shellfish have been implicated in gastroenteritis outbreaks in different countries. As no regulation has been set up yet regarding viral contamination of food, very few data are available on the prevalence of contaminated products on the market. This study presents data obtained from oysters collected on the French market in one producing area over a 16 month period of time. Noroviruses were detected in 9% of samples with a seasonal impact and influence of climatic events. Contamination levels were low and, surprisingly, oysters sampled directly from the producer were found to have less contamination than oysters from supermarkets.  相似文献   
5.
Occupational exposures contribute to the morbidity and mortality of many diseases. However, occupational diseases continue to be underrecognized even though they are responsible for an estimated 860,000 illnesses and 60,300 deaths each year. Family physicians can play an important role in improving the recognition of occupational disease, preventing progressive illness and disability in their own patients, and contributing to the protection of other workers similarly exposed. This role can be maximized if physicians raise their level of suspicion for workplace disease, develop skills in taking occupational histories and establish routine access to occupational health resources.  相似文献   
6.
A new sulfide of vanadium and thallium TlV5S8 has been prepared. It has monoclinic symmetry with space group C2 and cell dimensions: a = 17.465 A?, b = 3.301 A?, c = 8.519 A? and β = 103.94°. The structure can be described as a 3D framework made up of infinite layers and double chains which consist of VS6 octahedra sharing faces and edges. Large rectangular tunnels host the thallium atoms. The compound shows metallic behavior.  相似文献   
7.
The aim of this study was to develop a technique for separating monocytic cells in suspension from peripheral blood to measure the intracellular penetration of three fluoroquinolones (ofloxacin, ciprofloxacin and sparfloxacin). Mononucleated cells were isolated from the blood on a density gradient with lymphoprep and purified by a specific technique of adhesion and disadhesion on fibronectin. The monocytes were obtained in suspension with 76.8% purity and 97.9% viability. This was a convenient form for measurement of intracellular accumulation by use of the velocity-centrifugation technique. Intra-monocytic penetration of ciprofloxacin, ofloxacin and sparfloxacin was measured at equilibrium after 30-min incubation in the presence of 16 microg mL(-1) antibiotic. The results revealed low intra-monocytic accumulation of ciprofloxacin (intracellular-extracellular = 1.76) and ofloxacin (intracellular-extracellular = 1.42). The penetration of sparfloxacin was significantly higher (intracellular-extracellular = 2.4). This study confirms the important differences between human immunocompetent cells in terms of their ability to concentrate quinolones. It also underlines the importance of monocyte-macrophage cellular differentiation as a determinant of antibiotic penetration.  相似文献   
8.
Applied Composite Materials - This article discusses techniques that aim at facilitating the identification of dissipative mechanisms activated in woven composites under cyclic loadings. The focus...  相似文献   
9.
TachoComb is a new, ready-to-use hemostatic agent consisting of a collagen sheet coated on one side with human fibrinogen, bovine thrombin, and bovine aprotinin. The product was used in 125 surgical operations (vascular, hepatic, urological and ENT) in which secondary hemostasis was required. It was placed over the cut surface or over the edges of the wound. The investigating surgeons expressed their opinion on the intra- and postoperative hemostatic efficacy, and routine laboratory tests were done postoperatively. TachoComb had good hemostatic efficacy in 67.2% of cases, and very good in 22.4%. No noteworthy systemic changes were observed. As an adjuvant to obtain complete hemostasis in surgery, TachoComb is effective, practical and quick to use, and is very well tolerated.  相似文献   
10.
OBJECTIVES: Intravenous immunoglobulins have been shown to be effective in the treatment of immunologically mediated thrombocytopenia. Several articles have been published on the positive effect of immunoglobulins in sepsis-related death. We retrospectively studied the effects of intravenous immunoglobulins used during septic shock thrombocytopenia over a 5-year period in a polyvalent intensive care unit. PATIENTS AND METHODS: Inclusion criteria were development of acute thrombocytopenia under 75 G/l during septic shock, excluding all cases of disseminated intravascular coagulation. Thirty-five patients were included in the study; 18 were given polyvalent intravenous immunoglobulins (group IgIV) and 17 were not (controls). The two groups were comparable for SAPS and APACHE II gravity scores at admission and at day 0 (first day of septic shock with platelet count under 75 G/l), age, sex, platelet count at admission, OSF score, type of referral unit, McCabe score, and the presence of 4 parameters which might affect platelet count hemofiltration, ARDS, surgery, Swan-Ganz catheter. RESULTS: Platelet counts increased on day 8 in the treatment group (63.5 G/l, range 25-453 versus 105.7 G/l, range 38-355; p = 0.0505). The number of days with thrombocytopenia was the same in both groups. Overall mortality was high (60%) but there was a difference between the two groups in favor of the treated group (74.7% versus 44.4%; p = 0.053). The number of red cell units (214 vs. 164) and plasma units (175 vs. 54) transfused was higher in the control group. Platelet transfusion was equivalent in the two groups. DISCUSSION: Although we were unable to demonstrate a significant difference in the effects of immunoglobulins on platelet level and mortality, the trend during this evaluation was comparable with that reported in the literature. For transfusion, and although the results were not significant, a notion of reduced risk was evident. Prospective trials are needed to confirm these observations.  相似文献   
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