168 research outputs found

    Sustainable Use of Biomass Boiler Ash as a Reinforcement Filler for Polyamide 6 Composite

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    The use of biomass combustion ash as a reinforcing filler has taken the attention in recent years to reduce the overall production cost and increase the mechanical properties of plastics. This study evaluates the effect of biomass boilers ash (BBA) as a reinforcing filler on polyamide 6 composites (PA6). The chemical composition and thermal stability of BBA were analyzed by X-ray fluorescence (XRF), Thermogravimetric analysis (TGA), and Differential thermal analysis (DTA) thermographs. Test samples were prepared by varying the ash content (2.5%, 5%, 7.5%, and 10%), and also samples were prepared without adding ash as a control. Moreover, surface modification was carried out by using N-2 (Aminoethyl) 3-aminopropyl triethoxy diamino-silane as a possible coupling agent for BBA  and it was tested by varying the coupling agent concentration (0.5%, 1%, and 2%) by dry process and the samples were prepared by extrusion and injection molding processes. Comparative analysis of the degree of crystallinity, mechanical properties including tensile, flexural, and thermal properties were tested. The highest degree of crystallinity was obtained with 7.5% BBA-filled composites. The addition of 2% surface-modified BBA (SBBA) filled composites (PA6 / 10% Ash 2% CA) showed an increase of tensile strength and elongation at break than the 10% unmodified BBA (UBBA) (PA6/ 10% Ash) filled composites. Stress at peak and bending modulus values in the flexural test data were increased up to 10%. But it was significantly reduced with the increasing of modifying agent concentration due to the increment of stiffness of the composite

    Investigation of itch in Parkinson disease

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    Introduction: Sensory abnormalities (eg, pain) are common in Parkinson disease (PD) with a negative impact on quality of life. As itch is less studied in PD, and pain and itch partially share sensory pathways, we designed this study to identify the occurrence and pattern of spontaneous itch, and responsiveness to a surrogate itch model in PD. Methods: The study protocol was approved (N-20180079) and PD patients and their best matched controls were recruited. A questionnaire was used to collect general information on itch. Sensory alterations were determined by subjective ratings and mechanical sensitivity threshold before and after a standard histamine-dependent itch model on forearms. Itch and pain intensities were rated on visual and numerical rating scales, respectively. Dispersion of itch was drawn on arm charts. Presence and area of alloknesis and hyperknesis were determined. Group comparisons were performed in SPSS with a significant level of 0.05. Descriptive statistic was used for questionnaire’s analysis. Results:Patients(n=20;68.10±7.91y,F/Mratio:8/12)andcontrols(n=20;67.35±7.65y,F/Mratio:8/12)wereexamined.PD patients rated less physical and emotional descriptors, except for the stinging (P = 0.028). No difference was found between the groups in histamine-provoked itch intensity (P = 0.799) or the itchy area. A significantly larger area of hyperknesis was found in PD (P = 0.011), but not for the area of alloknesis (P = 0.221). Sex-related responses yielded only a tendency toward higher responses in female patients. Discussion:PDdoesnotseemtoinfluenceperceptionofitch,neitherspontaneousnorevokeditch,exceptforhyperknesisarea,which was found significantly larger in PD patients following the application of histamine. This finding proposes a potential alteration in central processing of itch that needs further investigation and whether and how it is affected by, for example, PD pathogenesis

    An Amoeboid Olivine Aggregate in LEW 85300

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    Amoeboid Olivine aggregates (AOAs) are irregularly shaped objects commonly observed in carbonaceous chondrites. Because they are composed of fine-grained olivine and Ca-Al-rich minerals, they are sensitive indicators for nebular process and parent body alteration of their parent bodies. Recently an AOA was found in a carbonaceous clast in polymict eucrite LEW 85300. The bulk major element composition of the clast matrix in LEW 85300 suggests a relation to CM, CO and CV chondrites, whereas bulk clast trace and major element compositions do not match any carbonaceous chondrite, suggesting they have a unique origin. Here we characterize the mineralogy of AOA in LEW 85300 and discuss the origin of the carbonaceous clasts. Results and Discussion: The AOA is located in an impact melt vein. Half of the aggregate shows recrystallization textures (euhedral pyroxene and molten metal/FeS) due to impact melting, but the remaining part preserves the original texture. The AOA is composed of olivine, FeS and Mg,Al-phyllosilicate. Individual olivine grains measure 1-8 microns, with Fe-rich rims, probably due to impact heating. Olivines in the AOA are highly forsteritic (Fo95-99), indicating that the AOA escaped thermal metamorphism [4]. Although no LIME (Low-Fe, Mn-Enriched) olivine is observed, forsterite composition and the coexistence of Mg,Al-phyllosilicate suggest that the AOA is similar to those in the Bali-type oxidized CV (CVoxB) and CR chondrites. However, it should be noted that fayalitic olivine, which commonly occurs in CVoxB AOA, is not observed in this AOA. Also, the smaller grain size (<8 microns) of olivine suggests they may be related to CM or CO chondrites. Therefore, we cannot exclude the possibility that the AOA originated from a unique carbonaceous chondrite

    Use of sonic tomography to detect and quantify wood decay in living trees.

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    Premise of the studyField methodology and image analysis protocols using acoustic tomography were developed and evaluated as a tool to estimate the amount of internal decay and damage of living trees, with special attention to tropical rainforest trees with irregular trunk shapes.Methods and resultsLiving trunks of a diversity of tree species in tropical rainforests in the Republic of Panama were scanned using an Argus Electronic PiCUS 3 Sonic Tomograph and evaluated for the amount and patterns of internal decay. A protocol using ImageJ analysis software was used to quantify the proportions of intact and compromised wood. The protocols provide replicable estimates of internal decay and cavities for trees of varying shapes, wood density, and bark thickness.ConclusionsSonic tomography, coupled with image analysis, provides an efficient, noninvasive approach to evaluate decay patterns and structural integrity of even irregularly shaped living trees

    Removal of Hepatitis C Virus-Infected Cells by a Zymogenized Bacterial Toxin

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    Hepatitis C virus (HCV) infection is a major cause of chronic liver disease and has become a global health threat. No HCV vaccine is currently available and treatment with antiviral therapy is associated with adverse side effects. Moreover, there is no preventive therapy for recurrent hepatitis C post liver transplantation. The NS3 serine protease is necessary for HCV replication and represents a prime target for developing anti HCV therapies. Recently we described a therapeutic approach for eradication of HCV infected cells that is based on protein delivery of two NS3 protease-activatable recombinant toxins we named “zymoxins”. These toxins were inactivated by fusion to rationally designed inhibitory peptides via NS3-cleavable linkers. Once delivered to cells where NS3 protease is present, the inhibitory peptide is removed resulting in re-activation of cytotoxic activity. The zymoxins we described suffered from two limitations: they required high levels of protease for activation and had basal activities in the un-activated form that resulted in a narrow potential therapeutic window. Here, we present a solution that overcame the major limitations of the “first generation zymoxins” by converting MazF ribonuclease, the toxic component of the E. coli chromosomal MazEF toxin-antitoxin system, into an NS3-activated zymoxin that is introduced to cells by means of gene delivery. We constructed an expression cassette that encodes for a single polypeptide that incorporates both the toxin and a fragment of its potent natural antidote, MazE, linked via an NS3-cleavable linker. While covalently paired to its inhibitor, the ribonuclease is well tolerated when expressed in naïve, healthy cells. In contrast, activating proteolysis that is induced by even low levels of NS3, results in an eradication of NS3 expressing model cells and HCV infected cells. Zymoxins may thus become a valuable tool in eradicating cells infected by intracellular pathogens that express intracellular proteases
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