234 research outputs found
Predicting Insulation And Structural Response Of Foamed Concrete Panel
Konkrit ringan berbusa (LFC) dihasilkan daripada mortar atau campuran simen berserta gelembung udara yang dihasilkan daripada agen campuran tertentu. Penggunaan LFC sebagai bahan binaan menjadi prerogatif dalam industri pembinaan kerana ia memiliki banyak kelebihan seperti lebih ringan, kekuatan rendah dikawal dan sifat haba yang sangat baik.
Lightweight foamed concrete (LFC) is produced by mortar or cement paste in which air-voids are entrapped in the mortar by means of suitable foaming agent. Demand and usage of LFC as building material become privileged in construction industry due to many advantages such as lighter weight, controlled low strength and excellent thermal properties
A comparative evaluation of shear bond strength between feldspathic porcelain and lithium di silicate ceramic layered to a zirconia core? An in vitro study
The bond strength between the zirconia core and ceramic veneer is the weakest component in the layered structure. Delamination of veneering ceramic is reported as one of the most frequent problems associated with Veneered Zirconia restorations. The aim of this study is to compare the shear bond strength of lithium di silicate porcelain to that of feldspathic porcelain on a zirconia Substrate. Two groups (group A and B) of zirconia blocks with each group having 20 samples were fabricated according to Schmitz Schulmeyer method. Group A (n =20 ) samples were veneered with feldspathic veneering porcelain and Group B (n=20) samples were veneered with heat pressed lithium disilicate ceramic. The fabricated samples were then evaluated for shear bond strength in Universal Testing Machine. The values were then statistically analyzed using independent sample t-test. Results of the current study showed that mean shear bond strength of feldspathic porcelain 11.40±1.29 MPa is comparatively lower than the mean shear bond strength of the lithium disilicate group 18.81±1.76 MPa. The statistical analysis indicated that (p value<0.01) there is a statistically significant difference in the shear bond strength between the two groups. The heat pressed lithium disilicate veneering materials has a better shear bond strength compared to feldspathic veneering ceramic material when layered to a zirconia core and it can be used as a viable alternative material to feldspathic porcelain layering material in bilayered zirconia restorations
Rhenium(I)-based Double-heterostranded Helicates
Rhenium(I)-based supramolecular coordination complexes were obtained using Re2(CO)10, (2-hydroxyphenyl)benzimidazole-derived bis-chelating N?O donors and a benzimidazolyl-derived ditopic monodentate N-donor possessing Troger's base spacer in a one-pot approach
A Possible Novel Anti-Inflammatory Mechanism for the Pharmacological Prolyl Hydroxylase Inhibitor 3,4-Dihydroxybenzoate: Implications for Use as a Therapeutic for Parkinson's Disease
Parkinson's disease (PD) is an age-related neurodegenerative disorder characterized in part by the preferential loss of nigrostriatal dopaminergic neurons. Although the precise etiology of PD is unknown, accumulating evidence suggests that PD involves microglial activation that exerts neurotoxic effects through production of proinflammatory cytokines and increased oxidative and nitrosative stress. Thus, controlling microglial activation has been suggested as a therapeutic target for combating PD. Previously we demonstrated that pharmacological inhibition of a class of enzymes known as prolyl hydroxylases via 3,4-dihydroxybenzoate administration protected against MPTP-induced neurotoxicity, however the exact mechanisms involved were not elucidated. Here we show that this may be due to DHB's ability to inhibit microglial activation. DHB significantly attenuated LPS-mediated induction of nitric oxide synthase and pro-inflammatory cytokines in murine BV2 microglial cells in vitro in conjunction with reduced ROS production and activation of NFκB and MAPK pathways possibly due to up-regulation of HO-1 levels. HO-1 inhibition partially abrogates LPS-mediated NFκB activity and subsequent NO induction. In vivo, DHB pre-treatment suppresses microglial activation elicited by MPTP treatment. Our results suggest that DHB's neuroprotective properties could be due to its ability to dampen induction of microglial activation via induction of HO-1
TRANSIENT DYNAMIC BEHAVIOR OF TWO PHASE MAGNETO-ELECTRO-ELASTIC SENSORS BONDED TO ELASTIC RECTANGULAR PLATES
Ursolic acid inhibits colistin efflux and curtails colistin resistant Enterobacteriaceae
Abstract
Colistin resistance in Enterobacteriaceae especially Klebsiella pneumoniae and Escherichia coli is driving the evolution of pan drug resistant strains. Screening a library of 13 plant nutraceuticals led to the identification of acetyl shikonin and ursolic acid, which exhibited synergy with colistin against extremely drug resistant (XDR) clinical strains of E. coli (U3790) and K. pneumoniae (BC936). Ursolic acid caused a significant colistin MIC reversal of 16-fold in U3790 and 4-fold in BC936 strains. Ursolic acid also potentiated the bactericidal effect of colistin against both U3790 and BC936 by causing ~ 4 to 4.5 log fold decline in CFU of both clinical isolates in a time kill assay. At 2× minimum effective concentration, ursolic acid was non-toxic to zebrafish as evidenced by brain and liver enzyme profiles and by histopathology studies. In combination with colistin, ursolic acid reduced bacterial bioburden of U3790/BC936 by 1–1.58 log fold from the infected muscle tissue of zebrafish. Mechanistic explorations via studies on real time efflux, membrane potential and intracellular accumulation of dansyl chloride tagged colistin revealed that colistin efflux is inhibited by ursolic acid. In addition, ursolic acid also enhanced outer membrane permeability which probably facilitates colistin’s attack on outer and inner membranes. Our study shows that ursolic acid synergizes with colistin by inhibiting colistin efflux in Enterobacteriaceae that helps to curtail colistin resistant Enterobacteriaceae.https://deepblue.lib.umich.edu/bitstream/2027.42/148135/1/13568_2019_Article_750.pd
Comparative study on prophylactic antibiotic versus empirical antibiotic in prevention of surgical site infection
The main aim of the study was to comparative study of single dose prophylactic antibiotic versus empirical postoperative antibiotics in prevention of surgical site infection. The study was a prospective observational study conducted over a period of 8months. A total of 100 number of surgery cases were selected randomly, to groups of 50 each. The study group received a single dose of antibiotic preoperatively while the control group received 3 to 5 days of empirical antibiotic therapy. Data analysis and statistical analysis was done with the help of graph pad prism trial version software. Student t test was carried out for paired analysis to find P value. There was no significant association of surgical site infection, grades of infection, and other complications. The hospital stay of patients, cost to the patients, and number of antibiotics used in patients were significantly more. The single dose prophylactic antibiotics are better than empirical post operative therapy in reducing the hospital stay and hospital cost to patients. Since the complete eradication of surgical site infection is not possible, only the reduction in infection rate can be achieved to a minimal level.
Keywords: Prophylactic antibiotics, surgical site infection, surgical complications, post operative antibiotics
Thermal properties of foamed concrete with various densities and additives at ambient temperature
This paper will focus on experimental investigation to observe the effects of different densities and additives on the thermal properties of foamed concrete by means of Hot Disk Thermal Constant Analyzer, so as to obtain a few fundamental thermal properties for prediction of its fire resistance performance.For this study, samples of three different densities of 700kg/m 3 , 1000kg/m 3 and 1400kg/m 3 and various additives were investigated to study the effects of densities and additives on the thermal properties of foamed concrete. The additives used in this research were pulverized fuel ash (PFA), silica fume, palm oil fuel ash (POFA), wood ash, polypropylene fibre, steel fibre and coir fibre. It should be pointed out that the lowest density of foamed concrete (700kg/m 3) has provided best thermal insulation properties due to large amount of pores and high percentage of air entrapped because air is poorest conductor of heat than solid and liquid. Also, foamed concrete with coir fibre achieved lowest thermal conductivity because it possess high heat resistance due to its large percentage of hemicellulose and lignin and exhibited high heat capacity as well due to the formation of uniform pores and voids in foamed concrete
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