Nano-Silica for Enhanced Greener Concrete

Colloidal nano-silica was added to normal and fly ash concretes with different rates to examine the its effect on different concrete performance aspects. The main objectives of the study is to determine the effect of adding nano-silica on: • The rate hydration and the reactivity of cement and pozzolans. • The mechanical properties and strength gain rate (especially for fly ash concrete). • Durability. • Microstructure and Porosity

Fluid Film Bearing Fundamentals And Failure Analysis.

Tutorialpg. 161-186Fluid film bearing technology is presented in this tutorial as it applies to turbomachinery equipment. The focus here is on the practical aspects of fluid film journal bearings, as opposed to theoretical analysis. Failure modes and the mechanisms leading to these failures will be discussed, along with techniques used to identify and cure them. The influence of different bearing configurations on the dynamics of rotor bearing systems will also be discussed

The Role of Protein Tyrosine Phosphatase (PTP)-1B in Cardiovascular Disease and Its Interplay with Insulin Resistance.

Endothelial dysfunction is a key feature of cardiovascular disorders associated with obesity and diabetes. Several studies identified protein tyrosine phosphatase (PTP)-1B, a member of the PTP superfamily, as a major negative regulator for insulin receptor signaling and a novel molecular player in endothelial dysfunction and cardiovascular disease. Unlike other anti-diabetic approaches, genetic deletion or pharmacological inhibition of PTP1B was found to improve glucose homeostasis and insulin signaling without causing lipid buildup in the liver, which represents an advantage over existing therapies. Furthermore, PTP1B was reported to contribute to cardiovascular disturbances, at various molecular levels, which places this enzyme as a unique single therapeutic target for both diabetes and cardiovascular disorders. Synthesizing selective small molecule inhibitors for PTP1B is faced with multiple challenges linked to its similarity of sequence with other PTPs; however, overcoming these challenges would pave the way for novel approaches to treat diabetes and its concurrent cardiovascular complications. In this review article, we summarized the major roles of PTP1B in cardiovascular disease with special emphasis on endothelial dysfunction and its interplay with insulin resistance. Furthermore, we discussed some of the major challenges hindering the synthesis of selective inhibitors for PTP1B

In-vitro application of a qatari burkholderia cepacia strain (QBC03) in the biocontrol of mycotoxigenic fungi and in the reduction of ochratoxin a biosynthesis by aspergillus carbonarius

Mycotoxins are secondary metabolites produced by certain filamentous fungi, causing human and animal health issues upon the ingestion of contaminated food and feed. Among the safest approaches to the control of mycotoxigenic fungi and mycotoxin detoxification is the application of microbial biocontrol agents. Burkholderia cepacia is known for producing metabolites active against a broad number of pathogenic fungi. In this study, the antifungal potential of a Qatari strain of Burkholderia cepacia (QBC03) was explored. QBC03 exhibited antifungal activity against a wide range of mycotoxigenic, as well as phytopathogenic, fungal genera and species. The QBC03 culture supernatant significantly inhibited the growth of Aspergillus carbonarius, Fusarium culmorum and Penicillium verrucosum in PDA medium, as well as A. carbonarius and P. verrucosum biomass in PDB medium. The QBC03 culture supernatant was found to dramatically reduce the synthesis of ochratoxin A (OTA) by A. carbonarius, in addition to inducing mycelia malformation. The antifungal activity of QBC03’s culture extract was retained following thermal treatment at 100 °C for 30 min. The findings of the present study advocate that QBC03 is a suitable biocontrol agent against toxigenic fungi, due to the inhibitory activity of its thermostable metabolites. View Full-TextFunding: Qatar National Research Fund (a member of Qatar Foundation) under National Priorities Research Program (NPRP) grant #NPRP8-392-4-003.Scopu

Hauliers’ perceptions and attitudes towards farm animal welfare could influence the operational and logistics practices in sheep transport

survey of Mexico-based sheep hauliers was conducted in order to investigate perceptions and attitudes toward farm animal welfare (FAW) and their influence on operational and logistic practices (OLPs) in sheep transportation. The statistical analysis consisted in the application of 2-factor analyses (OLP and animal welfare attitudes), additionally a cluster analysis; the latter allowed a segmentation of hauliers according to their attitudes and OLP. The factor analysis gave 3 OLP factors: logistic issues, economic losses, and welfare losses. In the case of factor analyses about animal welfare attitudes, we obtained 4 factors: training and regulations, animal needs, welfare improvement, and sensibility. The cluster analysis of this study showed the existence of 3 haulier profiles; these were “efficient and concerned,” “efficient and not concerned,” and “not efficient and concerned.” Our results showed that hauliers’ perceptions had a clear influence on the performance of their operative and logistic activities during the sheep transportation. This study highlights the individual hauliers’ risk factors which can be considered to improve not only animal welfare but also indicates the need to consider the transportation as a whole because of potential factor combinations and confusions. The attitudes of sheep hauliers toward FAWare a strategic component that requires being considered when hauliers are trained. If it can be shown that modifying hauliers’ attitudes leads to improved OLP, then there is an opportunity to develop specific training programs to modify certain haulier’s animal welfare attitudes, with a subsequent improvement of sheep welfar

Structure−Function Correlation of Chloroquine and Analogues as Transgene Expression Enhancers in Nonviral Gene Delivery

To understand how chloroquine (CQ) enhances transgene expression in polycation-based, nonviral gene delivery systems, a number of CQ analogues with variations in the aliphatic amino side chain or in the aromatic ring are synthesized and investigated. Our studies indicate that the aliphatic amino moiety of CQ is essential to provide increased gene expression. Further, the enhancements are more dramatically affected by changes to the aromatic ring and are positively correlated to the strength of intercalation between DNA and the CQ analogues. Quinacrine (QC), a CQ analogue with a fused acridinyl structure that can strongly intercalate DNA, enhances transfection similarly to CQ at a concentration 10 times lower, while N^4-(4-pyridinyl)-N^1,N^1-diethyl-1,4-pentanediamine (CP), a CQ analogue that has a weakly intercalating pyridinyl ring, shows no effect on gene expression. Subtle change on the 7-substituent of the chloroquine aromatic structure can also greatly affect the ability of the CQ analogues to enhance transgene expression. Transfection in the presence of N^4-(7-trifluoromethyl-4-quinolinyl)-N^1,N^1-diethyl-1,4-pentanediamin e (CQ7a) shows expression efficiency 10 times higher than in the presence of CQ at same concentration, while transfection in the presence of N^4-(4-quinolinyl)-N^1,N^1-diethyl-1,4-pentanediamine (CQ7b) does not reveal any enhancing effects on expression. Through a number of comparative studies with CQ and its analogues, we conclude that there are at least three mechanistic features of CQ that lead to the enhancement in gene expression:  (i) pH buffering in endocytic vesicles, (ii) displacement of polycations from the nucleic acids in polyplexes, and (iii) alteration of the biophysical properties of the released nucleic acid