HBF4 Catalysed Nucleophilic Substitutions of Propargylic Alcohols

The activity of HBF4 (aqueous solution) as a catalyst in propargylation reactions is presented. Diverse types of nucleophiles were employed in order to form new C–O, C–N and C–C bonds in technical acetone and in air. Good to excellent yields and good chemoselectivities were obtained using low acid loading (typically 1 mol-%) under simple reaction conditions

The actin-myosin regulatory MRCK kinases: regulation, biological functions and associations with human cancer

The contractile actin-myosin cytoskeleton provides much of the force required for numerous cellular activities such as motility, adhesion, cytokinesis and changes in morphology. Key elements that respond to various signal pathways are the myosin II regulatory light chains (MLC), which participate in actin-myosin contraction by modulating the ATPase activity and consequent contractile force generation mediated by myosin heavy chain heads. Considerable effort has focussed on the role of MLC kinases, and yet the contributions of the myotonic dystrophy-related Cdc42-binding kinases (MRCK) proteins in MLC phosphorylation and cytoskeleton regulation have not been well characterized. In contrast to the closely related ROCK1 and ROCK2 kinases that are regulated by the RhoA and RhoC GTPases, there is relatively little information about the CDC42-regulated MRCKα, MRCKβ and MRCKγ members of the AGC (PKA, PKG and PKC) kinase family. As well as differences in upstream activation pathways, MRCK and ROCK kinases apparently differ in the way that they spatially regulate MLC phosphorylation, which ultimately affects their influence on the organization and dynamics of the actin-myosin cytoskeleton. In this review, we will summarize the MRCK protein structures, expression patterns, small molecule inhibitors, biological functions and associations with human diseases such as cancer

The disruption of proteostasis in neurodegenerative diseases

Cells count on surveillance systems to monitor and protect the cellular proteome which, besides being highly heterogeneous, is constantly being challenged by intrinsic and environmental factors. In this context, the proteostasis network (PN) is essential to achieve a stable and functional proteome. Disruption of the PN is associated with aging and can lead to and/or potentiate the occurrence of many neurodegenerative diseases (ND). This not only emphasizes the importance of the PN in health span and aging but also how its modulation can be a potential target for intervention and treatment of human diseases.info:eu-repo/semantics/publishedVersio

STUDY OF PRESSURE AND COMPOSITION EFFECT ON MULTICOMPONENT MEMBRANE SEPARATION INVOLVING HEAVY HYDROCARBON GAS PENTANE

This work study the performance and characterize polyimide hollow fiber membranes for the separation of CO2-CH- C5H12 at difference pressure and feed composition as well as the effect of heavy hydrocarbon gas C5H12 on membrane performance. In Malaysia, approximately 13 trillion ft³ of high CO2 natural gas field are uneconomical to be developed. Development of high CO2 gas fields requires prudent management of carbon dioxide capture, transportation, and storage to enable commercialization of these fields. Research conducted on CO2 separation using membrane is limited especially on multicomponent and involving heavy hydrocarbon gas. Scope of experimental study focus on pure gas, gas mixture with and without heavy hydrocarbon gas C5H12 as well as varies the feed pressure from 10 bar to 18 bar and CO2 feed composition from 10% to 90%. Research methodologies include fabrication of membrane module, membrane characterization using FTIR, FESEM, and performances testing with CO2SMU and GC. FTIR finding show that membrane matrix’s polar sites enhance the preferential interaction and solubility of CO2 gas molecules, resulting in higher CO2 permeates flow compare to CH4 & C5H12. Decrease in flux, permeance and CO2 relative permeance is observed in gas mixture feed especially with present of heavy hydrocarbon gas C5H12. C5H12. As feed pressure increase, driving force increase preferentially sorbed of CO2 gas increase CO2 flux significantly, while CH4 and C5H12 flux only increase marginally. Furthermore, membrane layer compaction and plasticization increase CO2 permeance and relative permeance. As CO2 feed composition increase, membrane plasticize more, increasing preferentially sorbed of CO2 gas at matrix’s polar sites, thus increasing CO2 flux and permeance while, CH4 and C5H12 flux and permeance remain constant. So, CO2 relative permeance increases. In the nutshell, polyimide hollow fiber membranes show promising performance for separation of CO2-CH- C5H12 and experimental findings can be used for Multicomponent Hollow Fiber Membrane Module Performance Prediction Program (HFM3P)

Prenatal exposures and exposomics of asthma

This review examines the causal investigation of preclinical development of childhood asthma using exposomic tools. We examine the current state of knowledge regarding early-life exposure to non-biogenic indoor air pollution and the developmental modulation of the immune system. We examine how metabolomics technologies could aid not only in the biomarker identification of a particular asthma phenotype, but also the mechanisms underlying the immunopathologic process. Within such a framework, we propose alternate components of exposomic investigation of asthma in which, the exposome represents a reiterative investigative process of targeted biomarker identification, validation through computational systems biology and physical sampling of environmental medi

Holographic Charged Fluid with Anomalous Current at Finite Cutoff Surface in Einstein-Maxwell Gravity

The holographic charged fluid with anomalous current in Einstein-Maxwell gravity has been generalized from the infinite boundary to the finite cutoff surface by using the gravity/fluid correspondence. After perturbing the boosted Reissner-Nordstrom (RN)-AdS black brane solution of the Einstein-Maxwell gravity with the Chern-Simons term, we obtain the first order perturbative gravitational and Maxwell solutions, and calculate the stress tensor and charged current of the dual fluid at finite cutoff surfaces which contains undetermined parameters after demanding regularity condition at the future horizon. We adopt the Dirichlet boundary condition and impose the Landau frame to fix these parameters, finally obtain the dependence of transport coefficients in the dual stress tensor and charged current on the arbitrary radical cutoff $r_c$. We find that the dual fluid is not conformal, but it has vanishing bulk viscosity, and the shear viscosity to entropy density ratio is universally $1/4\pi$. Other transport coefficients of the dual current turns out to be cutoff-dependent. In particular, the chiral vortical conductivity expressed in terms of thermodynamic quantities takes the same form as that of the dual fluid at the asymptotic AdS boundary, and the chiral magnetic conductivity receives a cutoff-dependent correction which vanishes at the infinite boundary.Comment: 19 pages, v2: references added, v3: typos corrected, v5: typos corrected, version accepted for publication in JHE

Synthesis of thiourea chitosan and thiourea chitosan metal complexes and antibactarial activity

Chitosan and its derivatives are becoming increasingly important natural polymers because of their unique combination of properties like biodegradability, biocompatibility and bioactivity, in addition to attractive physical and mechanical properties. Here we wish to report the synthesis and characterization of thiourea chitosan and its metal-complex. Thiourea chitosan was prepared by the reaction of chitosan with ammonium thiocyanate in ethanol. Its metal complex was prepared by dissolving thiourea chitosan in 1% CH3COOH solution follow by adding metal salt solution.  Antimicrobial activities of the complexs were evaluated against three species of bacteria. These complexs had an effect on study bacteria, which minimum inhibition concentrate (MIC) values against bacteria were 2 times lower than those of Thiourea-chitosan; the complex had higher antibacterial activity on Staphylococcus aureus than E. coli and Pseudomonas aeruginosa

Silicon Atomic Quantum Dots Enable Beyond-CMOS Electronics

We review our recent efforts in building atom-scale quantum-dot cellular automata circuits on a silicon surface. Our building block consists of silicon dangling bond on a H-Si(001) surface, which has been shown to act as a quantum dot. First the fabrication, experimental imaging, and charging character of the dangling bond are discussed. We then show how precise assemblies of such dots can be created to form artificial molecules. Such complex structures can be used as systems with custom optical properties, circuit elements for quantum-dot cellular automata, and quantum computing. Considerations on macro-to-atom connections are discussed.Comment: 28 pages, 19 figure

Plain language summary of the TOPAZ-1 study: Durvalumab and chemotherapy for advanced biliary tract cancer

WHAT IS THIS SUMMARY ABOUT?: This is a summary describing the results of a Phase III study called TOPAZ-1. The study looked at treatment with durvalumab (a type of immunotherapy) and chemotherapy to treat participants with advanced biliary tract cancer (BTC). Advanced BTC is usually diagnosed at late stages of disease, when it cannot be cured by surgery. This study included participants with advanced BTC who had not received previous treatment, or had their cancer come back at least 6 months after receiving treatment or surgery that aimed to cure their disease. Participants received treatment with durvalumab and chemotherapy or placebo and chemotherapy. The aim of this study was to find out if treatment with durvalumab and chemotherapy could increase the length of time that participants with advanced BTC lived, compared with placebo and chemotherapy. WHAT WERE THE RESULTS OF THE STUDY?: Participants who took durvalumab and chemotherapy had a 20% lower chance of experiencing death at any point in the study compared with participants who received placebo and chemotherapy. The side effects experienced by participants were similar across treatment groups, and less than 12% of participants in either treatment group had to stop treatment due to treatment-related side effects. WHAT DO THE RESULTS OF THE STUDY MEAN?: Overall, these results support durvalumab and chemotherapy as a new treatment option for people with advanced BTCs. Based on the results of this study, durvalumab is now approved for the treatment of adults with advanced BTCs in combination with chemotherapy by government organizations in Europe, the United States and several other countries