Study of viscosity of mono-, di-, and trialkylamines

Viscosities of several mono-, di-, and trialkylamines have been measured in the temperature range 298 to 333 K. It is observed that viscosities are highly dependent on shape, size, and association through H-bond or through dipole. Following the transition state theory, energy, Gibbs free energy, and entropy of activation of viscous flow have been calculated. The values of expansion energy for these liquids have also been calculated using free volume theory, and subsequently amines have been classified as volume-restrained or energy-restrained liquids. The group contribution method of Van Velzen, Cardozo, and Langenkamp for estimating viscosity has been examined with the present and literature data, and the new group contribution increments N _i and B _i for amines have been evaluated.     

Human DDX3X Unwinds Japanese Encephalitis and Zika Viral 5′ Terminal Regions

Flavivirus genus includes many deadly viruses such as the Japanese encephalitis virus (JEV) and Zika virus (ZIKV). The 5′ terminal regions (TR) of flaviviruses interact with human proteins and such interactions are critical for viral replication. One of the human proteins identified to interact with the 5′ TR of JEV is the DEAD-box helicase, DDX3X. In this study, we in vitro transcribed the 5′ TR of JEV and demonstrated its direct interaction with recombinant DDX3X (K_d of 1.66 ± 0.21 µM) using microscale thermophoresis (MST). Due to the proposed structural similarities of 5′ and 3′ TRs of flaviviruses, we investigated if the ZIKV 5′ TR could also interact with human DDX3X. Our MST studies suggested that DDX3X recognizes ZIKV 5′ TR with a K_d of 7.05 ± 0.75 µM. Next, we performed helicase assays that suggested that the binding of DDX3X leads to the unwinding of JEV and ZIKV 5′ TRs. Overall, our data indicate, for the first time, that DDX3X can directly bind and unwind in vitro transcribed flaviviral TRs. In summary, our work indicates that DDX3X could be further explored as a therapeutic target to inhibit Flaviviral replication     

Molecular Docking Studies and Biological Evaluation of Berberine–Benzothiazole Derivatives as an Anti-Influenza Agent via Blocking of Neuraminidase

In this study, we have introduced newly synthesized substituted benzothiazole based berberine derivatives that have been analyzed for their in vitro and in silico biological properties. The activity towards various kinds of influenza virus strains by employing the cytopathic effect (CPE) and sulforhodamine B (SRB) assay. Several berberine–benzothiazole derivatives (BBDs), such as BBD1, BBD3, BBD4, BBD5, BBD7, and BBD11, demonstrated interesting anti-influenza virus activity on influenza A viruses (A/PR/8/34, A/Vic/3/75) and influenza B viral (B/Lee/40, and B/Maryland/1/59) strain, respectively. Furthermore, by testing neuraminidase activity (NA) with the neuraminidase assay kit, it was identified that BBD7 has potent neuraminidase activity. The molecular docking analysis further suggests that the BBD1–BBD14 compounds’ antiviral activity may be because of interaction with residues of NA, and the same as in oseltamivir.     

INVESTIGATION OF THE USE OF LASER-DOPPLER VELOCIMETRY IN TWO-PHASE BUBBLY FLOWS

Understanding the dynamic phenomena of viability loss of shear sensitive cells and bubble breakage and coalescence within airlift reactors requires knowledge of local, liquid-phase hydrodynamics. The laser-Doppler velocimeter (LDV) is a non-invasive instrument which may be used to obtain this information. Experimental procedures and software were developed to detect and measure Doppler bursts in two-phase flow in a split-cylinder airlift reactor. Off-line analysis of the data indicated a detection rate approximately one order of magnitude greater than that observed using an available commercial frequency tracker. Approximately 400 to 500 observations are needed for the ensemble mean to characterize the local mean velocity to within ±5% for a superficial gas velocity of 10.4 cm/s, the highest superficial gas velocity used in these studies. The limitations, prospects, and signal-processing options for LDV in this application are also discussed     

粉末橡胶

介绍了Adar自主研制的Aparene NBR胶粉的特性、加工方法。特别对其改性PVC和PF的优越性，分别用其鞋类、电气绝缘板、摩擦衬片等产品所体现出来的各项优异性能做出充分说明。其在橡胶工业上的应用以制作胶粘剂为例，阐述了使用胶粉可改革加工方法，摈弃密炼机，节省能源等诸多的优点。     

Synthesis and characterization of poly(keto-amines). 2. Self-polycondensation of 4-methyl-3-aminophenacyl chloride and 2-methyl-4-aminophenacyl chloride

Poly(keto-amines) such as poly(4-methyl-3-iminophenacyls) and poly(2-methyl-4-iminophenacyls) were prepared by self-polycondensation of 4-methyl-3-aminophenacyl chloride and 2-methyl-4-aminophenacyl chloride under different experimental conditions. All the polymer samples were insoluble in common organic solvents. They were characterized by elemental analysis, IR spectral studies, estimation of M?_n by non-aqueous conductometric titration and study of thermal properties by DTA. The properties of P4M3IP and P2M4IP were compared with those of poly(4-iminophenacyls).     

Grafting of methyl methacrylate onto guar gum by hydrogen peroxide initiation

Graft copolymerization of methyl methacrylate (MMA) onto guar gum (GG) in aqueous slurry has been carried out using hydrogen peroxide (H₂O₂) as initiator. The copolymers were characterized by infrared spectroscopy. The grafting parameters like percent grafting, grafting efficiency, percent add-on, and the grafting frequency were determined, and the effect of reaction time, concentration of initiator, and [GG]/[MMA] ratios on the grafting parameters have been discussed. The decrease in % add-on at increasing concentration of H₂O₂ indicated enhancement in the rate of homopolymerization of methyl methacrylate.     

Self-emulsifiable soybean oil phosphate ester polyols for low-VOC corrosion resistant coatings

A series of soybean oil phosphate ester polyols (SOPEP) was prepared by reaction of fully epoxidized soybean oil with phosphoric acid and simultanoeous hydrolysis in the presence of a polar solvent. The polyols were characterized by determination of acid value, oxirane number, hydroxyl value, molecular weight (GPC), and FTIR spectra. These polyols with varying amounts of acid phosphate groups could be self-emulsified to form aqueous dispersions after neutralization with organic base. These aqueous dispersion showed varying degrees of stability and their appearance ranged from opaque dispersions to translucent to clear solutions. Waterborne coating compositions were prepared using these aqueous dispersions as principal components and their thermally cured film properties were studied. it was found that by careful selection and formulation, SOPEPs can be successfully used for low-VOC waterborne coating formulations. SOPEPs with 3.5% phosphate ester content showed visibly superior corrosion resistance properties.     

Predicting elastic moduli of heterogeneous polymer compositions

A new method for predicting elastic moduli M of heterogeneous polymer compositions is proposed. It is based on a phenomenological adjustment between parallel and series models for upper and lower bound moduli M_U and M_L. Thus, where ?_H is the volume fraction of hard phase, ?_S is the volume fraction of soft phase, and n is the only adjustable parameter since the upper and lower bound moduli are given by and where M_H and M_S are the moduli of the pure hard and soft phases, respectively. Predicted values of M are in agreement with measured values in a number of systems which include polyblends and composite materials of fixed morphology. The significance of n is discussed relative to concentrations in the area of a phase transition for the polyblends or relative to phase morphology in the case of fixed morphology compositions. Interestingly, the relationship, by analogy, is in agreement with measured values of polyblend melt viscosities.     

Morphological, mechanical and gas-transport characteristics of crosslinked poly(propylene glycol): homopolymers, nanocomposites and blends

Linear polyethers possess unusually high CO₂ solubility and, hence, selectivity due to the presence of accessible ether linkages that can interact with the quadrupolar moment of CO₂ molecules. In this work, membranes derived from crosslinked poly(propylene glycol) diacrylate (PPGda) oligomers differing in molecular weight (M), as well as PPGda nanocomposites containing either an organically-modified montmorillonite clay or a methacrylate-terminated fumed silica are investigated and compared with highly CO₂-selective poly(ethylene glycol) diacrylate (PEGda) homopolymer and nanocomposite membranes previously reported. The rheological and permeation properties of PPGda depend sensitively on M, with the elastic modulus decreasing, but CO₂ permeability and CO₂/H₂ selectivity increasing, with increasing M. Incorporation of either nanofiller into PPGda enhances the elastic modulus and reduces the gas permeability in the resultant nanocomposites without strongly affecting CO₂/H₂ selectivity. Blending PPGda and PEGda prior to chemical crosslinking yields binary membranes that exhibit intermediate gas-transport properties accurately described by a linear rule of mixtures.