Enhanced microwave absorption behavior of polyaniline-CNT/polystyrene blend in 12.4–18.0 GHz range

Blends of polystyrene with polyaniline (PANI) coated multiwalled carbon nanotubes (MWCNTs) were designed which inherit dielectric and magnetic attributes from PANI and MWCNT respectively. The high resolution transmission electron microscopy image shows the PANI coating over MWCNT containing entrapped Fe catalyst. These blends show absorption dominated total shielding effectiveness (SE_T) of ?45.7 dB (>99.99% attenuation) in the 12.4–18.0 GHz range, suggesting their utility for making efficient microwave absorbers. The enhanced SE_T was ascribed to optimization of conductivity, skin-depth, complex permittivity and permeability. A good agreement between theoretical and experimental shielding measurements was also observed.     

Design and fabrication of low cost solar water heaters

We designed two types of very low cost solar water heaters which do not need a water supply connection. The first one consisted of two plastic bowls, one inside the other with 5 cm thickness of insulation in between. A transparent plastic cover was tied around the smaller vessel. It was found that water placed inside the smaller vessel had its temperature raised by 18°C from the ambient temperature within four hours when the average insolation was about 600 kWh/m². The second one consisted of two earthen vessels in place of plastic bowls. The water temperature rise was 20°C under the same radiation. If either of the heaters was covered with cotton-wool insulation in the afternoon, the temperature remains 13°C above the ambient early next morning. The cost of the material was around US$ 4.50 for the plastic bowl heater while this is around US$ 3.50 for the earthen vessel water heater.     

Phenotypic and genotypic characterization of human and nonhuman Escherichia coli

Estuarine waters receive fecal pollution from a variety of sources, including humans and wildlife. Escherichia coli is one of several fecal coliform bacteria that inhabit the intestines of many warm-blooded animals that sometimes contaminate water. Its presence does not specifically implicate human fecal input, therefore it is necessary to differentiate contamination sources to accurately assess health risks. E. coli were isolated from human sources (HS) and nonhuman sources (NHS) in the Apalachicola National Estuarine Research Reserve and analyzed for fatty acid methyl ester (FAME), O-serogroup, and pulsed-field gel electrophoresis (PFGE) profiles. For FAME and PFGE analyses, there was no relationship between profile and isolate source. Human source PFGE profiles were less diverse than NHS isolates, and conversely for FAME. In contrast, O-serogrouping showed less diversity for HS vs. NHS isolates, and the predominant HS O-serogroups differed significantly (P < 0.01) from those of NHS isolates.     

Synthesis and characterization of new polybenzoxazines from renewable resources for bio‐composite applications

Renewable natural resources such as eugenol, furfurylamine, stearylamine, and jute fiber were used to prepare polybenzoxazine composites. The purity of eugenol which is extracted from clove was confirmed by gas chromatography. FTIR, ¹H, and ¹³C NMR spectroscopic analysis were used to determine the structure of eugenol and the benzoxazine monomers namely 6‐allyl‐3‐furfuryl‐8‐methoxy‐3,4‐dihydro‐2H‐1,3‐benzoxazine (EF‐Bz) and 6‐allyl‐3‐octadecyl‐8‐methoxy‐3,4 dihydro‐2H‐1,3‐benzoxazine (ES‐Bz) synthesized from it. The curing analysis from differential scanning calorimetric analysis shows that the onset of curing is shifted to lower temperature (161°C) for EF‐Bz, when compared with ES‐Bz (174°C). The thermal stability analyzed from thermogravimetric analysis shows that the polybenzoxazine EF‐Pbz has higher thermal stability (T_5% = 361°C) with that of ES‐Pbz (T_5% = 313°C). The storage modulus, tensile, and flexural strength of the EF‐Bz/Jute fiber composite show high value when compared with ES‐Bz/Jute fiber composites. POLYM. COMPOS., 37:1821–1829, 2016. © 2014 Society of Plastics Engineers     

Synthesis and characterization of processable polyaniline doped with novel dopant NaSIPA

Aniline has been polymerized in the presence of a novel dopant sodio‐5‐sulfo‐isophthallic acid (NaSIPA), via the chemical oxidative polymerization route. The thermal stability and processability of polyaniline prepared by indirect method (PD1) have been improved significantly (290°C) as compared to polyaniline doped with conventional inorganic dopants like HCl or H₂SO₄, without much loss of electronic conductivity (5.07 S/cm in PD1). This suggests its use for melt blending with engineering thermoplastics. However, polyaniline prepared by direct method (PD2) can be melt‐blended only with conventional thermoplastics like polyethylene, polypropylene, polystyrene, etc. Low‐temperature studies reveal the 1‐D variable range hopping as a conduction mechanism for direct polymer (PD2), with parameters T_o and σ_o as 4112 K and 15.1 S/cm, respectively. However, for indirectly doped polymer (PD1) Arrhenius‐type model, having parameters |(E_F ? E_C)| and σ_C as 0.04 eV and 28.4 S/cm, respectively, it suited well. The coherence length as found from XRD data was around 28.8 nm for PD1 and 25.2 nm for PD2. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci 2008     

Synthesis and characterizations of nano-sized Ni(OH)2 and Ni(OH)2/poly(vinyl alcohol) nano composite

Nano-sized Ni(OH)₂ was synthesized by a co-precipitation method. Peaks between 500 and 750 cm⁻¹ in Fourier transform infrared spectroscopy (FTIR) confirmed the presence of metal hydroxide stretching. Thermo gravimetric analysis inferred that 69 wt% residue remained above 750 °C. High-resolution transmission electron microscopy analysis of Ni(OH)₂ revealed its size ranged from 80 to 110 nm with smooth morphology. Scanning electron microscopy inferred that pure Ni(OH)₂ has nano rod-like morphology and higher weight percentage of aniline-intercalated Ni(OH)₂ has agglomerated structure. UV–Vis spectrum detected the presence of Ni²⁺ ions at 210 nm and the existence of amino group in the basal spacing of Ni(OH)₂ was not clearly appeared in the spectrum. Photoluminescence (PL) inferred that aniline-intercalated Ni(OH)₂ showed higher PL intensity than the pristine poly(vinyl alcohol) its and nano composite.     

A multi-objective framework for the design of vacuum sealed molding process

This paper provides a framework for process design to achieve simultaneous improvement of the multiple features of the product. The methodology provides a way to integrate process parameters with the product features. Many of the features may be conflicting in nature, and thus may limit the use of a particular setting of design parameter of the process to produce the quality product. In this paper we discuss how to resolve the conflicting objectives of the process design problem. A case study for the design of vacuum-sealed molding process using the proposed methodology is included.     

Mutation in the CX3C Motif of G Protein Disrupts Its Interaction with Heparan Sulfate: A Calorimetric,Spectroscopic, and Molecular Docking Study

Respiratory syncytial virus (RSV) is the leading cause of lower respiratory tract infection in children and infants. To date, there is no effective vaccine available against RSV. Heparan sulfate is a type of glycosaminoglycan that aids in the attachment of the RSV to the host cell membrane via the G protein. In the present study, the effect of amino acid substitution on the structure and stability of the ectodomain G protein was studied. Further, it was investigated whether mutation (K117A) in the CX3C motif of G protein alters the binding with heparan sulfate. The point mutation significantly affects the conformational stability of the G protein. The mutant protein showed a low binding affinity with heparan sulfate as compared to the wild-type G protein, as determined by fluorescence quenching, isothermal titration calorimetry (ITC), and molecular docking studies. The low binding affinity and decreased stability suggested that this mutation may play an important role in prevention of attachment of virion to the host cell receptors. Collectively, this investigation suggests that mutation in the CX3C motif of G protein may likely improve the efficacy and safety of the RSV vaccine.     

Inhibitory Response to CK II Inhibitor Silmitasertib and CDKs Inhibitor Dinaciclib Is Related to Genetic Differences in Pancreatic Ductal Adenocarcinoma Cell Lines

Casein kinase II (CK2) and cyclin-dependent kinases (CDKs) frequently interact within multiple pathways in pancreatic ductal adenocarcinoma (PDAC). Application of CK2- and CDK-inhibitors have been considered as a therapeutic option, but are currently not part of routine chemotherapy regimens. We investigated ten PDAC cell lines exposed to increasing concentrations of silmitasertib and dinaciclib. Cell proliferation, metabolic activity, biomass, and apoptosis/necrosis were evaluated, and bioinformatic clustering was used to classify cell lines into sensitive groups based on their response to inhibitors. Furthermore, whole exome sequencing (WES) and RNA sequencing (RNA-Seq) was conducted to assess recurrent mutations and the expression profile of inhibitor targets and genes frequently mutated in PDAC, respectively. Dinaciclib and silmitasertib demonstrated pronounced and limited cell line specific effects in cell death induction, respectively. WES revealed no genomic variants causing changes in the primary structure of the corresponding inhibitor target proteins. RNA-Seq demonstrated that the expression of all inhibitor target genes was higher in the PDAC cell lines compared to non-neoplastic pancreatic tissue. The observed differences in PDAC cell line sensitivity to silmitasertib or dinaciclib did not depend on target gene expression or the identified gene variants. For the PDAC hotspot genes kirsten rat sarcoma virus (KRAS) and tumor protein p53 (TP53), three and eight variants were identified, respectively. In conclusion, both inhibitors demonstrated in vitro efficacy on the PDAC cell lines. However, aberrations and expression of inhibitor target genes did not appear to affect the efficacy of the corresponding inhibitors. In addition, specific aberrations in TP53 and KRAS affected the efficacy of both inhibitors.