The lift force on a charged sphere that translates and rotates in an electrolyte

The distortion of the charge cloud around a uniformly charged, dielectric, rigid sphere that translates and rotates in an unbounded binary, symmetric electrolyte at zero Reynolds number is examined. The zeta potential of the particle ζ is assumed small relative to the thermal voltage scale. It is assumed that the equilibrium structure of the cloud is slightly distorted, which requires that the Péclet numbers characterizing distortion due to particle translation, , and rotation, , are small compared to unity. Here, a is radius of the particle; D is the ionic diffusion coefficient; and , where U and Ω are the rectilinear and angular velocities of the particle, respectively. Perturbation expansions for small and are employed to calculate the nonequilibrium structure of the cloud, whence the force and torque on the particle are determined. In particular, we predict that the sphere experiences a force orthogonal to its directions of translation and rotation. This “lift” force arises from the nonlinear distortion of the cloud under the combined actions of particle translation and rotation. The lift force is given by . Here, ε is the permittivity of the electrolyte; is the Debye length; and is a negative function that decreases in magnitude with increasing . The lift force implies that an unconstrained particle would follow a curved path; an electrokinetic analog of the inertial Magnus effect. Finally, the implication of the lift force on cross‐streamline migration of an electrophoretic particle in shear flow is discussed.     

Effectiveness of radiation processing in elimination of Campylobacter from poultry meat

Campylobacter, a common poultry intestine commensal, is a well known cause of human gastric illnesses across the globe. Consumption of contaminated poultry meat is a major cause of Campylobacter related infections. In the present study, radiation sensitivity of indigenous strains of C. jejuni and C. coli isolated from poultry was evaluated. The decimal reduction dose (D₁₀) values of different Campylobacter isolates at 0-4 °C in saline and blood broth were in the range of 0.120-0.210 kGy and 0.170-0.234 kGy, respectively. D₁₀ values in chicken meat homogenate for Campylobacter were in the range of 0.110-0.190 kGy. Chicken meat samples were inoculated with C. jejuni and exposed to gamma radiation to study the effectiveness of radiation treatment in elimination of Campylobacter. Radiation treatment with a dose of 1 kGy could achieve complete elimination of 10⁵ CFU of Campylobacter/g in poultry meat samples. No recovery of Campylobacter was observed, even after enrichment and selective plating in 1 kGy treated chicken meat samples stored at 4 °C up to 7 days. Present study shows that irradiation of poultry meat with 1 kGy can ensure safety of poultry meat.     

Deciphering the Role of Filamin B Calponin-Homology Domain in Causing the Larsen Syndrome,Boomerang Dysplasia,and Atelosteogenesis Type I Spectrum Disorders via a Computational Approach

Filamins (FLN) are a family of actin-binding proteins involved in regulating the cytoskeleton and signaling phenomenon by developing a network with F-actin and FLN-binding partners. The FLN family comprises three conserved isoforms in mammals: FLNA, FLNB, and FLNC. FLNB is a multidomain monomer protein with domains containing an actin-binding N-terminal domain (ABD 1–242), encompassing two calponin-homology domains (assigned CH1 and CH2). Primary variants in FLNB mostly occur in the domain (CH2) and surrounding the hinge-1 region. The four autosomal dominant disorders that are associated with FLNB variants are Larsen syndrome, atelosteogenesis type I (AOI), atelosteogenesis type III (AOIII), and boomerang dysplasia (BD). Despite the intense clustering of FLNB variants contributing to the LS-AO-BD disorders, the genotype-phenotype correlation is still enigmatic. In silico prediction tools and molecular dynamics simulation (MDS) approaches have offered the potential for variant classification and pathogenicity predictions. We retrieved 285 FLNB missense variants from the UniProt, ClinVar, and HGMD databases in the current study. Of these, five and 39 variants were located in the CH1 and CH2 domains, respectively. These variants were subjected to various pathogenicity and stability prediction tools, evolutionary and conservation analyses, and biophysical and physicochemical properties analyses. Molecular dynamics simulation (MDS) was performed on the three candidate variants in the CH2 domain (W148R, F161C, and L171R) that were predicted to be the most pathogenic. The MDS analysis results showed that these three variants are highly compact compared to the native protein, suggesting that they could affect the protein on the structural and functional levels. The computational approach demonstrates the differences between the FLNB mutants and the wild type in a structural and functional context. Our findings expand our knowledge on the genotype-phenotype correlation in FLNB-related LS-AO-BD disorders on the molecular level, which may pave the way for optimizing drug therapy by integrating precision medicine.     

Synthesis and Structural Proof of a Potent 5-Lipoxygenase Inhibitor

Abstract  

5-Lipoxygenase inhibitor 3-O-acetyl-9,11-dehydro-β-boswellic acid was detected in the extract of Boswellia serrata gum resulting from unstable 11-hydroxy precursor. It was reported more potent than other Boswellic acids in its inhibition of 5-Lipoxygenase. Here, we report the method of conversion of 3-acetoxy-β-boswellic acid to 3-O-acetyl-9,11-dehydro-β-boswellic acid, and the crystal structure of later. This compound crystallizes in orthorhombic space group P2₁2₁2₁ with cell parameters of a = 12.726(1) ?, b = 16.597(1) ?, c = 27.332(2) ?, α = β = γ = 90°, V = 5772.7(5) ?³, D _c = 1.143 Mg/m³, and Z = 8. The X-ray structure investigation indicates that the rings A, B, D and E are exhibit chair and the ring C adopts a distorted half chair conformation. The conformational difference of the two structures in the arrangement is due to crystal packing of 3-O-acetyl-9,11-dehydro-β-boswellic acid. The molecular packing is stabilized by C–H···O and O–H···O types of hydrogen bonding interactions.     

Silicon detector technology development in India for the participation in international experiments

A specific research and development program has been carried out by BARC in India to develop the technology for large area silicon strip detectors for application in nuclear and high energy physics experiments. These strip detectors will be used as pre-shower detector in the CMS experiment at LHC, CERN for π ⁰/λ rejection. The fabrication technology to produce silicon strip detectors with very good uniformity over a large area of ∼40 cm², low leakage currents of the order of 10 nA/cm² per strip and high breakdown voltage of >500 V has been developed by BARC. The production of detectors is already under way to deliver 1000 detector modules for the CMS and 90% production is completed. In this paper, research and development work carried out to develop the detector fabrication technology is briefly described. The performance of the silicon strip detectors produced in India is presented. The present status of the detector technology is discussed.      

Influence of substrate temperature on the properties of electron beam evaporated ZnSe films

ZnSe films were deposited on glass substrates keeping the substrate temperatures, at room temperature (RT), 75, 150 and 250 °C. The films have exhibited cubic structure oriented along the (111) direction. Both the crystallinity and the grain size increased with increasing deposition temperature. A very high value of absorption co‐efficient (10⁴ cm^‐1) is observed. The band gap values decrease from a value of 2.94 eV to 2.69 eV with increasing substrate temperature. The average refractive index value is in the range of 2.39 – 2.41 for the films deposited at different substrate temperatures. The conductivity values increases continuously with temperature. Laser Raman spectra showed peaks at 140.8 cm^‐1, 246.7 cm^‐1and 204.5 cm^‐1which are attributable to 2TA LO phonon and TO phonon respectively. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Gas-phase Raman spectra of hot bands of fundamentals and combinations associated with the torsional vibration of s-trans-1,3-butadiene and its deuterated isotopologues

The gas-phase Raman spectra of 1,3-butadiene and its 2,3-d₂, 1,1,4,4-d₄, and d₆ isotopologues have been recorded with high sensitivity and resolution of 0.7 cm⁻¹. Hot band series of fundamentals and combinations involving the ν₁₃ torsional vibration of the s-trans rotamer have been observed for each of the isotopologues. Modes studied were ν₁₀ (CH wag), ν₁₂ (CH₂ twist), ν₁₀ + ν₁₂, ν₁₅ (CH₂ wag) + ν₁₆ (CH₂ twist), and ν₂₃ (CH₂ rock) + ν₂₄ (CCC deformation). The spacings of the quantum states of the torsional contribution were found to decrease with additional excitation of this mode (ν₁₃) in the upper vibrational states except for the ν₂₃ + ν₂₄ combination state.     

Vibrational spectra, structure, and theoretical calculations of 2-fluoro- and 3-fluoropyridine

The infrared and Raman spectra of liquid and vapor-phase 2-fluoropyridine and 3-fluoropyridine have been recorded and assigned. Ab initio and DFT calculations were carried out to compute the molecular structures and to verify the vibrational assignments. The observed and calculated spectra agree extremely well. The ring bond distances of the fluoropyridines are very similar to those of pyridine except for a shortening of the C-N(F) bond in 2-fluoropyridine. The C-F bond stretching frequencies are similar to that in fluorobenzene reflecting the influence of the ring π bonding.