An algorithm to estimate the real time secondary infections in sub-urban bus travel: COVID-19 epidemic experience at Chennai Metropolitan city India.

Globalization, global climatic changes, and human behavior pose threats to highly pathogenic avian influenza (HPAI) virus spillover from animals to human. Current SARS-CoV2 transmission continues in several countries despite drastic reduction in COVID-19 cases following world-wide containment measures including RNA vaccines. China reimposed lockdown in November 2022 following the surge in commercial hubs. Urban population density and intracity travel in over-crowded public transport play crucial roles in early transition to an exponential phase of the epidemic in metro-cities. Based on the SARS-CoV2 transmission during the lockdown period in Chennai metro-city, we developed an algorithm that mimics a real-time scenario of passengers boarding and deboarding at each bus-stop on a trip of 36.1 km in 21G bus service in Chennai city to understand the pattern of secondary infections on a daily basis. The algorithm was simulated to estimate R0, and the COVID-19 secondary infections was estimated for each bus trip. Results showed that the R0 depended on the boarding and deboarding of the infected individuals at various bus stops. R0 varied from 0 to 1.04, each trip generated 5-9 secondary infections and four bus stops as potential locations for a higher transmission level. More than 80% of the working population in metro-cities depends on unorganized sectors, and separate mitigation strategies must be in place for successful epidemic containment. The developed algorithm has significant public health relevance and can be utilized to draw necessary containment plans in near future in the event of new COVID-19 wave or any other similar epidemic. Supplementary Information: The online version contains supplementary material available at 10.1007/s13337-022-00804-9.

Epidural blood patch for spontaneous intracranial hypotension (SIH): a report of two cases.

One of the latest diagnoses that need to be considered when evaluating patients with persistent headache is spontaneous (postural) intracranial hypotension (SIH). The diagnosis can be clinched by magnetic resonance imaging (MRI) findings of subdural collections, meningeal enhancement and tonsillar descent. Cerebrospinal fluid leak has been postulated as the cause, and both medical and surgical treatment options have been documented. The treatment of choice is, however, an epidural blood patch. Here we discuss two cases of SIH treated successfully with epidural blood patch.

A serine protease-associated lectin in the cytolytic system of blowfly (Chrysomya megacephala) larvae: Evidence and characterization.

Cytolytic activity against invading microorganisms is one of the innate forms of immunity in invertebrates. A serine protease-associated sialic acid-specific cytolytic lectin was purified using glutaraldehyde-fixed ox erythrocytes from the larval extract of blowfly (Chrysomya megacephala). The purified lectin lysed vertebrate erythrocytes with effective haemolysis of ox red blood cells (RBCs) in an isotonic medium. The degree of haemolytic (HL) activity of the purified cytolytic lectin depended on its concentration, pH, temperature, and calcium ions. It was sensitive to ethylenediaminetetraacetic acid. The native molecular mass of the C-type lectin was 260 ± 26 kDa, comprising four different polypeptide subunits of 75 kDa (pI ~8), 69 kDa (pI ~7.0), 61 kDa (pI ~5.3), and 55 kDa (pI ~4.6). The association between the C-type lectin and serine protease was confirmed by MALDI-TOF-MS analysis that revealed its homology in the same spectral peak as well as the proteases and phenylmethylsulphonyl fluoride inhibition of HL activity. Haemolysis inhibition by N-acetylneuraminic acid and other sugars revealed the properties of the lectin. The purified lectin distorted the integrity of ox RBCs and Paenalcaligenes hermetiae. This in vitro study documents the presence of a cytolytic system in blowfly (C. megacephala) larvae for the clearance of invading microbial pathogens in their feeding niche.

ß-Galactoside binding lectin from caddisfly larvae, Stenopsyche kodaikanalensis with selective modes of antibacterial activity: Purification and characterization.

Insects sustain the invading bacterial pathogens by inducing the production of lectin which participates in surveillance of non-self molecules. The antibacterial property of lectin is an inevitable aspect of innate immune system especially for the insects feeding the detritus organic matter. ß-galactoside binding lectin possessing antibacterial property was detected and purified from the hemolymph of larvae of caddisfly, Stenopsyche kodaikanalensis using affinity chromatography. The purified lectin exhibited highest hemagglutination titer value against buffalo erythrocytes and has affinity to lactose and fetuin which contains ß-galactoside linkages. It was found to be calcium independent, EDTA insensitive and heat labile. These reveal the characteristics features of S-Lac lectin. The molecular weight of lectin was 360 kDa with five distinct subunits such as 95, 90, 66, 62 and 47 kDa. The sequences acquired through MALDI-TOF-MS analysis shared homologies to the putative conserved region of leguminous lectin. Antibacterial studies were carried out with native soil bacterial isolates. It revealed that the lectin possessed the specific modes of action against bacteria that it can agglutinate the Bacillus subtilis and lyse the Bacillus flexus.

Purification and functional characterization of lectin with phenoloxidase activity from the hemolymph of cockroach, Periplaneta americana.

Lectins also identified as hemagglutinins are multivalent proteins and on account of their fine sugar-binding specificity play an important role in immune system of invertebrates. The present study was carried out on the hemolymph lectin of cockroach, Periplaneta americana with appropriate screening and purification to understand its molecular as well as functional nature. The lectin from the hemolymph was purified using ion-exchange chromatography. The approximate molecular weight of purified lectin was 340 kDa as determined by FPLC analysis. Rabbit erythrocytes were highly agglutinated with purified lectin from the hemolymph of P. americana. The hemagglutination activity (HA) of lectin was specifically inhibited by fucose. Glycoproteins also inhibited the HA activity of lectin. The amino acid sequences of the purified lectin revealed homology with amino acid sequences of allergen proteins from P. americana. Purified lectin showed the highest phenoloxidase activity against dopamine. The activators such as exogenous proteases and LPS from Escherichia coli and Salmonella minnesota significantly enhanced the PO activity of the purified lectin. Besides, the presence of copper and hemocyanin conserved domain in the purified lectin provided a new facet that insects belonging to the ancient clade such as cockroaches retained some traces of evolutionary resemblance in possessing lectin of ancient origin.

Direct compressive measurements of individual titanium dioxide nanotubes.

The mechanical compressive properties of individual thin-wall and thick-wall TiO(2) nanotubes were directly measured for the first time. Nanotubes with outside diameters of 75 and 110 nm and wall thicknesses of 5 and 15 nm, respectively, were axially compressed inside a 400 keV high-resolution transmission electron microscope (TEM) using a new fully integrated TEM-atomic force microscope (AFM) piezo-driven fixture for continuous recording of the force-displacement curves. Individual nanotubes were directly subjected to compressive loading. We found that the Young's modulus of titanium dioxide nanotubes depended on the diameter and wall thickness of the nanotube and is in the range of 23-44 GPa. The thin-wall nanotubes collapsed at approximately 1.0 to 1.2 microN during axial compression.

Immobilized cell reactors in mineralization of dicarboxylic acid solid waste.

Dicarboxylic acid solid waste containing phthalic acid, malic acid, quinone, saturated and unsaturated dicarboxylic esters etc., are discharged in huge quantities during the crackdown of benzene over the catalyst vanadium at temperatures greater than 500 degrees C in a dicarboxylic acid manufacturing industry. Concern over the biological effects of these compounds underlines the necessity to treat this solid waste. The role of yeast Saccharomyces cerevisiae and anaerobic mixed bacterial cultures immobilized in activated carbon, in sequential two stage anoxic reactors, were investigated for the degradation of dicarboxylic acid solid waste (DASW). In the first stage, DASW was dissolved in water to yield a concentration of 0.5% w/v and was treated in yeast Saccharomyces cerevisiae immobilized reactor at an optimum residence time of 24 h. The yeast fermented samples were further treated in an upflow anaerobic reactor containing mixed culture immobilized in activated carbon at an Hydraulic Retention Time (HRT) of 0.2076 days at an hydraulic flow rate of 14.6x10(-3 )m(3)/day and Chemical Oxygen Demand (COD) loading rate of 4.3 kg/m(3)/day. The intermediates that were formed during the yeast fermentation and the anaerobic degradation of DASW were characterized by HPLC, proton NMR, C(13) NMR and mass spectrometry.

Construction of conjugated molecular structures on gold nanoparticles via the Sonogashira coupling reactions.

Functional, conjugated molecular structures have been fabricated on Au nanoparticles via the Sonogashira coupling reactions.