Microplastics in packaged water, community stored water, groundwater, and surface water in rivers of Tamil Nadu after the COVID-19 pandemic outbreak.

The increased load of plastic in waste streams after the COVID-19 pandemic outbreak has increased the possibility of microplastics (MPs) contamination channelling through the rivers and infiltrating the aquatic ecosystems. MPs in packaged water, community-stored water, groundwater, and surface water of Kaveri River (KR), Thamirabarani River (TR), Adyar River (AR), and Cooum River (CR) in Tamil Nadu were therefore investigated about 2 years after the COVID-19 pandemic outbreak. Using µFTIR and µRaman spectroscopy, polyamide, polypropylene, polyethylene, ethylene vinyl alcohol copolymer resin, and polyvinyl chloride were identified as the primary polymer types. The average number of MPs was 2.15 ± 1.9 MP/L, 1.1 ± 0.99 MP/L, 5.25 ± 1.15 MP/L, and 4 ± 2.65 MP/L in KR, TR, AR, and CR, respectively, and 1.75 ± 1.26 MP/L in groundwater, and 2.33 ± 1.52 MP/L in community stored water. Only LDPE was detected in recycled plastic-made drinking water bottles. More than 50% of MPs were found to be of size less than 1 mm, with fibrous MPs being the prevalent type, and a notable prevalence of blue-coloured microplastics in all the sample types. The Pollution Load Index (PLI) was >1 in all the rivers. Toxicity rating based on the polymer risk index (PORI) categorized AR and TR at medium risk (category II), compared to KR and CR at considerable risk (category III). Overall pollution risk index (PRI) followed a decreasing trend with CR > AR > KR > TR of considerable to low-risk category. Ecological risk assessment indicates a negligible risk to freshwater biota, except for four sites in the middle and lower stretches of Adyar River (AR - 2, AR - 4) and upper and lower stretches of Cooum River (CR - 1, CR - 3), located adjacent to direct sewer outlets, and one location in the lower stretch of Kaveri River (KR - 9), known for fishing and tourist activities.

Automated Recognition of Cancer Tissues through Deep Learning Framework from the Photoacoustic Specimen.

The fast advancement of biomedical research technology has expanded and enhanced the spectrum of diagnostic instruments. Various research groups have found optical imaging, ultrasonic imaging, and magnetic resonance imaging to create multifunctional devices that are critical for biomedical activities. Multispectral photoacoustic imaging that integrates the ideas of optical and ultrasonic technologies is one of the most essential instruments. At the same time, early cancer identification is becoming increasingly important in order to minimize fatality. Deep learning (DL) techniques have recently advanced to the point where they can be used to diagnose and classify cancer using biological images. This paper describes a hybrid optimization method that combines in-depth transfer learning-based cancer detection with multispectral photoacoustic imaging. The goal of the PS-ACO-RNN approach is to use ultrasound images to detect and classify the presence of cancer. Bilateral filtration (BF) is often used as a noise removal approach in image processing. In addition, lightweight LEDNet models are used to separate the biological images. A feature extractor with particle swarm with ant colony optimization (PS-ACO) paradigm can also be used. Finally, biological images assign appropriate class labels using a recurrent neural network (RNN) model. The effectiveness of the PS-ACO-RNN technique is verified using a benchmark database, and test results show that the PS-ACO-RNN approach works better than current approaches.

Effect of Sn Substitution on the Thermoelectric Properties of Synthetic Tetrahedrite.

The present study reports the effect of Sn substitution on the structural and thermoelectric properties of synthetic tetrahedrite (Cu12Sb4S13) system. The samples were prepared with the intended compositions of Cu12Sb4- xSn xS13 ( x = 0.25, 0.35, 0.5, 1) and sintered using spark plasma sintering. A detailed structural characterization of the samples revealed tetrahedrite phase as the main phase with Sn substituting at both Cu and Sb sites instead of only Sb site. The theoretical calculations using density functional theory revealed that Sn at Cu(1) 12d or Cu(2) 12e site moves the Fermi level ( EF) toward the band gap, whereas Sn at Sb 8c site introduces hybridized hole states near EF. Consequently, a relatively high optimum power factor of 1.3 mW/mK2 was achieved by the x = 0.35 sample. The Sn-substituted samples exhibited a significant decrease in the total thermal conductivity (κT) compared to the pristine composition (Cu12Sb4S13), primarily because of reduced electronic thermal conductivity. Due to an optimum power factor (1.3 mW/mK2) and reduced thermal conductivity (0.9 W/mK), a maximum zT of 0.96 at 673 K was achieved for x = 0.35 sample, which is nearly 40% increment compared to that of the pristine (Cu12Sb4S13) sample.

Localized Surface Plasmon Resonance in Au Nanoparticles Embedded dc Sputtered ZnO Thin Films.

The plasmonic behavior of metallic nanoparticles is explicitly dependent on their shape, size and the surrounding dielectric space. This study encompasses the influence of ZnO matrix, morphology of Au nanoparticles (AuNPs) and their organization on the optical behavior of ZnO/AuNPs-ZnO/ZnO/GP structures (GP: glass plate). These structures have been grown by a multiple-step physical process, which includes dc sputtering, thermal evaporation and thermal annealing. Different analytical techniques such as scanning electron microscopy, glancing angle X-ray diffraction, Rutherford backscattering spectrometry and optical absorption have been used to study the structures. In-situ rapid thermal treatment during dc sputtering of ZnO film has been found to induce subtle changes in the morphology of AuNPs, thereby altering the profile of the plasmon band in the absorption spectra. The results have been contrasted with a recent study on the spectral response of dc magnetron sputtered ZnO films embedded with AuNPs. Initial simulation results indicate that AuNPs-ZnO/Au/GP structure reflects/absorbs UV and infrared radiations, and therefore can serve as window coatings.

Molecular identification of Campylobacter jejuni and coli from chicken, calves and dogs to determine its potential threat on human being.

AIM: Campylobacter is an emerging zoonotic pathogen and one of the leading cause of foodborne infection worldwide and it has been isolated from a variety of animal species. The aim of this study was to identify Campylobacter jejuni and Campylobacter coli from dogs, calves, and poultry using polymerase chain reaction (PCR). METHODOLOGY: A total of 104 number of samples comprising cloacal swab from poultry (38), a rectal swab from dogs (40), and calves (26) were collected for the isolation of thermophilic Campylobacters using conventional culture method. PCR was used for identification of mapA gene for C.jejuni and ceuE for C.coli. RESULTS: The overall presence of Campylobacter was found to be 67(64.42%) from the samples, out of which 6 isolates belongs to C. jejuni species, were 5(18.51%) from chicken and 1(4.17%) from dog was recorded and about 17 isolates belongs to C. coli species were 9(33.33%), 6 (25%), and 1(9.09%) from chicken, dog and calves was recorded. CONCLUSION: Results suggested that Campylobacter reservoirs chicken, calves and pet dogs can play a role as the source of infection to human beings and PCR can be an ideal tool for molecular confirmation at the species level.

The second generation Singapore high resolution proton beam writing facility.

A new proton beam focusing facility, designed for proton beam writing (PBW) applications has been tested. PBW allows for proximity free structuring of high aspect ratio, high-density 3D nanostructures. The new facility is designed around OM52 compact quadrupole lenses capable of operating in a variety of high demagnification configurations. Performance tests show that proton beams can be focused down to 19.0 × 29.9 nm(2) and single line scans show a beam width of 12.6 nm. The ultimate goal of sub 10 nm structuring with MeV protons will be discussed.