The Transition Radiation Detector (TRD) was designed and built to enhance the capabilities of the ALICE detector at the Large Hadron Collider (LHC). While aimed at providing electron identification ...and triggering, the TRD also contributes significantly to the track reconstruction and calibration in the central barrel of ALICE. In this paper the design, construction, operation, and performance of this detector are discussed. A pion rejection factor of up to 410 is achieved at a momentum of 1 GeV/ in p–Pb collisions and the resolution at high transverse momentum improves by about 40% when including the TRD information in track reconstruction. The triggering capability is demonstrated both for jet, light nuclei, and electron selection.
Spread of antibiotic resistant bacteria through water pose severe health risks to society. In this context, a systematic study is reported for photocatalytic removal of multidrug resistant (MDR) ...Escherichia coli and related genes from water by using Alumina/ZnO heterostructures under visible light. 500 mg/L of the photocatalyst could disinfect ≈ 106 CFU/mL of target bacteria in water within 240 min of visible light irradiation. Lipid peroxidation, DNA and protein leakage studies have suggested the compromisation of bacterial cell membrane which was further corroborated from electron microscopy images. MDR Escherichia coli has registered a loss of resistance towards fifteen antibiotics with a down-regulation in the antibiotic resistance genes after exposure to photocatalytic process. Proposed process was also validated for disinfection of MDR Staphylococcus haemolyticus and antibiotic susceptible Escherichia coli. Successful disinfection of fecal coliform was achieved in water samples collected from three major rivers and a waste water treatment plant. The in vivo toxicity study of the treated water on mice model has not revealed any remarkable impact on gut health. With high effectiveness in disinfecting bacteria coupled with biocompatibility of the treated water towards animal model may proffer the present technique as a propitious off-grid water disinfection technique for real-world applications.
A systematic study is reported for Photocatalytic removal of Extended-spectrum beta-lactamase producing Escherichia coli and related genes from water using Alumina/ZnO heterostructures under visible light. Display omitted
•Photocatalytic disinfection of ESBL-producing E. coli using Alumina/ZnO under visible light is reported.•Lipid peroxidation, DNA and protein leakage studies have suggested the compromisation of bacterial cell membrane.•After photocatalysis, E. coli registered a loss of antibiotic resistance and down-regulation in the resistance genes.•Process was validated for disinfection of antibiotic resistant S. haemolyticus and antibiotic susceptible E. coli.•Successful disinfection of fecal coliform was achieved in real water.
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•PFLD of Escherichia coli using M/biochar under visible light is reported.•Microscopic evaluations suggested detrimental effects on the bacterial membrane.•Resazurin assay suggested ...the hindrance of metabolic activity of PCD treated cells.•Treatment of M/biochar with HCT-116 cell lines showed ≈80 % cell viability.•PFLD treated water did not show any remarkable toxicity on growth of maize plants.
Waterborne diseases caused by bacterial contamination of water sources remain one of the perilous public health challenges in low and middle-income countries. In this regards, we report a photo-Fenton like reaction for disinfection of water contaminated with common waterborne bacterium, Escherichia coli under visible light using biochar supported maghemite nanoparticles (M/biochar). Waste leaves of Cymbopogon flexuosus impregnated with ferric chloride were subjected to pyrolysis, which leads to the formation of M/biochar. M/biochar was found to be more effective than only Maghemite nanoparticles for disinfection of targeted bacterium in a photo-Fenton like process. Fluorescence and scanning electron microscopy images indicated compromization of bacterial cell membrane. Experimental evidence infers that hydroxyl radicals could be the major component responsible for disinfecting E. coli in the present process. Results obtained from Resazurin assay indicate that reactive oxygen species produced during photo-Fenton like reaction may have impeded the oxido-reductase protein system of the bacteria and hence hampered its metabolic activity. Proposed process has been successfully investigated for disinfection of real water samples contaminated with E. coli and treated water did not induce a noticeable toxic effect on the growth of maize plants and hence could have the potential for real world applications.
Ninety six accessions including 92 of
Solanum melongena and four related non-tuberous species (
Solanum insanum,
S. incanum,
S. integrifolium and
S. sysimbriifolium) were taken for the assessment of ...genetic diversity using 23 STMS primers. Eleven of the 23 primers tested showed polymorphism. The number of alleles per primer ranged from three to six with an average of 4.4.
S. melongena had maximum average similarity with its closely related species,
S. insanum (0.67) and minimum average similarity with the wild species,
S. sysimbriifolium (0.50). The two weedy species
S. incanum and
S. integrifolium showed more average similarity value of 0.62 and 0.61, respectively with the cultivated
S. melongena.
S. insanum.
S. incanum and
S. integrifolium were relatively similar to each other with similarity index value of 0.61 (between
S. insanum and
S. incanum), 0.63 (between
S. insanum and
S. integrifolium) and 0.62 (between
S. incanum and
S. integrifolium). In contrast
S. sysimbriifolium was most divergent with the similarity value of 0.49, 0.47 and 0.51 with
S. insanum,
S. incanum and
S. integrifolium, respectively. The closely related species
S. insanum and
S. incanum, which clustered along with
S. melongena accessions, being crossable with cultivated species, constitute important sources of genes that can be introgressed by backcross breeding. Molecular markers can be employed to identify the hybrids and also to monitor introgression of the useful genes.
The effect of acclimation to high irradiance stress (HIS, 250 W m
−2) in wheat leaves grown under three different irradiances was investigated by HPLC analyses of pigments, chlorophyll
a fluorescence ...parameters and photochemical activities of chloroplasts. Significant loss of β-carotene was observed compared to the xanthophylls in all three types of seedlings exposed to HIS. However, the effect of HIS on neoxanthin and lutein contents was not significant. The loss of partial electron transport (Asc-DCPIP to MV, PS I activity) was less than the whole chain (H
2O to MV) and PS II activity (H
2O to DCPIP) suggesting that PS I is less susceptible to HIS compared to PS II. The percent of reductions in Fv/Fm and Φ
PS II were less in plants grown under high irradiance (HI-1, 30 W m
−2 and HI-2, 45 W m
−2) compared to those grown under moderate irradiance (MI, 15 W m
−2). On the other hand, the percent of NPQ increased more in the leaves of HI plants compared to the leaves of MI when exposed to HIS which suggests a more efficient non-radiative dissipation of excess excitation energy in HI plants compared to MI. These observations suggest that plants grown under relatively high irradiance are better adapted to HIS condition.
Remarkable changes were observed in chlorophyll (Chl) (
a+
b), carotenoids (Car), and protein content of leaves and fluorescence emission, polarisation, excitation energy transfer, lipid peroxidation ...and DCPIP photoreduction activity in isolated chloroplasts of wheat leaves grown under moderate irradiance (MI, 15 W m
−2, control) and subsequently exposed to high irradiance stress (HIS, 250 W m
−2), water stress (WS, 5 % aqueous polyethylene glycol-4000 solution) and HIS+WS simultaneously, during mature and senescence phase. In the stress exposed samples the Chl, Car and protein contents and kinetics of Hill activity significantly declined. Decrease in excitation energy transfer and increase in membrane polarisation and accumulation of malondialdehyde (MDA) in chloroplasts were also observed. The effect was more pronounced when the seedlings were treated with HIS+WS simultaneously. These observations suggest additive and a possible synergetic action of HIS and WS causing faster loss of pigments and protein content, intense changes in membrane properties including photochemical function, compared to samples exposed to either of the stresses individually.
The chlorophyll (Chl) fluorescence emission as well as excitation and polarization characteristics of chloroplasts from intact cotyledons were determined in pumpkin seedlings after removal of one ...cotyledon or apical bud or primary root, or after kinetin treatment of derooted seedlings. Qualitatively, the fluorescence emission and excitation spectra of chloroplasts were similar. The fluorescence emission spectra showed a maximum at 685 (F685) and a hump at 735 nm (F735), whereas the excitation spectra showed peaks at 439, 471, 485, and 676 nm. The fluorescence intensities at F685 and F735 differed in various groups of seedlings, as indicated by changes in their ratios. Similarly, the ratios of 471/439, 485/439, and 676/439 nm were also different. Kinetin treatment improved the coupling of pigment complexes with reaction centre, as indicated by low polarization values in derooted and kinetin-treated seedlings, which suggests the development of a suntype chloroplast.
