Abstract
We report a low-temperature magneto transport study of Bi
2
Se
3
thin films of different thicknesses (40, 80 and 160 nm), deposited on sapphire (0001) substrates, using radio frequency ...magnetron sputtering technique. The high-resolution x-ray diffraction measurements revealed the growth of rhombohedral c-axis {0003n} oriented Bi
2
Se
3
films on sapphire (0001). Vibrational modes of Bi
2
Se
3
thin films were obtained in the low wavenumber region using Raman spectroscopy. The surface roughness of sputtered Bi
2
Se
3
thin films on sapphire (0001) substrates were obtained to be ~ 2.26–6.45 nm. The chemical and electronic state of the deposited Bi
2
Se
3
was confirmed by X-ray photoelectron spectroscopy and it showed the formation of Bi
2
Se
3
compound. Resistivity versus temperature measurements show the metallic nature of Bi
2
Se
3
films and a slight up-turn transition in resistivity at lower temperatures < 25 K. The positive magneto-resistance value of Bi
2
Se
3
films measured at low temperatures (2–100 K) confirmed the gapless topological surface states in Bi
2
Se
3
thin films. The quantum correction to the magnetoconductivity of thin films in low magnetic field is done by employing Hikami–Larkin–Nagaoka theory and the calculated value of coefficient ‘α’ (defining number of conduction channels) was found to be 0.65, 0.83 and 1.56 for film thickness of 40, 80 and 160 nm, respectively. These observations indicate that the top and bottom surface states are coupled with the bulk states and the conduction mechanism in Bi
2
Se
3
thin films varied with the film thicknesses.
We present results of a search for late-time radio emission and fast radio bursts (FRBs) from a sample of type-I superluminous supernovae (SLSNe-I). We used the Karl G. Jansky Very Large Array to ...observe 10 SLSN-I more than 5 yr old at a frequency of 3 GHz. We searched fast-sampled visibilities for FRBs and used the same data to perform a deep imaging search for late-time radio emission expected in models of magnetar-powered supernovae. No FRBs were found. One SLSN-I, PTF10hgi, is detected in deep imaging, corresponding to a luminosity of 1.2 × 1028 erg s−1. This luminosity, considered with the recent 6 GHz detection of PTF10hgi in Eftekhari et al., supports the interpretation that it is powered by a young, fast-spinning (∼ms spin period) magnetar with ∼15 M of partially ionized ejecta. Broadly, our observations are most consistent with SLSNe-I being powered by neutron stars with fast spin periods, although most require more free-free absorption than is inferred for PTF10hgi. We predict that radio observations at higher frequencies or in the near future will detect these systems and begin constraining properties of the young pulsars and their birth environments.
Essential oils extracted from 10 medicinal plants were evaluated for larvicidal, adulticidal, ovicidal, oviposition-deterrent and repellent activities towards three mosquito species;
Anopheles ...stephensi,
Aedes aegypti and
Culex quinquefasciatus. The essential oils of
Juniperus macropoda and
Pimpinella anisum were highly effective as both larvicidal and ovicidal. The essential oil of
P. anisum showed toxicity against 4th instar larvae of
A. stephensi and
A. aegypti with equivalent LD
95 values of 115.7
μg/ml, whereas it was 149.7
μg/ml against
C. quinquefasciatus larvae. Essential oils of
Zingiber officinale and
Rosmarinus officinalis were found to be ovicidal and repellent, respectively towards the three mosquito species. The essential oil of
Cinnamomum zeylanicum resulted into highest repellent (RD
95) values of 49.6, 53.9 and 44.2
mg/mat against
A. stephensi,
A. aegypti and
C. quinquefasciatus, respectively apart from oviposition-deterrent potential.
16S ribosomal-ribonucleic acid polymerase chain reaction (PCR) and targeted PCR aid microbiological diagnosis in culture-negative clinical samples. Despite routine clinical use, there remains a ...paucity of data on their effectiveness across a variety of clinical sample types, and cost-effectiveness. In this 4 year multicentre retrospective observational study, all clinical samples referred for 16S PCR and/or targeted PCR from a laboratory network serving seven London hospitals were identified. Laboratory, clinical, prescribing, and economic variables were analysed. 78/607 samples were 16S PCR positive; pus samples were most frequently positive (29/84; p < 0.0001), and CSF least (8/149; p = 0.003). 210/607 samples had targeted PCR (361 targets requested across 23 organisms) with 43/361 positive; respiratory samples (13/37; p = 0.01) had the highest detection rate. Molecular diagnostics provided a supportive microbiological diagnosis for 21 patients and a new diagnosis for 58. 14/91 patients with prescribing information available and a positive PCR result had antimicrobial de-escalation. For culture-negative samples, mean cost-per-positive 16S PCR result was £568.37 and £292.84 for targeted PCR, equating to £4041.76 and £1506.03 respectively for one prescription change. 16S PCR is more expensive than targeted PCR, with both assisting in microbiological diagnosis but uncommonly enabling antimicrobial change. Rigorous referral pathways for molecular tests may result in significant fiscal savings.
In view of an exponential increase in the negative impacts of flash-floods globally, the present work aims at the identification of flash-floods-prone river reaches in the Beas river basin, Himachal ...Pradesh, India using a multi-criteria indexing technique. The flood hazard index (FHI) was computed by implementing analytical hierarchy process (AHP) model on 6 hydrologic parameters influencing flood hazard, namely rainfall intensity, curve number (CN) grid, time of travel, slope, Manning's roughness coefficient and drainage density. The CN grid (empirical parameter to estimate direct surface runoff) was used as one of the parameters which depend upon the land use, hydrologic soil group and hydrologic conditions. It is imperative to mention that remote sensing and geographical information system (GIS) techniques played a crucial role in the preparation of these 6 parameter layers. The AHP model calculates the normalized weights for each parameter using pair-wise comparison matrices. The rainfall intensity and curve number were the factors having the highest normalized weight of 34.52 each. Subsequently, the estimated weights of the parameters and hazard level-wise rating scores were used in a GIS environment to generate FHI. The generated FHI raster was masked using floodplain layer within geomorphology map and river buffer to identify flash-floods-affected river reaches. The generated flash-floods map was validated by historical flash-floods ground points, field observations and remote sensing data. The results depicted that the river reaches in the north and east of the Beas basin are susceptible to flash-floods which are mainly governed by heavy rainfall intensity and high runoff characteristics. The river stretches namely Bahang–Manali (Beas), Kullu–Bhuntar (Beas) and Manikaran–Kheer-Ganga (Parvati) have been categorized into very high and high flash-floods zones. Decreasing trend of normalized differential vegetation index (NDVI) was observed for river reaches falling within the very high and high zones indicating the vegetation loss post successive flash-floods events. The river order 2 lies in the very high and high flash-floods zones, indicating the fact that the contribution of tributaries is significant to flood events. Flash-floods map will serve as catastrophic product, which will help policymakers to take suitable measures to reduce the risk of flash-floods.
Thin films of Bi
2
Se
3
were deposited on various substrates such as sapphire (0001), quartz, and GaN/sapphire (0001) using magnetron sputtering. The crystalline quality of deposited thin films was ...studied by high-resolution X-ray diffraction and {0003
n
} diffraction confirms that the films are oriented along the
c
-axis. Raman spectroscopy measurements revealed the pure rhombohedral phase of Bi
2
Se
3
thin films. These films possess truncated hexagonal morphology, and elemental analysis showed stoichiometric Bi
2
Se
3
. The chemical and electronic states of the Bi
2
Se
3
thin films were validated by X-ray photoelectron spectroscopy which revealed the formation of Bi
2
Se
3
compound. The optical properties of the Bi
2
Se
3
thin films were studied using broadband absorption spectroscopy and the optical bandgap of Bi
2
Se
3
thin films (~ 150 nm) was found in the range of 1.40–1.48 eV. The Bi
2
Se
3
thin film deposited using magnetron sputtering with good structural and optical quality will pave the way for the development of futuristic devices.
Graphical abstract
Phage therapy is a viable alternative to antibiotics for treating microbial infections, particularly managing drug-resistant strains of bacteria. One of the major challenges in designing phage-based ...therapy is to identify the most appropriate potential phage candidate to treat bacterial infections. In this study, an attempt has been made to predict phage-host interactions with high accuracy to identify the potential bacteriophage that can be used for treating a bacterial infection. The developed models have been created using a training dataset containing 826 phage- host interactions, and have been evaluated on a validation dataset comprising 1,201 phage-host interactions. Firstly, alignment-based models have been developed using similarity between phage-phage (BLASTPhage), host-host (BLASTHost) and phage-CRISPR (CRISPRPred), where we achieved accuracy between 42.4-66.2% for BLASTPhage, 55-78.4% for BLASTHost, and 43.7-80.2% for CRISPRPred across five taxonomic levels. Secondly, alignment free models have been developed using machine learning techniques. Thirdly, hybrid models have been developed by integrating the alignment-free models and the similarity-scores where we achieved maximum performance of (60.6-93.5%). Finally, an ensemble model has been developed that combines the hybrid and alignment-based models. Our ensemble model achieved highest accuracy of 67.9, 80.6, 85.5, 90, and 93.5% at Genus, Family, Order, Class, and Phylum levels on validation dataset. In order to serve the scientific community, we have also developed a webserver named PhageTB and provided a standalone software package (https://webs.iiitd.edu.in/raghava/phagetb/) for the same.
This study aimed to identify suitable sites for tea cultivation using both random forest and logistic regression models. The study utilized 2770 sample points to map the tea plantation suitability ...zones (TPSZs), considering 12 important conditioning factors, such as temperature, rainfall, elevation, slope, soil depth, soil drainability, soil electrical conductivity, base saturation, soil texture, soil pH, the normalized difference vegetation index (NDVI), and land use land cover (LULC). The data were normalized using ArcGIS 10.2 and the models were calibrated using 70% of the total data, while the remaining 30% of the data were used for validation. The final TPSZ map was classified into four different categories: highly suitable zones, moderately suitable zones, marginally suitable zones, and not-suitable zones. The study revealed that the random forest (RF) model was more precise than the logistic regression model, with areas under the curve (AUCs) of 85.2% and 83.3%, respectively. The results indicated that well-drained soil with a pH range between 5.6 and 6.0 is ideal for tea farming, highlighting the importance of climate and soil properties in tea cultivation. Furthermore, the study emphasized the need to balance economic and environmental considerations when considering tea plantation expansion. The findings of this study provide important insights into tea cultivation site selection and can aid tea farmers, policymakers, and other stakeholders in making informed decisions regarding tea plantation expansion.
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