Genome-wide mining of diversity and evolutionary signatures revealed selective hotspots in Indian Sahiwal cattle

The Sahiwal cattle breed is the best indigenous dairy cattle breed, and it plays a pivotal role in the Indian dairy industry. This is due to its exceptional milk-producing potential, adaptability to local tropical conditions, and its resilience to ticks and diseases. The study aimed to identify selective sweeps and estimate intrapopulation genetic diversity parameters in Sahiwal cattle using ddRAD sequencing-based genotyping data from 82 individuals. After applying filtering criteria, 78,193 high-quality SNPs remained for further analysis. The population exhibited an average minor allele frequency of 0.221 ± 0.119. Genetic diversity metrics, including observed (0.597 ± 0.196) and expected heterozygosity (0.433 ± 0.096), nucleotide diversity (0.327 ± 0.114), the proportion of polymorphic SNPs (0.726), and allelic richness (1.323 ± 0.134), indicated ample genomic diversity within the breed. Furthermore, an effective population size of 74 was observed in the most recent generation. The overall mean linkage disequilibrium (r2) for pairwise SNPs was 0.269 ± 0.057. Moreover, a greater proportion of short Runs of Homozygosity (ROH) segments were observed suggesting that there may be low levels of recent inbreeding in this population. The genomic inbreeding coefficients, computed using different inbreeding estimates (FHOM, FUNI, FROH, and FGROM), ranged from -0.0289 to 0.0725. Subsequently, we found 146 regions undergoing selective sweeps using five distinct statistical tests: Tajima's D, CLR, |iHS|, |iHH12|, and ROH. These regions, located in non-overlapping 500 kb windows, were mapped and revealed various protein-coding genes associated with enhanced immune systems and disease resistance (IFNL3, IRF8, BLK), as well as production traits (NRXN1, PLCE1, GHR). Notably, we identified interleukin 2 (IL2) on Chr17: 35217075-35223276 as a gene linked to tick resistance and uncovered a cluster of genes (HSPA8, UBASH3B, ADAMTS18, CRTAM) associated with heat stress. These findings indicate the evolutionary impact of natural and artificial selection on the environmental adaptation of the Sahiwal cattle population.

Stable isotope labeling as a promising tool for rapid drug susceptibility testing in Neisseria gonorrhoeae

The world is heading towards an era of intractable and impending untreatable N. gonorrhoeae, thereby underlining the significance of rapid and accurate prediction of drug resistance as an indispensable need of the hour. In the present study, we optimized and evaluated a stable isotope labeling-based approach using the MALDI-TOF MS (Matrix-Assisted Laser Desorption/Ionization-Time of Flight Mass Spectrometry) for rapid and reliable detection of ciprofloxacin and azithromycin resistance in N. gonorrhoeae. All the isolates were cultured under three varied condition setups viz. medium supplemented with normal lysine, heavy lysine (isotope), and heavy lysine along with the antibiotics (ciprofloxacin/azithromycin), respectively. After incubation, spectra were acquired using the MALDI-TOF MS which were further screened for unique patterns (media-specific spectra) to differentiate drug-susceptible and resistant isolates. The results of the stable isotope labeling assay were comparable to the results of phenotypic methods used for susceptibility testing.

Remote ischaemic conditioning: defining critical criteria for success-report from the 11th Hatter Cardiovascular Workshop

The Hatter Cardiovascular Institute biennial workshop, originally scheduled for April 2020 but postponed for 2 years due to the Covid pandemic, was organised to debate and discuss the future of Remote Ischaemic Conditioning (RIC). This evolved from the large multicentre CONDI-2-ERIC-PPCI outcome study which demonstrated no additional benefit when using RIC in the setting of ST-elevation myocardial infarction (STEMI). The workshop discussed how conditioning has led to a significant and fundamental understanding of the mechanisms preventing cell death following ischaemia and reperfusion, and the key target cyto-protective pathways recruited by protective interventions, such as RIC. However, the obvious need to translate this protection to the clinical setting has not materialised largely due to the disconnect between preclinical and clinical studies. Discussion points included how to adapt preclinical animal studies to mirror the patient presenting with an acute myocardial infarction, as well as how to refine patient selection in clinical studies to account for co-morbidities and ongoing therapy. These latter scenarios can modify cytoprotective signalling and need to be taken into account to allow for a more robust outcome when powered appropriately. The workshop also discussed the potential for RIC in other disease settings including ischaemic stroke, cardio-oncology and COVID-19. The workshop, therefore, put forward specific classifications which could help identify so-called responders vs. non-responders in both the preclinical and clinical settings.

Association of ischemic electrocardiographic changes in high-altitude areas with coronary angiography

Background

Soldiers native to lowlands, while sojourning at high altitude (HA), are referred to tertiary care centers with electrocardiographic (ECG) abnormalities. Exposure to HA may precipitate myocardial ischemia in subjects with underlying coronary artery disease (CAD). Conversely, it may produce physiological ECG changes mimicking those of CAD, causing a diagnostic dilemma. This study sought to correlate the presence of CAD on coronary angiography (CAG) with a putative diagnosis of CAD based on clinical findings and ECG.

Methods

A prospective study was conducted on patient's from HA areas, referred for evaluation for CAD to a single center at near-sea-level. Thirty-five minimally symptomatic/asymptomatic soldiers with ECG changes suggestive of CAD, underwent CAG. Correlation was sought between ECG and CAG evidence of CAD.

Results

The association of CAD on CAG with clinical and ECG diagnosis of CAD was not significant, 4 of the 35 soldiers (11.4%) showing CAG evidence of CAD (chi square 3.849, p = 0.697). The association between symptoms and coronary artery lesions was, also, not significant, only four of twenty-three (17.4%) minimally symptomatic subjects having CAD on CAG.

Conclusion

Insignificant numbers of previously healthy persons, who present with minimal symptoms and ECG changes suggestive of CAD while sojourning at HA, have coronary artery involvement on CAG. Those with incidental ECG changes, without symptomatology, do not have CAD on CAG.

Association between overcrowded households, multigenerational households, and COVID-19: a cohort study

OBJECTIVES

The role of overcrowded and multigenerational households as a risk factor for COVID-19 remains unmeasured. The objective of this study is to examine and quantify the association between overcrowded and multigenerational households and COVID-19 in New York City (NYC).

STUDY DESIGN

Cohort study.

METHODS

We conducted a Bayesian ecological time series analysis at the ZIP Code Tabulation Area (ZCTA) level in NYC to assess whether ZCTAs with higher proportions of overcrowded (defined as the proportion of the estimated number of housing units with more than one occupant per room) and multigenerational households (defined as the estimated percentage of residences occupied by a grandparent and a grandchild less than 18 years of age) were independently associated with higher suspected COVID-19 case rates (from NYC Department of Health Syndromic Surveillance data for March 1 to 30, 2020). Our main measure was an adjusted incidence rate ratio (IRR) of suspected COVID-19 cases per 10,000 population. Our final model controlled for ZCTA-level sociodemographic factors (median income, poverty status, White race, essential workers), the prevalence of clinical conditions related to COVID-19 severity (obesity, hypertension, coronary heart disease, diabetes, asthma, smoking status, and chronic obstructive pulmonary disease), and spatial clustering.

RESULTS

39,923 suspected COVID-19 cases were presented to emergency departments across 173 ZCTAs in NYC. Adjusted COVID-19 case rates increased by 67% (IRR 1.67, 95% CI = 1.12, 2.52) in ZCTAs in quartile four (versus one) for percent overcrowdedness and increased by 77% (IRR 1.77, 95% CI = 1.11, 2.79) in quartile four (versus one) for percent living in multigenerational housing. Interaction between both exposures was not significant (β_interaction = 0.99, 95% CI: 0.99-1.00).

CONCLUSIONS

Overcrowdedness and multigenerational housing are independent risk factors for suspected COVID-19. In the early phase of the surge in COVID cases, social distancing measures that increase house-bound populations may inadvertently but temporarily increase SARS-CoV-2 transmission risk and COVID-19 disease in these populations.

Roles of Re-entrant cluster glass state and spin-lattice coupling in magneto-dielectric behavior of giant dielectric double perovskite La1.8Pr0.2CoFeO6

La based Co-Fe combined double perovskite (La1.8Pr0.2CoFeO6) was synthesized and the dielectric (zero-field and in-field), magnetic, x-ray absorption and Raman spectroscopy measurements have been investigated for La1.8Pr0.2CoFeO6 double perovskite. The existence of re-entrant cluster glass state is observed. The magneto-dielectric (MD) is found in two temperature regions (25-80 K and 125-275 K). It has been demonstrated that the observed MD at low and high temperatures are respectively due to the spin freezing and the spin-lattice coupling. Furthermore, the very large dielectric constant and the low loss suggest that La1.8Pr0.2CoFeO6 is very important from the application point of view.

Extraordinary magnetic properties of double perovskite Eu2CoMnO6 wide band gap semiconductor

Some novel magnetic behaviours in double perovskite Eu2CoMnO6 (ECMO) have been reported. The x-ray photoemission spectroscopy study shows the presence of mixed valence states of transition metal ions. The UV-visible absorption spectroscopic study suggests that the ECMO has a direct wide band gap. A second-order magnetic phase transition as a sudden jump in the magnetization curve has been observed around 124.5 K. The large bifurcation between the zero field cooling and field cooling, suggests existence of strong spin frustration in the system. The inverse DC susceptibility confirms the presence of the Griffiths like phase. Sharp steps in magnetization have been observed in the M-H curve at 2 K, which vanishes on increasing temperature. The AC susceptibility study demonstrates the Hopkinson like effect as well as the presence of volume spin-glass-like behaviour. The temperature dependent Raman spectrum shows the presence of spin-phonon coupling.

Anomalous Hall effect in Cu doped Bi2Te3 topological insulator

The angle resolved photo-emission spectroscopy (ARPES) study and magneto-transport properties of Bi2Cu x Te3-x have been investigated. ARPES study indicates the clear existence of surface states in the as-prepared samples. The estimated bandgap from ARPES is found to be ∼5 meV and 16 meV respectively for x = 0.03 and x = 0.15 samples. Presence of larger Cu concentration (x = 0.15) introduces magnetic ordering. Observed non-linearity in the Hall data is due to the existence of anomalous Hall effect which can be attributed to the 2D transport. The observed magneto-transport features might be related to the surface carriers which is confirmed by ARPES study.

P680The clinical value of CMR in the management of Cardio-Oncology patients - a tertiary centre experience

Background

There is increasing awareness of cardiotoxicity arising from cancer treatments. Early diagnosis and treatment is key, to ensure patients receive optimal oncological management. Cardiovascular magnetic resonance (CMR) offers gold standard measurement of cardiac function, alongside tissue characterisation and myocardial perfusion, thereby potentially providing additive value in the context of cardio-oncology.

Purpose

We sought to understand the clinical value of CMR in cardio-oncology at a tertiary cardio-oncology centre.

Methods

We retrospectively reviewed CMR scans requested in cardio-oncology patients at our institution within a ten-month period. We categorised clinical indications and assessed the impact on clinical management using previously-published criteria.

Results

102 CMR studies were requested in 93 cardio-oncology patients (mean age 56 (range 18 to 82), 49% male) between (March to December 2018). 41% of patients had haematological malignancies, 59% solid tumours.

15% of requests were for risk stratification prior to initiation of cancer therapy, 21% for screening for cardio-toxicity in patients currently receiving cardiotoxic agents (3% anthracyclines, 13% HER2 monoclonal antibodies, 4% fluoropyrimidines), 15% for investigation of patients with cardiac complications during cancer treatment, 35% assessment for late effects post cancer treatment, and 14% for cardiac malignancies/ infiltration.

The most common indications for CMR were monitoring of left ventricular ejection fraction (LVEF) in patients where quantification by echocardiography was non-diagnostic or significantly different between imaging studies (39%) and ischaemia assessment including for patients due to receive fluoropyrimidines (26%). Others were aetiology of LV dysfunction/cardiomyopathy (13%) and tissue characterisation (23%), including assessment for cardiac AL amyloid (11 patients), myocarditis (2), cardiac metastases (1), cardiac masses (6), and cardiac iron loading (1).

CMR findings had clinical impact in 61% of patients and assisted in adjudicating a new diagnosis in 29% of patients. 88% of patients were able to continue anthracycline/anti-HER2 therapies based on CMR findings of stable LVEF (93% of whose echocardiograms had suggested reductions). LVEF had reduced significantly in 12% of patients meaning chemotherapy was held/discontinued. 3 patients were recommended to receive non-fluoropyrimidine chemotherapy based on perfusion CMR (pCMR) findings, with one patient permitted to receive capecitabine following normal pCMR.

Conclusion

CMR provides a comprehensive assessment of myocardial structure and function with utility within the context of cardio-oncology for risk stratification pre-chemotherapy, screening for cardiotoxicity during treatment and investigation of cardiac complications of cancer treatment. The additional information derived from CMR generally provides reassurance enabling administration of optimal cancer therapies.

Investigation of multi-mode spin-phonon coupling and local B-site disorder in Pr2CoFeO6 by Raman spectroscopy and correlation with its electronic structure by XPS and XAS studies

Electronic structure of Pr₂CoFeO₆ (at 300 K) was investigated by x-ray photoemission spectroscopy (XPS) and x-ray absorption spectroscopy techniques. All three cations, i.e. Pr, Co and Fe were found to be trivalent in nature. XPS valance band analysis suggested the system to be insulating in nature. The analysis suggested that Co³⁺ ions exist in low spin state in the system. Moreover, Raman spectroscopy study indicated the random distribution of the B-site ions (Co/Fe) triggered by same charge states. In temperature-dependent Raman study, the relative heights of the two observed phonon modes exhibited anomalous behaviour near magnetic transition temperature T _N ~ 270 K, thus indicating towards interplay between spin and phonon degrees of freedom in the system. Furthermore, clear anomalous softening was observed below T _N which confirmed the existence of strong spin-phonon coupling occurring for at least two phonon modes of the system. The line width analysis of the phonon modes essentially ruled out the role of magnetostriction effect in the observed phonon anomaly. The investigation of the lattice parameter variation across T _N (obtained from the temperature-dependent neutron diffraction measurements) further confirmed the existence of the spin-phonon coupling.

Identification of Malassezia species by MALDI-TOF MS after expansion of database

The taxonomy of Malassezia species is evolving with introduction of molecular techniques, and difficulty is faced to identify the species by phenotypic methods. Among 15 known Malassezia species, the present Bruker database could identify only 2 species. The present study was aimed to improve Matrix -assisted laser desorption ionization time-flight mass spectrometry (MALDI-TOF MS) based identification of Malassezia species. A total of 88 isolates (DNA sequencing confirmed) for database preparation and, for the validation of database, 190 isolates confirmed by polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) were used. The main spectrum profile dendrogram showed the sufficient discrimination between all the species by MALDI-TOF MS. The updated Malassezia database could identify 94.7% and 5.3% strains to the species and genus level, respectively. MALDI-TOF MS is a significantly reliable technique, and results were comparable with PCR-RFLP with kappa value 0.9. In conclusion, MALDI-TOF MS could be a possible alternative tool to other molecular methods for rapid and accurate identification of Malassezia species.

Investigations on Blending and Foaming Behavior of Styrene-Ethylene-Butylene-Styrene/Polystyrene Blends

The interplay of screw speed and residence time during polymer blend extrusion profoundly influences blend properties. Herein, blends of styrene-ethylene-butylene-styrene (SEBS) and polystyrene (PS) containing 30% by weight PS were prepared at a constant feed rate but different screw speeds (50, 100, 200 and 300 min−1). The blend produced at 100 min−1 (B100) possessed a finer morphology, better mechanical and rheological properties, attributed to suitability of residence time and viscosity ratio. When batch foamed with carbon dioxide at 110°C and 100°C, all blends produced stable foams. B100 foams exhibited higher volume expansion ratio (VE) due to higher complex viscosity and storage modulus. When foaming was conducted at 35°C, all foams shrank. B100 foams possessed higher cell density, lower VE and showed faster shrinkage due to increased nucleation and hindered expansion by the finely dispersed stiff PS aggregates during selective foaming of the elastomeric phase.

Biosynthesis and characterization of gold nanoparticles: Kinetics, in vitro and in vivo study

This study reports a facile, cost effective, nontoxic and eco-friendly method for the synthesis of gold nanoparticles. In this paper, leaf extract of Mentha piperita was successfully used to reduce chloroauric acid, leading to synthesis of gold nanoparticles (AuNPs). The synthesized nanoparticles were further characterized by UV-visible spectroscopy, Fourier transform infrared spectroscopy, dynamic light scattering, transmission electron microscopy and field emission scanning electron microscopy. Kinetics studies like effect of volume of leaf extract, precursor, pH, temperature for the synthesis of AuNPs were studied spectrophotometrically. Synthesized AuNPs were found to possess hexagon structure where size of nanoparticles was ~78nm in diameter. These biologically synthesized AuNPs exhibited significant activity against cancerous cell lines MDA-MB-231 and A549 and was compared with the normal 3T3-L1 cell line. Anti-inflammatory and analgesic activities were studied on a Wistar rat model to gauge the impact of AuNPs for a probable role in these applications. AuNPs gave positive results for both these activities, although the potency was less as compared to the standard drugs. These results suggested that the leaves extract of Mentha piperita is a very good bioreductant for the synthesis of AuNPs and have potential for various biomedical and pharmaceutical applications.

Structural investigations of (Mn, Dy) co-doped ZnO nanocrystals using X-ray absorption studies

EXAFS measurements on sol gel derived (Mn, Dy) co-doped ZnO nanocrystals show that oxygen vacancies are created near the Dy sites into ZnO lattice. Thus, oxygen vacancy assisted bound magnetic polarons contribute to the RTFM in the Dy doped samples.

Large power factor and anomalous Hall effect and their correlation with observed linear magneto resistance in Co-doped Bi2Se3 3D topological insulator

Magnetoresistance (MR), thermo power, magnetization and Hall effect measurements have been performed on Co-doped Bi2Se3 topological insulators. The undoped sample shows that the maximum MR as a destructive interference due to a π-Berry phase leads to a decrease of MR. As the Co is doped, the linearity in MR is increased. The observed MR of Bi2Se3 can be explained with the classical model. The low temperature MR behavior of Co doped samples cannot be explained with the same model, but can be explained with the quantum linear MR model. Magnetization behavior indicates the establishment of ferromagnetic ordering with Co doping. Hall effect data also supports the establishment of ferromagnetic ordering in Co-doped Bi2Se3 samples by showing the anomalous Hall effect. Furthermore, when spectral weight suppression is insignificant, Bi2Se3 behaves as a dilute magnetic semiconductor. Moreover, the maximum power factor is observed when time reversal symmetry (TRS) is maintained. As the TRS is broken the power factor value is decreased, which indicates that with the rise of Dirac cone above the Fermi level the anomalous Hall effect and linearity in MR increase and the power factor decreases.

Dynamics of microvesicle generation in B-cell chronic lymphocytic leukemia: implication in disease progression

Previously, we reported that B-cell chronic lymphocytic leukemia (CLL) patients contained elevated levels of microvesicles (MVs). However, given the quiescent nature of CLL B-cells and the relative indolence of the disease, the dynamics of MV generation and their unique phenotypes are not clearly defined. In this study, we find that CLL B-cells generate MVs spontaneously and can be further induced by B-cell receptor-ligation. Most interestingly, CLL B-cells predominantly generate CD52⁺ MVs, but not CD19⁺ MVs in vitro, suggesting preferential usage of CD52 into leukemic-MVs and that the CLL plasma MV phenotypes corroborate well with the in vitro findings. Importantly, we detected increased accumulation of CD52⁺ MVs in previously untreated CLL patients with progressive disease. Finally, sequential studies on MVs in pre- and post-therapy CLL patients demonstrate that while the plasma CD52⁺ MV levels drop significantly after therapy in most and remain at low levels in some patients, a trend of increased accumulation of CD52⁺ MVs was detected in majority of post-therapy CLL patients (25 of 33). In total this study emphasizes that dynamic accumulation of CD52⁺ MVs in plasma can be used to study CLL progression and may be a useful biomarker for patients as they progress and require therapy.

Using chlamydia positivity to estimate prevalence: evidence from the Chlamydia Screening Pilot in England

Studies have suggested that positivity can be used to estimate the prevalence of Chlamydia trachomatis in large-scale chlamydia screening programmes. A recent pilot of opportunistic screening in England estimated that the prevalence among 16–24-year-old women in Portsmouth and Wirral was 9.8% and 11.2%, respectively. This study assessed the continued validity of positivity as an approximate for prevalence. We re-analysed data from the Chlamydia Screening Pilot to estimate positivity, calculated as total positive tests divided by total tests, and compared these estimates with the previously reported prevalence, measured as the number of women testing positive divided by the total number of women screened. Overall positivity was 9.4% in Portsmouth and 11.0% in the Wirral; these estimates were not statistically different from prevalence, regardless of health-care setting, age group or symptoms. We conclude that positivity can be used as a proxy for prevalence.

The prevalence of abnormal ECG in trained sportsmen

BACKGROUND

Competitive sports training causes structural and conductive system changes manifesting by various electrocardiographic alterations. We undertook this study to assess the prevalence of abnormal ECG in trained Indian athletes and correlate it with the nature of sports training, that is endurance or strength training.

METHODS

We evaluated a standard resting, lying 12 lead Electrocardiogram (ECG) in 66 actively training Indian athletes. Standard diagnostic criteria were used to define various morphological ECG abnormalities.

RESULTS

33/66 (50%) of the athletes were undertaking endurance training while the other 33 (50%) were involved in a strength-training regimen. Overall 54/66 (81%) sportsmen had significant ECG changes. 68% of these changes were considered as normal training related features, while the remaining 32% were considered abnormal. There were seven common training related ECG changes-Sinus Bradycardia (21%), Sinus Arrhythmia (16%), 1st degree Atrioventricular Heart Block (6%), Type 1 2nd-degree Atrioventicular Heart Block (3%), Incomplete Right bundle branch block (RBBB) (24%), Early Repolarization (42%), Left Ventricular Hypertrophy (LVH) (14%); while three abnormal ECG changes--T-wave inversion (13%), RBBB(4%), Right ventricular hypertrophy (RVH) with strain (29%) were noted. Early repolarization (commonest change), sinus bradycardia, and incomplete RBBB were the commoner features noticed, with a significantly higher presence in the endurance trained athletes.

CONCLUSION

A high proportion of athletes undergoing competitive level sports training are likely to have abnormal ECG recordings. Majority of these are benign, and related to the physiological adaptation to the extreme levels of exertion. These changes are commoner during endurance training (running) than strength training (weightlifting).

Sensitivity study with respect to direction of ADI method during re-flooding in AHWR

The Advanced Heavy water Reactor (AHWR) is a natural circulation vertical pressure tube type boiling light water cooled and heavy water moderated reactor. As the AHWR fuel bundle quenching under accident condition is designed primarily with radial jets at several axial locations, bottom re-flooding still remain open as another option. Radial direction injection of emergency core cooling leads to rewetting of AHWR fuel cluster in circumferential direction. A 3D fuel pin model has been developed by using Finite Difference Method (FDM) of transient heat conduction equation. Alternating Direction Implicit technique of Finite Difference Method (FDM) has been used for discretisation of numerical equation in different time step at different direction. Sensitivity numerical study with respect to direction of ADI method has been carried out to optimize the time step during the transient as well as steady state and is found that it is insensitivity with direction of solution. Further, to assess influence of circumferential rewetting vis-à-vis axial rewetting. Both the analyses are carried out with same fluid temperature and heat transfer coefficients as boundary conditions. It has been found from the analyses that for radial jet, the circumferential conduction is significant and overall the fuel temperature falls in the quench plane with the initiation of quenching event. The paper discusses the sensitivity study with respect to direction of ADI solution and comparison of numerical results for circumferential and axial rewetting for single pin.

Structural, transport and optical properties of (La0.6Pr0.4)0.65Ca0.35MnO3 nanocrystals: a wide band-gap magnetic semiconductor

(La0.6Pr0.4)0.65Ca0.35MnO3 system has been synthesized via a sol-gel route at different sintering temperatures. Structural, transport and optical measurements have been carried out to investigate (La0.6Pr0.4)0.65Ca0.35MnO3 nanoparticles. Raman spectra show that Jahn-Teller distortion has been decreased due to the presence of Ca and Pr in A-site. Magnetic measurements provide a Curie temperature around 200 K and saturation magnetization (MS) of about 3.43μB/Mn at 5 K. X-ray photoemission spectroscopy study suggests that Mn exists in a dual oxidation state (Mn(3+) and Mn(4+)). Resistivity measurements suggest that charge-ordered states of Mn(3+) and Mn(4+), which might be influenced by the presence of Pr, have enhanced insulating behavior in (La0.6Pr0.4)0.65Ca0.35MnO3. Band gap estimated from UV-Vis spectroscopy measurements comes in the range of wide band gap semiconductors (∼3.5 eV); this makes (La0.6Pr0.4)0.65Ca0.35MnO3 a potential candidate for device application.

Formation of nano-structured core–shell micro-granules by evaporation induced assembly

Nano-structured spherical micro-granules of core–shell morphology have been realized by utilizing the contrasting interfacial interaction of two different types of nano-particles with liquid solvent.

Surface enhanced Raman scattering investigation of two novel piperazine carbodithioic acids adsorbed on Ag and ZnO nanoparticles

In this work piperazine-1-carbodithioic acid (PZCDT) and piperazine-1,4-dicarbodithioic acid (PZbCDT) were synthesized and SERS investigation with Ag & ZnO nanoparticles has been done.

Magnetic and optical properties of Fe doped crednerite CuMnO2

A geometrically frustrated magnetic CuMnO₂ system has been investigated because of its rich magnetic properties.

Matrix-assisted laser desorption ionization time-of-flight mass spectrometry for the rapid identification of yeasts causing bloodstream infections

Few studies have systematically standardised and evaluated matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) for identification of yeasts from bloodstream infections. This is rapidly becoming pertinent for early identification of yeasts and appropriate antifungal therapy. We used 354 yeast strains identified by polymerase chain reaction (PCR) sequencing for standardisation and 367 blind clinical strains for validation of our MALDI-TOF MS protocols. We also evaluated different sample preparation methods and found the on-plate formic acid extraction method as most cost- and time-efficient. The MALDI-TOF assay correctly identified 98.9% of PCR-sequenced yeasts. Novel main spectrum projections (MSP) were developed for Candida auris, C. viswanathii and Kodamaea ohmeri, which were missing from the Bruker MALDI-TOF MS database. Spectral cut-offs computed by receiver operating characteristics (ROC) analysis showed 99.4% to 100% accuracy at a log score of ≥ 1.70 for C. tropicalis, C. parapsilosis, C. pelliculosa, C. orthopsilosis, C. albicans, C. rugosa, C. guilliermondii, C. lipolytica, C. metapsilosis, C. nivariensis. The differences in the species-specific scores of our standardisation and blind validation strains were not statistically significant, implying the optimal performance of our test protocol. The MSPs of the three new species also were validated. We conclude that MALDI-TOF MS is a rapid, accurate and reliable tool for identification of bloodstream yeasts. With proper standardisation, validation and regular database expansion, its efficiency can be further enhanced.

Processing of Polyetherimide/Cloisite 30B Nanocomposite by Vibration Casting Method

Vibration casting method was developed for making polyetherimide (PEI)/Cloisite 30B nanocomposite. Towards this, a vibration casting apparatus was designed and developed. Vibration casting apparatus provided vibrational energy and heat, simultaneously. The processing parameters were established for vibration casting in terms of frequency of vibration, temperature, time and viscosity of casting mixture. Casting mixture of PEI/Cloisite 30B/N,N-dimethyl acetamide (DMAc) was made by dissolving PEI in DMAc and then mixing Cloisite 30B in this solution. The viscosity of PEI/Cloisite 30B/DMAc mixture was optimized for casting by controlling the volume fraction of PEI in DMAc. Morphology of PEI/Cloisite 30B nanocomposite was examined by wide angle X-ray diffraction, transmission electron microscopy, scanning electron microscopy and contact angle measurement. Mechanical and thermal properties of PEI/Cloisite 30B nanocomposite were also compared with that of neat PEI to ascertain the efficacy of vibration casting method.

Production of extracellular carbohydrases by mushrooms

Seven different mushrooms, in submerged culture, are capable of utilizing various polysaccharides, i.e., xylan, mannan, cellulose, dextran, inulin, added in the medium as sole source of carbon. But chitin was found to be not utilized by any of them. Xylan is commonly utilized by all the mushrooms tested. Inducible and constitutive types of hydrolytic enzymes for those polysaccharides have been identified in the fermented broth of the mushrooms. Xylanase was found to be a constitutive enzyme for most of the strains exceipt for <i>Panaeolus papilionaceus</i> (Bull. ex Fr.) Fr. for which it is inducible.

Effectiveness of radial flow on rewetting of AHWR fuel cluster

Rewetting of a hot surface is the process of establishing direct liquid contact with a large portion of the surface whose initial temperature exceeds that required to maintain film boiling for prescribed surface and flow conditions. The Advanced Heavy water Reactor (AHWR) is a natural circulation vertical pressure tube type boiling light water cooled and heavy water moderated reactor. In case of a loss of coolant accident, the clad surface temperature goes up very high and comes down due to coolant injection from the Emergency Core Coolant System (ECCS). The rewetting takes place in Boiling Water Reactors (BWR) due to top flooding and Pressurised Water Reactors (PWR) due to bottom flooding. But in AHWR, the emergency coolant enters into the reactor core in radial direction and after this, cross flow phenomenon takes place from one fuel pin ring to next. The study is being carried out on the effect of cross flow on rewetting of AHWR fuel bundle. This paper will discuss the modeling of the experimental setup having pressure tube, fuel cluster, steam generator, accumulator etc and study the effect of radial flow on rewetting of fuel pins. An analysis of the model, considering with and without cross flow, has been carried out and shows that the pick fuel temperature is sensitive to cross flow. The thermal hydraulic safety analysis code Relap5/3.2 is being used for modeling of experimental setup for rewetting study.

Experimental study of PHWR debris bed under boil-off condition

Experiments have been carried out to study the heatup behavior of a submerged debris bed constituted of segmented reactor channels of Pressurized Heavy Water Reactors (PHWR). The study has been done for under fully submerged, partially submerged and nearly exposed conditions. This situation may arise from a severe accident scenario of PHWR where full or segmented reactor channels are likely to be disassembled and form a submerged debris bed. An assembly of electrical heater rod, simulating fuel bundle and channel components like Pressure tube and calandria tube constitute each segmented reactor channels. Ten such reactor channels constitute the debris bed. Heatup of this debris bed is observed with respect to different water levels and at power levels of 10, 20 and 30 kW, typical to decay power levels of 0.25 %, 0.5 % and 0.75 % of reactor full power respectively. It has been observed from the set of experiments that fully submerged debris bed does not get heated up and fuel rod temperature remains at saturation temperature. Heatup is observed for exposed channels only, however the heatup rate is limited with steam and radiative cooling. For exposed debris bed, channels surrounded by neighboring channels get heated up as compared to channels at the periphery of the debris bed.

Characterization of groundwater composition in Punjab state with special emphasis on uranium content, speciation and mobility

Groundwaters (borewell and handpump) were sampled from two districts (Bathinda and Mansa) of Punjab state and analyzed for their major ionic concentrations and uranium isotope compositions in order to assess the possible origins of the waters and water–rock interactions that occurred in the deep aquifer system. The major ionic concentrations of waters were plotted on a Piper diagram and grouped into four dominant hydrochemical facies as (Na+K)-SO4+Cl type (69% – 73%), (Ca+Mg)-SO4+Cl type (6% – 21%), (Ca+Mg)–HCO3 type (4% – 6%) and (Na+K)-HCO3 type (2% – 19%). It was observed that mobility of uranium in groundwater was very much influenced by TDS (total dissolved solids). To investigate the various mechanisms for deriving the elevated uranium concentrations in groundwater, 234U/238U activity ratios (ARs) were calculated using the determined activity levels of 234U and 238U. The mean ARs was found to be near unity (i.e. secular equilibrium) in the study regions confirmed that uranium in groundwaters was mainly resulted from its host/parent rocks through weathering processes. The concentration of HCO3 − in ground water showed one order of magnitude higher than the total dissolved SiO2 indicates that carbonate weathering was the dominant process due to major water–rock interaction. The uranium speciation in groundwaters was investigated by an equilibrium model calculation using MEDUSA (make equilibrium diagrams using sophisticated algorithms) under the influence of redox conditions and complexant concentration. At the observed range of pH values, the predominant redox speciation of uranium was observed as hydroxo-carbonato complexes of (UO2)2(CO3)(OH)3 − and hydroxyl complexes of UO2(OH)3 − which might be caused for increasing the solubility of uranium. Due to very low concentration of phosphate in groundwater, its effects on U(VI)-aqueous speciation was negligible.

Spinigerin induces apoptotic like cell death in a caspase independent manner in Leishmania donovani

Antimicrobial peptides (AMPs) are multifunctional components of the innate immune system. Chemotherapeutic agents used for treatment of visceral leishmaniasis (VL) are now threatened due to the emergence of acquired drug resistance and toxicity. AMPs are attractive alternative to conventional pharmaceuticals. In this study, first time we explored the antileishmanial activity of spinigerin originally derived from Pseudacanthotermes spiniger. Leishmania donovani promastigotes present apoptosis-like cell death upon exposure to spinigerin (IC50, 150 μM). The infection rate was reduced by 20% upon exposure to 150 μM spinigerin but no cytotoxicity on host macrophages was observed. Elevation of intracellular ROS level and down-regulation of two ROS detoxifying enzymes, ascorbate peroxidase (APx) and trypanothione reductase (TR) suggested essential role of ROS machinery during spinigerin mediated cell death. About 97% cell population was found to be Annexin-V positive; 44% cells being highly Annexin-V positive. Moreover, we observed morphological changes like cell rounding, nuclear condensation, oligonucleosomal DNA degradation and TUNEL positive cells without loss of membrane integrity upon spinigerin exposure, suggests apoptosis-like death. Interestingly, collapse in mitochondrial membrane potential and increased level of intracellular ROS and calcium were not associated with caspase like activity. Computational analysis suggests spiningerin interacts with trypanothione reductase and thus probably interferes its function to detoxify the toxic ROS level. Therefore, spinigerin induces apoptosis-like cell death in L. donovani in a caspase-independent manner. The study elucidates the antileishmanial property of spinigerin that may be considered for future chemotherapeutic option alone or adjunct with other drug regimens for improved treatment of visceral leishmaniasis.

Analytical study on degraded core quenching

Severe accident analysis of a reactor helps in emergency planning and evolution of Severe Accident Management Guidelines (SAMG). Actions recommended in the SAMG aim at arresting accident progression and limiting significant radioactive release. However, success of these SAMG actions needs to be assessed with respect to the evolution of accident. Analysis of consequences of injection of water into the reactor pressure vessel from bottom only as a SAMG action has been carried out for VVER-1000 (V320) reactor. The analysis shows that the success of this SAMG action depends not only on the state of core degradation at the time of injection, but also on the highest temperature reached in the reactor core at the time of injection as well as the availability of steam in the RPV.

Processing of ABS Latex in a Single Screw Extruder

The feasibility of the continuous and direct conversion from latex to wet crumb through the coagulation process in an extruder has been demonstrated through this work. The coagulation efficiency in the extruder has been largely governed by temperature. The maximum rate of increase of the first and the second moments of the particle size distribution of the coagulated latex occur in the neighborhood of the polymer glass transition temperature. The particle densities showed no longer a one-to-one relationship to the specific surface typical of the batch coagulation experiments, as the material coagulated in the extruder did not reach the same degree of equilibrium. Although the basic trends remained the same as in the batch coagulation experiments, the addition of residence time distribution, inherently associated with the extruder operation, introduced some significant changes into the coagulation process.

Heat transfer study of a submerged reactor channel under boil-off condition

Experiments have been carried out to study the heatup behavior of a single segmented reactor channel for Pressurized Heavy Water Reactor under submerged, partially submerged and exposed conditions. This situation may arise from a severe accident scenario of Pressurised Heavy Water Reactors where full or segmented reactor channels are likely to be disassembled and form a submerged debris bed. An assembly of electrical heater rod, simulating fuel bundle and channel components like Pressure Tube and Calandria Tube constitutes the segmented reactor channel. Heatup of this assembly is observed with respect to different water levels ranging from full submergence to totally exposed and power levels of 6–8 kW, typical to decay power level. It has been observed from the set of experiment that fuel bundle local dry out followed by heatup does not happen till the bundle is partially submerged. Temperature excursion of the bundle is evident when the bundle is exposed to steam-air environment.

Preliminary evaluation of effect of Engineered Safety Features on source term for AHWR containment

The proposed Advanced Heavy Water Reactor (AHWR) employs double containment envelope along with many Engineered Safety Features (ESFs) to mitigate the consequences of Loss-of-Coolant Accidents (LOCA) with safety system failure, during which high enthalpy steam and radioactive fission products will be discharged into the containment. In such conditions, the pressurized containment will be the source of activity release to the environment by way of leakage. It is required to study the effect of ESFs on the source term from the AHWR containment. An analysis was performed to evaluate the release rate from the AHWR containment during a postulated accident with the in-house containment code CONTRAN and the aerosol behavior code NAUA5-M in a coupled way. Modules for simulating the engineered safety features were incorporated in the CONTRAN code and the aerosol transport behaviour was evaluated using NAUA5-M separately. The AHWR containment is divided into three nodal volumes interconnected by junctions. The blow down mass, energy discharge data and activity released into the containment from the reactor core, for a postulated LOCA case of 200% RIH break with failure of shutdown systems (1 & 2), are inputs to the CONTRAN code. Thermodynamic parameters like containment gas temperature, partial pressure of steam, air in the subdivided volumes along with the flow rates through junctions obtained from CONTRAN were supplied to NAUA5-M. An analysis was carried out for a number of cases, postulated based on availability/unavailability of ESFs. Pressure, temperature and activity concentration transients were evaluated, for 72 h, in the subdivided volumes along with the activity released out of the containment through leakages and stack discharges for all the cases. This paper highlights the importance of operation of ESF in reducing the activity release to the environment.

Simulation model of a nuclear power plant turbine

A computer code “TURDYN” has been developed for prediction of high pressure and low pressure turbine torque under thermodynamic transient conditions. The model is based on the conservation laws of mass and energy. All the important components of turbine systems, e. g. high pressure turbine, low pressure turbine, feed heaters, reheater, moisture separator have been considered. The dynamic equations are solved simultaneously to obtain the stage pressure at various load conditions. The details of the mathematical formulation of the model and open loop responses for specific disturbances are presented.