Large magnetic gap at the Dirac point in Bi2Te3/MnBi2Te4 heterostructures.

Magnetically doped topological insulators enable the quantum anomalous Hall effect (QAHE), which provides quantized edge states for lossless charge-transport applications1-8. The edge states are hosted by a magnetic energy gap at the Dirac point2, but hitherto all attempts to observe this gap directly have been unsuccessful. Observing the gap is considered to be essential to overcoming the limitations of the QAHE, which so far occurs only at temperatures that are one to two orders of magnitude below the ferromagnetic Curie temperature, TC (ref. 8). Here we use low-temperature photoelectron spectroscopy to unambiguously reveal the magnetic gap of Mn-doped Bi2Te3, which displays ferromagnetic out-of-plane spin texture and opens up only below TC. Surprisingly, our analysis reveals large gap sizes at 1 kelvin of up to 90 millielectronvolts, which is five times larger than theoretically predicted9. Using multiscale analysis we show that this enhancement is due to a remarkable structure modification induced by Mn doping: instead of a disordered impurity system, a self-organized alternating sequence of MnBi2Te4 septuple and Bi2Te3 quintuple layers is formed. This enhances the wavefunction overlap and size of the magnetic gap10. Mn-doped Bi2Se3 (ref. 11) and Mn-doped Sb2Te3 form similar heterostructures, but for Bi2Se3 only a nonmagnetic gap is formed and the magnetization is in the surface plane. This is explained by the smaller spin-orbit interaction by comparison with Mn-doped Bi2Te3. Our findings provide insights that will be crucial in pushing lossless transport in topological insulators towards room-temperature applications.

Comparative assessment of climate resilient potential in four poultry genotypes reared in hot-humid tropical environment: a preliminary evaluation.

The general objective of this study is to comparatively assess the climate-resilient potential of four different poultry genotypes-Giriraja (n = 8), Country chicken (n = 8), Naked neck (n = 8), and Kadaknath (n = 8)-reared in a hot-humid tropical environment. Birds from all genotypes had ad libitum access to feed and water and were exposed to identical environmental temperatures in the experimental shed. Diurnal meteorological data were recorded inside and outside the shed daily. Blood biochemical, hormonal, and endocrine variables were monitored monthly until the birds reached 12 weeks of age. Significant variations (P < 0.01) were observed at different intervals in variables, including total protein, albumin, globulin, triglycerides, and cholesterol. Genotype-specific differences were noted in triglycerides (P < 0.01), albumin (P < 0.01), total protein (P < 0.05), and cholesterol (P < 0.05). Inter-genotype variations (P < 0.05) were also observed in serum cortisol, T3, and T4 levels. Distinct variations (P < 0.05) were also observed during specific intervals, particularly in cortisol and T3 levels. The study of hepatic mRNA expression of HSPs and HSF-1 revealed a significant breed difference (P < 0.05) in the expression pattern of HSP60, HSP70, HSP90, and HSP110, while no difference was observed between genotypes for HSP40 and HSF-1. The study highlights the Naked Neck breed as an exemplar of resilience, showcasing its distinctive ability to maintain homeostasis under heat stress compared to other genotypes. The genetic and physiological insights gained from this investigation offer prospective pathways for aligning sustainable poultry farming with environmental exigencies.

Comparative assessment of growth performance, heat resistance and carcass traits in four poultry genotypes reared in hot-humid tropical environment.

This study investigated the impact of heat stress on growth and carcass traits in four poultry genotypes-Giriraja, Country chicken, Naked Neck and Kadaknath reared in a hot and humid tropical environment. Birds from all genotypes had ad libitum access to feed and water while being challenged with consistently high environmental temperatures in the experimental shed. Daily diurnal meteorological data were recorded inside and outside the shed. The study specifically examined growth variables and carcass characteristics. Significant differences (p < 0.01) were observed in body weight and average daily gain at various intervals. Notably, feed intake showed significant differences (p < 0.01) across weeks, indicating interactions between genotypes and time intervals. The feed conversion ratio (FCR) varied significantly (p < 0.01), with the highest FCR recorded in the Kadaknath breed. Livability percentages were similar across groups, except for Giriraja, which had significantly lower livability (p < 0.01). Carcass traits, including dressing, wings, feathers and giblet percentages, showed significant differences among genotypes (p < 0.01). Hepatic mRNA expression of growth-related genes revealed numerical variations, with Naked Neck displaying the highest (p < 0.05) fold change in IGF-1 expression compared to other genotypes. The study recognized in the Naked Neck genotype to possess higher resilience in maintaining homoeostasis and uncompromised growth under heat stress, providing valuable insights for sustainable poultry farming in challenging environmental conditions.

Accelerated discovery of two crystal structure types in a complex inorganic phase field.

The discovery of new materials is hampered by the lack of efficient approaches to the exploration of both the large number of possible elemental compositions for such materials, and of the candidate structures at each composition. For example, the discovery of inorganic extended solid structures has relied on knowledge of crystal chemistry coupled with time-consuming materials synthesis with systematically varied elemental ratios. Computational methods have been developed to guide synthesis by predicting structures at specific compositions and predicting compositions for known crystal structures, with notable successes. However, the challenge of finding qualitatively new, experimentally realizable compounds, with crystal structures where the unit cell and the atom positions within it differ from known structures, remains for compositionally complex systems. Many valuable properties arise from substitution into known crystal structures, but materials discovery using this approach alone risks both missing best-in-class performance and attempting design with incomplete knowledge. Here we report the experimental discovery of two structure types by computational identification of the region of a complex inorganic phase field that contains them. This is achieved by computing probe structures that capture the chemical and structural diversity of the system and whose energies can be ranked against combinations of currently known materials. Subsequent experimental exploration of the lowest-energy regions of the computed phase diagram affords two materials with previously unreported crystal structures featuring unusual structural motifs. This approach will accelerate the systematic discovery of new materials in complex compositional spaces by efficiently guiding synthesis and enhancing the predictive power of the computational tools through expansion of the knowledge base underpinning them.

Anomalous quantum criticality in the electron-doped cuprates.

In the physics of condensed matter, quantum critical phenomena and unconventional superconductivity are two major themes. In electron-doped cuprates, the low critical field (HC2) allows one to study the putative quantum critical point (QCP) at low temperature and to understand its connection to the long-standing problem of the origin of the high-TC superconductivity. Here we present measurements of the low-temperature normal-state thermopower (S) of the electron-doped cuprate superconductor La2-x Ce x CuO4 (LCCO) from x = 0.11-0.19. We observe quantum critical [Formula: see text] versus [Formula: see text] behavior over an unexpectedly wide doping range x = 0.15-0.17 above the QCP (x = 0.14), with a slope that scales monotonically with the superconducting transition temperature (TC with H = 0). The presence of quantum criticality over a wide doping range provides a window on the criticality. The thermopower behavior also suggests that the critical fluctuations are linked with TC Above the superconductivity dome, at x = 0.19, a conventional Fermi-liquid [Formula: see text] behavior is found for [Formula: see text] 40 K.

Designing switchable polarization and magnetization at room temperature in an oxide.

Ferroelectric and ferromagnetic materials exhibit long-range order of atomic-scale electric or magnetic dipoles that can be switched by applying an appropriate electric or magnetic field, respectively. Both switching phenomena form the basis of non-volatile random access memory, but in the ferroelectric case, this involves destructive electrical reading and in the magnetic case, a high writing energy is required. In principle, low-power and high-density information storage that combines fast electrical writing and magnetic reading can be realized with magnetoelectric multiferroic materials. These materials not only simultaneously display ferroelectricity and ferromagnetism, but also enable magnetic moments to be induced by an external electric field, or electric polarization by a magnetic field. However, synthesizing bulk materials with both long-range orders at room temperature in a single crystalline structure is challenging because conventional ferroelectricity requires closed-shell d(0) or s(2) cations, whereas ferromagnetic order requires open-shell d(n) configurations with unpaired electrons. These opposing requirements pose considerable difficulties for atomic-scale design strategies such as magnetic ion substitution into ferroelectrics. One material that exhibits both ferroelectric and magnetic order is BiFeO3, but its cycloidal magnetic structure precludes bulk magnetization and linear magnetoelectric coupling. A solid solution of a ferroelectric and a spin-glass perovskite combines switchable polarization with glassy magnetization, although it lacks long-range magnetic order. Crystal engineering of a layered perovskite has recently resulted in room-temperature polar ferromagnets, but the electrical polarization has not been switchable. Here we combine ferroelectricity and ferromagnetism at room temperature in a bulk perovskite oxide, by constructing a percolating network of magnetic ions with strong superexchange interactions within a structural scaffold exhibiting polar lattice symmetries at a morphotropic phase boundary (the compositional boundary between two polar phases with different polarization directions, exemplified by the PbZrO3-PbTiO3 system) that both enhances polarization switching and permits canting of the ordered magnetic moments. We expect this strategy to allow the generation of a range of tunable multiferroic materials.

Assessment of Prescribing Pattern and Safety Profile of Drugs Used in Intranasal Route in Paediatric Age Group of Patients in a Tertiary Care Hospital.

Background Recently there has been an increased preference for intranasal delivery of drugs due to highly vascular nasal mucosa, bypassing first pass metabolism and the blood brain barrier (BBB) lead in quick drug absorption to the systemic circulation and direct access to brain from olfactory region. For pediatric patients this route offers significant benefits over injections or oral routes, like increased compliance, easy administration, and minimal side effects. Objective Assessment of prescription pattern of drugs and safety profile of drugs used by intranasal route in paediatric age group. Method Our study was a prospective observational study paediatric age group of patients conducted in the departments of Pharmacology, Paediatrics and Otorhinolaryngology of Burdwan Medical College and Hospital, Burdwan. Data were collected in CRF and frequency distribution of collected data done. Microsoft Excel 2010 was used for analysis. Result Common age group was infants. Males were more in number. Most common indication was epistaxis. Intranasal drugs per prescription were 1.05. Most commonly prescribed intranasal drug was nasal saline. Nasal decongestant was the most common prescribed medication. Nasal drops were the most common dose formulation. Conclusion Intranasal drug prescribing in our study was mainly aimed for treating local problems, very few being for systemic action. Some prescribing indicators like prescribing by generic name and prescribing from national essential drug lists were acceptable with scope for improvement. Average number of drugs per prescription and antibiotic use was high. Adverse events after intranasal drug use were primarily local and nose related.

An Open Label Prospective Study on Evaluation of Safety and Efficacy of Cilnidipine Over Amlodipine in Stage 1 Hypertensive Patients.

Background Calcium channel blockers are considered the first line drug over renin-angiotensinaldosterone system inhibitor in black population and with renin-angiotensinaldosterone system inhibitor in non-black population with Hypertension. Amlodipine has longer biological half life and lower potential to stimulate SNS. But, is associated with reflex tachycardia and pedal oedema. Cilnidipine has potent inhibitory both on voltage gated L-type and N-type calcium channels with better anti-proteinuric effect and good tolerability. Hence, our study compared the efficacy, safety and compliance of cilnidipine over amlodipine in Stage 1 hypertensive subjects. Objective To find out antihypertensive and renoprotective effect of cilnidipine. Method The study was open-label, single centre, prospective, parallel design, randomized controlled was done in Outdoor Patient Department (OPD) of Medicine and Department of Pharmacology in Burdwan Medical College and Hospital (BMCH). Patients with stage 1 HTN received cilnidipine while the other group received amlodipine. There were 4 follow-up visits for each participant consisting of baseline, 1 week, 6 weeks and after 12 weeks. Clinical parameters including pulse rate, blood pressure and ankle oedema noted also laboratory investigations were done. Safety parameters with adverse events and compliance by traditional pill count method. Result Blood pressure was effectively decreased by both amlodipine and cilnidipine. Cilnidipine significantly decreased Pulse Rate while amlodipine increased it and the difference in Pulse Rate comparing both the groups was statistically significant. None of the ADRs were statistically significant except pedal oedema. Pedal oedema was noted only in amlodipine arm and was statistically significant. Compliance to both the drugs was excellent. Total cost of therapy was higher with cilnidipine. Conclusion Though amlodipine is preferred drug, cilnidipine should be a better alternative when we consider subjects with sympathetic over activity, proteinuria or pedal oedema.

Negative Longitudinal Magnetoresistance from the Anomalous N=0 Landau Level in Topological Materials.

Negative longitudinal magnetoresistance (NLMR) is shown to occur in topological materials in the extreme quantum limit, when a magnetic field is applied parallel to the excitation current. We perform pulsed and dc field measurements on Pb_{1-x}Sn_{x}Se epilayers where the topological state can be chemically tuned. The NLMR is observed in the topological state, but is suppressed and becomes positive when the system becomes trivial. In a topological material, the lowest N=0 conduction Landau level disperses down in energy as a function of increasing magnetic field, while the N=0 valence Landau level disperses upwards. This anomalous behavior is shown to be responsible for the observed NLMR. Our work provides an explanation of the outstanding question of NLMR in topological insulators and establishes this effect as a possible hallmark of bulk conduction in topological matter.

Effects of ionic liquids on the nanoscopic dynamics and phase behaviour of a phosphatidylcholine membrane.

Ionic liquids (ILs) are potential candidates for new antimicrobials due to their tunable antibacterial and antifungal properties that are required to keep pace with the growing challenge of bacterial resistance. To a great extent their antimicrobial actions are related to the interactions of ILs with cell membranes. Here, we report the effects of ILs on the nanoscopic dynamics and phase behaviour of a dimyristoylphosphatidylcholine (DMPC) membrane, a model cell membrane, as studied using neutron scattering techniques. Two prototypical imidazolium-based ILs 1-butyl-3-methylimidazolium tetrafluoroborate (BMIM[BF4]) and 1-decyl-3-methylimidazolium tetrafluoroborate (DMIM[BF4]), which differ only in terms of the alkyl chain length of cations, have been used for the present study. Fixed Elastic Window Scan (FEWS) shows that the incorporation of ILs affects the phase behaviour of the phospholipid membrane significantly and the transition from a solid gel to a fluid phase shifts to lower temperature. This is found to be consistent with our differential scanning calorimetry measurements. DMIM[BF4], which has a longer alkyl chain cation, affects the phase behaviour more strongly in comparison to BMIM[BF4]. The pressure-area isotherms of the DMPC monolayer measured at the air-water interface show that in the presence of ILs, isotherms shift towards higher area-per lipid molecule. DMIM[BF4] is found to shift the isotherm to a greater extent compared to BMIM[BF4]. Quasielastic neutron scattering (QENS) data show that both ILs act as a plasticizer, which enhances the fluidity of the membrane. DMIM[BF4] is found to be a stronger plasticizing agent in comparison to BMIM[BF4] that has a cation with a shorter alkyl chain. The incorporation of DMIM[BF4] enhances not only the long range lateral motion but also the localised internal motion of the lipids. On the other hand, BMIM[BF4] acts weakly in comparison to DMIM[BF4] and mainly alters the localised internal motion of the lipids. Any subtle change in the dynamical properties of the membrane can profoundly affect the stability of the cell. Hence, the dominant effect of the IL with the longer chain length on the dynamics of the phospholipid membrane might be correlated with its cytotoxic activity. QENS data analysis has provided a quantitative description of the effects of the two imidazolium-based ILs on the dynamical and phase behaviour of the model cell membrane, which is essential for a detailed understanding of their action mechanism.

Jahn-Teller effect in LiMn2O4: influence on charge ordering, magnetoresistance and battery performance.

The phase transition near room temperature in LiMn2O4 was studied using thermal expansion measurements, and directly compared with the electrochemical performance of the material. Studies based on thermal expansion indicate the onset of a first-order phase transition at Tc ∼ 220 K for the nearly half-doped material, with [Mn3+]/[Mn4+] ≈ 1. The Tc shifts to a higher temperature, ∼290 K, and signatures for Verwey-type charge ordering at 290 K can be observed when the fraction of Jahn-Teller Mn3+ in LiMn2O4 is increased, i.e., [Mn3+]/[Mn4+] > 1. These studies show that the first-order phase transition near room temperature in LiMn2O4 is associated with charge ordering, which ultimately is a consequence of the Jahn-Teller effect. In addition, the Jahn-Teller effect is proven to be an important cause of magnetoresistance and electrochemical capacity fading in LiMn2O4. Electrochemical measurements show that both materials, either with a Tc ∼ 220 K or Tc ∼ 290 K, exhibit capacity fading to almost the same extent. Electrochemical capacity retention is observed only in nanosized LiMn2O4, for which the phase transition anomalies are completely absent.

Efficacy of leaves (drumstick, mint and curry leaves) powder as natural preservatives in restructured chicken block.

The use of natural preservatives to increase the shelf-life of meat products is promising as they possess antioxidant and antimicrobial properties. Earlier, a highly acceptable restructured chicken slice without the addition of extra fat was developed in the same laboratory which was acceptable up to 10th day of storage under refrigeration and spoilage was mainly due to oxidation. Hence, the present study was planned to determine the efficacy of certain plant leaves' (drumstick, mint and curry leaves) powder at 1 % level as natural preservatives to enhance the shelf life of restructured chicken slices under refrigerated storage. The quality attributes of the products containing different natural preservativs were compared with the control and reference products. The control product contained no preservative and the reference product contained BHT (200 ppm) only. Incorporation of the leaf powders at 1 % level did not show any significant differences for both cooking yield (99.5-99.6 %) and proximate composition (moisture 72.2-72.3 %, protein 19.2-19.4 %, fat 4.2-4.3 % and total ash 2.3-2.4 %) of the restructured chicken slices compared to both control and reference products during storage. All products containing leaf powders showed significantly (P < 0.01) lower microbial counts (2.9-3.7 log10 CFU/g) compared to both control and BHT added products. Yeast and mould were not detected in any of the products throughout the storage period. Sensory evaluation scores showed that the restructured chicken slices incorporated with the leaf powders were as acceptable as the reference product and rated good to very good for appearance, flavor, juiciness and overall acceptability. Restructured chicken slices with the leaf powders could be safely stored without much loss in quality up to 20 days under refrigeration.

Expression, purification, crystallization and preliminary X-ray diffraction analysis of carbonyl reductase from Candida parapsilosis ATCC 7330.

The NAD(P)H-dependent carbonyl reductase from Candida parapsilosis ATCC 7330 catalyses the asymmetric reduction of ethyl 4-phenyl-2-oxobutanoate to ethyl (R)-4-phenyl-2-hydroxybutanoate, a precursor of angiotensin-converting enzyme inhibitors such as Cilazapril and Benazepril. The carbonyl reductase was expressed in Escherichia coli and purified by GST-affinity and size-exclusion chromatography. Crystals were obtained by the hanging-drop vapour-diffusion method and diffracted to 1.86 Šresolution. The asymmetric unit contained two molecules of carbonyl reductase, with a solvent content of 48%. The structure was solved by molecular replacement using cinnamyl alcohol dehydrogenase from Saccharomyces cerevisiae as a search model.

A rationale for the rapid extraction of ultra-low-level uranyl ions in simulated bioassays regulated by Mn-dopants over magnetic nanoparticles.

Although the sorption of uranyl ions and other heavy metal ions over magnetic nanoparticles is well reported, the parameters governing the sorption process over the magnetic nanoparticles have not been clearly enumerated. However, to increase the efficiency of the sorption over the surface of these magnetic nanoparticles, it is essential to understand the different structural parameters that are involved in the sorption process. The sorption of uranyl ions and other competitive ions in simulated urine samples at different pH was effectively accomplished over magnetic nanoparticles of Fe3O4 (MNPs) and Mn-doped Fe3O4 (Mn-MNPs). The MNPs and Mn-MNPs were synthesized using an easily modified co-precipitation method and were thoroughly characterised using several techniques, such as XRD, HRTEM, SEM, zeta potential, and XPS. The substitutional doping of Mn (1 to 5 at%) in the Fe3O4 lattice (Mn-MNPs) showed better sorption ability as compared to that of MNPs. The sorption properties of these nanoparticles were mainly correlated with the different structural parameters to understand the roles of surface charge and different morphological parameters. The interaction centres over the surface of MNPs with the uranyl ions were designated and the effects of ionic interactions with uranyl ions for these sites were calculated. Extensive XPS, ab initio calculations and zeta potential studies have provided deep insights into the different aspects that play key roles in the sorption process. These materials showed one of the best Kd values (∼3 × 106 cm3) in a neutral medium with very low t1/2 values (∼0.9 min). The fast sorption kinetics (very low t1/2) makes them amongst the best sorption materials for uranyl ions and optimal for the quantification of ultra-low-level uranyl ions in simulated bioassays.

Near-room-temperature colossal magnetodielectricity and multiglass properties in partially disordered La2NiMnO6.

We report magnetic, dielectric, and magnetodielectric responses of the pure monoclinic bulk phase of partially disordered La2NiMnO6, exhibiting a spectrum of unusual properties and establish that this compound is an intrinsically multiglass system with a large magnetodielectric coupling (8%-20%) over a wide range of temperatures (150-300 K). Specifically, our results establish a unique way to obtain colossal magnetodielectricity, independent of any striction effects, by engineering the asymmetric hopping contribution to the dielectric constant via the tuning of the relative-spin orientations between neighboring magnetic ions in a transition-metal oxide system. We discuss the role of antisite (Ni-Mn) disorder in emergence of these unusual properties.

Interactions of Mn2+ with a non-self-complementary Z-type DNA duplex.

Crystal structures of the hexanucleotide d(CACGCG)·d(CGCGTG) were determined in two crystal lattices when different concentrations of the counterion Mn2+ were used in crystallization. The availability of Mn2+ during the crystallization process appears to play an important role in inducing different crystal packings that lead to crystals belonging to the two space groups P2(1) and P6(5). Analysis of the molecular interactions of Mn2+ with the Z-form duplexes shows direct coordination to the purine residues G and A.

Opportunities to prevent and manage undernutrition to amplify efforts to end TB.

The bidirectional relationship between TB and nutrition is well recognized - primary undernutrition is a risk factor for developing TB disease, while TB results in wasting. Although nutrition support is acknowledged as an important intervention in TB programmes, it is seldom afforded commensurate priority for action. TB incidence and deaths worldwide are falling too slowly to meet WHO End TB Strategy milestones, and the number of undernourished people is increasing, likely to be further exacerbated by the ongoing COVID-19 pandemic. Undernutrition needs to be more urgently and intensively addressed. This is especially true for the WHO South-East Asia Region, where the high rates of undernutrition are a key driver of the TB epidemic. The evidence base has been sufficiently robust for clear and workable programmatic guidance to be formulated on assessment, counselling and interventions for TB patients. Many high-burden countries have developed policies addressing TB and nutrition. Gaps in research to date have frustrated the development of more refined programmatic approaches related to addressing TB and malnutrition. Future research can be shaped to inform targeted, actionable policies and programmes delivering dual benefits in terms of undernutrition and TB. There are clear opportunities for policy-makers to amplify efforts to end TB by addressing undernutrition.

The sequence d(CGGCGGCCGC) self-assembles into a two dimensional rhombic DNA lattice.

We report here the crystal structure of the partially self-complementary decameric sequence d(CGGCGGCCGC), which self assembles to form a four-way junction with sticky ends. Each junction binds to four others through Watson-Crick base pairing at the sticky ends to form a rhombic structure. The rhombuses bind to each other and form two dimensional tiles. The tiles stack to form the crystal. The crystal diffracted in the space group P1 to a resolution of 2.5Å. The junction has the anti-parallel stacked-X conformation like other junction structures, though the formation of the rhombic net noticeably alters the details of the junction geometry.

The structure of a full turn of an A-DNA duplex d(CGCGGGTACCCGCG)2.

We report the 2.6Å resolution crystal structure of the tetra-decamer d(CGCGGGTACCCGCG) in the tetragonal space group P43. This sequence contains the KpnI restriction site GGTACC in the centre which is flanked by alternating 'CG' sequences, and has a 'TA' step at the centre. These are features could favour the left-handed Z type helix. Despite this, overall the molecule has the A form. This is the first tetra-decamer crystallized in the A-DNA conformation, i.e. more than one full turn of the A helix. The crystallographic asymmetric unit consists of one tetra-decamer duplex. The helical twist and slide, as well as the base pair-base pair stacking interactions show alternations at the alternating pyrimidine-purine and purine-pyrimidine base steps. This variation is reminiscent of the dinucleotide repeat in left-handed Z-DNA helices. The crystal packing is unlike other A-DNA crystal structures, with each helix having a large number of contacts of many different types with symmetry-related neighbours.