Comprehensive first principles to investigate optoelectronic and transport phenomenon of lead-free double perovskites Ba2AsBO6 (B[bond, double bond]Nb, Ta) compounds

In the current work we studied the structural, elastics, electrical, optical, thermoelectric, as well as spectroscopic limited maximum efficiency (SLME) of oxide based Ba2AsBO6 (B[bond, double bond]Nb, Ta) materials. All the calculations were performed using first-principles calculation by employing the WIEN2k code. We checked the stability in diverse forms such as optimization, phonon dispersion, mechanical, formation energy, cohesive energy, and thermal stability is computed. The semiconducting nature of these Ba2AsBO6 (B[bond, double bond]Nb, Ta) systems is revealed by calculating the direct band gap values are 1.97 eV and 1.49 eV respectively. Additionally, we determined the optical properties which analyze the utmost absorption and transition of carriers versus photon energy (eV). Moreover, Ba2AsNbO6 has an estimated SLME of 32 %, making it an encouraging alternative for single-junction solar cells. Lastly, we studied the transport properties against temperature, the chemical potential for p-type and n-type charge carriers at various temperatures. At 300 K, the zT values are found to be 0.757 and 0.751 for Ba2AsBO6 (B[bond, double bond]Nb, Ta) compounds respectively. Both materials were examined as having strong absorption patterns and an excellent figure of merit (ZT), indicating that materials are appropriate for daily life applications.

Emergence of Long-Range Angular Correlations in Low-Multiplicity Proton-Proton Collisions

This Letter presents the measurement of near-side associated per-trigger yields, denoted ridge yields, from the analysis of angular correlations of charged hadrons in proton-proton collisions at sqrt[s]=13  TeV. Long-range ridge yields are extracted for pairs of charged particles with a pseudorapidity difference of 1.4<|Δη|<1.8 and a transverse momentum of 1 Collapse

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First Measurement of the |t| Dependence of Incoherent J/ψ Photonuclear Production

The first measurement of the cross section for incoherent photonuclear production of J/ψ vector mesons as a function of the Mandelstam |t| variable is presented. The measurement was carried out with the ALICE detector at midrapidity, |y|<0.8, using ultraperipheral collisions of Pb nuclei at a center-of-mass energy per nucleon pair of sqrt[s_{NN}]=5.02  TeV. This rapidity interval corresponds to a Bjorken-x range (0.3-1.4)×10^{-3}. Cross sections are given in five |t| intervals in the range 0.04<|t|<1  GeV^{2} and compared to the predictions by different models. Models that ignore quantum fluctuations of the gluon density in the colliding hadron predict a |t| dependence of the cross section much steeper than in data. The inclusion of such fluctuations in the same models provides a better description of the data.

ψ(2S) Suppression in Pb-Pb Collisions at the LHC

The production of the ψ(2S) charmonium state was measured with ALICE in Pb-Pb collisions at sqrt[s_{NN}]=5.02  TeV, in the dimuon decay channel. A significant signal was observed for the first time at LHC energies down to zero transverse momentum, at forward rapidity (2.5 Collapse

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Exploring the mechanical, vibrational optoelectronic, and thermoelectric properties of novel half-Heusler FeTaX (X = P, As): a first-principles study

In this study, the density functional theory (DFT) was employed to study the structural, electronic, optical, and thermoelectric characteristics of half-Heusler (HH) FeTaX (X = P or As). Optimization of the structures was achieved using Perdew-Burke-Ernzerhof (PBE) parametrized generalized gradient approximation (GGA). These HH FeTaX (X = P, As) showed indirect bandgaps of 0.882 eV and 0.748 eV, respectively. The predicted density of states (DOS) spectra suggest that Fe-d and Ta-d states contribute predominantly to both valence and conduction bands, whereas P/As-p states contribute less. Optical properties were investigated to assess their potential in optoelectronic applications. The estimated values of various optical parameters and low loss suggest that the studied HH FeTaX (X = P, As) are suitable for optoelectronic device applications. The thermoelectric responses of the studied HH FeTaX (X = P, As) were computed, and their highest power factors at high temperature reflects their usage in thermoelectric devices.

Study of mechanical, optical, and thermoelectric characteristics of Ba2 XMoO6 (X = Zn, Cd) double perovskite for energy harvesting

The double perovskites are become the emerging aspirant to fulfill the demand of energy. Therefore, the optoelectronic, elastic and transport characteristics of Ba2 XMoO6 (X = Zn, Cd) are addressed systemically. The elastic constants show the mechanical stability. The nature of Ba2 ZnMoO6 is brittle and Ba2 CdMoO6 is ductile with large values of Debye temperature covalent bonding. The electronic band structures exhibit band gaps of 2.81 and 2.98 eV, which increase their importance for optoelectronic applications. The absorption of light energy, optical loss, refractive index, polarization of light energy are addressed in the energy range zero to 14 eV. Furthermore, thermoelectric characteristics are computed against chemical potentials at 300, 600, and 900 K. The chemical potential decides the p-type nature, with holes as majority carriers. The increasing temperature increases the power factor and figure of merit. Therefore, the optoelectronic and thermoelectric characteristics reveals the importance of studied DPs for energy applications.

Measurements of Groomed-Jet Substructure of Charm Jets Tagged by D^{0} Mesons in Proton-Proton Collisions at sqrt[s]=13 TeV

Understanding the role of parton mass and Casimir color factors in the quantum chromodynamics parton shower represents an important step in characterizing the emission properties of heavy quarks. Recent experimental advances in jet substructure techniques have provided the opportunity to isolate and characterize gluon emissions from heavy quarks. In this Letter, the first direct experimental constraint on the charm-quark splitting function is presented, obtained via the measurement of the groomed shared momentum fraction of the first splitting in charm jets, tagged by a reconstructed D^{0} meson. The measurement is made in proton-proton collisions at sqrt[s]=13  TeV, in the low jet transverse-momentum interval of 15≤p_{T}^{jet ch}<30  GeV/c where the emission properties are sensitive to parton mass effects. In addition, the opening angle of the first perturbative emission of the charm quark, as well as the number of perturbative emissions it undergoes, is reported. Comparisons to measurements of an inclusive-jet sample show a steeper splitting function for charm quarks compared with gluons and light quarks. Charm quarks also undergo fewer perturbative emissions in the parton shower, with a reduced probability of large-angle emissions.

Theoretical insights into the structural, optoelectronic, thermoelectric, and thermodynamic behavior of novel quaternary LiZrCoX (X = Ge, Sn) compounds based on first-principles study

The structural, magnetic, electronic, elastic, vibrational, optical, thermodynamic as well as thermoelectric properties of newly predicted quaternary LiZrCoX (X = Ge, Sn) Heusler compounds are evaluated intricately with the aid of ab initio techniques developed under the framework of density functional theory. The computed structural properties are found to be in tandem with the existing analogous theoretical and experimental facts. Structural optimization has been carried out in three different structural arrangements, i.e., Type-1, Type-2, and Type-3. Further analysis of the optimization curves reveals that the Type-3 phase, which has the least amount of energy, is the most stable structure for the compounds under consideration. The tabulated cohesive energy and formation energy of these compounds depict their chemical as well as thermodynamic stability. The absence of negative phonon frequencies in the phonon band spectrum of the studied compounds depicts their dynamic stability. Similarly, the tabulated second-order elastic constants (Cij) and the linked elastic moduli show their stability in the cubic phase. The calculated value of Pugh's ratio and Cauchy pressure reveal that LiZrCoGe is brittle whereas LiZrCoSn is ductile. Additionally, the optical characteristics of the compounds are studied in terms of the dielectric function, refractive index, extinction coefficient, absorption coefficient, reflectivity, energy loss function, and optical conductivity. The obtained high value of power factor and figure of merit of the studied lithium-based quaternary compounds predict good thermoelectric behavior in these compounds. Thus, LiZrCoX (X = Ge, Sn) compounds can therefore be used to create innovative and intriguing thermoelectric materials as well as optoelectronic and energy-harvesting equipment.

Measurement of the Lifetime and Λ Separation Energy of _{Λ}^{3}H

The most precise measurements to date of the _{Λ}^{3}H lifetime τ and Λ separation energy B_{Λ} are obtained using the data sample of Pb-Pb collisions at sqrt[s_{NN}]=5.02  TeV collected by ALICE at the LHC. The _{Λ}^{3}H is reconstructed via its charged two-body mesonic decay channel (_{Λ}^{3}H→^{3}He+π^{-} and the charge-conjugate process). The measured values τ=[253±11(stat)±6(syst)]  ps and B_{Λ}=[102±63(stat)±67(syst)]  keV are compatible with predictions from effective field theories and confirm that the _{Λ}^{3}H structure is consistent with a weakly bound system.

Measurement of the J/ψ Polarization with Respect to the Event Plane in Pb-Pb Collisions at the LHC

We study the polarization of inclusive J/ψ produced in Pb-Pb collisions at sqrt[s_{NN}]=5.02  TeV at the LHC in the dimuon channel, via the measurement of the angular distribution of its decay products. We perform the study in the rapidity region 2.5 Collapse

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First Measurement of Antideuteron Number Fluctuations at Energies Available at the Large Hadron Collider

The first measurement of event-by-event antideuteron number fluctuations in high energy heavy-ion collisions is presented. The measurements are carried out at midrapidity (|η|<0.8) as a function of collision centrality in Pb-Pb collisions at sqrt[s_{NN}]=5.02  TeV using the ALICE detector. A significant negative correlation between the produced antiprotons and antideuterons is observed in all collision centralities. The results are compared with a state-of-the-art coalescence calculation. While it describes the ratio of higher order cumulants of the antideuteron multiplicity distribution, it fails to describe quantitatively the magnitude of the correlation between antiproton and antideuteron production. On the other hand, thermal-statistical model calculations describe all the measured observables within uncertainties only for correlation volumes that are different with respect to those describing proton yields and a similar measurement of net-proton number fluctuations.

Enhanced Deuteron Coalescence Probability in Jets

The transverse-momentum (p_{T}) spectra and coalescence parameters B_{2} of (anti)deuterons are measured in p-p collisions at sqrt[s]=13  TeV for the first time in and out of jets. In this measurement, the direction of the leading particle with the highest p_{T} in the event (p_{T}^{lead}>5  GeV/c) is used as an approximation for the jet axis. The event is consequently divided into three azimuthal regions, and the jet signal is obtained as the difference between the toward region, that contains jet fragmentation products in addition to the underlying event (UE), and the transverse region, which is dominated by the UE. The coalescence parameter in the jet is found to be approximately a factor of 10 larger than that in the underlying event. This experimental observation is consistent with the coalescence picture and can be attributed to the smaller average phase-space distance between nucleons in the jet cone as compared with the underlying event. The results presented in this Letter are compared to predictions from a simple nucleon coalescence model, where the phase-space distributions of nucleons are generated using pythia8 with the Monash 2013 tuning, and to predictions from a deuteron production model based on ordinary nuclear reactions with parametrized energy-dependent cross sections tuned on data. The latter model is implemented in pythia8.3. Both models reproduce the observed large difference between in-jet and out-of-jet coalescence parameters, although the almost flat trend of the B_{2}^{Jet} is not reproduced by the models, which instead give a decreasing trend.

Impact of hole transport material on perovskite solar cells with different metal electrode: A SCAPS-1D simulation insight

The high efficiency and low cost of production of perovskite solar cells (PSCs) based on organic-inorganic halides have attracted the attention of researchers. However, due to the intricacy in the synthesis of Spiro-OMeTAD and the high cost of gold (Au) utilized as the back contact (BC), have affected its viability for commercialization. In this present study, a simulation was performed with and without HTM utilizing different metal contacts (Ag, Cr, Cu, Au, Ni and Pt). SCAPS-1D, a software program in one dimension, was used to conduct the simulation. A systematic analysis was done to determine how the metal back contact's work functions affected the PSC both with and without HTM. The outcomes demonstrate that the PSCs' photovoltaic performance is significantly influenced by the metal contact's work function (W_F). The best metal contact for HTM and HTM-free devices was Pt, with a metal work function of 5.65 eV. The initial power conversion efficiencies (PCEs) for the two configurations were 26.229% for HTM-free and 25.608% for HTM-based device. A number of parameters, including absorber thickness, interface defect density, and electron transport material (ETM) thickness, were varied to obtain optimal values of 0.8 μm for both HTM and HTM-free PSCs, 10⁰⁵ cm^-2 for both HTM and HTM-free PSCs, and 0.01 μm for both HTM and HTM-free PSCs. These values were then used to simulate the final HTM and HTM-free devices with a PCE of 27.423%, current density (J_sc) of 27.546 mA/cm², open circuit voltage (V_oc) of 1.239 V, and fill factor (FF) of 80.347% for HTM-free whereas PCE of 26.767% with J_sc of 27.545 mA/cm², V_oc of 1.250 V, and FF of 77.733% for HTM based. These outcomes reflect outstanding enhancement of ∼1.05 and ∼1.07 times in PCE and J_sc over unoptimized cells with and without HTM.

Insight into the structural, optoelectronic, and thermoelectric properties of Fe2HfSi Heusler by DFT investigation

At high pressure, the pressure dependencies of the structural, electronic, optical, and thermoelectric properties of Fe₂HfSi Heusler were calculated using the FP-LAPW method within the framework of the density functional theory. The calculations were carried out using the modified Becke-Johnson (mBJ) scheme. Our calculations showed that the Born mechanical stability criteria confirmed the mechanical stability in the cubic phase. Further, through Poisson and Pugh's ratios critical limits, the findings of the ductile strength were computed. At a pressure of 0 GPa, the indirect nature of the material may be deduced from the electronic band structures of Fe₂HfSi as well as the estimations for its density of states. Under pressure, the real and imaginary dielectric function responses, optical conductivity, absorption coefficient, energy loss function, refractive index, reflectivity, and extinction coefficient were computed in the 0-12 eV range. Using semi-classical Boltzmann theory, a thermal response is also studied. As the pressure rises, the Seebeck coefficient decreases, while the electrical conductivity rises. The figure of merit (ZT) and Seebeck coefficients were determined at temperatures of 300 K, 600 K, 900 K, and 1200 K in order to better understand the thermoelectric properties of a material at these different temperatures. Despite the fact that the ideal Seebeck coefficient for Fe₂HfSi was discovered at 300 K and was determined to be superior to that reported previously. Materials with a thermoelectric reaction has been shown to be suitable for reusing waste heat in systems. As a result, Fe₂HfSi functional material may aid in the development of new energy harvesting and optoelectronic technologies.

Issue 2 - "Update on adverse respiratory effects of indoor air pollution". Part 2): Indoor air pollution and respiratory diseases: Perspectives from Italy and some other GARD countries

OBJECTIVE

to synthesize the Italian epidemiological contribution to knowledge on indoor pollution respiratory impact, and to analyze the perspective of some GARD countries on the health effects of indoor air pollution.

RESULTS

Italian epidemiological analytical studies confirmed a strong relationship between indoor air pollution and health in general population. Environmental tobacco smoke, biomass (wood/coal) fuel for cooking/heating and indoor allergens (house dust mites, cat and dog dander, mold/damp) are the most relevant indoor pollution sources and are related to respiratory and allergic symptoms/diseases in Italy and in other GARD countries such as Mexico, Brazil, Vietnam, India, Nepal and Kyrgyzstan. Community-based global health collaborations are working to improve prevention, diagnosis and care of respiratory diseases around the world, specially in low- and middle-income countries, through research and education.

CONCLUSIONS

in the last thirty years, the scientific evidence produced on respiratory health effects of indoor air pollution has been extensive, but the necessity to empower the synergies between scientific community and local administrations remains a challenge to address in order to implement effective interventions. Based on abundant evidence of indoor pollution health effect, WHO, scientific societies, patient organizations and other members of the health community should work together to pursue the GARD vision of "a world where all people breathe freely" and encourage policy makers to increase their engagement in advocacy for clean air.

Indian Guidelines on Nebulization Therapy

Inhalational therapy, today, happens to be the mainstay of treatment in obstructive airway diseases (OADs), such as asthma, chronic obstructive pulmonary disease (COPD), and is also in the present, used in a variety of other pulmonary and even non-pulmonary disorders. Hand-held inhalation devices may often be difficult to use, particularly for children, elderly, debilitated or distressed patients. Nebulization therapy emerges as a good option in these cases besides being useful in the home care, emergency room and critical care settings. With so many advancements taking place in nebulizer technology; availability of a plethora of drug formulations for its use, and the widening scope of this therapy; medical practitioners, respiratory therapists, and other health care personnel face the challenge of choosing appropriate inhalation devices and drug formulations, besides their rational application and use in different clinical situations. Adequate maintenance of nebulizer equipment including their disinfection and storage are the other relevant issues requiring guidance. Injudicious and improper use of nebulizers and their poor maintenance can sometimes lead to serious health hazards, nosocomial infections, transmission of infection, and other adverse outcomes. Thus, it is imperative to have a proper national guideline on nebulization practices to bridge the knowledge gaps amongst various health care personnel involved in this practice. It will also serve as an educational and scientific resource for healthcare professionals, as well as promote future research by identifying neglected and ignored areas in this field. Such comprehensive guidelines on this subject have not been available in the country and the only available proper international guidelines were released in 1997 which have not been updated for a noticeably long period of over two decades, though many changes and advancements have taken place in this technology in the recent past. Much of nebulization practices in the present may not be evidence-based and even some of these, the way they are currently used, may be ineffective or even harmful. Recognizing the knowledge deficit and paucity of guidelines on the usage of nebulizers in various settings such as inpatient, out-patient, emergency room, critical care, and domiciliary use in India in a wide variety of indications to standardize nebulization practices and to address many other related issues; National College of Chest Physicians (India), commissioned a National task force consisting of eminent experts in the field of Pulmonary Medicine from different backgrounds and different parts of the country to review the available evidence from the medical literature on the scientific principles and clinical practices of nebulization therapy and to formulate evidence-based guidelines on it. The guideline is based on all possible literature that could be explored with the best available evidence and incorporating expert opinions. To support the guideline with high-quality evidence, a systematic search of the electronic databases was performed to identify the relevant studies, position papers, consensus reports, and recommendations published. Rating of the level of the quality of evidence and the strength of recommendation was done using the GRADE system. Six topics were identified, each given to one group of experts comprising of advisors, chairpersons, convenor and members, and such six groups (A-F) were formed and the consensus recommendations of each group was included as a section in the guidelines (Sections I to VI). The topics included were: A. Introduction, basic principles and technical aspects of nebulization, types of equipment, their choice, use, and maintenance B. Nebulization therapy in obstructive airway diseases C. Nebulization therapy in the intensive care unit D. Use of various drugs (other than bronchodilators and inhaled corticosteroids) by nebulized route and miscellaneous uses of nebulization therapy E. Domiciliary/Home/Maintenance nebulization therapy; public & health care workers education, and F. Nebulization therapy in COVID-19 pandemic and in patients of other contagious viral respiratory infections (included later considering the crisis created due to COVID-19 pandemic). Various issues in different sections have been discussed in the form of questions, followed by point-wise evidence statements based on the existing knowledge, and recommendations have been formulated.

TB control in India in the COVID era

COVID-19 pandemic has disturbed the delivery of health care in almost all countries of the world. This has affected mostly the public health control programs. Because of lock downs, restrictions in movement, psychological fear of contacting the disease in health care facilities, diversion of health care workers for containment and management of COVID-19, utilization of diagnostic facilities like CBNAAT machines for COVID work, conversion of hospitals for care of these patients, financial diversion etc has created issues in the NTEP to focuss on TB control in India. Case notification and other areas of the program to achieve End TB by 2025 have suffered. Various ways of overcoming these difficulties have been discussed.

White paper on Ivermectin as a potential therapy for COVID-19

A group of senior doctors with vast clinical experience met on 19th July'20 under the aegis of Academy of Advanced Medical Education. The panel looked at Ivermectin, one of the old molecule and evaluated it's use in COVID 19 (Novel Coronavirus Disease 2019) management. After critical panel discussion, all the attending doctors came to a conclusion that Ivermectin can be a potential molecule for prophylaxis and treatment of people infected with Coronavirus, owing to its anti-viral properties coupled with effective cost, availability and good tolerability and safety.

Diagnoses and management of adult cough: An Indian Environmental Medical Association (EMA) position paper

BACKGROUND

Cough is a common yet distressing symptom that results in significant health care costs from outpatient visits and related consultations.

OBJECTIVE

The understanding of the pathobiology of cough in recent times has undergone an evolution with Cough hypersensitivity syndrome (CHS) being suggested in most cases of dry cough. However, in the case of productive cough, ancillary mechanisms including impaired Mucociliary clearance, in addition to hypermucosecretory bronchospastic conditions of Smoker's cough, asthma-COPD overlap, bronchiectasis, and allergic bronchopulmonary aspergillosis, need to be critically addressed while optimizing patient care with symptomatic therapy in outpatient settings of India.

METHODS

In this review, evidence-based graded recommendations on use of antitussives - & protussives as a Position Paper were developed based on the Level and Quality of Scientific evidence as per Agency for Health Care and Quality (AHRQ) criteria listing and Expert opinions offered by a multidisciplinary EMA panel in India.

RESULTS

Management of acute or chronic cough involves addressing common issues of environmental exposures and patient concerns before instituting supportive therapy with antitussives or bronchodilatory cough formulations containing mucoactives, anti-inflammatory, or short-acting beta-2 agonist agents.

CONCLUSION

The analyses provides a real world approach to the management of acute or chronic cough in various clinical conditions with pro- or antitussive agents while avoiding their misuse in empirical settings.

Comparative evaluation of loop-mediated isothermal amplification (LAMP) assay, GeneXpert MTB/Rif and multiplex PCR for the diagnosis of tubercular lymphadenitis in HIV-infected patients of North India

BACKGROUND

Tubercular lymphadenitis (TBLA) is one of the most common extrapulmonary manifestations of tuberculosis in patients with HIV. With several other pathological conditions presenting as lymphadenitis and lack of consensus regarding a gold standard test, the diagnosis of TBLA remains a challenge for the clinician.

OBJECTIVES

and design: In this study, we have assessed the potential of loop-mediated isothermal amplification (LAMP) test for the diagnosis of TBLA in HIV-infected patients. The study group included samples collected by fine needle aspiration (FNAC) of lymph nodes from 24 HIV-infected patients with TBLA. A composite reference standard was used to identify cases of TBLA based on clinical suspicion, results of cytology, AFB smear, MGIT culture, GeneXpert MTB/RIF, multiplex polymerase chain reaction (MPCR) and subsequently clinical response to antitubercular therapy. These tests were also carried out in 26 control samples of lymph node FNAC from HIV-infected patients with non-tubercular lymphadenitis.

RESULTS

LAMP assay was positive in 19/24 TBLA cases and yielded a sensitivity of 79.17% with 100% specificity. Cytology was suggestive in 18/24 (75%) TBLA cases. GeneXpert MTB/RIF assay correctly identified 16/24 TBLA cases, but the test did show one false positive result reducing its specificity. MPCR had the highest sensitivity of 91.67% as it correctly identified 22/24 cases and showed no false positive result.

CONCLUSION

The current study highlights the potential of LAMP test for the specific diagnosis of tubercular lymphadenitis in FNAC samples from HIV-infected patients, especially when cytology is either non-conclusive or non-available. Though MPCR had a higher sensitivity than LAMP assay, the added advantages of low cost, minimal technical expertise and simplicity of procedure make LAMP assay a suitable diagnostic test in resource-limited settings.

Guidelines for diagnostic flexible bronchoscopy in adults: Joint Indian Chest Society/National College of chest physicians (I)/Indian association for bronchology recommendations

Flexible bronchoscopy (FB) is commonly performed by respiratory physicians for diagnostic as well as therapeutic purposes. However, bronchoscopy practices vary widely across India and worldwide. The three major respiratory organizations of the country supported a national-level expert group that formulated a comprehensive guideline document for FB based on a detailed appraisal of available evidence. These guidelines are an attempt to provide the bronchoscopist with the most scientifically sound as well as practical approach of bronchoscopy. It involved framing appropriate questions, review and critical appraisal of the relevant literature and reaching a recommendation by the expert groups. The guidelines cover major areas in basic bronchoscopy including (but not limited to), indications for procedure, patient preparation, various sampling procedures, bronchoscopy in the ICU setting, equipment care, and training issues. The target audience is respiratory physicians working in India and well as other parts of the world. It is hoped that this document would serve as a complete reference guide for all pulmonary physicians performing or desiring to learn the technique of flexible bronchoscopy.

Non-overlapping small polaron tunneling conduction coupled dielectric relaxation in weak ferromagnetic NiAl2O4

The inverse spinel nickel aluminate micro-particles was successfully synthesized via solid-state synthesis techniques. The single phase cubic structure with space group Fd3m of the as-prepared sample was entrenched from Rietveld refinement of x-ray diffraction pattern. In addition, the photoluminescence (PL) and FTIR spectra were also performed to give strong evidence of its pure phase formation. The narrow hysteresis m-h loop and UV-DRS spectra at room temperature demonstrate its weak ferromagnetic and semiconducting nature with saturation magnetization 64.96  ×  10^-3 emu gm^-1 and direct optical band gap 2.03 eV respectively. The high-resolution FESEM micrographs and EDS elemental analysis exhibit its grain growth in µm range (217 µm) and presence of elemental compound Ni, Al and O respectively. The electrical transport properties were accomplished by complex impedance spectroscopy as a function of frequency (100 Hz-1 MHz) with the evolution of high temperature (300 °C-500 °C). The Nyquist plots (Z″ versus Z') were well fitted with an equivalent circuit model (QR) (QR) consisting of a series combination of intra and inter-granular contribution. Furthermore, the imaginary modulus spectra were also fitted with Kohlrausch-Williams-Watts (KWW) function, which represents two thermally activated peaks of grain and grain boundary effects. The low-frequency dispersive ac conductivity was elucidated using the following equation: [Formula: see text]. The increasing nature of temperature dependent frequency exponent (n) suggests the quantum mechanical tunneling: non-overlapping small polaron tunneling (NSPT) concept for conduction mechanism. In low-frequency region, the lattice and charge carrier polarization simultaneously contribute in dielectric permittivity.

A loop-mediated isothermal amplification assay for the diagnosis of pulmonary tuberculosis

Quantitated Mycobacterium tuberculosis (M.tb) H37Rv DNA was used to analyse the sensitivity and the specificity was assessed using DNA isolated from the reference strain H37Rv, 12 nontuberculous mycobacterium (NTM) species and five nonmycobacterium species. Furthermore, performance of the assay was evaluated on the sputum samples and compared with smear microscopy, culture and PCR. mpt64 (also called mpb64 or Rv1980c) loop-mediated isothermal amplification (LAMP) successfully detected 1 pg DNA within 40 min and successfully rejected NTMs and other bacterial species tested. It specifically detected all the 119 confirmed TB cases and 100 of the 104 control cases. The resulting sensitivity and specificity of LAMP assay was found to be 100% (95% CI: 96·79-100%) and 96·15% (95% CI; 90·44-98·94%) respectively. SIGNIFICANCE AND IMPACT OF THE STUDY: Loop-mediated isothermal amplification (LAMP) is a technique for isothermal DNA amplification suitable for cost-limited settings as it prevents the use of sophisticated instruments. Using mpt64 antigenic protein gene, we developed a LAMP assay especially for organisms of the M. tuberculosis complex. mpt64 LAMP assay showed 100% sensitivity and detected all the bacteriologically and clinically positive TB cases not detected by smear, culture or PCR methods.

Joint Indian Chest Society-National College of Chest Physicians (India) guidelines for spirometry

Although a simple and useful pulmonary function test, spirometry remains underutilized in India. The Indian Chest Society and National College of Chest Physicians (India) jointly supported an expert group to provide recommendations for spirometry in India. Based on a scientific grading of available published evidence, as well as other international recommendations, we propose a consensus statement for planning, performing and interpreting spirometry in a systematic manner across all levels of healthcare in India. We stress the use of standard equipment, and the need for quality control, to optimize testing. Important technical requirements for patient selection, and proper conduct of the vital capacity maneuver, are outlined. A brief algorithm to interpret and report spirometric data using minimal and most important variables is presented. The use of statistically valid lower limits of normality during interpretation is emphasized, and a listing of Indian reference equations is provided for this purpose. Other important issues such as peak expiratory flow, bronchodilator reversibility testing, and technician training are also discussed. We hope that this document will improve use of spirometry in a standardized fashion across diverse settings in India.

Evolving epidemiology of lung cancer in India: Reducing non-small cell lung cancer-not otherwise specified and quantifying tobacco smoke exposure are the key

BACKGROUND

Adenocarcinoma is the most prevalent histological type of lung cancer (LC) in developed countries while squamous cell carcinoma (SqCC) has so far been the most common type at our center. Herein, we report our continued assessment of the epidemiological trend of LC aimed at determining any change in the histological distribution.

METHODS

Retrospective analysis involving all consecutive newly diagnosed LC patients over a 4-year period (March 2011-February 2015). Demographic characteristics, histology, and staging data for current data set were compared with our previously published data (2008-2011). As before, smoking index (SI) was used to group patients as never (SI = 0), light (SI = 1-100), moderate (SI = 101-300), and heavy (SI ≥301) smokers.

RESULTS

Majority of 1301 patients had advanced disease (Stages IIIB = 30.1%; IV = 53.3%), were males (82.3%) and current/ex-smokers (76.9%). Adenocarcinoma and SqCC (36.4% each) were equally prevalent. As compared to our previous study, adenocarcinoma increased (36.4% vs. 27.5%) and nonsmall cell lung cancer-not otherwise specified (NSCLC-NOS) decreased (5.1% vs. 10.9%) significantly (P < 0.001). The current study had more heavy smokers (68.3% vs. 61.1%; P = 0.013) and median SI was also higher (500 vs. 400; P = 0.001). Among SI-based groups, significant differences were observed for age, gender, body mass index, histology, TNM stage, and metastatic disease distribution.

CONCLUSION

Reduction in NSCLC-NOS has led to adenocarcinoma and SqCC being equally prevalent at our center in North India despite an increase in heavy smokers. Accurate histological NSCLC subtyping is necessary for optimal epidemiological assessment.

Evaluation of the TB-LAMP assay for the rapid diagnosis of pulmonary tuberculosis in Northern India

SETTING

A tertiary care hospital in North India.

OBJECTIVE

To evaluate a commercial kit-based loop-mediated isothermal amplification (TB-LAMP) assay for the diagnosis of pulmonary tuberculosis (PTB).

DESIGN

A total of 530 patients presenting with PTB symptoms were enrolled and one sputum sample was collected from each patient. The TB-LAMP assay (Loopamp™ MTBC Detection kit) was performed on the raw sputum sample. The remaining sample was used for smear microscopy and mycobacterial culture. A cartridge-based nucleic acid amplification test (NAAT, Xpert® MTB/RIF assay) was also performed on the processed pellet.

RESULTS

The sensitivity and specificity of the TB-LAMP assay in culture-positive samples obtained from 453 patients presenting with PTB symptoms (77 specimens were excluded) were respectively 100% (95%CI 94.7-100) and 99.2% (95%CI 97.8-99.8). The sensitivity and specificity of Xpert in culture-positive samples were respectively 82.6% (95%CI 71.5-90.6) and 94.9% (95%CI 92.2-96.8). A concordance of 0.75 was obtained between the two NAATs (TB-LAMP assay and Xpert) using the κ statistic.

CONCLUSION

The TB-LAMP assay showed high sensitivity and specificity with limited requirement of testing infrastructure, and is thus a promising diagnostic tool for TB diagnosis in resource-poor settings.

Meta-analysis of Indian studies evaluating adenosine deaminase for diagnosing tuberculous pleural effusion

OBJECTIVE

To determine the diagnostic accuracy of pleural fluid adenosine deaminase (ADA) in diagnosing tuberculous pleural effusion (TPE) among Indian patients using systematic review and meta-analysis.

DESIGN

The PubMed, Embase, IndMED and Cochrane databases and other relevant publications were searched to identify Indian studies evaluating the sensitivity and specificity of ADA in diagnosing TPE. Pooled diagnostic accuracy measures and 95% confidence intervals (95%CI) were generated using a bivariate random-effects model, and examined using forest plots and hierarchical summary receiver operating characteristic (HSROC) curves.

RESULTS

Forty publications with 3524 patients were studied. Pooled sensitivity, specificity and diagnostic odds ratio estimates were high (0.94, 95%CI 0.89-0.96; 0.89, 95%CI 0.83-0.93; and 119.85, 95%CI 48.35-297.08, respectively). The area under the HSROC curve was 0.966. The most common ADA threshold was 40 international units (IU)/l in 18 studies. Pooled positive and negative likelihood ratios for thresholds between 38 and 42 IU/l were respectively 6.80 (95%CI 4.18-11.07) and 0.06 (95%CI 0.03-0.11). There was no clear change in diagnostic performance with increasing ADA thresholds. Multivariate meta-regression did not reveal any factor that significantly influenced the substantial heterogeneity between studies.

CONCLUSION

Pleural fluid ADA has good diagnostic accuracy for TPE in Indian patients, and appears more useful at excluding TPE at a threshold value of around 40 IU/l.

Temperature Controlled Evolution of Silver Polypods from Biomass Encapsulated Nano-Droplets

Silver nanoparticles are produced by a novel biosynthesis technique using fungus Penicillium purpurogenum NPMF (MTCC 7356). The biomass when subjected to heat treatment up to 700 °C produces the nanoparticles of silver due to the presence of free carbon which acts as encapsulation for silver nanoparticles. Increase in temperature above 700 °C causes a reduction in concentration of free carbon so that the nanoparticles come close to each other and form clusters in the shape of tetrapods to polypods. The micro-Raman analysis supports the formation of mesoporous carbon with increase in the calcined temperature. The formation of Ag nanostructures has been explained in terms of free energy diagram i.e., the crystal favors more to grow on (100) facet or (110) facet rather than on (111) facet by the addition of silver atoms and thereby, it releases more energy. The release of energy has been confirmed from the differential thermo gravimetric analysis. In fact, it is the dynamics of the minimization of the free energy of the system which governs the reorientation and rearrangement of Ag themselves leading to formation of various types of polypods. A formation mechanism is presented schematically.

GenoType MTBDRplus assay for screening and characterization of isoniazid and rifampicin resistance-associated mutations in multidrug-resistant Mycobacterium tuberculosis from India

Multidrug resistant tuberculosis (MDR-TB) is rising and the World Health Organization has recommended the line probe assay (LPA) for screening. In this study we assess LPA at a tertiary care centre from North India in 1758 samples from suspected MDR-TB cases. All smear-positive and/or Mycobacterium tuberculosis culture confirmed cases (n = 1170) were subjected to the GenoType-MTBDR assay. Amongst these the majority were retreatment cases, smear-positive at diagnosis (n = 637). An MDR prevalence of 7·8% was observed with the highest cases reported amongst MDR contacts (33·3%). The most common rifampicin resistance encoding mutation seen overall and in individual patient groups was H531L (53·3%). A higher prevalence of H526D mutation was observed in retreatment cases, smear-positive at 4 months of anti-tubercular therapy vs other patient groups (P = 0·052). The most common mutation encoding isoniazid resistance was S315T1 in the katG (79·9%) and C-15T in the inhA gene (91·1%). Thirty rifampicin and nine isoniazid resistant isolates had wild type gene deletion but no detectable mutation by LPA. Although LPA is a practical and rapid screening method for most mutations expected to result in MDR-TB, we observed that it only detects the known major mutations in specific genes. Such studies can provide the knowledge required to formulate customized strips based on prevalent mutations in our region and in specific patient groups.

SIGNIFICANCE AND IMPACT OF THE STUDY

To the best of our knowledge this is the largest study evaluating the GenoType-MTBDR line probe assay from India. We have studied the prevalence of mutations encoding rifampicin and isoniazid resistance in different patient groups based on criteria for multidrug resistance (MDR) suspicion. The translational impact of this study is in the design of customized country- or region-wise line probe assay strips. The identification of a few mutations in particular patient groups and the detection of wild type deletion mutants with no observable mutations both point toward the need for such customization enabling us to combat the rising trend of MDR tuberculosis.