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Since the discovery of graphene in 2004, the unique properties of two-dimensional materials have sparked intense research interest regarding their use as alternative materials in various photonic applications. Transition metal dichalcogenide monolayers have been proposed as transport layers in photovoltaic cells, but the promising characteristics of group IV-VI dichalcogenides are yet to be thoroughly investigated. This manuscript reports on monolayer Ge2Se2 (a group IV-VI dichalcogenide), its optoelectronic behavior, and its potential application in photovoltaics. When employed as a hole transport layer, the material fosters an astonishing device performance. We use ab initio modeling for the material prediction, while classical drift-diffusion drives the device simulations. Hybrid functionals calculate electronic and optical properties to maintain high accuracy. The structural stability has been verified using phonon spectra. The E-k dispersion reveals the investigated material's key electronic properties. The calculations reveal a direct bandgap of 1.12 eV for monolayer Ge2Se2. We further extract critical optical parameters using the Kubo-Greenwood formalism and Kramers-Kronig relations. A significantly large absorption coefficient and a high dielectric constant inspired the design of a monolayer Ge2Se2-based solar cell, exhibiting a high open circuit voltage of V oc = 1.11 V, a fill factor of 87.66%, and more than 28% power conversion efficiency at room temperature. Our findings advocate monolayer Ge2Se2 for various optoelectronic devices, including next-generation solar cells. The hybrid quantum-to-macroscopic methodology presented here applies to broader classes of 2D and 3D materials and structures, showing a path to the computational design of future photovoltaic materials.

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BACKGROUND: Pre-diagnosis attrition needs to be addressed urgently if we are to make progress in improving MDR-TB case detection and achieve universal access to MDR-TB care. We report the pre-diagnosis attrition, along with factors associated, and turnaround times related to the diagnostic pathway among patient with presumptive MDR-TB in Bhopal district, central India (2014). METHODS: Study was conducted under the Revised National Tuberculosis Control Programme setting. It was a retrospective cohort study involving record review of all registered TB cases in Bhopal district that met the presumptive MDR-TB criteria (eligible for DST) in 2014. In quarter 1, Line Probe Assay (LPA) was used if sample was smear/culture positive. Quarter 2 onwards, LPA and Cartridge-based Nucleic Acid Amplification Test (CbNAAT) was used for smear positive and smear negative samples respectively. Pre-diagnosis attrition was defined as failure to undergo DST among patients with presumptive MDR-TB (as defined by the programme). RESULTS: Of 770 patients eligible for DST, 311 underwent DST and 20 patients were diagnosed as having MDR-TB. Pre-diagnosis attrition was 60% (459/770). Among those with pre-diagnosis attrition, 91% (417/459) were not identified as 'presumptive MDR-TB' by the programme. TAT [median (IQR)] to undergo DST after eligibility was 4 (0, 10) days. Attrition was more than 40% across all subgroups. Age more than 64 years; those from a medical college; those eligible in quarter 1; patients with presumptive criteria 'previously treated - recurrent TB', 'treatment after loss-to-follow-up' and 'previously treated-others'; and patients with extra-pulmonary TB were independent risk factors for not undergoing DST. CONCLUSION: High pre-diagnosis attrition was contributed by failure to identify and refer patients. Attrition reduced modestly with time and one factor that might have contributed to this was introduction of CbNAAT in quarter 2 of 2014. General health system strengthening which includes improvement in identification/referral and patient tracking with focus on those with higher risk for not undergoing DST is urgently required.

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PURPOSE: To determine the demographic pattern, level, mechanism of traumatic amputation in children and adolescent age group and to compare findings with other studies. METHODS: Patients aged less than 18 years with traumatic amputation attending Department of Physical Medicine and Rehabilitation, King George's Medical University, Lucknow, India between July 2013 and January 2016 were enrolled and their demographic characteristics were analyzed. RESULTS: Fifty-three patients were included aged less than 18 years when injured. Mean age of the population studied was 9.89 ± 4.13 with male to females ratio of 3:2. Majority (69.81%) of traumatic amputations involved lower limb. Most common level was unilateral transtibial (35.85%), followed by transfemoral (16.98%). In upper limb, most common type was transradial. RTA followed by train accidents was most common mechanism of traumatic amputation. 8 patients needed revision surgery. 52.8% patients of acquired amputations complained of phantom sensation and 37.74% phantom pain. CONCLUSIONS: This study aims to visualize the current scenario and the data generated could be possibly helpful in planning policies and programs at institutional as well as at higher levels for prevention, treatment and distribution of resource to the young amputee population, to ensure their better health care and also opportunities in life.

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An ab initio study of the energetics, structural, and electronic properties of thin silver nanowires of Ag(n) with n = 1 to 6 has been made in density functional theory in local density approximation. The present study reveals that all of the wires are stable except the wire with 3 silver atoms per unit cell. The linear chain is comparatively less stable. The binding energies of the most stable wires lie in the range 2.60-3.18 eV/atom with maximum values for the 5-Ag pentagonal and the two 6-Ag (hexagonal and pyramidal) nanowires. The nearest neighbor Ag-Ag separations in all of the most stable wires up to n=6 is quite the same and is equal to 2.634 +/- 0.03 A. For the most stable 6-Ag pyramidal wire, the bond length increases to 2.75 or 2.81 A. The cross-sectional dimension of these wires are around 5.0 A. All of the studied silver wires are metallic. A majority of the sd mixed states cross the Fermi level. The density of state is maximum for the 5-Ag pentagonal and 6-Ag pyramidal nanowires, and so is the number of channels (5 or 6) crossing the E(F) which would be available for high electrical conduction.

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An ab-initio comprehensive study of the stability and structural and vibrational properties of small carbon clusters, CN for N = 1-10, has been made. We use a self-consistent pseudopotential method within density functional theory in the generalized gradient approximation considering spin polarization. The estimated values of binding energies for the various clusters are overestimated in the non-spin-polarized calculations. On the other hand, for the spin-polarized case, the computed binding energies are in very good agreement with the available experimental data. Also, the calculated vibrational frequencies for CN, N = 2-5, are in reasonable agreement with the available experimental values.

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