Observation of a Long-lived Electronic Coherence Modulated by Vibrational Dynamics in Molecular Nd3+ -Complexes at Room Temperature.

Temporally delayed, phase-locked coherent pairs of near IR femtosecond laser pulses were employed to study electronic coherences in molecular Nd3+ -complexes at room temperature. Dissolved and solid complexes were studied under a confocal microscope set-up with fluorescence detection. The observed electronic coherence on a few hundred femtoseconds time scale is modulated by additional coherent wave packet dynamics, which we attribute mainly to be vibrational in nature. In future, the complexes may serve as prototypes for possible applications in quantum information technology.

Pulse length dependence of photoelectron circular dichroism.

We investigate photoelectron circular dichroism (PECD) with coherent light sources whose pulse durations range from femtoseconds to nanoseconds. To that end, we employed an optical parametric amplifier, an ultraviolet optical pulse shaper, and a nanosecond dye laser, all centered around a wavelength of 380 nm. A multiphoton ionization experiment on the gas-phase chiral prototype fenchone found that PECD measured via the 3s intermediate resonance is about 15% and robust over five orders of magnitude of the pulse duration. PECD remains robust despite ongoing molecular dynamics such as rotation, vibration, and internal conversion. We used the Lindblad equation to model the molecular dynamics. Under the assumption of a cascading internal conversion, from the 3p to the 3s and further to the ground state, we estimated the lifetimes of the internal conversion processes in the 100 fs regime.

Mathematical modelling of COVID-19: A case study of Italy.

This manuscript describes a mathematical epidemiological model of COVID-19 to investigate the dynamics of this pandemic disease and we have fitted this model to the current COVID-19 cases in Italy. We have obtained the basic reproduction number which plays a crucial role on the stability of disease free equilibrium point. Backward bifurcation with respect to the cure rate of treatment occurs conditionally. It is clear from the sensitivity analysis that the developments of self immunities with proper maintaining of social distancing of the exposed and asymptomatic individuals play key role for controlling the disease. We have validated the model by considering the COVID-19 cases of Italy and the future situations of epidemicity in Italy have been predicted from the model. We have estimated the basic reproduction number for the COVID-19 outbreak in Italy and effective reproduction number has also been studied. Finally, an optimal control model has been formulated and solved to realize the positive impacts of adapting lock down by many countries for maintaining social distancing.

COVID-19 pandemic in India: a mathematical model study.

The present novel coronavirus (SARS-CoV-2) infection has created a global emergency situation by spreading all over the world in a large scale within very short time period. But there is no vaccine, anti-viral medicine for such infection. So at this moment, a major worldwide problem is that how we can control this pandemic. On the other hand, India is high population density country, where the coronavirus infection disease (COVID-19) has started from 1 March 2020. Due to high population density, human to human social contact rate is very high in India. So controlling pandemic COVID-19 in early stage is very urgent and challenging problem of India. Mathematical models are employed to study the disease dynamics, identify the influential parameters and access the proper prevention strategies for reduction outbreak size. In this work, we have formulated a deterministic compartmental model to study the spreading of COVID-19 and estimated the model parameters by fitting the model with reported data of ongoing pandemic in India. Sensitivity analysis has been done to identify the influential model parameters. The basic reproduction number has been estimated from actual data and the effective basic reproduction number has been studied on the basis of reported cases. Some effective preventive measures and their impact have also been studied. Prediction are given on the future trends of the virus transmission under some control measures. Finally, the positive measures to control the disease have been summarized in the conclusion section.

On the electronically nonadiabatic decomposition dynamics of furazan and triazole energetic molecules.

The combined results of ab initio electronic-structure calculations, nonadiabatic molecular dynamics simulations using ab initio multiple spawning, and previous spectroscopic investigations of jet-cooled molecules provide strong evidence of a (π,σ*)-mediated decomposition mechanism for the furazan and triazole energetic molecules. The importance of dissociative excited states formed by electron promotion from a π molecular orbital to a σ* molecular orbital is explored for the furazan and triazole energetic molecules. Dissociative (π,σ*) states of furazan and triazole energetic molecules can be populated by nonadiabatic surface jump from the (π,π*) or the (n,π*) state. Finally, conical intersections between (π,σ*) potential energy surfaces (PESs) and the ground PES influence the eventual fragmentation dynamics of the furazan and triazole energetic molecules. Due to structural similarity of the triazole molecule with the pyrrole molecule, a comparison of nonadiabatic dynamics of these two molecules is also presented. The N-N bond dissociation is found to be a barrierless pathway for the triazole molecule, whereas the N-H bond dissociation exhibits a barrierless pathway for the pyrrole molecule. The present work, thus, provides insights into the excited-state chemistry of furazan and triazole energetic functional groups. The same insight can also be relevant for other energetic molecules.

Sub-500 fs electronically nonadiabatic chemical dynamics of energetic molecules from the S1 excited state: Ab initio multiple spawning study.

Energetic materials store a large amount of chemical energy. Different ignition processes, including laser ignition and shock or compression wave, initiate the energy release process by first promoting energetic molecules to the electronically excited states. This is why a full understanding of initial steps of the chemical dynamics of energetic molecules from the excited electronic states is highly desirable. In general, conical intersection (CI), which is the crossing point of multidimensional electronic potential energy surfaces, is well established as a controlling factor in the initial steps of chemical dynamics of energetic molecules following their electronic excitations. In this article, we have presented different aspects of the ultrafast unimolecular relaxation dynamics of energetic molecules through CIs. For this task, we have employed ab initio multiple spawning (AIMS) simulation using the complete active space self-consistent field (CASSCF) electronic wavefunction and frozen Gaussian-based nuclear wavefunction. The AIMS simulation results collectively reveal that the ultrafast relaxation step of the best energetic molecules (which are known to exhibit very good detonation properties) is completed in less than 500 fs. Many, however, exhibit sub-50 fs dynamics. For example, nitro-containing molecules (including C-NO2, N-NO2, and O-NO2 active moieties) relax back to the ground state in approximately 40 fs through similar (S1/S0)CI conical intersections. The N3-based energetic molecule undergoes the N2 elimination process in 40 fs through the (S1/S0)CI conical intersection. Nitramine-Fe complexes exhibit sub-50 fs Fe-O and N-O bond dissociation through the respective (S1/S0)CI conical intersection. On the other hand, tetrazine-N-oxides, which are known to exhibit better detonation properties than tetrazines, undergo internal conversion in a 400-fs time scale, while the relaxation time of tetrazine is very long (about 100 ns). Many other characteristics of sub-500 fs nonadiabatic decay of energetic molecules are discussed. In the end, many unresolved issues associated with the ultrafast nonadiabatic chemical dynamics of energetic molecules are presented.

Ab initio multiple spawning dynamics study of dimethylnitramine and dimethylnitramine-Fe complex to model their ultrafast nonadiabatic chemistry.

Conical intersections are now firmly established to be the key features in the excited electronic state processes of polyatomic energetic molecules. In the present work, we have explored conical intersection-mediated nonadiabatic chemical dynamics of a simple analogue nitramine molecule, dimethylnitramine (DMNA, containing one N-NO2 energetic group), and its complex with an iron atom (DMNA-Fe). For this task, we have used the ab initio multiple spawning (AIMS) dynamics simulation at the state averaged-complete active space self-consistent field(8,5)/6-31G(d) level of theory. We have found that DMNA relaxes back to the ground (S0) state following electronic excitation to the S1 excited state [which is an (n,π*) excited state] with a time constant of approximately 40 fs. This AIMS result is in very good agreement with the previous surface hopping-result and femtosecond laser spectroscopy result. DMNA does not dissociate during this fast internal conversion from the S1 to the S0 state. DMNA-Fe also undergoes extremely fast relaxation from the upper S1 state to the S0 state; however, this relaxation pathway is dissociative in nature. DMNA-Fe undergoes initial Fe-O, N-O, and N-N bond dissociations during relaxation from the upper S1 state to the ground S0 state through the respective conical intersection. The AIMS simulation reveals the branching ratio of these three channels as N-N:Fe-O:N-O = 6:3:1 (based on 100 independent simulations). Furthermore, the AIMS simulation reveals that the Fe-O bond dissociation channel exhibits the fastest (time constant 24 fs) relaxation, while the N-N bond dissociation pathway features the slowest (time constant 128 fs) relaxation. An intermediate time constant (30 fs) is found for the N-O bond dissociation channel. This is the first nonadiabatic chemical dynamics study of metal-contained energetic molecules through conical intersections.

Clinical Profile and Response to Treatment with Pegylated Interferon α 2b and Ribavirin in Chronic Hepatitis C-A Reappraisal from a Tertiary Care Center in Northern India.

AIM: To assess the clinical profile of 80 chronic hepatitis C patients in a tertiary health care center in Northern India and also to study the efficacy and tolerability of pegylated interferon (Peg-IFN) α 2b and ribavirin therapy in a cohort of chronic hepatitis C patients. METHODS: Thirty subjects with chronic hepatitis C (CH-C) with genotypes 2 and 3 received Peg-IFN α 2b 1.5 µg/kg subcutaneously weekly plus daily ribavirin 800 mg for 24 weeks .Subjects with genotype 1 infection received therapy for 48 weeks with ribavirin 1000 mg/day and Peg-IFN α 2b dose remained the same. The primary end point was the sustained viral response (SVR). Drug dosage was modified or temporarily discontinued if anemia or bone marrow suppression developed. RESULTS: The clinical profile of chronic hepatitis C infected patients showed decompensated cirrhosis in the more elderly patients. Genotype 3 was the commonest genotype and was seen in 21 (70%) patients. The mean baseline HCV RNA was high. SVR was achieved less commonly with genotype 1 than with genotype 2/3. Patients who became negative for HCV RNA at 4-weeks (rapid virological response or RVR) and 12 weeks (early virological response or EVR) of treatment showed significantly higher sustained virological response (SVR) rates. Similarly, patients who showed normalization of ALT level at 4-weeks and 12-weeks of treatment showed significant high rate of SVR. Overall treatment was well tolerated. CONCLUSION: In our region, CHC subjects have high viral load and genotype 3 being the most common. Treatment with Peg-IFN α 2b and ribavirin is effective and well tolerated. Genotype 1 was more resistant to the treatment. Patients who achieved RVR and EVR are more likely to achieve SVR. Although the numbers of patients in this study was small, considering the paucity of data of treatment from India, the data is relevant.

Intractable ascites as a manifestation of Wolman's disease: report of two sibs.

Wolman disease (WD) is a rare, inherited, rapidly fatal condition presenting in early infancy. The disease manifests in the first month of life with failure to thrive, vomiting, diarrhea, abdominal distension, hepatosplenomegaly and bilateral adrenal calcification and is nearly always fatal before the age of 1 year. Barring a case report of isolated fetal ascites, there is no report of intractable ascites as the presentation of WD till date. We report two siblings with WD who both had intractable ascites and required therapeutic paracentesis, albumin infusion, and diuretics to control tense ascites. Although rare, WD should be considered in the differential diagnosis of infantile ascites.

Profile of child labor in Indian railways.

OBJECTIVES: To determine the socio-medical profile of child workers in Indian railways. METHODS: This was a prospective longitudinal survey over one year. The children up to the age of 14 y entering the reserved second class sleeper compartment of long distance trains in Indian railways were included. The data were collected regarding their profile by the investigators either by interviewing or observation as per situation in the moving train in a predesigned proforma. Data pertaining to the social, demographic and medical aspects were collected. RESULTS: A total of eighty one children were noted in 22500 kilometers of train journey. Sex distribution (8:1) was unequal with males outnumbering females. CONCLUSIONS: This study, first of its kind, attempted to delineate a distinctive socio-medical profile in a special group of children. It might, on the behalf of social pediatrics, increase the awareness and help the society to formulate a rehabilitation policy in collaboration with national and international organizations.

Mohr-Claussen syndrome or oro-facial-digital syndrome (OFDS) type-II.

The Mohr-Claussen syndrome or oro-facial-digital syndrome type II (OFD-II)] is characterised by tongue lobulation, midline cleft lip, high arched or cleft palate, broad nasal root with wide bifid nasal tip, hypertelorism, micrognathia, brachydactyly, syndactyly and polydactyly, bilateral reduplicated hallux, conductive hearing loss and normal intelligence. In view of the different modes of inheritance and the different prognoses of the two oro-facio-digital syndromes, type 1 and type 2, it is important to establish a correct diagnosis in these patients. A neonate with features of oro-facio-digital syndrome, type-II is being reported and the distinguishing clinicoradiological features with type-I are compared.

Prophylactic probiotics for prevention of necrotizing enterocolitis in very low birth weight newborns.

Our study showed that enteral administration of prophylactic probiotics in neonatal intensive care setup could significantly reduce morbidity due to necrotising enterocolitis in very low birth weight newborn. It also helps in establishing early full enteral feeding and reduces hospital stay.

Extending the modified bayesian information criterion (mBIC) to dense markers and multiple interval mapping.

SUMMARY: The modified version of Bayesian Information Criterion (mBIC) is a relatively simple model selection procedure that can be used when locating multiple interacting quantitative trait loci (QTL). Our earlier work demonstrated the statistical properties of mBIC for situations where the average genetic map interval is at least 5 cM. In this work mBIC is adapted to genome searches based on a dense map and, more importantly, to the situation where consecutive QTL and interactions are located by multiple interval mapping. Easy to use formulas for the extended mBIC are given. A simulation study, as well as the analysis of real data, confirm the good properties of the extended mBIC.

Partitioning of quencher ions in the micellar microenvironment of polyoxyethylene nonyl phenol.

This paper has explored the quenching of fluorescence of the dye safranine T (ST) by the inorganic cations viz Cu2+, Co2+, Ni2+ and Mn2+ in micellar solutions of the surfactant dioxyethylene nonyl phenol (Igepal CO-210), pentaoxyethylene nonyl phenol (Igepal CO-520) and dodecaoxyethylene nonyl phenol (Igepal CO-720). The quenching results have been calculated in light of stern volmer equation (SV) to evaluate the extent of interaction between the fluorophore (ST) and quencher. The average concentration of the quencher ions in the micelle have been determined. The quenching efficiency of ST by inorganic ions in micellar medium is lower than that in aqueous medium. The results show that the ions get partitioned in the micellar medium. The values of the partition coefficient of the ions decrease with increase in HLB value and number of oxyethylene groups in Igepal.

Modifying the Schwarz Bayesian information criterion to locate multiple interacting quantitative trait loci.

The problem of locating multiple interacting quantitative trait loci (QTL) can be addressed as a multiple regression problem, with marker genotypes being the regressor variables. An important and difficult part in fitting such a regression model is the estimation of the QTL number and respective interactions. Among the many model selection criteria that can be used to estimate the number of regressor variables, none are used to estimate the number of interactions. Our simulations demonstrate that epistatic terms appearing in a model without the related main effects cause the standard model selection criteria to have a strong tendency to overestimate the number of interactions, and so the QTL number. With this as our motivation we investigate the behavior of the Schwarz Bayesian information criterion (BIC) by explaining the phenomenon of the overestimation and proposing a novel modification of BIC that allows the detection of main effects and pairwise interactions in a backcross population. Results of an extensive simulation study demonstrate that our modified version of BIC performs very well in practice. Our methodology can be extended to general populations and higher-order interactions.