Publications by authors named "Gupta Arvind"

178 Publications

Dye-sensitized solar cells based on Fe N-heterocyclic carbene photosensitizers with improved rod-like push-pull functionality.

Chem Sci 2021 Dec 11;12(48):16035-16053. Epub 2021 Nov 11.

Centre for Analysis and Synthesis, Department of Chemistry, Lund University Box 124 SE-22100 Lund Sweden

A new generation of octahedral iron(ii)-N-heterocyclic carbene (NHC) complexes, employing different tridentate C^N^C ligands, has been designed and synthesized as earth-abundant photosensitizers for dye sensitized solar cells (DSSCs) and related solar energy conversion applications. This work introduces a linearly aligned push-pull design principle that reaches from the ligand having nitrogen-based electron donors, over the Fe(ii) centre, to the ligand having an electron withdrawing carboxylic acid anchor group. A combination of spectroscopy, electrochemistry, and quantum chemical calculations demonstrate the improved molecular excited state properties in terms of a broader absorption spectrum compared to the reference complex, as well as directional charge-transfer displacement of the lowest excited state towards the semiconductor substrate in accordance with the push-pull design. Prototype DSSCs based on one of the new Fe NHC photosensitizers demonstrate a power conversion efficiency exceeding 1% already for a basic DSSC set-up using only the I/I redox mediator and standard operating conditions, outcompeting the corresponding DSSC based on the homoleptic reference complex. Transient photovoltage measurements confirmed that adding the co-sensitizer chenodeoxycholic acid helped in improving the efficiency by increasing the electron lifetime in TiO. Time-resolved spectroscopy revealed spectral signatures for successful ultrafast (<100 fs) interfacial electron injection from the heteroleptic dyes to TiO. However, an ultrafast recombination process results in undesirable fast charge recombination from TiO back to the oxidized dye, leaving only 5-10% of the initially excited dyes available to contribute to a current in the DSSC. On slower timescales, time-resolved spectroscopy also found that the recombination dynamics (longer than 40 μs) were significantly slower than the regeneration of the oxidized dye by the redox mediator (6-8 μs). Therefore it is the ultrafast recombination down to fs-timescales, between the oxidized dye and the injected electron, that remains as one of the main bottlenecks to be targeted for achieving further improved solar energy conversion efficiencies in future work.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1039/d1sc02963kDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8672732PMC
December 2021

Reference intervals for reticulocyte parameters (reticulocyte haemoglobin equivalent and immature reticulocyte fraction) in first-trimester pregnancy.

J Obstet Gynaecol 2021 Dec 16:1-3. Epub 2021 Dec 16.

Department of Pathology and Laboratory Medicine, All India Institute of Medical Sciences, Rishikesh, Rishikesh, India.

Reticulocyte parameters including reticulocyte haemoglobin equivalent (Ret-He) and immature reticulocyte fraction (IRF) are newly recognised hematological parameters that are being used for diagnosis and follow-up of anaemic patients. Reference intervals of these parameters have been established in different populations, however, the data relating to pregnancy are still lacking. One hundred and fifty-five first-trimester pregnant females were screened and the reference interval was calculated after selecting the patient with fixed criteria. R statistical software was used for statistical calculations. We tried to establish a reference interval of Ret-He content and IRF in first-trimester pregnancy in our study.IMPACT STATEMENT Ret-He and IRF have been established as the marker of iron deficiency and iron-deficiency anaemia in different age groups and as a marker of response to iron therapy. However, literature is scarce regarding the reference intervals of these parameters, especially in pregnancy. This study establishes the reference interval of newer reticulocyte parameters in first-trimester pregnancy which is not yet established in the literature. Establishing a reference interval is required for any laboratory parameters to be used in the clinical context. The results of this study may help in making a clinical decision regarding iron deficiency in early pregnancy which is one of the common clinical problems in pregnancy. This study also serves as a baseline study for further studies of reference intervals for newer reticulocyte parameters in pregnancy. A similar study with a larger study population and follow-up with iron therapy may establish these parameters as one of the important markers of iron deficiency in pregnancy and help institute iron therapy on case-to-case basis.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1080/01443615.2021.1983781DOI Listing
December 2021

Cellulose nanocrystals enabled sustainable polycaprolactone based shape memory polyurethane bionanocomposites.

J Colloid Interface Sci 2022 Apr 1;611:726-738. Epub 2021 Dec 1.

Department of Chemical Engineering, University of Waterloo, Waterloo, ON, Canada; Institute of Polymer Research, University of Waterloo, Waterloo, ON, Canada; Waterloo Institute for Nanotechnology, University of Waterloo, Waterloo, ON, Canada. Electronic address:

In recent years, shape memory polyurethanes have gained substantial attention and are targeted for a range of smart and functional materials. In this work, the development of nanocrystalline celluloses (CNCs) enabled polycaprolactone-based shape memory polyurethane biocomposite using an in situ one-pot reactions is reported. The incorporation of up to 10 wt% CNCs resulted in a remarkable enhancement in the tensile strength at yield (from 0.2 MPa to 7.2 MPa), tensile strength at break (167% improvement), and modulus of elasticity (from 3.5 to 139.3 MPa) while maintaining the elongation at break. This was attributed to the simultaneous action of CNCs as a nucleating agent for crystallization and highly compatibilized reinforcing agent of the network. Moreover, the in situ incorporation of CNCs enhanced the shape memory capability of polyurethanes, which enables its employment in functional material applications, such as the biomedical sector. The intimate interfacial adhesion between the CNCs and the polymer matrix, which promoted shape fixating and recovery, was confirmed by fractured surface morphology studies. Rheology characterizations provided strong evidence that the addition of CNCs increased the shape fixity attributed to the stiffness of CNCs below the glass transition temperature (T) compared to the neat PU in conjuncture with the higher T of CNCs. Overall, the developed polymer nanocomposites are appealing materials for biomedical applications.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jcis.2021.11.174DOI Listing
April 2022

Oxygenated Cyclohexene Derivatives from the Stem and Root Barks of .

J Nat Prod 2021 Dec 21;84(12):3080-3089. Epub 2021 Nov 21.

Department of Chemistry-BMC, Uppsala University, SE-751 23 Uppsala, Sweden.

Five new cyclohexene derivatives, dipandensin A and B ( and ) and pandensenols A-C (-), and 16 known secondary metabolites (-) were isolated from the methanol-soluble extracts of the stem and root barks of . The structures were characterized by NMR spectroscopic and mass spectrometric analyses, and that of 6-methoxyzeylenol () was further confirmed by single-crystal X-ray crystallography, which also established its absolute configuration. The isolated metabolites were evaluated for antibacterial activity against the Gram-positive bacteria and and the Gram-negative bacteria , , , , and , as well as for cytotoxicity against the MCF-7 human breast cancer cell line. A mixture of uvaretin () and isouvaretin () exhibited significant antibacterial activity against (EC 8.7 μM) and (IC 7.9 μM). (8'α,9'β-Dihydroxy)-3-farnesylindole () showed strong inhibitory activity (EC 9.8 μM) against , comparable to the clinical reference ampicillin (EC 17.9 μM). None of the compounds showed relevant cytotoxicity against the MCF-7 human breast cancer cell line.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/acs.jnatprod.1c00811DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8713284PMC
December 2021

Three-in-One C H -Selectivity-Guided Adsorptive Separation across an Isoreticular Family of Cationic Square-Lattice MOFs.

Angew Chem Int Ed Engl 2022 Jan 16;61(4):e202114132. Epub 2021 Dec 16.

Department of Chemistry, Indian Institute of Science Education and Research (IISER), Pune, Dr. Homi Bhabha Road, Pashan, Pune, 411008, India.

Energy-efficient selective physisorption driven C H separation from industrial C2-C1 impurities such as C H , CO and CH is of great importance in the purification of downstream commodity chemicals. We address this challenge employing a series of isoreticular cationic metal-organic frameworks, namely iMOF-nC (n=5, 6, 7). All three square lattice topology MOFs registered higher C H uptakes versus the competing C2-C1 gases (C H , CO and CH ). Dynamic column breakthrough experiments on the best-performing iMOF-6C revealed the first three-in-one C H adsorption selectivity guided separation of C H from 1:1 C H /CO , C H /C H and C H /CH mixtures. Density functional theory calculations critically examined the C H selective interactions in iMOF-6C. Thanks to the abundance of square lattice topology MOFs, this study introduces a crystal engineering blueprint for designing C H -selective layered metal-organic physisorbents, previously unreported in cationic frameworks.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/anie.202114132DOI Listing
January 2022

Prescribing Patterns and Response to Antihyperglycemic Agents Among Novel Clusters of Type 2 Diabetes in Asian Indians.

Diabetes Technol Ther 2022 Jan 5. Epub 2022 Jan 5.

Department of Diabetology, Madras Diabetes Research Foundation and Dr. Mohan's Diabetes Specialities Centre, Chennai, India.

To assess the prescribing patterns and response to different classes of antihyperglycemic agents in novel clusters of type 2 diabetes (T2D) described in India. We attempted to replicate the earlier described clusters of T2D, in 32,867 individuals with new-onset T2D (within 2 years of diagnosis) registered between October 2013 and December 2020 at 15 diabetes clinics located across India, by means of k-means clustering utilizing 6 clinically relevant variables. Individuals who had follow-up glycated hemoglobin (HbA1c) up to 2 years were included for the drug response analysis ( = 13,247). Among the 32,867 participants included in the study, 20,779 (63.2%) were males. The average age at diagnosis was 45 years and mean HbA1c at baseline was 8.9%. The same four clusters described in India earlier were replicated. Forty percent of the study participants belonged to the mild age-related diabetes cluster, followed by insulin-resistant obese diabetes (27%), severe insulin-deficient diabetes (21%), and combined insulin-resistant and insulin-deficient diabetes (12%) clusters. The most frequently used antihyperglycemic agents were sulfonylureas, metformin, and dipeptidyl peptidase-4 inhibitors apart from insulin. While there were significant differences in HbA1c reduction between drugs across clusters, these were largely driven by differences in the baseline (pretreatment) HbA1c. In this new cohort, we were able to reliably replicate the four subtypes of T2D earlier described in Asian Indians. Prescribing patterns show limited usage of newer antihyperglycemic agents across all clusters. Randomized clinical trials are required to establish differential drug responses between clusters.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1089/dia.2021.0277DOI Listing
January 2022

Antibody response after first and second-dose of ChAdOx1-nCOV (Covishield®) and BBV-152 (Covaxin®) among health care workers in India: The final results of cross-sectional coronavirus vaccine-induced antibody titre (COVAT) study.

Vaccine 2021 10 24;39(44):6492-6509. Epub 2021 Sep 24.

Associate Professor, Dept. of Community Medicine, Mahatma Gandhi Medical College & Hospital, Jaipur, Rajasthan, India.

Background: We assessed the humoral immune response of both ChAdOx1-nCOV (Covishield) and BBV-152 (Covaxin) vaccines in Indian health care workers (HCW).

Methods: A Pan-India, Cross-sectional, Coronavirus Vaccine-induced Antibody Titre (COVAT) study was conducted that measured SARS-CoV-2 anti-spike binding antibody quantitatively, 21 days or more after the first and second dose of two vaccines in both severe acute respiratory syndrome (SARS-CoV-2) naïve and recovered HCW. Primary aim was to analyze antibody response (seropositivity rate, Geometric Mean Titre [GMT] and 95% Confidence Interval [CI]) following each dose of both vaccines and its correlation to age, sex, blood group, body mass index (BMI) and comorbidities. Here we report the results of anti-spike antibody response after first and two completed doses.

Results: Among the 515 HCW (305 Male, 210 Female) who took two doses of both vaccines, 95.0% showed seropositivity to anti-spike antibody. However, both seropositivity rate and GMT (95% CI) of anti-spike antibody was significantly higher in Covishield vs. Covaxin recipients (98.1 vs. 80.0%; 129.3 vs. 48.3 AU/mL; both p < 0.001). This difference persisted in 457 SARS-CoV-2 naïve and propensity-matched (age, sex and BMI) analysis of 116 participants. Age > 60-years, males, people with any comorbidities, and history of hypertension (HTN) had a significantly less anti-spike antibody GMT compared to age ≤ 60 years, females, no comorbidities and no HTN respectively, after the completion of two doses of either vaccine. Gender, presence of comorbidities, and vaccine type were independent predictors of antibody seropositivity rate and anti-spike antibody titre levels in multiple logistic and log transformed linear regression analysis. Both vaccine recipients had similar solicited mild to moderate adverse events and none had severe or unsolicited side effects.

Conclusions: Both vaccines elicited good immune response after two doses, although seropositivity rates and GMT of anti-spike antibody titre was significantly higher in Covishield compared to Covaxin recipients.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.vaccine.2021.09.055DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8461292PMC
October 2021

Variations in glycated haemoglobin with age among individuals with normal glucose tolerance: Implications for diagnosis and treatment-Results from the ICMR-INDIAB population-based study (INDIAB-12).

Acta Diabetol 2021 Oct 1. Epub 2021 Oct 1.

Madras Diabetes Research Foundation and Dr. Mohan's Diabetes Specialities Centre, ICMR Centre for Advanced Research On Diabetes, No 4, Conran Smith Road, Gopalapuram, Chennai, India.

Aim: To report on glycated haemoglobin (HbA1c) values among individuals with normal glucose tolerance (NGT) at different age groups, using data acquired from a large national survey in India.

Materials And Methods: Data on glycaemic parameters at different age groups were obtained from the Indian Council of Medical Research-INdia DIABetes (ICMR-INDIAB) study, in adults aged ≥ 20 years representing all parts of India. Age-wise distribution of HbA1c was assessed among individuals with NGT (n = 14,222) confirmed by an oral glucose tolerance test using the World Health Organization (WHO) criteria. Results were validated in another large epidemiological study (n = 1077) conducted in Chennai, India.

Results: Among NGT individuals, HbA1c increased gradually with age from 5.16 ± 0.71% (33 mmol/mol) in the age group of 20-29 years to 5.49 ± 0.69% (37 mmol/mol) in those aged 70 + years. In the validation study, conducted in another study population, HbA1c was 5.35 ± 0.43% (35 mmol/mol) in age group of 20-29 years and 5.74 ± 0.50% (39 mmol/mol) in those aged 70 and above. In the INDIAB study, for every decadal increase in age, there is a 0.08% increase in HbA1c and this increase was more significant in females (females: 0.10% vs. males: 0.06%) and in urban (urban: 0.10% vs. rural: 0.08%) population.

Conclusions: HbA1c levels increase steadily with age. This suggests that age-specific cutoffs be used while utilizing HbA1c to diagnose diabetes and prediabetes, so as to minimize the risk of overdiagnosis and unnecessary initiation of treatment in elderly people who could have physiological increase in HbA1c levels.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00592-021-01798-4DOI Listing
October 2021

Predicting the risk of rupture for vertebral aneurysm based on geometric features of blood vessels.

R Soc Open Sci 2021 Aug 11;8(8):210392. Epub 2021 Aug 11.

Research Centre for Mathematics, Advanced Institute of Natural Sciences, Beijing Normal University, Zhuhai, People's Republic of China.

A significant proportion of the adult population worldwide suffers from cerebral aneurysms. If left untreated, aneurysms may rupture and lead to fatal massive internal bleeding. On the other hand, treatment of aneurysms also involve significant risks. It is desirable, therefore, to have an objective tool that can be used to predict the risk of rupture and assist in surgical decision for operating on the aneurysms. Currently, such decisions are made mostly based on medical expertise of the healthcare team. In this paper, we investigate the possibility of using machine learning algorithms to predict rupture risk of vertebral artery fusiform aneurysms based on geometric features of the blood vessels surrounding but excluding the aneurysm. For each of the aneurysm images (12 ruptured and 25 unruptured), the vessel is segmented into distal and proximal parts by cross-sectional area and 382 non-aneurysm-related geometric features extracted. The decision tree model using two of the features (standard deviation of eccentricity of proximal vessel, and diameter at the distal endpoint) achieved 83.8% classification accuracy. Additionally, with support vector machine and logistic regression, we also achieved 83.8% accuracy with another set of two features (ratio of mean curvature between distal and proximal parts, and diameter at the distal endpoint). Combining the aforementioned three features with integration of curvature of proximal vessel and also ratio of mean cross-sectional area between distal and proximal parts, these models achieve an impressive 94.6% accuracy. These results strongly suggest the usefulness of geometric features in predicting the risk of rupture.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1098/rsos.210392DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8355691PMC
August 2021

Assessment of Sea Sickness in Naval Personnel: Incidence and Management.

Indian J Occup Environ Med 2021 Apr-Jun;25(2):119-124. Epub 2021 Jul 9.

Fleet Medical Centre, Mumbai, Maharashtra, India.

Background: Strategic, operational and tactical superiority of Navy hinges on extremely efficient warships which in turn depend on professionally competent sailors ready to undertake tasks to deliver timely, structured and metered response. Ships and their potentialities are tools to achieve the required strategic advantage which is dependent on the proficiency of sailors. Sailors who are fit ashore may be debilitated on board because of sea sickness.

Aims: To study the incidence and severity of sea sickness among 500 naval personnel from various ships. Setting and design: An observational study conducted from May 2019 to March 2020 among 500 naval personnel from various ships of the fleet.

Materials And Methods: Motion Sickness Assessment Questionnaire (MSAQ) was used to collect data from personnel of different departments working in different part of ship aged between 20 to 50 years.

Results: The majority suffered mild symptoms (78.78%) and did not require any medication. Their symptoms were selflimiting and settled on rest within 24 hours. Moderately severe symptoms were observed among 19.31 % personnel and had to be administered medication and rest for 24 hours. Only 1.91% had severe symptoms and had to be excused from duties along with medication and rest.

Conclusion: Sea sickness is unpleasant and has an adverse effect on employability of the sailors. It is mild and self limiting in majority of the personnel not requiring active intervention. Some personnel may require desensitisation along with pharmacotherapy.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.4103/ijoem.IJOEM_94_20DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8341412PMC
July 2021

Exclusion process on two intersecting lanes with constrained resources: Symmetry breaking and shock dynamics.

Phys Rev E 2021 Jul;104(1-1):014138

Department of Mathematics, Indian Institute of Technology Ropar, Rupnagar 140001, Punjab, India.

We present a study of the exclusion process on a peculiar topology of network with two intersecting lanes, competing for the particles in a reservoir with finite capacity. To provide a theoretical ground for our findings, we exploit mean-field approximation along with domain-wall theory. The stationary properties of the system, including phase transitions, density profiles, and position of the domain wall are derived analytically. Under the similar dynamical rules, the particles of both lanes interact only at the intersected site. The symmetry of the system is maintained until the number of particles do not exceed the total number of sites. However, beyond this, the symmetry breaking phenomenon occurs, resulting in the appearance of asymmetric phases and continues to persist even for an infinite number of particles. The complexity of the phase diagram shows a nonmonotonic behavior with an increasing number of particles in the system. A bulk induced shock appears in a symmetric phase, whereas, a boundary induced shock is observed in the symmetric as well as the asymmetric phase. Monitoring the location of localized shock with increasing entry of particles, we explain the possible phase transitions. The theoretical results are supported by extensive Monte Carlo simulations and explained using simple physical arguments.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1103/PhysRevE.104.014138DOI Listing
July 2021

Numerical method for parameter inference of systems of nonlinear ordinary differential equations with partial observations.

R Soc Open Sci 2021 Jul 28;8(7):210171. Epub 2021 Jul 28.

Duke Kunshan University, 8 Duke Ave, Kunshan, Jiangsu, People's Republic of China.

Parameter inference of dynamical systems is a challenging task faced by many researchers and practitioners across various fields. In many applications, it is common that only limited variables are observable. In this paper, we propose a method for parameter inference of a system of nonlinear coupled ordinary differential equations with partial observations. Our method combines fast Gaussian process-based gradient matching and deterministic optimization algorithms. By using initial values obtained by Bayesian steps with low sampling numbers, our deterministic optimization algorithm is both accurate, robust and efficient with partial observations and large noise.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1098/rsos.210171DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8316824PMC
July 2021

Multisystem Inflammatory Syndrome in Children (MIS-C) Associated with COVID-19 Infection.

Indian J Pediatr 2021 10 16;88(10):1053. Epub 2021 Jul 16.

Department of Pediatrics, Asian Institute of Medical Sciences Faridabad, Haryana, 121001, India.

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s12098-021-03832-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8284036PMC
October 2021

Biological Synthesis of PbS, AsS, HgS, CdS Nanoparticles using Pseudomonas aeruginosa and their Structural, Morphological, Photoluminescence as well as Whole Cell Protein Profiling Studies.

J Fluoresc 2021 Sep 15;31(5):1445-1459. Epub 2021 Jul 15.

Laboratorio Nacional de Micro Y Nanofluidica (LABMyN), Centro de Investigación y Desarrollo Tecnológico en Electroquímica (CIDETEQ), Queretaro, 76703, México.

Metal sulfide nanoparticles are semi-conductors that possess many applications in optics, optoelectronics and magnetic devices. There are physical and chemical methods for their synthesis but such methods involve toxic precursors as well as many obnoxious by-products. Hence, biological synthesis of metal sulfide nanoparticles are efficient enough to transform toxic metals to non-toxic ones. Pseudomonas aeruginosa, isolated from textile effluent and tolerant of high levels of heavy metals, was used for the green synthesis of metal sulfide (HgS, AsS, CdS and PbS) nanoparticles. The optical, structural and morphological nature of metal sulfide nanoparticles was also determined. FTIR (Fourier Transform Infra-red) analysis showed spectral changes when P. aeruginosa was grown in medium containing heavy metals viz. Hg, As, Pb and Cd indicating that there are functional groups viz. carboxyl, hydroxyl, phosphate, amino and amide, that exists on the surface of the bacteria, thus facilitating binding of metals on its surface. The bacterial samples which were treated with different metals at different concentrations, were subjected to whole cell protein analysis using SDS-PAGE (Sodium dodecyl Sulphate- Polyacrylamide gel electrophoresis) and protein profiling. The total protein estimation revealed that there was an increase in the protein concentration in the presence of heavy metals and a significant change in the banding pattern was observed which showed induction of a set of proteins under heavy metal stress especially mercury.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s10895-021-02769-2DOI Listing
September 2021

Spatial network based model forecasting transmission and control of COVID-19.

Physica A 2021 Nov 1;581:126223. Epub 2021 Jul 1.

Department of Mathematics, Indian Institute of Technology, Ropar 140001, India.

The SARS-CoV-2 driven infectious novel coronavirus disease (COVID-19) has been declared a pandemic by its brutal impact on the world in terms of loss on human life, health, economy, and other crucial resources. To explore more about its aspects, we adopted the (Susceptible-Exposed-Infected-Recovered-Death) pandemic spread with a time delay on the heterogeneous population and geography in this work. Focusing on the spatial heterogeneity, epidemic spread on the framework of modeling that incorporates population movement within and across the boundaries is studied. The entire population of interest in a region is divided into small distinct geographical sub regions, which interact using migration networks across boundaries. Utilizing the time delay differential equations based model estimations, we analyzed the spread dynamics of disease in India. The numerical outcomes from the model are validated using real time available data for COVID-19 cases. Based on the developed model in the framework of the recent data, we verified total infection cases in India considering the effect of nationwide lockdown at the onset of the pandemic and its unlocking by what seemed to be the end of the first wave. We have forecasted the total number of infection cases in two extreme situations of nationwide no lockdown and strict lockdown scenario. We expect that in future for any change in the key parameters, due to the regional differences, predictions will lie within the bounds of the above mentioned extreme plots. We computed the approximate peak infection in forwarding time and relative timespan when disease outspread halts. The most crucial parameter, the time-dependent generalization of the basic reproduction number, has been estimated. The impact of the social distancing and restricted movement measures that are crucial to contain the pandemic spread has been extensively studied by considering no lockdown scenario. Our model suggests that attaining a reduction in the contact rate between susceptible and infected individuals by practicing strict social distancing is one of the most effective control measures to manage COVID-19 spread in India. The cases can further decrease if social distancing is followed in conjunction with restricted movement.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.physa.2021.126223DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8247259PMC
November 2021

Network synchronization, stability and rhythmic processes in a diffusive mean-field coupled SEIR model.

Commun Nonlinear Sci Numer Simul 2021 Nov 15;102:105927. Epub 2021 Jun 15.

Department of Mathematics, Indian Institute of Technology Ropar, Rupnagar, 140001, Punjab, India.

Connectivity and rates of movement have profound effect on the persistence and extinction of infectious diseases. The emerging disease spread rapidly, due to the movement of infectious persons to some other regions, which has been witnessed in case of novel coronavirus disease 2019 (COVID-19). So, the networks and the epidemiology of directly transmitted infectious diseases are fundamentally linked. Motivated by the recent empirical evidence on the dispersal of infected individuals among the patches, we present the epidemic model SEIR (Susceptible-Exposed-Infected-Recovered) in which the population is divided into patches which form a network and the patches are connected through mean-field diffusive coupling. The corresponding unstable epidemiology classes will be synchronized and achieve stable state when the patches are coupled. Apart from synchronization and stability, the coupled model enables a range of rhythmic processes such as birhythmicity and rhythmogenesis which have not been investigated in epidemiology. The stability of Disease Free Equilibrium (or Endemic Equilibrium) is attained through cessation of oscillation mechanism namely Oscillation Death (OD) and Amplitude Death (AD). Corresponding to identical and non-identical epidemiology classes of patches, the different steady states are obtained and its transition is taking place through Hopf and transcritical bifurcation.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.cnsns.2021.105927DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8205286PMC
November 2021

Flame synthesis of carbon nanoparticles from corn oil as a highly effective cationic dye adsorbent.

Chemosphere 2021 Nov 1;282:131062. Epub 2021 Jun 1.

Department of Chemical Engineering, University of Waterloo, Waterloo, ON, Canada; Institute of Polymer Research, University of Waterloo, Waterloo, ON, Canada; Waterloo Institute for Nanotechnology, University of Waterloo, Waterloo, ON, Canada. Electronic address:

Carbon nanoparticles (CNP) were synthesized through flame deposition method from a sustainable corn oil precursor. The morphology, particle size, surface chemistry, thermal stability, and zeta potential of the CNP were characterized. The batch adsorption of a cationic dye, methylene blue (MB), by the CNP at various concentrations, pH, and temperatures was evaluated to investigate the CNP's efficacy in industrial wastewater treatment applications. Results revealed the excellent adsorption of MB onto the CNP. The experimental data were then fitted into isotherm models, kinetic models, and thermodynamic models, and the model parameters, constants, Gibb free energy, enthalpy, and entropy were calculated and discussed. Hydrogen bonding and strong electrostatic interaction were the main adsorption mechanism for MB adsorption by the CNP. The CNP exhibited a maximum adsorption capacity of 138.89 mg/g, indicating superior adsorption of MB dye without the need for any further purification and activation steps. The adsorption efficiency did not compromise as the solution temperature increased up to 60 °C, and it can further be enhanced under alkaline conditions. To simulate the practical and industrial use of the developed CNP in textile effluent treatment, successful experiments were conducted in continuous flow adsorption by allowing concentrated MB solution to flow through a designed fixed bed purification system with a CNP filter bed.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.chemosphere.2021.131062DOI Listing
November 2021

Symmetry of three-center, four-electron bonds.

Chem Sci 2020 Jun 30;11(30):7979-7990. Epub 2020 Jun 30.

Department of Chemistry - BMC, Uppsala University Husargatan 3 Uppsala 752 37 Sweden

Three-center, four-electron bonds provide unusually strong interactions; however, their nature remains ununderstood. Investigations of the strength, symmetry and the covalent electrostatic character of three-center hydrogen bonds have vastly contributed to the understanding of chemical bonding, whereas the assessments of the analogous three-center halogen, chalcogen, tetrel and metallic [small sigma, Greek, circumflex]-type long bonding are still lagging behind. Herein, we disclose the X-ray crystallographic, NMR spectroscopic and computational investigation of three-center, four-electron [D-X-D] bonding for a variety of cations (X = H, Li, Na, F, Cl, Br, I, Ag and Au) using a benchmark bidentate model system. Formation of a three-center bond, [D-X-D] is accompanied by an at least 30% shortening of the D-X bonds. We introduce a numerical index that correlates symmetry to the ionic size and the electron affinity of the central cation, X. Providing an improved understanding of the fundamental factors determining bond symmetry on a comprehensive level is expected to facilitate future developments and applications of secondary bonding and hypervalent chemistry.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1039/d0sc02076aDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8163095PMC
June 2020

[Cu{SC(O)OPr}]: A Giant Self-Assembled Copper(I) Supramolecular Wheel Exhibiting Photoluminescence Tuning and Correlations with Dynamic Solvation and Solventless Synthesis.

Inorg Chem 2021 Jun 3;60(12):8973-8983. Epub 2021 Jun 3.

Department of Chemistry, National Dong Hwa University, Hualien 974301, Taiwan R.O.C.

The hierarchical self-organization of structurally complex high-nuclearity metal clusters with metallosupramolecular wheel architectures that are obtained from the self-assembly of smaller solvated cluster units is rare and unique. Here, we use the potentially heteroditopic monothiocarbonate ligand and demonstrate for the first time the synthesis and structure of a solvated non-cyclic hexadecanuclear cluster [Cu{SC(O)OPr}]·2THF () that can simultaneously desolvate and self-assemble in solution and subsequently form a giant metallaring, [Cu{SC(O)OPr}] (). We also demonstrate a luminescent precursor to cluster () can be achieved through a solventless and rapid mechanochemical synthesis. Cluster () is the highest nuclearity copper(I) wheel and the largest metal cluster containing a heterodichalcogen (O, S) ligand reported to date. Cluster () also exhibits solid-state luminescence with relatively long emission lifetimes at 4.1, 13.9 (μs). The synthetic strategy described here opens new research avenues by replacing solvent molecules in stable {Cu} clusters with designed building units that can form new hybrid and multifunctional finite supramolecular materials. This finding may lead to the development of novel high-nuclearity materials self-assembled in a facile manner with tunable optical properties.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/acs.inorgchem.1c00871DOI Listing
June 2021

Post-COVID Syndrome (MIS-C) with Refractory Status Epilepticus.

Indian J Pediatr 2021 07 21;88(7):721. Epub 2021 Apr 21.

Department of Pediatrics, Asian Institute of Medical Sciences, Faridabad, Delhi NCR, 121001, India.

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s12098-021-03731-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8057941PMC
July 2021

Platelet Indices show marked systematic bias on storage under ideal conditions: An important preanalytical factor affecting the interpretation of platelet indices.

Asian J Transfus Sci 2020 Jul-Dec;14(2):208-209. Epub 2020 Dec 19.

Department of Pathology and Laboratory Medicine, All India Institute of Medical Sciences, Rishikesh, Uttarakhand, India.

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.4103/ajts.AJTS_51_19DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7983132PMC
December 2020

Alternative Strategy Adopted in Practical Assessment for Pathology Postgraduate Certification Examination Amidst COVID-19 Nationwide Lockdown: An Indian Experience with a Novel Hybrid Method of Assessment.

Adv Med Educ Pract 2021 8;12:1-9. Epub 2021 Jan 8.

Department of Physiology & Advanced Center of Continuous Professional Development, All India Institute of Medical Sciences, Rishikesh, Uttarakhand, India.

Background: A major concern and challenge faced by the educational institution during coronavirus disease (COVID-19) pandemic and consequent lockdown is the timely conduct of the summative assessment. Unlike cognitive assessment, real-time practical assessment through online mode, without compromising principles of assessment is difficult. This study was performed to analyze an alternative hybrid approach adopted for the postgraduate practical summative assessment in pathology.

Materials And Methods: Evaluation of the process of summative assessment was done where internal and external examiners synchronously assessed examinees real-time on-site (face to face) and off-site (remotely through live videoconferencing) respectively. A pre-validated questionnaire on a novel approach for assessment and feedback (with close-ended on 5-point Likert scale and open-ended questions) were administered to nine participants comprising three final year postgraduates in pathology, four examiners (two internal and two externals) and two technical experts from the Department of Pathology. Overall scores obtained by all examinees were recorded. A pre-validated questionnaire and feedback were administered to the participants to assess the novel approach to assessment.

Results: The mean performance score obtained by examinees was 63.5% in the summative assessment. Feedback analysis revealed that 85% of participants strongly agreed and the rest (15%) agreed that essential minor deviations introduced in this novel mode of assessment did not compromise basic principles and goals of assessment. Quality of assessment through this mode of assessment was graded as good to excellent. All participants responded that this mode of examination may be applied in the future under similar circumstances.

Conclusion: This study concludes that an alternative novel hybrid method of real-time synchronous assessment with on-site and off-site examiners may be a feasible and successful model for conducting summative assessment and can be practiced in time of need.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.2147/AMEP.S286423DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7802903PMC
January 2021

Antibacterial and cytotoxic prenylated dihydrochalcones from Eriosema montanum.

Fitoterapia 2021 Mar 11;149:104809. Epub 2021 Jan 11.

Department of Chemistry - BMC, Uppsala University, SE-751 23 Uppsala, Sweden. Electronic address:

Two new prenylated dihydrochalcones (1,2) and eighteen known secondary metabolites (3-20) were isolated from the CHCl-MeOH (1:1) extracts of the roots, the stem bark and the leaves of Eriosema montanum Baker f. (Leguminosae). The structures of the isolated compounds were characterized by NMR, IR, and UV spectroscopic and mass spectrometric analyses. The structures of compounds 5, 10, 11 and 13 were confirmed by single crystal X-ray diffraction. The antibacterial activity of the crude extracts and the isolated constituents were established against Gram-positive and Gram-negative bacteria. Among the tested compounds, 1-4 and 10 showed strong activity against the Gram-positive bacterium Bacillus subtilis with minimum inhibitory concentration (MIC) ranging from 3.1 to 8.9 μM, as did the leaf crude extract with an MIC of 3.0 μg/mL. None of the crude extracts nor the isolated compounds were active against Escherichia coli. Compounds 1, 3 and 4 showed higher cytotoxicity, evaluated against the human breast cancer cell line MCF-7, with EC of 7.0, 18.0 and 18.0 μM, respectively. These findings contribute to the phytochemical understanding of the genus Eriosema, and highlight the pharmaceutical potential of prenylated dihydrochalcones.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.fitote.2020.104809DOI Listing
March 2021

Electronic and geometric structure effects on one-electron oxidation of first-row transition metals in the same ligand framework.

Dalton Trans 2021 Jan 16;50(2):660-674. Epub 2020 Dec 16.

Molecular Biomimetics, Department of Chemistry -Ångström Laboratory, Uppsala University, 75120 Uppsala, Sweden.

Developing new transition metal catalysts requires understanding of how both metal and ligand properties determine reactivity. Since metal complexes bearing ligands of the Py5 family (2,6-bis-[(2-pyridyl)methyl]pyridine) have been employed in many fields in the past 20 years, we set out here to understand their redox properties by studying a series of base metal ions (M = Mn, Fe, Co, and Ni) within the Py5OH (pyridine-2,6-diylbis[di-(pyridin-2-yl)methanol]) variant. Both reduced (M) and the one-electron oxidized (M) species were carefully characterized using a combination of X-ray crystallography, X-ray absorption spectroscopy, cyclic voltammetry, and density-functional theory calculations. The observed metal-ligand interactions and electrochemical properties do not always follow consistent trends along the periodic table. We demonstrate that this observation cannot be explained by only considering orbital and geometric relaxation, and that spin multiplicity changes needed to be included into the DFT calculations to reproduce and understand these trends. In addition, exchange reactions of the sixth ligand coordinated to the metal, were analysed. Finally, by including published data of the extensively characterised Py5OMe (pyridine-2,6-diylbis[di-(pyridin-2-yl)methoxymethane])complexes, the special characteristics of the less common Py5OH ligand were extracted. This comparison highlights the non-innocent effect of the distal OH functionalization on the geometry, and consequently on the electronic structure of the metal complexes. Together, this gives a complete analysis of metal and ligand degrees of freedom for these base metal complexes, while also providing general insights into how to control electrochemical processes of transition metal complexes.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1039/d0dt03695aDOI Listing
January 2021

Luminol-Based Turn-On Fluorescent Sensor for Selective and Sensitive Detection of Sulfur Mustard at Ambient Temperature.

Anal Chem 2021 01 8;93(2):1193-1199. Epub 2020 Dec 8.

Defence Research and Development Establishment, Jhansi Road, Gwalior 474002, India.

We have explored a novel turn-on fluorescence detection of sulfur mustard (SM) at "room temperature". The innovative protocol that uses the combination of luminol and an ionic liquid in water exhibits fluorescence detection of SM within seconds. In this simple, fast, and low-cost chemosensing method, luminol acts as the receptor as well as a signaling element, and the ionic liquid (1-ethyl-3-methylimidazolium dicyanamide) provides the requisite and polarizing medium to realize the detection at "room temperature". Interestingly, with a higher concentration of a probe (0.56 mM), SM sensing can be visualized with the naked eye, leading to the formation of a fluorescent green color within a minute, thus expanding the application of the developed sensing technique for chromo-fluorogenic detection of SM. Excellent selectivity, sensitivity (LOD: 6 ppm), and chemosensing at ambient temperature make this methodology completely field-deployable.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/acs.analchem.0c04464DOI Listing
January 2021

Evaluation of platelet distribution width as novel biomarker in gall bladder cancer.

J Carcinog 2020 27;19. Epub 2020 Jun 27.

Department of Surgery, All India Institute of Medical Sciences, Rishikesh, Uttarakhand, India.

Introduction: Gall bladder cancer (GBC) tends to present in advanced stages, therefore, early diagnosis of GBC is necessary. There is no ideal single tumor marker available presently for the diagnosis and prognosis of GBC. Platelet distribution width (PDW) is an early marker for activated platelets and has been used in a variety of tumors to assess prognosis. This study was designed to evaluate the utility of PDW in identifying GBC patients and its association with tumor markers, staging and resectability of GBC.

Materials And Methods: This cross sectional study was done on 100 patients of GBC and 100 age- and sex- matched healthy controls. PDW was evaluated and compared between GBC and healthy controls. Receiver-operating characteristics was plotted to determine optimal cut-off for identifying GBC patients and to determine sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of PDW. Correlation between serum tumor markers (carbohydrate antigen 19-9, carcinoembryonic antigen, and carbohydrate antigen 125) and PDW were evaluated. Association of PDW with hyperbilirubinemia, staging and resectability of GBC was also studied.

Results: A significantly higher PDW with a median of 18.1 was observed in GBC as compared to healthy controls with median value of 13. PDW was found to have a very high sensitivity (90%), specificity (95%), PPV (94%) and NPV (90%) in identifying GBC at cut-off of 16 with area under the curve (AUC) of 0.97. An increase of PDW was observed with increasing stage and unresectable GBC. However, it was not statistically significant. Significant positive correlation was observed between PDW and all three serum tumor markers and good positive correlation with = 0.61 was observed with CA 19-9.

Conclusion: PDW was associated with GBC and may be considered as a cost- effective marker in adjunct to other investigations for the diagnosis of GBC.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.4103/jcar.JCar_12_20DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7511895PMC
June 2020

Short-term biological variation of differential count in healthy subjects in a South Asian population.

Scand J Clin Lab Invest 2020 Dec 5;80(8):654-658. Epub 2020 Oct 5.

Department of Pathology & Laboratory Medicine, All India Institute of Medical Sciences, Rishikesh, India.

Estimates of Within-Subject and between subject biological variation for the white blood cell differential count (DC) have not been reported in South Asia. Therefore, we attempted to measure the short-term biological variation estimates for DC. The study was conducted on 28 healthy volunteers (15 males and 13 females). Blood from the volunteers was collected in the morning in K3-EDTA vials and analyzed in triplicate on the Sysmex XN-1000 analyzer, for six consecutive days. The Within subject, between subject and analytical coefficient of variation of the DC was calculated from the results by nested repeated measures ANOVA after outlier exclusion. The Reference change values (RCV) were also calculated. The within-subject variation for eosinophil Count and between subject variation for basophils in our study from South Asia was greater than the published European and American studies. Males and females showed similar biological variation for DC. The within-subject variation of other parameters (Neutrophils, Lymphocytes, Monocytes and Basophils) were similar or showed only mild differences to the published studies. The markedly different within-subject variation for Eosinophil counts suggest that the RCV for DC in South Asians need to be different from the published data in order to have clinical relevance. The Within-subject variation values of the other parameters seem transportable from the published European and American studies, but the small differences found mean that further regional estimates need to be reported for robust evidence of the same.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1080/00365513.2020.1827290DOI Listing
December 2020

Clinical and Imaging Manifestations of Trochlear Nerve Schwannomas-A Case Series.

J Neuroophthalmol 2021 Sep;41(3):e339-e342

Department of Opthalmology, Counties Manukau DHB and Auckland DHB (AG), Auckland, New Zealand; Department of Diagnostic Radiology, SingHealth Institution (ELCH, RCC), Singapore; Massachusetts Eye and Ear (HRK), Boston, Massachusetts; Department of Diagnostic Radiology, Massachusetts General Hospital (HRK), Harvard Medical School, Boston, Massachusetts; and Duke Medical School (RCC), Singapore.

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1097/WNO.0000000000001059DOI Listing
September 2021

Golden Age of Fluorenylidene Phosphaalkenes-Synthesis, Structures, and Optical Properties of Heteroaromatic Derivatives and Their Gold Complexes.

J Org Chem 2020 Nov 4;85(22):14619-14626. Epub 2020 Sep 4.

Synthetic Molecular Chemistry, Department of Chemistry - Ångström Laboratories, Uppsala University, Box 523, 75120 Uppsala, Sweden.

The substitution of 2,7-dibromo-9-fluorenyl phosphaalkenes with heteroaromatic substituents (bithiophene, benzothiophene, pyridine) offers access to interesting push-pull dye molecules. Steric shielding due to the bulky P-substituent gives marked different reactivities at the 2- and 7-positions, allowing the synthesis of mixed/asymmetric derivatives. Further functionalization via gold(I) coordination was demonstrated and increased the acceptor character, concomitant with a red-shifted absorption.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/acs.joc.0c01336DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7684575PMC
November 2020

Role of Reticulocyte Parameters in Anemia of First Trimester Pregnancy: A Single Center Observational Study.

J Lab Physicians 2020 Mar 15;12(1):15-19. Epub 2020 Jun 15.

Department of Obstetrics and Gynecology, All India Institute of Medical Sciences, Rishikesh, Uttarakhand, India.

 The diagnosis of anemia in pregnancy should be early to prevent complications to mother and baby. It should be simple and safe, and therefore feasibility of reticulocyte parameters may prove beneficial in this regard. Newer reticulocyte parameters have not been studied extensively especially in pregnancy. The present study was conducted to evaluate reticulocyte hemoglobin content (Ret-He), immature reticulocyte fraction, and reticulocyte count and to compare them with serum ferritin, mean corpuscular volume (MCV), and mean corpuscular hemoglobin (MCH) in assessment anemia in pregnancy.  Prospective study included first trimester pregnant females where hemoglobin, MCV, and MCH were categorized and statistically analyzed with serum ferritin and reticulocyte parameters.  The study included 155 first trimester pregnant females showing statistical difference in Ret-He between all categories of hemoglobin and MCV ( < 0.05). ROC curve analysis using MCV < 83 fl and MCH <27 pg showed that area under curve for Ret-He at cutoff of 27.8 ng/mL was 0.93 (95% confidence interval 0.90-0.98, sensitivity 93%, specificity 83%). The cutoff of 27.2 ng/mL Ret-He for the diagnosis of iron deficiency anemia has specificity of 86%, sensitivity 71%, positive predictive value 0.39, and likelihood ratio of 5.1.  Ret-He is a feasible and easily available parameter which may be helpful in differentiating between microcytic hypochromic and normocytic normochromic anemia along with frank and borderline anemia in first trimester pregnant females. This in turn is essential to initiate an early therapy so as to prevent the maternal and fetal complications.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1055/s-0040-1713585DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7419173PMC
March 2020
-->