Population Densities Of States Research Articles

Influence of helium metastable states on the E-H mode transition in an inductively coupled plasma

A helium (He) inductively coupled plasma (ICP) source combined with two diode laser systems with the wavelengths of 396.5 nm (21S–41P) and 1082.9 nm (23S–23P) was configured to investigate the influence of He metastable states on the E-H mode transition. The population densities of 21S and 23S states were measured by laser absorption spectroscopy as the functions of RF power, He pressure, and the distance from RF antenna. Correlations between the E-H mode transition and the population density ratio of the 23S metastable state to the 21S metastable state as well as the line intensity ratio (LIR) of the 33D-23S transition to the 31P–21S transition were investigated. The E-H mode transition of He ICP was analyzed by the electron impact ionization rate and it was confirmed that the 23S metastable state plays a key role in the E-H mode transition.

On the population density of the argon excited levels in a high power impulse magnetron sputtering discharge

Population densities of excited states of argon atoms in a high power impulse magnetron sputtering (HiPIMS) discharge are examined using a global discharge model and a collisional-radiative model. Here, the ionization region model (IRM) and the Orsay Boltzmann equation for electrons coupled with ionization and excited states kinetics (OBELIX) model are combined to obtain the population densities of the excited levels of the argon atom in a HiPIMS discharge. The IRM is a global plasma chemistry model based on particle and energy conservation of HiPIMS discharges. OBELIX is a collisional-radiative model where the electron energy distribution is calculated self-consistently from an isotropic Boltzmann equation. The collisional model constitutes 65 individual and effective excited levels of the argon atom. We demonstrate that the reduced population density of high-lying excited argon states scales with (p*)−6, where p* is the effective quantum number, indicating the presence of a multistep ladder-like excitation scheme, also called an excitation saturation. The reason for this is the dominance of electron impact processes in the population and de-population of high-lying argon states in combination with a negligible electron–ion recombination.

TDOS/PDOS/OPDOS, reduced density gradient (RDG) and molecular docking studies of [3-(3-bromophenyl)-cis-4,5-dihydroisoxazole-4,5-diyl]bis(methylene) diacetate

Due to the wide range of biological activity, 4,5-dihydroisoxazole compounds form an important family of five-membered heterocycles containing an oxygen atom and a nitrogen atom in the adjacent position. Therefore, [3- (3-bromophenyl) -cis-4,5-dihydroisoxazol-4,5-yl] bis (methylene) diacetate [BDBD] compound, which is a derivative of 4,5-dihydroisoxazole, was investigated in this study. The partial density of state (PDOS), the overlap population density of state (OPDOS) and total density of state (TDOS) of functional groups of the [BDBD] compound were theoretically evaluated using the DFT / B3LYP / 6-311G (d, p) method. Reduced density gradient (RDG) was also given to study the weak interaction, strong attraction, and strong repulsion interactions of the studied molecule. The PASS (Prediction of Activity Spectra) analysis predicts the carcinogenic activities with probability to be active value of 0.273 for the studied molecule. The antibacterial and anti-inflammatory activities of the [BDBD] compound against various the HIV-1 protease (1HSG), GyrB ATPase (3U2D), and VEGFR-2 kinase enzyme (4AG8) proteins were studied using molecular docking. The binding energies of 1HSG, 3U2D, and 4AG8 target proteins with [BDBD] ligand were calculated to be -6.11, -4.54, and -4.80 kcal/mol, respectively. Results were interpreted by comparing with the literature.

Molecular Docking and Quantum Chemical Computations of 4-Chloro-2-[(furan-2-ylmethyl)amino]-5-sulfamoylbenzoic Acid Based on Density Functional Theory

Quantum computational calculations of energies and geometries of 4-chloro-2-[(furan-2-ylmethyl)amino]-5-sulfamoylbenzoic acid have been performed by DFT level of theory using B3LYP/6-31G(d,p) basis set. The solid phase FT-Raman and FT-IR spectra of the Furosemide compound were recorded in the region 4000 cm−1 to 400 cm−1 and 4000 cm−1 to 400 cm−1 respectively. The molecular geometry, harmonic vibrational frequencies and bonding features of 4-chloro-2-[(furan-2-ylmethyl)amino]-5-sulfamoylbenzoic acid in the ground state have been calculated by using density functional theory (DFT) B3LYP method with standard 6–31 G(d,p) basis set. The scaled theoretical wavenumber showed very good agreement with the experimental values. The vibrational assignments were performed on the basis of the total energy distribution (TED) of the vibrational modes. Stability associated with molecule as a result of hyperconjugative interactions, charge delocalization has been analyzed utilizing Natural Bond Orbital (NBO) analysis through the use of B3LYP/6-31G(d,p) technique. The outcomes reveal that electron density (ED) within the σ* and π* orbitals which are antibonding second-order delocalization energies E (2) confirm the occurrence of intramolecular charge transfer (ICT) inside the molecule. Hirshfield surface analysis and Fukui functions calculation were also performed. From the calculations the first order hyperpolarisability was found to be 3.136 × 10−30esu. The molecule orbital contributions have been analyzed utilizing the total (TDOS), partial (PDOS), and overlap population (OPDOS) density of states. A molecular docking study has supported the anticonvulsant activity of the Furosemide molecule.

Machine Learning Models of COVID-19 Cases in the United States: A Study of Initial Lockdown and Reopen Regimes

The purpose of this paper is to model the cases of COVID-19 in the United States from 13 March 2020 to 31 May 2020. Our novel contribution is that we have obtained highly accurate models focused on two different regimes, lockdown and reopen, modeling each regime separately. The predictor variables include aggregated individual movement as well as state population density, health rank, climate temperature, and political color. We apply a variety of machine learning methods to each regime: Multiple Regression, Ridge Regression, Elastic Net Regression, Generalized Additive Model, Gradient Boosted Machine, Regression Tree, Neural Network, and Random Forest. We discover that Gradient Boosted Machines are the most accurate in both regimes. The best models achieve a variance explained of 95.2% in the lockdown regime and 99.2% in the reopen regime. We describe the influence of the predictor variables as they change from regime to regime. Notably, we identify individual person movement, as tracked by GPS data, to be an important predictor variable. We conclude that government lockdowns are an extremely important de-densification strategy. Implications and questions for future research are discussed.

Governor's Party, Policies, and COVID-19 Outcomes: Further Evidence of an Effect

IntroductionThis study connects the aggregate strength of public health policies taken in response to the COVID-19 pandemic in the U.S. states to the governors’ party affiliations and to state-level outcomes. Understanding the relationship between politics and public health measures can better prepare American communities for what to expect from their governments in a future crisis and encourage advocacy for delegating public health decisions to medical professionals.MethodsThe public health Protective Policy Index captures the strength of policy response to COVID-19 at the state level. The authors estimated a Bayesian model that links the rate of disease spread to Protective Policy Index. The model also accounted for the possible state-specific undercounting of cases and controls for state population density, poverty, number of physicians, cardiovascular disease, asthma, smoking, obesity, age, racial composition, and urbanization. A Bayesian linear model with natural splines of time was employed to link the dynamics of Protective Policy Index to governors’ party affiliations.ResultsA 10–percentage point decrease in Protective Policy Index was associated with an 8% increase in the expected number of new cases. Between late March and November 2020 and at the state-specific peaks of the pandemic, the Protective Policy Index in the states with Democratic governors was about 10‒percentage points higher than in the states with Republican governors.ConclusionsPublic health measures were stricter in the Democrat-led states, and stricter public health measures were associated with a slower growth of COVID-19 cases. The apparent politicization of public health measures suggests that public health decision making by health professionals rather than by political incumbents could be beneficial.

Reservoir ecological operation by quantifying outflow disturbance to aquatic community dynamics

Reservoir operation causes spatiotemporal variations in outflow, which influence the dynamics of downstream aquatic communities. However, empirical evidence of community responses to hydrological alteration remains limited for dam-regulated rivers. This study focused on quantifying the streamflow disturbance to multi-population dynamics in downstream of the China’s Danjiangkou Reservoir. First, the stochastic population dynamics model (PDM) was used to simulate aquatic community dynamics. Then, the flow–ecology relationship was established to identify community response to reservoir outflow. Third, two novel ecological indicators, stable time (ST) and coefficient of variation at stable time (CVST), were proposed to evaluate the resilience and resistance of multi-population systems, respectively. Finally, the reservoir operating rule curves were optimized by considering tradeoffs between socioeconomic and ecological objectives. The coevolution processes of multi-population systems (fish, phytoplankton, zooplankton, zoobenthos, and macrophytes) were simulated by stochastic PDMs. The population densities of stable states showed continuous downward trends with increasing degree of hydrological alteration for multi-population systems, and aquatic community systems could be destroyed when alteration reached its acceptable maximum. The greater the degree of hydrological alteration, the longer the recovery time from an unstable to a stable state, and the weaker resistance for each population system. The resilience and resistance of downstream multi-population systems were enhanced by optimizing reservoir outflow. The optimization results illustrated that the performances of the multiple objectives of water supply, hydropower generation, and ST were improved by 2.37%, 2.40%, and 2.67%, respectively, whereas the performance of CVST was the same as the conventional operation. The flow–ecology relationship provided an approach to quantify the impacts of reservoir outflow on an aquatic community, which is helpful in guiding ecological flow strategies.

Study on the bonding properties of ZrB2 (0001)/ZrC (111) interface via first-principles calculations

The bonding properties of ZrB2 (0001)/ZrC (111) interfaces were studied via the method of first-principles calculations. Firstly, eight kinds of interfaces with different terminations and stacking sequences were constructed. Then, bonding strength of interface was evaluated by work of separation (Wsep). It is found that ZrB2 B-terminated/ZrC Zr-terminated and ZrB2 Zr-terminated/ZrC C-terminated interfaces have very large Wsep values of 9.12 J/m2 and 10.06 J/m2. The natures of bonds were analyzed through the methods of charge density difference, Mulliken population and partial density of states. The results show that B–Zr and Zr–C bonds formed at interface are mainly ionic, and also with some content of covalent, which are similar to the B–Zr and Zr–C bonds inside the bulk ZrB2 and ZrC. The strong B–Zr and Zr–C bonds contribute to the high bonding strength of ZrB2/ZrC interface.

Theoretical studies on the catalytic hydrogenation of carbon dioxide by 3d transition metals single-atom catalyst supported on covalent triazine frameworks

• The co-adsorption configuration of hydrogen and CO 2 on the unsaturated coordination single-atom catalysts (SACs) gives it a unique selectivity for CO 2 hydrogenation to formic acid. • A ‘volcano’ plot was established between the 3d-orbital electron number and barrier energy, in which Ni appeared at the summit. • Part of the overlap population density of states (OPDOS) of Ni and H atom is located in unoccupied orbitals, resulting in a weak Ni H bond. • Inert intermediates lead to low activity of Sc, Ti, V. The catalytic conversion of carbon dioxide (CO 2 ) into value-added products is a significant emission reduction method. Among numerous catalysts, single-atom catalysts (SACs) show great potential in CO 2 hydrogenation. However, it is difficult to predict the CO 2 hydrogenation products because the SACs consisting of the same metal and different supports commonly show various catalytic selectivity. Here we study the catalytic mechanism of the CO 2 hydrogenation process catalyzed by the SAC with 3d transition metals. The metal atoms are anchored on the covalent triazine frameworks (CTFs). We find the correlation between adsorption configuration and the selectivity of the CO 2 hydrogenation. The coadsorption configuration of the H atom and CO 2 molecule is favorable to forming the C H bond in formate. A volcano relation based on activation barrier and 3d-orbital electron numbers was obtained. We found that the catalyst with Ni metal has the lowest activation barrier. We also explained the low catalytic activity of Sc, Ti, and V metals due to the inert intermediates occupying the active sites. This work may be helpful to design highly selective and highly active catalysts in CO 2 hydrogenation.

Associations Between Governor Political Affiliation and COVID-19 Cases, Deaths, and Testing in the U.S.

IntroductionThe response to the COVID-19 pandemic became increasingly politicized in the U.S., and the political affiliation of state leaders may contribute to policies affecting the spread of the disease. This study examines the differences in COVID-19 infection, death, and testing by governor party affiliation across the 50 U.S. states and the District of Columbia.MethodsA longitudinal analysis was conducted in December 2020 examining COVID-19 incidence, death, testing, and test positivity rates from March 15, 2020 through December 15, 2020. A Bayesian negative binomial model was fit to estimate the daily risk ratios and posterior intervals comparing rates by gubernatorial party affiliation. The analyses adjusted for state population density, rurality, Census region, age, race, ethnicity, poverty, number of physicians, obesity, cardiovascular disease, asthma, smoking, and presidential voting in 2020.ResultsFrom March 2020 to early June 2020, Republican-led states had lower COVID-19 incidence rates than Democratic-led states. On June 3, 2020, the association reversed, and Republican-led states had a higher incidence (risk ratio=1.10, 95% posterior interval=1.01, 1.18). This trend persisted through early December 2020. For death rates, Republican-led states had lower rates early in the pandemic but higher rates from July 4, 2020 (risk ratio=1.18, 95% posterior interval=1.02, 1.31) through mid-December 2020. Republican-led states had higher test positivity rates starting on May 30, 2020 (risk ratio=1.70, 95% posterior interval=1.66, 1.73) and lower testing rates by September 30, 2020 (risk ratio=0.95, 95% posterior interval=0.90, 0.98).ConclusionsGubernatorial party affiliation may drive policy decisions that impact COVID-19 infections and deaths across the U.S. Future policy decisions should be guided by public health considerations rather than by political ideology.

Probing the structural properties, binding mode and intermolecular interactions of herbacetin against H1N1 neuraminidase using vibrational spectroscopic, quantum chemical calculation and molecular docking studies

Herbacetin (HBN) is an antiviral agent of H1N1 influenza virus which was reported to inhibit H1N1 neuraminidase (NA) enzyme with IC50 value of 8.9 μM. The research exploration for HBN was conducted via quantum chemical calculations and spectroscopic techniques. The experimental vibrational FT-IR and FT-Raman spectra of the HBN molecule were obtained, and it was compared with theoretical method utilizing quantum chemical calculations through DFT approach employing basis sets 6-31G(d,p) and 6-311G(d,p). The MEP, NBO, global and local reactivity descriptors were carried out to describe the reactivity, selectivity and stabilization of the HBN molecule. The electronic characteristics namely UV-Vis and HOMO-LUMO were computed through TD-DFT method which was correlated with experimental spectral analysis. The total, partial and overlap population density of states (DOS) were carried out to confirm the molecular orbital contributions. The drug likeness and ADMET predictions were analysed to reveal the biological behaviour of the HBN. Furthermore, the molecular docking investigation is to find the best fit orientation: binding mode, inhibition constant and intermolecular interactions among HBN and NA enzyme. The ligand molecule fits very well in the NA active site cavity. Hence, the HBN molecule exhibits good biological activity, and it can be served as a prospective drug for H1N1 influenza A virus.

Mask...

Background: COVID-19 pandemic mitigation requires evidence-based strategies. Because COVID-19 can spread via respired droplets, most US states mandated mask use in public settings. Randomized control trials have not clearly demonstrated mask efficacy against respiratory viruses, and observational studies conflict on whether mask use predicts lower infection rates. We hypothesized that statewide mask mandates and mask use were associated with lower COVID-19 case growth rates in the United States. Methods: We calculated total COVID-19 case growth and mask use for the continental United States with data from the Centers for Disease Control and Prevention and Institute for Health Metrics and Evaluation. We estimated post-mask mandate case growth in non-mandate states using median issuance dates of neighboring states with mandates. Results: Earlier mask mandates were not associated with lower total cases or lower maximum growth rates. Earlier mandates were weakly associated with lower minimum COVID-19 growth rates. Mask use predicted lower minimum but not lower maximum growth rates. Growth rates and total growth were comparable between US states in the first and last mask use quintiles during the Fall-Winter wave. These observations persisted for both natural logarithmic and fold growth models and when adjusting for differences in US state population density. Conclusions: We did not observe association between mask mandates or use and reduced COVID-19 spread in US states. COVID-19 mitigation requires further research and use of existing efficacious strategies, most notably vaccination.

445. Correlative Factors for State to State Differences in the Prevalence and Case Fatality Rates of SARS-CoV-2, COVID-19 Infections in the United States of America

BackgroundIndividual States of the USA have ethnic, economic, community health and education differences that influence the prevalence and outcomes of COVID-19 infection. We hypothesized that Statewide differences in the prevalence and fatality rates of COVID-19 infections are dependent on factors that may be determined by mathematical modeling.MethodsTwo separate statistical regression models were developed using COVID-19 case prevalence and case fatality rates functioning as dependent variables. We obtained data from the prevalence and deaths from COVID-19 cases for each state in the USA that was posted at 4 PM Central Standard Time on April 29, 2020 from the Worldometer website. Publicly available databases were utilized to obtain data for the independent variables in the model.ResultsModels are represented as follows:Statewide COVID-19 Prevalence ModelLog (Statewide COVID_19 case prevalence) = 1.847* (100–250 individuals/mile2) +3.0025*(250+ individuals/mile2) + 1.021* (% African American population) +1.029* (% Hispanic American population +2.164 *(% adults aged 85+)Model results are shown in Table 1.Statewide COVID-19 Case Fatality Rate ModelLog (Statewide COVID_19 case fatality rate) =2.194* (100–250 individuals/mile2) +2.758* (250+ individuals/mile2) +1.031* (% African American population) + 1.032* (% Hispanic American population) + 0.942 (% Native American population)+ 1.108 (% Asian American population) + 2.275 (% adults aged 85+)Model results are shown in Table 2.Table 1: COVID-19 Statewide Prevalence Model Table 2: COVID-19 Statewide Case Fatality Model ConclusionHigher State population density (See Figure 1 and Figure 2) and higher State populations of elderly persons correspond to increased prevalence and case-fatality rates of COVID-19 infections. Statewide data also shows health disparities for COVID-19 infections in Hispanic Americans, African Americans, and Asian Americans. Paradoxically, States with larger populations of Native Americans who have known poor outcomes from COVID-19 infection demonstrate a decrease in case-fatality rates, suggesting a large effect of healthcare inequality in this population.Figure 1: ANOVA one-way analysis of the association between COVID-19 prevalence and population density Figure 2: ANOVA one-way analysis of the association between COVID-19 death prevalence and population density Disclosures Eli D. Ehrenpreis, MD, FACG, AGAF, E2Bio Consultants (Board Member, Chief Executive Officer)E2Bio Life Sciences (Shareholder, Chief Executive Officer)Level Ex, Inc. (Consultant)

Actinyl-Carboxylate Complexes [AnO2(COOH) n (H2O) m ]2-n (An = U, Np, Pu, and Am; n = 1-3; m = 0, 2, 4; 2n + m = 6): Electronic Structures, Interaction Features, and the Potential to Adsorbents toward Cs Ion.

Organic compounds of actinyls and their bonding features have attracted extensive attention in nuclear waste separation due to their characteristics of separating fission products. Herein, detailed studies on the binding sites of [AnO2(COOH)n(H2O)m]2–n (An = U, Np, Pu, and Am; n = 1–3; m = 0, 2, 4; 2n + m = 6) complexes toward Cs are predicted by calculation, and their electronic excitation characteristics were illustrated, providing theoretical supports for the design of Cs adsorbents. The quantum theory of atom in molecules and electron localization function have been implemented to analyze the chemical bonding characterization. The covalent character of An–OC bonds become weaker with increasing COOH– ligands, and the covalent interaction in An–OC bonds is more obvious than that in An–OH bonds. Total and partial population density of state suggest that the 2p orbits of O have more significant contribution in the low-energy region atoms and the 6d/5f orbits of An have more significant contribution in the high-energy region. The Cs+ best adsorption site on [UO2(COOH)2(H2O)2] and [UO2(COOH)3]− is the adjacent oxalates, and the [UO2(COOH)3]− complexes have better adsorption capacity. Besides, the electronic excitation characteristics of Cs+ adsorption on the UO2(COOH)2(H2O)2 complex were analyzed by the UV–vis spectrum and hole–electron distribution.

The Pipeline Problem in Doctoral Counselor Education and Supervision

The hiring of new faculty members in counselor education programs can be complicated by the available pool of qualified graduates with doctoral degrees in counselor education and supervision, as required by the Council for Accreditation of Counseling and Related Educational Programs (CACREP) for core faculty status. A pipeline problem for faculty hiring may exist in regions with fewer doctoral programs. In this study, the researchers examined whether the number of doctoral programs accredited by CACREP is regionally imbalanced. The researchers used an ex post facto study to analyze differences in the number of doctoral programs among the five regions commonly defined by national counselor education associations and organizations. A large and significant difference was found in the number of CACREP-accredited doctoral programs by region, even when population size was statistically controlled. The Western region had by far the fewest number of doctoral programs. The number of CACREP-accredited master’s programs in a state was a large and significant predictor for the number of CACREP-accredited doctoral programs in a state. State population size, state population density, the number of universities per state, and the number of American Psychological Association–accredited counseling psychology programs were not predictors. Demand may surpass supply of doctoral counselor educators in certain regions, resulting in difficulties with hiring new faculty for some CACREP-accredited programs. An analysis of programs currently in the process of applying for CACREP accreditation suggests that this pipeline problem looks likely to continue or even worsen in the near future. Implications for counselor education and supervision are discussed.

Identifying the Relation between Catheter-Associated Urinary Tract Infections and the National Distribution of Urologists and Urology Residencies.

Background: Catheter-associated urinary tract infections (CAUTIs) are associated with urinary catheterization. Up to 25% of hospitalized patients may be catheterized during their stay. Urethral catheters are necessary as part of many urologic procedures, but the removal of unnecessary catheters has become more important to reduce infections, healthcare costs, and patient morbidity. Methods: Open access data from the U.S. Centers for Disease Control and Prevention (CDC), United States Census, and the American Urological Association (AUA) Census was obtained, and a linear correlation used to determine relations. Results: A correlation between the number of urologists per hospital and CAUTIs per hospital was found in both the wards and intensive care units (ICU; p < 0.01). A similar relation was found between the number of urology residencies per hospital and CAUTIs per hospital in the wards (p < 0.01), but this was not significant in the ICU (p = 0.15). The number of urology residencies per state was correlated with the number of urologists per state (p < 0.01). No correlation between state population density and hospital number of CAUTIs, urologists, and urology residencies was found. Conclusions: Increased number of urologic procedures and the need for catheterizations likely drives the correlation with urologists and CAUTIs. Despite this, no urologists are on the CDC committee that created CAUTI guidelines. Urologists should be considered for hospital and national committees particularly because they often care for these patients in the outpatient setting.

CT Volumes from 2,398 Radiology Practices in the United States: A Real-Time Indicator of the Effect of COVID-19 on Routine Care, January to September 2020.

PurposeTo determine the effect of coronavirus disease 2019 (COVID-19) on CT volumes in the United States during and after the first wave of the pandemic.MethodsCT volumes from 2,398 US radiology practices participating in the ACR Dose Index Registry from January 1, 2020, to September 30, 2020, were analyzed. Data were compared to projected CT volumes using 2019 normative data and analyzed with respect to time since government orders, population-normalized positive COVID-19 tests, and attributed deaths. Data were stratified by state population density, unemployment status, and race.ResultsThere were 16,198,830 CT examinations (2,398 practices). Volume nadir occurred an average of 32 days after each state-of-emergency declaration and 12 days after each stay-at-home order. At nadir, the projected volume loss was 38,043 CTs per day (of 71,626 CTs per day; 53% reduction). Over the entire study period, there were 3,689,874 fewer CT examinations performed than predicted (of 18,947,969; 19% reduction). There was less reduction in states with smaller population density (15% [169,378 of 1,142,247; quartile 1] versus 21% [1,894,152 of 9,140,689; quartile 4]) and less reduction in states with a lower insured unemployed proportion (13% [279,331 of 2,071,251; quartile 1] versus 23% [1,753,521 of 7,496,443; quartile 4]). By September 30, CT volume had returned to 84% (59,856 of 71,321) of predicted; recovery of CT volume occurred as positive COVID-19 tests rose and deaths were in decline.ConclusionCOVID-19 substantially reduced US CT volume, reflecting delayed and deferred care, especially in states with greater unemployment. Partial volume recovery occurred despite rising positive COVID-19 tests.

Vibrational, spectroscopic, chemical reactivity, molecular docking and in vitro anticancer activity studies against A549 lung cancer cell lines of 5‐Bromo‐indole‐3‐carboxaldehyde

Spectroscopic investigations are performed for 5-Bromo-1H-indole-carboxaldehyde by using experimental (FT-IR, FT-Raman) and theoretical (DFT) calculations. Vibrational assignments of the fundamental modes were assigned on the basis of Potential energy distribution (PED) calculations. Electron Localization Function (ELF) and Local Orbital Localizer (LOL) studies were performed to visualize the electron delocalization in the molecule. Frontier molecular orbitals (FMOs) and related molecular properties were computed. The electron-hole distribution of the molecule was also computed using Multiwfn 3.3.9 software to predict the charge transfer within the molecule. The total and partial density of states (TDOS and PDOS) and also the overlap population density of states (OPDOS) spectra were simulated. UV-Vis spectrum of the compound was also recorded. The reactive sites of the compound were studied from the MEP and Fukui function analysis. The charge delocalization and stability of the title molecule were investigated using natural bond orbital (NBO) analysis. The lung cancer activity of the title compound against p53 tumor suppressor proteins was studied using molecular docking analysis. The in-vitro cytotoxic activity of the molecule against human pulmonary lung cancer cell lines (A549) was determined by MTT assay.

Efficient tuning of triphenylamine-based donor materials for high-efficiency organic solar cells

Small molecular donors (SMDs) manifest promising photovoltaic performance and rapid progress in solar cells community. Herein, we investigate high-performance triphenylamine (TPA) small molecular donors for solar cells applications. We specifically designed four donor molecules (D1–D4) with a strong donor moiety of triphenylamine (TPA) linked to four different end-capped units. The structure-property relationship and effects of end-capped units on D1-D4 are theoretically calculated and compared with reference molecule R. DFT and TD-DFT approach have been employed and assessments of photophysical characteristics, frontier molecular orbitals (FMOs), reorganization energies, density of state (DOS) and overlap population density of state (OPDOS), open-circuit voltages (Voc), transition density matrix (TDMs), surfaces and charge transfer analysis were conducted. In comparison to synthesized reference molecule R, designed D1-D4 molecules show significant and comparable optoelectronic properties. The D3 designed molecule is proven as the best candidate for solar cells applications than all other due to its promising photovoltaic properties involving the lowest band gap (3.329 eV) and excitation energy (3.094 eV), small reorganization energies for electron (λe = 0.110 eV) and hole (λh = 0.055 eV), low binding energy (Eb = 0.221 eV), highest λmax values 396.69 nm, 400.63 nm both in gas and solvent form, respectively. This theoretical designed model confirms that the end-capped unit modifications proves an efficient alternative solution in achieving the desired optoelectronic properties. Therefore, D1-D4 designed molecules are outstanding and highly recommended to experimentalists for developments of highly efficient solar cells devices in future.

Synthesis, spectra, electronic structure, molecular docking and cytotoxicity investigation on 2-(piperidin-1-ylmethyl)-isoindoline-1,3-dione – A Mannich base system

A Mannich base molecule of 2-(piperidin-1-ylmethyl)isoindoline-1,3-dione (PPF) has been synthesized using Mannich base condensation reaction. The molecular geometry of PPF molecule was optimized by B3LYP/6-311G(d,p) basis set. The vibrational frequencies have been assigned with the aid of normal coordinate analysis. Total energy distributions (TED) were used to explain each vibrational wavenumber assignments of a molecule. The 1H and 13C NMR spectroscopic analyses were predicted by using gauge independent atomic orbital (GIAO) method. The thermal stability was determined by applying the thermo gravimetric/differential scanning calorimetry (TG/DSC) studies. The HOMO-LUMO energies, population density of states (PDOS), overlap population density of states (OPDOS), reduced density gradient (RDG), Mulliken atomic charges and molecular electrostatic potential (MEP) surface were plotted to investigate the van der Waals, attraction, repulsion, non-covalent and covalent interactions of the compound. The natural bond orbital (NBO) charge analysis was used in explaining the intermolecular charge transfer and resonance stabilization energy of molecule. Besides, the molecular docking studies have been performed. The cytotoxic activity of the PPF molecule has been resolved.