Bis(dimethylpyrazolyl)-aniline-s-triazine derivatives as efficient corrosion inhibitors for C-steel and computational studies.

4,6-Bis(3,5-dimethyl-1H-pyrazol-1-yl)-N-phenyl-1,3,5-triazin-2-amine (PTA-1), N-(4-bromophenyl)-4,6-bis(3,5-dimethyl-1H-pyrazol-1-yl)-1,3,5-triazin-2-amine (PTA-2) and 4,6-bis(3,5-dimethyl-1H-pyrazol-1-yl)-N-(4-methoxyphenyl)-1,3,5-triazin-2-amine (PTA-3) were synthesized and characterized. Their corrosion inhibition of carbon C-steel in 0.25 M H2SO4 was studied by electrochemical impedance. The inhibition efficiency (IE%) of triazine was superior due to the cumulative inhibition of triazine core structure and pyrazole motif. Potentiodynamic polarizations suggested that s-triazine derivatives behave as mixed type inhibitors. The IE% values were 96.5% and 93.4% at 120 ppm for inhibitor PTA-2 and PTA-3 bearing -Br and -OCH3 groups on aniline, respectively. While PTA-1 without an electron donating group showed only 79.0% inhibition at 175 ppm. The adsorption of triazine derivatives followed Langmuir and Frumkin models. The values of adsorption equilibrium constant K°ads and free energy change ΔG°ads revealed that adsorption of inhibitor onto steel surface was favoured. A corrosion inhibition mechanism was proposed suggesting the presence of physical and chemical interactions. Density functional theory computational investigation corroborated nicely with the experimental results. Monte Carlo simulation revealed that the energy associated with the metal/adsorbate arrangement dE ads/dN i, for both forms of PTA-2 and PTA-3 with electron donating groups (-439.73 and -436.62 kcal mol-1) is higher than that of PTA-1 molecule (-428.73 kcal mol-1). This aligned with experimental inhibition efficiency results.

Exploring the Sensing Potential of g-C3N4 versus Li/g-C3N4 Nanoflakes toward Hazardous Organic Volatiles: A DFT Simulation Study.

Ab initio calculations were performed to determine the sensing behavior of g-C3N4 and Li metal-doped g-C3N4 (Li/g-C3N4) quantum dots toward toxic compounds acetamide (AA), benzamide (BA), and their thio-analogues, namely, thioacetamide (TAA) and thiobenzamide (TAA). For optimization and interaction energies, the ωB97XD/6-31G(d,p) level of theory was used. Interaction energies (Eint) illustrate the high thermodynamic stabilities of the designed complexes due to the presence of the noncovalent interactions. The presence of electrostatic forces in some complexes is also observed. The observed trend of Eint in g-C3N4 complexes was BA > TAA > AA > TBA, while in Li/g-C3N4, the trend was BA > AA > TBA > TAA. The electronic properties were studied by frontier molecular orbital (FMO) and natural bond orbital analyses. According to FMO, lithium metal doping greatly enhanced the conductivity of the complexes by generating new HOMOs near the Fermi level. A significant amount of charge transfer was also observed in complexes, reflecting the increase in charge conductivity. NCI and QTAIM analyses evidenced the presence of significant noncovalent dispersion and electrostatic forces in Li/g-C3N4 and respective complexes. Charge decomposition analysis gave an idea of the transfer of charge density between quantum dots and analytes. Finally, TD-DFT explained the optical behavior of the reported complexes. The findings of this study suggested that both bare g-C3N4 and Li/g-C3N4 can effectively be used as atmospheric sensors having excellent adsorbing properties toward toxic analytes.

Assessment of particulate matter (PM) in ambient air of different settings and its associated health risk in Haripur city, Pakistan / Avaliação de material particulado (MP) no ar ambiente de diferentes configurações e sua associação com o risco à saúde na cidade de Haripur, Paquistão

Particulate matter (PM) is a major air pollutant causing serious health problems. The aim of the present study was to find out concentration of PM in ambient air and its associated health risk in Haripur city, Pakistan. Twenty-three samples were taken at various educational institutes, hospitals, recreational areas and industries in Haripur city. Concentration of PM2.5 (µg/m3) and PM10 (µg/m3) was measured with Youngteng YT-HPC 3000A portable PM counter. The results revealed that values of both PM2.5 and PM10 were above the permissible limits (35 µg/m3 for PM2.5 and 150 µg/m3 for PM10) set by Environmental Protection Agency Pakistan (Pak-EPA) in all the educational institutes, hospitals, recreational areas and industries investigated. Furthermore, significant (p<0.05) variation was found in the concentration of both PM2.5 and PM10 in all the educational institutes, hospitals, recreational areas, and industries studied. The concentration of PM2.5 was positively correlated with the concentration of PM10 in all the sampling sites. Therefore, from 1-14 scale standard of health index, the values of PM2.5 and PM10 exhibited that the ambient air quality of Haripur city Pakistan is under high risk. If the regulatory authorities such as Environmental Protection Agency, Health Department and Local Government monitor PM pollution in different settings of Haripur city, then a decrease can be possible in the pollution level. The remedies that can be taken to overcome the problem of ambient air pollution such as PM are plantation of trees at the sites where there are higher levels of air pollutants and use of masks on personal protection basis along with implementation of pollution control system in industries of Hattar Industrial Estate Haripur city, Pakistan.

O material particulado (MP) é um importante poluente do ar que causa sérios problemas de saúde. O objetivo do presente estudo foi descobrir a concentração de MP no ar ambiente e sua associação com o risco à saúde na cidade de Haripur, Paquistão. Vinte e três amostras foram coletadas em várias instituições de ensino, hospitais, áreas recreativas e indústrias na cidade de Haripur. A concentração de MP2,5 (µg/m3) e MP10 (µg/m3) foi medida por meio do contador de MP portátil Youngteng YT-HPC 3000A. Os resultados revelaram que os valores de MP2,5 e MP10 estavam acima dos limites permitidos (35 µg/m3 para MP2,5 e 150 µg/m3 para MP10) estabelecidos pela Agência de Proteção Ambiental do Paquistão (Pak-EPA) em todas as instituições de ensino, hospitais, áreas recreativas e indústrias investigadas. Além disso, foi encontrada variação significativa (p < 0,05) na concentração de MP2,5 e MP10 em todos os locais estudados. A concentração de MP2,5 correlacionou-se positivamente com a concentração de MP10 em todos os locais de amostragem. Portanto, a partir da escala padrão 1-14 do índice de saúde, os valores de MP2,5 e MP10 mostraram que a qualidade do ar ambiente na cidade de Haripur, Paquistão, está sob alto risco. Se as autoridades reguladoras, como a Pak-EPA, o Departamento de Saúde e o governo local, monitorarem a poluição por MP em diferentes configurações da cidade de Haripur, pode ser que haja uma diminuição no nível de poluição. As medidas que podem ser tomadas para superar o problema da poluição do ar ambiente, como o MP, são o plantio de árvores nos locais onde há maiores níveis de poluentes atmosféricos, o uso de máscaras e a implantação de sistema de controle de poluição nas propriedades industriais de Hattar, na cidade Haripur, Paquistão.

Assessment of particulate matter (PM) in ambient air of different settings and its associated health risk in Haripur city, Pakistan

Abstract Particulate matter (PM) is a major air pollutant causing serious health problems. The aim of the present study was to find out concentration of PM in ambient air and its associated health risk in Haripur city, Pakistan. Twenty-three samples were taken at various educational institutes, hospitals, recreational areas and industries in Haripur city. Concentration of PM2.5 (µg/m3) and PM10 (µg/m3) was measured with Youngteng YT-HPC 3000A portable PM counter. The results revealed that values of both PM2.5 and PM10 were above the permissible limits (35 µg/m3 for PM2.5 and 150 µg/m3 for PM10) set by Environmental Protection Agency Pakistan (Pak-EPA) in all the educational institutes, hospitals, recreational areas and industries investigated. Furthermore, significant (p 0.05) variation was found in the concentration of both PM2.5 and PM10 in all the educational institutes, hospitals, recreational areas, and industries studied. The concentration of PM2.5 was positively correlated with the concentration of PM10 in all the sampling sites. Therefore, from 1-14 scale standard of health index, the values of PM2.5 and PM10 exhibited that the ambient air quality of Haripur city Pakistan is under high risk. If the regulatory authorities such as Environmental Protection Agency, Health Department and Local Government monitor PM pollution in different settings of Haripur city, then a decrease can be possible in the pollution level. The remedies that can be taken to overcome the problem of ambient air pollution such as PM are plantation of trees at the sites where there are higher levels of air pollutants and use of masks on personal protection basis along with implementation of pollution control system in industries of Hattar Industrial Estate Haripur city, Pakistan.

Resumo O material particulado (MP) é um importante poluente do ar que causa sérios problemas de saúde. O objetivo do presente estudo foi descobrir a concentração de MP no ar ambiente e sua associação com o risco à saúde na cidade de Haripur, Paquistão. Vinte e três amostras foram coletadas em várias instituições de ensino, hospitais, áreas recreativas e indústrias na cidade de Haripur. A concentração de MP2,5 (µg/m3) e MP10 (µg/m3) foi medida por meio do contador de MP portátil Youngteng YT-HPC 3000A. Os resultados revelaram que os valores de MP2,5 e MP10 estavam acima dos limites permitidos (35 µg/m3 para MP2,5 e 150 µg/m3 para MP10) estabelecidos pela Agência de Proteção Ambiental do Paquistão (Pak-EPA) em todas as instituições de ensino, hospitais, áreas recreativas e indústrias investigadas. Além disso, foi encontrada variação significativa (p 0,05) na concentração de MP2,5 e MP10 em todos os locais estudados. A concentração de MP2,5 correlacionou-se positivamente com a concentração de MP10 em todos os locais de amostragem. Portanto, a partir da escala padrão 1-14 do índice de saúde, os valores de MP2,5 e MP10 mostraram que a qualidade do ar ambiente na cidade de Haripur, Paquistão, está sob alto risco. Se as autoridades reguladoras, como a Pak-EPA, o Departamento de Saúde e o governo local, monitorarem a poluição por MP em diferentes configurações da cidade de Haripur, pode ser que haja uma diminuição no nível de poluição. As medidas que podem ser tomadas para superar o problema da poluição do ar ambiente, como o MP, são o plantio de árvores nos locais onde há maiores níveis de poluentes atmosféricos, o uso de máscaras e a implantação de sistema de controle de poluição nas propriedades industriais de Hattar, na cidade Haripur, Paquistão.

Theoretical Study of Dodecafluorophenylene-Based Superalkalides with Significantly High NLO Response.

Scientists are continuously trying to discover new approaches to develop materials with exceptional nonlinear optical responses. Compared with the single-ring Janus face compound (F6C6H6), the three-ring Janus face compound (C13H10F12) has a larger surface, where superalkali metals can be doped quite easily. Herein, the nonlinear optical response of Janus molecule dodecafluorophenylene (DDFP)-based superalkalides has been explored. The stability of the newly designed complexes is evident in the negative interaction energy values (ranging from -42.17 to -60.91 kcal/mol). The superalkalide nature of the complexes is corroborated through natural bond orbital (NBO) analysis, which shows negative charges on M3. This feature is further confirmed through frontier molecular orbital (FMO) analyses showing the highest occupied molecular orbital (HOMO) density over superalkalis (M3). The analysis also reveals that the H-L gap is reduced from 9.57 eV (for bare DDFP) to 2.11 eV for doped systems by adsorption of dopants on the DDFP surface. Moreover, the NLO response of the studied complexes is evaluated via static hyperpolarizabilities. The maximum value of first hyperpolarizability (ßo) among all of the designed compounds is for K3-DDFP-K3 (7.80 × 104 au) at M06-2X/6-31+G(d,p) level of theory. The ßo is also rationalized through a two-level model. Furthermore, for ßvec, the projection of hyperpolarizability on the dipole moment is calculated. The comparable results of ßvec and ßo indicate that the charge transfer in the complexes is parallel to the molecular dipole moments. These compounds, besides providing a new entry into excess-electron compounds, will also pave the way for the design and synthesis of further novel NLO materials.

Decorating Mg12O12 Nanocage with Late First-Row Transition Metals To Act as Single-Atom Catalysts for the Hydrogen Evolution Reaction.

In the pursuit of sustainable clean energy sources, the hydrogen evolution reaction (HER) has attained significant interest from the scientific community. Single-atom catalysts (SACs) are among the most promising candidates for future electrocatalysis because they possess high thermal stability, effective electrical conductivity, and excellent percentage atom utilization. In the present study, the applicability of late first-row transition metals (Fe-Zn) decorated on the magnesium oxide nanocage (TM@Mg12O12) as SACs for the HER has been studied, via density functional theory. The late first-row transition metals have been chosen as they have high abundance and are relatively low-cost. Among the studied systems, results show that the Fe@Mg12O12 SAC is the best candidate for catalyzing the HER reaction as it exhibits the lowest activation barrier for HER. Moreover, Fe@Mg12O12 shows high stability (Eint = -1.64 eV), which is essential in designing SACs to prevent aggregation of the metal. Furthermore, the results of the electronic properties' analysis showed that the HOMO-LUMO gap of the nanocage is decreased significantly upon doping of Fe (from 4.81 to 2.28 eV), indicating an increase in the conductivity of the system. This study highlights the potential application of the TM@nanocage SAC systems as effective HER catalysts.

A computational investigation towards substitution effects on 8π electrocyclisation of conjugated 1,3,5,7-octatetraenes.

A computational investigation using M06-2X/6-31+G(d) method is reported for the substitution effects on 8π electrocyclisation of conjugated octatetraene. This systematic study describes the mono- and di-substitution effect across the 1,3,5,7-octatetraene skeleton. A general preference of the outward substitution over the inward, at C1 position of the monosubstituted system is observed. However, mesomerically electron donating group (-NH2 and -OH) display an opposite effect with respect to secondary orbital interaction (SOI) between the lone pair on the substituent and the orbital. A comparative evaluation on the computed activation energies for the 1-, 2-, 3-, and 4-monosubstituted system showed an insignificant impact on the rate of the reaction, in contrast to the electrocyclic ring closure of the unsubstituted compound. Computations of disubstituted system are more pronounced, where a remarkable acceleration is observed for 2-NO2-7-NO2 substituted octatetraene at 4.9 kcal mol-1, and a noticeable deceleration for 4-CH3-5-CH3 substituted octatetraene at 25.4 kcal mol-1 from the parent molecule, 17.0 kcal mol-1. A visible accelerated effects are commonly exhibited by the substitution on the terminal double bonds (C1, C2, C7, and C8), that are 1,2-, 1,7-, 1,8-, and 2,7-patterns, in regard to the greater orbital interaction for the new σ-bond formation. Despite the unfavourable steric clashes of the substituents in the 1,8-system, an apparent reduction in the energy barrier up to 7.4 kcal mol-1 is computed for 1-NH2-8-NO2 system from 17.0 kcal mol-1. This is due to the synergistic effect of the electron donor and electron acceptor, enhancing the stability of the transition structure. The electrocyclic ring closure involving vicinal substitution patterns, such as 1,2-, 2,3-, 3,4-, and 4,5-systems are critically dominated by steric crowding between the adjacent functional groups. In certain cases of the 1,2-substituted system, a noticeable accelerated effects are found for 1-NH2-2-NH2-substituted compound (9.7 kcal mol-1) due to an increased in electronic density on the substituted terminal double bond (C1-C2), hence favouring the formation of the new σ-bond.

Analyzing COVID-19 Vaccination Side Effects Among the Adult Population in Jeddah, Saudi Arabia.

The COVID-19 pandemic has brought vaccination to the forefront of global attention. The Pfizer-BioNTech vaccine, an mRNA vaccine that encodes the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) glycoprotein spike, has emerged as a significant player in global vaccination efforts. It is generated from lipid nanoparticles and has been subject to various regulatory approvals and authorizations. The United Kingdom became the first country to approve the Pfizer vaccine on December 2, 2020. The World Health Organization (WHO) authorized the emergency use of the Pfizer vaccine on December 31, 2020, facilitating its production and distribution worldwide. In Saudi Arabia, as well as globally, concerns about the safety and effectiveness of vaccines have been raised. Several studies have reported side effects of the Pfizer vaccine, including rare conditions such as myocarditis. In our study, we aimed to systematically investigate the symptoms experienced after vaccination, considering the administration of three doses. We also explored the duration of these symptoms and whether they necessitated hospital visits, primary healthcare interventions, or resolved on their own. Our study employed an online cross-sectional design conducted in Jeddah, Saudi Arabia, utilizing an online self-reported survey. A total of 332 participants who met the predefined criteria were recruited for the study. The rate of COVID-19 infection after 1st and 2nd doses of Pfizer and AstraZeneca vaccines was significantly lower in middle-age subgroups (31-45 years), in comparison to young (18-30 years) and upper middle-age subgroups (46-60 years). For the AstraZeneca vaccine, the infection rate in the middle-aged group was higher after 2nd dose as compared to its 1st dose. Overall, greater infection rates were observed in upper-middle-aged subgroups with all doses of Pfizer and AstraZeneca vaccines. Fatigue and fever were the most common generalized side effects while redness/swelling/pain at the injection site, muscle pain, and joint pain were the most important local side-effects. Fatigue, fever, muscle pain, and joint pain were significantly common after 1st dose of Pfizer and fever was a significant side effect after 2nd dose of Pfizer in comparison to AstraZeneca doses. Understanding the spectrum of side effects associated with the vaccine is crucial for healthcare professionals and individuals receiving the vaccine, as it enables informed decision-making and appropriate management of potential adverse reactions.

Metallofullerenes as Robust Single-Atom Catalysts for Adsorption and Dissociation of Hydrogen Molecules: A Density Functional Study.

Hydrogen is currently considered as the best alternative for traditional fuels due to its sustainable and ecofriendly nature. Additionally, hydrogen dissociation is a critical step in almost all hydrogenation reactions, which is crucial in industrial chemical production. A cost-effective and efficient catalyst with favorable activity for this step is highly desirable. Herein, transition-metal-doped fullerene (TM@C60) complexes are designed and investigated as single-atom catalysts for the hydrogen splitting process. Interaction energy analysis (Eint) is also carried out to demonstrate the stability of designed TM@C60 metallofullerenes, which reveals that all the designed complexes have higher thermodynamic stability. Furthermore, among all the studied metallofullerenes, the best catalytic efficiency for hydrogen dissociation is seen for the Sc@C60 catalyst Ea = 0.13 eV followed by the V@C60 catalyst Ea = 0.19 eV. The hydrogen activation and dissociation processes over TM@C60 metallofullerenes is further elaborated by analyzing charge transfer via the natural bond orbital and electron density difference analyses. Additionally, quantum theory of atoms in molecule analysis is carried out to investigate the nature of interatomic interactions between hydrogen molecules and TMs@C60 metallofullerenes. Overall, results of the current study declare that the Sc@C60 catalyst can act as a low cost, highly efficient, and noble metal-free single-atom catalyst to efficiently catalyze hydrogen dissociation reaction.

Role of Delocalization, Asymmetric Distribution of π-Electrons and Elongated Conjugation System for Enhancement of NLO Response of Open Form of Spiropyran-Based Thermochromes.

Switchable nonlinear optical (NLO) materials have widespread applications in electronics and optoelectronics. Thermo-switches generate many times higher NLO responses as compared to photo-switches. Herein, we have investigated the geometric, electronic, and nonlinear optical properties of spiropyranes thermochromes via DFT methods. The stabilities of close and open isomers of selected spiropyranes are investigated through relative energies. Electronic properties are studied through frontier molecular orbitals (FMOs) analysis. The lower HOMO-LUMO energy gap and lower excitation energy are observed for open isomers of spiropyranes, which imparts the large first hyperpolarizability value. The delocalization of π-electrons, asymmetric distribution and elongated conjugation system are dominant factors for high hyperpolarizability values of open isomers. For deep understanding, we also analyzed the frequency-dependent hyperpolarizability and refractive index of considered thermochromes. The NLO response increased significantly with increasing frequency. Among all those compounds, the highest refractive index value is observed for the open isomer of the spiropyran 1 (1.99 × 10-17 cm2/W). Molecular absorption analysis confirmed the electronic excitation in the open isomers compared to closed isomers. The results show that reversible thermochromic compounds act as excellent NLO molecular switches and can be used to design advanced electronics.

Major Histocompatibility Class-I (MHC-I) downregulation in glioblastoma is a poor prognostic factor but not a predictive indicator for treatment failure.

BACKGROUND: MHC-I expression is a crucial factor in cancer immunity, and its regulations can impact tumor progression and recurrence. The mechanism through which glioblastoma use MHC-I to avoid immunosurveillance has been rarely investigated. METHODS: A retrospective cohort of 35 patients with IDH-mutant WHO-Grade 4 astrocytoma and IDH-wildtype glioblastoma were examined for MHC-I using protein and gene expression assays. The association between IDH mutation, TP53 mutation, and MHC-I expression with recurrence-free interval were investigated. RESULTS: The average patients' age was 49.6 year. IDH was wildtype in 13 tumors. MHC-I protein expression was absent in 30 tumors, faint in 4 tumors, and membrane bound dense expression in single tumor. MHC-I expression was upregulated in 10 tumors and 25 tumors showed MHC-I downregulation. P53 was positively expressed in 19 cases and lost in 13 cases. A significant statistical difference was observed in the RFI between tumors with distinct MHC-I expression and IDH-mutation [p-value = 0.008]. IDH-wildtype tumors with upregulated MHC-I expression showed late tumor recurrence compared to IDH-wildtype tumors with downregulated MHC-I expression. There was insignificant statistical difference in RFI among patients with varying degree of MHC-I expression, who received TMZ or TMZ and other chemotherapies [P-value = 0.44] CONCLUSIONS: Glioblastoma with upregulated MHC-I showed a delayed tumor recurrence in comparison to those with downregulated MHC-I expression. However, downregulated MHC-I may not necessarily be an indicator of poor problems.

Enhanced nonlinear optical response of alkalides based on stacked Janus all-cis-1,2,3,4,5,6-hexafluorocyclohexane.

Significant efforts are continuously exerted by the scientific community to explore new strategies to design materials with high nonlinear optical responses. An effective approach is to design alkalides based on Janus molecules. Herein, we present a new approach to remarkably boost the NLO response of alkalides by stacking the Janus molecules. Alkalides based on stacked Janus molecule, M-n-M' (where n = 2 & 3 while M and M' are Li/Na/K) are studied for structural, energetic, electrical, and nonlinear optical properties. The thermodynamic stability of the designed complexes is confirmed by the energetic stabilities, which range between -14.07 and -28.77 kcal/mol. The alkalide character of alkali metals-doped complexes is confirmed by the NBO charge transfer and HOMO(s) densities. The HOMO densities are located on the doped alkali metal atoms, indicating their alkalide character. The absorptions in UV-Vis and near IR region confirm the deep ultraviolet transparency of the designed complexes. The maximum first static and dynamic hyperpolarizabilities of 5.13 × 107 and 6.6 × 106 au (at 1339 nm) confirm their high NLO response, especially for K-2-M' complexes. The NLO response of alkalides based on stacked Janus molecules is 1-2 orders of magnitude higher than the alkalide based on Janus monomer. The high values of dc-Kerr and electric field-induced response e.g., max ∼107 and 108 au, respectively have been obtained. These findings suggest that our designed complexes envision a new insight into the rational design of stable high NLO performance materials.

Giant NLO response and deep ultraviolet transparency of dual (alkali/alkaline earth) metals doped C6O6Li6 electrides.

The designing of new materials having outstanding nonlinear optical (NLO) response is much needed for use in latest optics. Herein, the geometric, electronic and NLO properties of alkali and alkaline earth metals doped C6O6Li6 (alk-C6O6Li6-alkearth, alkearth = Ca, Mg, Be and alk = K, Na, Li) electrides is studied via quantum chemical approach. The interaction energies (Eint) are examined to illustrate their thermodynamic stability. The strong interaction energy of -39.99 kcal mol-1 is observed for Ca-C6O6Li6-Li electride in comparison to others. Frontier molecular orbitals (FMOs) energy gap of considered complexes is changed due to the electronic density shifting between metals and C6O6Li6 surface, which notifies the semi conducting properties of these electrides. The FMOs isodensities and natural bond orbital (NBO) charge analysis are performed to justify charge transfer between dopants and complexant. UV-Visible study also confirmed the application of these electrides as deep ultra-violet laser devices. NLO response is studied through calculation of first hyperpolarizability (ßo). The highest ßo value of 1.68 × 105 au is calculated for Mg-C6O6Li6-K electride. NLO response is further rationalized by three- and two-level models approach.

Alzheimer's Behavioral and Psychiatric Burden in Saudi Arabia: Validation of the Saudi Version of the Neuropsychiatric Inventory.

BACKGROUND: The burden of behavioral and psychiatric symptoms in dementia (BPSD) has not been characterized in Saudi patients with Alzheimer disease (AD). Moreover, the Saudi version of the Neuropsychiatric Inventory (SNPI) has not been validated. OBJECTIVES: The purpose of this study was to validate the SNPI and describe frequency and determinants of BPSD in Saudi AD patients. METHODS: The SNPI and BEHAVE-AD instruments were administered to community-dwelling Saudi AD patients and their caregivers. RESULTS: The sample size was 192. The first 59 constituted the validation cohort. Cronbach alpha of the SNPI and BEHAVE-AD were 0.91 and 0.79, respectively. There were significant correlations between: (1) the total SNPI and BEHAVE-AD scores ( r =0.84, P <0.001); (2) analogous SNPI and BEHAVE-AD symptom subscores ( P <0.05); (3) SNPI and BEHAVE-AD caregiver distress ( F =22.6, P <0.001). Inter-rater reliability of the SNPI was excellent (kappa=0.74). Ninety percent of patients experienced 4 SNPI symptoms or more. Patients with stroke and prior psychiatric history were most likely to experience BPSDs. The most common symptom was apathy (82%). Caregiver distress was determined by the total NPI score and impulsiveness subscale score. CONCLUSIONS: The SNPI is valid and reliable for assessing BPSD in Saudi AD patients. Longitudinal studies of BPSDs in Saudi specialized dementia clinics are needed.

A three orders of magnitude increase in nonlinear optical response by external electric field on Cryptand[2.2.2] (C222) based alkaline earthides.

A new series of alkaline earthides based on Cryptand [2.2.2] (C222) containing nine complexes is designed by carefully placing alkali metals and alkaline earth metals inside and outside the C222 complexant, respectively i.e., M1(C222)M2 (M1 = Li, Na, K; M2 = Be, Mg, Ca). The designed complexes are reasonably stable both electronically and thermodynamically, as revealed through their vertical ionization potentials (VIPs) and interaction energies, respectively. Moreover, the true alkaline earthide nature of the complexes is confirmed through NBO and FMO analyses showing the negative charges and HOMOs over the alkaline earth metals, respectively. The further validity of true earthide characteristic is represented graphically by the spectra of partial density of states (PDOS). HOMO-LUMO gaps of the compounds are also very small (from 2.23 to 2.83 eV) when compared with pure cage's (C222) H-L gap i.e., 5.63 eV. All these features award these complexes with very small values of transition energies (ΔE) ranging from 0.68 to 2.06 eV ultimately resulting in remarkably high hyperpolarizability values up to 2.7 × 105 au (for Na+(C222)Mg-). Furthermore, applying external electric field (EEF) on the complexes enhances hyperpolarizability further. A remarkable increase of 1000 folds has been seen when hyperpolarizability of K+(C222)Ca- is calculated after EEF application i.e., from 8.79 × 104 au to 2.48 × 107 au; when subjected to 0.001 au external electric field.

Generalized complex cilia tip modeled flow through an electroosmotic region.

In this analysis, we explore a nanofluid model that represents the role of ciliary carpets in the transport of magnetohydrodynamic fluid in an electroosmotic channel. Hybrid nanofluid features are also taken into interpretation. The equations leading the flow analysis are converted into non-dimensional form by supposing long wavelength and low Reynolds number approximations. Analytical solutions for velocity distribution, pressure gradient and stream function are acquired and solved by a mathematic solver. The effects of the relevant physical parameters are graphically noted. The consequence of the present model has remarkable applications, which can be used in various areas of biological transport processes, artificial cilia design and in the operation of other mechanical devices.

Nonlinear Optical Properties and Phototunable Absorption of a Substituted Dihydroazulene-Vinylheptafulvene Pair of Photochromes.

Quantum calculations were used to study UV-vis absorption properties and nonlinear optical characteristics of a variety of substituted dihydroazulene (DHA)/vinylheptafulvene (VHF) photoswitches. The absorption properties are substantially based on the position and nature of the substituent. In general, electron-donating groups cause red shifts compared to the parent compound. Any electron-withdrawing group, on the other hand, would generate a blue shift. Furthermore, the steric effect at some positions is accountable for the loss of planarity and, as a response, a decrease in electronic conjugation within the molecule, which in most cases result in blue shifts in maximum absorption. The purpose of this research is to investigate the influence of substitution at the seven-membered ring of the DHA/VHF system on the absorption spectra and nonlinear optical characteristics of dihydroazulene photoswitches. UV-vis spectra and hyperpolarizability are determined since a prospective photoswitch should have a minimum overlap of absorption spectra from both isomers. Furthermore, the differential in hyperpolarizability between DHA and VHF is critical for practical applications.

Rational Design, Stabilities and Nonlinear Optical Properties of Non-Conventional Transition Metalides; New Entry into Nonlinear Optical Materials.

Electronic and nonlinear optical properties of endohedral metallofullerenes are presented. The endohedral metallofullerenes contain transition metal encapsulated in inorganic fullerenes X12Y12 (X = B, Al & Y = N, P). The endohedral metallofullerenes (endo-TM@X12Y12) possess quite interesting geometric and electronic properties, which are the function of the nature of the atom and the size of fullerene. NBO charge and frontier molecular orbital analyses reveal that the transition metal encapsulated Al12N12 fullerenes (endo-TM@Al12N12) are true metalides when the transition metals are Ni, Cu and Zn. Endo-Cr@Al12N12 and endo-Co@Al12N12 are at the borderline between metalides and electrides with predominantly electride characteristics. The other members of the series are excess electron systems, which offer interesting electronic and nonlinear optical properties. The diversity of nature possessed by endo-TM@Al12N12 is not prevalent for other fullerenes. Endo-TM@Al12P12 are true metalides when the transition metals are (Cr-Zn). HOMO-LUMO gaps (EH-L) are reduced significantly for these endohedral metallofullerenes, with a maximum percent decrease in EH-L of up to 70%. Many complexes show odd-even oscillating behavior for EH-L and dipole moments. Odd electron species contain large dipole moments and small EH-L, whereas even electron systems have the opposite behavior. Despite the decrease in EH-L, these systems show high kinetic and thermodynamic stabilities. The encapsulation of transition metals is a highly exergonic process. These endo-TM@X12Y12 possess remarkable nonlinear optical response in which the first hyperpolarizability reaches up to 2.79 × 105 au for endo-V@Al12N12. This study helps in the comparative analysis of the potential nonlinear optical responses of electrides, metalides and other excess electron systems. In general, the potential nonlinear optical response of electrides is higher than metalides but lower than those of simple excess electron compounds. The higher non-linear optical response and interesting electronic characteristics of endo-TM@Al12N12 complexes may be promising contenders for potential NLO applications.

Chiral Recognition of Amino Acids Using CC2 Porous Organic Cages.

Enantiomers have the same physical properties but different chemical properties due to the difference in the orientation of groups in space and thus Chiral discrimination is quite necessary, as an enantiomer of drug can have lethal effects. In this study, we used the CC2 cage for chiral discrimination of amino acids using density functional theory. The results indicated the physisorption of amino acids in the central cavity of the cage. Among the four selected amino acids, proline showed maximum interactions with the cage and maximum chiral discrimination energy is also observed in the case of proline that is 2.78 kcal/mol. Quantum theory of atoms in molecules and noncovalent interaction index analyses showed that the S enantiomer in each case has maximum interactions. The charge transfer between the analyte and surface is further studied through natural bond orbital analysis. It showed sensitivity of cage for both enantiomers, but a more pronounced effect is seen for S enantiomers. In frontier molecular orbital analysis, the least EH-L gap is observed in the case of R proline with a maximum charge transfer of -0.24 e-. Electron density difference analysis is carried out to analyze the pattern of the charge distribution. The partial density of state analysis is computed to understand the contribution of each enantiomer in overall density of the complexes. Our results show that S-CC2 porous organic cages have a good ability to differentiate between two enantiomers. S-CC2 porous organic cages efficiently differentiated the S enantiomer from the R enantiomers of selected amino acids.

Transition Metal Sensing with Nitrogenated Holey Graphene: A First-Principles Investigation.

The toxicity of transition metals, including copper(II), manganese(II), iron(II), zinc(II), hexavalent chromium, and cobalt(II), at elevated concentrations presents a significant threat to living organisms. Thus, the development of efficient sensors capable of detecting these metals is of utmost importance. This study explores the utilization of two-dimensional nitrogenated holey graphene (C2N) nanosheet as a sensor for toxic transition metals. The C2N nanosheet's periodic shape and standard pore size render it well suited for adsorbing transition metals. The interaction energies between transition metals and C2N nanosheets were calculated in both gas and solvent phases and were found to primarily result from physisorption, except for manganese and iron which exhibited chemisorption. To assess the interactions, we employed NCI, SAPT0, and QTAIM analyses, as well as FMO and NBO analysis, to examine the electronic properties of the TM@C2N system. Our results indicated that the adsorption of copper and chromium significantly reduced the HOMO-LUMO energy gap of C2N and significantly increased its electrical conductivity, confirming the high sensitivity of C2N towards copper and chromium. The sensitivity test further confirmed the superior sensitivity and selectivity of C2N towards copper. These findings offer valuable insight into the design and development of sensors for the detection of toxic transition metals.