Better Mobility Is Associated With Higher Incomes and Longer Working Years Among Older Adults.

BACKGROUND: Robust physical mobility is the key to healthy independent aging. Although the association between socioeconomic status and health is well documented, it is unclear whether there is a relationship between mobility and income, because income data are not readily available. QUESTIONS/PURPOSES: (1) Do individuals with better mobility have higher incomes? (2) Does maintaining mobility over time allow individuals to keep working? (3) Is exercise associated with higher mobility over time? METHODS: We obtained longitudinal income and health data from the nationally representative Health and Retirement Study. Three cohorts were used. First, we studied the relationship between household income and mobility (on a 6-point index of walking impairment) in 19,430 adults who were assessed in 2016 (representing 93% of the 20,805-person total cohort). We measured the association of mobility and household income in a multivariate linear regression analysis of age, gender, health conditions, and education. We then identified a second group of 1094 individuals with unrestricted mobility in the year 2000 and compared differences in income and working rates between those who maintained mobility and those who lost mobility after 10 years. Finally, we identified a third group of 7063 individuals who were 60 to 80 years old in 2012, divided the group by how often they engaged in exercise, and observed differences in mobility after 4 years. RESULTS: After adjusting for covariates, a drop of one level of mobility was associated with a USD 3410 reduction in annual household income (95% CI USD 2890 to USD 3920; p < 0.001). After 10 years, individuals who maintained their mobility had incomes that were USD 6500 higher than that of individuals who were not working (95% CI USD 2300 to USD 10,300; p < 0.001) and were more likely to be working (40% versus 34.5%; p < 0.001). Exercising at least once per week was associated with better mobility 4 years later (mobility score 4.46 ± 0.08 versus 3.66 ± 0.08; p < 0.001). CONCLUSION: Better mobility was associated with more than USD 3000 in annual income. Regular exercise and other interventions that improve mobility may have meaningful returns on investment. CLINICAL RELEVANCE: Because greater mobility is strongly associated with higher income, orthopaedic interventions may be undervalued.

Family Clustering of Autoimmune Vitiligo Results Principally from Polygenic Inheritance of Common Risk Alleles.

Vitiligo is an autoimmune disease that results in patches of depigmented skin and hair. Previous genome-wide association studies (GWASs) of vitiligo have identified 50 susceptibility loci. Variants at the associated loci are generally common and have individually small effects on risk. Most vitiligo cases are "simplex," where there is no family history of vitiligo, though occasional family clustering of vitiligo occurs, and some "multiplex" families report numerous close affected relatives. Here, we investigate whether simplex and multiplex vitiligo comprise different disease subtypes with different underlying genetic etiologies. We developed and compared the performance of several different vitiligo polygenic risk scores derived from GWAS data. By using the best-performing risk score, we find increased polygenic burden of risk alleles identified by GWAS in multiplex vitiligo cases relative to simplex cases. We additionally find evidence of polygenic transmission of common, low-effect-size risk alleles within multiplex-vitiligo-affected families. Our findings strongly suggest that family clustering of vitiligo involves a high burden of the same common, low-effect-size variants that are relevant in simplex cases. We furthermore find that a variant within the major histocompatibility complex (MHC) class II region contributes disproportionately more to risk in multiplex vitiligo cases than in simplex cases, supporting a special role for adaptive immune triggering in the etiology of multiplex cases. We suggest that genetic risk scores can be a useful tool in analyzing the genetic architecture of clinical disease subtypes and identifying subjects with unusual etiologies for further investigation.

Avalanche Preparedness and Accident Analysis Among Backcountry Skier, Sidecountry, and Snowmobile Fatalities in the United States: 2009 to 2019.

INTRODUCTION: While avalanche fatalities have remained relatively steady per year, data suggest a possible increase in sidecountry use and snowmobile fatalities. Limited information is known regarding the accident details and preparedness among different groups of backcountry users including snowmobiles, sidecountry, and backcountry skiers, and what specific factors could contribute to their fatalities. METHODS: Avalanche fatality reports covering all US states posted by the Colorado Avalanche Information Center available online for 10 seasons (2009-2010 through 2018-2019 seasons) were analyzed for group size, specific equipment carried, burial depth, burial time, and other details. Only reports in the 3 following categories were included in the analysis: backcountry ski/snowboard, sidecountry ski/snowboard, and snowmobile/snowbike. These aspects were compared among the 3 tourer types using statistical analyses (ANOVA). RESULTS: Two hundred and five fatalities were analyzed (n=32 sidecountry, n=91 skier/snowboard, n=82 snowmobile/snowbike). Using 2 preparedness scores, the ski/snowboard group had the greatest distribution of high scores when evaluated by equipment carried and group size, with significant differences per group (P<0.01). Of the fatalities that were buried, burial time was related to the tourer group (P=0.04), with the ski/snowboard group having the highest proportion of burials <15 min. Burial depth was significantly different among the 3 tourer groups, with snowmobiles buried the deepest on average (P<0.01). CONCLUSIONS: Despite limited data available on fatalities, an analysis of preparedness suggests that backcountry skiers and snowboarders are more prepared for avalanche accidents compared to snowmobiles and sidecountry users when evaluated by equipment carried and group size.

DFT studies on vibrational and electronic spectra, HOMO-LUMO, MEP, HOMA, NBO and molecular docking analysis of benzyl-3-N-(2,4,5-trimethoxyphenylmethylene)hydrazinecarbodithioate.

Benzyl-3-N-(2,4,5-trimethoxyphenylmethylene)hydrazinecarbodithioate (compound 1) is a bidentate and nitrogen-sulfur containing Schiff base, which has been synthesized by the condensation reaction of S-benzylndithiocarbazate and 2,4,5-trimethoxybenzaldehyde. The theoretical calculations of the mentioned compound have been carried out using the more popular density functional theory method, Becke-3-Parameter-Lee-Yang-Parr (B3LYP) in 6-31G+(d,p) basis set. The computational results of the compound were compared with the obtained experimental value. Moreover, the highest occupied molecular orbital, the lowest unoccupied molecular orbital, molecular electrostatic potential, chemical reactivity parameters and natural bond orbital of the optimized structure have been evaluated at the same level of theory. Furthermore, the UV-Vis spectrum of the compound has been carried out for the better understanding of electronic absorption spectra with the help of the time-dependent density functional theory at room temperature. Besides, the molecular docking simulation of the mentioned molecule with target protein was also investigated. In addition, in silico studies were performed to predict absorption, distribution, metabolism, excretion and toxicity profiles of the designed compound. The results indicated that the theoretical data have well correlated with the observed values. The narrow frontier orbital gap indicated that the eventual charge transfer interaction occurs within the studied molecule and showed high chemical reactivity. The global reactivity values showed that the compound is soft molecule, electrophilic species and has strong binding ability with biomolecules. The molecular electrostatic potential structure indicated that the negative and positive potential sites are around electronegative atoms and hydrogen atoms of studied compound, respectively. The natural bond orbital data revealed that the compound contains 97.42% Lewis and 2.58% non-Lewis structure. The intra and inter-molecular charge transfers process occur within the studied compound. The studied compound showed more binding energy (-6.0 kcal/mol) with target protein than hydroxychloroquine (-5.6 kcal/mol). The absorption, distribution, metabolism, excretion and toxicity investigation predicted that the compound has good drug like character.

First Report of Plant-Derived ß-Sitosterol with Antithrombotic, in Vivo Anticoagulant, and Thrombus-Preventing Activities in a Mouse Model.

Inhibitors of thrombin, a key enzyme in the blood coagulation cascade, are of great interest because of their selective specificity and effectiveness in anticoagulation therapy against cardiovascular disorders. The natural soybean phytosterol, ß-sitosterol (BSS) demonstrated anticoagulant activity by dose-dependent inhibition of thrombin in an uncompetitive manner with a Ki value of 0.267 µM as well as by partial inhibition of thrombin-catalyzed platelet aggregation with a half-maximal inhibitory concentration (IC50) value of 10.45 ± 2.88 µM against platelet-rich plasma and 9.2 ± 1.2 µM against washed platelets. An in silico study indicated binding of BSS to thrombin, which was experimentally verified by spectrofluorometric and isothermal calorimetric analyses. Under in vitro conditions, BSS demonstrated thrombolytic activity by activating plasminogen, albeit it is devoid of protease (fibrinogenolytic) activity. BSS was noncytotoxic to mammalian cells, nonhemolytic, demonstrated its in vivo anticoagulant activity when administered orally, and inhibited k-carrageen-induced thrombus formation in the tails of mice. Our results suggest that dietary supplementation of BSS may help to prevent thrombosis-associated cardiovascular disorders.

Sustainability assessment for the transportation environment of Darjeeling, India.

Darjeeling is an important tourist hill town of West Bengal, India. It suffers from an acute problem of transportation, particularly during its peak tourist seasons due to limited road space, inadequate public transport facilities and indiscriminate use of automobiles. This hill town was originally designed for a population of 10,000, but over the years, it has come face-to-face with rapid urbanization, a rising population of both tourists and residents and intensifying motor vehicle usage. These factors together are posing a threat to its transport environment. This study identifies the Sustainable Transport Indicators (STIs) available in the existing literature to identify the critical stretches using Analytical Hierarchy Process (AHP) based on experts' consensus. It was found that the experts placed emphasis on the mobility of the town, talking about vehicular impact on air pollution and encroachment of roads as the main issues affecting the sustainability of the transport environment. Thereafter, policy-level interventions have been suggested in accordance with the identified sustainability issues. We trust that other tourist hill towns with issues similar to Darjeeling could easily emulate the study methodology to assess their transport environment sustainability, or replicate on the lines of the recommended policy interventions.

Synthesis, quantum chemical calculations, in silico and in vitro bioactivity of a sulfonamide-Schiff base derivative.

The sulfonamide Schiff base compound (E)-4-((4-(dimethylamino)benzylidene)amino)-N-(5-methylisoxazol-3-yl)benzenesulfonamide was successfully prepared and fully characterized. The foremost objective of this study was to explore the molecular geometry of the aforementioned compound and determine its drug likeness characteristics, docking ability as an insulysin inhibitor, anticancer and antioxidant activities. The molecular structure of this compound was optimized using the B3LYP/6-311G+(d,p) level of theory. The compound was completely characterized utilizing both experimental and DFT approaches. Molecular electrostatic potential, frontier molecular orbitals, Fukui function, drug likeness, and in silico molecular docking analyses of this compound were performed. Wave functional properties such as localized orbital locator, electron localization function and non-covalent interactions were also simulated. The compound was screened for anticancer and antioxidant activities using in vitro technique. The observed FT-IR, UV-Vis, and 1H NMR results compared with simulated data and both results were fairly consistent. The experimental and computational spectral findings confirm the formation of the Schiff base compound. Both π-π* and n-π* transitions were observed in both experimental and computational UV-Vis spectra. The examined compound followed to Pfizer, Golden Triangle, GSK, and Lipinski's rules. Consequently, it possesses a more favorable absorption, distribution, metabolism, excretion, and toxicity (ADMET) profile, making it a suitable candidate for non-toxic oral drug use. Moreover, the compound exhibited promising insulysin inhibition activity in an in silico molecular docking. The compound showed in vitro anticancer activity against A549 cancer cells with an IC50 value of 40.89 µg/mL and moderate antioxidant activity.

Oxidation pathways and kinetics of the 1,1,2,3-tetrafluoropropene (CF2CF-CH2F) reaction with Cl-atoms and subsequent aerial degradation of its product radicals in the presence of NO.

To give a comprehensive account of the environmental acceptability of 1,1,2,3-tetrafluoropropene (CF2CF-CH2F) in the troposphere, we have examined the oxidation reaction pathways and kinetics of CF2CF-CH2F initiated by Cl-atoms using the second-order Møller-Plesset perturbation (MP2) theory along with the 6-31+G(d,p) basis set. We also performed single-point energy calculations to further refine the energies at the CCSD(T) level along with the basis sets 6-31+G(d,p) and 6-311++G(d,p). The estimation of the relative energies and thermodynamic parameters of the CF2CF-CH2F + Cl reaction clearly shows that Cl-atom addition reaction pathways are more dominant compared to H-abstraction reaction pathways. The value of the rate coefficient for each reaction channel is calculated using the conventional transition state theory (TST) over the temperature range of 200-1000 K at 1 atm. The estimated overall rate coefficients for the title reaction are found to be 1.10 × 10-12, 1.21 × 10-10, and 1.13 × 10-8 cm3 per molecule per s via the respective calculation methods viz. MP2/6-31+G(d,p), CCSD(T)//MP2/6-31+G(d,p), and CCSD(T)/6-311++G(d,p)//MP2/6-31+G(d,p), at 298.15 K. Moreover, the calculated rate coefficients and percentage branching ratio values suggest that the Cl-atom addition reaction at the ß-carbon atom is more preferable to that of the α-carbon addition to CF2CF-CH2F. Based on the rate coefficient values calculated by the three different methods, the atmospheric lifetime for the title reaction at 298.15 K is estimated. The radiative efficiency (RE) and Global Warming Potential (GWP) results of the title molecule show that its GWP would be negligible. Further, we have explored the degradation of its product radicals in the presence of O2 and NO. From the degradation results, we have found that CF2(Cl)COF, FCOCH2F, FCFO and FCOCl are formed as stable end products along with various radicals such as ˙CF2Cl and ˙CH2F. Therefore, these findings of kinetic and mechanistic data can be applied to the development and implementation of a novel CFC replacement.

Intrinsic endothelial hyperresponsiveness to inflammatory mediators drives acute episodes in models of Clarkson disease.

Clarkson disease, or monoclonal gammopathy-associated idiopathic systemic capillary leak syndrome (ISCLS), is a rare, relapsing-remitting disorder featuring the abrupt extravasation of fluids and proteins into peripheral tissues, which in turn leads to hypotensive shock, severe hemoconcentration, and hypoalbuminemia. The specific leakage factor(s) and pathways in ISCLS are unknown, and there is no effective treatment for acute flares. Here, we characterize an autonomous vascular endothelial defect in ISCLS that was recapitulated in patient-derived endothelial cells (ECs) in culture and in a mouse model of disease. ISCLS-derived ECs were functionally hyperresponsive to permeability-inducing factors like VEGF and histamine, in part due to increased endothelial nitric oxide synthase (eNOS) activity. eNOS blockade by administration of N(γ)-nitro-l-arginine methyl ester (l-NAME) ameliorated vascular leakage in an SJL/J mouse model of ISCLS induced by histamine or VEGF challenge. eNOS mislocalization and decreased protein phosphatase 2A (PP2A) expression may contribute to eNOS hyperactivation in ISCLS-derived ECs. Our findings provide mechanistic insights into microvascular barrier dysfunction in ISCLS and highlight a potential therapeutic approach.

The influence of trehalose on hydrophobic interactions of small nonpolar solute: A molecular dynamics simulation study.

Molecular dynamics simulations were carried out to investigate the influences of aqueous trehalose solution on the hydrophobic interactions between neopentane molecules. In this study, we consider six different trehalose concentrations ranging from 0% to 56%. We observe that with increasing trehalose concentration the dispersion of solute neopentane takes place. The neopentane-neopentane association constant value decreases with addition of trehalose. Our preferential interaction calculations suggest that with increasing trehalose concentration neopentane interacts preferentially with water over trehalose. Site-site neopentane-trehalose rdfs indicate that trehalose molecules are expelled out from the neopentane surface. Also observed are (i) trehalose induced second shell collapse of water network (ii) decrease in average number of water-water and water-trehalose hydrogen bonds with increasing trehalose concentration. We also find that addition of trehalose decreases the translational motion of all the solution species. The decrease in diffusion coefficient value is more pronounced for trehalose. We, further, observe that the ratio of the diffusion coefficient values of water and trehalose increases with increasing trehalose concentration.

Bone health is improving over time: data from Framingham cohorts.

Hip fractures have steadily declined in the USA. We found that bone health, as measured by bone mineral density, has significantly improved over the past 30 years. Our findings contradict previous studies and offer one explanation for the decline in hip fractures. PURPOSE: Despite the widespread undertreatment of osteoporosis, hip fractures have been declining in the USA. The reasons for this decline are unclear; however, one possible explanation could be that the bone health has improved over time. METHODS: To determine the trends in bone density in the USA, we analyzed the bone mineral density scans of 7216 subjects across three generations in the Framingham Heart Study. We compared the mean femoral bone mineral density (BMD) between cohorts then constructed a linear regression model controlling for age, sex, BMI, and smoking rates. RESULTS: We observed that the mean BMD of each successive Framingham cohort increased (p < 0.001). After controlling for age, subjects born later had higher BMD. The results from the linear-regression model developed on the original cohort indicated that the BMD of the women from the offspring and third generation were higher than what would be predicted. Younger generations demonstrated higher activity scores (p < 0.001), and lower smoking rates (p = 0.045). CONCLUSION: These data suggest that bone health, measured by bone mineral density scans, is improving in later generations, in part due to decreased smoking rates and higher rates of activity.

Fractional order SEIQRD epidemic model of Covid-19: A case study of Italy.

The fractional order SEIQRD compartmental model of COVID-19 is explored in this manuscript with six different categories in the Caputo approach. A few findings for the new model's existence and uniqueness criterion, as well as non-negativity and boundedness of the solution, have been established. When RCovid19<1 at infection-free equilibrium, we prove that the system is locally asymptotically stable. We also observed that RCovid 19<1, the system is globally asymptotically stable in the absence of disease. The main objective of this study is to investigate the COVID-19 transmission dynamics in Italy, in which the first case of Coronavirus infection 2019 (COVID-19) was identified on January 31st in 2020. We used the fractional order SEIQRD compartmental model in a fractional order framework to account for the uncertainty caused by the lack of information regarding the Coronavirus (COVID-19). The Routh-Hurwitz consistency criteria and La-Salle invariant principle are used to analyze the dynamics of the equilibrium. In addition, the fractional-order Taylor's approach is utilized to approximate the solution to the proposed model. The model's validity is demonstrated by comparing real-world data with simulation outcomes. This study considered the consequences of wearing face masks, and it was discovered that consistent use of face masks can help reduce the propagation of the COVID-19 disease.

Physicochemical reports of gliclazide-carplex solid dispersions and tablets prepared with directly compressible co-processed excipients.

Objectives: The main goal of this research was to develop better tablet formulations by utilizing solid dispersions (SDs) and coprocessing excipients composite to achieve a better release rate of poor water-soluble gliclazide. Methods: The solvent evaporation method made SDs of gliclazide with different carriers carplex 67, carplex 80, and carplex FPS 500 (weight ratio, 1:1). The drug release patterns of the SDs were all evaluated and optimized. The SDs were illustrated by using scanning electron microscopy (SEM), differential scanning calorimetry (DSC), X-ray powder diffraction (PXRD), and Fourier transform infrared spectroscopy (FTIR). Tablet batches FGC-1 to 8 were made using gliclazide-carplex 67 solid dispersions (GC67-SDs) and the co-processed composite of excipients, namely starch-MCC-povidone (SMP) and lactose-MCC-povidone-sodium starch glycolate (LMPS), prepared with coprocessing technology. We evaluated these batches by conducting physicochemical tests and comparing them to the existing commercial brand. Results: In a water medium, the release of gliclazide from SDs peaked within the first 30 min, showing a roughly 5∼6-fold increase compared to plain gliclazide. This quick dissolution rate may be due to the amorphization of the drug, which improved the specific surface area, and increased wettability caused by the hydrophilic properties of carplex particles. This has been confirmed through SEM, DSC, FTIR, and PXRD analysis. All FGC formulations had satisfactory pre-compression factor results, while the post-compression parameters indicated good mechanical strength and homogeneity across the blend. All produced tablets met the weight variation, friability, and disintegration time limit set by the compendia. Through in vitro drug release testing, it was discovered that all FGC tablet batches had consistent and nearly identical release results compared to SDs of gliclazide. However, the FGC-5 to 8 batches containing LMPS composites were determined to be the most effective formulations. In the first 30 min in a water medium, the percentage of drug generated from the FGC-8 tablets involving GC67-SDs and co-processed composite LMPS-4 is approximately 3.5 times higher than the average release of currently marketed products (MPs). After storing the selected FGC tablet batches for three months at 40 °C and 75 % RH, there were no noticeable alterations in the amount of drug and drug release profiles across the batches. Conclusion: Based on these findings, it appears that using the carplex silica-based SDs approach, along with gliclazide and co-processing excipients composite, could result in significant benefits compared to the current commercial brands. This approach could be effectively utilized to create solid dosage forms for drugs that have low solubility in water.

Economic burden of dengue in urban Bangladesh: A societal perspective.

BACKGROUND: Dengue, a vector-borne disease, is a major public health problem in many tropical and subtropical countries including Bangladesh. The objective of this study is to estimate the societal cost of illness of dengue infections among the urban population in Dhaka, Bangladesh. METHODS: A cost-of-illness study was conducted using a prevalence-based approach from a societal perspective. Costs attributable to dengue were estimated from a bottom-up strategy using the guideline proposed by the World Health Organization for estimating the economic burden of infectious diseases. RESULTS: A total of 302 hospitalized confirmed dengue patients were enrolled in this study. The average cost to society for a person with a dengue episode was US$ 479.02. This amount was ranged between US$ 341.67 and US$ 567.12 for those patients who were treated at public and private hospitals, respectively. The households out-of-pocket cost contributed to a larger portion of the total costs of illness (66%) while the cost burden was significantly higher for the poorest households than the richest quintile. CONCLUSIONS: Dengue disease imposes a substantial financial burden on households and society. Therefore, decision-makers should consider the treatment cost of dengue infections, particularly among the poor in the population while balancing the benefits of introducing potentially effective dengue preventive programs in Bangladesh.

Stability analysis and Hopf bifurcation in fractional order SEIRV epidemic model with a time delay in infected individuals.

Infectious diseases have been a constant cause of disaster in human population. Simultaneously, it provides motivation for math and biology professionals to research and analyze the systems that drive such illnesses in order to predict their long-term spread and management. During the spread of such diseases several kinds of delay come into play, owing to changes in their dynamics. Here, we have studied a fractional order dynamical system of susceptible, exposed, infected, recovered and vaccinated population with a single delay incorporated in the infectious population accounting for the time period required by the said population to recover. We have employed Adam-Bashforth-Moulton technique for deriving numerical solutions to the model system. The stability of all equilibrium points has been analyzed with respect to the delay parameter. Utilizing actual data from India COVID-19 instances, the parameters of the fractional order SEIRV model were calculated. Graphical demonstration and numerical simulations have been done with the help of MATLAB (2018a). Threshold values of the time delay parameter have been found beyond which the system exhibits Hopf bifurcation and the solutions are no longer periodic.

Dynamics of SIQR epidemic model with fractional order derivative.

The dynamics of COVID-19 (Coronavirus Disease-2019) transmission are described using a fractional order SIQR model. The stability analysis of the model is performed. To obtain semi-analytic solutions to the model, the Iterative Laplace Transform Method [ILTM] is implemented. Real-time data from COVID-19 cases in India and Brazil is employed to estimate the parameters of the fractional order SIQR model. Numerical solutions obtained using Adam-Bashforth-Moultonpredictor-corrector technique is compared with those obtained by ILTM. It is observed that the fractional order of the derivatives is more effective in studying the dynamics of the spread of COVID-19 in comparison to integral order of the SIQR model.

Dynamics of Caputo Fractional Order SEIRV Epidemic Model with Optimal Control and Stability Analysis.

In mid-March 2020, the World Health Organization declared COVID-19, a worldwide public health emergency. This paper presents a study of an SEIRV epidemic model with optimal control in the context of the Caputo fractional derivative of order 0 < ν ≤ 1 . The stability analysis of the model is performed. We also present an optimum control scheme for an SEIRV model. The real time data for India COVID-19 cases have been used to determine the parameters of the fractional order SEIRV model. The Adam-Bashforth-Moulton predictor-corrector method is implemented to solve the SEIRV model numerically. For analyzing COVID-19 transmission dynamics, the fractional order of the SEIRV model is found to be better than the integral order. Graphical demonstration and numerical simulations are presented using MATLAB (2018a) software.

Study of Fractional Order SEIR Epidemic Model and Effect of Vaccination on the Spread of COVID-19.

In this manuscript, a fractional order SEIR model with vaccination has been proposed. The positivity and boundedness of the solutions have been verified. The stability analysis of the model shows that the system is locally as well as globally asymptotically stable at disease-free equilibrium point E 0 when R 0 < 1 and at epidemic equilibrium E 1 when R 0 > 1 . It has been found that introduction of the vaccination parameter η reduces the reproduction number R 0 . The parameters are identified using real-time data from COVID-19 cases in India. To numerically solve the SEIR model with vaccination, the Adam-Bashforth-Moulton technique is used. We employed MATLAB Software (Version 2018a) for graphical presentations and numerical simulations.. It has been observed that the SEIR model with fractional order derivatives of the dynamical variables is much more effective in studying the effect of vaccination than the integral model.

Effect of aging on immune cells in male HIV-infected and -uninfected healthy individuals.

OBJECTIVE: HIV induces immunologic dysfunction in T cells of infected individuals. However, the impact of aging on T cell phenotypes in HIV-infected individuals receiving antiretroviral therapy (ART) has not been fully delineated. We evaluated the relationship between aging and the expression of immune activation and exhaustion markers on CD8 + T cells of age-matched HIV-infected and -uninfected male participants. DESIGN: Levels of immune activation and exhaustion markers on peripheral blood CD8 + T cells of HIV-infected and -uninfected participants were examined. METHODS: 110 HIV-infected aviremic male participants receiving ART and 146 HIV-uninfected male participants were studied. The levels of TIGIT, PD-1, CD38, and CD226 on CD8 + T cells of the study participants were determined by flow cytometry. RESULTS: The level of TIGIT on CD8 + T cells was higher in aviremic HIV-infected compared to uninfected participants ( P  < 0.0001). In contrast, no significant differences were found in the levels of PD-1 and CD38 on CD8 + T cells between the two groups. Statistically significant correlations were observed between age and the levels of TIGIT + and CD38 + CD8 + T cells in both groups; however, no correlation was found between age and the level of PD-1 + CD8 + T cells in HIV-infected participants. Age-stratification of HIV-infected and -uninfected groups did not show any significant differences in the level of PD-1 expression on CD8 + T cells. CONCLUSIONS: The findings of our study highlight the role of aging in the expression of immune markers on CD8 + T cells and have important implications for therapies that target immune checkpoints in HIV-infected individuals.

Study of SEIR epidemic model and scenario analysis of COVID-19 pandemic.

In recent times, the Coronavirus disease (caused by COVID-19) is evidently observed to be the extremely contagious one with high fatality rate worldwide. In March 2020, the disease was declared a "global pandemic" by the World Health Organization (WHO). So far, there is no known/effective vaccine or medicine. In this paper, we propose and analyze an SEIR compartment model. We also compare and analyze the case study of India and Brazil. The model system is discussed by using MATLAB (2018a) software and the numerical results are verified graphically.