Sixth order compact multi-phase block-AGE iteration methods for computing 2D Helmholtz equation.

We discuss sixth order accurate 9-point compact 2- and 3-phase block alternating group explicit (block-AGE) iteration methods for computing 2D Helmholtz equation. We use Dirichlet boundary conditions and no fictitious points are involved outside the solution region for computation. The proposed 2- and 3-phase block-AGE methods require only two and three sweeps for computation and the error analysis of the suggested approximation is analyzed. We have compared the 2- and 3-phase block-AGE iteration methods with the corresponding block successive over relaxation (block-SOR) method in three experiments, in regard to number of iterations required for convergence and cpu time, where the importance of the role performed by optimal relaxation parameters of the proposed block-AGE iteration methods become evident in stipulating the convergence and precision of the calculated results. In all cases we use the tridiagonal solver and obtain the optimal relaxation parameters through computation.

Spline-in-compression approximation of order of accuracy three (four) for second order non-linear IVPs on a graded mesh.

A spline-in-compression method, implicit in nature, for computing numerical solution of second order nonlinear initial-value problems (IVPs) on a mesh not necessarily equidistant is discussed. The proposed estimation has been derived directly from consistency condition which is third-order accurate. For scientific computation, we use monotonically descending step lengths. The suggested method is applicable to a wider range of physical problems including the problems which are singular in nature. This is possible due to off-step discretization employed in the spline technique. We examine the absolute stability and super-stability of the method when applied to a problem of physical significances. We have shown that the method is absolutely stable in the case of graded mesh and super stable in the case of constant mesh. The advantage of our method lies in it being highly cost and time effective, as we employ a three-point compact stencil, thereby reducing the algebraic calculations considerably. The proposed method which is applicable to singular, boundary layer and singularly perturbed problems is a research gap which we overcame by proposing this new compact spline method.

Higher order approximation in exponential form based on half-step grid-points for 2D quasilinear elliptic BVPs on a variant domain.

This paper reports a new fourth order Finite Difference Method (FDM) in exponential form for two-dimensional quasilinear boundary value problem of elliptic type (BVPE) with variant solution domain. Further, this discretization is extended to solve the system of quasilinear BVPEs. Following are the main highlights of the proposed FDM: • An unequal mesh 9-point compact stencil is used to approximate the solution. Half-step points are used to evaluate the known variables of this problem. The convergence theory is studied for unequal mesh to validate the fourth order convergence of the suggested FDM. • It is applicable to BVPE irrespective of coordinate systems. Various benchmark problems, for example, Poisson equation in cylindrical coordinates, Burgers' equation, Navier-Stokes (NS) equations in cylindrical and rectangular coordinates, are solved to depict their fourth order convergence. • Numerical results confirm the accuracy, trustworthiness and acceptability of the suggested numerical algorithm. These results endorse the superiority of the proposed FDM over the previously existing techniques of Mohanty and Kumar (2014), Mohanty and Setia (2014), Priyadarshini and Mohanty (2021).

Conformity assessment with structural strength requirements of mechanical polycentric prosthetic knee used for amputee rehabilitation.

Prosthetic restoration is an important component of amputee rehabilitation which may be subjected to a static load of nearly five times of amputees' body weight and is continuously administered to cyclic or fatigue loads during its function. This study presents a structural strength analysis of polycentric mechanical prosthetic knee commonly used in National Institutes in India by finite element simulation and its experimental validation. Static and fatigue analyses have been performed to ensure its structural integrity as per the ISO 10328:2006 standard. Accurate dimensioning of knee components have been obtained using coordinate measuring machine and the 3 D CAD model has been generated by CATIA V5 from the 2 D geometry. The model is imported to the ANSYS 20.1 workbench to study stress distribution in the knee for ensuring its safety performance. The selection of reference planes, application of calculated loads, and position of load line have been done as per the ISO test procedure. Static and cyclic loadings of 4130 N and 1230 N are applied at the top and the bottom plate is given with translational constraints to limit its movement in any direction. Results indicate that the prosthetic knee model is moderately strong enough to outstrip the static strength test. However, the calculated strain and predicted fatigue life during the cyclic test suggest that this knee unit has poor fatigue strength. Validation results with an average error percentage of 3.44 and 10 show higher reliability based on previous study results and experimental tests, respectively.

High precision compact numerical approximation in exponential form for the system of 2D quasilinear elliptic BVPs on a discrete irrational region.

This article presents a new approximation of order four in exponential form for two-dimensional (2D) quasilinear partial differential equation (PDE) of elliptic form with solution domain being irrational. It is further extended for application to a system of quasilinear elliptic PDEs with Dirichlet boundary conditions (DBCs). The main highlights of the method framed in this article are as under:•It uses a 9-point stencil with unequal mesh to approach the solution. The error analysis is discussed to authenticate the order of convergence of the proposed numerical approximation.•Various validating problems, for instance the Burgers' equation, Poisson equation in cylindrical coordinates, Navier-Stokes (NS) equations in rectangular and cylindrical coordinates are solved using the proposed techniques to depict their stability. The proposed approximation produces solution free of oscillations for large values of Reynolds Number in the vicinity of a singularity.•The results of the proposed method are superior in comparison to the existing methods of [49] and [56].

Clinical effectiveness of Lactobacillus reuteri in the treatment of peri-implant diseases: a systematic review and meta-analysis.

In the last decades, the presence of peri-implant diseases (PD) has increased. One of the therapies currently used is probiotics with Lactobacillus reuteri (LR). The aim of this article is to determinate, through a systematic review and meta-analysis, the clinical effectiveness of LR in the treatment of PD. We searched the literature until January 2021, in the biomedical databases: Pubmed, Embase, Scielo, Science Direct, Scopus, SIGLE, LILACS, Google Scholar and Cochrane Central Registry of Clinical Trials. The selection criteria of the studies were: randomized controlled clinical trials, without language and time restriction, reporting the clinical effects (depth to probing, plaque index and bleeding index) of the LR in the PD treatment. The risk of study bias was analyzed through the Cochrane tool for randomized studies using Review Manager software. The search strategy resulted in 6 articles of which four investigated peri-implantitis and three peri-implant mucositis. All studies reported that there was a difference in the depth of the probing in the treatment of PD, in favor of the group using LR, though not always achieving significance. The use of LR can be clinically effective in terms of pocket depth reduction in the treatment of PD.

Clinical efficacy of grape seed extract as an adjuvant to scaling and root planing in treatment of periodontal pockets.

Grape seed extract (GSE), a naturally producing polyphenolic compound, is found to be a potent hostmodulatory agent and considered for management of periodontal disease. Its anti-bacterial, antioxidant, and anti-inflammatory property may aid in achieving periodontal health. To assess the clinical efficacy of GSE in adjunct to scaling and root planing (SRP) in healing of periodontal pockets. The present study was a longitudinal, parallel design, randomized clinical trial. Seventy-two patients (mean age 39.2±8.6 years) with periodontal pockets were randomly divided into two groups; Test group received intra-pocket delivery of GSE with SRP and Control group received SRP alone. The clinical parameters like Plaque Index (PI), Gingival Index (GI), Probing Depth (PD) and Relative Attachment Level (RAL) were recorded at baseline and 3 months. 64 patients completed the study. Test group at the end of 3 months had statistically significant reduced PD (p=0.002) and RAL (p=0.01). No significant difference was observed for PI and GI at the end of 3 months. Intra-pocket application of GSE with SRP could be beneficial in management of periodontal pockets.

Therapeutic potential of N-acetyl cysteine (NAC) in preventing cytokine storm in COVID-19: review of current evidence.

Since November 2019, SARS Coronavirus 2 disease (COVID-19) pandemic has spread through more than 195 nations worldwide. Though the coronavirus infection affects all age and sex groups, the mortality is skewed towards the elderly population and the cause of death is mostly acute respiratory distress syndrome (ARDS). There are data suggesting the role of excessive immune activation and cytokine storm as the cause of lung injury in COVID-19. The excessive immune activation and cytokine storm usually occurs due to an imbalance in redox homeostasis of the individuals. Considering the antioxidant and free radical scavenging action of N acetyl cysteine (NAC), its use might be useful in COVID-19 patients by decreasing the cytokine storm consequently decreasing the disease severity. Therefore, we reviewed all the available resources pertaining to the role of reactive oxygen species (ROS) in cytokine storm and the mechanism of action of NAC in preventing ROS. We also reviewed the use of NAC in COVID-19.

Effect of internet use on medical students before and after 4g internet service in india: A comparative study.

BACKGROUND: Internet is being used extensively throughout the world from last decade. In India internet service has entered into new generation called 4G. Medical students are particularly vulnerable group for problematic internet use on account of the time they spend online. This might have negative effects on their physical, psychological and social health. Hence they are more prone to internet addiction. AIMS: To compare use and effect of internet service among medical students before and after the availability of 4G service. STUDY DESIGN: Institution based cross sectional study. METHODS AND MATERIAL: Predesigned validated questionnaires were provided to the medical students in the year 2014. The questionnaire included demographics, pattern of internet use and Young's internet addiction test. Again in the year 2018 the similar procedure was carried out after introduction of 4G service. The data was collected and compared. Analysis was done using SPSS 25. STATISTICAL ANALYSIS: Descriptive statistics, Chi2 test and Mann-Whitney test was applied. RESULTS: Among 424 medical students 207 students were assessed in the year 2014 and 217 students in 2018.There was a significant change of pattern of use. Also significant increase in number of female users and severity of internet addiction in 2018. The ill effect of internet was on rise after availability of 4G service. CONCLUSIONS: The prevalence of internet addiction and its ill effect on behavior among medical students was higher after availability of 4G service in same college. So appropriate preventive and interventional strategies need to be developed in professional institutions.

A systematic review on design technology and application of polycentric prosthetic knee in amputee rehabilitation.

The objective of this paper is to conduct a systematic review on design technology and clinical application of polycentric prosthetic knee joint in the rehabilitation of trans-femoral amputees. Relevant studies were identified using electronic database such as PubMed, EMBASE, SCOPUS and the Cochrane Controlled Trials Register (Rehabilitation and Related Therapies) up to February 2020. Screening of abstracts and application of inclusion and exclusion criteria were made. Design, modeling, material use, kinematic study, simulation technique and clinical application of polycentric knee models used in many developed and developing countries have been reviewed. Out of 516 potentially relevant studies, 43 articles were included. Specific variables on technical and clinical aspects were extracted and added to summary tables. The results reveal that polycentric knees have a variety of geometries but the methods for comparing their performances are rare. The data of structural analysis using different simulation techniques are validated with experimental results for determining model accuracy. Gait analysis using the polycentric knee components provides a valid tool to correlate with experimental results. There are well-designed studies on the technological development of polycentric knees, however, high-quality clinical researches are scarce. Conventional clinical knowledge had considerable gaps concerning the effects of polycentric knee and their mechanical characteristics on human functioning with a lower-limb prosthesis. Still, further research is needed to develop and implement standardized measures on prosthetic knee joints for their effective use, function, durability, and cost-effectiveness.

Prevalence of Visual Impairment and Coverage of Cataract Surgical Services: Associations with Sex, Disability, and Economic Status in Five Diverse Sites.

PURPOSE: Prevalence of visual impairment (VI) and access to services can vary significantly across and between different population groups. With renewed focus on universal health coverage and leaving no one behind, it is important to understand factors driving inequitable eye health. This paper presents results from five population-based surveys where prevalence of VI and cataract surgical coverage (CSC) were measured and examined for differences by sex, economic-status, and disability. METHODS: Rapid assessments of avoidable blindness took place in four rural sites: Kalahandi, Jhabua and Sitapur in India; and Singida, Tanzania; and one urban site: Lahore, Pakistan. In addition, the Equity Tool was used to measure economic status and the Washington Group Short Set was used to measure disability. Prevalence of VI and CSC were calculated and associations with sex, disability, and relative wealth examined. RESULTS: Prevalence of VI varied from 1.9% in Lahore to 15.0% in Kalahandi. CSC varied from 39.1% in Singida to 84.0% in Lahore. Additional disability was associated with greater levels of VI in all sites and lower CSC in Singida. Being female was associated with higher VI in Kalahandi, Lahore and Singida and lower CSC in Lahore and Singida. Being poorer was associated with higher VI in Singida and lower CSC in Singida and Sitapur. CONCLUSION: Relationships between VI and relative wealth, sex, and disability are complex and variable. Although certain characteristics may be associated with lower coverage or worse outcomes, they cannot be generalized and local data are vital to tailor services to achieve good coverage.

Integrating Geospatial Data and Measures of Disability and Wealth to Assess Inequalities in an Eye Health Survey: An Example from the Indian Sunderbans.

The Sunderbans are a group of delta islands that straddle the border between India and Bangladesh. For people living on the Indian side, health services are scarce and the terrain makes access to what is available difficult. In 2018, the international non-governmental organisation Sightsavers and their partners conducted a population-based survey of visual impairment and coverage of cataract and spectacle services, supplemented with tools to measure equity in eye health by wealth, disability, and geographical location. Two-stage cluster sampling was undertaken to randomly select 3868 individuals aged 40+ years, of whom 3410 were examined. Results were calculated using standard statistical processes and geospatial approaches were used to visualise the data. The age-sex adjusted prevalence of blindness was 0.8%, with higher prevalence among women (1.1%). Cataract Surgical Coverage for eyes at visual acuity (VA) 3/60 was 86.3%. The study did not find any association between visual impairment and wealth, however there were significant differences by additional (non-visual) disabilities at all levels of visual impairment. Geospatial mapping highlighted blocks where higher prevalence of visual impairment was identified. Integrating additional tools in population-based surveys is critical for measuring eye health inequalities and identifying population groups and locations that are at risk of being left behind.

Comparison of energy cost in transtibial amputees using "prosthesis" and "crutches without prosthesis" for walking activities.

BACKGROUND: In a survey of 100 transtibial amputees (TTA) in the study place, it was noticed that nearly 30% of total activities performed by crutches. It was recorded nearly 52% of the amputees were totally independent, 39% had to use a crutch or cane and only 9% need not used any devices simply because they are unaware of current technology or availability. Out of 39 TTA, nine used crutches only for performing daily activities while 30 used both prosthesis and crutch. Walking is a major activity in lower limb amputees and therefore it is imperative to know the energy cost in both the mobility devices (prosthesis and crutches without prosthesis) for walking activities. OBJECTIVES: The purpose of this study was to quantify and compare the difference in energy cost between the two most commonly used assistive devices (prosthesis and axillary crutches) in adults with Transtibial amputation by indirect calorimetric method at the self-selected speed in plane surface walking. METHODS: Thirty adults who had a unilateral transtibial amputation participated in this study. Oxygen consumption was measured with a Cosmed K4 b(2) oxygen analysis telemetry unit (Rome, Italy) as the participants walked over level ground for 30 meters at a self-selected speed. The variables that were analyzed were VO(2) rate (mL/min), VO(2) cost (mL/kg/m), heart rate (bpm), self-selected walking velocity (m/min) and energy expenditure per minute (Kcal/min). RESULTS: It was observed that VO(2) uptake rate and EE comparisons were highly significant for both prosthesis and crutches without prosthesis walking in adults with transtibial amputation (P<0.025). There was significant difference between prosthesis walking and crutches without prosthesis walking in terms of VO(2) uptake rate (P<0.005) and EE/min (P<0.00001). It was noticed the adults with transtibial amputation using prosthesis walked with 21% more efficient in terms of VO(2) uptake rate and 92% more efficient in terms of EE/min as compared to crutches without prosthesis. CONCLUSIONS: The data on energy cost indicates that all below knee amputee groups walk with less effort by using prosthesis. It may be concluded that crutches without prosthesis may not be used as a permanent rehabilitative measure in transtibial amputations.

Ecological problems of tree species in protected ecosystems of Orissa, India.

The tree layer vegetation of two protected ecosystems i.e. Similipal Biosphere Reserve (SBR) and Bhitarkanika National Park (BNP) of eastern ghat was analysed for structure, composition and diversity. With respect to the tree species composition the two protected ecosystems were differed from each other at the family, genera and species level. About 117 tree species representing 85 genera and 42 families were recorded in SBR. The average number of species per hectare was 32.5. However, a total of 29 tree species representing 22 genera and 16 families were recorded in BNP with an average number of species per hectare of 24.17. Species dominancy of the two protected areas was also different due to their difference in habitat condition. In SBR Shorea robusta was the most dominant species while in BNP Excoecaria agallocha was the most dominant species. Shannon-Wiener species diversity was 3.15 for Similipal and 2.314 for Bhitarkanika indicating that Similipal was highly diverse than Bhitarkanika. In general both the protected ecosystems of Orissa are highly rich in biodiversity and are characteristics of good ecological wealth of eastern ghat. Thus conservation and management practices are essential for the sustainability of their biodiversity.

Photosynthetic and fluorescence responses of Solanum melangena L. to field application of dimethoate.

The organophosphorus insecticide dimethoate, at field concentration (1.419+/-0.086mga.i.g(-1)fr.wt. of leaf tissue) did not cause any significant degradation of chlorophylls and carotenoids in Solanum melangena L. On the other hand, there was significant reduction of photosynthesis, transpiration and stomatal conductance during 6h after spray application of the insecticide. Distinct change of OJIP fluorescence transient with increase of J and I rise and corresponding decrease in P rise was observed during 6h after insecticide application. The fluorescence parameters, viz., relative variable fluorescence at J level (V(j)), net rate of PS II closure (M(0)), energy dissipation (DI(0)/RC) and maximum trapping rate of active PS II (TR(0)/RC), during the same treatment period, showed significant increase but variable fluorescence (F(v)), fluorescence yield (TR(0)/Abs), electron transport probability (ET(0)/TR(0)), and activity of RC (ET(0)/RC) showed significant decrease. All physiological and fluorescence parameters, and the OJIP fluorescence transient recovered steadily to the control level during 48h after insecticide application. There was continuous reduction in the insecticide content of the leaf tissue during the observation period.

Ancient skeletal evidence for leprosy in India (2000 B.C.).

BACKGROUND: Leprosy is a chronic infectious disease caused by Mycobacterium leprae that affects almost 250,000 people worldwide. The timing of first infection, geographic origin, and pattern of transmission of the disease are still under investigation. Comparative genomics research has suggested M. leprae evolved either in East Africa or South Asia during the Late Pleistocene before spreading to Europe and the rest of the World. The earliest widely accepted evidence for leprosy is in Asian texts dated to 600 B.C. METHODOLOGY/PRINCIPAL FINDINGS: We report an analysis of pathological conditions in skeletal remains from the second millennium B.C. in India. A middle aged adult male skeleton demonstrates pathological changes in the rhinomaxillary region, degenerative joint disease, infectious involvement of the tibia (periostitis), and injury to the peripheral skeleton. The presence and patterning of lesions was subject to a process of differential diagnosis for leprosy including treponemal disease, leishmaniasis, tuberculosis, osteomyelitis, and non-specific infection. CONCLUSIONS/SIGNIFICANCE: Results indicate that lepromatous leprosy was present in India by 2000 B.C. This evidence represents the oldest documented skeletal evidence for the disease. Our results indicate that Vedic burial traditions in cases of leprosy were present in northwest India prior to the first millennium B.C. Our results also support translations of early Vedic scriptures as the first textual reference to leprosy. The presence of leprosy in skeletal material dated to the post-urban phase of the Indus Age suggests that if M. leprae evolved in Africa, the disease migrated to India before the Late Holocene, possibly during the third millennium B.C. at a time when there was substantial interaction among the Indus Civilization, Mesopotamia, and Egypt. This evidence should be impetus to look for additional skeletal and molecular evidence of leprosy in India and Africa to confirm the African origin of the disease.

Paget's disease of bone in a 85-year-old woman.

Paget's disease of bone is a rare disorder in India. Patients are usually asymptomatic and incidental radiological investigation invariably clinches the diagnosis. Increased alkaline phosphatase, X-ray, CT scan and scintiscan of bone can be done to confirm the diagnosis. Here we report a case of an 85-yr-old lady who had bilateral hearing loss for last 10 yrs, was admitted incidentally for some other complaints and on investigation diagnosed to have advanced Paget's disease of bone.