Nevin Manimala

Results Phys. 2021 Mar;22:103956. doi: 10.1016/j.rinp.2021.103956. Epub 2021 Feb 18.

ABSTRACT

It is of great curiosity to observe the effects of prevention methods and the magnitudes of the outbreak including epidemic prediction, at the onset of an epidemic. To deal with COVID-19 Pandemic, an SEIQR model has been designed. Analytical study of the model consists of the calculation of the basic reproduction number and the constant level of disease absent and disease present equilibrium. The model also explores number of cases and the predicted outcomes are in line with the cases registered. By parameters calibration, new cases in Pakistan are also predicted. The number of patients at the current level and the permanent level of COVID-19 cases are also calculated analytically and through simulations. The future situation has also been discussed, which could happen if precautionary restrictions are adopted.

PMID:33623733 | PMC:PMC7889458 | DOI:10.1016/j.rinp.2021.103956

Results Phys. 2021 Feb 19:103976. doi: 10.1016/j.rinp.2021.103976. Online ahead of print.

ABSTRACT

One of the greatest challenges facing the humankind nowadays is to confront that emerging virus, which is the Coronavirus (COVID-19), and therefore all organizations have to unite in order to tackle that the transmission risk of this virus. From this standpoint, the scientific researchers have to find good mathematical models that do describe the transmission of such virus and contribute to reducing it in one way or another, where the study of COVID-19 transmission dynamics by mathematical models is very important for analyzing and controlling this disease propagation. Thus, in the current work, we present a new fractional-order mathematical model that describes the dynamics of COVID-19. In the proposed model, the total population is divided into eight classes, in addition to three compartments used to estimate the parameters and initial values. The effective reproduction number ( R0 ) is derived by next generation matrix (NGM) method and all possible equilibrium points and their stability are investigated in details. We used the reported data (from January 23, 2020, to November 21, 2020) from the National Health Commission (NHC) of China to estimate the parameters and initial conditions (ICs) which suggested for our model. Simulation outcomes demonstrate that the fractional order model (FOM) represents behaviors that follow the real data more accurately than the integer-order model. The current work enhances the recent reported results of Zu et al. published in THE LANCET (doi:10.2139/ssrn.3539669).

PMID:33623732 | PMC:PMC7892305 | DOI:10.1016/j.rinp.2021.103976

Results Phys. 2021 Feb 19:103913. doi: 10.1016/j.rinp.2021.103913. Online ahead of print.

ABSTRACT

In this paper we consider ant-eating pangolin as a possible source of the novel corona virus (COVID-19) and propose a new mathematical model describing the dynamics of COVID-19 pandemic. Our new model is based on the hypotheses that the pangolin and human populations are divided into measurable partitions and also incorporates pangolin bootleg market or reservoir. First we study the important mathematical properties like existence, boundedness and positivity of solution of the proposed model. After finding the threshold quantity for the underlying model, the possible stationary states are explored. We exploit linearization as well as Lyapanuv function theory to exhibit local stability analysis of the model in terms of the threshold quantity. We then discuss the global stability analyses of the newly introduced model and found conditions for its stability in terms of the basic reproduction number. It is also shown that for certain values of R0 , our model exhibits a backward bifurcation. Numerical simulations are performed to verify and support our analytical findings.

PMID:33623730 | PMC:PMC7892304 | DOI:10.1016/j.rinp.2021.103913

Geriatr Orthop Surg Rehabil. 2021 Feb 9;12:2151459321991503. doi: 10.1177/2151459321991503. eCollection 2021.

ABSTRACT

In patients over 65y.o. who were surgically treated for a hip fracture, electrolytes have not been specifically studied as predictors of mortality. The main purpose of this study was to assess whether electrolytes and chronic kidney disease (CKD) stages, evaluated at admission, could represent a pre-operative prognostic factor in this population. Moreover, the role of epidemiological and clinical parameters was analyzed with and without a surgical timing stratification. This retrospective study included 746 patients. For each patient, their age, gender, fracture classification, Hb value, comorbidities, ASA class, chronic kidney disease, creatinine levels, electrolytes and surgical timing were collected. CKD-epi, MDRD, modified MDRD and BIS1 were used to obtain eGFR and CKD stages. All parameters were analyzed individually and in relation to the different surgical timing. Descriptive statistics, Chi-square test and survivability analysis with Kaplan Meier curve were used. In patients with a hip fracture non-significant association with increased mortality was shown for the following variables: Hb value, sodium values, calcium values, CKD stages and creatinine values. Otherwise altered kalemia was associated with a statistically significant increase in mortality as well as male gender, two or more comorbid medical conditions, advanced age (>75 years), higher ASA class. Surgery performed within 72h resulted in a statistically significant reduction in mortality at 6 months and, when performed in 24h-48h, a further reduction at 4 years. Age and ASA class statistically significant increased mortality regardless the surgical timing. Male patients operated after 48h from hospitalization were associated with a statistically significant increase in mortality rate. Two or more comorbidities were related to a statistically significant increased number of deaths when patients were treated after 96h. Altered kalemia values at hospitalization are associated with a statistically significant increase in mortality in patients operated after 72h from admission.

PMID:33623723 | PMC:PMC7876745 | DOI:10.1177/2151459321991503

J Magn Reson Imaging. 2021 Feb 24. doi: 10.1002/jmri.27542. Online ahead of print.

ABSTRACT

BACKGROUND: Clinical examination and lymphoscintigraphy are the current standard for investigating lymphatic function. Magnetic resonance imaging (MRI) facilitates three-dimensional (3D), nonionizing imaging of the lymphatic vasculature, including functional assessments of lymphatic flow, and may improve diagnosis and treatment planning in disease states such as lymphedema.

PURPOSE: To summarize the role of MRI as a noninvasive technique to assess lymphatic drainage and highlight areas in need of further study.

STUDY TYPE: Systematic review.

POPULATION: In October 2019, a systematic literature search (PubMed) was performed to identify articles on magnetic resonance lymphangiography (MRL).

FIELD STRENGTH/SEQUENCE: No field strength or sequence restrictions.

ASSESSMENT: Article quality assessment was conducted using a bespoke protocol, designed with heavy reliance on the National Institutes of Health quality assessment tool for case series studies and Downs and Blacks quality checklist for health care intervention studies.

STATISTICAL TESTS: The results of the original research articles are summarized.

RESULTS: From 612 identified articles, 43 articles were included and their protocols and results summarized. Field strength was 1.5 or 3.0 T in all studies, with 25/43 (58%) employing 3.0 T imaging. Most commonly, imaging of the peripheries, upper and lower limbs including the pelvis (32/43, 74%), and the trunk (10/43, 23%) is performed, including two studies covering both regions. Imaging protocols were heterogenous; however, T₂ -weighted and contrast-enhanced T₁ -weighted images are routinely acquired and demonstrate the lymphatic vasculature. Edema, vessel, quantity and morphology, and contrast uptake characteristics are commonly reported indicators of lymphatic dysfunction.

DATA CONCLUSION: MRL is uniquely placed to yield large field of view, qualitative and quantitative, 3D imaging of the lymphatic vasculature. Despite study heterogeneity, consensus is emerging regarding MRL protocol design. MRL has the potential to dramatically improve understanding of the lymphatics and detect disease, but further optimization, and research into the influence of study protocol differences, is required before this is fully realized.

LEVEL OF EVIDENCE: 2 TECHNICAL EFFICACY: Stage 2.

PMID:33625795 | DOI:10.1002/jmri.27542

Vet Surg. 2021 Feb 24. doi: 10.1111/vsu.13594. Online ahead of print.

ABSTRACT

OBJECTIVE: To describe medium-term functional outcome after nail osteosynthesis in feline traumatology and report clinically relevant recommendations for I-Loc angle-stable interlocking nail use in cats.

STUDY DESIGN: Prospective clinical study.

SAMPLE POPULATION: Client-owned cats (n = 29).

METHODS: Consecutive cases with femoral, tibial, or humeral fractures were included. Outcome measures included fracture and surgical procedure description, limb alignment, nail size vs body weight (BW), percentage of nail medullary canal (MC) fill, time to limb function at clinical union (CU), and complications. Descriptive statistics were reported and compared with historical data.

RESULTS: Bone distribution was 53.3% femora, 30% tibiae, and 16.7% humeri. There were six epimetaphyseal and 24 diaphyseal fractures. Overall, 67% of fractures were comminuted. Open reduction and minimally invasive techniques were used in 73% and 27% of cases, respectively. Seventeen I-Loc 3 (cat mean BW 4.4 ± 2.2 kg) and 13 I-Loc 4 (cat mean BW 5.2 ± 1.2 kg) nails were placed with mean MC fill of ≤50%. Average time to CU was 7.2 weeks. At CU, lameness had resolved or was mild in every cat, and all cats ultimately regained full limb function. No major complications were encountered.

CONCLUSION: Because of improved CU times, excellent functional outcomes, and low complication rate, our results provide evidence that I-Loc nails are safe and effective for feline traumatology.

CLINICAL SIGNIFICANCE: The I-Loc may be advantageous for fixation of epimetaphyseal fractures. Because of feline bone specific dimensional constraints, I-Loc 3 is likely appropriate for all feline humeri and most tibiae, while I-Loc 4 is well sized for feline femora.

PMID:33625791 | DOI:10.1111/vsu.13594

Diabetes Obes Metab. 2021 Feb 24. doi: 10.1111/dom.14363. Online ahead of print.

ABSTRACT

AIMS: To explore early effects of dapagliflozin on myocardial function and metabolism in patients with type 2 diabetes without heart failure.

MATERIALS AND METHODS: Patients with type 2 diabetes on metformin treatment were randomized to double-blind 6-week placebo or dapagliflozin 10 mg daily treatment. Investigations included cardiac function and structure with myocardial resonance imaging (MRI); cardiac oxygen consumption, perfusion and efficiency with [¹¹ C]-acetate positron emission tomography (PET); and cardiac and hepatic fatty acid uptake with [¹⁸ F]-FTHA PET, analyzed by ANCOVA as least square means with 95% confidence intervals.

RESULTS: Evaluable patients (placebo: n = 24, dapagliflozin: n = 25; 53% males) had mean age 64.4 years, BMI 30.2 kg/m² , and HbA1c 6.7%. Body weight and HbA1c were significantly decreased by dapagliflozin vs placebo. Dapagliflozin had no effect on myocardial efficiency, but external left ventricular (LV) work -0.095 (-0.145, -0.043) J/g/min, and LV oxygen consumption were significantly reduced -0.30 (-0.49, -0.12) J/g/min by dapagliflozin, but changes were not statistically significant vs changes in placebo group. Change in left atrial maximal volume with dapagliflozin vs placebo was -3.19 (-6.32, -0.07) mL/m² , p = 0.056. Peak global radial strain decreased with dapagliflozin vs placebo, -3.92 (-7.57, -0.28) %, p = 0.035; peak global longitudinal and circumferential strains were unchanged. Hepatic fatty acid uptake was increased by dapagliflozin vs placebo, 0.024 (0.004, 0.044) μmol/g/min, p = 0.018, while cardiac uptake was unchanged.

CONCLUSIONS: This exploratory study indicates reduced heart work but limited effects on myocardial function, efficiency, and cardiac fatty acid uptake, while hepatic fatty acid uptake increased, after 6 weeks treatment with dapagliflozin.

CLINICAL TRIAL REGISTRATION: NCT03387683. This article is protected by copyright. All rights reserved.

PMID:33625777 | DOI:10.1111/dom.14363

J Magn Reson Imaging. 2021 Feb 24. doi: 10.1002/jmri.27568. Online ahead of print.

ABSTRACT

BACKGROUND: Longitudinal magnetic resonance imaging (MRI) studies have become increasingly important to assess the changes in brain morphology during normal aging and neurodegenerative disorders. However, the reliability of longitudinal morphometric changes has not been fully evaluated.

PURPOSE: To examine the reliability of longitudinal (2-year) changes in brain morphology determined by longitudinal voxel-based morphometry (VBM) in healthy elderly subjects, patients with mild cognitive impairment (MCI), and patients with Alzheimer’s disease (AD).

STUDY TYPE: Retrospective analysis.

SUBJECTS: Twenty-four healthy elderly subjects, 28 MCI patients, and 16 AD patients.

FIELD STRENGTH/SEQUENCE: A 1.5 T, magnetization-prepared rapid gradient-echo.

ASSESSMENT: Longitudinal (2-year) changes in gray matter volume determined by longitudinal VBM processing, and visual assessment of image quality.

STATISTICAL TESTS: Intraclass correlation coefficient (ICC) and Kruskal-Wallis test.

RESULTS: The ICC maps differed among the three groups. The mean ICC was 0.81 overall (0.86 for healthy elderly subjects, 0.75 for MCI patients, and 0.76 for AD patients). The reliability was good to excellent (ICC, 0.60-1.00) for 92% of voxels (99% for healthy elderly subjects, 83% for MCI patients, and 83% for AD patients). The image quality differed significantly among the three groups (P < 0.05).

DATA CONCLUSION: These results indicate that the reliability of longitudinal gray matter volume changes by VBM is good to excellent for most voxels. However, reliability may be affected by the disease, possibly due to differences in head motion during imaging. Evidence Level 3 Technical Efficacy Stage 1.

PMID:33625755 | DOI:10.1002/jmri.27568

Environ Sci Pollut Res Int. 2021 Feb 24. doi: 10.1007/s11356-021-12661-y. Online ahead of print.

ABSTRACT

This study analyses the long-run effects of economic growth, energy consumption and financial development on carbon dioxide (CO₂) emissions in Turkey using annual time series data for the period 1965-2018. This research investigates the relationship between the variables using a RALS-EG (residual augmented least squares-Engle and Granger) cointegration test procedure developed by Lee et al. Stud Nonlinear Dyn Econ 19:397-413, (2015). In addition, this study uses a bootstrap causality analysis developed by Hacker and Hatemi-J J Econ Stud 39:144-160, (2012) to specify the causal relationship between the series. RALS cointegration test results show a long-run relationship between CO₂ emissions and economic growth, energy consumption and financial development. According to a dynamic ordinary least squares estimation, economic growth has a negative and statistically significant effect on CO₂ emissions, whereas energy consumption and financial development have positive and statistically significant effects on CO₂ emissions in the long run. In particular, energy consumption is the most effective parameter of environmental pollution in Turkey. However, the causality test results indicate a unidirectional causal relationship from financial development to CO₂ emissions, economic growth and energy consumption. Increasing the investment in renewable energy sources will be an effective policy tool to improve the environmental quality in Turkey.

PMID:33625708 | DOI:10.1007/s11356-021-12661-y

Environ Sci Pollut Res Int. 2021 Feb 24. doi: 10.1007/s11356-021-12894-x. Online ahead of print.

ABSTRACT

The last mile connectivity through public transport is a challenging task in India. However, according to the Society of Indian Automotive Manufacturers (SIAM) statistics, three-wheelers sales increased by 10.27% in the year financial year of 2018-2019 compared to the previous financial year. In this growth, it is recorded that the passenger carrier three-wheeler sales increased by 10.62% and goods carrier three-wheeler grew by 8.75% in the year 2019 compared to the previous year. The existing design consideration in the three-wheeler development shows poor performance in the real-world scenario because the three-wheeler’s open drive compartment creates more aerodynamic drag to the vehicle. This increases the amount of energy consumption to achieve the same amount of range (km/L). Three-wheeler’s extra energy consumption will directly increase the amount of exhaust emission in internal combustion engines and electrical energy consumption in electric vehicles. The present paper attempts in designing a solar-powered electrical auto-rickshaw for rural transportation. The paper aims to obtain an optimal solar module placement angle and analyzes the solar-powered electrical auto-rickshaw performance by incorporating the National Advisory Committee for Aeronautics (NACA) aerodynamic design principles. The optimal solar module placement angle is identified by analyzing the various configurations like front alone tilt at 16°-degree, rear alone tilt at the 5°-degree and combined front at 16°-degree, and rear at 5°-degree to reduce the aerodynamic drag effect. The paper also aims to identify the effect of the optimal angle on vehicle speed, and solar power generation to enhance the performance and energy efficiency for achieving environmentally sustainable transportation.

PMID:33625701 | DOI:10.1007/s11356-021-12894-x