297 research outputs found
Development of a new assessment tool for cervical myelopathy using a Virtual Reality hand tracking sensor
Introduction: Myelopathy hand is a characteristic feature of cervical myelopathy. Since there are only a few scales to quantify the severity of cervical compressive myelopathy, there is a need to introduce a universal objective platform in outpatient settings. Virtual-Reality offers promise as a means of producing quantitative data regarding the function of the neural system in the hand. The Leap Motion Controller (LMC) is a small, USB Virtual-Reality motion tracking device that could be used for this purpose. The aim of this study was to assess the reliability and validity of the LMC in the 15-second hand grip-and- release (G-R) test, as compared against human inspection of an external digital camera recording. Moreover, to set a baseline measurement of the number of hand flexion-extension cycles and analyse the degree of motion in young healthy individuals, besides examining gender and dominant hand differences. Materials and Methods: Fifty healthy participants were asked to fully grip-and-release their dominant hand as rapidly as possible for three tests, each separated by a 10-minute rest, while wearing a non-metal wrist splint. The first two tests lasted for 15 seconds, and a digital camera was used to film the anterolateral side of the hand on the first test. The third test lasted for a maximum of three minutes or until subjects fatigued. Three assessors counted the frequency of G-R cycles, of the recorded videos, independently and in a blinded fashion. One assessor counted the frequency of grip-and-release cycles as well as the number of motions (magnitude of motion) from the data output of the LMC. The average mean frequency of the three video observers was compared with that measured by LMC using the Bland-Altman method. Test-retest reliability was examined by comparing the two 15-second tests. Results: The mean number of G-R cycles recorded in each 15-second test was: 47.8 + 6.4 (test 1, video observer); 47.7 + 6.5 (test 1, LMC); and 50.2 + 6.5 (test 2, LMC). Bland Altman indicated a bias of 0.15 cycles (95%CI 1⁄4 0.10-0.20), with upper and lower limits of agreemen
A Proposed ANN-Based Acceleration Control Scheme for Soft Starting Induction Motor
In this article, a new soft starting control scheme based on an artificial neural network (ANN) is presented for a three-phase induction motor (IM) drive system. The main task of the control scheme is to keep the accelerating torque constant at a level based on the value of reference acceleration. This is accomplished by the proper choice of the firing angles of thyristors in the soft starter. Using the ANN approach, the complexity of the online determination of the thyristors firing angles is resolved. The IM torque-speed characteristic curves are firstly used to train the ANN model. Secondly, the IM- soft starter system is modeled using MATLAB/SIMULINK. To prove the effectiveness of the proposed ANN-based acceleration control scheme, different reference accelerations and loading conditions are applied and investigated. Finally, a laboratory prototype of 3 kW soft starter is implemented. The proposed control scheme is executed in a real-time environment using a digital signal processor (Model: TMS320F28335). The simulation and real-time results significantly confirm that the proposed controller can efficiently reduce the IM starting current and torque pulsations. This in turn ensures a smooth acceleration of the IM during the starting process. Moreover, the proposed control scheme has the superiority over several soft starting control schemes since it has a simple control circuit configuration, less required sensors, and low computational burden of the control algorithm. © 2021 Institute of Electrical and Electronics Engineers Inc.. All rights reserved
Optimization of dye extraction from Cordyline fruticosa via response surface methodology to produce a natural sensitizer for dye-sensitized solar cells
AbstractIn the present work, the application of response surface methodology (RSM) for the optimization of process parameters in the chlorophyll extraction from Cordyline fruticosa leaves was performed. The absorbance of the extract obtained from the extraction process under different conditions was estimated using the D-optimal design in RSM. Three different process parameters such as the nature of organic solvent based on their boiling point (ethanol, methanol, and acetonitrile), pH (4–8) and extraction temperature (50–90°C) were optimized for chlorophyll extraction. The effects of these parameters on the absorbance or concentration of the extract were evaluated using ANOVA results of quadratic polynomial regression. The results showed a high R2 and adjusted R2 correlation coefficients of 0.9963 and 0.9921 respectively. Moreover, the analysis of the final quadric model based on the design experiments indicated an optimal extraction condition of pH of 7.99, extraction temperature of 78.33°C, and a solvent boiling point, 78°C. The predicted absorbance was 1.006, which is in good agreement with the experimentally obtained result of 1.04 at 665nm wavelength. The application of pigment obtained under the optimal condition was further evaluated as a sensitizer for the dye sensitized solar cells. Maximum solar conversion efficiency (η) of 0.5% was achieved for the C. fruticosa leaf extract obtained under the optimum extraction conditions. Furthermore, the exposure of the leaf pigment to 100mW/cm2 simulated sunlight yielded a short circuit photocurrent density (Isc) of 1.3mA, open circuit voltage (Voc) of 616mV, and a fill factor (ff) of 60.16%
Recommended from our members
Relationship between serum anti-heat shock protein 27 antibody levels and obesity
Background
Heat shock protein 27 (HSP27) is an intracellular molecular chaperone that is expressed at high levels following the exposure of cells to environmental stressors such as heat, toxins, and free radicals. High levels of HSP antigens and antibody titers have been reported in several conditions including cardiovascular disease and cancers. We measured serum anti-HSP27 antibody levels in 993 subjects and assessed the associations between serum anti-HSP27 antibody levels and demographic characteristics including coronary risk factors.
Methods
A total of 993 subjects were recruited as part of the Mashhad Stroke and Heart Atherosclerotic Disorders (MASHAD) cohort study. Demographic, clinical, and biochemical parameters and serum anti-HSP27 antibody titers were determined in all the subjects.
Results
Serum anti-HSP27 antibody levels increased with increasing age in men. No significant differences in levels were detected between men and women. Serum anti-HSP27 antibody levels were significantly higher in obese subjects than in nonobese subjects (P = 0.046); however, no significant influence of smoking status was observed. Moreover, serum anti-HSP27 antibody titers were positively associated with age, body mass index, waist/hip ratio, the presence of diabetes mellitus, nonsmoking habit, serum triglycerides, cholesterol, and high-sensitivity c-reactive protein.
Conclusion
We have found that serum anti-HSP27 antibody titers are related to several cardiovascular risk factors, necessitating further studies on the value of this emerging marker for risk stratification
Recommended from our members
Depression and anxiety symptoms are associated with white blood cell count and red cell distribution width: a sex-stratified analysis in a population-based study
Background: Depression and anxiety are two important mood disorders that are frequently associated with chronic diseases such as cardiovascular diseases (CVDs). Hyper-inflammation is related to both CVDs and psychiatric conditions such as depression and anxiety. Therefore, inflammation may partially explain the relationship between depression and cardiovascular disease.
Objective: The objective of this study was to investigate the association between symptoms of depression/anxiety disorders and serum hs-CRP and inflammation linked conditions in a large Iranian population.
Methods: Symptoms of depression and anxiety disorders and serum hs-CRP levels were measured in 9,759 participants (40% males and 60% females) enrolled in MASHAD study. Symptoms of depression and anxiety were evaluated with Beck Depression and Anxiety Inventories. According to the scores of depression and anxiety, individuals were categorized into four groups of no or minimal, low, moderate and severe categories.
Results: The median serum hs-CRP concentration increased with increasing severity of depression and anxiety disorders. Male participants with severe depression had significantly higher levels of hs-CRP (p <0.001); however, this relationship was less marked among women (p = 0.04). Subjects with severe anxiety also had significantly higher levels of hs-CRP (p <0.001). Moreover, women with severe depression and anxiety had higher BMI. There was also a positive association between current smoking habit and depression/anxiety disorders.
Conclusion: Depression and anxiety disorders are associated with elevated levels of hs-CRP, particularly among men. There were also a significant positive association between depression/anxiety disorders and inflammation linked conditions such as smoking and obesity; however, in the case of obesity this association was only present in women
Averrhoa carambola leaves prevent dyslipidemia and oxidative stress in a rat model of poloxamer-407-induced acute hyperlipidemia
Background: The star fruit [Averrhoa carambola L (Oxalidaceae)] is traditionally used in the treatment of many ailments in many countries. It possesses several pharmacological activities, including antioxidant and anti-inflammatory effects. However, it contains the neurotoxic caramboxin and its high content of oxalic acid limits its consumption by individuals with compromised kidney function. This study assessed the anti-hyperlipidemic and antioxidant activities of different fractions of the methanolic extract of A. carambola leaves (MEACL).Methods: The antioxidant activity was investigated using FRAP, and ABTS and DPPH radical-scavenging assays and the inhibitory activity toward pancreatic lipase (PL) and HMG-CoA reductase was assayed in vitro. Acute hyperlipidemia was induced by poloxamer-407 (P-407) in rats and different fractions of MEACL (n-hexane, chloroform, n-butanol, ethyl acetate (EA), water, and chloroform) were orally administered. Cholesterol and triglycerides were determined at 0, 12, 24, and 48 h and LDL-C, vLDL-C, HDL-C, lipid peroxidation (LPO) and antioxidants were assayed after 48 h. The expression of ABCA1, ABCG5, ABCG8, LDL-R, SREBP-1, and SREBP-2 and the activity of HMG-CoA reductase were assayed in the liver of P-407-administered rats treated with the EA fraction.Results: The in vitro data revealed potent radical-scavenging activities of MEACL fractions with the most potent effect showed by the EA fraction that also suppressed the activities of HMG-CoA reductase and PL. In P-407-induced hyperlipidemic rats, all fractions prevented dyslipidemia as shown by the decrease in total cholesterol, triglycerides, LDL-C, vLDL-C and atherogenic index. MEACL and its fractions prevented LPO and boosted GSH, superoxide dismutase, glutathione peroxidase, and catalase in P-407-administered rats. The EA fraction showed more effective anti-hyperlipidemic and antioxidant effects than other fractions and downregulated SREBP-2 while upregulated ABCA1 and LDL-R and ameliorated LPL and HMG-CoA reductase in hyperlipidemic rats.Conclusion: MEACL showed in vitro and in vivo antioxidant activity and the EA fraction significantly ameliorated dyslipidemia in a rat model of P-407-induced acute hyperlipidemia by modulating LPL, PL, HMG-CoA reductase, and cholesterolgenesis-related factors. Therefore, the leaves of A. carambola represent a safe alternative for the star fruit particularly in kidney disease patients, and the EA is the most effective anti-hyperlipidemic and antioxidant fraction
Mechanisms of simvastatin myotoxicity: The role of autophagy flux inhibition.
Statins are some of the most widely used drugs worldwide, but one of their major side effects is myotoxicity. Using mouse myoblast (C2C12) and human alveolar rhabdomyosarcoma cell lines (RH30) in both 2-dimensional (2D) and 3-dimensional (3D) cell culture, we investigated the mechanisms of simvastatin\u27s myotoxicity. We found that simvastatin significantly reduced cell viability in C2C12 cells compared to RH30 cells. However, simvastatin induced greater apoptosis in RH30 compared to C2C12 cells. Simvastatin-induced cell death is dependent on geranylgeranyl pyrophosphate (GGPP) in C2C12 cells, while in RH30 cells it is dependent on both farnesyl pyrophosphate (FPP) and GGPP. Simvastatin inhibited autophagy flux in both C2C12 and RH30 cells and inhibited lysosomal acidification in C2C12 cells, while autophagy inhibition with Bafilomycin-A1 increased simvastatin myotoxicity in both cell lines. Simvastatin induced greater cell death in RH30 cells compared to C2C12 in a 3D culture model with similar effects on autophagy flux as in 2D culture. Overall, our results suggest that simvastatin-induced myotoxicity involves both apoptosis and autophagy, where autophagy serves a pro-survival role in both cell lines. The sensitivity to simvastatin-induced myotoxicity differs between 2D and 3D culture, demonstrating that the cellular microenvironment is a critical factor in regulating simvastatin-induced cell death in myoblasts
A comparative randomized clinical trial evaluating the efficacy and safety of tacrolimus versus hydrocortisone as a topical treatment of atopic dermatitis in children
Background: Atopic dermatitis (AD) aetiology is not exactly identified, but it is characterized by pruritic skin reactions with elevation in the levels of inflammatory markers. Despite the fact that Corticosteroids are the mainstay therapy in the management of AD, they have many local and systemic adverse effects.Objective: The aim of this study is to evaluate the efficacy and safety of topical tacrolimus ointment in comparison to topical hydrocortisone cream in the management of the AD of children diagnosed with AD.Patients and Methods: This study was conducted on 200 children with AD. They were simply randomized into two groups, the tacrolimus group treated with 0.03% topical tacrolimus ointment and the hydrocortisone group treated with 1% hydrocortisone cream twice daily during the 3 weeks study period.Results: At the end of the study, both the tacrolimus and hydrocortisone groups showed a significant decline in the mean serum level of IL-10, IL-17, and IL-23 (p < 0.05) when compared to their baseline levels. However, the tacrolimus group showed a more significant decrease (p < 0.05) in the mean serum level of IL-10, IL-17, and IL-23 as compared to the hydrocortisone group [Mean differences = 1.600, 95% CI: 0.9858–2.214; 1.300, 95% CI: 1.086–1.514 and 4.200, 95% CI: 3.321–5.079]. Moreover, the median mEASI decreased similarly from 32 to 21 in the tacrolimus group and from 30 to 22 in the hydrocortisone group (p > 0.05) [Median difference = −2.000, 95% CI: −2.651 to −1.349; Median difference = 1.000, 95% CI: 0.3489–1.651]. Mild to moderate transient stinging and erythema were the main adverse effects that showed higher incidence in the tacrolimus group than in the hydrocortisone group (p < 0.05). In most cases, they resolved within 3–4 days. Besides, tacrolimus ointment did not cause skin atrophy as compared to the hydrocortisone group (p < 0.05).Conclusion: Tacrolimus ointment is more beneficial than hydrocortisone cream in managing AD in children in terms of lowering the inflammatory markers, however, there is no difference on the dermatitis severity scale. Moreover, tacrolimus is safer with a better side effect profile compared to hydrocortisone.Trial Registration: The trial is registered at ClinicalTrials.gov (CT.gov identifier: NCT05324618
Characterizing genomic alterations in cancer by complementary functional associations.
Systematic efforts to sequence the cancer genome have identified large numbers of mutations and copy number alterations in human cancers. However, elucidating the functional consequences of these variants, and their interactions to drive or maintain oncogenic states, remains a challenge in cancer research. We developed REVEALER, a computational method that identifies combinations of mutually exclusive genomic alterations correlated with functional phenotypes, such as the activation or gene dependency of oncogenic pathways or sensitivity to a drug treatment. We used REVEALER to uncover complementary genomic alterations associated with the transcriptional activation of β-catenin and NRF2, MEK-inhibitor sensitivity, and KRAS dependency. REVEALER successfully identified both known and new associations, demonstrating the power of combining functional profiles with extensive characterization of genomic alterations in cancer genomes
- …