Wearable and flexible thin film thermoelectric module for multi-scale energy harvesting

Developing a thermoelectric generator(TEG) with shape conformable geometry for sustaining low-thermal impedance and large temperature gradient (ΔT) is fundamental for wearable and multi-scale energy harvesting applications. Here we demonstrate a flexible architectural design, with efficient thin film thermoelectric generator as a solution for this problem. This approach not only decreases the thermal impedance but also multiplies the temperature gradient, thereby increasing the power conversion efficiency (PCE) as comparable to bulk TEG. Intact thin films of Tin telluride (p-type) and Lead Telluride (n-type) are deposited on flexible substrate through physical vapor deposition and a thermoelectric module possessing a maximum output power density of 8.4 mW/cm2 is fabricated. We have demonstrated the performance of p-SnTe/n-PbTe based TEG as a flexible wearable power source for electronic gadgets, as a thermal touch sensor for real-time switching and temperature monitoring for exoskeleton applications

Role of matrix metalloproteinases in multi-system inflammatory syndrome and acute COVID-19 in children

INTRODUCTION: Multisystem Inflammatory Syndrome in children (MIS-C) is a serious inflammatory sequela of SARS-CoV2 infection. The pathogenesis of MIS-C is vague and matrix metalloproteinases (MMPs) may have an important role. Matrix metalloproteinases (MMPs) are known drivers of lung pathology in many diseases. METHODS: To elucidate the role of MMPs in pathogenesis of pediatric COVID-19, we examined their plasma levels in MIS-C and acute COVID-19 children and compared them to convalescent COVID-19 and children with other common tropical diseases (with overlapping clinical manifestations). RESULTS: Children with MIS-C had elevated levels of MMPs (P < 0.005 statistically significant) in comparison to acute COVID-19, other tropical diseases (Dengue fever, typhoid fever, and scrub typhus fever) and convalescent COVID-19 children. PCA and ROC analysis (sensitivity 84–100% and specificity 80–100%) showed that MMP-8, 12, 13 could help distinguish MIS-C from acute COVID-19 and other tropical diseases with high sensitivity and specificity. Among MIS-C children, elevated levels of MMPs were seen in children requiring intensive care unit admission as compared to children not needing intensive care. Similar findings were noted when children with severe/moderate COVID-19 were compared to children with mild COVID-19. Finally, MMP levels exhibited significant correlation with laboratory parameters, including lymphocyte counts, CRP, D-dimer, Ferritin and Sodium levels. DISCUSSION: Our findings suggest that MMPs play a pivotal role in the pathogenesis of MIS-C and COVID-19 in children and may help distinguish MIS-C from other conditions with overlapping clinical presentation

Unique cellular immune signatures of multisystem inflammatory syndrome in children

The clinical presentation of MIS-C overlaps with other infectious/non-infectious diseases such as acute COVID-19, Kawasaki disease, acute dengue, enteric fever, and systemic lupus erythematosus. We examined the ex-vivo cellular parameters with the aim of distinguishing MIS-C from other syndromes with overlapping clinical presentations. MIS-C children differed from children with non-MIS-C conditions by having increased numbers of naïve CD8(+) T cells, naïve, immature and atypical memory B cells and diminished numbers of transitional memory, stem cell memory, central and effector memory CD4(+) and CD8(+) T cells, classical, activated memory B and plasma cells and monocyte (intermediate and non-classical) and dendritic cell (plasmacytoid and myeloid) subsets. All of the above alterations were significantly reversed at 6–9 months post-recovery in MIS-C. Thus, MIS-C is characterized by a distinct cellular signature that distinguishes it from other syndromes with overlapping clinical presentations. Trial Registration: ClinicalTrials.gov clinicaltrial.gov. No: NCT04844242

Sphingolipids as critical players in retinal physiology and pathology

Sphingolipids have emerged as bioactive lipids involved in the regulation of many physiological and pathological processes. In the retina, they have been established toparticipate in numerousprocesses, suchas neuronal survival and death, proliferation and migration of neuronal and vascular cells, inflammation, and neovascularization. Dysregulation of sphingolipids is therefore crucial in the onset and progression of retinal diseases. This review examines the involvement of sphingolipids in retinal physiology and diseases. Ceramide (Cer) has emerged as a common mediator of inflammation and death of neuronal and retinal pigment epithelium cells in animal models of retinopathies such as glaucoma, age-related macular degeneration (AMD), and retinitis pigmentosa. Sphingosine- 1-phosphate (S1P) has opposite roles, preventing photoreceptor and ganglion cell degeneration but also promoting inflammation, fibrosis, and neovascularization in AMD, glaucoma, and pro-fibrotic disorders. Alterations in Cer, S1P, and ceramide 1- phosphate may also contribute to uveitis. Notably, use of inhibitors that either prevent Cer increase or modulate S1P signaling, such as Myriocin, desipramine, and Fingolimod (FTY720), preserves neuronal viability and retinal function. These findings underscore the relevance of alterations in the sphingolipid metabolic network in the etiology of multiple retinopathies and highlight the potential of modulating their metabolism for the design of novel therapeutic approaches.Fil: Simon, Maria Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones Bioquímicas de Bahía Blanca. Universidad Nacional del Sur. Instituto de Investigaciones Bioquímicas de Bahía Blanca; Argentina. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia; ArgentinaFil: Basu, Sandip K.. University of Tennessee; Estados UnidosFil: Qaladize, Bano. University of Tennessee; Estados UnidosFil: Grambergs, Richards. University of Tennessee; Estados UnidosFil: Rotstein, Nora Patricia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones Bioquímicas de Bahía Blanca. Universidad Nacional del Sur. Instituto de Investigaciones Bioquímicas de Bahía Blanca; Argentina. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia; ArgentinaFil: Mandal, Nawajes .A.. University of Tennessee; Estados Unido

Numerical solution of Stokes problem for free convection effects in dissipative dusty medium

The flow past an infinite vertical isothermal plate started impulsively in its own plane in a viscous incompressible two-phase fluid has been considered by taking into account the viscous dissipative heat. The coupled nonlinear equations governing the flow are solved for fluid and particle phases by finite difference method. The velocity and temperature fields have been shown graphically for G being positive for dusty air and it was observed that the same results hold for water. (G denotes the Grashof number and G>0 corresponds to cooling of the plate by free convection currents.) The results for G<0 (heating of the plate) have been verified and discussed. The numerical values of skin friction and the rate of heat transfer of dusty fluid are shown in tables. The effects of G and E (the Eckert number) on the flow field are discussed. It is observed that dusty fluid causes an increase in skin friction. The increase in mass concentration of dust particles decreases the heat transfer rate. The presence of inert particles does not admit the reverse type of flow even for large values of t

Low Flow Trends in Texas Stream Segments Serving Unique Hydrologic Functions

In recognition of the unique hydrologic functions they serve, certain stream segments in Texas have been designated as ecologically significant. In this study, we evaluated low flow trends in seven hydrologically unique stream segments spanning three climatic divisions in Texas from 1970 to 2019. Despite increasing mean annual temperatures, there are no trends in low flows or other hydrologic variables in the East Fork of the San Jacinto River in the Upper Coast climatic division, likely due to local moisture surplus effects from the Gulf of Mexico. In the Edwards Plateau climatic division, annual low flows and annual baseflows are decreasing in the South Fork of the Guadalupe River, the Sabinal River and the Frio River. While increasing mean annual temperatures appear to have a role in the drying of all three of these stream segments, increasing annual potential evapotranspiration may be an additional driver in the Sabinal and Frio Rivers. Analysis of the Standardized Streamflow Index indicates that all seven stream segments experienced their worst streamflow droughts in the 2010s. As such, the watersheds draining to the gages on these stream segments have minimal anthropogenic impacts, suggesting the influence of climate on the observed stream drying

Low Flow Trends in Texas Stream Segments Serving Unique Hydrologic Functions

In recognition of the unique hydrologic functions they serve, certain stream segments in Texas have been designated as ecologically significant. In this study, we evaluated low flow trends in seven hydrologically unique stream segments spanning three climatic divisions in Texas from 1970 to 2019. Despite increasing mean annual temperatures, there are no trends in low flows or other hydrologic variables in the East Fork of the San Jacinto River in the Upper Coast climatic division, likely due to local moisture surplus effects from the Gulf of Mexico. In the Edwards Plateau climatic division, annual low flows and annual baseflows are decreasing in the South Fork of the Guadalupe River, the Sabinal River and the Frio River. While increasing mean annual temperatures appear to have a role in the drying of all three of these stream segments, increasing annual potential evapotranspiration may be an additional driver in the Sabinal and Frio Rivers. Analysis of the Standardized Streamflow Index indicates that all seven stream segments experienced their worst streamflow droughts in the 2010s. As such, the watersheds draining to the gages on these stream segments have minimal anthropogenic impacts, suggesting the influence of climate on the observed stream drying

On-off attack detection in trust model using intra-daily variability for the IoT

The growth of the internet of things (IoT) increases the need to develop the trust computational model for heterogeneous networks with various IoT devices. Trust models are considered as an effective tool to mitigate insider attacks induced by IoT devices. However, trust models are exposed to on-off attacks, in which devices randomly exhibit good and bad behaviors to avoid being categorized as low-trust devices. The objective of this work is to recognize the malicious devices executing on-off attacks in IoT applications. This paper introduces an on-off attack detection strategy for the trust computational model based on the non-parametric index named intra-daily variability (IV). IV indicates trust fragmentation which depends on the frequency and the transitions between periods of low and high trust values of a device. The higher value of IV indicates the occurrence of fragmented trust values and the lower value of IV indicates the occurrence of non-fragmented trust values. Experimental results show that the proposed model outperforms the baseline methods by increasing the on-off attack detection rate