Disruption Of Layer Research Articles

Exposure to Airborne Particulate Matter and Undernutrition in Young Rats: An In-Depth Histopathological and Biochemical Study on Lung and Excretory Organs.

Environmental stressors, such as air particulate matter (PM) and nutrient deficiencies, can significantly impact crucial organs involved in detoxifying xenobiotics, including lungs, liver, and kidneys, especially in vulnerable populations like children. This study investigated the effect of 4-week exposure to Residual Oil Fly Ash (ROFA) on these organs in young rats under growth-restricted nutrition (NGR). We assessed histological, histomorphometric and biochemical parameters. ROFA exposure induced histological changes and inflammation in all three organs when compared to control (C) animals. Specifically, in lungs ROFA caused a significant reduction in alveolar airspace (C: 55.8±1.8% vs. ROFA: 38.7±3.0%, p<0.01) and alveolar number along with changes in alveolar size distribution, and disruption of the smooth muscle layer which may impaired respiratory function. In the liver, ROFA increased: binucleated cells, macro and microvesicles and both AST and ALT serum biomarkers (AST: C=77.7±1.3 vs. ROFA=81.6±1.3, p<0.05; ALT: C=44.5±0.9 vs. ROFA=49.4±1.3, p<0.05). In the kidneys, a reduced Bowman's space (C: 2.15±0.2 mm2 vs. ROFA: 1.74±0.2 mm2, p<0.05) was observed, indicative of glomerular filtration failure. NGR alone reduced Bowman's space (C: 2.15±0.2 mm2 vs. NGR: 1.06±0.1 mm2, p<0.001). In lung and liver NGR showed higher levels of proinflammatory cytokine IL-6 (p<0.01 and p<0.001, respectively) when compared to C. In conclusion, both stressors negatively affected lung and excretory organs in young rats, with nutritional status further modulating the physiological response to ROFA. These findings highlight the compounded risks posed by environmental pollutants and poor nutrition in vulnerable populations.

Clinical Characterization, Natural History, and Detailed Phenotyping of NMNAT1-Associated Leber Congenital Amaurosis.

To characterize the clinical phenotype and disease progression in patients with NMNAT1-associated Leber congenital amaurosis (LCA) within the Korean population. Retrospective, observational case series. Fourteen patients with LCA with biallelic variants of NMNAT1 at a single tertiary referral center. Electronic medical records were reviewed for medical history, ophthalmic examinations, and molecular diagnoses, both cross-sectionally and longitudinally. Ophthalmic examination findings were evaluated and retinal phenotypic characteristics were assessed using multimodal imaging. All patients exhibited early-onset, rapidly progressive bilateral retinal degeneration with pronounced central involvement. The condition was characterized by multiple atrophic lesions that coalesced into a large central retinal scar by age 2. The condition stabilized around 4 years of age. Fluorescein angiography demonstrated central hypofluorescence with visible choroidal vasculature. Optical coherence tomography showed significant retinal thinning, outer retinal layer disruption, and retinal pigment epithelial atrophy. Most patients maintained light perception vision or better, with minimal deterioration of visual acuity after the age of 2. All patients were hyperopic and exhibited undetectable electroretinography and visual-evoked potential responses. NMNAT1-associated LCA is characterized by severe, early-onset retinal degeneration with rapid progression, followed by stabilization. This distinct temporal pattern of disease progression suggests a potential therapeutic window in early childhood, emphasizing the importance of early diagnosis and regular monitoring for potential interventions.

Atypical COVID-19-Related Acute Macular Neuroretinopathy with Progression Resulting in Severe Vision Loss

Introduction: We review the clinical course of a patient with decreased vision in the setting of COVID-19 infection consistent with an atypical presentation of acute macular neuroretinopathy (AMN). Case Presentation: A 56-year-old Caucasian woman developed a scotoma in the right eye 3 days after COVID-19 diagnosis and in her left eye on day 5. Baseline exam showed significantly reduced visual acuity bilaterally best corrected visual acuity of 20/60 in the right eye and 20/40 in the left eye from a patient-reported baseline of 20/20 in each eye. Examination of the fundus was remarkable for small flame-shaped hemorrhages in the superior arcade of both eyes. Near-infrared reflectance imaging revealed a singular wedge-shaped lesion in each eye close to the fovea and spectral domain-optical coherence tomography confirmed disruption of the photoreceptor layer and ellipsoid zones. Our leading diagnosis given the presentation was COVID-19-associated AMN. Given no evidence of a clear treatment, observation was selected. Three weeks later, visual acuity deteriorated further to 20/100 OD and 20/80 OS, with persistence of the wedge-shaped lesions. At 3-month follow-up, fundus photographs remained unremarkable; however, visual acuity had dropped further to 20/300 bilaterally, with persistence of the scotomata and outer retinal layer disruptions. 6 months later, treatment with a dexamethasone implant improved vision to 20/125 OD and 20/150 OS. Conclusion: Among COVID-19-induced AMN, our case is remarkable for the severe progression of visual impairment over 3 months of follow-up and improvement with a dexamethasone implant. Furthermore, absence of classical AMN lesions on fundus photography raises the question whether COVID-induced AMN may lead to a clinically distinct, potentially more severe picture than AMN arising from previously identified causes.

Anatomical and functional outcome of surgical correction of optic disc pit maculopathy using autologous scleral patch graft: a long-term retrospective analysis

BackgroundOptic disc pit (ODP) is a rare congenital anomaly of optic nerve head and is associated with maculopathy. Scleral patch graft (SPG) as a therapeutic option is recently advocated.MethodsThis is a retrospective analysis of 54 patients with ODP maculopathy who were followed up for 12 months post-operatively. The parameters assessed included best corrected visual acuity (BCVA) in LogMAR chart and central macular thickness (CMT) at baseline and at 1-, 3- and 12-months post-surgery.ResultsThe mean age of presentation was 36.36 ± 15.69 years [Median 36, Interquartile range (IQR) 14.75]. 51.85% were female. 53.7% were operated in left eye. The average period of follow-up was 15.37 ± 2.34 months after surgery. The mean presenting BCVA in LogMAR chart was 0.66 ± 0.37 (Median 0.6, IQR 0.4) and average CMT was 677.46 ± 251.57µ (Median 674, IQR 276). On follow up over 1, 3 and 12 months, average BCVA were 0.74, 0.58 and 0.49 LogMAR respectively. The improvement in final BCVA was statistically significant (p = 0.016). The CMT at the corresponding follow-up periods were 461.26 ± 238.3µ (Median 435, IQR 220.5), 362.68 ± 125µ (Median 367, IQR 141) and 287.36 ± 121.9µ (Median 266, IQR 139.5). Decrease in CMT was significant at all follow up visits (p < 0.001). On assessing OCT Biomarkers, Subretinal fluid (57.4%), Intraretinal Fluid (57.4%), macular schitic cavity (79.63%), Outer Lamellar Macular hole (31.48%), Pachychoroid vessels (35.19%), Outer Retinal Layer Disruptions (24.07%) were present in various proportions on presentation. After surgery over the follow-up, retinal fluid and schitic cavities were observed to get regressed over time. Outer Lamellar Macular holes showed excellent regression after surgery over a period of time. On final visit after 1 year of surgery, complete anatomical success in terms of OCT interpretation was achieved in 16 cases (29.63%). Partial anatomical success was achieved in further 24 cases (44.44%). At least some anatomical improvement was seen in 49 patients while in 3 patients it remained almost unaltered and 2 cases worsened. Successful visual rehabilitation was achieved in 45 patients (83.33%)ConclusionsDetailed OCT based and functional analysis in this study with long-term follow-up helps to entitle the importance of scleral patch graft based surgical procedure in managing this challenging surgical condition. This article caters the largest case series with meticulous analyses of the ODP Maculopathy surgically managed using autologous scleral plug.

Photoreceptor assessment in age-related macular degeneration.

Clinical trials investigating drugs for various stages of age-related macular degeneration (AMD) are actively underway and there is a strong interest in outcomes that demonstrate a structure-function-correlation. The ellipsoid zone (EZ), a crucial anatomical feature affected in this disease, has emerged as a strong contender. There is significant interest in evaluating EZ metrics on Optical Coherence Tomography (OCT), such as integrity and reflectivity, as disruption of this photoreceptor-rich layer may indicate disease progression. Loss of photoreceptor integrity in the junctional zone of geographic atrophy (GA) has been shown to exceed the areas of retinal pigment epithelial (RPE) atrophy, thus predicting future GA expansion. Furthermore, reduced visual acuity and retinal sensitivity have been correlated with loss of EZ integrity, underscoring a structure-function relationship. Photoreceptor integrity has also recently been acknowledged by the Food and Drug Administration (FDA), supporting its use as a primary endpoint in clinical trials investigating treatments for GA. However, the segmentation of this EZ still poses challenges. Continuous enhancements in OCT resolution and advancements in automated segmentation algorithms contribute to improved assessment of the EZ, strengthening its potential as an imaging biomarker for assessing photoreceptor function. It remains to be seen whether the EZ will serve as a surrogate marker for intermediate AMD. This article aims to provide an overview of the current understanding and knowledge of the EZ, while addressing ongoing challenges encountered in its assessment and interpretation.

Optimization of Copper Electrodeposition in High Aspect Ratio through Silicon Vias

Copper-filled through silicon vias (TSVs) are a key technology for 3D integration of microelectronic devices. 3D integration enables system miniaturization, increases bandwidth per volume, and improves device performance. In general, TSV copper filling processes are designed to be used with thinned wafers (<200 um), but some TSV last and microelectromechanical systems (MEMS) require full wafer thicknesses, where additional mass of the full wafer is advantageous. For high-power devices, large scale vias or via arrays can be used both to supply power and for thermal management. Copper (Cu) is a preferred material for TSV filling because of its high electrical and thermal conductivity and can be deposited through electrochemical deposition (ECD) to fill high aspect ratio features. Although Cu ECD has been historically performed using three additive systems, recent work has demonstrated that Cu deposition can be achieved in a simplified CuSO4-H2SO4 electrolyte with only a single suppressor additive and halide salt.1,2 The cyclic voltammetry (CV) scan for this electrolyte exhibits s-shaped negative differential resistance (S-NDR), observed as hysteresis in the CV voltage-current relationship between forward and reverse scans. Hysteretic voltammetry indicated bifurcating behavior in the electrolyte system, where bottom-up filling is possible in the vias, while the field surface remains passivated. In systems with limited suppression, performing ECD with a sustained potential leads to localized Cu deposition at specific depths within the vias. An increasingly negative potential waveform can be implemented to progressively move deposition vertically through the vias. Typically, a bottom-up, void-free fill is achieved with this additive-based electrolyte through a potentiostatic plating process with a reference electrode. Voltage-controlled ECD parameters have been developed through the S-NDR mechanism for bottom up filling of high aspect ratio vias, where potential stepping was performed from -500 mV (MSE) to -560 mV (MSE) in -10 mV increments, and each potential was held for 2 to 5 hours to ensure a void-free fill.3 Currently this is a time consuming procedure, with a 17 hour plating process excluding sample preparation.This work shows an optimization method for filling high aspect ratio through silicon vias (TSVs) that provides insights into the fluid replenishment as well as the diffusion and suppression kinetics for this superfilling electroplating chemistry. Both experimental results and computational predictions are shown to better understand the effects of applied plating potentials and the fluid mechanics of this plating process. Understanding the chemical transport of cupric ions and additives is important to both the adsorbed suppression layer formation and disruption within the feature. The S-NDR suppression/fill mechanism is sensitive to the via geometry, ion replenishment, as well as the overpotential during the electroplating process. We demonstrate a time-dependent process window where early on too high of an overpotential results in suppressor breakdown and too low of an overpotential results in complete suppression of the deposition process. Figure 1(a) shows that by controlling the voltage between -520 mV (MSE) and -560 mV (MSE), we were able to demonstrate complete fill of the TSVs in 30% of the time previously required for filling. We also hypothesize that there is a maximum void-free fill rate for suppressor only chemistries. To understand the dependence on solution replenishment and applied bias in a given electrolyte, a series of investigations were performed on samples rotated at different rates as shown in Figure 1(b). This investigation was also shown computationally to optimize void-free, bottom-up plating when changing to different via geometry and array densities. Understanding the filling kinetics and fluid dynamics provides a throughput target for microelectronic devices. Sandia National Laboratories is a multimission laboratory managed and operated by National Technology and Engineering Solutions of Sandia, LLC., a wholly owned subsidiary of Honeywell International, Inc., for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-NA-0003525. SAND (1) Josell, D.; Moffat, T. P. Superconformal Copper Deposition in Through Silicon Vias by Suppression-Breakdown. J. Electrochem. Soc. 2018, 165 (2), D23–D30. https://doi.org/10.1149/2.0061802jes.(2) Menk, L. A.; Josell, D.; Moffat, T. P.; Baca, E.; Blain, M. G.; Smith, A.; Dominguez, J.; McClain, J.; Yeh, P. D.; Hollowell, A. E. Bottom-Up Copper Filling of Large Scale Through Silicon Vias for MEMS Technology. J. Electrochem. Soc. 2019, 166 (1), D3066–D3071. https://doi.org/10.1149/2.0091901jes.(3) Schmitt, R. P.; Menk, L. A.; Baca, E.; Bower, J. E.; Romero, J. A.; Jordan, M. B.; Jackson, N.; Hollowell, A. E. Void-Free Copper Electrodeposition in High Aspect Ratio, Full Wafer Thickness Through-Silicon Vias with Endpoint Detection. J. Electrochem. Soc. 2021, 167 (16), 162517. Figure 1

A molecular view of peptoid-induced acceleration of calcite growth

The extensive deposits of calcium carbonate (CaCO3) generated by marine organisms constitute the largest and oldest carbon dioxide (CO2) reservoir. These organisms utilize macromolecules like peptides and proteins to facilitate the nucleation and growth of carbonate minerals, serving as an effective method for CO2 sequestration. However, the precise mechanisms behind this process remain elusive. In this study, we report the use of sequence-defined peptoids, a class of peptidomimetics, to achieve the accelerated calcite step growth kinetics with the molecular level mechanistic understanding. By designing peptoids with hydrophilic and hydrophobic blocks, we systematically investigated the acceleration in step growth rate of calcite crystals using in situ atomic force microscopy (AFM), varying peptoid sequences and concentrations, CaCO3 supersaturations, and the ratio of Ca2+/ HCO3-. Mechanistic studies using NMR, three-dimensional fast force mapping (3D FFM), and isothermal titration calorimetry (ITC) were conducted to reveal the interactions of peptoids with Ca2+ and HCO3- ions in solution, as well as the effect of peptoids on solvation and energetics of calcite crystal surface. Our results indicate the multiple roles of peptoid in facilitating HCO3- deprotonation, Ca2+ desolvation, and the disruption of interfacial hydration layers of the calcite surface, which collectively contribute to a peptoid-induced acceleration of calcite growth. These findings provide guidelines for future design of sequence-specific biomimetic polymers as crystallization promoters, offering potential applications in environmental remediation (such as CO2 sequestration), biomedical engineering, and energy storage where fast crystallization is preferred.

Porphyromonas gingivalis GroEL accelerates abdominal aortic aneurysm formation by matrix metalloproteinase-2 SUMOylation in vascular smooth muscle cells: A novel finding for the activation of MMP-2.

Infection is a known cause of abdominal aortic aneurysm (AAA), and matrix metalloproteases-2 (MMP-2) secreted by vascular smooth muscle cells (SMCs) plays a key role in the structural disruption of the middle layer of the arteries during AAA progression. The periodontal pathogen Porphyromonas gingivalis is highly associated with the progression of periodontitis. GroEL protein of periodontal pathogens is an important virulence factor that can invade the body through either the bloodstream or digestive tract and is associated with numerous systemic diseases. Although P. gingivalis aggravates AAA by increasing the expression of MMP-2 in animal studies, the molecular mechanism through which P. gingivalis regulates the expression of MMP-2 is still unknown and requires further investigation. In this study, we first confirmed through animal experiments that P. gingivalis GroEL promotes MMP-2 secretion from vascular SMCs, thereby aggravating Ang II-induced aortic remodeling and AAA formation. In addition, rat vascular SMCs and A7r5 cells were used to investigate the underlying mechanisms in vitro. The results demonstrated that GroEL can promote the interaction between the K639 site of MMP-2 and SUMO-1, leading to MMP-2 SUMOylation, which inhibits the reoccurrence of non-K639-mediated monoubiquitylation. Hence, the monoubiquitylation-mediated lysosomal degradation of MMP-2 is inhibited, consequently promoting MMP-2 stability and production. SUMOylation may facilitate intra-endoplasmic reticulum (ER) and Golgi trafficking of MMP-2, thereby enhancing its transport capacity. In conclusion, this is the first report demonstrating the presence of a novel posttranslational modification, SUMOylation, in the MMP family, suggesting that P. gingivalis GroEL may exacerbate AAA formation by increasing MMP-2 production through SUMOylation in vascular SMCs. This study also provides a novel perspective on the role of SUMOylation in MMP-2-induced systemic diseases.

Flow and heat transfer characteristics of low water content jet fuel in U-bend tubes: A numerical study using LES and DPM approaches

This study provides an in-depth analysis of the flow and heat transfer behavior of low-water-content jet fuel (α ≤ 2 %) in U-bend tubes, utilizing Large Eddy Simulations (LES) and Discrete Phase Models (DPM). The research focus on the influence of radii of curvature ratio (r/D), flow rates (Qtp) and α on flow dynamics and heat transfer mechanisms. Flow fields for r/D = 1 and r/D ≥ 2.5, where distinct secondary flow structures, play a critical role in shaping internal flow behavior. These vortices significantly enhance flow mixing and heat transfer, especially on the inner wall, through complex multi-level vortex interactions. The local wall Nusselt number shows a close correlation with vorticity trends, initially increasing and then decreasing, with notable deviations near the inlet and outlet regions. This non-uniform heat transfer is primarily driven by the interaction of secondary flow structures and adverse pressure gradients near the inner wall, while higher Qtp and smaller r/D can improve heat transfer uniformity under certain flow conditions. The presence of droplets increases the total wall Nusselt number by 4 % to 60 % compared to single-phase jet fuel flow, due to two-phase interaction and boundary layer disruption. Finally, the study proposes modified correlations for pressure drop gradients and total wall Nusselt numbers, accounting for effects of r/D and multiphase heat transfer processes. These correlations, validated with RRMSEs of 3.54 % and 6.80 % respectively, provide valuable insights for improving heat transfer efficiency in fuel systems and form a theoretical foundation for real-time monitoring technologies in aircraft fuel lines.

Azimuthally-distributed wavy inner wall treatment for high subsonic jet noise control

The noise generated by subsonic jet nozzles, commonly encountered in civilian aircraft, is rather significant and propagates in both the upstream and downstream directions due to large-scale and fine-scale turbulence structures. In this paper, a distinctive inner wall treatment strategy, denoted as the Azimuthally-distributed Wavy Inner Wall (AWIW), is proposed, which is aimed at mitigating jet noise. Within this strategy, a circumferentially dispersed treatment wall characterized by a minute wavy pattern is substituted for the smooth inner wall in proximity to the nozzle outlet. To assess the effectiveness of the AWIW treatment, we conducted numerical simulations. The unsteady flow field and far-field noise were predicted by employing Large Eddy Simulations (LES) coupled with the Ffowcs Williams and Hawkings (FW-H) integration method. To gain a comprehensive understanding of the mechanism underlying the noise reduction facilitated by the AWIW treatment, it examined physical parameters such as the Lighthill source acoustic source term, the turbulent kinetic energy acoustic source term, and the shear layer instability. The results reveal that the AWIW treatment expedites the instability within the shear layer of the jet, leading to an early disruption of the jet shear layer, and consequently turbulent structures in varying sizes are generated downstream. This process effectively regulates the generation and emission of jet noise. By controlling the minor scale turbulence through the AWIW treatment, the mid- and high-frequency noise within the distant field can be significantly reduced. In the context of the flow field, the introduction of AWIW also leads to a decrease in drag on the inner wall surface of the jet, thereby improving the overall aerodynamic performance of the nozzle. Considering these attributes, the AWIW strategy emerges as a viable technique for the reduction of jet noise.

Predictive Factors for Functional and Anatomical Outcomes After Anti-VEGF Treatment for Macular Edema in Patients with Branch Retinal Vein Occlusion.

This study aimed to identify predictive factors for the improvement of best-corrected visual acuity (BCVA) and reduction of central macular thickness (CMT) after treatment of macular edema (ME) due to branch retinal vein occlusion (BRVO) in a real-world setting. This retrospective study included patients with ME secondary to BRVO who were treated with intravitreal injection of bevacizumab as the first-line therapy and were followed up for 12 months. Demographic and clinical data, in addition to baseline spectral domain optical coherence tomography (SD-OCT) features, were considered as possible biomarkers of final BCVA and CMT. We also collected the data concerning the need for additional treatment including sectorial laser photocoagulation, change to another anti-VEGF agent, or intravitreal corticosteroid injection. A total of 161 eyes were analyzed. BCVA significantly improved from baseline to 12-month follow-up (0.6 and 0.4 logMAR, respectively; P 0.01). CMT decreased significantly during the follow-up period (from 498.0 to 325.0 m; P 0.01). Final BCVA correlated positively with baseline BCVA (P 0.01, r = 0.57). Older age at diagnosis and baseline SD-OCT findings including CMT, disruption of the retinal inner layers, retinal pigment epithelium (RPE) damage, and impairment of the ellipsoid zone and external limiting membrane negatively affected final BCVA (P 0.01). Multiple regression analysis identified age and BCVA at baseline as the only independent predictors of final BCVA (P = 0.001 and P 0.01, respectively). No association was found between clinical data, SD-OCT parameters, and final CMT. Various clinical and SD-OCT parameters are prognostically relevant for visual improvement in ME secondary to BRVO. Age at diagnosis and baseline BCVA were found to be independent predictors of visual outcome.

The ApoA1-mimetic peptide 4F blocks flavivirus NS1-triggered endothelial dysfunction and protects against lethal dengue virus challenge

Flavivirus infections result in a variety of outcomes, from clinically inapparent infections to severe, sometimes fatal cases characterized by hemorrhagic manifestations and vascular leakage leading to shock (dengue), meningomyeloencephalitis (West Nile), and congenital abnormalities (Zika). Although there are approved vaccines against several flaviviruses, potentially enhancing cross-reactive immune responses have complicated the development and implementation of vaccines against dengue and Zika viruses, and no specific therapeutics currently exist. The flavivirus nonstructural protein 1 (NS1) is a promising antiviral target because it is a conserved multifunctional virulence factor that directly triggers vascular leak. We previously showed that interactions between NS1 and the ApoA1 lipoprotein modulate DENV infection. Here, we evaluated the potential of the ApoA1-mimetic peptide, 4F, to interfere with endothelial dysfunction mediated by the NS1 protein of dengue, Zika, and West Nile flaviviruses. In an in vitro model consisting of human endothelial cell monolayers, 4F inhibited NS1-induced hyperpermeability, as measured by a transendothelial electrical resistance assay, and prevented NS1-triggered disruption of the endothelial glycocalyx layer. We also demonstrate that treatment with 4F inhibited NS1 interaction with endothelial cells. Finally, we show that 4F protects against lethal DENV challenge in a mouse model, reducing morbidity and mortality in a dose-dependent manner. Our data demonstrate the potential of 4F to inhibit flavivirus NS1-mediated pathology and severe dengue disease in mice and suggest that 4F can also serve as a molecular tool to probe different NS1 functions in vitro and in vivo.

Orally Ingested Micro- and Nano-Plastics: A Hidden Driver of Inflammatory Bowel Disease and Colorectal Cancer.

Micro- and nano-plastics (MNPLs) can move along the food chain to higher-level organisms including humans. Three significant routes for MNPLs have been reported: ingestion, inhalation, and dermal contact. Accumulating evidence supports the intestinal toxicity of ingested MNPLs and their role as drivers for increased incidence of colorectal cancer (CRC) in high-risk populations such as inflammatory bowel disease (IBD) patients. However, the mechanisms are largely unknown. In this review, by using the leading scientific publication databases (Web of Science, Google Scholar, Scopus, PubMed, and ScienceDirect), we explored the possible effects and related mechanisms of MNPL exposure on the gut epithelium in healthy conditions and IBD patients. The summarized evidence supports the idea that oral MNPL exposure may contribute to intestinal epithelial damage, thus promoting and sustaining the chronic development of intestinal inflammation, mainly in high-risk populations such as IBD patients. Colonic mucus layer disruption may further facilitate MNPL passage into the bloodstream, thus contributing to the toxic effects of MNPLs on different organ systems and platelet activation, which may, in turn, contribute to the chronic development of inflammation and CRC development. Further exploration of this threat to human health is warranted to reduce potential adverse effects and CRC risk.

Solid-liquid interfacial nanobubble nucleation dynamics influenced by surface hydrophobicity and gas oversaturation

Over the past two decades, extensive research efforts have been devoted to exploring the existence, stability, and applications of interfacial nanobubbles (INBs). However, investigations into the microscopic nucleation process of INBs have been relatively limited. In this study, we utilized molecular dynamics simulations to elucidate the nucleation dynamics of INBs, with a particular focus on examining the influence of surface hydrophobicity and gas oversaturation. Our findings revealed a distinct preference for INBs to form on hydrophobic surfaces compared to hydrophilic ones, which agrees well with the experimental results. Temporal evolution analysis of the interfacial density of gas and liquid near the solid–liquid interface indicated a gradual enrichment of gas molecules at the hydrophobic surface, accompanied by a gradual disruption of the hydration layer, phenomena not observed on hydrophilic surfaces. The affinity of gas molecules towards the hydrophobic surface was further confirmed by potential of mean force (PMF) analysis, which demonstrated a decrease in the energy barrier and an increase in the potential well with increasing surface hydrophobicity. Moreover, increasing bulk gas supersaturation and surface hydrophobicity both contribute to shortening the INB nucleation time, primarily due to the enhanced gas enrichment rate. Further studies indicated that the gas enrichment rate had a directly proportional linear relationship with the bulk gas concentration. However, as the surface hydrophobicity increased, the gas enrichment rate initially rose rapidly and then entered a plateau phase. This may be because, when surface hydrophobicity is strong, the gas enrichment rate becomes limited by the diffusion of gas molecules in the liquid. These findings offer valuable insights into the nucleation mechanism of INBs on hydrophobic surfaces under gas oversaturation, contributing to a deeper understanding of their behavior and potential applications.

Sodium-iodate injection can replicate retinal and choroid degeneration in pigmented mice: Using multimodal imaging and label-free quantitative proteomics analysis

Age-related macular degeneration (AMD) is the leading cause of irreversible visual loss in the elderly population. Sodium iodate (NaIO3), a stable oxidizing agent, has been injected to establish a reproducible model of oxidative stress-induced RPE and photoreceptor death. The aim of our study was to evaluate the morphological and molecular changes of retina and retinal pigment epithelium (RPE)-choroid in NaIO3-treated mouse using multimodal fundus imaging and label-free quantitative proteomics analysis. Here, we found that following NaIO3 injection, retinal degeneration was evident. Fundus photographs showed numerous scattered yellow-white speckled deposits. Optical coherence tomography (OCT) images indicated disruption of the retinal layers, damage of the RPE layer and accumulation of hyper-reflective matter in multiple layers of the outer retina. Widespread foci of a high fundus autofluorescence (FAF) signal were noticed. Fundus fluorescein angiography (FFA) revealed diffuse intense transmitted fluorescence mixed with scattered spot-like blocked fluorescence. Indocyanine green angiography (ICGA) presented punctate hyperfluorescence. Due to the atrophy of the RPE and Bruch's membrane and choroidal capillary complex, the larger choroidal vessels become more prominent in ICGA and optical coherence tomography angiography (OCTA). Transmission electron microscope (TEM) illustrated abnormal material accumulation and damaged mitochondria. Bioinformatics analysis of proteomics revealed that the differentially expressed proteins participated in diverse biological processes, encompassing phototransduction, NOD-like receptor signaling pathway, phagosome, necroptosis, and cell adhesion molecules. In conclusion, by multimodal imaging, we described the phenotype of NaIO3-treated mouse model mimicking oxidative stress-induced RPE and photoreceptor death in detail. In addition, proteomics analysis identified differentially expressed proteins and significant enrichment pathways, providing insights for future research, although the exact mechanism of oxidative stress-induced RPE and photoreceptor death remains incompletely understood.

Yangyin Huowei mixture alleviates chronic atrophic gastritis by inhibiting the IL-10/JAK1/STAT3 pathway.

The Chinese medicine Yangyin Huowei mixture (YYHWM) exhibits good clinical efficacy in the treatment of chronic atrophic gastritis (CAG), but the mechanisms underlying its activity remain unclear. To investigate the therapeutic effects of YYHWM and its underlying mechanisms in a CAG rat model. Sprague-Dawley rats were allocated into control, model, vitacoenzyme, and low, medium, and high-dose YYHWM groups. CAG was induced in rats using N-methyl-N'-nitro-N-nitrosoguanidine, ranitidine hydrochloride, hunger and satiety perturbation, and ethanol gavage. Following an 8-wk intervention period, stomach samples were taken, stained, and examined for histopathological changes. ELISA was utilized to quantify serum levels of PG-I, PG-II, G-17, IL-1β, IL-6, and TNF-α. Western blot analysis was performed to evaluate protein expression of IL-10, JAK1, and STAT3. The model group showed gastric mucosal layer disruption and inflammatory cell infiltration. Compared with the blank control group, serum levels of PGI, PGII, and G-17 in the model group were significantly reduced (82.41 ± 3.53 vs 38.52 ± 1.71, 23.06 ± 0.96 vs 11.06 ± 0.70, and 493.09 ± 12.17 vs 225.52 ± 17.44, P < 0.01 for all), whereas those of IL-1β, IL-6, and TNF-α were significantly increased (30.15 ± 3.07 vs 80.98 ± 4.47, 69.05 ± 12.72 vs 110.85 ± 6.68, and 209.24 ± 11.62 vs 313.37 ± 36.77, P < 0.01 for all), and the protein levels of IL-10, JAK1, and STAT3 were higher in gastric mucosal tissues (0.47 ± 0.10 vs 1.11 ± 0.09, 0.49 ± 0.05 vs 0.99 ± 0.07, and 0.24 ± 0.05 vs 1.04 ± 0.14, P < 0.01 for all). Compared with the model group, high-dose YYHWM treatment significantly improved the gastric mucosal tissue damage, increased the levels of PGI, PGII, and G-17 (38.52 ± 1.71 vs 50.41 ± 3.53, 11.06 ± 0.70 vs 15.33 ± 1.24, and 225.52 ± 17.44 vs 329.22 ± 29.11, P < 0.01 for all), decreased the levels of IL-1β, IL-6, and TNF-α (80.98 ± 4.47 vs 61.56 ± 4.02, 110.85 ± 6.68 vs 89.20 ± 8.48, and 313.37 ± 36.77 vs 267.30 ± 9.31, P < 0.01 for all), and evidently decreased the protein levels of IL-10 and STAT3 in gastric mucosal tissues (1.11 ± 0.09 vs 0.19 ± 0.07 and 1.04 ± 0.14 vs 0.55 ± 0.09, P < 0.01 for both). YYHWM reduces the release of inflammatory factors by inhibiting the IL-10/JAK1/STAT3 pathway, alleviating gastric mucosal damage, and enhancing gastric secretory function, thereby ameliorating CAG development and cancer transformation.

Variable Area Jet Impingement for Enhanced Junction Temperature Control of High-Power Electronics

Abstract Convective heat transfer by jet impingement cooling offers a suitable solution for high heat flux applications. Compared to techniques that rely on bulk conduction in series with convection, direct liquid impingement reduces the thermal resistance between power device hot spots and the coolant. Although capable of highly efficient cooling, static impingement devices must be designed for the worst-case cooling requirements for a transient power profile. This can result in wasted hydraulic performance. Aircraft, highway vehicles, and heavy machinery fall into this category where a substantial factor of safety is required. This work proposes a method for improving power electronics reliability by limiting temperature fluctuations at reduced coolant pressure requirements during transient power cycling using a variable area jet. Single phase jet impingement cooling is implemented in an active control scheme using a variable diameter iris mechanism as the primary nozzle architecture. In addition to pressure drop and temperature control, the active nozzle structure introduces the ability to create pulsating jet flows to further enhance the heat transfer compared to fixed-geometry nozzles. The key underlying fluid mechanics characteristic of pulsating flows is the effect of disrupting the thermal boundary layer on the electrical device surface. By introducing a variable diameter jet, eddy formation can be fine-tuned for optimal boundary layer disruption. Using the definition of the Strouhal number, vortex shedding created by the non-steady jet flows is directly correlated with the resulting Nusselt number as a function of the iris kinematics. An experimental apparatus for jet impingement thermal-fluid testing is used to evaluate the Nusselt number versus Strouhal number for a parametric study of variable diameter iris configurations. The apparatus utilizes a voice coil actuator to achieve sine and square waveforms, to vary the amplitude of actuation, and to vary the mean of actuation. Finally, power cycling with a single emulated hot spot is performed to estimate the reliability increase as a result of maintaining constant junction temperatures with the active jet impingement scheme.

Experimental investigation of porous gyroid structure: Effect of cell size and porosity on performance

This paper presents an experimental investigation of three triply periodic minimal surface based gyroid sheet samples with varying cell size and porosity. The thermal and hydraulic performances of the samples were analyzed and compared under different design parameters (cell size and porosity). The experimental results revealed that the gyroid structures achieved uniform temperature distribution, allowing for the disruption of the thermal boundary layer and enhancing heat transfer. The gyroid structure characterised by small cell size and low porosity (Gyroid-A: 15 mm/0.75) dissipates more heat from its surface compared to the structure with large cell size and high porosity (Gyroid-C: 32 mm/0.9). Gyroid-A also exhibits higher Nusselt number and convection heat transfer coefficient with 51.5 % increase as compared to Gyroid-C. In addition, Gyroid-A has the lowest thermal resistance (with maximum of 45.4 % reduction) and the highest specific pressure drop as compared to the other gyroid structures. Moreover, Gyroid-A exhibits lower total entropy generation (75.9 % reduction) and higher overall performance evaluation criteria, PEC (more efficient heat transfer in relation to flow resistance) as compared to Gyroid-C. The experimental results of this work is important for the design and optimization of heat transfer applications utilizing gyroid sheet structures for effective heat dissipation.

Torpedo maculopathy

Abstract Torpedo maculopathy is a rare congenital defect of the retinal pigment epithelium that produces a disruption of outer retinal layers. It is a hypopigmented torpedo-shaped lesion temporal to the macula, pointing toward the fovea. The visual acuity is usually normal because there is no foveal involvement. Regular follow-up is required in these patients as they can develop choroidal neovascularization.

Nuclear receptor signaling via NHR-49/MDT-15 regulates stress resilience and proteostasis in response to reproductive and metabolic cues.

The ability to sense and respond to proteotoxic insults declines with age, leaving cells vulnerable to chronic and acute stressors. Reproductive cues modulate this decline in cellular proteostasis to influence organismal stress resilience in Caenorhabditis elegans We previously uncovered a pathway that links the integrity of developing embryos to somatic health in reproductive adults. Here, we show that the nuclear receptor NHR-49, an ortholog of mammalian peroxisome proliferator-activated receptor α (PPARα), regulates stress resilience and proteostasis downstream from embryo integrity and other pathways that influence lipid homeostasis and upstream of HSF-1. Disruption of the vitelline layer of the embryo envelope, which activates a proteostasis-enhancing intertissue pathway in somatic cells, triggers changes in lipid catabolism gene expression that are accompanied by an increase in fat stores. NHR-49, together with its coactivator, MDT-15, contributes to this remodeling of lipid metabolism and is also important for the elevated stress resilience mediated by inhibition of the embryonic vitelline layer. Our findings indicate that NHR-49 also contributes to stress resilience in other pathways known to change lipid homeostasis, including reduced insulin-like signaling and fasting, and that increased NHR-49 activity is sufficient to improve proteostasis and stress resilience in an HSF-1-dependent manner. Together, our results establish NHR-49 as a key regulator that links lipid homeostasis and cellular resilience to proteotoxic stress.