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The pulmonary artery-to-left atrium (LA) fistula is one of the rare and unique structural causes of silent cyanosis. This correctable abnormality can be identified by having a high index of clinical suspicion and appropriate investigations using echocardiography and cardiac computed tomography (CT). We report an eight-year-old child who had worsening exertional dyspnea, long-standing central cyanosis, and recurrent infections. A large-sized fistula connecting the right pulmonary artery (RPA) to the LA with all the right- and left-sided pulmonary veins showed normal drainage into the LA, suggesting a type I RPA-to-LA fistula, which was diagnosed on cardiac CT. Percutaneous closure using the occluder device is planned as further management for the patient.
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Intracellular redox homeostasis in the airway epithelium is closely regulated through adaptive signaling and metabolic pathways. However, inhalational exposure to xenobiotic stressors such as secondary organic aerosols (SOA) can alter intracellular redox homeostasis. Isoprene hydroxy hydroperoxide (ISOPOOH), a ubiquitous volatile organic compound derived from the atmospheric photooxidation of biogenic isoprene, is a major contributor to SOA. We have previously demonstrated that exposure of human airway epithelial cells (HAEC) to ISOPOOH induces oxidative stress through multiple mechanisms including lipid peroxidation, glutathione oxidation, and alterations of glycolytic metabolism. Using dimedone-based reagents and copper catalyzed azo-alkynyl cycloaddition to tag intracellular protein thiol oxidation, we demonstrate that exposure of HAEC to micromolar levels of ISOPOOH induces reversible oxidation of cysteinyl thiols in multiple intracellular proteins, including GAPDH, that was accompanied by a dose-dependent loss of GAPDH enzymatic activity. These results demonstrate that ISOPOOH induces an oxidative modification of intracellular proteins that results in loss of GAPDH activity, which ultimately impacts the dynamic regulation of the intracellular redox homeostatic landscape in HAEC.
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Células Epiteliales , Oxidación-Reducción , Estrés Oxidativo , Compuestos de Sulfhidrilo , Humanos , Células Epiteliales/metabolismo , Células Epiteliales/efectos de los fármacos , Compuestos de Sulfhidrilo/metabolismo , Estrés Oxidativo/efectos de los fármacos , Gliceraldehído-3-Fosfato Deshidrogenasas/metabolismo , Hemiterpenos/metabolismo , Peróxidos/metabolismoRESUMEN
Inhalation exposure to plastic incineration emissions (PIEs) is a problem of increasing human relevance, as plastic production and waste creation have drastically increased since mainstream integration during the 20th century. We investigated the effects of PIEs on human nasal epithelial cells (HNECs) to understand if such exposures cause damage and dysfunction to respiratory epithelia. Primary HNECs from male and female donors were cultured at air-liquid interface (ALI), and 16HBE cells were cultured on coverslips. Smoke condensates were generated from incineration of plastic at flaming (640°C) and smoldering (500°C) temperatures, and cells were subsequently exposed to these materials at 5-50 µg/cm2 concentrations. HNECs were assessed for mitochondrial dysfunction and 16HBE cells for glutathione oxidation in real-time analyses. HNEC culture supernatants and total RNA were collected at 4-h postexposure for cytokine and gene expression analysis, and results show that PIEs can acutely induce inflammation, oxidative stress, and mitochondrial dysfunction in HNECs, and that incineration temperature modifies biological responses. Specifically, condensates from flaming and smoldering PIEs significantly increased HNEC secretion of cytokines IL-8, IL-1ß, and IL-13, as well as expression of xenobiotic metabolism pathways and genes such as CYP1A1 and CYP1B1 at 5 and 20 µg/cm2 concentrations. Only 50 µg/cm2 flaming PIEs significantly increased glutathione oxidation in 16HBEs, and decreased respiration and ATP production in HNEC mitochondria. Impact Statement: Our data reveal the impact of incineration temperatures on biological outcomes associated with PIE exposures, emphasizing the importance of temperature as a factor when evaluating respiratory disease associated with PIEs exposure.
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Contaminantes Atmosféricos , Células Epiteliales , Incineración , Inflamación , Estrés Oxidativo , Humanos , Estrés Oxidativo/efectos de los fármacos , Femenino , Masculino , Células Epiteliales/efectos de los fármacos , Células Epiteliales/metabolismo , Contaminantes Atmosféricos/toxicidad , Inflamación/inducido químicamente , Inflamación/metabolismo , Plásticos/toxicidad , Metabolismo Energético/efectos de los fármacos , Células Cultivadas , Citocinas/metabolismo , Mitocondrias/efectos de los fármacos , Mitocondrias/metabolismo , Mucosa Respiratoria/efectos de los fármacos , Mucosa Respiratoria/metabolismo , Glutatión/metabolismo , Humo/efectos adversos , Citocromo P-450 CYP1B1/genética , Citocromo P-450 CYP1B1/metabolismo , Citocromo P-450 CYP1A1/genética , Citocromo P-450 CYP1A1/metabolismo , Exposición por Inhalación/efectos adversosRESUMEN
Wildland fires contribute significantly to the ambient air pollution burden worldwide, causing a range of adverse health effects in exposed populations. The toxicity of woodsmoke, a complex mixture of gases, volatile organic compounds, and particulate matter, is commonly studied in vitro using isolated exposures of conventionally cultured lung cells to either resuspended particulate matter or organic solvent extracts of smoke, leading to incomplete toxicity evaluations. This study aimed to improve our understanding of the effects of woodsmoke inhalation by building an advanced in vitro exposure system that emulates human exposure of the airway epithelium. We report the development and characterization of an innovative system that permits live-cell monitoring of the intracellular redox status of differentiated primary human bronchial epithelial cells cultured at an air-liquid interface (pHBEC-ALI) as they are exposed to unfractionated woodsmoke generated in a tube furnace in real time. pHBEC-ALI exposed to freshly generated woodsmoke showed oxidative changes that were dose-dependent and reversible, and not attributable to carbon monoxide exposure. These findings show the utility of this novel system for studying the molecular initiating events underlying woodsmoke-induced toxicity in a physiologically relevant in vitro model, and its potential to provide biological plausibility for risk assessment and public health measures.
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Contaminación del Aire , Material Particulado , Humanos , Material Particulado/toxicidad , Humo/efectos adversos , Pulmón , Células EpitelialesRESUMEN
Monitoring object displacement is critical for structural health monitoring (SHM). Radio frequency identification (RFID) sensors can be used for this purpose. Using more sensors enhances displacement estimation accuracy, especially when it is realized through the use of machine learning (ML) algorithms for predicting the direction of arrival of the associated signals. Our research shows that ML algorithms, in conjunction with adequate RFID passive sensor data, can precisely evaluate azimuth angles. However, increasing the number of sensors can lead to gaps in the data, which typical numerical methods such as interpolation and imputation may not fully resolve. To overcome this challenge, we propose enhancing the sensitivity of 3D-printed passive RFID sensor arrays using a novel photoluminescence-based RF signal enhancement technique. This can boost received RF signal levels by 2 dB to 8 dB, depending on the propagation mode (near-field or far-field). Hence, it effectively mitigates the issue of missing data without necessitating changes in transmit power levels or the number of sensors. This approach, which enables remote shaping of radiation patterns via light, can herald new prospects in the development of smart antennas for various applications apart from SHM, such as biomedicine and aerospace.
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In this study, we compared 12 mm cell culture inserts with permeable polyester membranes (0.4 µm pores) from two different manufacturers: CELLTREAT® and Corning®. Physical dimensions and masses of the inserts were found to be very similar between the two brands, with CELLTREAT® inserts having a slightly smaller diameter and growth area (11.91 mm; 1.11 cm2 ) compared to Corning® Transwells® (12 mm; 1.13 cm2 ). We compared cell differentiation outcomes of human nasal epithelial cells (HNECs) at air-liquid interface grown on inserts from the two different manufacturers, including trans-epithelial electrical resistance, ciliary beat frequency, ciliated area, and gene expression. HNECs from three male donors were used for all endpoints. No statistically significant differences were observed between paired cultures grown on different brands of insert. In conclusion, these inserts are comparable for use with airway epithelial cell model systems and likely do not impact cellular differentiation or cell culture quality.
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Técnicas de Cultivo de Célula , Células Epiteliales , Humanos , Masculino , Técnicas de Cultivo de Célula/métodos , Células Epiteliales/metabolismo , Sistema Respiratorio , Células Cultivadas , Diferenciación CelularRESUMEN
Exposure to ozone (O3) is associated with adverse respiratory and cardiovascular outcomes. Alterations in circulating microRNAs (miRNAs) may contribute to the adverse vascular effects of O3 exposure through inter-cellular communication resulting in post-transcriptional regulation of messenger RNAs by miRNAs. In this study, we investigated whether O3 exposure induces alterations in circulating miRNAs that can mediate effects on downstream vascular and coagulation biomarkers. Twenty-three healthy male adults were exposed on successive days to filtered air and 300 ppb O3 for 2 h. Circulating miRNA and protein biomarkers were quantified after each exposure session. The data were subjected to mixed-effects model and mediation analyses for the statistical analyses. The results showed that the expression level of multiple circulating miRNAs (e.g., miR-19a-3p, miR-34a-5p) was significantly associated with O3 exposure. Pathway analysis showed that these miRNAs were predictive of changing levels of downstream biomarkers [e.g., D-dimer, C-reactive protein, tumor necrosis factor α (TNFα)]. Mediation analysis showed that miR-19a-3p may be a significant mediator of O3-exposure-induced changes in blood TNFα levels [0.08 (0.01, 0.15), p = 0.02]. In conclusion, this preliminary study showed that O3 exposure of healthy male adults resulted in changes in circulating miRNAs, some of which may mediate vascular effects of O3 exposure.
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While redox processes play a vital role in maintaining intracellular homeostasis by regulating critical signaling and metabolic pathways, supra-physiological or sustained oxidative stress can lead to adverse responses or cytotoxicity. Inhalation of ambient air pollutants such as particulate matter and secondary organic aerosols (SOA) induces oxidative stress in the respiratory tract through mechanisms that remain poorly understood. We investigated the effect of isoprene hydroxy hydroperoxide (ISOPOOH), an atmospheric oxidation product of vegetation-derived isoprene and a constituent of SOA, on intracellular redox homeostasis in cultured human airway epithelial cells (HAEC). We used high-resolution live cell imaging of HAEC expressing the genetically encoded ratiometric biosensors Grx1-roGFP2, iNAP1, or HyPer, to assess changes in the cytoplasmic ratio of oxidized glutathione to reduced glutathione (GSSG:GSH), and the flux of NADPH and H2O2, respectively. Non-cytotoxic exposure to ISOPOOH resulted in a dose-dependent increase of GSSG:GSH in HAEC that was markedly potentiated by prior glucose deprivation. ISOPOOH-induced increase in glutathione oxidation were accompanied by concomitant decreases in intracellular NADPH. Following ISOPOOH exposure, the introduction of glucose resulted in a rapid restoration of GSH and NADPH, while the glucose analog 2-deoxyglucose resulted in inefficient restoration of baseline GSH and NADPH. To elucidate bioenergetic adaptations involved in combatting ISOPOOH-induced oxidative stress we investigated the regulatory role of glucose-6-phosphate dehydrogenase (G6PD). A knockout of G6PD markedly impaired glucose-mediated recovery of GSSG:GSH but not NADPH. These findings reveal rapid redox adaptations involved in the cellular response to ISOPOOH and provide a live view of the dynamic regulation of redox homeostasis in human airway cells as they are exposed to environmental oxidants.
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Glutatión , Peróxido de Hidrógeno , Humanos , Peróxido de Hidrógeno/farmacología , Disulfuro de Glutatión/metabolismo , Oxidación-Reducción , Glutatión/metabolismo , Células Epiteliales/metabolismo , Estrés Oxidativo , Sistema Respiratorio/metabolismo , Glucosa/farmacología , NADP/metabolismoRESUMEN
Economic interventions have social consequences. In this paper, we explore one such relationship, between microfinance intensity and social distrust levels reported by the low-income people. We find a significant association between microfinance intensity in a country and distrust among the poor as well as ultra-poor in cross-section using World Values Survey & European Values Survey (WVS-EVS) Wave 7 (2017-2022). We supplement these findings using empirical Bayes on a panel extending back from 7th to the 4th WVS wave (1999-2004). To deal with potential endogeneity, we run 2SLS as well as weak instruments-robust conditional instrumental variable tests and find evidence showing microfinance prevalence intensity affects distrust levels among the poor and ultra-poor households. We find no association between microfinance and distrust levels in the rich in any of the tests, potentially because the rich are not exposed to microfinance.
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Composición Familiar , Pobreza , Humanos , Teorema de Bayes , PrevalenciaRESUMEN
In this study, a eutectic gallium-indium (EGaIn) alloy and graphene nanoplatelets (GnPs) were employed as reinforcements for a comonomer vinyl ester (cVE) resin at different weight fractions up to 2% via a direct polymerization process. First, the effect of EGaIn on the curing kinetics of cVE was evaluated. The thermal and mechanical properties, and the fracture toughness of two types of cVE composites consisting of EGaIn and GnPs were then studied. The results showed that sub-micron sized EGaIn (≤1 wt.%) could promote the curing reaction of cVE without changing the curing mechanism. However, with further increases in EGaIn loading between 1 and 2 wt.%, the curing reaction rate tends to decrease. Both EGaIn and GnPs showed a significant enhancement in strengthening and toughening the cVE matrix with the presence of filler loading up to 1 wt.%. EGaIn was more effective than GnPs in promoting the flexural and impact strength. An increase of up to 50% and 32% were recorded for these mechanical properties, when EGaln was used, as compared to 46%, and 18% for GnPs, respectively. In contrast, the GnPs/cVE composites exhibited a greater improvement in the fracture toughness and fracture energy by up to 50% and 56% in comparison with those of the EGaIn/cVE ones by up to 32% and 39%, respectively. Furthermore, the stiffness of both the EgaIn/cVE and GnPs/cVE composites showed a significant improvement with an increase of up to 1.76 and 1.83 times in the normalized storage modulus, respectively, while the glass transition temperature (Tg) values remained relatively constant. This work highlights the potential of EGaIn being employed as a filler in creating high-performance thermoset composites, which facilitates its widening applications in many structural and engineering fields, where both higher toughness and stiffness are required.
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Radio frequency identification (RFID) tags are small, low-cost, wearable, and wireless sensors that can detect movement in structures, humans, or robots. In this paper, we use passive RFID tags for structural health monitoring by detecting displacements. We employ a novel process of using 3D printable embedded passive RFID tags within uniform linear arrays together with the multiple signal classification algorithm to estimate the direction of arrival using only the phase of the backscattered signals. We validate our proposed approach via data collected from real-world experiments using a unipolar RFID reader antenna and both narrowband and wideband measurements.
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Dispositivo de Identificación por Radiofrecuencia , Humanos , Algoritmos , Impresión TridimensionalRESUMEN
Regenerative biomaterials play a crucial role in the success of maxillofacial reconstructive procedures. Yet today, limited options are available when choosing polymeric biomaterials to treat critical size bony defects. Further, there is a requirement for 3D printable regenerative biomaterials to fabricate customized structures confined to the defect site. We present here a 3D printable composite formulation consisting of polycaprolactone (PCL) and silk fibroin microfibers and have established a robust protocol for fabricating customized 3D structures of complex geometry with the composite. The 3D printed composite scaffolds demonstrated higher compressive modulus than 3D printed scaffolds of PCL alone. Furthermore, the compressive modulus of PCL-Antheraea mylitta (AM) silk scaffolds is higher than that of the PCL-Bombyx mori (BM) silk scaffolds at their respective ratios. Compressive modulus of PCL-25AM silk scaffolds (73.4 MPa) is higher than that of PCL-25BM silk scaffolds (65.1 MPa). Compressive modulus of PCL-40AM silk scaffolds (106.1 MPa) is higher than that of PCL-40BM silk scaffolds (77.7 MPa). Moreover, we have isolated, characterized, and integrated human gingival mesenchymal stem cells (hGMSCs), an effective autologous cell source, onto the 3D printed scaffolds to evaluate their bone regeneration potential. The results demonstrated that PCL-silk microfiber composite scaffolds of Antheraea mylitta origin showed much higher bioactivity than the Bombyx mori ones because of arginine-glycine-aspartic acid (RGD) sequences present in the Antheraea mylitta silk fibroin protein favoring cell attachment and proliferation. By day 14, the metabolic activity of hGMSCs was highest in PCL-40AM (4.5 times higher than that at day 1). In addition, to show the translational potential of this work, we have fabricated a patient defect-specific model (mandible) using the CT scan obtained by the micro-CT imaging to understand the printability of the composite for fabricating complex structures to restore maxillofacial bony defects with precision when applied in a clinical scenario.
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Bombyx , Fibroínas , Animales , Arginina/metabolismo , Ácido Aspártico/metabolismo , Materiales Biocompatibles/química , Fibroínas/química , Glicina/metabolismo , Humanos , Oligopéptidos/metabolismo , Poliésteres , Porosidad , Impresión Tridimensional , Seda/metabolismo , Células Madre/metabolismo , Andamios del Tejido/químicaRESUMEN
There is an enormous demand for bone graft biomaterials to treat developmental and acquired bony defects arising from infections, trauma, tumor, and other conditions. Polycaprolactone (PCL) has been extensively utilized for bone tissue engineering but limited cellular interaction and tissue integration are the primary concerns. PCL-based composites with different biomaterials have been attempted to improve the mechanical and biological response. Interestingly, a few studies have tried to blend PCL with aqueous silk fibroin solution, but the structures prepared with the blend were mechanically weak due to phase mismatch. As a result, silk microparticle-based PCL composites have been prepared, but the microfibers-reinforced composites could be superior to them due to significant fiber-matrix interaction. This study aims at developing a unique composite by incorporating 100-150 µm long (aspect ratio; 8:1-5:1) silk-fibroin microfibers into the PCL matrix for superior biological and mechanical properties. Two silk variants were used, that is, Bombyx mori and a wild variant, Antheraea mylitta, reported to have cell recognizable Arginine-Glycine-Aspartic acid (RGD) sequences. A. mylitta silk fibroin microfibers were produced, and composites were made with PCL for the first time. The morphological, tensile, thermal, biodegradation, and biological properties of the composites were evaluated. Importantly, we tried to optimize the silk concentration within the composite to strike a balance among the cellular response, biodegradation, and mechanical strength of the composites. The results indicate that the PCL-silk fibroin microfiber composite could be an efficient biomaterial for bone tissue engineering.
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Bombyx , Fibroínas , Animales , Materiales Biocompatibles , Fibroínas/química , Poliésteres , Seda/química , Ingeniería de Tejidos/métodos , Andamios del Tejido/químicaRESUMEN
Zinc (Zn) deficiency in humans is an emerging global health issue affecting approximately two billion people across the globe. The situation prevails due to the intake of Zn deficient grains and vegetables worldwide. Clinical identification of Zn deficiency in humans remains problematic because the symptoms do not appear until impair the vital organs, such as the gastrointestinal track, central nervous system, immune system, skeletal, and nervous system. Lower Zn body levels are also responsible for multiple physiological disorders, such as apoptosis, organs destruction, DNA injuries, and oxidative damage to the cellular components through reactive oxygen species (ROS). The oxidative damage causes chronic inflammation lead toward several chronic diseases, such as heart diseases, cancers, alcohol-related malady, muscular contraction, and neuro-pathogenesis. The present review focused on the physiological and growth-related changes in humans under Zn deficient conditions, mechanisms adopted by the human body under Zn deficiency for the proper functioning of the body systems, and the importance of nutritional and nutraceutical approaches to overcome Zn deficiency in humans and concluded that the biofortified food is the best source of Zn as compared to the chemical supplementation to avoid their negative impacts on human.
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Exposure to respirable air particulate matter (PM2.5) in ambient air is associated with morbidity and premature deaths. A major source of PM2.5 is the photooxidation of volatile plant-produced organic compounds such as isoprene. Photochemical oxidation of isoprene leads to the formation of hydroperoxides, environmental oxidants that lead to inflammatory (IL-8) and adaptive (HMOX1) gene expression in human airway epithelial cells (HAEC). To examine the mechanism through which these oxidants alter intracellular redox balance, we used live-cell imaging to monitor the effects of isoprene hydroxyhydroperoxides (ISOPOOH) in HAEC expressing roGFP2, a sensor of the glutathione redox potential (EGSH). Non-cytotoxic exposure of HAEC to ISOPOOH resulted in a rapid and robust increase in EGSH that was independent of the generation of intracellular or extracellular hydrogen peroxide. Our results point to oxidation of GSH through the redox relay initiated by glutathione peroxidase 4, directly by ISOPOOH or indirectly by ISOPOOH-generated lipid hydroperoxides. We did not find evidence for involvement of peroxiredoxin 6. Supplementation of HAEC with polyunsaturated fatty acids enhanced ISOPOOH-induced glutathione oxidation, providing additional evidence that ISOPOOH initiates lipid peroxidation of cellular membranes. These findings demonstrate that ISOPOOH is a potent environmental airborne hydroperoxide with the potential to contribute to oxidative burden of human airway posed by inhalation of secondary organic aerosols.
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Estrés Oxidativo , Material Particulado , Butadienos , Células Epiteliales/metabolismo , Glutatión/metabolismo , Hemiterpenos , Humanos , Peróxido de Hidrógeno/farmacología , Oxidantes/farmacología , Oxidación-ReducciónRESUMEN
Clostridioides difficile infection (CDI) is a health issue of utmost significance in Europe and North America, due to its high prevalence, morbidity, and mortality rate. The clinical spectrum of CDI is broad, ranging from asymptomatic to deadly fulminant colitis. When associated with chronic kidney disease (CKD), CDI is more prevalent and more severe than in the general population, due to specific risk factors such as impaired immune system, intestinal dysmotility, high antibiotic use leading to disturbed microbiota, frequent hospitalization, and PPI use. We performed a systematic review on the issue of prevention and treatment of CDI in the CKD population, analysing the suitable randomized controlled cohort studies published between 2000 and 2021. The results show that the most important aspect of prevention is isolation and disinfection with chlorine-based solution and hydrogen peroxide vapour to stop the spread of bacteria. In terms of prevention, using Lactobacillus plantarum (LP299v) proved to be more efficient than disinfection measures in transplant patients, leading to higher cure rates and less recurrent episodes of CDI. Treatment with oral fidaxomycin is more effective than with oral vancomycin for the initial episode of CDI in CKD patients. Faecal microbiota transplantation (FMT) is more effective than vancomycin in recurrent CDI in CKD patients. More large-sample RCTs are necessary to conclude on the best treatment and prevention strategy of CDI in CKD patients.
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Infecciones por Clostridium/complicaciones , Insuficiencia Renal Crónica/complicaciones , Insuficiencia Renal Crónica/microbiología , Infecciones por Clostridium/prevención & control , Infecciones por Clostridium/terapia , Humanos , Evaluación de Resultado en la Atención de Salud , Ensayos Clínicos Controlados Aleatorios como AsuntoRESUMEN
A 67-year-old woman presented with painful, acute vision loss after 5 days of fever and muscle aches while visiting the Dominican Republic. She had no recent history of ocular surgery, dental work or recent trauma. Anterior chamber aspiration confirmed an initial diagnosis of endogenous endophthalmitis, positive for Streptococcus mitis that progressed to panophthalmitis on return to Canada. Treatment included systemic antibiotics, intravitreal antibiotics and intravitreal dexamethasone. Despite the best medical treatment, the left eye progressed to corneal perforation 5 weeks after presentation. An evisceration with fitted orbital implant was successful in alleviating pain following the surgery. S. mitis is a rare, but possible cause of endogenous endophthalmitis and panophthalmitis. It was important to work with a multidisciplinary and global team to coordinate and offer appropriate treatment measures. Although vision was lost, evisceration of the left eye provided ocular comfort and good cosmetic outcomes for the patient.
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Endoftalmitis , Panoftalmitis , Anciano , Canadá , República Dominicana , Endoftalmitis/tratamiento farmacológico , Femenino , Humanos , Estudios Retrospectivos , Streptococcus mitisRESUMEN
BACKGROUND: Globally, a large percentage of men keep a beard at least occasionally. Workplace regulations prohibit beards with N95 respirators, but there is little information on the effect of beards with face masks worn by the public for protection against SARS-CoV-2. METHODS AND FINDINGS: We examined the fitted filtration efficiency (FFE) of five commonly worn protective face masks as a function of beard length following the US Occupational Safety and Health Administration Quantitative Fit Test: N95 (respirator), KF94 and KN95, surgical/procedure, and cloth masks. A comparison using N95 respirators was carried out in shaven and bearded men. A detailed examination was conducted for beard lengths between 0 and 10 mm (0.5 mm increments). The effect of an exercise band covering the beard on FFE was also tested. Although N95 respirators showed considerable variability among bearded men, they had the highest FFE for beard lengths up to 10 mm. KF94 and KN95 masks lost up to 40% of their FFE. Procedure and cotton masks had poor performance even on bare skin (10-30% FFE) that did not change appreciably with beard length. Marked performance improvements were observed with an exercise band worn over the beard. CONCLUSIONS: Though variable, N95 respirators offer the best respiratory protection for bearded men. While KF94 and KN95 FFE is compromised considerably by increasing beard length, they proved better options than procedure and cotton face masks. A simple exercise band improves FFE for face masks commonly used by bearded men during the COVID-19 pandemic.
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COVID-19 , Dispositivos de Protección Respiratoria , Humanos , Masculino , Máscaras , Pandemias/prevención & control , Equipo de Protección Personal , SARS-CoV-2RESUMEN
2D nanomaterials (2DNMs) possess fascinating properties and are found in multifarious devices and applications including energy storage devices, new generation of battery technologies, sensor devices, and more recently in biomedical applications. Their use in biomedical applications such as tissue engineering, photothermal therapy, neural regeneration, and drug delivery has opened new horizons in treatment of age-old ailments. It is also a rapidly developing area of advanced research. A new approach of integrating 3D printing (3DP), a layer-by-layer deposition technique for building structures, along with 2DNM multifunctional inks, has gained considerable attention in recent times, especially in biomedical applications. With the ever-growing demand in healthcare industry for novel, efficient, and rapid technologies for therapeutic treatment methods, 3DP structures of 2DNMs provide vast scope for evolution of a new generation of biomedical devices. Recent advances in 3DP structures of dispersed 2DNM inks with established high-performance biomedical properties are focused on. The advantages of their 3D structures, the sustainable formulation methods of such inks, and their feasible printing methods are also covered. Subsequently, it deals with the therapeutic applications of some already researched 3DP structures of 2DNMs and concludes with highlighting the challenges as well as the future directions of research in this area.
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Tinta , Nanoestructuras , Sistemas de Liberación de Medicamentos , Impresión Tridimensional , Ingeniería de TejidosRESUMEN
Selective laser melting (SLM) is a powder bed fusion type metal additive manufacturing process which is being applied to manufacture highly customised and value-added parts in biomedical, defence, aerospace, and automotive industries. Aluminium alloy is one of the widely used metals in manufacturing parts in SLM in these sectors due to its light weight, high strength, and corrosion resistance properties. Parts used in such applications can be subjected to severe dynamic loadings and high temperature conditions in service. It is important to understand the mechanical response of such products produced by SLM under different loading and operating conditions. This paper presents a comprehensive review of the latest research carried out in understanding the mechanical properties of aluminium alloys processed by SLM under static, dynamic, different build orientations, and heat treatment conditions with the aim of identifying research gaps and future research directions.