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Platinum exhibits desirable catalytic properties, but it is scarce and expensive. Optimizing its use in key applications such as emission control catalysis is important to reduce our reliance on such a rare element. Supported Pt nanoparticles (NPs) used in emission control systems deactivate over time because of particle growth in sintering processes. In this work, we shed light on the stability against sintering of Pt NPs supported on and encapsulated in Al2O3 using a combination of nanocrystal catalysts and atomic layer deposition (ALD) techniques. We find that small amounts of alumina overlayers created by ALD on preformed Pt NPs can stabilize supported Pt catalysts, significantly reducing deactivation caused by sintering, as previously observed by others. Combining theoretical and experimental insights, we correlate this behavior to the decreased propensity of oxidized Pt species to undergo Ostwald ripening phenomena because of the physical barrier imposed by the alumina overlayers. Furthermore, we find that highly stable catalysts can present an abundance of under-coordinated Pt sites after restructuring of both Pt particles and alumina overlayers at a high temperature (800 °C) in C3H6 oxidation conditions. The enhanced stability significantly improves the Pt utilization efficiency after accelerated aging treatments, with encapsulated Pt catalysts reaching reaction rates more than two times greater than those of a control supported Pt catalyst.
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Adverse cardiac outcomes in COVID-19 patients, particularly those with preexisting cardiac disease, motivate the development of human cell-based organ-on-a-chip models to recapitulate cardiac injury and dysfunction and for screening of cardioprotective therapeutics. Here, we developed a heart-on-a-chip model to study the pathogenesis of SARS-CoV-2 in healthy myocardium established from human induced pluripotent stem cell (iPSC)-derived cardiomyocytes and a cardiac dysfunction model, mimicking aspects of preexisting hypertensive disease induced by angiotensin II (Ang II). We recapitulated cytopathic features of SARS-CoV-2-induced cardiac damage, including progressively impaired contractile function and calcium handling, apoptosis, and sarcomere disarray. SARS-CoV-2 presence in Ang II-treated hearts-on-a-chip decreased contractile force with earlier onset of contractile dysfunction and profoundly enhanced inflammatory cytokines compared to SARS-CoV-2 alone. Toward the development of potential therapeutics, we evaluated the cardioprotective effects of extracellular vesicles (EVs) from human iPSC which alleviated the impairment of contractile force, decreased apoptosis, reduced the disruption of sarcomeric proteins, and enhanced beta-oxidation gene expression. Viral load was not affected by either Ang II or EV treatment. We identified MicroRNAs miR-20a-5p and miR-19a-3p as potential mediators of cardioprotective effects of these EVs.
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Angiotensina II , COVID-19 , Células-Tronco Pluripotentes Induzidas , Dispositivos Lab-On-A-Chip , Miócitos Cardíacos , Humanos , Angiotensina II/farmacologia , Apoptose/efeitos dos fármacos , COVID-19/virologia , COVID-19/metabolismo , Citocinas/metabolismo , Vesículas Extracelulares/metabolismo , Células-Tronco Pluripotentes Induzidas/metabolismo , MicroRNAs/metabolismo , MicroRNAs/genética , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/virologia , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/patologia , SARS-CoV-2/fisiologiaRESUMO
BACKGROUND: Children with Spina Bifida (SB) have considerable healthcare utilization, including Emergency Department use (EDU). We aimed to elicit reasons for EDU using qualitative analysis of interviews with both patient-caregiver dyads and stakeholders. METHODS: A cohort of children with SB followed at our institution between 2016 and 2020 was identified and patient and clinical characteristics abstracted. Purposeful sampling by age and degree of past EDU was performed. Semi-structured interviews of dyads were performed using iteratively revised interview guides. Spanish-language interviews were conducted by a native Spanish speaker and transcripts professionally translated. Supplemental interviews with stakeholders, namely knowledgeable healthcare professionals, were also conducted. A qualitative framework approach was used for analysis, including open followed by closed independent coding with calculation of inter-rater reliability. A final interpretation of coding reports assessing convergence, divergence, and variation in themes across participant characteristics. RESULTS: 116 families (4 Spanish-speaking) and 7 stakeholders were interviewed. Sampling yielded a heterogenous cohort for EDU (56% with 0-10, 44% with >10 visits) and age (25% 0-4, 44% 5-11, 31% > 11 years). IRR was optimal (κ = 0.9). Themes in perceived reasons for EDU were 1) desire for "one-stop-shop" care, 2) an emergent medical problem, 3) providers' instructions, 4) negative past healthcare experience, 5) intrinsic caregiver moderators, and 6) temporospatial influences. Themes 1, 2, and 5 predominated in dyads, whereas themes 6, 3, and 5 were most common in stakeholders. Stakeholders focused largely on negative institutional and patient characteristics. Among dyads only, theme #1 was disproportionately emphasized by Spanish-speaking patients. DISCUSSION: Families desired access to coordinated expert care, testing and imaging. The ED offers this for children with SB, regardless of clinical acuity. This may be especially valued by families with inherent challenges to navigating the healthcare system. Negative experiences in community clinical settings, healthcare provider recommendations and intrinsic parental factors were themes that seemed to contribute to seeking this "one-stop-shop" type of care. Care coordination may reduce ED reliance, but themes for the interviews suggest a systems-based efforts should weave in the community care setting. CONCLUSIONS: For both stakeholders and caregivers, the ED represented a valued form of immediate access to multispecialty, expert care and testing in the context of perceived lack of timely, coordinated outpatient care. This may be moderated by intrinsic caregiver factors and negative past experiences. Although stakeholders discussed ideas that fit into patient-caregiver themes, the also uniquely focused on systems-based and patient-caregiver limitations.
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The most serious types of heat illnesses, heat exhaustion and heat stroke, are occupational hazards associated with many of the military's training and operational environments. These illnesses can typically be prevented by appropriate situational awareness, risk management strategies, along with effective countermeasures. In 2023, the crude incidence of heat stroke and heat exhaustion were 31.7 and 172.7 cases per 100,000 person-years, respectively. The rates of incident heat stroke declined during the 2019 to 2023 surveillance period, but rates of incident heat exhaustion increased over the same period. In 2023, higher rates of heat stroke were observed among male service members compared to their female counterparts, and female service members experienced higher rates of heat exhaustion compared to male personnel. Heat illness rates were also higher among those younger than age 20, Marine Corps and Army service members, non-Hispanic Black service members, and recruits. Leaders, training cadres, and supporting medical and safety personnel must inform their subordinate and supported service members of heat illness risks, preventive measures, early signs and symptoms of illness, and appropriate interventions.
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Exaustão por Calor , Golpe de Calor , Militares , Doenças Profissionais , Humanos , Militares/estatística & dados numéricos , Estados Unidos/epidemiologia , Feminino , Adulto , Masculino , Golpe de Calor/epidemiologia , Adulto Jovem , Exaustão por Calor/epidemiologia , Incidência , Doenças Profissionais/epidemiologia , Vigilância da População , Transtornos de Estresse por Calor/epidemiologiaRESUMO
Background Patients often turn to online reviews as a source of information to inform their decisions regarding care. Existing literature has analyzed factors associated with positive online patient ratings among hand and wrist surgeons. However, there is limited in-depth analysis of factors associated with low patient satisfaction for hand and wrist surgeons. The focus of this study is to examine and characterize extremely negative reviews of hand and wrist surgeons on Yelp.com. Methods A search was performed using the keywords "hand surgery" on Yelp.com for eight major metropolitan areas including Washington DC, Dallas, New York, Phoenix, Los Angeles, San Francisco, Boston, and Seattle. Only single-star reviews (out of a possible 5 stars) of hand and wrist surgeons were included. The complaints in the 1-star reviews were then categorized into clinical and nonclinical categories. Result A total of 233 single-star reviews were included for analysis, which resulted in 468 total complaints. Of these complaints, 81 (18.8%) were clinically related and 351 (81.3%) were nonclinical in nature. The most common clinical complaints were for complication (24 complaints, 6%), misdiagnosis (16 complaints, 4%), unclear treatment plan (16 complaints, 4%), and uncontrolled pain (15 complaints, 3%). The most common nonclinical complaints were for physician bedside manner (93 complaints, 22%), financially related (80 complaints, 19%), unprofessional nonclinical staff (61 complaints, 14%), and wait time (46 complaints, 11%). The difference in the number of complaints for surgical and nonsurgical patients was statistically significant ( p < 0.05) for complication and uncontrolled pain. Clinical Relevance Patient satisfaction is dependent on a multitude of clinical and nonclinical factors. An awareness of online physician ratings is essential for hand and wrist surgeons to maintain and improve patient care and patient satisfaction. We believe the results of our study could be used to further improve the quality of care provided by hand and wrist surgeons.
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Metal-organic frameworks (MOFs) have shown promise for adsorptive separations of metal ions. Herein, MOFs based on highly stable Zr(IV) building units were systematically functionalized with targeted metal binding groups. Through competitive adsorption studies, it was shown that the selectivity for different metal ions was directly tunable through functional group chemistry.
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In mammals, the circadian clock network drives daily rhythms of tissue-specific homeostasis. To dissect daily inter-tissue communication, we constructed a mouse minimal clock network comprising only two nodes: the peripheral epidermal clock and the central brain clock. By transcriptomic and functional characterization of this isolated connection, we identified a gatekeeping function of the peripheral tissue clock with respect to systemic inputs. The epidermal clock concurrently integrates and subverts brain signals to ensure timely execution of epidermal daily physiology. Timely cell-cycle termination in the epidermal stem cell compartment depends upon incorporation of clock-driven signals originating from the brain. In contrast, the epidermal clock corrects or outcompetes potentially disruptive feeding-related signals to ensure the optimal timing of DNA replication. Together, we present an approach for cataloging the systemic dependencies of daily temporal organization in a tissue and identify an essential gate-keeping function of peripheral circadian clocks that guarantees tissue homeostasis.
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Encéfalo , Relógios Circadianos , Epiderme , Homeostase , Animais , Relógios Circadianos/fisiologia , Relógios Circadianos/genética , Epiderme/metabolismo , Epiderme/fisiologia , Camundongos , Encéfalo/fisiologia , Encéfalo/metabolismo , Transdução de Sinais , Pele/metabolismo , Camundongos Endogâmicos C57BL , Ritmo Circadiano/fisiologiaRESUMO
Trace palladium in synthetic materials can be rapidly and inexpensively semiquantified by a catalysis-based fluorometric method that converts resorufin allyl ether to resorufin. However, whether sulfur compounds would interfere with this method has not been systematically studied. Herein, we show that although thiourea in solution interferes with quantification, sulfide, thiol, and thiocarbamate do not. The fluorometric method can also detect palladium bound to sulfur-based scavenger resin and outperform inductively coupled plasma mass spectrometry for detecting trace palladium in ibuprofen.
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Fluorometria , Ibuprofeno , Paládio , Paládio/química , Ibuprofeno/química , Ibuprofeno/análise , Catálise , Fluorometria/métodos , Estrutura Molecular , Compostos de Enxofre/química , Compostos de Enxofre/análiseRESUMO
OBJECTIVE: To identify factors associated with overtreatment of presumed urinary tract infection (UTI) among children with spina bifida using such criteria. STUDY DESIGN: A retrospective review of children with spina bifida (age <21 years) evaluated in the Emergency Department (ED) at a single institution was performed. Patients with a urinalysis (UA) performed who were reliant on assisted bladder emptying were included. The primary outcome was overtreatment, defined as receiving antibiotics for presumed UTI but ultimately not meeting spina bifida UTI criteria (≥2 urologic symptoms plus pyuria and urine culture growing >100k CFU/mL). The primary exposure was whether the components of the criteria available at the time of the ED visit (≥2 urologic symptoms plus pyuria) were met when antibiotics were initiated. RESULTS: Among 236 ED encounters, overtreatment occurred in 80% of cases in which antibiotics were initiated (47% of the entire cohort). Pyuria with <2 urologic symptoms was the most important factor associated with overtreatment (OR 9.6). Non-Hispanic White race was associated with decreased odds of overtreatment (OR 0.3). CONCLUSIONS: Overtreatment of presumed UTI among patients with spina bifida was common. Pyuria, which is not specific to UTI in this population, was the main driver of overtreatment. Symptoms are a cornerstone of UTI diagnosis among children with spina bifida, should be collected in a standardized manner, and considered in a decision to treat.
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A molecular clock network is crucial for daily physiology and maintaining organismal health. We examined the interactions and importance of intratissue clock networks in muscle tissue maintenance. In arrhythmic mice showing premature aging, we created a basic clock module involving a central and a peripheral (muscle) clock. Reconstituting the brain-muscle clock network is sufficient to preserve fundamental daily homeostatic functions and prevent premature muscle aging. However, achieving whole muscle physiology requires contributions from other peripheral clocks. Mechanistically, the muscle peripheral clock acts as a gatekeeper, selectively suppressing detrimental signals from the central clock while integrating important muscle homeostatic functions. Our research reveals the interplay between the central and peripheral clocks in daily muscle function and underscores the impact of eating patterns on these interactions.
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Senilidade Prematura , Envelhecimento , Encéfalo , Ritmo Circadiano , Músculo Esquelético , Animais , Masculino , Camundongos , Envelhecimento/genética , Envelhecimento/fisiologia , Senilidade Prematura/genética , Senilidade Prematura/prevenção & controle , Encéfalo/fisiologia , Relógios Circadianos/fisiologia , Ritmo Circadiano/genética , Ritmo Circadiano/fisiologia , Homeostase , Músculo Esquelético/fisiologia , Camundongos Knockout , Fatores de Transcrição ARNTL/genéticaRESUMO
A retrospective cohort study of patients undergoing laparoscopic inguinal hernia repair compared short- and long-term outcomes between individuals with or without history of previous abdominopelvic surgery, aiming to determine the feasibility of totally extraperitoneal (TEP) repair within this population. All patients who underwent elective TEP inguinal hernia repair by one consultant surgeon across three London hospitals from January 2017 to May 2023 were retrospectively analysed to assess perioperative outcomes. Two hundred sixty-two patients were identified, of whom two hundred forty-three (93%) underwent laparoscopic TEP repair. The most frequent complications were haematoma (6.2%) and seroma (4.1%). Recurrence occurred in four cases (1.6% of operations, 1.1% of hernias). One hundred eighty-four patients (76%) underwent day-case surgery. There were no mesh infections or explanations, vascular or visceral injuries, port-site hernias, damage to testicle, or persisting numbness. There were no requirements for blood transfusion, returns to theatre, or readmissions within 30 days. There was one conversion to open and one death within 60 days of surgery. Eighty-three (34%) had a history of previous AP surgery. There was no significant difference in perioperative outcomes between the AP and non-AP arms. This finding carried true for subgroup analysis of 44 patients whose AP surgical history did not include previous inguinal hernia repair and for those undergoing repair of recurrent hernia. In expert hands, laparoscopic TEP repair is associated with excellent outcomes and low rates of long-term complications, and thus should be considered as standard for patients regardless of a history of AP surgery.
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The direct observation of a solid-state chemical reaction can reveal otherwise hidden mechanisms that control the reaction kinetics. However, probing the chemical bond breaking and formation at the molecular level remains challenging because of the insufficient spatial-temporal resolution and composition analysis of available characterization methods. Using atomic-resolution differential phase-contrast imaging in scanning transmission electron microscopy, we have visualized the decomposition chemistry of K2PtCl4 to identify its transient intermediate phases and their interfaces that characterize the chemical reduction process. The crystalline structure of K2PtCl4 is found to undergo a disproportionation reaction to form K2PtCl6, followed by gradual reduction to crystalline Pt metal and KCl. By directly imaging different PtâCl bond configurations and comparing them to models predicted via density functional theory calculations, a causal connection between the initial and final states of a chemical reaction is established, showcasing new opportunities to resolve reaction pathways through atomistic experimental visualization.
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Environmental surveillance of pathogens underlying infectious disease is critical to ensure public health. Recent efforts to track SARS-CoV-2 have utilized wastewater sampling to infer community trends in viral abundance and variant composition. Indoor dust has also been used for building-level inferences, though to date no sequencing data providing variant-scale resolution have been reported from dust samples, and strategies to monitor circulating variants in dust are needed to help inform public health decisions. In this study, we demonstrate that SARS-CoV-2 lineages can be detected and sequenced from indoor bulk dust samples. We collected 93 vacuum bags from April 2021 to March 2022 from buildings on The Ohio State University's (OSU) Columbus campus, and the dust was used to develop and apply an amplicon-based whole-genome sequencing protocol to identify the variants present and estimate their relative abundances. Three variants of concern were detected in the dust: Alpha, Delta, and Omicron. Alpha was found in our earliest sample in April 2021 with an estimated frequency of 100%. Delta was the primary variant present from October of 2021 to January 2022, with an average estimated frequency of 91% (±1.3%). Omicron became the primary variant in January 2022 and was the dominant strain in circulation through March with an estimated frequency of 87% (±3.2%). The detection of these variants on OSU's campus correlates with the circulation of these variants in the surrounding population (Delta p<0.0001 and Omicron p = 0.02). Overall, these results support the hypothesis that dust can be used to track COVID-19 variants in buildings.
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COVID-19 , SARS-CoV-2 , Humanos , SARS-CoV-2/genética , COVID-19/epidemiologia , Poeira , Monitoramento AmbientalRESUMO
Medicinal chemists use vast combinatorial molecular libraries to develop leads for new pharmaceuticals. The syntheses of these compounds typically rely on coupling molecular fragments through atoms with planar (sp2) geometry. These so-called flat molecules often lack the protein binding site specificity needed to be an effective drug. Here, we demonstrate a coupling strategy in which a cyclohexene is used as a linker to connect two diverse molecular fragments while forming two new tetrahedral (sp3) stereocenters. These connections are made with the aid of a tungsten complex that activates anisole toward an unusual double protonation, followed by sequential nucleophilic additions. As a result, either cis- or trans-disubstituted cyclohexenes can be prepared with a range of chemical diversity unparalleled by other dearomatization methods.
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Soils at many contaminated sites have accumulated a significant amount of per- and polyfluoroalkyl substances (PFAS) and may require remediation to mitigate leaching to groundwater. USEPA's current approaches for determining soil screening levels (SSLs) were developed for non-PFAS contaminants. Because many PFAS are interfacially-active with unique leaching behaviors in soils, the current non-PFAS-specific soil screening models may not be applicable. Following USEPA's general methodology, we develop a new modeling framework representing PFAS-specific transport processes for determining site-specific SSLs for PFAS-contaminated sites. We couple a process-based analytical model for PFAS leaching in the vadose zone and a dilution factor model for groundwater in an integrated framework. We apply the new modeling framework to two typical types of contaminated sites. Comparisons with the standard USEPA SSL approach suggest that accounting for the PFAS-specific transport processes may significantly increase the SSL for some PFAS. For the range of soil properties and groundwater recharge rates examined, while SSLs determined with the new model are less than a factor of 2 different from the standard-model values for less interfacially-active shorter-chain PFAS, they are up to two orders of magnitudes greater for more interfacially-active longer-chain PFAS. The new analytical modeling framework provides an effective tool for deriving more accurate site-specific SSLs and improving site characterization and remedial efforts at PFAS-contaminated sites.
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Fluorocarbonos , Água Subterrânea , Poluentes Químicos da Água , Solo , Poluentes Químicos da Água/análise , Fluorocarbonos/análiseRESUMO
OBJECTIVE: To describe initial experience with use of the Glidescope Go videolaryngoscope by an Australian neonatal pre-hospital and retrieval service. METHODS: We conducted a 31-month retrospective review of an airway registry for neonates intubated by MedSTAR Kids clinicians. RESULTS: Twenty-two patients were intubated using the Glidescope Go, compared with 50 using direct laryngoscopy. First-pass success was 17/22 (77.3%) with the Glidescope Go and 38/50 (76%) with direct laryngoscopy. Complications occurred in 7/22 (32%) and 8/50 (16%), respectively. CONCLUSIONS: On initial review of this practice change, videolaryngoscopy allows neonatal tracheal intubation with a comparable success rate to direct laryngoscopy in a pre-hospital and retrieval setting.
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Intubação Intratraqueal , Laringoscopia , Gravação em Vídeo , Humanos , Estudos Retrospectivos , Recém-Nascido , Laringoscopia/métodos , Laringoscopia/instrumentação , Intubação Intratraqueal/métodos , Intubação Intratraqueal/instrumentação , Masculino , Feminino , Gravação em Vídeo/métodos , Serviços Médicos de Emergência/métodos , Laringoscópios , AustráliaRESUMO
Due to the large multi-elemental space desired for property screening and optimization, high-entropy alloys (HEAs) hold greater potential over conventional alloys for a range of applications, such as structural materials, energy conversion, and catalysis. However, the relationship between the HEA composition and its local structural/elemental configuration is not well understood, particularly in noble-metal-based HEA nanomaterials, hindering the design and development of nano-HEAs in energy conversion and catalysis applications. Herein, we determined precise atomic-level structural and elemental arrangements in model HEAs composed of RhPtPdFeCo and RuPtPdFeCo to unveil their local characteristics. Notably, by changing just one constituent element in the HEA (Rh to Ru), we found dramatic changes in the elemental arrangement from complete random mixing to a local single elemental ordering feature. Additionally, we demonstrate that the local ordering in RuPtPdFeCo can be further controlled by varying the Ru concentration, allowing us to toggle between local Ru clustering and distinct heterostructures in multicomponent systems. Overall, our study presents a practical approach for manipulating local atomic structures and elemental arrangements in noble-metal-based HEA systems, which could provide in-depth knowledge to mechanistically understand the functionality of noble-metal-based HEA nanomaterials in practical applications.
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Mechanical load is one of the main determinants of cardiac structure and function. Mechanical load is studied in vitro using cardiac preparations together with loading protocols (e.g., auxotonic, isometric). However, such studies are often limited by reductionist models and poorly simulated mechanical load profiles. This hinders the physiological relevance of findings. Living myocardial slices have been used to study load in vitro. Living myocardial slices (LMS) are 300-µm-thick intact organotypic preparations obtained from explanted animal or human hearts. They have preserved cellular populations and the functional, structural, metabolic and molecular profile of the tissue from which they are prepared. Using a three-element Windkessel (3EWK) model we previously showed that LMSs can be cultured while performing cardiac work loops with different preload and afterload. Under such conditions, LMSs remodel as a function of the mechanical load applied to them (physiological load, pressure or volume overload). These studies were conducted in commercially available length actuators that had to be extensively modified for culture experiments. In this paper, we demonstrate the design, development and validation of a novel device, MyoLoop. MyoLoop is a bioreactor that can pace, thermoregulate, acquire and process data, and chronically load LMSs and other cardiac tissues in vitro. In MyoLoop, load is parametrised using a 3EWK model, which can be used to recreate physiological and pathological work loops and the remodelling response to these. We believe MyoLoop is the next frontier in basic cardiovascular research enabling reductionist but physiologically relevant in vitro mechanical studies.
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Reatores Biológicos , Coração , Animais , Humanos , Miocárdio , Projetos de PesquisaRESUMO
Atomically dispersed cerium catalysts on an inert, crystalline MgO powder support were prepared by using both Ce(III) and Ce(IV) precursors. The materials were used as catalysts for CO oxidation in a once-through flow reactor and characterized by atomic-resolution scanning transmission electron microscopy, X-ray absorption near-edge structure spectroscopy, X-ray photoelectron spectroscopy, and temperature-programmed reduction, among other techniques, before and after catalysis. The most active catalysts, formed from the precursor incorporating Ce(III), displayed performance similar to that reported for bulk ceria under comparable conditions. The catalyst provided stable time-on-stream performance for as long as it was kept on-stream, 2 days, increasing slightly in activity as the atomically dispersed cerium ions were transformed into ceria nanodomains represented as CeOx and having increased reducibility on the MgO support. The results suggest how highly dispersed supported ceria catalysts with low cerium loadings can be prepared and may pave the way for improved efficiencies of cerium utilization in oxidation catalysis.