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Bridging synthetic chemistry and computational methods: studying the stability and reactivity of metal-binding macrocycles
No full textThe stability constant (log KML = log β) of metal complexes is a critical thermodynamic parameter, providing valuable insights into the stability and formation dynamics of these complexes. Traditionally, stability constants have been central in analytical chemistry, aiding in metal ion speciation and selectivity. However, they are equally crucial in fields such as catalysis, therapeutic development, and energy applications, where understanding the stability of metal complexes informs their robustness and applicability. Beyond thermodynamic stability, the log β value also influences the reactivity of inorganic complexes; commonly, highly stable complexes tend to have diminished reactivity, whereas less stable complexes may lack the necessary ligand-mediated control over metal reactivity due to their tendency to dissociate.
In this context, macrocyclic ligands are often employed to achieve highly stable metal complexes, as they leverage the chelate effect of multidentate binding alongside an optimal ion-size match. Such stability makes macrocycles particularly useful for applications in drug delivery, therapeutic imaging, and catalysis. Yet, balancing stability with reactivity remains a significant challenge. High-throughput organic synthesis offers a potential solution by generating ligand libraries, though this approach can be resource-intensive and often produces compounds unsuitable for specific applications. As a result, other approaches are necessary.
This dissertation investigates the role of the log β parameter in guiding the speciation and reactivity of transition metals complexed with 12-membered pyridinophane macrocycles. Initially, we examine Mn(II) complexes, illustrating how the stability constant influenced both the reactivity of high-valent manganese ions, and the synthetic approaches used. Subsequently, we developed a computational workflow to refine the predictive accuracy of stability constants, beginning with closed-shell Zn(II) complexes and extending to open-shell Cu(II) complexes. This work advances the understanding of stability-reactivity relationships in metal complexes, offering computational insights that enhance ligand design and complexation strategies in diverse applications
Inhibition of host 5-lipoxygenase reduces overexuberant inflammatory responses and mortality associated with Cryptococcus meningoencephalitis
No full textCryptococcosis, caused by fungi of the genus Cryptococcus, manifests in a broad range of clinical presentations, including severe pneumonia and disease of the central nervous system (CNS) and other tissues (bone and skin). Immune deficiency or development of overexuberant inflammatory responses can result in increased susceptibility or host damage, respectively, during fungal encounters. Leukotrienes help regulate inflammatory responses against fungal infections. Nevertheless, studies showed that Cryptococcus exploits host 5-lipoxygenase (5-LO), an enzyme central to the metabolism of arachidonic acid into leukotrienes, to facilitate transmigration across the brain�blood barrier. To investigate the impact of host 5-LO on the development of protective host immune responses and mortality during cryptococcosis, wild-type (C57BL/6) and 5-lipoxygenase-deficient (5-LO?/?) mice were given experimental pulmonary and systemic Cryptococcus sp., infections. Our results showed that 5-LO?/? mice exhibited reduced pathology and better disease outcomes (i.e., no mortality or signs associated with cryptococcal meningoencephalitis) following pulmonary infection with C. deneoformans, despite having detectable yeast in the brain tissues. In contrast, C57BL/6 mice exhibited classical signs associated with cryptococcal meningoencephalitis. Additionally, brain tissues of 5-LO?/? mice exhibited lower levels of cytokines (CCL2 and CCL3) clinically associated with Cryptococcus-related immune reconstitution inflammatory syndrome (C-IRIS). In a systemic mouse model of cryptococcosis, 5-LO?/? mice and those treated with a Federal Drug Administration (FDA)-approved 5-LO synthesis inhibitor, zileuton, displayed significantly reduced mortality compared to C57BL/6 infected mice. These results suggest that therapeutics designed to inhibit host 5-LO signaling could reduce disease pathology and mortality associated with cryptococcal meningoencephalitis
Frustrative Nonreward: Behavior, Circuits, Neurochemistry, and Disorders.
No full textThe surprising omission or reduction of vital resources (food, fluid, social partners) can induce an aversive emotion known as frustrative nonreward (FNR), which can influence subsequent behavior and physiology. FNR is an integral mediator of irritability/aggression, motivation (substance use disorders, depression), anxiety/fear/threat, learning/conditioning, and social behavior. Despite substantial progress in the study of FNR during the twentieth century, research lagged in the later part of the century and into the early twenty-first century until the National Institute of Mental Health's Research Domain Criteria initiative included FNR and loss as components of the negative valence domain. This led to a renaissance of new research and paradigms relevant to basic and clinical science alike. The COVID-19 pandemic's extensive individual and social restrictions were correlated with increased drug and alcohol use, social conflict, irritability, and suicide, all potential consequences of FNR. This article highlights animal models related to these psychiatric disorders and symptoms and presents recent advances in identifying the brain regions and neurotransmitters implicated
Operationalizing the Healthcare Simulation Standards of Best Practice (HSSOBPTM) to avoid training scars: An interprofessional exemplar
No full textTraining scars represent residual performance habits and psychological damage when facilitators or peers fail to help learners improve during training. Originally recognized by emergency response professionals, training scars negatively influence providers’ mental health, workforce attrition, patient safety, and the future of our professions. Simulation facilitators need to be mindful that learners experience training scars, particularly when patient safety events occur in simulation without enough debriefing or expert facilitation to unpack associated emotions. The purpose of this conceptual paper is to raise awareness of training scars across disciplines and to tell the story of how expert facilitation can prevent training scars after patient safety events. An interprofessional exemplar is presented with recommendations for operationalizing the Healthcare Simulation Standards of Best PracticeTM (HSSOBPTM) to avoid simulation training scars
Diagnostic and therapeutic considerations in cases of civilian intravascular ballistic embolism: a review of case reports
No full textBackground: Ballistic embolism (BE) is a rare complication of firearm injuries notoriously associated with a vexing clinical picture in the trauma bay. Unless considered early, the associated confusion can lead to needless delay in the management of the patient with a gunshot wound. Despite this known entity, there is a relative paucity of high-grade evidence regarding complications, management, and follow-up in these patients. Methods: An electronic database literature search was conducted to identify cases of acute intravascular BE in pediatric and adult civilians occurring during index hospitalization, filtered to publications during the past 10 years. Exclusion criteria included non-vascular embolization, injuries occurring in the military setting, and delayed migration defined as occurring after discharge from the index hospitalization. Results: A total of 136 cases were analyzed. Nearly all cases of BE occurred within 48 hours of presentation. Compared with venous emboli, arterial emboli were significantly more likely to be symptomatic (71% vs. 7%, p<0.001), and 43% of patients developed symptoms attributable to BE in the trauma bay. In addition, arterial emboli were significantly less likely to be managed non-invasively (19% vs. 49%, p<0.001). Open retrieval was significantly more likely to be successful compared with endovascular attempts (91% vs. 29%, p<0.001). Patients with arterial emboli were more likely to receive follow-up (52% vs. 39%) and any attempt at retrieval during the hospitalization was significantly associated with outpatient follow-up (p=0.034). All but one patient remained stable or had clinically improved symptoms after discharge. Conclusion: Consideration for BE is reasonable in any patient with new or persistent unexplained signs or symptoms, especially during the first 48 hours after a penetrating firearm injury. Although venous BE can often be safely observed, arterial BE generally necessitates urgent retrieval. Patients who are managed non-invasively may benefit from follow-up in the first year after injury
Carbon Dating the Early Milky Way: Extending the [C/N]-Age Calibration for Galactic Archeology
No full textIn the pursuit of unraveling the evolution of our Milky Way, we need a reliable age determination method. Astronomers often use star clusters to age-date areas of our Galaxy due to their shared kinematic, chemical, and age properties. However, these star clusters are limited in number and location throughout the Galaxy, and there are billions of isolated stars which cannot be age-dated reliably through this method. In previous work, the carbon-to-nitrogen abundance ([C/N]) has been empirically linked to stellar ages using red giant branch stars in open clusters. However, this work was limited to metal-rich open clusters. To broaden the range of metallicities that can be probed, we incorporate globular clusters. Globular clusters are ideal for our extension because of their more metal-poor metallicities and older ages. In this work, we expand the empirical relationship between [C/N] and stellar ages for two metal-poor globular clusters (M4 and M5), using stellar abundances provided by the SDSS/APOGEE DR17 survey and ages from the HST/ACS Treasury survey. Our improved calibration now covers a metallicity range of -1.2 ≤ [Fe/H] ≤ +0.3, which can be used to age-date over 45% of all SDSS/APOGEE DR17 cataloged stars in our Milky Way galaxy
REACHING CONSUMERS IN SUSTAINABLE FASHION - ANALYZING THE TENETS OF SUCCESS AMONG MARKETING STRATEGIES FOR SUSTAINABLE FASHION BRANDS
No full textToday's consumers are becoming increasingly concerned with the consequences that unsustainable practices have on people and the planet. This shift has led to a widely expanding market for socially responsible products, with an especially heightened opportunity in the fashion industry due to the more widely known consequences of fast fashion. Many new and established brands are taking this opportunity to introduce socially responsible products in the hopes of gaining and maintaining a slice of the market share. However, only a few brands are successful in gaining consumer awareness, approval, and finally; loyalty. This thesis seeks to investigate the key principles behind developing a successful marketing strategy for sustainable fashion brands, with the goal of establishing a blueprint for success in the industry. To achieve this, this thesis will begin by identifying and compiling previously realized tenets through a comprehensive review of existing research on sustainability and fashion marketing. Subsequently, these principles will be compared against the actual marketing strategies employed by six successful sustainable fashion brands. The final set of tenets will be proposed from this comparative analysis, providing a clear framework for developing effective marketing strategies in the sustainable fashion sector
Coping self-efficacy and social support as predictors of adolescent sex trafficking exit: Results of a secondary analysis
No full textIntroduction Social work case management services are increasingly available to youth who want to exit commercial sexual exploitation (CSE). However, few empirical studies investigate the efficacy of such services, particularly whether these services promote an exit from CSE. Guided by ecological systems theory and the Intentions to Exit Prostitution (IEP) model, this study investigates the efficacy of social work case management services for youth CSE survivors. Methods Youth survivors of CSE ( n = 95) participated in a one-group, quasi-experimental double pre/posttest design study. Measures included the Multidimensional Scale of Perceived Social Support (MSPSS), Coping Self-Efficacy Scale (Cop-SE), and a modified version of the University of Rhode Island Change Assessment (URICA) surveys at zero- and six-months following study commencement. The research team also collected demographic and victimization data, the number and type of social work case management services received, and goal plan data. Analyses included repeated measures tests and linear and multinomial logistic regressions to determine if doses of social work case management are predictive of the positive short-term outcomes that are linked to increased readiness to exit CSE. Results Youth CSE survivors experienced upward trends in perceived social support and coping self-efficacy scores between zero- and six-months following study commencement. Linear and logistic regressions demonstrated that variables like months of service time, trafficking classification, goal counts, race, and age can predict outcomes like survivor social support, coping self-efficacy, and intention to change behaviors that can lead to revictimization. Implications Results suggest social work case management services that improve coping self-efficacy and perceived social support can lead to cognitive changes that promote an exit from CSE. Practitioners should target services that adhere to dimensions of the IEP as these improvements are likely to support positive outcomes for youth survivors of CSE
Using natural language processing in emergency medicine health service research: A systematic review and meta-analysis
No full textObjectives: Natural language processing (NLP) represents one of the adjunct technologies within artificial intelligence and machine learning, creating structure out of unstructured data. This study aims to assess the performance of employing NLP to identify and categorize unstructured data within the emergency medicine (EM) setting. Methods: We systematically searched publications related to EM research and NLP across databases including MEDLINE, Embase, Scopus, CENTRAL, and ProQuest Dissertations and Theses Global. Independent reviewers screened, reviewed, and evaluated article quality and bias. NLP usage was categorized into syndromic surveillance, radiologic interpretation, and identification of specific diseases/events/syndromes, with respective sensitivity analysis reported. Performance metrics for NLP usage were calculated and the overall area under the summary of receiver operating characteristic curve (SROC) was determined.ResultsA total of 27 studies underwent meta-analysis. Findings indicated an overall mean sensitivity (recall) of 82%-87%, specificity of 95%, with the area under the SROC at 0.96 (95% CI 0.94-0.98). Optimal performance using NLP was observed in radiologic interpretation, demonstrating an overall mean sensitivity of 93% and specificity of 96%.Conclusions: Our analysis revealed a generally favorable performance accuracy in using NLP within EM research, particularly in the realm of radiologic interpretation. Consequently, we advocate for the adoption of NLP-based research to augment EM health care management