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Type-II quantum dots (QDs) are capable of light-driven charge separation between their core and the shell structures; however, their light absorption is limited in the longer-wavelength range. Biological light-harvesting complex II (LHCII) efficiently absorbs in the blue and red spectral domains. Therefore, hybrid complexes of these two structures may be promising candidates for photovoltaic applications. Previous measurements had shown that LHCII bound to QD can transfer its excitation energy to the latter, as indicated by the fluorescence emissions of LHCII and QD being quenched and sensitized, respectively. In the presence of methyl viologen (MV), both fluorescence emissions are quenched, indicating an additional electron transfer process from QDs to MV. Transient absorption spectroscopy confirmed this notion and showed that electron transfer from QDs to MV is much faster than fluorescence energy transfer between LHCII and QD. The action spectrum of MV reduction by LHCII-QD complexes reflected the LHCII absorption spectrum, showing that light absorbed by LHCII and transferred to QDs increased the efficiency of MV reduction by QDs. Under continuous illumination, at least 28 turnovers were observed for the MV reduction. Presumably, the holes in QD cores were filled by a reducing agent in the reaction solution or by the dihydrolipoic-acid coating of the QDs. The LHCII-QD construct can be viewed as a simple model of a photosystem with the QD component acting as reaction center.
Assuntos
Complexos de Proteínas Captadores de Luz/química , Nanopartículas/química , Complexo de Proteína do Fotossistema II/química , Semicondutores , Clorofila/química , Clorofila/metabolismo , Transporte de Elétrons , Transferência Ressonante de Energia de Fluorescência , Complexos de Proteínas Captadores de Luz/metabolismo , Paraquat/química , Pisum sativum/química , Pisum sativum/metabolismo , Complexo de Proteína do Fotossistema II/metabolismo , Pontos QuânticosRESUMO
OBJECTIVE: Focal seizure symptoms (FSS) and focal interictal epileptiform discharges (IEDs) are common in patients with idiopathic generalized epilepsies (IGEs), but dedicated studies systematically quantifying them both are lacking. We used automatic IED detection and localization algorithms and correlated these EEG findings with clinical FSS for the first time in IGE patients. METHODS: 32 patients with IGEs undergoing long-term video EEG monitoring were systematically analyzed regarding focal vs. generalized IEDs using automatic IED detection and localization algorithms. Quantitative EEG findings were correlated with FSS. RESULTS: We observed FSS in 75% of patients, without significant differences between IGE subgroups. Mostly varying/shifting lateralizations of FSS across successive recorded seizures were seen. We detected a total of 81,949 IEDs, whereof 19,513 IEDs were focal (23.8%). Focal IEDs occurred in all patients (median 13% focal IEDs per patient, range 1.1 - 51.1%). Focal IED lateralization and localization predominance had no significant effect on FSS. CONCLUSIONS: All included patients with IGE showed focal IEDs and three-quarter had focal seizure symptoms irrespective of the specific IGE subgroup. Focal IED localization had no significant effect on lateralization and localization of FSS. SIGNIFICANCE: Our findings may facilitate diagnostic and treatment decisions in patients with suspected IGE and focal signs.
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Eletroencefalografia , Epilepsia Generalizada , Humanos , Epilepsia Generalizada/fisiopatologia , Epilepsia Generalizada/diagnóstico , Eletroencefalografia/métodos , Eletroencefalografia/normas , Masculino , Feminino , Adulto , Adolescente , Adulto Jovem , Pessoa de Meia-Idade , CriançaRESUMO
Background: Machine learning (ML) models can handle large data sets without assuming underlying relationships and can be useful for evaluating disease characteristics, yet they are more commonly used for predicting individual disease risk than for identifying factors at the population level. We offer a proof of concept applying random forest (RF) algorithms to Candida-positive hospital encounters in an electronic health record database of patients in the United States. Methods: Candida-positive encounters were extracted from the Cerner HealthFacts database; invasive infections were laboratory-positive sterile site Candida infections. Features included demographics, admission source, care setting, physician specialty, diagnostic and procedure codes, and medications received before the first positive Candida culture. We used RF to assess risk factors for 3 outcomes: any invasive candidiasis (IC) vs non-IC, within-species IC vs non-IC (eg, invasive C. glabrata vs noninvasive C. glabrata), and between-species IC (eg, invasive C. glabrata vs all other IC). Results: Fourteen of 169 (8%) variables were consistently identified as important features in the ML models. When evaluating within-species IC, for example, invasive C. glabrata vs non-invasive C. glabrata, we identified known features like central venous catheters, intensive care unit stay, and gastrointestinal operations. In contrast, important variables for invasive C. glabrata vs all other IC included renal disease and medications like diabetes therapeutics, cholesterol medications, and antiarrhythmics. Conclusions: Known and novel risk factors for IC were identified using ML, demonstrating the hypothesis-generating utility of this approach for infectious disease conditions about which less is known, specifically at the species level or for rarer diseases.
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INTRODUCTION: Co-sleeping with infants is a common practice across cultures, but pediatricians may struggle to engage in patient-centered conversations about infant sleep practices with non-native English- speaking families. Cultural humility is a critical skill to utilize when engaging in cross-cultural conversations. We designed a simulation for pediatric residents to counsel on safe sleep and enhance skills in self-perceived cultural humility and preparedness when caring for diverse patient populations. METHODS: We created a simulation for the second year and senior pediatric residents at a large academic institution focused on a co-sleeping parent and infant from the Burmese community. The Multidimensional Cultural Humility Scale (MCHS) was administered prior to and after the simulation. We also included additional questions regarding changes in knowledge and preparation in engaging in co-sleeping conversations across cultures. RESULTS: Fifty-seven residents participated. Overall, the mean score of the MCHS significantly increased after the simulation, indicating an increase in self-perceived cultural humility. All participants felt more prepared to have conversations about co-sleeping and to engage in difficult conversations with diverse patient populations, and all learned valuable skills to improve care for future patients. Comments regarding the scenario noted an appreciation for learning more about the Burmese population and understanding new approaches to safe sleep counseling. DISCUSSION: After this simulated scenario, residents reported increased self-perceived cultural humility, preparedness in counseling on co-sleeping, and skills to engage in difficult conversations with diverse patient populations. Topics such as cultural humility can be incorporated into simulation-based medical education to help improve the care of diverse patient populations.
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BACKGROUND: Preterm infants are at risk for hypothermia in the delivery room (DR). Hypothermia and community hospital delivery are factors associated with increased morbidities and mortality in preterm infants. Community hospital providers have less experience with preterm deliveries and thermoregulation methods in the DR. METHODS: Community hospital DR providers in Indiana completed a cognitive test evaluating preterm infant DR management. A simulation-based team assessment was evaluated by using a scoring tool. After debriefing, the simulation performance was repeated and rescored. Afterward, providers completed a cognitive knowledge posttest. Eleven to eighteen months later, sites were revisited with cognitive knowledge and team simulated scenarios reassessed. RESULTS: Twenty-five community hospitals with >400 multidisciplinary providers participated in the initial study visit. Average pre- and posttest scores were 48.8% and 94.1% respectively (P value <.001). Participants performed an average of 22.8 of 36 scoring items during a simulated preterm delivery including 4.4 of 8 thermoregulation related actions. Performance immediately improved in a statistically significant manner during the repeat scenario. When sites were revisited, participants performed an average of 26.7 of 36 scoring items including 6.1 of 8 thermoregulation actions during a simulated preterm delivery a statistically significant (P <.001) improvement from the initial visit. CONCLUSIONS: Simulation education regarding preterm infant DR management improved community providers immediate knowledge and skills and also follow-up performance at â¼1 year. In simulation, providers performed thermoregulation maneuvers more often and efficiently, critical to resuscitation because delays in thermoregulation can significantly adversely affect outcomes.
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Salas de Parto , Educação Médica/métodos , Hospitais Comunitários , Recém-Nascido Prematuro , Obstetrícia/educação , Equipe de Assistência ao Paciente , Treinamento por Simulação/métodos , Feminino , Humanos , Recém-Nascido , Gravidez , Estudos RetrospectivosRESUMO
INTRODUCTION AND OBJECTIVES: Somatostatin receptors (SSTR) recently have been identified as potential targets for treatment of solid tumors. Furthermore, they have been shown to be of high relevance for tumor biology and prognosis in various types of cancer. However, there is a lack of clinical data for SSTR in bladder cancer (BC). Aim of this study was to determine the expression of all relevant somatostatin receptor subtypes in benign urothelium and tumor tissue of patients with muscle invasive BC. Furthermore, their potential role as prognostic factor for cancer-specific survival (CSS) and overall survival (OS) was evaluated. METHODS: The collective included BC and benign urothelium tissue of 103 patients (Median age 69; range 32-84, 79 male, 24 female) who underwent a radical cystectomy. A tissue microarray with subsequent immunohistochemical staining was used to assess membranous expression of SSTR1-5. Results were correlated to clinical and histopathological data as well as CSS and OS. RESULTS: Expressions of SSTR1-4 were significantly decreased in BC compared to benign urothelium (P < 0.002 each), whereas SSTR5 expression was increased (Pâ¯=â¯0.0017). Expression of SSTR1 was associated with organ-confined disease (≤pT2) (Pâ¯=â¯0.0477). No correlation between SSTR1-5 expression and N- and M-stage was observed. Univariate analyses showed a significantly longer CSS and OS in patients with high expression of SSTR3 (Pâ¯=â¯0.0316 and 0.0044). Multivariate analyses confirmed SSTR3 expression as independent marker of improved CSS and OS (Pâ¯=â¯0.0324 and 0.0076). CONCLUSIONS: The majority of somatostatin receptor subtypes exhibit decreased expression in BC compared to benign bladder tissue. Expression of SSTR3 is an indicator for favorable prognosis in patients with muscle-invasive BC. These results support preclinical investigations using somatostatin receptor analogues such as octreotide to influence BC growth.
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Receptores de Somatostatina/biossíntese , Neoplasias da Bexiga Urinária/metabolismo , Neoplasias da Bexiga Urinária/mortalidade , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Coortes , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Prognóstico , Taxa de Sobrevida , Neoplasias da Bexiga Urinária/patologiaRESUMO
An excellent physician must be aware of the countless issues that affect each patient's health. Many medical education programs expose students to a broad spectrum of disparate knowledge and hope they will integrate all the pieces into a coherent whole. The authors describe an explicit approach to integration used at Harvard Medical School since 2003 that aims to enhance students' learning in medical school and throughout their medical careers: the Mentored Clinical Casebook Project (MCCP). The MCCP is constructed on the premise that such integration does not occur suddenly but, rather, is an unending process. A first-year student is assigned to one clinician and follows one patient for one year. The student is expected to spend as much time with the patient as possible, in both clinical and nonclinical settings, seek help from the clinician, and consult other experts and sources to develop a complete picture of the patient's life. The student must produce a casebook that includes, but is not limited to, the patient's history; basic science, clinical, socioeconomic, and cultural issues; and self-reflection. The MCCP is intended to allow students to develop a deeper and more diverse understanding of what comprises a patient's health care life, to discern the patient as a person and the person as a patient. This educational project has been popular with students since its inception, providing them with a personal framework from which to address the needs of future patients and introducing them to how much they will continue to learn from their patients.
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Educação de Graduação em Medicina/métodos , Mentores , Assistência Centrada no Paciente , Avaliação de Programas e Projetos de Saúde , Faculdades de Medicina , Estudantes de Medicina/psicologia , Boston , Processos Grupais , Humanos , Relações Interpessoais , Aprendizagem , Relações Médico-Paciente , Desenvolvimento de ProgramasRESUMO
Reporter gene activity in enhancer trap lines is often implicitly assumed to mirror quite faithfully the endogenous expression of the "trapped" gene, even though there are numerous examples of enhancer trap infidelity. optomotor-blind (omb) is a 160 kb gene in which 16 independent P-element enhancer trap insertions of three different types have been mapped in a range of more than 60 kb. We have determined the expression pattern of these elements in wing, eye-antennal and leg imaginal discs as well as in the pupal tergites. We noted that one pGawB insertion (omb (P4) ) selectively failed to report parts of the omb pattern even though the missing pattern elements were apparent in all other 15 lines. We ruled out that omb (P4) was defective in the Gal4 promoter region or had inactivated genomic enhancers in the integration process. We propose that the Gal4 reporter gene in pGawB may be sensitive to orientation or promoter proximity effects.