Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 278
Filtrar
1.
BMC Med Educ ; 24(1): 1085, 2024 Oct 03.
Artículo en Inglés | MEDLINE | ID: mdl-39363299

RESUMEN

BACKGROUND: Coaching in academic medicine may help learners develop lifelong learning skills. Studies typically evaluate the impact on coachees and program outcomes. Limited information is available about educating faculty to integrate the role of coaching. We explored a faculty coach training program at an academic medical center in the southern region of the United States. METHODS: Twenty faculty members in the college of medicine completed the 34-h training program meeting alternate weeks from May to November 2021. We collected data from reflections during training, a post-training survey, and three post-training focus group discussions making this a qualitatively driven mixed methods research. We used a transcendental phenomenological approach for the qualitative analysis entailing deriving essential meaning of the participants' training experiences and perceptions about coaching. RESULTS: We identified 3 themes (1) perceptions, skills, and understanding of coaching, (2) perceived additional benefits from coach training, and (3) effective instructional practices to teach coaching. Under the first theme, participants expressed improved understanding about the process of coaching in academic medicine, noted the importance of listening to the whole person without judgment, questioning with curiosity, vulnerability, self-awareness, and reflection for building trust. Perceived additional benefits included personal development and illuminating discoveries. Sub-themes for effective instructional practices were learning community encompassing mindfulness, psychological safety, social cohesion, experiential and interactive learning, and suggestions. Faculty experienced internal transformation while learning coaching and felt they had the capacity to influence personal and professional development of learners and colleagues. The concepts reflection, awareness, growth, and relationship were threaded throughout the three themes. CONCLUSIONS: The training evoked self-awareness and opportunities for personal growth. The newly trained coaches expressed the beginning of an internal transformation to embody being a coach and demonstrated willingness to influence personal and professional development of learners and colleagues. Effective instructional practices to teach coaching included mindfulness practice, psychological safety, social cohesion, and experiential and interactive learning. Based on these findings, it may be summarized that in the process of training to be a coach, the faculty not only recognized the benefits of coaching for learners but also realized individual personal benefits.


Asunto(s)
Centros Médicos Académicos , Docentes Médicos , Tutoría , Humanos , Docentes Médicos/psicología , Femenino , Masculino , Investigación Cualitativa , Grupos Focales , Adulto , Actitud del Personal de Salud , Estados Unidos
2.
Langmuir ; 37(43): 12663-12672, 2021 Nov 02.
Artículo en Inglés | MEDLINE | ID: mdl-34666489

RESUMEN

In this work, atomic layer etching (ALE) of Si compounds using H2 or N2 plasma modification followed by fluorine radical exposure is discussed. It is shown that the H2 plasma modification process promotes the selective etching of SiN, SiC, and SiCO versus SiO2. The N2 plasma modification, on the other hand, enables the selective etching of SiC and SiCO versus SiN and SiO2. The origin of the etching selectivity between different Si compounds is investigated using a combination of in situ SE and FTIR supported by several ex situ analysis techniques. It is shown that the formation of a hydrogen-rich layer after plasma modification is essential to enable the ALE process. The hydrogen-rich layer can be formed due to ion and radicals of the modification plasma (H2 plasma modification) or be a result of the reconfiguration of hydrogen that is already present in the film (N2 plasma modification). The obtained insights are expected to further enhance the etching selectivity of Si compound ALE processes. Furthermore, it is anticipated that the process can be extended to many other compound materials such as Ti and Hf, as well as enable selective etching between their oxides, carbides, and nitrides.

3.
J Intern Med ; 289(5): 726-737, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-33253457

RESUMEN

BACKGROUND: Whilst the COVID-19 diagnostic test has a high false-negative rate, not everyone initially negative is re-tested. Michigan Medicine, a primary regional centre, provided an ideal setting for studying testing patterns during the first wave of the pandemic. OBJECTIVES: To identify the characteristics of patients who underwent repeated testing for COVID-19 and determine if repeated testing was associated with downstream outcomes amongst positive cases. METHODS: Characteristics, test results, and health outcomes for patients presenting for a COVID-19 diagnostic test were collected. We examined whether patient characteristics differed with repeated testing and estimated a false-negative rate for the test. We then studied repeated testing patterns in patients with severe COVID-19-related outcomes. RESULTS: Patient age, sex, body mass index, neighbourhood poverty levels, pre-existing type 2 diabetes, circulatory, kidney, and liver diseases, and cough, fever/chills, and pain symptoms 14 days prior to a first test were associated with repeated testing. Amongst patients with a positive result, age (OR: 1.17; 95% CI: (1.05, 1.34)) and pre-existing kidney diseases (OR: 2.26; 95% CI: (1.41, 3.68)) remained significant. Hospitalization (OR: 7.88; 95% CI: (5.15, 12.26)) and ICU-level care (OR: 6.93; 95% CI: (4.44, 10.92)) were associated with repeated testing. The estimated false-negative rate was 23.8% (95% CI: (19.5%, 28.5%)). CONCLUSIONS: Whilst most patients were tested once and received a negative result, a meaningful subset underwent multiple rounds of testing. These results shed light on testing patterns and have important implications for understanding the variation of repeated testing results within and between patients.


Asunto(s)
Prueba de Ácido Nucleico para COVID-19 , COVID-19 , Reacciones Falso Negativas , Unidades de Cuidados Intensivos/estadística & datos numéricos , SARS-CoV-2/aislamiento & purificación , Factores de Edad , COVID-19/diagnóstico , COVID-19/epidemiología , COVID-19/fisiopatología , COVID-19/terapia , Prueba de Ácido Nucleico para COVID-19/métodos , Prueba de Ácido Nucleico para COVID-19/normas , Prueba de Ácido Nucleico para COVID-19/estadística & datos numéricos , Comorbilidad , Errores Diagnósticos/prevención & control , Femenino , Hospitalización/estadística & datos numéricos , Humanos , Enfermedades Renales/epidemiología , Masculino , Michigan/epidemiología , Persona de Mediana Edad , Reportes Públicos de Datos en Atención de Salud , Índice de Severidad de la Enfermedad , Factores Socioeconómicos
9.
Sci Rep ; 7: 41175, 2017 01 30.
Artículo en Inglés | MEDLINE | ID: mdl-28134260

RESUMEN

Modulation of photoluminescence of atomically thin transition metal dichalcogenide two-dimensional materials is critical for their integration in optoelectronic and photonic device applications. By coupling with different plasmonic array geometries, we have shown that the photoluminescence intensity can be enhanced and quenched in comparison with pristine monolayer MoS2. The enhanced exciton emission intensity can be further tuned by varying the angle of polarized incident excitation. Through controlled variation of the structural parameters of the plasmonic array in our experiment, we demonstrate modulation of the photoluminescence intensity from nearly fourfold quenching to approximately threefold enhancement. Our data indicates that the plasmonic resonance couples to optical fields at both, excitation and emission bands, and increases the spontaneous emission rate in a double spacing plasmonic array structure as compared with an equal spacing array structure. Furthermore our experimental results are supported by numerical as well as full electromagnetic wave simulations. This study can facilitate the incorporation of plasmon-enhanced transition metal dichalcogenide structures in photodetector, sensor and light emitter applications.

10.
Nanoscale ; 8(29): 14203-12, 2016 Aug 07.
Artículo en Inglés | MEDLINE | ID: mdl-27387963

RESUMEN

In this work we explore the preparation of complex-shaped semiconductor nanostructures composed of different materials via a cationic exchange process in which the cations of the original semiconductor nanostructure are replaced by cations of different metals with preservation of the shape and the anionic framework of the nanocrystals. Utilizing this cation exchange method, we synthesized two new tetrapods for the first time: Cu2-xSe/Cu2-xS and PbSe/PbS, both prepared from CdSe/CdS tetrapods as 'templates'. We also fabricated near-infrared (NIR) photodetectors with a very simple architecture comprising a PbSe/PbS tetrapod layer between two Au electrodes on a glass substrate. When illuminated by a NIR laser, these devices are capable of achieving a responsivity of 11.9 A W(-1) without the use of ligand-exchange processes, thermal annealing or hybrid device architecture. Transient absorption spectroscopy was carried out on these PbSe/PbS tetrapods, the results of which suggest that the branched morphology contributes in part to device performance. Investigation of the charge dynamics of the PbSe/PbS tetrapods revealed an extremely long-lived exciton recombination lifetime of ∼17 ms, which can result in enhanced photoconductive gain. Overall, these heterostructured tetrapods showcase simultaneously the importance of nanoparticle shape, band structure, and surface chemistry in the attainment of NIR photodetection.

11.
Placenta ; 36(6): 699-703, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-25913709

RESUMEN

INTRODUCTION: Phthalates and bisphenol-a (BPA) are endocrine disrupting compounds with widespread exposure that have been linked to adverse birth outcomes and developmental effects. We hypothesized that these associations may be mediated in part through altered placental development and function consequent to exposure. To investigate this question, we examined associations between plasma biomarkers of angiogenesis and urinary biomarkers of exposure to phthalates and bisphenol-a (BPA) measured at repeated time points across pregnancy. METHODS: We utilized a nested case-control population of 130 mothers who delivered preterm and 352 who delivered term from a prospective birth cohort. Placental growth factor (PlGF) and soluble fms-like tyrosine kinase-1 (sFlt-1) were measured in plasma samples collected from up to four visits during pregnancy (median 10, 18, 26, and 35 weeks). Phthalate metabolites and BPA were measured in urine samples collected at the same visits as indices of exposure. RESULTS: In linear mixed effects models adjusted for urine dilution and gestational age at sample collection, oxidized di-2-ethylhexyl phthalate (DEHP) metabolites were associated with decreases in PlGF as well as increases in the sFlt-1 to PlGF ratio. These results were slightly attenuated in fully adjusted models. Other phthalate metabolites did not show consistent relationships with either sFlt-1 or PlGF. BPA, however, was associated with increased sFlt-1 as well as the sFlt-1 to PlGF ratio in both crude and adjusted models. DISCUSSION: We observed associations between urinary DEHP metabolites and BPA and biomarkers of angiogenesis during pregnancy that may be indicative of disrupted placental development and/or function during gestation.


Asunto(s)
Compuestos de Bencidrilo/orina , Fenoles/orina , Ácidos Ftálicos/orina , Proteínas Gestacionales/sangre , Receptor 1 de Factores de Crecimiento Endotelial Vascular/sangre , Biomarcadores/sangre , Estudios de Casos y Controles , Femenino , Humanos , Factor de Crecimiento Placentario , Embarazo
12.
Diabet Med ; 32(9): 1193-200, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-25443798

RESUMEN

AIMS: To examine the associations between endogenous sex steroid hormones (oestradiol, testosterone and sex hormone-binding globulin) with diabetes risk in a South-Asian population living in the USA. METHODS: We used data from the Metabolic Syndrome and Atherosclerosis in South-Asians Living in America pilot study. The analytical sample included 60 women and 45 men of Asian Indian origin living in the San Francisco Bay Area, who were free from diabetes and cardiovascular disease and did not use exogenous sex steroids. Sex steroid hormone levels were assessed by validated conventional radioimmunoassays, and visceral and hepatic adiposity were assessed by computed tomography. We used multivariable regression to examine the association between endogenous sex steroid hormone levels (log-transformed) and fasting glucose and 2-h glucose levels in a series of sex-stratified models adjusted for age, waist circumference, visceral and hepatic adiposity, and insulin resistance. RESULTS: In age-adjusted models, lower levels of sex hormone-binding globulin (ß = -0.18, 95% CI -0.30, -0.06) and higher levels of free testosterone (ß = 0.14, 95% CI 0.02, 0.26) were associated with elevated fasting glucose levels in South-Asian women, whereas lower levels of sex hormone-binding globulin (ß = -0.14, 95% CI -0.26, -0.02) and lower levels of total testosterone (ß = -0.12, 95% CI -0.24, 0.00) were associated with elevated fasting glucose levels in South-Asian men. Adjustment for waist circumference, visceral adiposity and insulin resistance attenuated most of these associations, while adjustment for hepatic adiposity strengthened some of the observed associations. Similar results were found for 2-h glucose levels. CONCLUSIONS: Results were consistent with previous research, which suggests that endogenous sex steroid hormones are a risk factor for diabetes across multiple race/ethnic groups. Additional studies are needed to determine whether visceral fat is a mediator or confounder of associations between sex steroid hormone and glucose levels.


Asunto(s)
Glucemia/metabolismo , Estradiol/metabolismo , Globulina de Unión a Hormona Sexual/metabolismo , Testosterona/metabolismo , Anciano , Anciano de 80 o más Años , Asiático/etnología , Estudios Transversales , Femenino , Humanos , Masculino , Persona de Mediana Edad , Proyectos Piloto , San Francisco/epidemiología , Distribución por Sexo
13.
Oncogene ; 34(8): 1064-72, 2015 Feb 19.
Artículo en Inglés | MEDLINE | ID: mdl-24632607

RESUMEN

Glioblastomas (GBM) are highly radioresistant and lethal brain tumors. Ionizing radiation (IR)-induced DNA double-strand breaks (DSBs) are a risk factor for the development of GBM. In this study, we systematically examined the contribution of IR-induced DSBs to GBM development using transgenic mouse models harboring brain-targeted deletions of key tumor suppressors frequently lost in GBM, namely Ink4a, Ink4b, Arf and/or PTEN. Using low linear energy transfer (LET) X-rays to generate simple breaks or high LET HZE particles (Fe ions) to generate complex breaks, we found that DSBs induce high-grade gliomas in these mice which, otherwise, do not develop gliomas spontaneously. Loss of Ink4a and Arf was sufficient to trigger IR-induced glioma development but additional loss of Ink4b significantly increased tumor incidence. We analyzed IR-induced tumors for copy number alterations to identify oncogenic changes that were generated and selected for as a consequence of stochastic DSB events. We found Met amplification to be the most significant oncogenic event in these radiation-induced gliomas. Importantly, Met activation resulted in the expression of Sox2, a GBM cancer stem cell marker, and was obligatory for tumor formation. In sum, these results indicate that radiation-induced DSBs cooperate with loss of Ink4 and Arf tumor suppressors to generate high-grade gliomas that are commonly driven by Met amplification and activation.


Asunto(s)
Neoplasias Encefálicas/genética , Inhibidor p15 de las Quinasas Dependientes de la Ciclina/genética , Inhibidor p16 de la Quinasa Dependiente de Ciclina/genética , Roturas del ADN de Doble Cadena , Glioblastoma/genética , Proteínas Proto-Oncogénicas c-met/genética , Animales , Roturas del ADN de Doble Cadena/efectos de la radiación , Amplificación de Genes , Eliminación de Gen , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Ratones Desnudos , Radiación Ionizante
15.
J Environ Biol ; 35(3): 577-88, 2014 May.
Artículo en Inglés | MEDLINE | ID: mdl-24813016

RESUMEN

Modelling system dynamics in a hyper-eutrophic lake is quite complex especially with a constant influx of detergents and sewage material which continually changes the state variables and interferes with the assessment of the chemical rhythm occurring in polluted conditions as compared to unpolluted systems. In this paper, a carbon and nutrient mass balance model for predicting system dynamics in a complex environment was studied. Studies were conducted at Ranchi lake to understand the altered environmental dynamics in hyper-eutrophic conditions, and its impact on the plankton community. The lake was monitored regularly for five years (2007 - 2011) and the data collected on the carbon flux, nitrates, phosphates and silicates was used to design a mass balance model for evaluating and predicting the system. The model was then used to correlate the chemical rhythm with that of the phytoplankton dynamics and diversity. Nitrates and phosphates were not limiting (mean nitrate and phosphate concentrations were 1.74 and 0.83 mgl⁻¹ respectively). Free carbon dioxide was found to control the system and, interacting with other parameters determined the diversity and dynamics of the plankton community. N/P ratio determined which group of phytoplankton dominated the community, above 5 it favoured the growth of chlorophyceae while below 5 cyanobacteria dominates. TOC/TIC ratio determined the abundance. The overall system was controlled by the availability of free carbon dioxide which served as a limiting factor.


Asunto(s)
Carbono/química , Lagos , Modelos Biológicos , Fitoplancton/clasificación , Carbono/metabolismo , Quimiocina CCL11 , Monitoreo del Ambiente , Dinámica Poblacional , Factores de Tiempo
18.
Indian Pediatr ; 50(7): 707, 2013 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-23942441

RESUMEN

Extensive use of antibiotics have resulted in development of resistance among most commonly used drugs in community acquired urinary tract infection (UTI). This study was conducted to identify the resistance pattern in community acquired UTI .We collected urine for routine examination and culture from suprapubic urine in all the cases to avoid any contamination. E. Coli was the most common organism identified. Among oral antibiotics, there was high degree of resistance to penicillin group and cephalosporin groups. Among parentral antibiotics, all the cephalosporins were variably resistant except cephaperazone-salbactum.


Asunto(s)
Antibacterianos/farmacología , Infecciones Comunitarias Adquiridas/microbiología , Infecciones por Enterobacteriaceae/microbiología , Infecciones Urinarias/microbiología , Preescolar , Estudios de Cohortes , Farmacorresistencia Bacteriana , Enterobacteriaceae/efectos de los fármacos , Humanos , India , Lactante , Pruebas de Sensibilidad Microbiana
20.
J Maxillofac Oral Surg ; 12(1): 113-6, 2013 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-24431825

RESUMEN

One of the most commonly used local anesthetic techniques in dentistry is the Fischer's technique for the inferior alveolar nerve block. Incidentally this technique also suffers the maximum failure rate of approximately 35-45%. We studied a method of inferior alveolar nerve block by injecting a local anesthetic solution into the pterygomandibular space by arching and changing the approach angle of the conventional technique and estimated its efficacy. The needle after the initial insertion is arched and inserted in a manner that it approaches the medial surface of the ramus at an angle almost perpendicular to it. The technique was applied to 100 patients for mandibular molar extraction and the anesthetic effects were assessed. A success rate of 98% was obtained.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA