RESUMO
Colloidal nanorod heterostructures consisting of multiple quantum dots within a nanorod (n-DNRs, where n is the number of quantum dots within a nanorod) are synthesized with alternating segments of CdSe "dot" and CdS "rod" via solution heteroepitaxy. The reaction temperature, time dependent ripening, and asymmetry of the wurtzite lattice and the resulting anisotropy of surface ligand steric hindrance are exploited to vary the morphology of the growing quantum dot segments. The alternating CdSe and CdS growth steps can be easily repeated to increment the dot number in unidirectional or bidirectional growth regimes. As an initial exploration of electron occupation effects on their optical properties, asymmetric 2-DNRs consisting of two dots of different lengths and diameters are synthesized and are shown to exhibit a change in color and an unusual photoluminescence quantum yield increase upon photochemical doping.
RESUMO
Despite the substantial body of investigative work describing the Coronavirus Disease 2019 (COVID-19) pandemic, its impact on neonates and infants remains less well characterized. Here, we review the data on epidemiology of COVID-19 in this population. Widespread use of universal testing for SARS-CoV-2 among pregnant persons presenting for delivery complicates interpretation of the risks of perinatal exposure. While many neonates and infants with COVID-19 are well-appearing or have only mild signs of illness, factors such as preterm birth, low birth weight, and medical comorbidities increase the risk of severe infection. We highlight potential protective maternal factors, summarize treatment options and discuss vaccine development. Higher quality data are needed to better inform our understanding of COVID-19 in neonates and infants.
Assuntos
COVID-19 , Transmissão Vertical de Doenças Infecciosas , Complicações Infecciosas na Gravidez , SARS-CoV-2 , Humanos , COVID-19/epidemiologia , COVID-19/prevenção & controle , COVID-19/terapia , Recém-Nascido , Gravidez , Feminino , Complicações Infecciosas na Gravidez/epidemiologia , Transmissão Vertical de Doenças Infecciosas/prevenção & controle , Lactente , Fatores de Risco , Vacinas contra COVID-19 , Nascimento Prematuro/epidemiologiaRESUMO
We report on the fabrication and utilization of a robust high-temperature (>300 °C), adjustable-path-length, vacuum-tolerant, configurable, in situ optical probe, which interfaces with widely used chemical glassware via a 14/20 ground glass joint. This probe allows for high-speed reaction monitoring of colloidal semiconductor nanocrystal solutions at temperatures that were previously inaccessible. We demonstrate this capability by monitoring the hot-injection synthesis of CdSe quantum dots via UV-Vis absorption spectroscopy at 380 °C with a time resolution of â¼10 ms, with the primary limitation being the acquisition and data saving rate of the commercial spectrometer used. We further demonstrate that this probe can also be used for in situ photoluminescence measurements. This system is generally applicable to harsh solution environments where optical monitoring of reaction progress is desirable and/or necessary.
RESUMO
Myocarditis is typically caused by viral infections, but most cases are thought to be subclinical. Echocardiography is often used for initial assessment of myocarditis patients but is poor at detecting subtle changes in cardiac dysfunction. Cardiac strain, such as global longitudinal strain (GLS) and global circumferential strain (GCS), represents an increasingly used set of measurements which can detect these subtle changes. Using a murine model of coxsackievirus B3 myocarditis, we characterized functional changes in the heart using echocardiography during myocarditis and by sex. We found that 2D GLS, 4D mode, and 4D strains detected a significant reduction in ejection fraction and GLS during myocarditis compared to baseline and in males compared to females. Furthermore, worse GLS correlated to increased levels of CD45+, CD11b+, and CD3+ immune cells. Our findings closely resemble published reports of GLS in patients with myocarditis indicating the usefulness of this animal model for translational studies of myocarditis.
RESUMO
PROSPER is an international Phase III trial demonstrating the beneficial role of enzalutamide, an androgen receptor antagonist, in prolonging metastasis-free survival in men with nonmetastatic castration-resistant prostate cancer. The trial showed that the median metastasis-free survival was 21.9 months longer for those treated with enzalutamide (36.6 months) compared to those treated with placebo (14.7 months). Enzalutamide also showed prolonged time to PSA progression, PSA response, and time to initiating additional antineoplastic therapy although overall survival is not yet reached. Enzalutamide is the second antiandrogen (next to apalutamide) that has gained the United States Food and Drug Administration (US FDA) label indication for use in the setting of nonmetastatic castration-resistant prostate cancer.