This work reports the Raman scattering surface and in-depth resolved analysis of Cu-poor Cu(In,Ga)Se2 (CIGS) grown on polyimide substrates. In order to study the effect of Na on the formation and ...microstructure of the CIGS and the corresponding Cu-poor ordered vacancy compound (OVC) phases, a NaF precursor layer with different thicknesses was deposited on the Mo-coated substrates before growing of the samples. The Raman spectroscopy data are correlated with the analysis of the samples by Auger electron spectroscopy and scanning electron microscopy. These data corroborate the significant role of Na on the inhibition of Ga-In interdiffusion and on the formation of the MoSe2 interfacial phase at the back region of the layers. Presence of Na also leads to an enhancement in the formation of the chalcopyrite CIGS phase and a decrease in the occurrence of the dominant OVC phase at the surface region. This study confirms the strong dependence of the microstructure and phase distribution in CIGS absorber layers on the Na available during their growth.
9-4-(18)Ffluoro-3-(hydroxymethyl)butylguanine ((18)FFHBG) has been used as a reporter probe to image expression of herpes simplex virus type-1 thymidine kinase (HSV1-tk) reporter gene in living ...animals. Our aim was to study the kinetics, biodistribution, stability, dosimetry, and safety of (18)FFHBG in healthy human volunteers, preparatory to imaging patients undergoing HSV1-tk gene therapy.
(18)FFHBG was synthesized with a specific activity of 37,000--444,000 GBq/mmol and a radiochemical purity > 99%. Ten healthy volunteers consented to participate in the study. A transmission scan was obtained before bolus injection of 70.3--229.4 MBq (18)FFHBG into a hand vein, followed by dynamic PET imaging with 4 consecutive emission scans. Warmed hand-vein blood was withdrawn at various times after injection for blood time--activity measurements. Electrocardiography, blood pressure, and blood and urine pharmacologic parameters were measured before and after injection of the (18)FFHBG tracer (n = 5). The stability of (18)FFHBG in the urine was analyzed. Attenuation-corrected images were reconstructed using the ordered-subsets expectation maximization algorithm. Image region-of-interest time-activity data were used with the MIRD program to estimate absorbed radiation dosages.
(18)FFHBG had rapid blood clearance; only 8.42% +/- 4.76% (mean +/- SD) of the peak blood activity remained at approximately 30 min. The average ratio of plasma activity to whole-blood activity during the study was 0.91 +/- 0.04. Penetration of (18)FFHBG across the blood-brain barrier was not observed. The primary routes of clearance were renal and hepatobiliary. High activities were observed in the bladder, gut, liver, and kidneys, but <0.0002% of the injected dose per gram was observed in other tissues. In the urine, 83% of activity 180 min after injection was stable (18)FFHBG. Blood and urine pharmacologic parameters did not change significantly after injection of the (18)FFHBG tracer. The bladder absorbed the highest radiation dose.
(18)FFHBG has the desirable in vivo characteristics of stability, rapid blood clearance, low background signal, biosafety, and acceptable radiation dosimetry in humans. This study forms the foundation for using (18)FFHBG in applications to monitor HSV1-tk reporter gene expression.
Aims The aims of this observational study were to identify the special needs of children with Type 1 diabetes in schools from the parents’ point of view and the difficulties experienced with full ...integration, and to define a series of interventions which may improve the situation.
Methods Parents of children aged 3–18 years with Type 1 diabetes were eligible. Those who agreed to participate completed a self‐reporting questionnaire which determined the effects of the disease on children, parents and school personnel, and addressed aspects including children's integration, glycaemic control, insulin administration, meals, sports, trips and attitudes of teachers and school colleagues to their disease.
Results A total of 499 questionnaires were completed and validated. Median age of children was 11.5 years (95% CI 7.8–15.2). Only 34% of parents believed that teachers could recognize the symptoms of a mild hypoglycaemic episode. Seventeen per cent of parents experienced problems at their schools when they informed staff about their children's disease, 5% were finally not accepted and 8% were forced to change school. In some cases, they had to modify glucose monitoring (9%) and treatment administration (16%) because of a lack of cooperation from the school.
Conclusions Training sessions on Type 1 diabetes, an increase in the number of nurses, better availability of resources from diabetic associations to schools and improved communication between school personnel and parents were identified as key factors that may improve the full integration of the diabetic child in this setting.
Context. QSO B0218+357 is a gravitationally lensed blazar located at a redshift of 0.944. The gravitational lensing splits the emitted radiation into two components that are spatially ...indistinguishable by gamma-ray instruments, but separated by a 10–12 day delay. In July 2014, QSO B0218+357 experienced a violent flare observed by the Fermi-LAT and followed by the MAGIC telescopes. Aims. The spectral energy distribution of QSO B0218+357 can give information on the energetics of z ~ 1 very high energy gamma-ray sources. Moreover the gamma-ray emission can also be used as a probe of the extragalactic background light at z ~ 1. Methods. MAGIC performed observations of QSO B0218+357 during the expected arrival time of the delayed component of the emission. The MAGIC and Fermi-LAT observations were accompanied by quasi-simultaneous optical data from the KVA telescope and X-ray observations by Swift-XRT. We construct a multiwavelength spectral energy distribution of QSO B0218+357 and use it to model the source. The GeV and sub-TeV data obtained by Fermi-LAT and MAGIC are used to set constraints on the extragalactic background light. Results. Very high energy gamma-ray emission was detected from the direction of QSO B0218+357 by the MAGIC telescopes during the expected time of arrival of the trailing component of the flare, making it the farthest very high energy gamma-ray source detected to date. The observed emission spans the energy range from 65 to 175 GeV. The combined MAGIC and Fermi-LAT spectral energy distribution of QSO B0218+357 is consistent with current extragalactic background light models. The broadband emission can be modeled in the framework of a two-zone external Compton scenario, where the GeV emission comes from an emission region in the jet, located outside the broad line region.
RESUMEN: Las restricciones por la pandemia del COVID-19 supusieron la transición abrupta a una enseñanza online tanto del contenido teórico como práctico y de la evaluación final de las asignaturas ...que imparte el departamento en varias titulaciones. En previsión de que el siguiente curso académico 2020-21 se vería totalmente afectado, se desarrollaron una serie de materiales didácticos propios, como la elaboración de guiones de teoría y práctica que incorporaron imágenes de modelos anatómicos, prosecciones, anatomía radiológica y anatomía ecográfica. La percepción de esta innovación fue evaluada por los estudiantes a través de una encuesta en línea y sus respuestas mediante una escala tipo Likert. Participaron 346 estudiantes de las titulaciones de Fisioterapia (n= 66), Medicina (n= 169), Podología (n= 44) y Terapia Ocupacional (n= 67). Las puntuaciones medias más altas correspondieron a los estudiantes de Podología y Terapia Ocupacional, ambas presentaron diferencias significativas con los otros tres subgrupos de alumnos (p<.0001). El puntaje promedio más bajo correspondió a los estudiantes de Medicina de segundo año académico que presentó significancia con los otros cuatro subgrupos de estudiantes (p<.0001). Se analizaron las carencias del sistema educativo en la Universidad Complutense de Madrid reveladas por la pandemia del Covid19. Esta crisis ha puesto de manifiesto la necesidad de que los educadores médicos en general y los anatomistas en particular estén capacitados en el uso de la tecnología disponible y en la creación de sus propios materiales didácticos multimedia.
Repeated, noninvasive imaging of reporter gene expression is emerging as a valuable tool for monitoring the expression of genes in animals and humans. Monitoring of organ/cell transplantation in ...living animals and humans, and the assessment of environmental, behavioral, and pharmacologic modulation of gene expression in transgenic animals should soon be possible. The earliest clinical application is likely to be monitoring human gene therapy in tumors transduced with the herpes simplex virus type 1 thymidine kinase (HSV1-tk) suicide gene. Several candidate assays for imaging reporter gene expression have been studied, utilizing cytosine deaminase (CD), HSV1-tk, and dopamine 2 receptor (D2R) as reporter genes. For the HSV1-tk reporter gene, both uracil nucleoside derivatives (e.g., 5-iodo-2′-fluoro-2′-deoxy-1-β-
d-arabinofuranosyl-5-iodouracil FIAU labeled with
124I,
131I ) and acycloguanosine derivatives {e.g., 8-
18Ffluoro-9-2-hydroxy-1-(hydroxymethyl)ethoxymethylguanine (8-
18F-fluoroganciclovir) (
18FFGCV), 9-(3-
18Ffluoro-1-hydroxy-2-propoxy)methylguanine (
18FFHPG)} have been investigated as reporter probes. For the D2R reporter gene, a derivative of spiperone {3-(2′-
18F-Fluoroethyl)spiperone (
18FFESP)} has been used with positron emission tomography (PET) imaging. In this review, the principles and specific assays for imaging reporter gene expression are presented and discussed. Specific examples utilizing adenoviral-mediated delivery of a reporter gene as well as tumors expressing reporter genes are discussed.
ABSTRACT
We present a measurement of the extragalactic background light (EBL) based on a joint likelihood analysis of 32 gamma-ray spectra for 12 blazars in the redshift range z = 0.03–0.944, ...obtained by the MAGIC telescopes and Fermi-LAT. The EBL is the part of the diffuse extragalactic radiation spanning the ultraviolet, visible, and infrared bands. Major contributors to the EBL are the light emitted by stars through the history of the Universe, and the fraction of it that was absorbed by dust in galaxies and re-emitted at longer wavelengths.
The EBL can be studied indirectly through its effect on very high energy photons that are emitted by cosmic sources and absorbed via γγ interactions during their propagation across cosmological distances. We obtain estimates of the EBL density in good agreement with state-of-the-art models of the EBL production and evolution. The 1σ upper bounds, including systematic uncertainties, are between 13 per cent and 23 per cent above the nominal EBL density in the models. No anomaly in the expected transparency of the Universe to gamma-rays is observed in any range of optical depth. We also perform a wavelength-resolved EBL determination, which results in a hint of an excess of EBL in the 0.18–0.62 $\mu\mathrm{ m}$ range relative to the studied models, yet compatible with them within systematics.
The atmospheric Cherenkov gamma-ray telescope MAGIC, designed for a low-energy threshold, has detected very-high-energy gamma rays from a giant flare of the distant Quasi-Stellar Radio Source (in ...short: radio quasar) 3C 279, at a distance of more than 5 billion light-years (a redshift of 0.536). No quasar has been observed previously in very-high-energy gamma radiation, and this is also the most distant object detected emitting gamma rays above 50 gigaelectron volts. Because high-energy gamma rays may be stopped by interacting with the diffuse background light in the universe, the observations by MAGIC imply a low amount for such light, consistent with that known from galaxy counts.
Methods to repeatedly, non-invasively, and quantitatively image gene expression in living animals are rapidly emerging and should fundamentally change studies of gene expression in vivo. We ...previously developed assays utilizing positron emission tomography (PET) to image reporter gene expression. In this paper we: (1) describe a new bi-directional, tetracycline-inducible system that can be used to pharmacologically induce target gene expression and to quantitatively image induced expression by using a PET reporter gene; (2) demonstrate the potential of this system in transient and stable cell transfection assays; and (3) demonstrate the ability to repetitively and quantitatively image tetracycline and tetracycline analog induction of gene expression in living animals. We utilize the dopamine type-2 receptor (D(2)R) and the mutant herpes-simplex virus type 1 thymidine kinase (HSV1-sr39tk) reporter genes to validate this system. We utilize microPET technology to show that quantitative tomographic imaging of gene induction is possible. We find a high correlation (r(2) = 0.98) between 'target' and reporter gene expression. This work establishes a new technique for imaging time-dependent variation of gene expression both from vectors with inducible promoters and in transgenic animals in which pharmacologic induction of gene expression must be monitored. These techniques may be applied both in gene therapy and for the study of gene expression in transgenic animals.
Biodistribution, magnitude and duration of a therapeutic transgene's expression may be assessed by linking it to the expression of a positron emission tomography (PET) reporter gene (PRG) and then ...imaging the PRG's expression by a PET reporter probe (PRP) in living animals. We validate the simple approach of co-administering two distinct but otherwise identical adenoviruses, one expressing a therapeutic transgene and the other expressing the PRG, to track the therapeutic gene's expression. Two PET reporter genes, a mutant herpes simplex virus type 1 thymidine kinase (HSV1-sr39tk) and dopamine-2 receptor (D(2)R), each regulated by the same cytomegalovirus (CMV) promoter, have been inserted into separate adenoviral vectors (Ad). We demonstrate that cells co-infected with equivalent titers of Ad-CMV-HSV1-sr39tk and Ad-CMV-D(2)R express both reporter genes with good correlation (r(2) = 0.93). Similarly, a high correlation (r(2) = 0.97) was observed between the expression of both PRGs in the livers of mice co-infected via tail-vein injection with equivalent titers of these two adenoviruses. Finally, microPET imaging of HSV1-sr39tk and D(2)R expression with 9-(4-(18)Ffluoro-3-hydroxymethylbutyl) guanine ((18)FFHBG) and 3-(2-(18)Ffluoroethyl)spiperone ((18)FFESP), utilizing several adenovirus-mediated delivery routes, illustrates the feasibility of evaluating relative levels of transgene expression in living animals, using this approach.
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