Nominally forbidden transitions in the interband optical spectrum of quantum dots

We calculate the excitonic optical absorption spectra of (In,Ga)As/GaAs self-assembled quantum dots by adopting an atomistic pseudopotential approach to the single-particle problem followed by a configuration-interaction approach to the many-body problem. We find three types of allowed transitions that would be naively expected to be forbidden. (i) Transitions that are parity forbidden in simple effective mass models with infinite confining wells (e.g. 1S-2S, 1P-2P) but are possible by finite band-offsets and orbital-mixing effects; (ii) light-hole--to--conduction transitions, enabled by the confinement of light-hole states; and (iii) transitions that show and enhanced intensity due to electron-hole configuration mixing with allowed transitions. We compare these predictions with results of 8-band k.p calculations as well as recent spectroscopic data. Transitions in (i) and (ii) explain recently observed satellites of the allowed P-P transitions.Comment: Version published in Phys. Rev.

Ajuste de cono con ajuste de agua: cambios en la razón agua/cemento, que alteran las resistencias de un hormigón premezclado

Tesis (Ingeniero Constructor)En el proceso industrializado de producción de un hormigón, llamado Hormigón Premezclado (H.P.), existen múltiples variables que alteran los resultados finales de éste o mejor dicho, que afectan las resistencias de un hormigón. La importancia de ir disminuyendo la variabilidad de resultados de un H.P., se ve reflejado tanto para bajar costos de producción hasta implicancias medio ambientales en la disminución de utilización de recursos que impactan nuestro sistema. Las variables pueden estar en diferentes etapas del proceso de producción, es por eso que la presente investigación se enfocará en un punto específico del proceso, el cual es “Ajuste de Cono en Planta” localizado en la etapa de mezclado de producción de una planta de H.P. Para llevar a cabo esta investigación se plantea un trabajo en terreno, en una planta de hormigones premezclados, con una serie de tareas tales como; mediciones de tiempo y cantidad de adición de agua, resistencias a la compresión. Con el fin de abordar puntos como la baja de resistencias de los hormigones y variabilidad entre estos, necesarios para determinar los aspectos relevantes en proceso de ajuste de cono en planta. Como resultado de la investigación se presenta una propuesta de trabajo para el puente de ajuste de cono (instructivo de trabajo), con el fin regular la participación de los operadores mixer y las razones agua / cemento dentro de parámetros que disminuyan la variabilidad de las resistencias.Within the industrialized process of concrete productions, also called Premix-Concrete (P.C), there are a series of variables that may affect the final outcomes of it or that affect the resistance of concrete itself. The importance of decreasing the board possibilities of outcomes of a P.C is reflected both in lower production costs and the environmental implications in reducing the use of resources that may impact our eco-system. Such variables can be found in different stages of the production process, that is why this piece of research aims to an specific area in the process, which is called “Adjusting Cone Plant”. That it is located in the mixing stage production of a P.C plant. To develop this investigation, a field work in an premixed concrete plan is proposed, with a serie of tasks such as: time measurement and the amount of water that is added throughout the process, and compressive strengths are also considered as relevant for the purpose of this investigation. The aim of this is to address issues Such as low resistance of concrete and the variability among them which are necessaries to determine the relevant aspects in the process of adjusting the cone plant. As a result of this research, a work proposal is presented in order to tackle the issues that may occur in the bridge adjusting cone (instructive of work), with the main aim of regulating the participation of mixer operators and the amount of water and cement used on the process within the parameters that could reduce the variability of concrete resistance

Education on the use of Code Lavender for ICU Nurses to Decrease Turnover and Increase Engagement

Education of Code Lavender for Nurses working in the Intensive Care Unit at Parker Adventist Hospital, Parker Colorado Purpose: Now more than ever healthcare leaders need to lead with a healing touch and help provide support for development of culture of caring. Nurses provide invaluable emotional support, as they understand the complexities and implications of an illness and its impact on not only a diagnosis or treatment plan, but on the whole person. Nurses’ knowledge of illness combined with exceptional people skills provide comfort and stability during times often filled with pain and uncertainty for patients and their families. In the most recent months with the global pandemic of COVID-19 nursing has been tested beyond comprehension. The purpose of this quality improvement initiative is to educate nurses working in the ICU at Parker Adventist Hospital on use of Code Lavender. Description/Objectives: The goal is to provide education on Code Lavender as a coordinated, immediate response from a multi-disciplinary team to provide administrative, emotional, and spiritual support to ICU nurses in need of additional support in order to increase engagement and decrease nursing turnover. By addressing the real-time needs of nurses, the desired outcome is that nurses are more satisfied, engage, and likely to remain in their position. Objectives: Increase nurse satisfaction Decrease RN Turnover in ICU Decrease time to fill for open ICU, RN position

Amphibia, Anura, Strabomantidae, <i>Pristimantis permixtus</i> Lynch, Ruiz-Carranza, and Ardila-Robayo, 1994: Distribution extension, Valle del Cauca, Colombia

Pristimantis permixtus is a moderate sized frog tipically of upper cloud forests and sub-páramo areas. Herewe provide the second record and southernmost of P. permixtus in the Occidental Cordillera in the department of Valle delCauca, Vereda Chicoral, municipality of La Cumbre, Colombia

In vitro bioaccessibility and antioxidant activity of coffee silverskin polyphenolic extract and characterization of bioactive compounds using UHPLC-Q-Orbitrap HRMS

Coffee silverskin (CS), the main by-product in the coffee industry, contains a vast number of human health-related compounds, which may justify its exploitation as a functional food ingredient. This study aimed to provide a comprehensive analysis of the polyphenolic and alkaloid profile through UHPLC-Q-Orbitrap HRMS analysis. The bioaccessibility of total phenolic compounds and changes in the antioxidant activity during an in vitro gastrointestinal digestion were also evaluated through spectrophotometric tests (TPC by Folin-Ciocalteu, ABTS, DPPH, and FRAP), to elucidate their effcacy for future applications in the nutraceutical industry. Caffeoylquinic and feruloylquinic acids were the most representative polyphenols, with a mean concentration of 5.93 and 4.25 mg/g, respectively. Results showed a high content of caffeine in the analyzed CS extracts, with a mean value of 31.2 mg/g, meaning a two-fold increase when compared to coffee brews. Our findings highlighted that both the bioaccessibility and antioxidant activity of CS polyphenols significantly increased in each in vitro gastrointestinal digestion stage. In addition, the colon stage might constitute the main biological site of action of these antioxidant compounds. These results suggest that in vivo, the dietary polyphenols from CS might be metabolized by human colonic microflora, generating metabolites with a greater antioxidant activity, increasing their well-known beneficial effects

Red wine consumption and cardiovascular health

Wine is a popular alcoholic beverage that has been consumed for hundreds of years. Benefits from moderate alcohol consumption have been widely supported by the scientific literature and, in this line, red wine intake has been related to a lesser risk for coronary heart disease (CHD). Experimental studies and meta-analyses have mainly attributed this outcome to the presence in red wine of a great variety of polyphenolic compounds such as resveratrol, catechin, epicatechin, quercetin, and anthocyanin. Resveratrol is considered the most effective wine compound with respect to the prevention of CHD because of its antioxidant properties. The mechanisms responsible for its putative cardioprotective effects would include changes in lipid profiles, reduction of insulin resistance, and decrease in oxidative stress of low-density lipoprotein cholesterol (LDL-C). The aim of this review is to summarize the accumulated evidence correlating moderate red wine consumption with prevention of CHD by focusing on the different mechanisms underlying this relationship. Furthermore, the chemistry of wine as well as chemical factors that influence the composition of the bioactive components of red wine are also discussed

Occurrence and exposure assessment of mycotoxins in ready-to-eat tree nut products through ultra-high performance liquid chromatography coupled with high resolution q-orbitrap mass spectrometry

Tree nuts have become popular snacks due to their attributed benefits in the health state. Nevertheless, their susceptibility to fungal contamination lead to the occurrence of potentially dangerous mycotoxins. Hence, the aim of this work was to evaluate the presence of mycotoxins in ready-to-eat almonds, walnuts, and pistachios from Italian markets. The most relevant mycotoxin found in almonds was α-zearalanol in 18% of samples (n = 17) ranging from 3.70 to 4.54 µg/kg. Walnut samples showed frequent contamination with alternariol, present in 53% of samples (n = 22) at levels from 0.29 to 1.65 µg/kg. Pistachios (n = 15) were the most contaminated commodity, with β-zearalenol as the most prevalent toxin present in 59% of samples ranging from 0.96 to 8.60 µg/kg. In the worst-case scenario, the exposure to zearalenone-derived forms accounted for 15.6% of the tolerable daily intake, whereas it meant 12.4% and 21.2% of the threshold of toxicological concern for alternariol and alternariol monomethyl-ether, respectively. The results highlighted the extensive presence of Alternaria toxins and zearalenone-derived forms, scarcely studied in ready-to-eat tree nut products, highlighting the necessity to include these mycotoxins in analytical methods to perform more realistic risk assessments

Biomonitoring of enniatin B1 and its phase i metabolites in human urine: First large-scale study

Enniatins (Enns) are mycotoxins produced by Fusarium spp. which are a fungus widely spread throughout cereals and cereal-based products. Among all the identified enniatins, Enn B1 stands as one of the most prevalent analogues in cereals in Europe. Hence, the aim of this study was to evaluate for the first time the presence of Enn B1 and its phase I metabolites in 300 human urine samples using an ultrahigh-performance liquid chromatography high resolution mass spectrometry (UHPLC-Q-Orbitrap HRMS) methodology. Enn B1 was detected in 94.3% of samples ranging from 0.007 to 0.429 ng/mL (mean value: 0.065 ng/mL). In accordance with previous in vitro and in vivo analysis, hydroxylated metabolites (78.0% samples) and carbonylated metabolites (66.0% samples) were tentatively identified as the major products. Results from this biomonitoring study point to a frequent intake of Enn B1 in the studied population, suggesting that in-depth toxicological studies are needed in order to understand the potential effects in humans

Soluble RAGE as a severity marker in community acquired pneumonia associated sepsis

<p>Abstract</p> <p>Background</p> <p>Community-acquired pneumonia (CAP) is considered the most important cause of death from infectious disease in developed countries. Severity assessment scores partially address the difficulties in identifying high-risk patients. A lack of specific and valid pathophysiologic severity markers affect early and effective sepsis therapy. HMGB-1, sRAGE and RAGE have been involved in sepsis and their potential as severity markers has been proposed. The aim of this study was to evaluate HMGB-1, RAGE and sRAGE levels in patients with CAP-associated sepsis and determine their possible association with clinical outcome.</p> <p>Method</p> <p>We evaluated 33 patients with CAP-associated sepsis admitted to the emergency room and followed in the medical wards. Severity assessment scores (CURB-65, PSI, APACHE II, SOFA) and serologic markers (HMGB-1, RAGE, sRAGE) were evaluated on admission.</p> <p>Results</p> <p>Thirty patients with a diagnosis of CAP-associated sepsis were enrolled in the study within 24 hours after admission. Fourteen (46.6%) had pandemic (H1N1) influenza A virus, 2 (6.6%) had seasonal influenza A and 14 other diagnoses. Of the patients in the study group, 16 (53.3%) had a fatal outcome. ARDS was observed in 17 (56.6%) and a total of 22 patients had severe sepsis on admission (73%). The SOFA score showed the greatest difference between surviving and non-surviving groups (<it>P </it>= .003) with similar results in ARDS patients (<it>P </it>= .005). sRAGE levels tended to be higher in non-surviving (<it>P </it>= .058) and ARDS patients (<it>P </it>= .058). Logistic regression modeling demonstrated that SOFA (<it>P </it>= .013) and sRAGE (<it>P </it>= .05) were the only variables that modified the probability of a fatal outcome.</p> <p>Conclusion</p> <p>The association of elevated sRAGE with a fatal outcome suggests that it may have an independent causal effect in CAP. SOFA scores were the only clinical factor with the ability to identify surviving and ARDS patients.</p

Low temperature photoluminescence in ultra-thin germanium quantum wells

We measured the photoluminescence (PL) spectra of a series of Gen quantum wells as a function of temperature, from 2K to 50K. The PL spectra at 2.1K are dominated by broad emission lines, which can be interpreted as recombination across the indirect gap of the Si/Ge microstructure and are strongly inuenced by the interface morphology of each sample. Beyond T & 15K, all samples show identical spectra in which the broad structures are replaced by thin, strong lines. We interpret these changes as a quenching of the recpmbination across the gap PL of the microstructure and the appearance of defect-related peaks from the Si substrate