Gold-black manufacture, microstructure, and optical characterization.

A previous contribution formulates a first-principle dipole antenna theory for predicting the polarization-sensitive directional spectral absorptance of gold-black in the near infrared. The current contribution chronicles a successful effort to validate that theory. After a brief review of gold-black history, we describe in some detail the design and construction of a vapor-deposition cell for laying down gold-black coatings on a mirrorlike gold substrate. The microstructure of 4- and 8-µm-thick coatings is revealed using scanning electron microscopy. An automated bench-level reflectometer has been used to measure the in-plane bidirectional reflectivity of the gold-black coatings in the visible (532 nm) and near-infrared (800 nm) for p and s polarization. Measurements are reported over incident zenith angles ranging between 10 and 50 deg. Results obtained using the apparatus are consistent with the dipole antenna theory in this range of incident zenith angles.

Knowledge, Attitude, Practice and Stigma Related to COVID-19: A Nigerian Perspective.

Pandemics have claimed an estimated 414 million lives from 165 AD to present, with COVID-19 pandemic killing close to 2 million people. The best counter for pandemics has been the use of vaccines, but before it is widely available, the best strategy is to avoid being infected. COVID-19 pandemic was met by behaviours and attitudes ranging from unbelief to fear of dying and stigmatisation of those who have contracted the virus or recovered from the disease. This study aimed to investigate the knowledge, attitudes, practices (KAP), fear and stigma of the populace towards COVID-19 from state to state. This research was a cross-sectional study carried out from April to October 2020. Data was obtained through a structured questionnaire distributed to 650 individuals. Respondents who participated were 591 (males n= 335 and females n= 256) and aged 18-60 years (mean age 30.25 ± 10.45 years, range 18-60) drawn from five states in the north-central region of Nigeria. The results show that 98.3% of participants believe that COVID-19 disease exists. Still, not everyone wears face masks, avoid crowded places, practice social distancing or follow the WHO-hand-washing technique as measures to curb the spread of the disease. Only 60.5% of the participants believe that lockdown is an effective measure to reduce transmission risk. 55.6% will stigmatise those who just recovered from the disease, 75.3% are afraid to visit high-risk areas as part of the protective measures, but only about 12% believe that every infected person will die. More males (28.3%) than females (17.6%) believe that taking herbs can cure the disease (P<0.01). All government and nongovernmental organizations must develop more awareness programs to win the battle against COVID-19 disease as the second wave is emerging.

Improving Resident Self-Efficacy in Tracheostomy Management Using a Novel Curriculum.

Introduction: Patients receiving pediatric tracheostomy have significant risk for mortality due to compromised airway. Timely management of airway emergencies in children with tracheostomies is an important clinical skill for pediatricians. We developed this curriculum to improve residents' self-efficacy with tracheostomy management. Methods: We collected baseline data on 67 residents from two hospitals while creating a blended curriculum with video-based instruction on routine tracheostomy change and team management of tracheostomy emergency. Forty residents enrolled in the curriculum. During an ICU rotation, they received face-to-face instruction on routine tracheostomy change in small groups, followed by assessment of managing a tracheostomy emergency during a simulation. A video completed prior to the simulation took 9 minutes, the routine tracheostomy change didactic session took 15 minutes, and the simulation instruction was completed in 10-15 minutes. We collected feedback on the effectiveness of the curriculum from the participants. Results: All 107 residents from the baseline and intervention groups completed the self-efficacy survey. The intervention group had significantly higher changes in scores across all self-efficacy domains than the baseline group. On the curriculum feedback survey, residents rated the curriculum very highly, between 4.4 and 4.8 on a 5-point Likert scale. Discussion: Our blended curriculum increased learners' self-efficacy and promoted learner competence in tracheostomy management. Residents scored more than 80% across all aspects of simulation assessment and reported higher self-efficacy scores following our curricular intervention.

First-principle model for the directional spectral absorptivity of gold-black in the near infrared.

Gold-black coatings formed by evaporation and subsequent sublimation of pure gold in an inert low-pressure atmosphere are used to enhance absorption of thermal radiation. Previous attempts to predict the spectral absorptivity of gold-black coatings have typically assumed a granular continuum with effective bulk optical properties. In the current effort the principles of diffusion-limited aggregation (DLA) are applied to mimic the observed microstructure of actual gold-black layers consisting of a random fractal distribution of dendritic gold filaments that are postulated to behave as dipole antennas. Absorption of incident electromagnetic radiation by individual filaments is predicted using a unique time-dependent lossy antenna model drawing on the Drude-Sommerfeld free-electron theory. Single-filament spectral absorptivities are combined based on the DLA microstructure model to predict the spectral and, for the first time, the directional absorptivity of the gold-black layer. Results for normal spectral absorptivity are shown to be in good agreement with measurements reported in the literature.

Monte Carlo ray-trace diffraction based on the Huygens-Fresnel principle.

The goal of this effort is to establish the conditions and limits under which the Huygens-Fresnel principle accurately describes diffraction in the Monte Carlo ray-trace (MCRT) environment. This goal is achieved by systematic intercomparison of dedicated experimental, theoretical, and numerical results. We evaluate the success of the Huygens-Fresnel principle by predicting and carefully measuring the diffraction fringes produced by both single slit and circular apertures. We then compare the results from the analytical and numerical approaches with each other and with dedicated experimental results. We conclude that use of the MCRT method to accurately describe diffraction requires that careful attention be paid to the interplay among the number of aperture points, the number of rays traced per aperture point, and the number of bins on the screen. This conclusion is supported by standard statistical analysis, including the adjusted coefficient of determination, Radj2, the rms deviation, and the reduced chi-square statistic, χv2.

Diffraction and polarization effects in Earth radiation budget measurements.

Thermal radiation emitted and reflected from the Earth and viewed from near-Earth orbit may be characterized by its spectral distribution, its degree of coherence, and its state of polarization. The current generation of broadband Earth radiation budget instruments has been designed to minimize the effect of diffraction and polarization on science products. We used Monte Carlo ray-trace (MCRT) models that treat individual rays as quasi-monochromatic, polarized entities to explore the possibility of improving the performance of such instruments by including measures of diffraction and polarization during calibration and operation. We have demonstrated that diffraction and polarization sensitivity associated with typical Earth radiation budget instrument design features has a negligible effect on measurements.

Preparedness of pediatric residents for fellowship: a survey of US neonatal-perinatal fellowship program directors.

OBJECTIVE: To evaluate the preparedness of pediatric residents entering accredited neonatal-perinatal medicine (NPM) fellowships in the United States. STUDY DESIGN: A multi-domain, validated survey was distributed to Program Directors (PDs) of US NPM fellowship programs. The 47-item survey explored 5 domains: professionalism, independent practice, psychomotor ability, clinical evaluation, and academia. A systematic, qualitative analysis on free-text comments was also performed. RESULTS: Sixty-one PDs completed the survey, for a response rate of 62% (61/98). For entering fellows, PDs assessed performance in professionalism positively, including 76% as communicating effectively with parents and 90% treating residents/house-staff with respect. In contrast, most PDs rated performance in psychomotor abilities negatively, including 59% and 79% as deficient in bag-and-mask ventilation and neonatal endotracheal intubation, respectively. Although 62% of PDs assessed entering fellows positively for genuine interest in academic projects, fewer than 10% responded positively that entering fellows understood research protocol design, basic statistics, or were capable of writing a cohesive manuscript well. Thematic clustering of qualitative data revealed deficits in psychomotor ability and academia/scholarship. CONCLUSIONS: On the basis of the perspective of front line educators, graduating pediatric residents are underprepared for subspecialty fellowship training in NPM. To provide the best preparation for pediatric graduates who pursue advanced training, changes to residency education to address deficiencies in these important competencies are warranted.

Bidirectional reflection effects in practical integrating spheres.

Integrating spheres play a central role in radiometric instrument calibration, surface optical property measurement, and radiant source characterization. Our work involves a simulation, based on the Monte Carlo ray-trace (MCRT) of bidirectional reflections within a practical integrating sphere pierced with two viewing ports. We used data from the literature to create an empirical model for the bidirectional reflection distribution function (BRF) of Spectralon suitable for use in the MCRT environment. The ratio of power escaping through the two openings is shown to vary linearly with wall absorptivity for both diffuse and bidirectional reflections. The sensitivity of this ratio to absorptivity is shown to be less when reflections are weakly bidirectional.

Self-Management and Transition Readiness Assessment: Development, Reliability, and Factor Structure of the STARx Questionnaire.

INTRODUCTION: The Self-Management and Transition to Adulthood with Rx=Treatment (STARx) Questionnaire was developed to collect information on self-management and health care transition (HCT) skills, via self-report, in a broad population of adolescents and young adults (AYAs) with chronic conditions. METHODS: Over several iterations, the STARx questionnaire was created with AYA, family, and health provider input. The development and pilot testing of the STARx Questionnaire took place with the assistance of 1219 AYAs with different chronic health conditions, in multiple institutions and settings over three phases: item development, pilot testing, reliability and factor structuring. RESULTS: The three development phases resulted in a final version of the STARx Questionnaire. The exploratory factor analysis of the third version of the 18-item STARx identified six factors that accounted for about 65% of the variance: Medication management, Provider communication, Engagement during appointments, Disease knowledge, Adult health responsibilities, and Resource utilization. Reliability estimates revealed good internal consistency and temporal stability, with the alpha coefficient for the overall scale being .80. The STARx was developmentally sensitive, with older patients scoring significantly higher on nearly every factor than younger patients. CONCLUSION: The STARx Questionnaire is a reliable, self-report tool with adequate internal consistency, temporal stability, and a strong, multidimensional factor structure. It provides another assessment strategy to measure self-management and transition skills in AYAs with chronic conditions.

Return to contingency: developing a coherent strategy for future R2E/R3 land medical capabilities.

Key to deploying forces in the future will be the provision of a rapidly deployable Deployed Hospital Capability. Developing this capability has been the focus of 34 Field Hospital and 2nd Medical Brigade over the last 18 months and this paper describes a personal account of this development work to date. Future contingent Deployed Hospital Capability must meet the requirements of Defence; that is to be rapidly deployable delivering a hospital standard of care. The excellence seen in clinical delivery on recent operations is intensive; in personnel, equipment, infrastructure and sustainment. The challenge in developing a coherent capability has been in balancing the clinical capability and capacity against strategic load in light of recent advances in battlefield medicine. This paper explores the issues encountered and solutions found to date in reconstituting a Very High Readiness Deployed Hospital Capability.

Dietary modifications alone do not improve bone mineral density in children with idiopathic hypercalciuria.

Prior cross-sectional studies have demonstrated an association between hypercalciuria and low bone mineral density (BMD) in children and adults. However, the natural history of BMD in children with hypercalciuria and its response to therapy has not been evaluated. The objective of this retrospective study was to determine the change over time in lumbar (L1 - L4) BMD Z-score measured on sequential DXA scans in 19 children with hypercalciuria treated with dietary recommendations without (n = 12, Group A) and with citrate (n = 7, Group B). The mean lumbar bone density Z-score/year decreased in Group A (-0.11 ±/0.41) indicating that children with hypercalciuria lose L1 - L4 BMD over time. In contrast, the L1 - L4 BMD Zscore/ year increased in Group B (0.19 ± 0.38) suggesting that pharmacologic therapy may reverse this trend. Similarly 75% of patients in Group A, but only 29% patients in Group B had a decrease in L1 - L4 BMD. There was a definite, although not significant, trend towards improved mean bone mineral density Z-score per year and a lower percentage of patients with a decreased Z-score in hypercalciuric children treated with potassium citrate. Our findings suggest the possibility that dietary recommendations alone is not adequate as the bone mineral density of children with hypercalciuria will decrease over time, potentially increasing the risk for osteoporosis as an adult.

The effect of vascular access location and size on circuit survival in pediatric continuous renal replacement therapy: a report from the PPCRRT registry.

PURPOSE: Well-functioning vascular access is essential for the provision of adequate CRRT. However, few data exist to describe the effect of catheter size or location on CRRT performance in the pediatric population. METHODS: Data for vascular access site, size, and location, as well as type of anticoagulant used and patient demographic data were gathered from the ppCRRT registry. Kaplan-Meier curves were generated and then analyzed by log-rank test or Cox Proportional Hazards model. RESULTS: Access diameter was found to significantly affect circuit survival. None of the 5 French catheters lasted longer than 20 hours. Seven and 9 French, but not 8 French, catheters fared worse than larger diameter catheters (p=0.002). Circuits associated with internal jugular access survived longer than subclavian or femoral access associated circuits (p<0.05). Circuit survival was also found to be favorably associated with the CVVHD modality (p<0.001). CONCLUSIONS: Functional CRRT circuit survival in children is favored by larger catheter diameter, internal jugular vein insertion site and CVVHD. For patients requiring catheter diameters less than 10 French, CRRT circuit survival might be optimized if internal jugular vein insertion is feasible. Conversely, when a vascular access site other than the internal jugular vein is most prudent, consideration should be given to using the largest diameter catheter appropriate for the size of the child. The CVVHD modality was associated with longer circuit survival, but the mechanism by which this occurs is unclear.

The Prospective Pediatric Continuous Renal Replacement Therapy (ppCRRT) Registry: design, development and data assessed.

Many issues plague the pediatric ARF outcome literature, which include data only from single center sources, a relative lack of prospective study, mixture within studies of renal replacement therapy modality without stratification and inconsistent use of methods to control for patient illness severity in outcome analysis. Since January 2001, the Prospective Pediatric CRRT (ppCRRT) Registry Group has been collecting data from multiple United States pediatric centers to obtain demographic data regarding pediatric patients who receive CRRT, assess the effect of different CRRT prescriptions on circuit function and evaluate the impact of clinical variables on patient outcome. The aim of the current paper is to describe the ppCRRT Registry design, review the decision process and rationale for the options chosen for the ppCRRT format and discuss the analysis plan and future projects envisioned for the ppCRRT Registry.

Single-dose pharmacokinetics and tolerability of everolimus in stable pediatric renal transplant patients.

Everolimus (Certican; RAD), a novel macrolide with potent immunosuppressive and anti-proliferative activities, prevents acute rejection in adult recipients of renal transplantation. This phase I trial conducted in stable pediatric renal transplant patients examined the single-dose pharmacokinetics, safety, and tolerability of everolimus in combination with cyclosporin A (CsA; Neoral) and corticosteroids, with or without azathioprine. Nineteen pediatric patients were enrolled and received a single 1.2 mg/m2 dose of everolimus. Everolimus was safe and well tolerated, with a low incidence of adverse events reported and none judged to be related to the study medication. Everolimus administration did not increase infection rates or produce clinically significant changes in vital signs or changes in electrocardiograms. Apparent clearance and volume of distribution of everolimus increased with age, weight, and body surface area in a generally linear manner across the pediatric demographic ranges. Compared with adults from a previous study, apparent clearance (L/h) and distribution volume (L) were lower in pediatric patients, whereas the elimination half-life was similar. Single-dose everolimus co-administration did not affect the steady-state pharmacokinetics of CsA. Based on this information, pediatric patients will need a dose scaled down for body size, but can probably maintain the same twice-daily dosing schedule used in adults.

The intestine expresses pancreatic triacylglycerol lipase: regulation by dietary lipid.

We identified the enzyme responsible for alkaline lipolysis in mucosa of rat small intestine. RT-PCR was used to amplify a transcript that, by cloning and sequencing, is identical to pancreatic triacylglycerol lipase. In rats fed normal laboratory chow, pancreatic triacylglycerol lipase mRNA was detected in all four quarters of the small intestine, with the first quarter expressing about three times as much of this transcript as was found in the more distal three-quarters combined. Both acutely and chronically administered dietary fat were shown to regulate pancreatic triacylglycerol lipase mRNA expression and lipase activity. The synthesis of pancreatic triacylglycerol lipase protein by the small intestine was demonstrated by in vivo radiolabeling experiments using [(35)S]methionine/cysteine followed by immunoprecipitation with an anti-pancreatic triacylglycerol lipase antibody. Immunohistochemical studies suggest that pancreatic triacylglycerol lipase protein expression is restricted to enterocytes throughout the small intestine. To our knowledge, this is the first report identifying rat small intestinal mucosa as a site of pancreatic triacylglycerol lipase synthesis and the first demonstration of its modulation in the mucosa by dietary fat. We propose that pancreatic triacylglycerol lipase is used by the intestine to hydrolyze the mucosal triacylglycerol that is not transported in chylomicrons.

Determination of the thermal offset of the Eppley precision spectral pyranometer.

Eppley's precision spectral pyranometer (PSP) is used in networks around the world to measure downwelling diffuse and global solar irradiance at the surface of the Earth. In recent years several studies have shown significant discrepancy between irradiances measured by pyranometers and those computed by atmospheric radiative transfer models. Pyranometer measurements have been questioned because observed diffuse irradiances sometimes are below theoretical minimum values for a pure molecular atmosphere, and at night the instruments often produce nonzero signals ranging between +5 and -10 W m(-2). We install thermistor sondes in the body of a PSP as well as on its inner dome to monitor the temperature gradients within the instrument, and we operate a pyrgeometer (PIR) instrument side by side with the PSP. We derive a relationship between the PSP output and thermal radiative exchange by the dome and the detector and a relationship between the PSP output and the PIR thermopile output (net-IR). We determine the true PSP offset by quickly capping the instrument at set time intervals. For a ventilated and shaded PSP, the thermal offset can reach -15 W m(-2) under clear skies, whereas it remains close to zero for low overcast clouds. We estimate the PSP thermal offset by two methods: (1) using the PSP temperatures and (2) using the PIR net-IR signal. The offset computed from the PSP temperatures yields a reliable estimate of the true offset (+/-1 W m(-2)). The offset computed from net-IR is consistent with the true offset at night and under overcast skies but predicts only part of the true range under clear skies.

Stress tolerance in transgenic tobacco seedlings that overexpress glutathione S-transferase/glutathione peroxidase.

Overexpression of a tobacco glutathione S-transferase with glutathione peroxidase activity (GST/GPX) in transgenic tobacco (Nicotiana tabacum L.) enhanced seedling growth under a variety of stressful conditions. In addition to increased GST and GPX activity, transgenic GST/GPX-expressing (GST+) seedlings had elevated levels of monodehydroascorbate reductase activity. GST+ seedlings also contained higher levels of glutathione and ascorbate than wild-type seedlings and the glutathione pools were more oxidized. Thermal or salt-stress treatments that inhibited the growth of wild-type seedlings also caused increased levels of lipid peroxidation. These treatments had less effect on the growth of GST+ seedling growth and did not lead to increased lipid peroxidation. Stress-induced damage resulted in reduced metabolic activity in wild-type seedlings while GST+ seedlings maintained metabolic activity levels comparable to seedlings grown under control conditions. These results indicate that overexpression of GST/GPX in transgenic tobacco seedlings provides increased glutathione-dependent peroxide scavenging and alterations in glutathione and ascorbate metabolism that lead to reduced oxidative damage. We conclude that this protective effect is primarily responsible for the ability of GST+ seedlings to maintain growth under stressful conditions.

Thermal dependence of malate synthase activity and its relationship to the thermal dependence of seedling emergence.

Cotton yields are often reduced by low temperatures at early planting dates. Improved seedling metabolism at low temperatures may enhance seedling performance. The glyoxylate cycle plays a role in the metabolism of stored lipids, and thus thermal limitations on the function of malate synthase (EC 4.1.3.2) may be involved in low-temperature limitations on seedlings. The thermal dependencies of the apparent K(M) and maximal velocity for the malate synthases from cotton (Gossypium hirsutum L.) and sunflower (Helianthus annuus L.) were determined across a 15-45 degrees C thermal range and used to estimate the thermal dependence of reaction velocity. The thermal dependence of seedling emergence was monitored for both species. The thermal dependencies of predicted reaction velocity and the measured rates of seedling emergence are correlated (cotton r(2) = 0.9, sunflower r(2) = 0.76) and suggest that the thermal dependencies of enzymes predicted from basic kinetic parameters may be useful indicators of the thermal dependence of more complex whole-plant processes.