Translating research into MCH service: comparison of a pilot project and a large-scale resource mothers program.

This study examines the process and effect of translating a pilot research project into a large-scale service program. In a pilot resource mothers program for pregnant teenagers, participants had fewer low birth weight infants than teenagers in the comparison group. In the corresponding large-scale service program, a similarly positive effect on low birth weight was not seen. In an effort to understand how these differences occurred, the evaluation methodologies and key characteristics that describe the background, infrastructure, components, and service providers of the two projects were compared. Important differences between the pilot project and the service program were seen in funding stability, diversity of staff, community versus health department ownership of the program, caseloads, and levels of training and supervision. It seems probable that these differences brought about changes in the intensity and character of the intervention from the pilot to the service program, leading to a reduction of the intervention's efficacy in reducing the number of low birth weight infants. The implications of these findings for researchers and program planners are discussed

The management and use of data on maternal and child health and crippled children: a survey.

With the advent of the Maternal and Child Health Services Block Grant, both maternal and child health programs and crippled children's (CC) programs at the State level have assumed greater responsibility for identifying populations in need, planning appropriate services for them, and monitoring progress toward program objectives. To determine the capabilities of eight Southeastern States to produce and apply the data necessary to accomplish those tasks, a survey of data systems available to, and used by, perinatal and CC programs in the Southeast was undertaken. Findings of the survey suggested that the data available to perinatal programs were more useful for planning and evaluation than those available to CC programs, primarily due to the vital statistics data systems in each State. The major data management needs of the region include (a) measuring the health status of populations served by public perinatal programs, (b) measuring services received by population groups considered in need of public perinatal care, (c) estimating the incidence and prevalence of handicapping conditions among children, and (d) measuring the outcomes of CC programs. If these shortcomings are addressed, the programs will be in better positions for effective planning and evaluation. To improve data management and utilization capabilities, the programs may need to engage technical assistance and consultation from sources outside their service-oriented agencies

Unimolecular decomposition kinetics of the stabilised Criegee intermediates CH₂OO and CD₂OO

Decomposition kinetics of stabilised CH2OO and CD2OO Criegee intermediates have been investigated as a function of temperature (450–650 K) and pressure (2–350 Torr) using flash photolysis coupled with time-resolved cavity-enhanced broadband UV absorption spectroscopy. Decomposition of CD2OO was observed to be faster than CH2OO under equivalent conditions. Production of OH radicals following CH2OO decomposition was also monitored using flash photolysis with laser-induced fluorescence (LIF), with results indicating direct production of OH in the v = 0 and v = 1 states in low yields. Master equation calculations performed using the Master Equation Solver for Multi-Energy well Reactions (MESMER) enabled fitting of the barriers for the decomposition of CH2OO and CD2OO to the experimental data. Parameterisations of the decomposition rate coefficients, calculated by MESMER, are provided for use in atmospheric models and implications of the results are discussed. For CH2OO, the MESMER fits require an increase in the calculated barrier height from 78.2 kJ mol−1 to 81.8 kJ mol−1 using a temperature-dependent exponential down model for collisional energy transfer with 〈ΔE〉down = 32.6(T/298 K)1.7 cm−1 in He. The low- and high-pressure limit rate coefficients are k1,0 = 3.2 × 10−4(T/298)−5.81exp(−12 770/T) cm3 s−1 and k1,∞ = 1.4 × 1013(T/298)0.06exp(−10 010/T) s−1, with median uncertainty of ∼12% over the range of experimental conditions used here. Extrapolation to atmospheric conditions yields k1(298 K, 760 Torr) = 1.1+1.5−1.1 × 10−3 s−1. For CD2OO, MESMER calculations result in 〈ΔE〉down = 39.6(T/298 K)1.3 cm−1 in He and a small decrease in the calculated barrier to decomposition from 81.0 kJ mol−1 to 80.1 kJ mol−1. The fitted rate coefficients for CD2OO are k2,0 = 5.2 × 10−5(T/298)−5.28exp(−11 610/T) cm3 s−1 and k2,∞ = 1.2 × 1013(T/298)0.06exp(−9800/T) s−1, with overall error of ∼6% over the present range of temperature and pressure. The extrapolated k2(298 K, 760 Torr) = 5.5+9.2−5.5 × 10−3 s−1. The master equation calculations for CH2OO indicate decomposition yields of 63.7% for H2 + CO2, 36.0% for H2O + CO and 0.3% for OH + HCO with no significant dependence on temperature between 400 and 1200 K or pressure between 1 and 3000 Torr

Time-resolved measurements of product formation in the low-temperature (550-675 K) oxidation of neopentane : a probe to investigate chain-branching mechanism

Product formation, in particular ketohydroperoxide formation and decomposition, were investigated in time-resolved, Cl-atom initiated neopentane oxidation experiments in the temperature range 550-675 K using a photoionization time-of-flight mass spectrometer. Ionization light was provided either by Advanced Light Source tunable synchrotron radiation or similar to 10.2 eV fixed energy radiation from a H-2-discharge lamp. Experiments were performed both at 1-2 atm pressure using a high-pressure reactor and also at similar to 9 Torr pressure employing a low-pressure reactor for comparison. Because of the highly symmetric structure of neopentane, ketohydroperoxide signal can be attributed to a 3-hydroperoxy-2,2-dimethylpropanal isomer, i.e. from a gamma-ketohydroperoxide (gamma-KHP). The photoionization spectra of the gamma-KHP measured at low-and high pressures and varying oxygen concentrations agree well with each other, further supporting they originate from the single isomer. Measurements performed in this work also suggest that the "Korcek" mechanism may play an important role in the decomposition of 3-hydroperoxy-2,2-dimethylpropanal, especially at lower temperatures. However, at higher temperatures where gamma-KHP decomposition to hydroxyl radical and oxy-radical dominates, oxidation of the oxy-radical yields a new important channel leading to acetone, carbon monoxide, and OH radical. Starting from the initial neopentyl + O-2 reaction, this channel releases altogether three OH radicals. A strongly temperature-dependent reaction product is observed at m/z = 100, likely attributable to 2,2-dimethylpropanedial.Peer reviewe

The impact of the third O-2 addition reaction network on ignition delay times of neo-pentane

We studied the oxidation of neo-pentane by combining experiments, theoretical calculations, and mechanistic developments to elucidate the impact of the 3rd O 2 addition reaction network on ignition delay time predictions. The experiments are based on photoionization mass spectrometry in jet-stirred and time-resolved flow reactors allowing for sensitive detection of the keto-hydroperoxide (KHP) and keto-dihydroperoxide (KDHP) intermediates. With neo-pentane exhibiting a unique symmetric molecular structure, which consequently results only in single KHP and KDHP isomers, theoretical calculations of ionization and fragment appearance energies and of absolute photoionization cross sections enabled the unambiguous identification and quantification of the KHP intermediate. Its temperature and time-resolved profiles together with calculated and experimentally observed KHP-to-KDHP signal ratios were compared to simulation results based on a newly developed mechanism that describes the 3rd O-2 addition reaction network. A satisfactory agreement has been observed between the experimental data points and the simulation results, thus adding confidence to the model's overall performance. Finally, this mechanism was used to predict ignition delay times reported previously in shock tube and rapid compression machine experiments (J. Bugler et al., Combust. Flame 163 (2016) 138-156). While the model accurately reproduces the experimental data, simulations with and without the 3rd O-2 addition reaction network included reveal only a negligible effect on the predicted ignition delay times at 10 and 20 atm. According to model calculations, low temperatures and high pressures promote the importance of the 3rd O-2 addition reactions. (c) 2020 The Combustion Institute. Published by Elsevier Inc. All rights reserved.Peer reviewe

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Abstract Background: Many patients with congestive heart failure (CHF) have chronic kidney insufficiency (CKI) and anemia. Aims: The purpose of this review is to clarify the relationship between these three factors and to study the effect of correction of anemia in CHF and CKI. Findings: Anemia, CHF and CKI are each capable of causing or worsening each other. Thus they form a vicious circle which can result in progressive CHF, CKI and anemia. Aggressive therapy of CHF, CKI and control of the associated anemia with erythropoietin and i.v. iron can prevent the progression of CHF and CKI, reduce hospitalization, and improve quality of life. Conclusion: CHF patients are a major source of end-stage renal failure patients and deserve special attention. If treated well and early, progressive heart failure and renal failure can be prevented. Cooperation between nephrologists, cardiologists, and other internists will improve the care of all three conditions and prevent their progression

Seasonality of Formic Acid (HCOOH) in London during the ClearfLo Campaign

Following measurements in the winter of 2012, formic acid (HCOOH) and nitric acid (HNO3) were measured using a chemical ionization mass spectrometer (CIMS) during the Summer Clean Air for London (ClearfLo) campaign in London, 2012. Consequently, the seasonal dependence of formic acid sources could be better understood. A mean formic acid concentration of 1.3 ppb and a maximum of 12.7 ppb was measured which is significantly greater than that measured during the winter campaign (0.63 ppb and 6.7 ppb, respectively). Daily calibrations of formic acid during the summer campaign gave sensitivities of 1.2 ion counts s-1 parts per trillion (ppt) by volume-1 and a limit of detection of 34 ppt. During the summer campaign, there was no correlation between formic acid and anthropogenic emissions such as NOx and CO or peaks associated with the rush hour as was identified in the winter. Rather, peaks in formic acid were observed that correlated with solar irradiance. Analysis using a photochemical trajectory model has been conducted to determine the source of this formic acid. The contribution of formic acid formation through ozonolysis of alkenes is important but the secondary production from biogenic VOCs could be the most dominant source of formic acid at this measurement site during the summer

How does study quality affect the results of a diagnostic meta-analysis?

Background: The use of systematic literature review to inform evidence based practice in diagnostics is rapidly expanding. Although the primary diagnostic literature is extensive, studies are often of low methodological quality or poorly reported. There has been no rigorously evaluated, evidence based tool to assess the methodological quality of diagnostic studies. The primary objective of this study was to determine the extent to which variations in the quality of primary studies impact the results of a diagnostic meta-analysis and whether this differs with diagnostic test type. A secondary objective was to contribute to the evaluation of QUADAS, an evidence-based tool for the assessment of quality in diagnostic accuracy studies. Methods: This study was conducted as part of large systematic review of tests used in the diagnosis and further investigation of urinary tract infection (UTI) in children. All studies included in this review were assessed using QUADAS, an evidence-based tool for the assessment of quality in systematic reviews of diagnostic accuracy studies. The impact of individual components of QUADAS on a summary measure of diagnostic accuracy was investigated using regression analysis. The review divided the diagnosis and further investigation of UTI into the following three clinical stages: diagnosis of UTI, localisation of infection, and further investigation of the UTI. Each stage used different types of diagnostic test, which were considered to involve different quality concerns. Results: Many of the studies included in our review were poorly reported. The proportion of QUADAS items fulfilled was similar for studies in different sections of the review. However, as might be expected, the individual items fulfilled differed between the three clinical stages. Regression analysis found that different items showed a strong association with test performance for the different tests evaluated. These differences were observed both within and between the three clinical stages assessed by the review. The results of regression analyses were also affected by whether or not a weighting (by sample size) was applied. Our analysis was severely limited by the completeness of reporting and the differences between the index tests evaluated and the reference standards used to confirm diagnoses in the primary studies. Few tests were evaluated by sufficient studies to allow meaningful use of meta-analytic pooling and investigation of heterogeneity. This meant that further analysis to investigate heterogeneity could only be undertaken using a subset of studies, and that the findings are open to various interpretations. Conclusion: Further work is needed to investigate the influence of methodological quality on the results of diagnostic meta-analyses. Large data sets of well-reported primary studies are needed to address this question. Without significant improvements in the completeness of reporting of primary studies, progress in this area will be limited