Fragmentation of Ammonium Nitrate Particles under Thermal Cycling

Ammonium nitrate finds application in explosives and chlorine-free slow-burning propellants. Different phases are known for this ammonium salt, each of them featured by peculiar bulk densities. As a consequence, the variation of storage temperature induces processes of expansion-contraction in the crystals, unless specific stabilization is performed. In this paper, a batch of raw ammonium nitrate particles has been thermally cycled between −30 °C to +60 °C and analyzed. Microscopic observations, particle size measurement, and X-ray microtomography showed that the particles undergo a progressive fragmentation process, with opening of internal cracks and voids. The tested material halved its mass-mean diameter after five thermal cycles. As a term of comparison, a phase-stabilized ammonium nitrate batch was tested under the same conditions, showing no effect

Establishing a diagnostic tool for assessing optimal treatment timing in Indian children with developing malocclusions

Objective: To interrelate chronological age, cervical vertebrae maturational stage and dental calcification stages and to establish latter as first level diagnostic tool to estimate timing of pubertal growth spurt. Materials and Methods: Sample derived from pretreatment panaromic and lateral cephalometric radiographs of patients 8-14 years old. Study sample divided into three groups depending upon Angle’s molar relation: Group I, Group II, Group III. According to chronological age, into: Group A: 8-11 years Group B:11-14 years, further separating males and female subjects in each group. Demirjian et al method was used to assess dental maturity and for skeletal maturity the New Improved Version of Cervical Vertebrae Maturation Method by Baccetti, Franchi and Mc Namara. Statistical analysis was performed using SPSS software package. Chi Square test and Spearman rank-order correlation coefficients measured the association between skeletal maturity indicators and dental calcification stages and statistical significance tested. Results&Conclusions: In females, permanent mandibular second molar Stage E signified circumpubertal phase corresponding with skeletal age CVMS II and for males, it was permanent mandibular first premolar stage E. Early orthodontic interventions for Angle’s Class I and Class II malocclusions should be performed at the circumpubertal period represented by CVMS II in Indian children and for Angle’s Class III malocclusion, facemask therapy beneficial in the prepubertal phase. Females showed higher significant correlation among skeletal and dental calcification stages compared to males

Virtual design bureau

В статье описывается краткая история Виртуального конструкторского бюро космического приборостроения за 5 лет его существования. В статье можно прочитать об основных, но при этом наиболее важных событиях в жизни ВКБ и кафедры точного приборостроения за этот период. ВКБ сыграло значительную роль в определении направления развитии кафедры. Самыми значимыми проектами являются создание студенческого Центра управления полетами космическими аппаратами и участие взапуске спутника "Томск-ТПУ-120".The article describes a brief 5-year history of the Virtual Design Bureau. In the article you can read about the most important events in the life of the VDB and the Department of Precision Instrument Making for this period. VDB played a significant role in determining the department development direction. The most significant projects are the creation of a student space flight control center and participation in the launch of the Tomsk-TPU-120 satellite

Integrating a nationally scaled workforce of community health workers in primary care: a modelling study.

Objective To model cost and benefit of a national community health worker workforce. Design Modelling exercise based on all general practices in England. Setting United Kingdom National Health Service Primary Care. Participants Not applicable. Data sources Publicly available data on general practice demographics, population density, household size, salary scales and screening and immunisation uptake. Main outcome measures We estimated numbers of community health workers needed, anticipated workload and likely benefits to patients. Results Conservative modelling suggests that 110,585 community health workers would be needed to cover the general practice registered population in England, costing £2.22bn annually. Assuming community health workerss could engage with and successfully refer 20% of eligible unscreened or unimmunised individuals, an additional 753,592 cervical cancer screenings, 365,166 breast cancer screenings and 482,924 bowel cancer screenings could be expected within respective review periods. A total of 16,398 additional children annually could receive their MMR1 at 12 months and 24,716 their MMR2 at five years of age. Community health workerss would also provide home-based health promotion and lifestyle support to patients with chronic disease. Conclusion A scaled community health worker workforce integrated into primary care may be a valuable policy alternative. Pilot studies are required to establish feasibility and impact in NHS primary care

Coarse race data conceals disparities in clinical risk score performance

Healthcare data in the United States often records only a patient's coarse race group: for example, both Indian and Chinese patients are typically coded as ``Asian.'' It is unknown, however, whether this coarse coding conceals meaningful disparities in the performance of clinical risk scores across granular race groups. Here we show that it does. Using data from 418K emergency department visits, we assess clinical risk score performance disparities across granular race groups for three outcomes, five risk scores, and four performance metrics. Across outcomes and metrics, we show that there are significant granular disparities in performance within coarse race categories. In fact, variation in performance metrics within coarse groups often exceeds the variation between coarse groups. We explore why these disparities arise, finding that outcome rates, feature distributions, and the relationships between features and outcomes all vary significantly across granular race categories. Our results suggest that healthcare providers, hospital systems, and machine learning researchers should strive to collect, release, and use granular race data in place of coarse race data, and that existing analyses may significantly underestimate racial disparities in performance.Comment: The first two authors contributed equally. Under revie

Big Mother or Small Baby: Which Predicts Hypertension?

According to the Barker hypothesis, intrauterine growth restriction and premature delivery adversely affect cardiovascular health in adult life. The association of childhood hypertension as a cardiovascular risk factor and birth weight has been understudied. In a prospective cohort study, the authors evaluated the effect of birth weight, gestational age, maternal prepregnancy body mass index (BMI), and child BMI z score at the time of enrollment on the systolic and diastolic blood pressure (BP) z score in 3024 (1373 women) consecutive outpatient clinic patients aged 2.05 to 18.58 years. The latest National Health and Nutrition Examination Survey (NHANES III) was used to calculate the age-dependent z scores. The median z scores of BMI (+0.48, range -6.96-6.64), systolic BP (+0.41, range -4.50-6.73), and diastolic BP (+0.34, range -3.15-+6.73) were all significantly greater than the NHANES III reference population. Systolic BP z score did not correlate with birth weight or gestational age, but did correlate with maternal prepregnancy BMI (r=090, P\u3c.0001) and BMI z score (r=209, P\u3c.0001). Diastolic BP z score positively correlated with birth weight (0.037, P=044), gestational age (r=052, P=005), BMI z score(r=106, P\u3c.0001), and maternal prepregnancy BMI (r=062, P=0007). In contrast to what would be expected from the Barker hypothesis, the authors found no negative correlation between BP z score and birth weight or gestational age. This study suggests that a high BMI, a big mom, and a high birth weight are more important risk factors for hypertension during childhood than low birth weight or gestational age. © 2010 Wiley Periodicals, Inc

Big Mother or Small Baby: Which Predicts Hypertension?

According to the Barker hypothesis, intrauterine growth restriction and premature delivery adversely affect cardiovascular health in adult life. The association of childhood hypertension as a cardiovascular risk factor and birth weight has been understudied. In a prospective cohort study, the authors evaluated the effect of birth weight, gestational age, maternal prepregnancy body mass index (BMI), and child BMI z score at the time of enrollment on the systolic and diastolic blood pressure (BP) z score in 3024 (1373 women) consecutive outpatient clinic patients aged 2.05 to 18.58 years. The latest National Health and Nutrition Examination Survey (NHANES III) was used to calculate the age-dependent z scores. The median z scores of BMI (+0.48, range -6.96-6.64), systolic BP (+0.41, range -4.50-6.73), and diastolic BP (+0.34, range -3.15-+6.73) were all significantly greater than the NHANES III reference population. Systolic BP z score did not correlate with birth weight or gestational age, but did correlate with maternal prepregnancy BMI (r=090, P\u3c.0001) and BMI z score (r=209, P\u3c.0001). Diastolic BP z score positively correlated with birth weight (0.037, P=044), gestational age (r=052, P=005), BMI z score(r=106, P\u3c.0001), and maternal prepregnancy BMI (r=062, P=0007). In contrast to what would be expected from the Barker hypothesis, the authors found no negative correlation between BP z score and birth weight or gestational age. This study suggests that a high BMI, a big mom, and a high birth weight are more important risk factors for hypertension during childhood than low birth weight or gestational age. © 2010 Wiley Periodicals, Inc

Lower Hemoglobin Correlates with Larger Stroke Volumes in Acute Ischemic Stroke

www.karger.com/cee This is an Open Access article licensed under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs 3.0 License (www.karger.com/OA-license), applicable to the online version of the article only. Distribution for non-commercial purposes only

Correction: Effect of Door-to-Door Screening and Awareness Generation Activities in the Catchment Areas of Vision Centers on Service Use: Protocol for a Randomized Experimental Study

[This corrects the article DOI: 10.2196/31951.]. The corrections will appear in the online version of the paper on the JMIR Publications website on January 18, 2022, with the publication of this correction notice. Because this was made after submission to PubMed, PubMed Central, and other full-text repositories, the corrected article has also been resubmitted to those repositories