Evolution and Control of 2219 Aluminum Microstructural Features Through Electron Beam Freeform Fabrication

NASA Technical Reports Server (NTRS)

Taminger, Karen M.; Hafley, Robert A.; Domack, Marcia S.

2006-01-01

The layer-additive nature of the electron beam freeform fabrication (EBF3) process results in a tortuous thermal path producing complex microstructures including: small homogeneous equiaxed grains; dendritic growth contained within larger grains; and/or pervasive dendritic formation in the interpass regions of the deposits. Several process control variables contribute to the formation of these different microstructures, including translation speed, wire feed rate, beam current and accelerating voltage. In electron beam processing, higher accelerating voltages embed the energy deeper below the surface of the substrate. Two EBF3 systems have been established at NASA Langley, one with a low-voltage (10-30kV) and the other a high-voltage (30-60 kV) electron beam gun. Aluminum alloy 2219 was processed over a range of different variables to explore the design space and correlate the resultant microstructures with the processing parameters. This report is specifically exploring the impact of accelerating voltage. Of particular interest is correlating energy to the resultant material characteristics to determine the potential of achieving microstructural control through precise management of the heat flux and cooling rates during deposition.

78 FR 29387 - Government-Owned Inventions, Available for Licensing

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-20

... System for Physiologically Modulating Action Role-playing Open World Video Games and Simulations Which... Deposition Measurement for the Electron Beam Free Form Fabrication (EBF3) Process; NASA Case No.: LAR-17887-1... Modulating Videogames and Simulations Which Use Gesture and Body Image Sensing Control Input Devices; NASA...

Electron Beam Freeform Fabrication: A Rapid Metal Deposition Process

NASA Technical Reports Server (NTRS)

Taminger, Karen M. B.; Hafley, Robert A.

2003-01-01

Manufacturing of structural metal parts directly from computer aided design (CAD) data has been investigated by numerous researchers over the past decade. Researchers at NASA Langley REsearch Center are developing a new solid freeform fabrication process, electron beam freeform fabrication (EBF), as a rapid metal deposition process that works efficiently with a variety of weldable alloys. The EBF process introduces metal wire feedstock into a molten pool that is created and sustained using a focused electron beam in a vacuum environment. Thus far, this technique has been demonstrated on aluminum and titanium alloys of interest for aerospace structural applications nickel and ferrous based alloys are also planned. Deposits resulting from 2219 aluminum demonstrations have exhibited a range of grain morphologies depending upon the deposition parameters. These materials ave exhibited excellent tensile properties comparable to typical handbook data for wrought plate product after post-processing heat treatments. The EBF process is capable of bulk metal deposition at deposition rated in excess of 2500 cubic centimeters per hour (150 cubic inches per our) or finer detail at lower deposition rates, depending upon the desired application. This process offers the potential for rapidly adding structural details to simpler cast or forged structures rather than the conventional approach of machining large volumes of chips to produce a monolithic metallic structure. Selective addition of metal onto simpler blanks of material can have a significant effect on lead time reduction and lower material and machining costs.

Additively Manufactured Low Cost Upper Stage Combustion Chamber

NASA Technical Reports Server (NTRS)

Protz, Christopher; Cooper, Ken; Ellis, David; Fikes, John; Jones, Zachary; Kim, Tony; Medina, Cory; Taminger, Karen; Willingham, Derek

2016-01-01

Over the past two years NASA's Low Cost Upper Stage Propulsion (LCUSP) project has developed Additive Manufacturing (AM) technologies and design tools aimed at reducing the costs and manufacturing time of regeneratively cooled rocket engine components. High pressure/high temperature combustion chambers and nozzles must be regeneratively cooled to survive their operating environment, causing their design fabrication to be costly and time consuming due to the number of individual steps and different processes required. Under LCUSP, AM technologies in Sintered Laser Melting (SLM) GRCop-84 and Electron Beam Freeform Fabrication (EBF3) Inconel 625 have been significantly advanced, allowing the team to successfully fabricate a 25k-class regenerative chamber. Estimates of the costs and schedule of future builds indicate cost reductions and significant schedule reductions will be enabled by this technology. Characterization of the microstructural and mechanical properties of the SLM-produced GRCop-84, EBF3 Inconel 625 and the interface layer between the two has been performed and indicates the properties will meet the design requirements. The LCUSP chamber is to be tested with a previously demonstrated SLM injector in order to advance the Technology Readiness Level (TRL) and demonstrate the capability of the application of these processes. NASA is advancing these technologies to reduce cost and schedule for future engine applications and commercial needs.

Height Control and Deposition Measurement for the Electron Beam Free Form Fabrication (EBF3) Process

NASA Technical Reports Server (NTRS)

Hafley, Robert A. (Inventor); Seufzer, William J. (Inventor)

2017-01-01

A method of controlling a height of an electron beam gun and wire feeder during an electron freeform fabrication process includes utilizing a camera to generate an image of the molten pool of material. The image generated by the camera is utilized to determine a measured height of the electron beam gun relative to the surface of the molten pool. The method further includes ensuring that the measured height is within the range of acceptable heights of the electron beam gun relative to the surface of the molten pool. The present invention also provides for measuring a height of a solid metal deposit formed upon cooling of a molten pool. The height of a single point can be measured, or a plurality of points can be measured to provide 2D or 3D surface height measurements.

Maternal prenatal attitudes and postnatal breast-feeding behaviours in rural Bangladesh.

PubMed

Yu, Elaine A; Thomas, Joan S; Owais, Aatekah; Tirmizi, Noor; Faruque, Asg; Das, Sumon K; Rahman, Shahed; Schwartz, Benjamin; Stein, Aryeh D

2015-03-01

To assess the relationships between maternal breast-feeding intention, attitudes, self-efficacy and knowledge at 7 months' gestation with exclusive or full breast-feeding at 3 months postpartum. Prospective cohort study with structured home interviews during pregnancy and 3 months after delivery. Two rural sub-districts of Kishoreganj district, Bangladesh. Mother-infant dyads. Over 80 % of 2178 pregnant women intended to exclusively breast-feed (EBF). Maternal positive attitudes, self-efficacy and knowledge about breast-feeding were positively associated with EBF intention (all P<0.05). All mothers except one reported initiating breast-feeding and 99.6 % of children were still breast-fed at 3 months. According to 24 h dietary recalls, we categorized 985 (45.2 %) infants as EBF at 3 months (47.8 % among mothers with EBF intention; 31.7 % among mothers with no EBF intention; P<0.05) and 551 (25.3 %) infants as predominantly breast-fed at 3 months (24.2 % among mothers with EBF intention; 30.8 % among mothers with no EBF intention; P<0.05). Prenatal EBF intention was associated with EBF (OR=1.48, 95 % CI 1.14, 1.91) and with full breast-feeding (OR=1.34, 95 % CI 1.04, 1.72) at age 3 months. EBF at age 3 months was not associated with maternal breast-feeding knowledge, attitudes or self-efficacy. Despite widespread expressed maternal EBF intention and universal breast-feeding initiation, prevalence of both exclusive and full breast-feeding at 3 months remains lower than WHO recommendations. EBF intention predicts breast-feeding behaviours, suggesting the importance of prenatal counselling to improve infant feeding behaviours.

Grain Refinement of Freeform Fabricated Ti-6Al-4V Alloy Using Beam/Arc Modulation

NASA Technical Reports Server (NTRS)

Mitzner, Scott; Liu, Stephen; Domack, Marcia S.; Hafley, Robert A.

2012-01-01

Grain refinement can significantly improve the mechanical properties of freeform-fabricated Ti-6Al-4V alloy, promoting increased strength and enhanced isotropy compared with coarser grained material. Large beta-grains can lead to a segregated microstructure, in regard to both alpha-phase morphology and alpha-lath orientation. Beam modulation, which has been used in conventional fusion welding to promote grain refinement, is explored in this study for use in additive manufacturing processes including electron beam freeform fabrication (EBF(sup 3)) and gas-tungsten arc (GTA) deposition to alter solidification behavior and produce a refined microstructure. The dynamic molten pool size induced by beam modulation causes rapid heat flow variance and results in a more competitive grain growth environment, reducing grain size. Consequently, improved isotropy and strength can be achieved with relatively small adjustments to deposition parameters.

Exclusive breastfeeding and postnatal changes in maternal anthropometry.

PubMed

Okechukwu, A A; Okpe, E C; Okolo, A A

2009-12-01

To evaluate the impact of exclusive breastfeeding (EBFing) practice on maternal anthropometry during the first 6 months of birth. Measurement of weight, height, triceps skin-fold thickness (TST), and mid-arm circumference (MAC) was carried out in a matched cohort of women practicing EBFing and those using other methods of infant feeding (non-EBFing group) in the first six months after delivery. There were 322 women practicing EBFing and 205 in the non-EBFing group. Weight loss was significantly higher among the EBFing group than in the non-EBFing ones during the first six months of EBFing practice (4.13 Vs 1.06kg), p<0.05. This was primarily due to average weight loss of 3.43kg in EBFing mothers in the last 3-6 months of EBFing practice. There was also a significant loss in MAC in the EBFing mothers than in the non-EBFing one (2.78 Vs 0.75cm), (p<0.05). Whereas the non-EBFing group experienced an increase in their TST (2.12mm), the EBFing mothers had a mean net loss of -1.03mm, (p<0.05). A positive correlation was seen between the frequency ofbreastfeeding and maternal weight changes in the EBFing group ( r=0.56, p<0.05), same was also seen between frequency of breastfeeding and maternal changes in TST and MAC losses in the same group of mothers, (r = 0.08 for TST , and 0.28 for the MAC, p<0.05). The weight/height Z scores (WHZ), an index of thinness and body mass index (BMI) that determines the nutritional status of an individual however remained within normal limit for both groups of mothers despite their weight loss ( WHZ of 0.67, and BMI of 22.09 +/- 3.7 kg/m2) for EBFing mothers, and ( WHZ of 0.71 and BMI of 22.82 +/- 3.2 kg/m2) for the non- EBFing mothers. It was concluded that though EBFing enhances more maternal weight loss, the nutritional status of the women practicing it however remained normal limit despite their weight loss.

Mutations in EBF3 Disturb Transcriptional Profiles and Cause Intellectual Disability, Ataxia, and Facial Dysmorphism.

PubMed

Harms, Frederike Leonie; Girisha, Katta M; Hardigan, Andrew A; Kortüm, Fanny; Shukla, Anju; Alawi, Malik; Dalal, Ashwin; Brady, Lauren; Tarnopolsky, Mark; Bird, Lynne M; Ceulemans, Sophia; Bebin, Martina; Bowling, Kevin M; Hiatt, Susan M; Lose, Edward J; Primiano, Michelle; Chung, Wendy K; Juusola, Jane; Akdemir, Zeynep C; Bainbridge, Matthew; Charng, Wu-Lin; Drummond-Borg, Margaret; Eldomery, Mohammad K; El-Hattab, Ayman W; Saleh, Mohammed A M; Bézieau, Stéphane; Cogné, Benjamin; Isidor, Bertrand; Küry, Sébastien; Lupski, James R; Myers, Richard M; Cooper, Gregory M; Kutsche, Kerstin

2017-01-05

From a GeneMatcher-enabled international collaboration, we identified ten individuals affected by intellectual disability, speech delay, ataxia, and facial dysmorphism and carrying a deleterious EBF3 variant detected by whole-exome sequencing. One 9-bp duplication and one splice-site, five missense, and two nonsense variants in EBF3 were found; the mutations occurred de novo in eight individuals, and the missense variant c.625C>T (p.Arg209Trp) was inherited by two affected siblings from their healthy mother, who is mosaic. EBF3 belongs to the early B cell factor family (also known as Olf, COE, or O/E) and is a transcription factor involved in neuronal differentiation and maturation. Structural assessment predicted that the five amino acid substitutions have damaging effects on DNA binding of EBF3. Transient expression of EBF3 mutant proteins in HEK293T cells revealed mislocalization of all but one mutant in the cytoplasm, as well as nuclear localization. By transactivation assays, all EBF3 mutants showed significantly reduced or no ability to activate transcription of the reporter gene CDKN1A, and in situ subcellular fractionation experiments demonstrated that EBF3 mutant proteins were less tightly associated with chromatin. Finally, in RNA-seq and ChIP-seq experiments, EBF3 acted as a transcriptional regulator, and mutant EBF3 had reduced genome-wide DNA binding and gene-regulatory activity. Our findings demonstrate that variants disrupting EBF3-mediated transcriptional regulation cause intellectual disability and developmental delay and are present in ∼0.1% of individuals with unexplained neurodevelopmental disorders. Copyright © 2017 American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

A Syndromic Neurodevelopmental Disorder Caused by De Novo Variants in EBF3.

PubMed

Chao, Hsiao-Tuan; Davids, Mariska; Burke, Elizabeth; Pappas, John G; Rosenfeld, Jill A; McCarty, Alexandra J; Davis, Taylor; Wolfe, Lynne; Toro, Camilo; Tifft, Cynthia; Xia, Fan; Stong, Nicholas; Johnson, Travis K; Warr, Coral G; Yamamoto, Shinya; Adams, David R; Markello, Thomas C; Gahl, William A; Bellen, Hugo J; Wangler, Michael F; Malicdan, May Christine V

2017-01-05

Early B cell factor 3 (EBF3) is a member of the highly evolutionarily conserved Collier/Olf/EBF (COE) family of transcription factors. Prior studies on invertebrate and vertebrate animals have shown that EBF3 homologs are essential for survival and that loss-of-function mutations are associated with a range of nervous system developmental defects, including perturbation of neuronal development and migration. Interestingly, aristaless-related homeobox (ARX), a homeobox-containing transcription factor critical for the regulation of nervous system development, transcriptionally represses EBF3 expression. However, human neurodevelopmental disorders related to EBF3 have not been reported. Here, we describe three individuals who are affected by global developmental delay, intellectual disability, and expressive speech disorder and carry de novo variants in EBF3. Associated features seen in these individuals include congenital hypotonia, structural CNS malformations, ataxia, and genitourinary abnormalities. The de novo variants affect a single conserved residue in a zinc finger motif crucial for DNA binding and are deleterious in a fly model. Our findings indicate that mutations in EBF3 cause a genetic neurodevelopmental syndrome and suggest that loss of EBF3 function might mediate a subset of neurologic phenotypes shared by ARX-related disorders, including intellectual disability, abnormal genitalia, and structural CNS malformations. Copyright © 2017 American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

Apple EIN3 BINDING F-box 1 inhibits the activity of three apple EIN3-like transcription factors

PubMed Central

Tacken, Emma J.; Ireland, Hilary S.; Wang, Yen-Yi; Putterill, Jo; Schaffer, Robert J.

2012-01-01

Background and aims Fruit ripening in Malus× domestica (apple) is controlled by ethylene. Work in model species has shown that following the detection of ethylene, the ETHYLENE INSENSITIVE 3 (EIN3) transcription factor is stabilized, leading to an increase in transcript accumulation of ethylene-responsive genes, such as POLYGALACTURONASE1 (PG1). In the absence of ethylene, the EIN3 BINDING F-box (EBF) proteins rapidly degrade EIN3 via the ubiquitination/SCF (Skp, Cullin, F-Box) proteasome pathway. In this study, we aim to identify and characterize the apple EBF genes, and test their activity against apple EIN3-like proteins (EILs). Methodology The apple genome sequence was mined for EBF-like genes. The expression of EBF-like genes was measured during fruit development. Using a transient assay in Nicotiana benthamiana leaves, the activity of three apple EILs was tested against the PG1 promoter, with and without ethylene and EBF1. Principal results Four EBF-like genes in apple were identified and grouped into two sub-clades. Sub-clade I genes had constant expression over fruit development while sub-clade II genes increased in expression at ripening. EBF1 was shown to reduce the transactivation of the apple PG1 promoter by the EIL1, EIL2 and EIL3 transcription factors in the presence of ethylene. Conclusions The apple EBF1 gene identified here is likely to be a functionally conserved EBF orthologue, modulating EIL activity in apples. The activity of EBF1 suggests that it is not specific to a single EIL, instead acting as a global regulator of apple EIL transcription factors. PMID:23585922

Exclusive breastfeeding practices in relation to social and health determinants: a comparison of the 2006 and 2011 Nepal Demographic and Health Surveys

PubMed Central

2013-01-01

Background Exclusive breastfeeding (EBF) for the first six months can have a significant impact on reducing child morbidity and mortality rates. The objective of this study was to compare the determinants of and trends in EBF in infants ≤5 months from the 2006 and 2011 Nepal Demographic and Health Surveys. Methods Data on mother/infant pairs having infants of ≤5 months from 2006 (n = 482) and 2011 (n = 227) were analysed. The EBF rate, determinants of EBF, and changes in EBF rates between the 2006 and 2011 surveys were examined using Chi-square test and multiple logistic regression. Results The EBF rate for ≤5 months in 2006 was 53.2% (95% CI, 47.1%-59.3%) and 66.3% (95% CI, 56.6%-74.8%) in 2011. In 2006, infants ≤4 months were more likely to be EBF [(aOR) 3.086, 95% CI (1.825-5.206)] after controlling for other factors. A geographic effect was also found in this study, with the odds of EBF higher for infants from the Hills [aOR 3.426, 95% CI (1.568-7.474)] compared to those form the mountains. The odds of EBF were also higher for higher order infants [aOR 1.968, 95% CI (1.020-3.799)]. Infants whose fathers belonged to non-agricultural occupation were less likely to be provided with EBF. Infants who were delivered in the home were more likely to experience EBF [aOR 1.886; 95% CI (1.044-3.407)]. In 2011, infants of age ≤4 months were more likely [aOR 4.963, 95% CI (2.317-10.629)] to have been breastfed exclusively. While there was an increase in the EBF rate between 2006 and 2011 surveys, the significant increase was noticed only among the infants of four months [32.0%; 95% CI (19.9%-47.0%)] in 2006 to [65.5%; 95% CI (48.1-79.6)] in 2011. Conclusions The proportion of infants who were EBF was higher in Nepal in 2011survey compared to 2006 survey; however, this is still below the recommended WHO target of 90%. Infant’s age, ecological region, parity and father’s occupation were associated with EBF. Further interventions such as peer counselling, antenatal counselling and involving fathers in the community to promote EBF in Nepal are recommended. PMID:24125095

Genome-wide methylation sequencing of paired primary and metastatic cell lines identifies common DNA methylation changes and a role for EBF3 as a candidate epigenetic driver of melanoma metastasis

PubMed Central

Chatterjee, Aniruddha; Stockwell, Peter A; Ahn, Antonio; Rodger, Euan J; Leichter, Anna L; Eccles, Michael R

2017-01-01

Epigenetic alterations are increasingly implicated in metastasis, whereas very few genetic mutations have been identified as authentic drivers of cancer metastasis. Yet, to date, few studies have identified metastasis-related epigenetic drivers, in part because a framework for identifying driver epigenetic changes in metastasis has not been established. Using reduced representation bisulfite sequencing (RRBS), we mapped genome-wide DNA methylation patterns in three cutaneous primary and metastatic melanoma cell line pairs to identify metastasis-related epigenetic drivers. Globally, metastatic melanoma cell lines were hypomethylated compared to the matched primary melanoma cell lines. Using whole genome RRBS we identified 75 shared (10 hyper- and 65 hypomethylated) differentially methylated fragments (DMFs), which were associated with 68 genes showing significant methylation differences. One gene, Early B Cell Factor 3 (EBF3), exhibited promoter hypermethylation in metastatic cell lines, and was validated with bisulfite sequencing and in two publicly available independent melanoma cohorts (n = 40 and 458 melanomas, respectively). We found that hypermethylation of the EBF3 promoter was associated with increased EBF3 mRNA levels in metastatic melanomas and subsequent inhibition of DNA methylation reduced EBF3 expression. RNAi-mediated knockdown of EBF3 mRNA levels decreased proliferation, migration and invasion in primary and metastatic melanoma cell lines. Overall, we have identified numerous epigenetic changes characterising metastatic melanoma cell lines, including EBF3-induced aggressive phenotypic behaviour with elevated EBF3 expression in metastatic melanoma, suggesting that EBF3 promoter hypermethylation may be a candidate epigenetic driver of metastasis. PMID:28030832

Finite Element Models for Electron Beam Freeform Fabrication Process

NASA Technical Reports Server (NTRS)

Chandra, Umesh

2012-01-01

Electron beam freeform fabrication (EBF3) is a member of an emerging class of direct manufacturing processes known as solid freeform fabrication (SFF); another member of the class is the laser deposition process. Successful application of the EBF3 process requires precise control of a number of process parameters such as the EB power, speed, and metal feed rate in order to ensure thermal management; good fusion between the substrate and the first layer and between successive layers; minimize part distortion and residual stresses; and control the microstructure of the finished product. This is the only effort thus far that has addressed computer simulation of the EBF3 process. The models developed in this effort can assist in reducing the number of trials in the laboratory or on the shop floor while making high-quality parts. With some modifications, their use can be further extended to the simulation of laser, TIG (tungsten inert gas), and other deposition processes. A solid mechanics-based finite element code, ABAQUS, was chosen as the primary engine in developing these models whereas a computational fluid dynamics (CFD) code, Fluent, was used in a support role. Several innovative concepts were developed, some of which are highlighted below. These concepts were implemented in a number of new computer models either in the form of stand-alone programs or as user subroutines for ABAQUS and Fluent codes. A database of thermo-physical, mechanical, fluid, and metallurgical properties of stainless steel 304 was developed. Computing models for Gaussian and raster modes of the electron beam heat input were developed. Also, new schemes were devised to account for the heat sink effect during the deposition process. These innovations, and others, lead to improved models for thermal management and prediction of transient/residual stresses and distortions. Two approaches for the prediction of microstructure were pursued. The first was an empirical approach involving the computation of thermal gradient, solidification rate, and velocity (G,R,V) coupled with the use of a solidification map that should be known a priori. The second approach relies completely on computer simulation. For this purpose a criterion for the prediction of morphology was proposed, which was combined with three alternative models for the prediction of microstructure; one based on solidification kinetics, the second on phase diagram, and the third on differential scanning calorimetry data. The last was found to be the simplest and the most versatile; it can be used with multicomponent alloys and rapid solidification without any additional difficulty. For the purpose of (limited) experimental validation, finite element models developed in this effort were applied to three different shapes made of stainless steel 304 material, designed expressly for this effort with an increasing level of complexity. These finite element models require large computation time, especially when applied to deposits with multiple adjacent beads and layers. This problem can be overcome, to some extent, by the use of fast, multi-core computers. Also, due to their numerical nature coupled with the fact that solid mechanics- based models are being used to represent the material behavior in liquid and vapor phases as well, the models have some inherent approximations that become more pronounced when dealing with multi-bead and multi-layer deposits.

Novel de novo variant in EBF3 is likely to impact DNA binding in a patient with a neurodevelopmental disorder and expanded phenotypes: patient report, in silico functional assessment, and review of published cases.

PubMed

Blackburn, Patrick R; Barnett, Sarah S; Zimmermann, Michael T; Cousin, Margot A; Kaiwar, Charu; Pinto E Vairo, Filippo; Niu, Zhiyv; Ferber, Matthew J; Urrutia, Raul A; Selcen, Duygu; Klee, Eric W; Pichurin, Pavel N

2017-05-01

Pathogenic variants in EBF3 were recently described in three back-to-back publications in association with a novel neurodevelopmental disorder characterized by intellectual disability, speech delay, ataxia, and facial dysmorphisms. In this report, we describe an additional patient carrying a de novo missense variant in EBF3 (c.487C>T, p.(Arg163Trp)) that falls within a conserved residue in the zinc knuckle motif of the DNA binding domain. Without a solved structure of the DNA binding domain, we generated a homology-based atomic model and performed molecular dynamics simulations for EBF3, which predicted decreased DNA affinity for p.(Arg163Trp) compared with wild-type protein and control variants. These data are in agreement with previous experimental studies of EBF1 showing the paralogous residue is essential for DNA binding. The conservation and experimental evidence existing for EBF1 and in silico modeling and dynamics simulations to validate comparable behavior of multiple variants in EBF3 demonstrates strong support for the pathogenicity of p.(Arg163Trp). We show that our patient presents with phenotypes consistent with previously reported patients harboring EBF3 variants and expands the phenotypic spectrum of this newly identified disorder with the additional feature of a bicornuate uterus.

PIF3 is a negative regulator of the CBF pathway and freezing tolerance in Arabidopsis

PubMed Central

Jiang, Bochen; Shi, Yiting; Zhang, Xiaoyan; Xin, Xiaoyun; Qi, Lijuan; Guo, Hongwei; Li, Jigang; Yang, Shuhua

2017-01-01

Light and temperature are major environmental factors that coordinately control plant growth and survival. However, how plants integrate light and temperature signals to better adapt to environmental stresses is poorly understood. PHYTOCHROME-INTERACTING FACTOR 3 (PIF3), a key transcription factor repressing photomorphogenesis, has been shown to play a pivotal role in mediating plants’ responses to various environmental signals. In this study, we found that PIF3 functions as a negative regulator of Arabidopsis freezing tolerance by directly binding to the promoters of C-REPEAT BINDING FACTOR (CBF) genes to down-regulate their expression. In addition, two F-box proteins, EIN3-BINDING F-BOX 1 (EBF1) and EBF2, directly target PIF3 for 26S proteasome-mediated degradation. Consistently, ebf1 and ebf2 mutants were more sensitive to freezing than were the wild type, and the pif3 mutation suppressed the freezing-sensitive phenotype of ebf1. Furthermore, cold treatment promoted the degradation of EBF1 and EBF2, leading to increased stability of the PIF3 protein and reduced expression of the CBF genes. Together, our study uncovers an important role of PIF3 in Arabidopsis freezing tolerance by negatively regulating the expression of genes in the CBF pathway. PMID:28739888

De novo variants in EBF3 are associated with hypotonia, developmental delay, intellectual disability, and autism

PubMed Central

Tanaka, Akemi J.; Cho, Megan T.; Willaert, Rebecca; Retterer, Kyle; Zarate, Yuri A.; Bosanko, Katie; Stefans, Vikki; Oishi, Kimihiko; Williamson, Amy; Wilson, Golder N.; Basinger, Alice; Barbaro-Dieber, Tina; Ortega, Lucia; Sorrentino, Susanna; Gabriel, Melissa K.; Anderson, Ilse J.; Sacoto, Maria J. Guillen; Schnur, Rhonda E.; Chung, Wendy K.

2017-01-01

Using whole-exome sequencing, we identified seven unrelated individuals with global developmental delay, hypotonia, dysmorphic facial features, and an increased frequency of short stature, ataxia, and autism with de novo heterozygous frameshift, nonsense, splice, and missense variants in the Early B-cell Transcription Factor Family Member 3 (EBF3) gene. EBF3 is a member of the collier/olfactory-1/early B-cell factor (COE) family of proteins, which are required for central nervous system (CNS) development. COE proteins are highly evolutionarily conserved and regulate neuronal specification, migration, axon guidance, and dendritogenesis during development and are essential for maintaining neuronal identity in adult neurons. Haploinsufficiency of EBF3 may affect brain development and function, resulting in developmental delay, intellectual disability, and behavioral differences observed in individuals with a deleterious variant in EBF3. PMID:29162653

What works to improve duration of exclusive breastfeeding: lessons from the exclusive breastfeeding promotion program in rural Indonesia.

PubMed

Susiloretni, Kun Aristiati; Hadi, Hamam; Prabandari, Yayi Suryo; Soenarto, Yati S; Wilopo, Siswanto Agus

2015-07-01

The aim of the study was to identify determinants of exclusive breastfeeding (EBF) at the individual, family, community, and organizational level. This study was a secondary analysis of data from a multilevel promotion of EBF program in two rural public health centers (PHCs) in the Demak district, Central Java, Indonesia. The program was a quasi-experimental study with a pretest-posttest control group. A total of 599 participants were enrolled, consisting of 163 mother infant pairs, 163 fathers, 163 grandmothers, 82 community leaders, and 28 midwives. EBF duration and its determinants were measured and analyzed using Cox proportional-hazard model. Mothers with a high level of breastfeeding knowledge had the greatest EBF duration. Mothers who had a knowledge score >80 had a 73 % (HR 0.27, 95 % CI 0.15, 0.48) greater chance of EBF compared to mothers who had a knowledge score of <60. Factors which shortened EBF duration were grandmother's lack of support for EBF (HR 2.04, 95 % CI 1.33, 3.14), received formula samples at discharge (HR 1.99, 95 % CI 1.25, 3.16), and maternal experience of breast engorgement (HR 1.97, 95 % CI 1.32, 2.94). High maternal breastfeeding knowledge was the only factor associated with longer duration of EBF. Barriers to EBF were breast engorgement, receiving formula samples at discharge, and a grandmother's lack of support for EBF.

De novo variants in EBF3 are associated with hypotonia, developmental delay, intellectual disability, and autism.

PubMed

Tanaka, Akemi J; Cho, Megan T; Willaert, Rebecca; Retterer, Kyle; Zarate, Yuri A; Bosanko, Katie; Stefans, Vikki; Oishi, Kimihiko; Williamson, Amy; Wilson, Golder N; Basinger, Alice; Barbaro-Dieber, Tina; Ortega, Lucia; Sorrentino, Susanna; Gabriel, Melissa K; Anderson, Ilse J; Sacoto, Maria J Guillen; Schnur, Rhonda E; Chung, Wendy K

2017-11-01

Using whole-exome sequencing, we identified seven unrelated individuals with global developmental delay, hypotonia, dysmorphic facial features, and an increased frequency of short stature, ataxia, and autism with de novo heterozygous frameshift, nonsense, splice, and missense variants in the Early B-cell Transcription Factor Family Member 3 ( EBF3 ) gene. EBF3 is a member of the collier/olfactory-1/early B-cell factor (COE) family of proteins, which are required for central nervous system (CNS) development. COE proteins are highly evolutionarily conserved and regulate neuronal specification, migration, axon guidance, and dendritogenesis during development and are essential for maintaining neuronal identity in adult neurons. Haploinsufficiency of EBF3 may affect brain development and function, resulting in developmental delay, intellectual disability, and behavioral differences observed in individuals with a deleterious variant in EBF3 . © 2017 Tanaka et al.; Published by Cold Spring Harbor Laboratory Press.

EBF proteins participate in transcriptional regulation of Xenopus muscle development.

PubMed

Green, Yangsook Song; Vetter, Monica L

2011-10-01

EBF proteins have diverse functions in the development of multiple lineages, including neurons, B cells and adipocytes. During Drosophila muscle development EBF proteins are expressed in muscle progenitors and are required for muscle cell differentiation, but there is no known function of EBF proteins in vertebrate muscle development. In this study, we examine the expression of ebf genes in Xenopus muscle tissue and show that EBF activity is necessary for aspects of Xenopus skeletal muscle development, including somite organization, migration of hypaxial muscle anlagen toward the ventral abdomen, and development of jaw muscle. From a microarray screen, we have identified multiple candidate targets of EBF activity with known roles in muscle development. The candidate targets we have verified are MYOD, MYF5, M-Cadherin and SEB-4. In vivo overexpression of the ebf2 and ebf3 genes leads to ectopic expression of these candidate targets, and knockdown of EBF activity causes downregulation of the endogenous expression of the candidate targets. Furthermore, we found that MYOD and MYF5 are likely to be direct targets. Finally we show that MYOD can upregulate the expression of ebf genes, indicating the presence of a positive feedback loop between EBF and MYOD that we find to be important for maintenance of MYOD expression in Xenopus. These results suggest that EBF activity is important for both stabilizing commitment and driving aspects of differentiation in Xenopus muscle cells. Copyright © 2010 Elsevier Inc. All rights reserved.

Predictors of exclusive breastfeeding across three time points in Bangladesh: an examination of the 2007, 2011 and 2014 Demographic and Health Survey.

PubMed

Blackstone, Sarah R; Sanghvi, Tina

2018-05-01

The objective of this study was to explore predictors of exclusive breastfeeding (EBF) in Bangladesh using data from 2007, 2011 and 2014, specifically focusing on potential reasons why rates of EBF changed over those time periods. Data on mother/infant pairs with infants <6 months of age were examined at the three time points using the Bangladesh Demographic and Health Survey. The EBF prevalence, changes in EBF since the previous survey and determinants of EBF at each time period were examined using t-tests, χ2 and multilevel logistic regression. The prevalence of EBF was 42.5, 65 and 59.4% in 2007, 2011 and 2014, respectively. The age of the child was significantly associated with EBF across all time points. The largest changes in EBF occurred in the 3- to 5-month age group. Predictors of EBF in this specific age group were similar to overall predictors (e.g. age of the child and region). Participation of the mother in household decisions was a significant predictor in 2014. EBF prevalence in Bangladesh increased between 2007 and 2011 and then decreased between 2011 and 2014. The increase in 2011 may have been the result of widespread initiatives to promote EBF in that time frame. Due to the unexplained decrease in EBF between 2011 and 2014, there is still a need for interventions such as peer counselling, antenatal education and community awareness to promote EBF.

Factors influencing adherence to exclusive breast feeding among HIV positive mothers in Kabarole district, Uganda.

PubMed

Matovu, A; Kirunda, B; Rugamba-Kabagambe, G; Tumwesigye, N M; Nuwaha, F

2008-04-01

To identify the factors influencing adherence to exclusive breast feeding (EBF) among HIV positive mothers in Kabarole district, Uganda. Cross-sectional study. Kabarore district, western Uganda. HIV infected women attending for psychosocial support that adhered or did not adhere to EBF. We compared personal factors, influence from other people, barriers and supports towards adherence to EBF among 139 HIV infected women who adhered and among 139 women who did not adhere to EBF using univariate and multivariate analyses. The independent predictors of adherence to EBF are: having formal education (Adjusted Odds Ratio [AOR] 2.21, 95% confidence interval [CI] 1.01-4.84), knowledge of EBF as a method of preventing mother to child transmission of HIV (AOR 2.53, CI 1.11-5.75), attending at least four antenatal infant feeding counselling sessions (AOR 3.86, CI 1.82-8.19), attending at least six postnatal counselling sessions (AOR 12.52, CI 3.89-40.30), health workers being consulted for breastfeeding problems (AOR 13.11, CI 3.75-45.81), mothers thinking that they are able to produce enough milk (AOR 3.92, CI 1.74-8.84), initiation of breastfeeding within one hour of birth (AOR 10.17, CI 4.52-22.88), getting support from the father to EBF (AOR 5.27, CI 1.87-14.81) and getting support from the family to EBF (AOR 4.54, CI 2.09-9.84). In order to improve adherence to EBF there is need to: involve the family especially fathers in infant feeding counselling and education, target less educated mothers for more intense infant feeding counselling using appropriate methods, intensify education on benefits of EBF and on how to produce enough milk and to encourage mothers to attend regularly for ante-natal and post-natal care.

The EB factory project. II. Validation with the Kepler field in preparation for K2 and TESS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Parvizi, Mahmoud; Paegert, Martin; Stassun, Keivan G., E-mail: mahmoud.parvizi@vanderbilt.edu

Large repositories of high precision light curve data, such as the Kepler data set, provide the opportunity to identify astrophysically important eclipsing binary (EB) systems in large quantities. However, the rate of classical “by eye” human analysis restricts complete and efficient mining of EBs from these data using classical techniques. To prepare for mining EBs from the upcoming K2 mission as well as other current missions, we developed an automated end-to-end computational pipeline—the Eclipsing Binary Factory (EBF)—that automatically identifies EBs and classifies them into morphological types. The EBF has been previously tested on ground-based light curves. To assess the performancemore » of the EBF in the context of space-based data, we apply the EBF to the full set of light curves in the Kepler “Q3” Data Release. We compare the EBs identified from this automated approach against the human generated Kepler EB Catalog of ∼2600 EBs. When we require EB classification with ⩾90% confidence, we find that the EBF correctly identifies and classifies eclipsing contact (EC), eclipsing semi-detached (ESD), and eclipsing detached (ED) systems with a false positive rate of only 4%, 4%, and 8%, while complete to 64%, 46%, and 32%, respectively. When classification confidence is relaxed, the EBF identifies and classifies ECs, ESDs, and EDs with a slightly higher false positive rate of 6%, 16%, and 8%, while much more complete to 86%, 74%, and 62%, respectively. Through our processing of the entire Kepler “Q3” data set, we also identify 68 new candidate EBs that may have been missed by the human generated Kepler EB Catalog. We discuss the EBF's potential application to light curve classification for periodic variable stars more generally for current and upcoming surveys like K2 and the Transiting Exoplanet Survey Satellite.« less

The Eb Factory Project. Ii. Validation With the Kepler Field in Preparation for K2 and Tess

NASA Astrophysics Data System (ADS)

Parvizi, Mahmoud; Paegert, Martin; Stassun, Keivan G.

2014-12-01

Large repositories of high precision light curve data, such as the Kepler data set, provide the opportunity to identify astrophysically important eclipsing binary (EB) systems in large quantities. However, the rate of classical “by eye” human analysis restricts complete and efficient mining of EBs from these data using classical techniques. To prepare for mining EBs from the upcoming K2 mission as well as other current missions, we developed an automated end-to-end computational pipeline—the Eclipsing Binary Factory (EBF)—that automatically identifies EBs and classifies them into morphological types. The EBF has been previously tested on ground-based light curves. To assess the performance of the EBF in the context of space-based data, we apply the EBF to the full set of light curves in the Kepler “Q3” Data Release. We compare the EBs identified from this automated approach against the human generated Kepler EB Catalog of ˜ 2600 EBs. When we require EB classification with ≥slant 90% confidence, we find that the EBF correctly identifies and classifies eclipsing contact (EC), eclipsing semi-detached (ESD), and eclipsing detached (ED) systems with a false positive rate of only 4%, 4%, and 8%, while complete to 64%, 46%, and 32%, respectively. When classification confidence is relaxed, the EBF identifies and classifies ECs, ESDs, and EDs with a slightly higher false positive rate of 6%, 16%, and 8%, while much more complete to 86%, 74%, and 62%, respectively. Through our processing of the entire Kepler “Q3” data set, we also identify 68 new candidate EBs that may have been missed by the human generated Kepler EB Catalog. We discuss the EBF's potential application to light curve classification for periodic variable stars more generally for current and upcoming surveys like K2 and the Transiting Exoplanet Survey Satellite.

Exclusive breastfeeding practices in working women of Pakistan: A cross sectional study.

PubMed

Sabin, Aroona; Manzur, Farida; Adil, Saleem

2017-01-01

To determine the prevalence of exclusive breast feeding in working women and to identify the factors effecting exclusive breast feeding in working women. This cross-sectional survey was conducted in Faisalabad city within a period of six months from June 2016 to December 2016. Working women of age 18 to 45 years, working as doctors, teachers, nurses and bankers in public (government) setup were included. The data was collected using interview method by pre-structured questionnaire. Multi-variable logistic regression model was developed considering EBF practice as dependent and the significant independent variables. Results were reported as Crude Odds Ratio (COR) or Adjusted Odds Ratio (AOR) with 95% Confidence Intervals (CIs). Prevalence of exclusive breast feeding (EBF) was 166 (41.5%). EFB practice was significantly less in doctors and bankers as compared to nurses and teachers (p-value <0.001). Women working as nurses and teachers, having one or two children and short working hours had higher prevalence of exclusive breast feeding. Women having prior knowledge about EBF, training of EBF and women who had previously heard about EBF had five time higher rate of breast feeding. Women having knowledge of colostrum had three times higher EBF practice [odds ratio: 3.02 (1.86-4.91)]. Women having knowledge about hazards of bottle feeding had 12.7 times higher prevalence of EBF [odds ratio: 12.72 (5.70-28.38)]. Those who knew about expression of breast milk had three times higher prevalence of EBF [odds ratio: 3.0 (1.98-4.55)]. Mothers working in organizations that support EBF had 4.1 times higher prevalence of EBF [odds ratio: 4.1 (2.67-6.21)]. And proper training of mothers about correct expression technique of breast milk had 12 time [odds ratio: 12.06 (4.97-29.23)] higher prevalence of EBF. Long working hours, banking profession, family income and lack of proper knowledge about exclusive breast feeding are responsible for non-EBF practice in working women. Proper Knowledge and awareness about exclusive breastfeeding and provision of facilities for exclusive breastfeeding (EBF) by the organizations can play a significant role in promoting it.

Identification of an intraspecific alarm pheromone and two conserved odorant-binding proteins associated with (E)-β-farnesene perception in aphid Rhopalosiphum padi.

PubMed

Fan, Jia; Xue, Wenxin; Duan, Hongxia; Jiang, Xin; Zhang, Yong; Yu, Wenjuan; Jiang, Shanshan; Sun, Jingrun; Chen, Julian

2017-08-01

(E)-β-farnesene (EBF) is the common active component of aphid alarm pheromone. Either or both of two orthologs of ordorant-binding proteins (OBPs), OBP3 and OBP7, recently reported in aphids, may be involved in EBF perception. The aim of this study was to investigate the respondence of the aphid Rhopalosiphum padi to its intraspecific alarm pheromone and which OBP is responsible for that response. We tested the olfactory response of the aphid R. padi to EBF and freshly crushed aphids. Then, we extracted the volatiles from crushed aphids using solid phase microextraction (SPME) for analysis with GC×GC-TOF/MS. We also cloned two OBPs cDNAs in R. padi (RpadOBP3 and RpadOBP7) and expressed them in competent Escherichia coli cells. Both recombinant proteins, RpadOBP3 and RpadOBP7, bound EBF well, with RpadOBP7 having specifically stronger affinity for EBF than for other volatiles. Based on the crystal structure of the OBPs with high identity, we performed homology modeling and analyzed the interactions between RpadOBPs and EBF. In conclusion, R. padi was repelled by both EBF and crushed aphids. EBF was identified as the only volatile that acted as the alarm pheromone. Our results indicated that OBP7 is a potential molecular target to control wheat aphids by disturbing their behaviors to the alarm pheromone. Copyright © 2017 Elsevier Ltd. All rights reserved.

The Red Light Receptor Phytochrome B Directly Enhances Substrate-E3 Ligase Interactions to Attenuate Ethylene Responses.

PubMed

Shi, Hui; Shen, Xing; Liu, Renlu; Xue, Chang; Wei, Ning; Deng, Xing Wang; Zhong, Shangwei

2016-12-05

Plants germinating under subterranean darkness assume skotomorphogenesis, a developmental program strengthened by ethylene in response to mechanical pressure of soil. Upon reaching the surface, light triggers a dramatic developmental transition termed de-etiolation that requires immediate termination of ethylene responses. Here, we report that light activation of photoreceptor phyB results in rapid degradation of EIN3, the master transcription factor in the ethylene signaling pathway. As a result, light rapidly and efficiently represses ethylene actions. Specifically, phyB directly interacts with EIN3 in a light-dependent manner and also physically associates with F box protein EBFs. The light-activated association of phyB, EIN3, and EBF1/EBF2 proteins stimulates robust EIN3 degradation by SCF EBF1/EBF2 E3 ligases. We reveal that phyB manipulates substrate-E3 ligase interactions in a light-dependent manner, thus directly controlling the stability of EIN3. Our findings illustrate a mechanistic model of how plants transduce light information to immediately turn off ethylene signaling for de-etiolation initiation. Copyright © 2016 Elsevier Inc. All rights reserved.

Laboratory testing of extravascular body fluids in Croatia: a survey of the Working group for extravascular body fluids of the Croatian Society of Medical Biochemistry and Laboratory Medicine.

PubMed

Kopcinovic, Lara Milevoj; Vogrinc, Zeljka; Kocijan, Irena; Culej, Jelena; Aralica, Merica; Jokic, Anja; Antoncic, Dragana; Bozovic, Marija

2016-10-15

We hypothesized that extravascular body fluid (EBF) analysis in Croatia is not harmonized and aimed to investigate preanalytical, analytical and postanalytical procedures used in EBF analysis in order to identify key aspects that should be addressed in future harmonization attempts. An anonymous online survey created to explore laboratory testing of EBF was sent to secondary, tertiary and private health care Medical Biochemistry Laboratories (MBLs) in Croatia. Statements were designed to address preanalytical, analytical and postanalytical procedures of cerebrospinal, pleural, peritoneal (ascites), pericardial, seminal, synovial, amniotic fluid and sweat. Participants were asked to declare the strength of agreement with proposed statements using a Likert scale. Mean scores for corresponding separate statements divided according to health care setting were calculated and compared. The survey response rate was 0.64 (58 / 90). None of the participating private MBLs declared to analyse EBF. We report a mean score of 3.45 obtained for all statements evaluated. Deviations from desirable procedures were demonstrated in all EBF testing phases. Minor differences in procedures used for EBF analysis comparing secondary and tertiary health care MBLs were found. The lowest scores were obtained for statements regarding quality control procedures in EBF analysis, participation in proficiency testing programmes and provision of interpretative comments on EBF's test reports. Although good laboratory EBF practice is present in Croatia, procedures for EBF analysis should be further harmonized to improve the quality of EBF testing and patient safety.

Women׳s intention to exclusively breast feed: The Israeli perspective.

PubMed

Ben Natan, Merav; Wiener, Alina; Ben Haim, Yarden

2016-03-01

research reveals that there are numerous factors related to women׳s intention to exclusively breast feed (EBF). Moreover, several studies do not differentiate between exclusive and partial breast feeding. the aim of the present study was to identify factors associated with Israeli women׳s intention to EBF their next baby based on the Theory of Planned Behavior (TPB), within the context of Israeli ethnic and cultural diversity. the study is a correlational quantitative study. women were recruited at lectures on women׳s health at an urban setting in central Israel during September-December 2013. The lectures were organised by a local nursing school and were open for the general public. a convenience sample of 200 Hebrew-speaking women of childbearing age, who had at least one child over six months old which had been EBF for at least one month. the women completed a closed questionnaire based on the TPB. in the multivariate analysis, behavioural beliefs, behavioural attitudes, knowledge of EBF, and EBF duration of the previous child predicted 35.3% of Israeli women׳s intentions to EBF in the future. In addition, study findings revealed the importance that women attributed to their spouses׳ opinion concerning EBF. Muslim Arab women expressed higher intention to EBF than Jewish women. the findings of this study will constitute the basis of a nurse-administered intervention programme for promoting EBF in Israeli society. In the context of this programme, nurses' interventions will emphasise the benefits of EBF for mothers and infants, and provide women and their spouses with tools and information to support EBF. Nurses' interventions will also take into account the influence of ethnicity and culture, as well as the duration of women's previous EBF experiences. Copyright © 2015 Elsevier Ltd. All rights reserved.

Duration of exclusive breast-feeding and infant iron and zinc status in rural Bangladesh.

PubMed

Eneroth, Hanna; El Arifeen, Shams; Persson, Lars-Ake; Kabir, Iqbal; Lönnerdal, Bo; Hossain, Mohammad Bakhtiar; Ekström, Eva-Charlotte

2009-08-01

There is a concern that exclusive breast-feeding (EBF) for 6 mo may lead to iron and zinc deficiency in low-birth weight (LBW) infants. We assessed the association between duration of EBF and infant iron and zinc status in the Maternal and Infant Nutrition Interventions in Matlab trial, Bangladesh, stratified for normal birth weigh (NBW) and LBW. Duration of EBF was classified into EBF <4 mo and EBF 4-6 mo based on monthly recalls of foods introduced to the infant. Blood samples collected at 6 mo were analyzed for plasma zinc (n = 1032), plasma ferritin (n = 1040), and hemoglobin (Hb) (n = 791). Infants EBF 4-6 mo had a higher mean plasma zinc concentration (9.9 +/- 2.3 micromol/L) than infants EBF <4mo (9.5 +/- 2.0 micromol/L) (P < 0.01). This association was apparent in only the NBW strata and was not reflected in a lower prevalence of zinc deficiency. Duration of EBF was not associated with concentration of plasma ferritin, Hb concentration, or prevalence of iron deficiency or anemia in any strata. Regardless of EBF duration, the prevalence of zinc deficiency, iron deficiency, and anemia was high in infants in this population and strategies to prevent deficiency are needed.

Exclusive breast feeding (EBF) in Jordan: prevalence, duration, practices, and barriers.

PubMed

Abuidhail, Jamila; Al-Modallal, Hanan; Yousif, Rania; Almresi, Neamat

2014-03-01

of this study is to investigate the prevalence, duration, practices and barriers of Exclusive breast feeding (EBF) among Jordanian mothers in three major governorates. longitudinal, prospective design was used in this study. convenience sample of 572 pairs of postpartum mothers-infants were recruited from postpartum wards at three governmental hospitals and three private hospitals in major Jordanian governorate. data were collected in two phases. In the first phase, trained research assistants conducted face to face structured interviews with participating mothers at the hospital. In the second phase, the research assistants conducted follow up phone interviews at the end of first, fourth and sixth months after birth. The findings of this study showed that the prevalence of EBF as recommended by WHO was 1%. The average duration of EBF was one month. The main barriers of EBF were: infants feel hungry after breast feeding, short period between pregnancies, and breast problems. postpartum mothers initiated EBF practice within the first hour after giving birth; however, this practice declined gradually as the infant grew up within the first six months after birth. antenatal education sessions in the Jordanian governmental hospitals about EBF are required to meet the WHO recommendations. Furthermore, midwives and nurses have to focus on effective breast feeding process to overcome the barriers of EBF during antenatal education and postnatal care. Copyright © 2013 Elsevier Ltd. All rights reserved.

High uptake of exclusive breastfeeding and reduced early post-natal HIV transmission.

PubMed

Kuhn, Louise; Sinkala, Moses; Kankasa, Chipepo; Semrau, Katherine; Kasonde, Prisca; Scott, Nancy; Mwiya, Mwiya; Vwalika, Cheswa; Walter, Jan; Tsai, Wei-Yann; Aldrovandi, Grace M; Thea, Donald M

2007-12-26

Empirical data showing the clear benefits of exclusive breastfeeding (EBF) for HIV prevention are needed to encourage implementation of lactation support programs for HIV-infected women in low resource settings among whom replacement feeding is unsafe. We conducted a prospective, observational study in Lusaka, Zambia, to test the hypothesis that EBF is associated with a lower risk of postnatal HIV transmission than non-EBF. As part of a randomized trial of early weaning, 958 HIV-infected women and their infants were recruited and all were encouraged to breastfeed exclusively to 4 months. Single-dose nevirapine was provided to prevent transmission. Regular samples were collected from infants to 24 months of age and tested by PCR. Detailed measurements of actual feeding behaviors were collected to examine, in an observational analysis, associations between feeding practices and postnatal HIV transmission. Uptake of EBF was high with 84% of women reporting only EBF cumulatively to 4 months. Post-natal HIV transmission before 4 months was significantly lower (p = 0.004) among EBF (0.040 95% CI: 0.024-0.055) than non-EBF infants (0.102 95% CI: 0.047-0.157); time-dependent Relative Hazard (RH) of transmission due to non-EBF = 3.48 (95% CI: 1.71-7.08). There were no significant differences in the severity of disease between EBF and non-EBF mothers and the association remained significant (RH = 2.68 95% CI: 1.28-5.62) after adjusting for maternal CD4 count, plasma viral load, syphilis screening results and low birth weight. Non-EBF more than doubles the risk of early postnatal HIV transmission. Programs to support EBF should be expanded universally in low resource settings. EBF is an affordable, feasible, acceptable, safe and sustainable practice that also reduces HIV transmission providing HIV-infected women with a means to protect their children's lives. ClinicalTrials.gov NCT00310726.

Variation of energy absorption and exposure buildup factors with incident photon energy and penetration depth for boro-tellurite (B2O3-TeO2) glasses

NASA Astrophysics Data System (ADS)

Sayyed, M. I.; Elhouichet, H.

2017-01-01

The gamma ray energy absorption (EABF) and exposure buildup factors (EBF) of (100-x)TeO2-xB2O3 glass systems (where x=5, 10, 15, 20, 22.5 and 25 mol%) have been calculated in the energy region 0.015-15 MeV up to a penetration depth of 40 mfp (mean free path). The five parameters (G-P) fitting method has been used to estimate both EABF and EBF values. Variations of EABF and EBF with incident photon energy and penetration depth have been studied. It was found that EABF and EBF values were higher in the intermediate energy region, for all the glass systems. Furthermore, boro-tellurite glass with 5 mol% B2O3, was found to present the lowest EABF and EBF values, hence it is superior gamma-ray shielding material. The results indicate that the boro-tellurite glasses can be used as radiation shielding materials.

Psychosocial factors underlying the mother's decision to continue exclusive breastfeeding for 6 months: an elicitation study.

PubMed

Bai, Y K; Middlestadt, S E; Joanne Peng, C-Y; Fly, A D

2009-04-01

Despite numerous benefits of exclusive breastfeeding (EBF) for infants and mothers, a significant decrease in the EBF rate in the USA at six months compared to the rate at birth suggests that reasons for initiation and continuation of EBF may differ. The purpose of this qualitative study was to explore psychosocial factors underlying the continued EBF behaviour for six months, in order to identify salient belief structures according to the theory of planned behaviour. Participants were recruited from central Indiana in the USA. They were asked to respond to an open-ended questionnaire designed to elicit positive/negative consequences, approving/disapproving social referents, and easy/difficult circumstances in continuing EBF for six months. Responses were translated into behavioural, normative, and control beliefs of the theory. Findings suggest that respondents (1) value emotional and health benefits of continued EBF for six months; (2) feel the approval from family and friends but disapproval from the society; (3) view health professional's position as positive and negative. Breastfeeding educators can more likely improve the EBF duration by addressing these salient beliefs. Identified beliefs provide a basis for the development of a quantitative instrument to further study the EBF behaviour.

Lactation counseling increases exclusive breast-feeding rates in Ghana.

PubMed

Aidam, Bridget A; Pérez-Escamilla, Rafael; Lartey, Anna

2005-07-01

Exclusive breast-feeding (EBF) rates remain low despite numerous health benefits associated with this behavior. We conducted a randomized trial on the effect of lactation counseling on EBF, which controlled for the Hawthorne effect while also varying the timing of the intervention. Pregnant women attending prenatal clinics in Tema were randomly assigned to 1 of 2 intervention groups (IG) or to a control group (C), as follows: 1) EBF support given pre-, peri-, and postnatally (IG1; n = 43); 2) EBF support given only peri- and postnatally (IG2; n = 44); or 3) nonbreast-feeding health educational support (C; n = 49) that had an equal amount of contact with lactation counselors. Two educational sessions were provided prenatally, and 9 home follow-up visits were provided in the 6-mo postpartum period. Infant feeding data were collected monthly at the participant's home. The 3 groups did not differ in sociodemographic characteristics. At 6 mo postpartum, 90.0% in IG1 and 74.4% in IG2 had exclusively breast-fed during the previous month. By contrast, only 47.7% in C were doing so (P = 0.008). Similarly, the percentage of EBF during the 6 mo was significantly higher (P = 0.02) among IG1 and IG2 (39.5%) than among C (19.6%). The 100% increase in EBF rates can be attributed to the lactation counseling provided. Additional prenatal EBF support may not be needed within a context of strong routine prenatal EBF education.

Predictors of exclusive breast-feeding in early infancy: a survey report from Phnom Penh, Cambodia.

PubMed

Sasaki, Yuri; Ali, Moazzam; Kakimoto, Kazuhiro; Saroeun, Ou; Kanal, Koum; Kuroiwa, Chushi

2010-12-01

Exclusive breast-feeding (EBF) is recommended in the first 6 months of an infant's life. This study aims to investigate the present status of infant feeding practices and identify factors that affect EBF practices during the first 6 months following infant birth in Phnom Penh, Cambodia. A cross-sectional survey with a semistructured questionnaire was given to 312 mothers with children aged 6 to 24 months who visited the immunization clinic in the National Maternal and Child Health Centre in Phnom Penh, Cambodia, from December 2005 to February 2006. Eighty-three percent of mothers fed breast milk exclusively in the first month, whereas only 51.3% continued EBF in the first 6 months. Within 30 minutes after delivery, 39% of mothers began breast-feeding. Results from logistic regression analysis indicate that the lack of a maternal antenatal EBF plan (odds ratio [OR] = 10.01, 95% confidence interval [CI] = 3.68-27.24, p < .001), working mothers (OR = 4.71, 95% CI = 2.77-8.01, p < .001), and lack of paternal attendance at breast-feeding classes (OR = 1.93, 95% CI = 1.13-3.28, p < .05) have independently positive associations with cessation of EBF during the first 6 months of infant life. The findings have helped to identify some important factors affecting EBF practices in the study area in Cambodia. The findings revealed that it is important to educate pregnant mothers, probably through exposure to trained midwives and media, so they may recognize the significance of EBF and will develop intention and plan to feed their babies, keeping in mind the benefits it may yield. Paternal involvement in breast-feeding classes may increase their awareness and consequently complement EBF practices. Finally, development of conducive working environments and policies for working mothers should be carefully explored because it could have positive influence in better care and promotion of EBF. Copyright © 2010 Elsevier Inc. All rights reserved.

Effect of early exclusive breastfeeding on morbidity among infants born to HIV-negative mothers in Zimbabwe.

PubMed

Koyanagi, Ai; Humphrey, Jean H; Moulton, Lawrence H; Ntozini, Robert; Mutasa, Kuda; Iliff, Peter; Black, Robert E

2009-05-01

Early exclusive breastfeeding (EBF) is recommended by the World Health Organization, but EBF rates remain low throughout the world. For infants born to breastfeeding HIV-positive mothers, early EBF is associated with a lower risk of postnatal transmission than is feeding breast milk together with other liquids or foods. No studies conducted in Africa have reported any benefits of EBF for infants born to HIV-negative women. The objective was to compare the rate of sick clinic visits by infants aged 43-182 d according to breastfeeding exclusivity [EBF, predominant breastfeeding (PBF), and mixed breastfeeding (MBF)]. We compared rates of all-cause clinic visits and clinic visits related to diarrhea and lower respiratory tract infection (LRTI) among a cohort of 9207 infants of HIV-negative mothers during 2 age intervals: 43-91 and 92-182 d according to exclusivity of breastfeeding. Breastfeeding exclusivity was defined in 2 ways ("ever since birth" and "previous 7 d") and was assessed at 43 and 91 d. EBF between birth and 3 mo was significantly protective against diarrhea between 3 and 6 mo of age with the "ever since birth" definition [incidence rate ratios (IRRs) of 8.83 (95% CI: 1.07, 65.53) and 8.76 (95% CI: 1.13, 68.09) for PBF and MBF, respectively] and with the "previous 7 d" definition [2.04 (95% CI: 1.11, 3.77) and 2.05 (95% CI: 1.13, 3.72) for PBF and MBF, respectively]. The adverse effect of MBF on LRTI visits was weaker, reaching borderline significance only by the "ever since birth" definition during the 43-91-d interval (IRR: 1.91; 95% CI: 0.99, 3.67). Early EBF is associated with a significant reduction in sick clinic visits, especially those due to diarrhea.

A single 24 h recall overestimates exclusive breastfeeding practices among infants aged less than six months in rural Ethiopia.

PubMed

Fenta, Esete Habtemariam; Yirgu, Robel; Shikur, Bilal; Gebreyesus, Seifu Hagos

2017-01-01

Exclusive breastfeeding (EBF) to six months is one of the World Health Organization's (WHOs) infant and young child feeding (IYCF) core indicators. Single 24 h recall method is currently in use to measure exclusive breastfeeding practice among children of age less than six months. This approach overestimates the prevalence of EBF, especially among small population groups. This justifies the need to look for alternative measurement techniques to have a valid estimate regardless of population characteristics. The study involved 422 infants of age less than six months, living in Gurage zone, Southern Ethiopia. The study was conducted from January to February 2016. Child feeding practices were measured for seven consecutive days using 24 h recall method. Recall since birth, was used to measure breastfeeding practices from birth to the day of data collection. Data on EBF obtained by using single 24 h recall were compared with seven days repeated 24 h recall method. McNemar's test was done to assess if a significant difference existed in rates of EBF between measurement methods. The mean age of infants in months was 3 (SD -1.43). Exclusive breastfeeding prevalence was highest (76.7%; 95% CI 72.6, 80.8) when EBF was estimated using single 24 h recall. The prevalence of EBF based on seven repeated 24 h recall was 53.2% (95% CI: 48.3, 58.0). The estimated prevalence of EBF since birth based on retrospective data (recall since birth) was 50.2% (95% CI 45.4, 55.1). Compared to the EBF estimates obtained from seven repeated 24 h recall, single 24 h recall overestimated EBF magnitude by 23 percentage points (95% CI 19.2, 27.8). As the number of days of 24 h recall increased, a significant decrease in overestimation of EBF was observed. A significant overestimation was observed when single 24 h recall was used to estimate prevalence of EBF compared to seven days of 24 h recall. By increasing the observation days we can significantly decrease the degree of overestimation. Recall since birth presented estimates of EBF that is close to seven repeated 24 h recall. This suggests that a week recall could be an alternative indicator to single 24 h recall.

Laboratory testing of extravascular body fluids in Croatia: a survey of the Working group for extravascular body fluids of the Croatian Society of Medical Biochemistry and Laboratory Medicine

PubMed Central

Kopcinovic, Lara Milevoj; Vogrinc, Zeljka; Kocijan, Irena; Culej, Jelena; Aralica, Merica; Jokic, Anja; Antoncic, Dragana; Bozovic, Marija

2016-01-01

Introduction We hypothesized that extravascular body fluid (EBF) analysis in Croatia is not harmonized and aimed to investigate preanalytical, analytical and postanalytical procedures used in EBF analysis in order to identify key aspects that should be addressed in future harmonization attempts. Materials and methods An anonymous online survey created to explore laboratory testing of EBF was sent to secondary, tertiary and private health care Medical Biochemistry Laboratories (MBLs) in Croatia. Statements were designed to address preanalytical, analytical and postanalytical procedures of cerebrospinal, pleural, peritoneal (ascites), pericardial, seminal, synovial, amniotic fluid and sweat. Participants were asked to declare the strength of agreement with proposed statements using a Likert scale. Mean scores for corresponding separate statements divided according to health care setting were calculated and compared. Results The survey response rate was 0.64 (58 / 90). None of the participating private MBLs declared to analyse EBF. We report a mean score of 3.45 obtained for all statements evaluated. Deviations from desirable procedures were demonstrated in all EBF testing phases. Minor differences in procedures used for EBF analysis comparing secondary and tertiary health care MBLs were found. The lowest scores were obtained for statements regarding quality control procedures in EBF analysis, participation in proficiency testing programmes and provision of interpretative comments on EBF’s test reports. Conclusions Although good laboratory EBF practice is present in Croatia, procedures for EBF analysis should be further harmonized to improve the quality of EBF testing and patient safety. PMID:27812307

Exploring the influence of psychosocial factors on exclusive breastfeeding in Bangladesh.

PubMed

Islam, Md Jahirul; Baird, Kathleen; Mazerolle, Paul; Broidy, Lisa

2017-02-01

Exclusive breastfeeding is a proven benefit for both mothers and infants and is, therefore, an important public health priority. Intimate partner violence (IPV) is regarded as one of the potential psychosocial risk factors that may negatively affect exclusive breastfeeding (EBF). This study aimed to explore the influence of psychosocial factors including IPV on EBF. Cross-sectional survey data was collected from October 2015 to January 2016 in Chandpur District of Bangladesh from 426 married women, aged 15-49 years, who had at least one child 6 months of age or younger. Multivariate logistic regression models were used in order to investigate whether women who experienced IPV after childbirth, as well as other risk factors such as postpartum depression (PPD) and childhood sexual abuse, were more likely to face difficulties with EBF compared with women who had not experienced these same risk factors. Whilst the initiation rate of breastfeeding was 99.3%, at the time of the woman's interview, the overall EBF rate had fallen to 43.7%. Based on the adjusted model, women who experienced physical IPV (AOR 0.17, 95% CI [0.07, 0.40]) and psychological IPV (AOR 0.51, 95% CI [0.26, 1.00]) after childbirth and women who reported childhood sexual abuse (AOR 0.32, 95% CI [0.13, 0.80]) and PPD (AOR 0.20, 95% CI [0.09, 0.44]) were significantly less likely to exclusively breastfeed their infants than those who had not reported these experiences. Moreover, women with an intended pregnancy and high social support exhibited a higher likelihood of EBF. Our results suggest that preventing or reducing the occurrence of physical IPV, PPD and childhood sexual abuse may improve the EBF duration. Support from family members can assist in this process.

Breast-feeding practices in Mexico: results from the Second National Nutrition Survey 1999.

PubMed

González-Cossío, Teresa; Moreno-Macías, Hortensia; Rivera, Juan A; Villalpando, Salvador; Shamah-Levy, Teresa; Monterrubio, Eric A; Hernández-Garduño, Adolfo

2003-01-01

To assess breast-feeding (BF) practices and determinants of exclusive BF (EBF) < 4 and < 6 months (mo) among women and infants < 23 mo in the NNS-1999. BF practices from the day and night before the interview were ascertained, and median duration estimated. Determinants of EBF < 4 and < 6 mo were analysed by logistic regression models for complex surveys. Prevalence of EBF < 4 mo was 25.7%, and of < 6 mo 20.3%. The overall rate of continued BF (second year) was 30.9%, median duration of BF 9 mo, and the national proportion of children ever breast-fed 92.3%. The probability (p) of EBF < 4 mo was determined by infant age and sex, by maternal socio-economic level (SEL) and ethnicity, and by the interaction between infant sex and SEL. The pEBF < 6 mo was determined by infant age and length, by maternal ethnicity, and employment. EBF rates and duration are low in Mexico and have improved only slightly in the last 20 y. Infant and maternal characteristics determine the pEBF. If improvements in infant health are a national priority, aggressive interventions to promote and protect BF are urgently needed in Mexico, as well as formal evaluation of current initiatives. The English version of this paper is available too at: http://www.insp.mx/salud/index.html.

Exposure to mass media and interpersonal counseling has additive effects on exclusive breastfeeding and its psychosocial determinants among Vietnamese mothers

PubMed Central

Kim, Sunny S.; Nguyen, Tuan T.; Hajeebhoy, Nemat; Tran, Lan M.; Alayon, Silvia; Ruel, Marie T.; Rawat, Rahul; Frongillo, Edward A.; Menon, Purnima

2016-01-01

Abstract The pathways through which behavior change interventions impact breastfeeding practices have not been well studied. This study aimed to examine: (1) the effects of exposure to mass media and interpersonal counseling on exclusive breastfeeding (EBF) and hypothesized psychosocial determinants (i.e. knowledge, intention, beliefs, social norms, and self‐efficacy); and (2) the pathways through which exposure to mass media and interpersonal counseling are associated with EBF. We used survey data from mothers with children < 2 year (n = 2045) from the 2013 process evaluation of Alive & Thrive's program in Viet Nam. Multiple linear regression analyses and structural equation modeling were used to estimate effects. Exposure to mass media only, interpersonal counseling only, both or neither was 51%, 5%, 19% and 25%, respectively. Exposure to both mass media and interpersonal counseling had additive effects on EBF as well as on related psychosocial factors, compared with no exposure. For example, EBF prevalence was 26.1 percentage points (pp) higher in the group that received interpersonal counseling only, 3.9 pp higher in the mass media group and 31.8 pp higher in the group that received both interventions. As hypothesized, more than 90% of the total effect of the two interventions on EBF was explained by the psychosocial factors measured. Our findings suggest that combining different behavior change interventions leads to greater changes in psychosocial factors, which in turn positively affects breastfeeding behaviors. PMID:27334544

Addressing social barriers and closing the gender knowledge gap: exposure to road shows is associated with more knowledge and more positive beliefs, attitudes and social norms regarding exclusive breastfeeding in rural Zimbabwe.

PubMed

Jenkins, Alison L; Tavengwa, Naume V; Chasekwa, Bernard; Chatora, Kumbirai; Taruberekera, Noah; Mushayi, Wellington; Madzima, Rufaro C; Mbuya, Mduduzi N N

2012-10-01

Exclusive breastfeeding (EBF) is rarely practiced despite its significant child survival benefits. A key constraint to increasing EBF rates in Zimbabwe and most of the developing world is that key decision makers (fathers/partners and other family members) are often poorly informed about EBF and do not attend antenatal clinics where health information is routinely provided. Informed by formative research, a district-wide campaign was conducted in rural Zimbabwe to encourage EBF and expressing and heat treating (EHT) breast milk as a means to maintain EBF. The campaign combined traditional strategies of education, counselling and outreach through health service delivery with a novel road show 'edutainment' intervention to reach men and other community members. A post campaign evaluation measured the association of road show exposure with 20 knowledge items and summative scores of social norms, beliefs and attitudes obtained through exploratory factor analysis. In adjusted models, road show exposure was associated with correct EBF knowledge (β=1.0, 0.001), EHT knowledge (β=1.3, P<0.001) and greater perceived benefits of condom use during pregnancy and breastfeeding (β=0.5, P<0.001), and more positive EBF social norms (β=0.6, P<0.001), EBF beliefs and attitudes (β=1.0, P<0.001) and attitudes towards condom use during breastfeeding (β=0.6, P<0.001). Road show exposure was more strongly associated with EBF knowledge among men (P-value for gender×exposure group interaction=0.03), suggesting that it also closed the knowledge gap between men and women. Longitudinal studies will determine whether road shows were associated with changes in EBF practices. © 2011 Blackwell Publishing Ltd.

Factors Affecting Exclusive Breastfeeding among Women in Muheza District Tanga Northeastern Tanzania: A Mixed Method Community Based Study.

PubMed

Maonga, Aubrey R; Mahande, Michael J; Damian, Damian J; Msuya, Sia E

2016-01-01

Estimates shows exclusive breastfeeding (EBF) has the potential to prevent 11.6% of all under-five deaths in developing countries. Prevalence of EBF is low globally (35%), and in sub Saharan Africa ranges between 22 and 33%. Like other developing countries the prevalence of EBF is 50% in Tanzania. There is limited information in Tanzania on factors influencing EBF apart from information specific for HIV positive women. This study aimed at examining factors that affect EBF practice among women in Muheza district, Tanga region, northeastern Tanzania. A community based cross-sectional study using both qualitative and quantitative methods was conducted from April to June 2014. To collect relevant information, a total of 316 women with infants aged 6-12 months were interviewed using a questionnaire and 12 key informants using in-depth interview guide. Qualitative data was analyzed using thematic analysis while bivariate and multivariate logistic regression analysis were used assess association between EBF and predictor variables. The prevalence of EBF was 24.1%. The perception that mothers' breast milk is insufficient for child's growth, child being thirsty and the need to introduce herbal medicine for cultural purposes were among the important factors for early mixed feeding. In multivariate analysis advanced maternal age (OR 2.6; 95% CI 1.18-5.59) and knowledge on EBF duration and advantages (OR 2.2; 95% CI 1.2-3.8) remained significantly associated with EBF practice. The prevalence of EBF in our study is low compared with the national prevalence. Strategies to target beliefs that breast milk is insufficient for growth need to be strengthened in the community. Furthermore opportunity to increase EBF training during ante and postnatal visits for women should be enhanced as more than 90% of women in the district use skilled attendants during pregnancy and delivery.

Rare Variant, Gene-Based Association Study of Hereditary Melanoma Using Whole-Exome Sequencing.

PubMed

Artomov, Mykyta; Stratigos, Alexander J; Kim, Ivana; Kumar, Raj; Lauss, Martin; Reddy, Bobby Y; Miao, Benchun; Daniela Robles-Espinoza, Carla; Sankar, Aravind; Njauw, Ching-Ni; Shannon, Kristen; Gragoudas, Evangelos S; Marie Lane, Anne; Iyer, Vivek; Newton-Bishop, Julia A; Timothy Bishop, D; Holland, Elizabeth A; Mann, Graham J; Singh, Tarjinder; Daly, Mark J; Tsao, Hensin

2017-12-01

Extraordinary progress has been made in our understanding of common variants in many diseases, including melanoma. Because the contribution of rare coding variants is not as well characterized, we performed an exome-wide, gene-based association study of familial cutaneous melanoma (CM) and ocular melanoma (OM). Using 11 990 jointly processed individual DNA samples, whole-exome sequencing was performed, followed by large-scale joint variant calling using GATK (Genome Analysis ToolKit). PLINK/SEQ was used for statistical analysis of genetic variation. Four models were used to estimate the association among different types of variants. In vitro functional validation was performed using three human melanoma cell lines in 2D and 3D proliferation assays. In vivo tumor growth was assessed using xenografts of human melanoma A375 melanoma cells in nude mice (eight mice per group). All statistical tests were two-sided. Strong signals were detected for CDKN2A (Pmin = 6.16 × 10-8) in the CM cohort (n = 273) and BAP1 (Pmin = 3.83 × 10-6) in the OM (n = 99) cohort. Eleven genes that exhibited borderline association (P < 10-4) were independently validated using The Cancer Genome Atlas melanoma cohort (379 CM, 47 OM) and a matched set of 3563 European controls with CDKN2A (P = .009), BAP1 (P = .03), and EBF3 (P = 4.75 × 10-4), a candidate risk locus, all showing evidence of replication. EBF3 was then evaluated using germline data from a set of 132 familial melanoma cases and 4769 controls of UK origin (joint P = 1.37 × 10-5). Somatically, loss of EBF3 expression correlated with progression, poorer outcome, and high MITF tumors. Functionally, induction of EBF3 in melanoma cells reduced cell growth in vitro, retarded tumor formation in vivo, and reduced MITF levels. The results of this large rare variant germline association study further define the mutational landscape of hereditary melanoma and implicate EBF3 as a possible CM predisposition gene.

Rare Variant, Gene-Based Association Study of Hereditary Melanoma Using Whole-Exome Sequencing

PubMed Central

Artomov, Mykyta; Stratigos, Alexander J; Kim, Ivana; Kumar, Raj; Lauss, Martin; Reddy, Bobby Y; Miao, Benchun; Daniela Robles-Espinoza, Carla; Sankar, Aravind; Njauw, Ching-Ni; Shannon, Kristen; Gragoudas, Evangelos S; Marie Lane, Anne; Iyer, Vivek; Newton-Bishop, Julia A; Timothy Bishop, D; Holland, Elizabeth A; Mann, Graham J; Singh, Tarjinder; Daly, Mark J; Tsao, Hensin

2017-01-01

Abstract Background Extraordinary progress has been made in our understanding of common variants in many diseases, including melanoma. Because the contribution of rare coding variants is not as well characterized, we performed an exome-wide, gene-based association study of familial cutaneous melanoma (CM) and ocular melanoma (OM). Methods Using 11 990 jointly processed individual DNA samples, whole-exome sequencing was performed, followed by large-scale joint variant calling using GATK (Genome Analysis ToolKit). PLINK/SEQ was used for statistical analysis of genetic variation. Four models were used to estimate the association among different types of variants. In vitro functional validation was performed using three human melanoma cell lines in 2D and 3D proliferation assays. In vivo tumor growth was assessed using xenografts of human melanoma A375 melanoma cells in nude mice (eight mice per group). All statistical tests were two-sided. Results Strong signals were detected for CDKN2A (Pmin = 6.16 × 10-8) in the CM cohort (n = 273) and BAP1 (Pmin = 3.83 × 10‐6) in the OM (n = 99) cohort. Eleven genes that exhibited borderline association (P < 10‐4) were independently validated using The Cancer Genome Atlas melanoma cohort (379 CM, 47 OM) and a matched set of 3563 European controls with CDKN2A (P = .009), BAP1 (P = .03), and EBF3 (P = 4.75 × 10‐4), a candidate risk locus, all showing evidence of replication. EBF3 was then evaluated using germline data from a set of 132 familial melanoma cases and 4769 controls of UK origin (joint P = 1.37 × 10‐5). Somatically, loss of EBF3 expression correlated with progression, poorer outcome, and high MITF tumors. Functionally, induction of EBF3 in melanoma cells reduced cell growth in vitro, retarded tumor formation in vivo, and reduced MITF levels. Conclusions The results of this large rare variant germline association study further define the mutational landscape of hereditary melanoma and implicate EBF3 as a possible CM predisposition gene. PMID:29522175

Population attributable risk of key modifiable risk factors associated with non-exclusive breastfeeding in Nigeria.

PubMed

Ogbo, Felix Akpojene; Page, Andrew; Idoko, John; Agho, Kingsley E

2018-02-13

Non-exclusive breastfeeding (non-EBF) is a risk factor for many of the 2300 under-five deaths occurring daily in Nigeria - a developing country with approximately 40 million children. This study aimed to quantify and compare the attributable burden of key modifiable risk factors associated with non-EBF in Nigeria to inform strategic policy responses and initiatives. Relative risk and exposure prevalence for selected modifiable risk factors were used to calculate population attributable fractions based on Nigeria Demographic and Health Surveys data for the period (1999-2013). Scenarios based on feasible impact of community-based interventions in reducing exposure prevalence were also considered to calculate comparative potential impact fractions. In Nigeria, an estimated 22.8% (95% Confidence Interval, CI: 9.2-37.0%) of non-EBF was attributable to primary and no maternal education; 24.7% (95% CI: 9.5-39.5%) to middle and poor household wealth, 9.7% (1.7-18.1%) to lower number (1-3) and no antenatal care visits; 18.8% (95% CI: 6.9-30.8%) to home delivery and 16.6% (95% CI: 3.0-31.3%) to delivery assisted by a non-health professional. In combination, more than half of all cases of non-EBF (64.5%; 95% CI: 50.0-76.4%) could be attributed to those modifiable risk factors. Scenarios based on feasible impacts of community-based approaches to improve health service access and human capacity suggest that an avoidable burden of non-EBF practice of approximately 11% (95% CI: -5.4; 24.7) is achievable. Key modifiable risk factors contribute significantly to non-EBF in Nigerian women. Community-based initiatives and appropriate socio-economic government policies that specifically consider those modifiable risk factors could substantially reduce non-EBF practice in Nigeria.

Milk- and solid-feeding practices and daycare attendance are associated with differences in bacterial diversity, predominant communities, and metabolic and immune function of the infant gut microbiome.

PubMed

Thompson, Amanda L; Monteagudo-Mera, Andrea; Cadenas, Maria B; Lampl, Michelle L; Azcarate-Peril, M A

2015-01-01

The development of the infant intestinal microbiome in response to dietary and other exposures may shape long-term metabolic and immune function. We examined differences in the community structure and function of the intestinal microbiome between four feeding groups, exclusively breastfed infants before introduction of solid foods (EBF), non-exclusively breastfed infants before introduction of solid foods (non-EBF), EBF infants after introduction of solid foods (EBF+S), and non-EBF infants after introduction of solid foods (non-EBF+S), and tested whether out-of-home daycare attendance was associated with differences in relative abundance of gut bacteria. Bacterial 16S rRNA amplicon sequencing was performed on 49 stool samples collected longitudinally from a cohort of 9 infants (5 male, 4 female). PICRUSt metabolic inference analysis was used to identify metabolic impacts of feeding practices on the infant gut microbiome. Sequencing data identified significant differences across groups defined by feeding and daycare attendance. Non-EBF and daycare-attending infants had higher diversity and species richness than EBF and non-daycare attending infants. The gut microbiome of EBF infants showed increased proportions of Bifidobacterium and lower abundance of Bacteroidetes and Clostridiales than non-EBF infants. PICRUSt analysis indicated that introduction of solid foods had a marginal impact on the microbiome of EBF infants (24 enzymes overrepresented in EBF+S infants). In contrast, over 200 bacterial gene categories were overrepresented in non-EBF+S compared to non-EBF infants including several bacterial methyl-accepting chemotaxis proteins (MCP) involved in signal transduction. The identified differences between EBF and non-EBF infants suggest that breast milk may provide the gut microbiome with a greater plasticity (despite having a lower phylogenetic diversity) that eases the transition into solid foods.

Social and Economic Barriers to Exclusive Breast Feeding In Rural Zimbabwe.

PubMed

Muchacha, Munyaradzi; Mtetwa, Edmos

2015-01-01

Exclusive breast feeding (EBF) uptake in Zimbabwe is very low. Given that EBF is a physiological process which transpires in a specific socio-economic milieu, this study investigates the socio-economic factors militating against its uptake. The study used a mixed research methodology. The concurrent nested model of mixed methods was utilized using one data collection phase, during which both quantitative and qualitative data were collected simultaneously. The research noted that factors such as low education, low income, gender inequalities, social influence, and traditional practices were hindering the uptake of exclusive breast feeding. The study envisages that it is pertinent for infant feeding programs to address socio-economic barriers to EBF in order to influence a positive uptake. The potential interventions include increasing men's involvement, raising awareness on EBF, and strengthening the Village Health Worker Program.

Exposure to mass media and interpersonal counseling has additive effects on exclusive breastfeeding and its psychosocial determinants among Vietnamese mothers.

PubMed

Nguyen, Phuong H; Kim, Sunny S; Nguyen, Tuan T; Hajeebhoy, Nemat; Tran, Lan M; Alayon, Silvia; Ruel, Marie T; Rawat, Rahul; Frongillo, Edward A; Menon, Purnima

2016-10-01

The pathways through which behavior change interventions impact breastfeeding practices have not been well studied. This study aimed to examine: (1) the effects of exposure to mass media and interpersonal counseling on exclusive breastfeeding (EBF) and hypothesized psychosocial determinants (i.e. knowledge, intention, beliefs, social norms, and self-efficacy); and (2) the pathways through which exposure to mass media and interpersonal counseling are associated with EBF. We used survey data from mothers with children < 2 year (n = 2045) from the 2013 process evaluation of Alive & Thrive's program in Viet Nam. Multiple linear regression analyses and structural equation modeling were used to estimate effects. Exposure to mass media only, interpersonal counseling only, both or neither was 51%, 5%, 19% and 25%, respectively. Exposure to both mass media and interpersonal counseling had additive effects on EBF as well as on related psychosocial factors, compared with no exposure. For example, EBF prevalence was 26.1 percentage points (pp) higher in the group that received interpersonal counseling only, 3.9 pp higher in the mass media group and 31.8 pp higher in the group that received both interventions. As hypothesized, more than 90% of the total effect of the two interventions on EBF was explained by the psychosocial factors measured. Our findings suggest that combining different behavior change interventions leads to greater changes in psychosocial factors, which in turn positively affects breastfeeding behaviors. © 2016 The Authors. Maternal & Child Nutrition published by John Wiley & Sons Ltd.

The determinants of exclusive breast feeding in urban slums: a community based study.

PubMed

Tiwari, Ranjana; Mahajan, P C; Lahariya, Chandrakant

2009-02-01

The actual rate of Exclusive Breast Feeding (EBF) (up to the age of 6 months) is dismally low in urban slums of India. The reasons and determinants of this are debatable. The study was planned to understand the determinants of EBF in the infants in urban slums. A community-based cross sectional study was done in urban slums of Gwalior, India. The data were collected by interviewing the caregivers of 279 infants aged between 6 and 11 months from November 2005 to July 2006. Only 11 (3.8%) mothers knew that EBF should be done till six months and 22 (7.8%) actually practiced EBF. A total of 178 (63.8%) and 212 (76.0%) newborns were given pre- and post-lacteal feeds with 26.2% discarding colostrum. Only 22 (7.8%) practiced EBF. The early breastfeeding (BF) initiation, Ante Natal Clinic (ANC) visits, mothers' education and immunization visits were significantly associated with higher probability of EBF. There were a number of myths and misconceptions about BF in this urban slum population. The correct information about BF was more common amongst the women who had frequent contacts with health facilities due to any reason or during ANC or immunization visit. Similarly, it is the continuum of good health and feeding practices and the mothers who start early BF or get their child immunized regularly are more likely to EBF their children. Considering the widely prevalent myths and low rate of utilization of health services along with high potential benefits of EBF, every opportunity of mothers' interaction with the health facility should be utilized for promoting correct and EBF practices.

Gamma rays shielding and sensing application of some rare earth doped lead-alumino-phosphate glasses

NASA Astrophysics Data System (ADS)

Kaur, Preet; Singh, Devinder; Singh, Tejbir

2018-03-01

Seven rare earth (Sm3+, Eu3+ and Nd3+) doped lead alumino phosphate glasses were prepared. The protective and sensing measures from gamma rays were analysed in terms of parameters viz. density (ρ), refractive index, energy band gap (Eg), mean free path (mfp), effective atomic number (Zeff) and buildup factors (energy absorption EABF as well as exposure buildup factor EBF). The energy dependent parameters (mfp, Zeff, EABF and EBF) were investigated in the energy region from 15 keV to 15 MeV. EABF and EBF values were observed to be maximum in the intermediate energy region. Besides, the EABF and EBF values for the prepared samples are shown to have strong dependence on chemical composition of the glass at lower energy, whereas, it is almost independent of chemical composition in higher energy region. The prepared glass samples are found to have potential applications in radiation shielding as well as radiation sensing, which further find numerous applications in the field of medicine and industry.

Combined effects of maternal age and parity on successful initiation of exclusive breastfeeding

PubMed Central

Kitano, Naomi; Nomura, Kyoko; Kido, Michiko; Murakami, Keiko; Ohkubo, Takayoshi; Ueno, Masami; Sugimoto, Mitsuhiro

2015-01-01

Maternal age at first childbirth has increased in most developed countries in the past 20 years. The purpose of this study is to investigate effects of maternal age at delivery and parity on successful initiation of exclusive breastfeeding (EBF). This retrospective study investigated 1193 singleton dyads with vaginal-delivered at 37–42 gestational weeks during January and December in 2011 at one large “Baby-Friendly” certified hospital in Japan. A multivariate logistic regression model was used to evaluate individual and combined effects of maternal age and parity on successful initiation of EBF after adjusted for pre-pregnancy body mass index, gestational weight gain, pregnancy complications, mothers' underlying illness, smoking and alcohol drinking habits, gestational week at delivery, child's sex and nurturing support from grandparents. Success rates of EBF at one month after child delivery was 69.4% in primiparous aged ≥ 35 (group A: n = 284), 73.5% in multiparous aged ≥ 35 (group B: n = 268), 74.3% in primiparous aged < 35 (group C: n = 432), and 82.3% in multiparous aged < 35 (group D: n = 209). Older maternal age and primiparous became independently associated with EBF initiation. The combined effect for successful initiation of EBF was the lowest in group A referent to group D both at discharge and at one month (odds ratio (OR) 5.9, 95% confidence interval (CI): 3.0–11.9, and OR 2.2, 95% CI: 1.4–3.4, respectively). Primiparous mothers in late child-bearing aged 35 years or older are at the greatest risk of EBF initiation. PMID:26844198

Breastfeeding at 6 weeks and predictive factors.

PubMed

Chye, J K; Zain, Z; Lim, W L; Lim, C T

1997-10-01

Despite the numerous changes made in accordance with the Baby Friendly Hospital Initiative at the University Hospital, Kuala Lumpur, the low rates of breastfeeding have persisted. This study aims to examine the current trend in infant feeding, and the influences of some perinatal and sociodemographic factors on breastfeeding. Five-hundred mothers with singleton pregnancies and healthy infants were interviewed at 6 weeks post-partum. Only 124 (25 per cent) mothers were practising exclusive breastfeeding (EBF), and 132 (26 per cent) mothers were using exclusive infant formula feeding (EIF). On logistic regression analyses, mothers who followed EBF were more likely to have had antenatal plans to breastfeed (Odds ratio 2.44, 95 per cent confidence interval 1.75-3.45), not in paid employment post-natally (OR 1.76, 95 per cent CI 1.31-2.36), of older age group (> 27 years) (OR 1.48, 95 per cent CI 1.13-1.93), had female infants (OR 1.38, 95 per cent CI 1.05-1.80) and of Indian ethnicity (compared to Chinese) (OR 3.87, 95 per cent CI 2.16-6.89). Breastfeeding difficulties were associated with decreased odds of EBF (OR 0.21, 95 per cent CI 0.13-0.34). Parental education, fathers' ages and incomes, primigravida status, Caesarean section, present of episiotomy, late first breastfeed, phototherapy, and length of hospital stay were not significant predictors of failure of EBF. In comparison, predictive factors for increased use of EIF were mothers who have had breastfeeding difficulties, < or = 9 years of schooling, and of Chinese descent. In conclusions, the overall rate of EBF by 6 weeks of age in infants born in this urban hospital had remained poor. The adverse factors for EBF identified in this study warrant further in-depth studies to determine effective ways of improving EBF rates.

Improved rates of exclusive breastfeeding at 14 weeks of age in KwaZulu Natal, South Africa: what are the challenges now?

PubMed

Horwood, C; Haskins, L; Engebretsen, I M; Phakathi, S; Connolly, C; Coutsoudis, A; Spies, L

2018-06-19

Increasing the rate of exclusive breastfeeding (EBF) to 50% in the first six months of life is one of six major global targets set by the United Nations Decade of Nutrition, and is essential to achieve the sustainable development goals to eradicate hunger and end malnutrition by 2030. A survey using multistage random sampling design included 99 primary health care (PHC) clinics in all 11 districts in KwaZulu-Natal (KZN). All mothers and caregivers of infants 14 weeks of age attending the clinics in the study period were requested to participate in a structured interview to explore feeding practices since birth. As non-maternal caregivers may not have detailed knowledge of feeding practices, they provided limited information about current feeding practices. Respondents who consistently reported giving no other food or fluids except breastmilk since birth were classified as practising exclusive breastfeeding (EBF), and those who were currently breastfeeding but had given other food or fluids since birth were categorised as practising mixed breastfeeding (MBF). A total of 4172 interviews were conducted with mothers and caregivers of 14 week old infants. Among mothers 49.8% were EBF, 23.1% were MBF and 27.0% were not breastfeeding. Among non-maternal caregivers 11.8% reported EBF, 23.4% MBF and 62.3% were not giving breastmilk. Higher education (OR 0.6, 95% CI 0.4-0.8) and being in the highest socio-economic tertile (OR 0.7, 95% CI 0.6-0.9) were risk factors for not practising EBF, while returning to work (OR 0.3, 95% CI 0.2-0.3) or school (OR 0.2 95% CI, 0.1-0.3) was associated with less EBF. HIV-positive mothers were more likely to have never started breastfeeding (OR 3.6, 95% CI 2.7-4.8). However, they were similar in having stopped breastfeeding by 14 weeks (OR 1.1, 95% CI 0.9-1.4) compared to HIV-negative mothers, and, they had similar rates of EBF at 14 weeks of age (OR 1.0, 95% CI 0.9-1.3). Estimates of breastfeeding practices at 14 weeks in KZN are higher than previously shown. However, particular challenges that should be addressed if international targets for EBF are to be achieved include improving breastfeeding practices of HIV positive mothers and supporting all mothers, particularly working or schooling mothers to continue giving breastmilk while they are away from their children.

Comprehensive study on estimation of gamma-ray exposure buildup factors for smart polymers as a potent application in nuclear industries

NASA Astrophysics Data System (ADS)

Sayyed, M. I.; AlZaatreh, M. Y.; Matori, K. A.; Sidek, H. A. A.; Zaid, M. H. M.

2018-06-01

In the present study, the exposure buildup factors (EBF) have been investigated using geometric progression (G-P) fitting method for different types of smart polymers (DMSO, PDMS, PES, PMA, PVDC, and PVDF) in the energy range of 0.015-15 MeV. From the calculations, the values of the EBF were depended on the incident photon energy, penetration depth as well as chemical composition of the polymers. In the intermediate energy region, the EBF values were reached at maximum point while in low and high energy regions, the EBF values were decreased at minimum point. The obtained results of the selected polymers have been compared in terms of EBF with Al2O3 and other common polymers such as PAN, Teflon and SR. The shielding effectiveness of the selected polymers is found to be comparable to the common polymers. The results of this work should be useful in radiation shielding applications such as in industry, medical and nuclear engineering.

EBF factors drive expression of multiple classes of target genes governing neuronal development.

PubMed

Green, Yangsook S; Vetter, Monica L

2011-04-30

Early B cell factor (EBF) family members are transcription factors known to have important roles in several aspects of vertebrate neurogenesis, including commitment, migration and differentiation. Knowledge of how EBF family members contribute to neurogenesis is limited by a lack of detailed understanding of genes that are transcriptionally regulated by these factors. We performed a microarray screen in Xenopus animal caps to search for targets of EBF transcriptional activity, and identified candidate targets with multiple roles, including transcription factors of several classes. We determined that, among the most upregulated candidate genes with expected neuronal functions, most require EBF activity for some or all of their expression, and most have overlapping expression with ebf genes. We also found that the candidate target genes that had the most strongly overlapping expression patterns with ebf genes were predicted to be direct transcriptional targets of EBF transcriptional activity. The identification of candidate targets that are transcription factor genes, including nscl-1, emx1 and aml1, improves our understanding of how EBF proteins participate in the hierarchy of transcription control during neuronal development, and suggests novel mechanisms by which EBF activity promotes migration and differentiation. Other candidate targets, including pcdh8 and kcnk5, expand our knowledge of the types of terminal differentiated neuronal functions that EBF proteins regulate.

Exclusive breastfeeding among women taking HAART for PMTCT of HIV-1 in the Kisumu Breastfeeding Study.

PubMed

Okanda, John O; Borkowf, Craig B; Girde, Sonali; Thomas, Timothy K; Lecher, Shirley Lee

2014-11-07

One of the most effective ways to promote the prevention of mother-to-child transmission (PMTCT) of HIV-1 in resource-limited settings is to encourage HIV-positive mothers to practice exclusive breastfeeding (EBF) for the first 6 months post-partum while they receive antiretroviral therapy (ARV). Although EBF reduces mortality in this context, its practice has been low. We studied the rate of adherence to EBF and assessed associated maternal and infant characteristics using data from a phase II PMTCT clinical trial conducted in Western Kenya which included a counseling intervention to encourage EBF by all participants. We analyzed data from the Kisumu Breastfeeding Study (KiBS), conducted between July 2003 and February 2009. This study enrolled a total of 522 HIV-1 infected pregnant women. Data on breastfeeding were available for 480 mother-infant pairs. Infant feeding and general nutrition counseling began at 35 weeks gestation and continued throughout the 6 month post-partum intervention period, following World Health Organization (WHO) infant feeding guidelines. Data on infant feeding were collected during routine clinic visits and home visits using food frequency questionnaires and dietary recall methods. Participants were instructed to exclusively breastfeed until initiation of weaning at 5.5 months post-partum. We used Kaplan-Meier methods to estimate the rates of EBF at 5.25 months post-partum, stratified by maternal and infant characteristics measured at enrollment, delivery, and 2 weeks post-partum. The estimated EBF rate at 5.25 months post-partum was 80.4%. Only 3% of women introduced other foods (most commonly water with or without glucose, cow's milk, formula, and fruit) by 2 months; this percentage increased to 5% of women by 4 months. Women who had ≥3 previous births (p < 0.01) and who were not living with the infant's father (p = 0.04) were more likely to exclusively breastfeed. Mixed feeding was more common for male infants than for female infants (p = 0.04). Exclusive breastfeeding was common in this clinical trial, which emphasized EBF as a best practice until infants reached 5.5 months of age. Counseling initiated prior to delivery and continued during the post-partum period provided a consistent message reinforcing the benefits of EBF. The findings from this study suggest high adherence to EBF in resource limited settings can be achieved by a comprehensive counseling intervention that encourages EBF.

[Effect of the Baby Friendly Hospital Initiative on the duration of exclusive breastfeeding in Kinshasa: A cluster randomized trial].

PubMed

Babakazo, P; Donnen, P; Mapatano, M A; Lulebo, A; Okitolonda, E

2015-10-01

Despite numerous advantages of breastfeeding, in Democratic Republic of the Congo, the rate of children exclusively breastfed up to six months remains low. The lack of breastfeeding support received by mothers from health care providers is an important factor of early cessation of breastfeeding. This study aimed to evaluate the effect of the training of health care providers, in the Baby Friendly Hospital Initiative, on the duration of exclusive breastfeeding (EBF) in Kinshasa. A total of 422 mothers, recruited during the first antenatal care visit in 12 maternities and followed up to six months after delivery, were included in a cluster randomized trial. In the experimental group, health care providers were trained using the "20-Hour Course For Maternity Staff". Cox proportional hazards model was used to determine the effect of the intervention on the duration of EBF. The rate of EBF at six months was 2.8%; the median duration of EBF was 10.9 weeks (IQR 4.3 to 14.9). The hazard of discontinuing EBF before six month was 1.4 times higher in the control group (adjusted HR [95%CI]=1.40 (1.10-1.78), P=0.007). In this study, training of health care providers in the Baby Friendly Hospital Initiative was associated with a significant improvement in the duration of EBF. Extending this training to different maternities could improve the coverage of EBF in Kinshasa. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Potential effectiveness of Community Health Strategy to promote exclusive breastfeeding in urban poor settings in Nairobi, Kenya: a quasi-experimental study.

PubMed

Kimani-Murage, E W; Norris, S A; Mutua, M K; Wekesah, F; Wanjohi, M; Muhia, N; Muriuki, P; Egondi, T; Kyobutungi, C; Ezeh, A C; Musoke, R N; McGarvey, S T; Madise, N J; Griffiths, P L

2016-04-01

Early nutrition is critical for later health and sustainable development. We determined potential effectiveness of the Kenyan Community Health Strategy in promoting exclusive breastfeeding (EBF) in urban poor settings in Nairobi, Kenya. We used a quasi-experimental study design, based on three studies [Pre-intervention (2007-2011; n=5824), Intervention (2012-2015; n=1110) and Comparison (2012-2014; n=487)], which followed mother-child pairs longitudinally to establish EBF rates from 0 to 6 months. The Maternal, Infant and Young Child Nutrition (MIYCN) study was a cluster randomized trial; the control arm (MIYCN-Control) received standard care involving community health workers (CHWs) visits for counselling on antenatal and postnatal care. The intervention arm (MIYCN-Intervention) received standard care and regular MIYCN counselling by trained CHWs. Both groups received MIYCN information materials. We tested differences in EBF rates from 0 to 6 months among four study groups (Pre-intervention, MIYCN-Intervention, MIYCN-Control and Comparison) using a χ(2) test and logistic regression. At 6 months, the prevalence of EBF was 2% in the Pre-intervention group compared with 55% in the MIYCN-Intervention group, 55% in the MIYCN-Control group and 3% in the Comparison group (P<0.05). After adjusting for baseline characteristics, the odds ratio for EBF from birth to 6 months was 66.9 (95% CI 45.4-96.4), 84.3 (95% CI 40.7-174.6) and 3.9 (95% CI 1.8-8.4) for the MIYCN-Intervention, MIYCN-Control and Comparison group, respectively, compared with the Pre-intervention group. There is potential effectiveness of the Kenya national Community Health Strategy in promoting EBF in urban poor settings where health care access is limited.

Factors affecting exclusive breast-feeding during the first 6 months in Korea.

PubMed

Kim, Myo Jing; Kim, Yu-Mi; Yoo, Jae-Ho

2013-04-01

The aim of this study was to identify the status of exclusive breast-feeding (EBF) in Korea and analyze the factors affecting exclusive breast-feeding at 6 months of age. This study was based on data obtained from the Korea National Health and Nutrition Examination Survey (KNHANES) IV, conducted from January 2007 to December 2008. A total of 404 mother-infant pairs were recruited. Exclusive breast-feeding was defined according to the criteria established by the World Health Organization. The rate of EBF was 60.9% for 1 month, 55.0% for 3 months, 35.4% for 6 months, 3.7% for 9 months and 1.2% for 12 months after birth. According to a stepwise logistic regression analysis, factors that were positively associated with EBF at 6 months were younger maternal age (odds ratio [OR] = 0.85, 95% confidence interval [CI]: 0.79-0.92), higher maternal education level (OR = 2.29, 95%CI: 1.17-4.46) and living in a capital city (OR = 2.64, 95%CI: 1.46-4.75). The rate of EBF in Korea is still suboptimal. To promote EBF, persistent and systematic education and campaigns for breast-feeding should be provided, particularly in vulnerable regions. © 2012 The Authors. Pediatrics International © 2012 Japan Pediatric Society.

Benefits of a Dedicated Breastfeeding Facility and Support Program for Exclusive Breastfeeding among Workers in Indonesia.

PubMed

Basrowi, Ray W; Sulistomo, Astrid B; Adi, Nuri Purwito; Vandenplas, Yvan

2015-06-01

A mother's working environment is believed to be a major determinant of exclusive breastfeeding (EBF) practice. We aimed to define the influence of a facility dedicated to breastfeeding and a breastfeeding support program at the workplace on breastfeeding practice. A cross-sectional study was performed in five workplaces. The inclusion criteria were female workers whose last child was between 6 and 36 months old. Observational data were obtained and a questionnaire was filled out. The World Health Organization definition for EBF was used. Data from 186 subjects (74 office workers and 112 factory workers) were collected. Just over half (52%) of the mothers were between 20 and 46 years old, 75.3% had graduated from high school and university, 12.9% had more than two children and 36.0% owned a house. The prevalence of EBF during the last 6 months was 32.3%. A proper dedicated breastfeeding facility was available for 21.5% of the mothers, but only 7.5% had been in contact with a breastfeeding support program. The presence of a dedicated breastfeeding facility increased EBF practice almost threefold, by an odds ratio (OR) of 2.74 and a 95% confidence interval (CI) of 1.34-5.64 (p<0.05). Knowledge of the breastfeeding support program increased EBF practice by almost six times (OR, 5.93; 95% CI, 1.78-19.79) (p<0.05). Our findings suggest that Governments should make it obligatory for employers to offer a breastfeeding support program and a dedicated breastfeeding facility at the workplace as these simple measures significantly increase EBF.

Exclusive Breastfeeding and Clinical Malaria Risk in 6-Month-Old Infants: A Cross-Sectional Study from Kinshasa, Democratic Republic of the Congo

PubMed Central

Brazeau, Nicholas F.; Tabala, Martine; Kiketa, Landry; Kayembe, Dyna; Chalachala, Jean Lambert; Kawende, Bienvenu; Lapika, Bruno; Meshnick, Steven R.; Yotebieng, Marcel

2016-01-01

The World Health Organization recommends exclusive breastfeeding (EBF) for the first 6 months of life. However, the effect of EBF on malaria risk remains unclear. In the present study, 137 EBF infants and 358 non-EBF infants from the Democratic Republic of the Congo were assessed for fever and malaria infections by polymerase chain reaction, at 6 months of age. EBF was associated with a reduced risk of clinical malaria (odds ratio = 0.13; 95% confidence interval = 0.00–0.80), suggesting a protective effect of EBF against malaria. PMID:27549632

Benefits of a Dedicated Breastfeeding Facility and Support Program for Exclusive Breastfeeding among Workers in Indonesia

PubMed Central

Basrowi, Ray W; Sulistomo, Astrid B; Adi, Nuri Purwito

2015-01-01

Purpose A mother's working environment is believed to be a major determinant of exclusive breastfeeding (EBF) practice. We aimed to define the influence of a facility dedicated to breastfeeding and a breastfeeding support program at the workplace on breastfeeding practice. Methods A cross-sectional study was performed in five workplaces. The inclusion criteria were female workers whose last child was between 6 and 36 months old. Observational data were obtained and a questionnaire was filled out. The World Health Organization definition for EBF was used. Results Data from 186 subjects (74 office workers and 112 factory workers) were collected. Just over half (52%) of the mothers were between 20 and 46 years old, 75.3% had graduated from high school and university, 12.9% had more than two children and 36.0% owned a house. The prevalence of EBF during the last 6 months was 32.3%. A proper dedicated breastfeeding facility was available for 21.5% of the mothers, but only 7.5% had been in contact with a breastfeeding support program. The presence of a dedicated breastfeeding facility increased EBF practice almost threefold, by an odds ratio (OR) of 2.74 and a 95% confidence interval (CI) of 1.34-5.64 (p<0.05). Knowledge of the breastfeeding support program increased EBF practice by almost six times (OR, 5.93; 95% CI, 1.78-19.79) (p<0.05). Conclusion Our findings suggest that Governments should make it obligatory for employers to offer a breastfeeding support program and a dedicated breastfeeding facility at the workplace as these simple measures significantly increase EBF. PMID:26157694

Exclusive Breastfeeding and Clinical Malaria Risk in 6-Month-Old Infants: A Cross-Sectional Study from Kinshasa, Democratic Republic of the Congo.

PubMed

Brazeau, Nicholas F; Tabala, Martine; Kiketa, Landry; Kayembe, Dyna; Chalachala, Jean Lambert; Kawende, Bienvenu; Lapika, Bruno; Meshnick, Steven R; Yotebieng, Marcel

2016-10-05

The World Health Organization recommends exclusive breastfeeding (EBF) for the first 6 months of life. However, the effect of EBF on malaria risk remains unclear. In the present study, 137 EBF infants and 358 non-EBF infants from the Democratic Republic of the Congo were assessed for fever and malaria infections by polymerase chain reaction, at 6 months of age. EBF was associated with a reduced risk of clinical malaria (odds ratio = 0.13; 95% confidence interval = 0.00-0.80), suggesting a protective effect of EBF against malaria. © The American Society of Tropical Medicine and Hygiene.

Hydration status of exclusively and partially breastfed near-term newborns in the first week of life.

PubMed

Kusuma, Sirisha; Agrawal, Sunil Kumar; Kumar, Praveen; Narang, Anil; Prasad, Rajendra

2009-08-01

An in-hospital prospective, observational cohort study was conducted to assess the effects of type of feeding (exclusively breastfed [EBF] vs partially breastfed [PBF]) on the hydration status of near-term newborns in the first week of life. A total of 205 babies of 35 to 37 weeks of completed gestation were enrolled (82 in the EBF group and 123 in the PBF group). The overall incidence of significant weight loss (>or=10%) was 18% with no significant difference between EBF and PBF groups (18.3% vs 17.9%, P=.94). The incidence of hypernatremia (serum NA>or=150 meq/L) was 2.4% in the EBF group and 5.7% in the PBF group (P=.32). The factors associated with significant weight loss in the total cohort were having a mother with previous negative breastfeeding experience (adjusted odds ratio [OR]=16.5, 95% confidence interval [CI]=2.1-115.7), exposure to phototherapy (adjusted OR=9.0, 95% CI=2.5-31.8), and cesarean delivery (adjusted OR=6.7, 95% CI=2.3-19.7).

Effect of low cost public health staff training on exclusive breastfeeding.

PubMed

Agampodi, Suneth Buddhika; Agampodi, Thilini Chanchala

2008-11-01

To assess the effectiveness and feasibility of on the job staff training and supportive supervision to improve six months Exclusive Breastfeeding (EBF). A longitudinal study was conducted in a public health field practice area-Sri Lanka in 2006-2007. Three breastfeeding counseling sessions were conducted for public health midwives. Supportive supervision and on the job training were done by two public health physicians. Pre and post intervention independent cross sectional studies were conducted to assess the effectiveness of the programme. The study sample consisted of mother-infant pairs where infants were aging 6 to 12 months, attending child welfare clinics. Primary outcome measure was the proportion of infants who received EBF up to 6 months. Logistic regressing model was used for analysis of predictors of EBF. Study sample consisted of 336 mother-infant pairs (pre 139, post 197). Proportion of mothers who breastfed their infants exclusively for six months improved from 19% to 70% after the intervention. The median duration of EBF increased from 4 months to 6 months (inter-quartile range 2-6 and 5-6 months respectively). Unconfounded effect of intervention on 6 months EBF in logistic regression model was highly significant (OR=13.67. p<0.001). Intervention significantly reduced the bottle feeding rate (OR=0.212, p<0.001) but not formula feeding (OR=1.146. p=0.642). Of potential predictors assessed. Sinhalese mothers than Muslim mothers (OR=3.37, p<0.001) and employed mothers compared to housewives (OR=4.45. p=0.014) were more likely to breastfeed their infants upto six months. Parity, maternal education and maternal age were not significantly associated with six months EBF. The existing public health infrastructure can be used effectively to improve six months EBF in places where the care is given primarily by public health system.

The Influence of Seasonality and Community-Based Health Worker Provided Counselling on Exclusive Breastfeeding - Findings from a Cross-Sectional Survey in India

PubMed Central

Das, Aritra; Chatterjee, Rahul; Karthick, Morchan; Mahapatra, Tanmay; Chaudhuri, Indrajit

2016-01-01

Background Exclusive breastfeeding (EBF) during the first six months of life is considered a high impact but low-cost measure for reducing the morbidity and mortality among children. The current study investigated the association of seasonality and frontline worker(FLW) provided counselling with practice of EBF in Bihar, India. Methods We used the ‘Lot Quality Assurance Sampling’ technique to conduct a multi-stage sampling survey in 8 districts of Bihar. Regarding EBF, mothers of 0–5 (completed) months old children were asked if they had given only breastmilk to their children during the previous day, while mothers of 6–8 (completed) months old children were inquired about the total duration of EBF. We tested for association between EBF during the previous day with season of interview and EBF for full 6 months with nursing season. We also assessed if receiving counselling on EBF and complementary feeding had any association with relevant EBF indicators. Results Among the under-6 month old children, 76% received EBF during the previous day, whereas 92% of 6–8 (completed) months old children reportedly received EBF for the recommended duration. Proportion of 0–5 (completed) month old children receiving only breastmilk (during last 24 hours) decreased significantly with increasing age and with change of season from colder to warmer months. Odds of receiving only breastmilk during the previous day was significantly higher during the winter months (Adjusted odds ratio(AOR) = 1.50; 95% CI = 1.37, 1.63) compared to summer. Also, the children nursed primarily during the winter season had higher odds of receiving EBF for 6 months (AOR = 1.90, 95% CI = 1.43, 2.52) than those with non-winter nursing. Receiving FLW-counselling was positively associated with breastfeeding exclusively, even after adjusting for seasonality and other covariates (AOR = 1.82; 95% CI = 1.67, 1.98). Conclusions Seasonality is a significant but non-modifiable risk factor for EBF. However, FLW-counselling was found to increase practice of EBF irrespective of season. Scale-up of FLW-counselling services, with emphasis on summer months and mothers of older infants, can potentially reduce the impact of seasonality on EBF. PMID:27513642

Ebf2 is required for development of dopamine neurons in the midbrain periaqueductal gray matter of mouse.

PubMed

Yang, Qiaoqiao; Liu, Shuxi; Yin, Min; Yin, Yanqing; Zhou, Guomin; Zhou, Jiawei

2015-11-01

Dopaminergic (DA) neurons in the midbrain ventral periaqueductal gray matter (PAG) play critical roles in various physiological and pathophysiological processes including sleep-wake rhyme, antinociception, and drug addiction. However, the molecular mechanisms underlying their development are poorly understood. Here, we showed that PAG DA neurons arose as early as E15.5 in mouse embryos. During the prenatal period, the majority of PAG DA neurons was distributed in the intermediate and caudal regions of the PAG. In the postnatal brain, ∼50% of PAG DA neurons were preferentially located in the caudal portion of the PAG. Moreover, transcription factor early B-cell factor 2 (Ebf2) was transiently expressed in a subset of DA neurons in embryonic ventral mesencephalon. Functional analysis revealed that loss of Ebf2 in vivo caused a marked reduction in the number of DA neurons in the midbrain PAG but not in the substantia nigra and ventral tegmental area. Thus, Ebf2 is identified as a novel and important regulator selectively required for midbrain PAG DA neuron development. © 2015 Wiley Periodicals, Inc.

Prevalence of breast-feeding and exclusive breast-feeding at 48 h after birth and up to the sixth month in Cyprus: the BrEaST start in life project.

PubMed

Economou, Mary; Kolokotroni, Ourania; Paphiti-Demetriou, Irene; Kouta, Christiana; Lambrinou, Ekaterini; Hadjigeorgiou, Eleni; Hadjiona, Vasiliki; Tryfonos, Froso; Philippou, Elena; Middleton, Nicos

2018-04-01

To assess the prevalence and sociodemographic determinants of breast-feeding (BF) and exclusive breast-feeding (EBF) in Cyprus up to the sixth month. Cross-sectional and longitudinal descriptive study. BF and EBF were estimated based on mothers' self-reported BF status in line with Step 7 of the WHO/UNICEF Baby-Friendly Hospital Initiative questionnaire and based on 24 h recall. Maternity wards in all public hospitals and twenty-nine (of thirty-five) private maternity clinics nationwide. Consecutive sample of 586 mothers recruited within 48 h from birth, followed up by telephone interview at the first, fourth and sixth month. Although 84·3 % of mothers initiated BF before discharge, prevalence of BF at the sixth month was 32·4 %, with the highest reduction observed between the first and fourth months. Prevalence of EBF at 48 h was 18·8 % and fell gradually to 5·0 % at the sixth month. Mothers with higher educational attainment or higher family income were more likely to breast-feed until the sixth month. In terms of EBF, an association was observed only with education, which persisted until the sixth month. Other than social gradient, mode of delivery was the strongest determinant of BF initiation, exclusivity and continuation. Mothers who gave birth vaginally were three to four times more likely to initiate BF (OR=3·1; 95 % CI 1·7, 5·4) and EBF (OR=4·3; 95 % CI 2·7, 6·8). The low prevalence of BF and EBF in Cyprus, together with the fact that caesarean section rates are currently among the highest in Europe, suggest the need for further research to understand this multidimensional phenomenon and for interdisciplinary policy action to protect, promote and support BF.

Utilizing a Newly Designed Scale for Evaluating Family Support and Its Association with Exclusive Breastfeeding.

PubMed

Zhu, Xiu; Liu, Luyan; Wang, Yan

2016-12-01

Although a woman's perception of her family members' support has long been established to be an influential factor on exclusive breastfeeding (EBF), it still has not been specified and quantified as a facilitator and guidance for practice. To investigate in new mothers the association between EBF and maternal perception of family support with a standardized scale that classified support into nine items of behavioral or psychological support. A cross-sectional survey was carried out among 655 new mothers to collect information on their breastfeeding behavior and their corresponding family support at a baby-friendly hospital in Beijing, China. Additionally, a nine-item standardized scale was used to explore the perceived family support for breastfeeding by new mothers. Breastfeeding behaviors were investigated using the indicators recommended by the Multiple Indicator Cluster Surveys. The EBF rate was 37.9%. The average score on the family perception scale reported by respondents was 28.34 ± 3.84. The new mothers who performed EBF and who predominantly breastfed perceived greater family support (29.55 ± 3.53; 29.36 ± 4.09) compared with those who performed complementary feeding or mixed feeding (26.69 ± 3.33) and those who performed artificial feeding (26.17 ± 3.14) (F = 30.296, p < 0.001). A binary logistic regression model was applied, and a stepwise regression analysis was performed with these factors; it showed that mothers with a positive perception of family support were more likely to practice EBF than those with a negative perception (adjusted odds ratio = 3.971; 95% confidence interval 2.62-6.01; p < 0.001). The EBF rate was quite low in the population investigated. Family support for breastfeeding could be evaluated by a scale, and new mothers' breastfeeding behaviors were strongly associated with their perceived family support for breastfeeding. Community healthcare providers should play a more important role in issues regarding breastfeeding among new mothers, and family support should be encouraged by health workers.

The caudo-ventral pallium is a novel pallial domain expressing Gdf10 and generating Ebf3-positive neurons of the medial amygdala.

PubMed

Ruiz-Reig, Nuria; Andres, Belen; Lamonerie, Thomas; Theil, Thomas; Fairén, Alfonso; Studer, Michèle

2018-06-04

In rodents, the medial nucleus of the amygdala receives direct inputs from the accessory olfactory bulbs and is mainly implicated in pheromone-mediated reproductive and defensive behaviors. The principal neurons of the medial amygdala are GABAergic neurons generated principally in the caudo-ventral medial ganglionic eminence and preoptic area. Beside GABAergic neurons, the medial amygdala also contains glutamatergic Otp-expressing neurons cells generated in the lateral hypothalamic neuroepithelium and a non-well characterized Pax6-positive population. In the present work, we describe a novel glutamatergic Ebf3-expressing neuronal subpopulation distributed within the periphery of the postero-ventral medial amygdala. These neurons are generated in a pallial domain characterized by high expression of Gdf10. This territory is topologically the most caudal tier of the ventral pallium and accordingly, we named it Caudo-Ventral Pallium (CVP). In the absence of Pax6, the CVP is disrupted and Ebf3-expressing neurons fail to be generated. Overall, this work proposes a novel model of the neuronal composition of the medial amygdala and unravels for the first time a new novel pallial subpopulation originating from the CVP and expressing the transcription factor Ebf3.

Zinc finger protein 521 antagonizes early B-cell factor 1 and modulates the B-lymphoid differentiation of primary hematopoietic progenitors.

PubMed

Mega, Tiziana; Lupia, Michela; Amodio, Nicola; Horton, Sarah J; Mesuraca, Maria; Pelaggi, Daniela; Agosti, Valter; Grieco, Michele; Chiarella, Emanuela; Spina, Raffaella; Moore, Malcolm A S; Schuringa, Jan Jacob; Bond, Heather M; Morrone, Giovanni

2011-07-01

Zinc finger protein 521 (EHZF/ZNF521) is a multi-functional transcription co-factor containing 30 zinc fingers and an amino-terminal motif that binds to the nucleosome remodelling and histone deacetylase (NuRD) complex. ZNF521 is believed to be a relevant player in the regulation of the homeostasis of the hematopoietic stem/progenitor cell compartment, however the underlying molecular mechanisms are still largely unknown. Here, we show that this protein plays an important role in the control of B-cell development by inhibiting the activity of early B-cell factor-1 (EBF1), a master factor in B-lineage specification. In particular, our data demonstrate that: (1) ZNF521 binds to EBF1 via its carboxyl-terminal portion and this interaction is required for EBF1 inhibition; (2) NuRD complex recruitment by ZNF521 is not essential for the inhibition of transactivation of EBF1-dependent promoters; (3) ZNF521 represses EBF1 target genes in a human B-lymphoid molecular context; and (4) RNAi-mediated silencing of ZNF521/Zfp521 in primary human and murine hematopoietic progenitors strongly enhances the generation of B-lymphocytes in vitro. Taken together, our data indicate that ZNF521 can antagonize B-cell development and lend support to the notion that it may contribute to conserve the multipotency of primitive lympho-myeloid progenitors by preventing or delaying their EBF1-driven commitment toward the B-cell lineage.

Coordinated transcriptional regulation of bone homeostasis by Ebf1 and Zfp521 in both mesenchymal and hematopoietic lineages

PubMed Central

Kiviranta, Riku; Yamana, Kei; Saito, Hiroaki; Ho, Daniel K.; Laine, Julius; Tarkkonen, Kati; Nieminen-Pihala, Vappu; Hesse, Eric; Correa, Diego; Määttä, Jorma; Tessarollo, Lino; Rosen, Evan D.; Horne, William C.; Jenkins, Nancy A.; Copeland, Neal G.; Warming, Soren

2013-01-01

Bone homeostasis is maintained by the coupled actions of hematopoietic bone-resorbing osteoclasts (OCs) and mesenchymal bone-forming osteoblasts (OBs). Here we identify early B cell factor 1 (Ebf1) and the transcriptional coregulator Zfp521 as components of the machinery that regulates bone homeostasis through coordinated effects in both lineages. Deletion of Zfp521 in OBs led to impaired bone formation and increased OB-dependent osteoclastogenesis (OC-genesis), and deletion in hematopoietic cells revealed a strong cell-autonomous role for Zfp521 in OC progenitors. In adult mice, the effects of Zfp521 were largely caused by repression of Ebf1, and the bone phenotype of Zfp521+/− mice was rescued in Zfp521+/−:Ebf1+/− mice. Zfp521 interacted with Ebf1 and repressed its transcriptional activity. Accordingly, deletion of Zfp521 led to increased Ebf1 activity in OBs and OCs. In vivo, Ebf1 overexpression in OBs resulted in suppressed bone formation, similar to the phenotype seen after OB-targeted deletion of Zfp521. Conversely, Ebf1 deletion led to cell-autonomous defects in both OB-dependent and cell-intrinsic OC-genesis, a phenotype opposite to that of the Zfp521 knockout. Thus, we have identified the interplay between Zfp521 and Ebf1 as a novel rheostat for bone homeostasis. PMID:23569325

Do aphid colonies amplify their emission of alarm pheromone?

PubMed

Hatano, Eduardo; Kunert, Grit; Bartram, Stefan; Boland, Wilhelm; Gershenzon, Jonathan; Weisser, Wolfgang W

2008-09-01

When aphids are attacked by natural enemies, they emit alarm pheromone to alert conspecifics. For most aphids tested, (E)-beta-farnesene (EBF) is the main, or only, constituent of the alarm pheromone. In response to alarm pheromone, alerted aphids drop off the plant, walk away, or attempt to elude predators. However, under natural conditions, EBF concentration might be low due to the low amounts emitted, to rapid air movement, or to oxidative degradation. To ensure that conspecifics are warned, aphids might conceivably amplify the alarm signal by emitting EBF in response to EBF emitted by other aphids. To examine whether such amplification occurs, we synthesized deuterated EBF (DEBF), which allowed us to differentiate between applied and aphid-derived chemical. Colonies of Acyrthosiphon pisum were treated with DEBF, and headspace volatiles were collected and analyzed for evidence of aphid-derived EBF. No aphid-derived EBF was detected, suggesting that amplification of the alarm signal does not occur. We discuss the disadvantages of alarm signal reinforcement.

Modeling the Influence of Early Skin-to-Skin Contact on Exclusive Breastfeeding in a Sample of Hispanic Immigrant Women.

PubMed

Linares, Ana M; Wambach, Karen; Rayens, Mary K; Wiggins, Amanda; Coleman, Elizabeth; Dignan, Mark B

2017-10-01

Using data from a longitudinal study of breastfeeding in Hispanics, this study evaluated the influence of early skin-to-skin contact (SSC) on initiation and sustained exclusive breastfeeding (EBF) at 1 month postpartum. Two-thirds of the women in the sample participated in early SSC. At discharge, over half of the women were EBF; this proportion decreased to one-third at 1 month postpartum. Controlling for demographic and clinical variables in the model, participation in early SSC was associated with a greater than sevenfold increase in the odds of EBF at discharge (p = .005) but was not predictive of EBF at 1 month post-discharge (p = .7). Younger maternal age and increased prenatal infant feeding intention were associated with an increased likelihood of EBF across both timepoints. Promoting early SSC may help with initiation of EBF, while further breastfeeding support may be needed to maintain EBF following discharge for this vulnerable population.

Factors associated with intention to exclusive breastfeed in central women's hospital, Yangon, Myanmar.

PubMed

Hmone, Myat Pan; Li, Mu; Agho, Kingsley; Alam, Ashraful; Dibley, Michael J

2017-01-01

Under-nutrition is a public health problem in Myanmar. Despite current efforts, the exclusive breastfeeding rate (EBF) for children under six months is only 24%. Intention to breastfeed is a strong predictor for long-term breastfeeding, however, little is known about pregnant women's breastfeeding intentions in Myanmar. We, therefore, aimed to identify the factors associated with women's intention to EBF. Data in this article was collected in a baseline survey for a randomized controlled trial, which aimed to assess the impact of mobile text messages on the breastfeeding practices of women in Yangon, Myanmar. A total of 353 pregnant women at 28-34 weeks of gestation, recruited into the trial from the antenatal clinics of the Central Women's Hospital, Yangon, Myanmar, responded to the baseline survey questions, which included background information and breastfeeding related characteristics. To determine factors associated with women's intention to EBF logistic regression was used to analyse individual demographic, household economic and breastfeeding characteristics. In-depth interviews were performed with a sub-sample of 24 women who participated in the survey, to gain a further understanding of these associated factors. After adjusting for potential confounders, working women were less likely to intend to EBF (adjusted odds ratio (AOR) = 0.30, CI 0.17-0.53). Women from rich households (AOR = 2.43, CI 1.08-5.47) and middle income households (AOR = 1.79, CI 1.01-3.16); those who had high (AOR = 10.19, CI 3.43-30.23) and medium (AOR = 5.46, CI 1.79-16.72) breastfeeding knowledge levels, and received information from health professionals (AOR = 2.29, CI 1.29-4.03) and mobile internet (AOR 3.62, CI 2.04-6.41) had a higher intention to EBF. These findings were supported by qualitative analysis, which revealed that returning to work was the main barrier; health staff and printed media are reliable sources and; women with higher knowledge had high intentions to EBF. EBF intention was influenced by many factors. Breastfeeding promotion programs should target the poor, working women and women with lower breastfeeding knowledge. Breastfeeding education via health staff and the Internet, breastfeeding facilities at the work place and longer maternity leave in the private sector should all be encouraged. Australian New Zealand Clinical Trials Registry ACTRN12615000063516.

[Maintenance of exclusive breastfeeding after three months postpartum: An experience in a health department of a Valencian Community].

PubMed

Vila-Candel, Rafael; Soriano-Vidal, Francisco J; Murillo-Llorente, Mayte; Pérez-Bermejo, Marcelino; Castro-Sánchez, Enrique

2018-02-14

To investigate the prevalence of EBF at 3-months postpartum, and the early factors for discontinuation. Observational, retrospective study. Health department of La Ribera, Valencia, Spain. Newborns between December 2012 to January 2017. Pregnant women were interviewed at postpartum and at 3 months regarding variables associated with breastfeeding initiation and continuation, matched with socio-demographic and obstetric-neonatal information. Prevalence of breastfeeding at discharge and exclusive breastfeeding at 3 months. Reasons for interrupt exclusive breastfeeding. Chi-square determination between qualitative variables. One thousand three hundred and thirty-eighth women were recruited. EBF at discharge was 68.2% (913) and at 3 months 46.7% (625). EBF duration was 68.7±32.7 days (95% CI: 66.9-71.2). We found statistically significant differences between the type of breastfeeding and the variables, year of study, country of origin and parity (P<0.001, P=0.005 and P=0.05 respectively). Hypogalactia (21.8%) and lower than recommended increase in newborn weight gain (14.9%) were most frequent factors for discontinuation. The prevalence of EBF at 3 months is low compared to other similar studies, although we see an upward trend. Belief in hypogalactia influenced the maintenance of exclusive breastfeeding. Copyright © 2017 Elsevier España, S.L.U. All rights reserved.

Iron Status at Age 6 Months in Colombian Infants Exclusively Breast-fed for 4 to 5 Versus 6 Months.

PubMed

Olaya, Gilma A; Lawson, Margaret; Fewtrell, Mary

2017-03-01

The optimal age for introducing complementary feeding to breast-fed infants may differ depending on the setting. Prolonged exclusive breast-feeding (EBF) protects against infection but may increase the risk of iron deficiency (ID)/anaemia (IDA) in vulnerable infants. The aim of the present study was to compare haemoglobin (Hb), serum ferritin (SF), anaemia (Hb < 11 g/L), ID (SF < 12 μg/L) and IDA (Hb < 10.5 g/dL + Hct < 33% + ID) using observational analyses in 6-month old infants from Bogota, Colombia who were EBF for 4 to 5 versus 6 months or older, and examine predictors. Infant feeding was recorded, anthropometry performed, and blood obtained for Hb and SF at 6 months in healthy term infants (birth weight > 2500 g), all EBF for ≥4 months. One hundred eight infants (54% boys) were recruited; 46% EBF for 4 to 5 months, 54% EBF at 6 months. Prevalence of anaemia, ID, and IDA was 20%, 10%, and 5%, with no significant difference between EBF4-5 and EBF6 groups. In multivariate models, anaemia/ID were predicted by greater weight gain from 0 to 6 months, and anaemia also by caesarean delivery; Hb was lower in infants with higher intake of cows' milk; SF was lower in boys and those with greater weight gain. EBF4-5 versus EBF6 was not a significant predictor of any outcome. Anaemia and ID were common at 6 months but were not affected by EBF for 4 to 5 versus 6 months, suggesting 6 months EBF is safe in this population. Further research is, however, required to examine effects on later iron status. The findings highlight the need to emphasise avoidance of cow's milk before 12 months.

High Rates of Exclusive Breastfeeding in Both Arms of a Peer Counseling Study Promoting EBF Among HIV-Infected Kenyan Women.

PubMed

Bosire, Rose; Betz, Bourke; Aluisio, Adam; Hughes, James P; Nduati, Ruth; Kiarie, James; Chohan, Bhavna H; Merkel, Michele; Lohman-Payne, Barbara; John-Stewart, Grace; Farquhar, Carey

2016-03-01

Exclusive breastfeeding (EBF) is recommended for 6 months after delivery as the optimal infant feeding method and is especially important for prevention of mother-to-child HIV transmission (PMTCT). However, EBF promotion efforts among HIV-infected mothers in sub-Saharan Africa have achieved mixed success and require context-specific interventions. HIV-positive, pregnant women from six clinics in Nairobi were enrolled into a clinic-level, before-after counseling intervention study. All women received standard perinatal and HIV care. Women in the intervention arm were offered three counseling sessions that promoted EBF, described its benefits, and explained breastfeeding techniques. Mother-infant pairs were followed until 14 weeks postpartum, with infant HIV testing at 6 weeks. EBF prevalence at 14 weeks postpartum was compared between study arms using log-binomial regression. Proportions of 6-week HIV-free survival and 14-week infant survival were assessed using Cox regression. Risk estimates were adjusted for clinic, relationship status, and antiretroviral therapy. Between 2009 and 2013, 833 women were enrolled of whom 94% planned to practice EBF for 6 months and 95% were taking therapeutic or prophylactic antiretrovirals. Median age was 27 years; median CD4 count was 403 cells/μL. EBF prevalence at 14 weeks postpartum was 86% in the control and 81% in the intervention group (p = 0.19). No differences were observed between groups for 6-week HIV-free survival and 14-week infant survival. Women who received breastfeeding counseling were not more likely to breastfeed exclusively, in part due to high overall EBF prevalence in this study population. The high EBF prevalence is an important finding, given recent efforts to promote EBF in Kenya.

Addressing barriers to exclusive breast-feeding in low- and middle-income countries: a systematic review and programmatic implications.

PubMed

Kavle, Justine A; LaCroix, Elizabeth; Dau, Hallie; Engmann, Cyril

2017-12-01

Despite numerous global initiatives on breast-feeding, trend data show exclusive breast-feeding (EBF) rates have stagnated over the last two decades. The purpose of the present systematic review was to determine barriers to exclusive breast-feeding in twenty-five low- and middle-income countries and discuss implications for programmes. A search of Scopus, MEDLINE, CINAHL and PsychINFO was conducted to retrieve studies from January 2000 to October 2015. Using inclusion criteria, we selected both qualitative and quantitative studies that described barriers to EBF. Low- and middle-income countries. Following application of systematic review criteria, forty-eight articles from fourteen countries were included in the review. Sixteen barriers to EBF were identified in the review. There is moderate evidence of a negative association between maternal employment and EBF practices. Studies that examined EBF barriers at childbirth and the initial 24 h post-delivery found strong evidence that caesarean section can impede EBF. There is moderate evidence for early initiation of breast-feeding and likelihood of practising EBF. Breast-feeding problems were commonly reported from cross-sectional or observational studies. Counselling on EBF and the presence of family and/or community support have demonstrated improvements in EBF. Improving the counselling skills of health workers to address breast-feeding problems and increasing community support for breast-feeding are critical components of infant and young child feeding programming, which will aid in attaining the 2025 World Health Assembly EBF targets. Legislation and regulations on marketing of breast-milk substitutes, paid maternity leave and breast-feeding breaks for working mothers require attention in low- and middle-income countries.

Barriers to and Facilitators of Adherence to Exclusive Breastfeeding Practices Among HIV Infected and Non-Infected Women in Jos, Nigeria.

PubMed

Coetzee, Bronwynè; Tomlinson, Mark; Osawe, Sophia; Abimiku, Alash'le; Kagee, Ashraf

2017-04-01

Objectives In Nigeria adherence to exclusive breastfeeding (EBF) practices is currently suboptimal and a better understanding of the factors affecting adherence to EBF is needed. We sought to identify and delineate the barriers to and facilitators of adherence to EBF amongst HIV-infected and uninfected women in Nigeria. Methods We explored the barriers and facilitators to EBF amongst 37 (25 HIV-infected and 12 HIV-uninfected) pregnant women attending an antenatal clinic in Jos, Nigeria. In-depth interviews were conducted with each of the pregnant women in their third trimester of pregnancy and again 1 month after giving birth. Results The themes that emerged were mothers' feeding intentions, significant role players in the decision to breastfeed, perceived barriers (e.g. physiological issues, stigma, employment) and perceived facilitators (e.g. pleasure and enjoyment derived from breastfeeding, natural milk from God, disclosure and family support) associated with EBF. Conclusions Most women preferred EBF and offered it to their infants. However, more efforts are needed to improve support structures at home and at work to accommodate women who choose to do EBF.

Household food insecurity, maternal nutritional status, and infant feeding practices among HIV-infected Ugandan women receiving combination antiretroviral therapy

PubMed Central

YOUNG, Sera L.; PLENTY, Albert H. J.; LUWEDDE, Flavia A.; NATAMBA, Barnabas K.; NATUREEBA, Paul; ACHAN, Jane; MWESIGWA, Julia; RUEL, Theodore D.; ADES, Veronica; OSTERBAUER, Beth; CLARK, Tamara D.; DORSEY, Grant; CHARLEBOIS, Edwin D.; KAMYA, Moses; HAVLIR, Diane V.; COHAN, Deborah L.

2015-01-01

Objectives Household food insecurity may be a barrier to both optimal maternal nutritional status and infant feeding practices, but few studies have tested this relationship quantitatively, and never among HIV-infected individuals. We therefore explored if greater household food insecurity was associated with poorer maternal nutritional status, shorter duration of exclusive breastfeeding (EBF) and fewer animal-source complementary foods. Methods We assessed these outcomes among 180 HIV-infected pregnant and breastfeeding (BF) women receiving combination antiretroviral therapy in the PROMOTE trial (NCT00993031), a prospective, longitudinal cohort study in Tororo, Uganda. Results Household food insecurity was common; the prevalence of severe, moderate, and little to no household hunger was 7.3%, 40.5%, and 52.2%, respectively. Poor maternal nutritional status was common and women in households experiencing moderate to severe household hunger (MSHH) had statistically significantly lower BMIs at enrollment (21.3 vs 22.5, p<0.01) and prior to delivery (22.6 vs. 23.8, p<0.01). However, MSHH was not associated with maternal BMI or gestational weight gain in multivariate models. The prevalence (95% CI) of EBF at 6 months was 66.4% (59.0%-72.8%), and the proportion of women breastfeeding at 12 months was 80.0% (73.0%-85.3%).MSHH was not associated with EBF at 6 months or breastfeeding at 12 months. However, among those women still EBF at 4 months (81.0% of population), those experiencing MSHH were significantly more likely to cease EBF between 4 and 6 months (aHR: 2.52, 95% CI 1.03-6.19). Conclusions Interventions addressing household food insecurity, maternal malnutrition and suboptimal breastfeeding practices are urgently needed. PMID:24585398

Epstein-Barr virus exploits intrinsic B-lymphocyte transcription programs to achieve immortal cell growth.

PubMed

Zhao, Bo; Zou, James; Wang, Hongfang; Johannsen, Eric; Peng, Chih-wen; Quackenbush, John; Mar, Jessica C; Morton, Cynthia Casson; Freedman, Matthew L; Blacklow, Stephen C; Aster, Jon C; Bernstein, Bradley E; Kieff, Elliott

2011-09-06

Epstein-Barr virus nuclear antigen 2 (EBNA2) regulation of transcription through the cell transcription factor RBPJ is essential for resting B-lymphocyte (RBL) conversion to immortal lymphoblast cell lines (LCLs). ChIP-seq of EBNA2 and RBPJ sites in LCL DNA found EBNA2 at 5,151 and RBPJ at 10,529 sites. EBNA2 sites were enriched for RBPJ (78%), early B-cell factor (EBF, 39%), RUNX (43%), ETS (39%), NFκB (22%), and PU.1 (22%) motifs. These motif associations were confirmed by LCL RBPJ ChIP-seq finding 72% RBPJ occupancy and Encyclopedia Of DNA Elements LCL ChIP-seq finding EBF, NFκB RELA, and PU.1 at 54%, 31%, and 17% of EBNA2 sites. EBNA2 and RBPJ were predominantly at intergene and intron sites and only 14% at promoter sites. K-means clustering of EBNA2 site transcription factors identified RELA-ETS, EBF-RUNX, EBF, ETS, RBPJ, and repressive RUNX clusters, which ranked from highest to lowest in H3K4me1 signals and nucleosome depletion, indicative of active chromatin. Surprisingly, although quantitatively less, the same genome sites in RBLs exhibited similar high-level H3K4me1 signals and nucleosome depletion. The EBV genome also had an LMP1 promoter EBF site, which proved critical for EBNA2 activation. LCL HiC data mapped intergenic EBNA2 sites to EBNA2 up-regulated genes. FISH and chromatin conformation capture linked EBNA2/RBPJ enhancers 428 kb 5' of MYC to MYC. These data indicate that EBNA2 evolved to target RBL H3K4me1 modified, nucleosome-depleted, nonpromoter sites to drive B-lymphocyte proliferation in primary human infection. The primed RBL program likely supports antigen-induced proliferation.

Improving Exclusive Breastfeeding in an Urban Academic Hospital.

PubMed

Ward, Laura P; Williamson, Susan; Burke, Stephanie; Crawford-Hemphill, Ruby; Thompson, Amy M

2017-02-01

Breastfeeding has many well-established health benefits for infants and mothers. There is greater risk reduction in health outcomes with exclusive breastfeeding (EBF). Our urban academic facility has had long-standing low EBF rates, serving a population with breastfeeding disparities. We sought to improve EBF rates through a Learning Collaborative model by participating in the Best Fed Beginnings project. Formal improvement science methods were used, including the development of a key driver diagram and plan-do-study-act cycles. Improvement activities followed the Ten Steps to Successful Breastfeeding. We demonstrated significant improvement in the median adherence to 2 process measures, rooming in and skin-to-skin after delivery. Subsequently, the proportion of infants exclusively breastfed at hospital discharge in our facility increased from 37% to 59%. We demonstrated an increase in sustained breastfeeding in a subset of patients at a postpartum follow-up visit. These improvements led to Baby-Friendly designation at our facility. This quality improvement initiative resulted in a higher number of infants exclusively breastfed in our patient population at "high risk not to breastfeed." Other hospitals can use these described methods and techniques to improve their EBF rates. Copyright © 2017 by the American Academy of Pediatrics.

Factors influencing breastfeeding in children less than 2 years of age in Lao PDR.

PubMed

Putthakeo, Pornpai; Ali, Moazzam; Ito, Chiaki; Vilayhong, Panome; Kuroiwa, Chushi

2009-09-01

This study aimed to investigate the prevalence of, and factors influencing, exclusive breastfeeding (EBF) at 6 months and continued breastfeeding (CBF) at 2 years. Between January and February 2007, a cross-sectional study was conducted using a semi-structured questionnaire in 40 villages in the Vientiane capital and the Vientiane province of Lao PDR. A total of 400 mothers with children less than 2 years old were recruited by multistage random sampling. Based on the 1991 World Health Organization Breastfeeding Indicators, children were classified into three groups, 6-23-month-old children for assessing EBF at 6 months, 12-15-month-old children for CBF at 1 year and 20-23-month-old children for CBF at 2 years. The prevalence of EBF at 6 months and CBF at 2 years were 19.4% (n= 283) and 18.6% (n= 43), respectively. Some of the factors influencing EBF at 6 months in a univariate logistic regression model included: location of residence, (OR: 19.19, 95% CI 6.96-57.01), ethnicity (OR: 3.15, 95% CI 1.63-6.08), encouragement of the child's father (OR: 9.03, 95%CI 1.21-67.57) and inter-spousal communication (OR: 5.20, 95% CI 2.34-11.56). A majority of the mothers (75.0%) had watched television advertisements for infant formula from Thailand, and 48.4% reported that they wanted to buy formula milk after having watched them. This study showed a low prevalence of EBF at 6 months in the studied area in Lao PDR. Some of the factors that had a strong impact on EBF at 6 months included: location of residence, ethnicity, father's involvement, early breastfeeding plan, Mother's Card in antenatal care and television advertisement. There may be opportunities for government to review a range of policies relating to paternal involvement, antenatal care and formula advertising that could help to improve EBF rate.

Determinants of Exclusive Breast Feeding in sub-Saharan Africa: A Multilevel Approach.

PubMed

Yalçin, Siddika Songül; Berde, Anselm S; Yalçin, Suzan

2016-09-01

The study aimed to provide an overall picture of the general pattern of exclusive breast feeding (EBF) in sub-Saharan Africa (SSA) by examining maternal sociodemographic, antenatal and postnatal factors associated with EBF in the region, as well as explore countries variations in EBF rates. We utilised cross-sectional data from the Demographic Health Surveys in 27 SSA countries. Our study sample included 25 084 infants under 6 months of age. The key outcome variable was EBF in the last 24 h. Due to the hierarchical structure of the data, a multilevel logistic regression model was used to explore factors associated with EBF. The overall prevalence of EBF in SSA was 36.0%, the prevalence was highest in Rwanda and lowest in Gabon. In the multilevel regression model, factors that were associated with increased likelihood of EBF included secondary and above maternal education, mothers within the ages of 25-34 years, rural residence, richer household wealth quantile, 4+ antenatal care visit, delivering in a health facility, singleton births, female infants, early initiation of breast feeding (EIBF), and younger infants. However, countries with higher gross national income per capita had lower EBF rates. To achieve a substantial increase in EBF rates in SSA, breast-feeding interventions and policies should target all women but with more emphasis to mothers with younger age, low educational status, urban residence, poor status, multiple births, and male infants. In addition, there is a need to promote antenatal care utilisation, hospital deliveries, and EIBF. © 2016 John Wiley & Sons Ltd.

Applications for Gradient Metal Alloys Fabricated Using Additive Manufacturing

NASA Technical Reports Server (NTRS)

Hofmann, Douglas C.; Borgonia, John Paul C.; Dillon, Robert P.; Suh, Eric J.; Mulder, jerry L.; Gardner, Paul B.

2013-01-01

Recently, additive manufacturing (AM) techniques have been developed that may shift the paradigm of traditional metal production by allowing complex net-shaped hardware to be built up layer-by-layer, rather than being machined from a billet. The AM process is ubiquitous with polymers due to their low melting temperatures, fast curing, and controllable viscosity, and 3D printers are widely available as commercial or consumer products. 3D printing with metals is inherently more complicated than with polymers due to their higher melting temperatures and reactivity with air, particularly when heated or molten. The process generally requires a high-power laser or other focused heat source, like an electron beam, for precise melting and deposition. Several promising metal AM techniques have been developed, including laser deposition (also called laser engineered net shaping or LENS® and laser deposition technology (LDT)), direct metal laser sintering (DMLS), and electron beam free-form (EBF). These machines typically use powders or wire feedstock that are melted and deposited using a laser or electron beam. Complex net-shape parts have been widely demonstrated using these (and other) AM techniques and the process appears to be a promising alternative to machining in some cases. Rather than simply competing with traditional machining for cost and time savings, the true advantage of AM involves the fabrication of hardware that cannot be produced using other techniques. This could include parts with "blind" features (like foams or trusses), parts that are difficult to machine conventionally, or parts made from materials that do not exist in bulk forms. In this work, the inventors identify that several AM techniques can be used to develop metal parts that change composition from one location in the part to another, allowing for complete control over the mechanical or physical properties. This changes the paradigm for conventional metal fabrication, which relies on an assortment of "post-processing" methods to locally alter properties (such as coating, heat treating, work hardening, shot peening, etching, anodizing, among others). Building the final part in an additive process allows for the development of an entirely new class of metals, so-called "functionally graded metals" or "gradient alloys." By carefully blending feedstock materials with different properties in an AM process, hardware can be developed with properties that cannot be obtained using other techniques but with the added benefit of the net-shaped fabrication that AM allows.

Traditional oral remedies and perceived breast milk insufficiency are major barriers to exclusive breastfeeding in rural Zimbabwe.

PubMed

Desai, Amy; Mbuya, Mduduzi N N; Chigumira, Ancikaria; Chasekwa, Bernard; Humphrey, Jean H; Moulton, Lawrence H; Pelto, Gretel; Gerema, Grace; Stoltzfus, Rebecca J

2014-07-01

Only 5.8% of Zimbabwean infants are exclusively breastfed for the first 6 mo of life despite substantial investment in exclusive breastfeeding (EBF) promotion throughout the country. We conducted a survey of 295 mothers of infants <6 mo of age who were recruited from rural immunization clinics and outreach sites in the Midlands Province of Zimbabwe. We explored infant feeding knowledge, beliefs and attitudes, and details regarding facilitators for EBF mothers and first foods fed by non-EBF mothers to identify and understand barriers to EBF. Among mothers of infants <1 mo, 1 to <2 mo, and 2-6 mo of age, 54%, 30%, and 12%, respectively, were practicing EBF. In adjusted multivariate analyses, EBF practice was positively associated with belief in the sufficiency of EBF (P = 0.05), belief in the avoidance of cooking oil feeding (a common traditional practice) in the first 6 mo (P = 0.001), and perceived pressure from others regarding infant feeding and traditional medicine use (P = 0.03). Psychosocial support and viewing breast milk as sufficient were reported as primary facilitators of EBF practice. Maternal responses to open-ended questions identified protection, nutrition, and crying as the main reasons for EBF interruption. During the first 2 mo of life, "protection feedings" using traditional oral remedies (such as cooking oil and water) to prevent or treat perceived illness, specifically colic and sunken/depressed fontanel, made up 78.5% of the non-breast milk feeds. From the second month of life, "nutrition feedings," mainly of water and porridge, were given when mothers believed their breast milk was insufficient in quantity or quality to meet the hunger or thirst needs of their infants. Our findings underscore the importance of exploring cultural beliefs and practices as they pertain to infant feeding and care and present insights for designing and targeting EBF promotion interventions. © 2014 American Society for Nutrition.

Economic determinants of breastfeeding in Haiti: The effects of poverty, food insecurity, and employment on exclusive breastfeeding in an urban population.

PubMed

Lesorogol, Carolyn; Bond, Caitlin; Dulience, Sherlie Jean Louis; Iannotti, Lora

2018-04-01

There is limited and inconsistent empirical evidence regarding the role of economic factors in breastfeeding practices, globally. Studies have found both negative and positive associations between low income and exclusive breastfeeding (EBF). Employment, which should improve household income, may reduce EBF due to separation of mother and infant. In the context of a randomized controlled study of lipid-based complementary feeding in an urban slum in Cap Haitien, Haiti, we examined the economic factors influencing breastfeeding practices using mixed methods. Findings demonstrate relationships between urban context, economic factors, and breastfeeding practices. Poverty, food insecurity, time constraints, and limited social support create challenges for EBF. Maternal employment is associated with lower rates of EBF and less frequent breastfeeding. Extreme food insecurity sometimes leads to increased exclusive breastfeeding among Haitian mothers, what we call "last resort EBF." In this case, women practice EBF because they have no alternative food source for the infant. Suggested policies and programs to address economic constraints and promote EBF in this population include maternal and child allowances, quality child care options, and small-scale household urban food production. © 2017 John Wiley & Sons Ltd.

Expansion of banana (Musa acuminata) gene families involved in ethylene biosynthesis and signalling after lineage-specific whole-genome duplications.

PubMed

Jourda, Cyril; Cardi, Céline; Mbéguié-A-Mbéguié, Didier; Bocs, Stéphanie; Garsmeur, Olivier; D'Hont, Angélique; Yahiaoui, Nabila

2014-05-01

Whole-genome duplications (WGDs) are widespread in plants, and three lineage-specific WGDs occurred in the banana (Musa acuminata) genome. Here, we analysed the impact of WGDs on the evolution of banana gene families involved in ethylene biosynthesis and signalling, a key pathway for banana fruit ripening. Banana ethylene pathway genes were identified using comparative genomics approaches and their duplication modes and expression profiles were analysed. Seven out of 10 banana ethylene gene families evolved through WGD and four of them (1-aminocyclopropane-1-carboxylate synthase (ACS), ethylene-insensitive 3-like (EIL), ethylene-insensitive 3-binding F-box (EBF) and ethylene response factor (ERF)) were preferentially retained. Banana orthologues of AtEIN3 and AtEIL1, two major genes for ethylene signalling in Arabidopsis, were particularly expanded. This expansion was paralleled by that of EBF genes which are responsible for control of EIL protein levels. Gene expression profiles in banana fruits suggested functional redundancy for several MaEBF and MaEIL genes derived from WGD and subfunctionalization for some of them. We propose that EIL and EBF genes were co-retained after WGD in banana to maintain balanced control of EIL protein levels and thus avoid detrimental effects of constitutive ethylene signalling. In the course of evolution, subfunctionalization was favoured to promote finer control of ethylene signalling. © 2014 CIRAD New Phytologist © 2014 New Phytologist Trust.

Exclusive breastfeeding reduces risk of mortality in infants up to 6 mo of age born to HIV-positive Tanzanian women.

PubMed

Natchu, Uma Chandra Mouli; Liu, Enju; Duggan, Christopher; Msamanga, Gernard; Peterson, Karen; Aboud, Said; Spiegelman, Donna; Fawzi, Wafaie W

2012-11-01

Despite the benefits of exclusive breastfeeding (EBF), exposure to HIV from breast milk has relegated EBF to an option only when formula feeding is not affordable, feasible, safe, and sustainable. Mixed feeding remains the norm in sub-Saharan Africa. We evaluated whether the duration of EBF was associated with mortality and HIV infection in children followed to ≤5 y of age. A total of 690 mother-infant pairs from the Trial of Vitamins with information on infant feeding, HIV status, and at least one visit in the first year were included in the analysis. The duration of EBF was defined in months as a time-varying covariate at each follow-up visit. Associations of the duration of EBF with mortality, HIV infection, and HIV infection or death were estimated by using Cox proportional hazards models and Kaplan-Meier survival curves. A 1-mo increase in EBF was associated with a 49% reduction in early infant mortality in the first 6 mo of life (RR: 0.51; 95% CI: 0.28, 0.93) and a nonsignificant 15% reduction in risk of HIV infection or death (RR: 0.85; 95% CI: 0.71, 1.01; P = 0.07) over the first 5 y of life. EBF was not associated with HIV infection (RR: 0.93; 95% CI: 0.76, 1.15). Longer EBF by HIV-positive mothers was associated with reduced mortality in the first 6 mo of life without increased HIV infection, which makes EBF the best option for women who cannot sustain exclusive formula feeding. This trial was registered at clinicaltrials.gov as NCT00197743.

Effect of infant feeding practices on iron status in a cohort study of Bolivian infants.

PubMed

Burke, Rachel M; Rebolledo, Paulina A; Aceituno, Anna M; Revollo, Rita; Iñiguez, Volga; Klein, Mitchel; Drews-Botsch, Carolyn; Leon, Juan S; Suchdev, Parminder S

2018-03-12

Iron deficiency (ID) is the most common micronutrient deficiency worldwide, with potentially severe consequences on child neurodevelopment. Though exclusive breastfeeding (EBF) is recommended for 6 months, breast milk has low iron content. This study aimed to estimate the effect of the length of EBF on iron status at 6 - 8 months of age among a cohort of Bolivian infants. Mother-infant pairs were recruited from 2 hospitals in El Alto, Bolivia, and followed from one through 6 - 8 months of age. Singleton infants > 34 weeks gestational age, iron-sufficient at baseline, and completing blood draws at 2 and 6 - 8 months of age were eligible for inclusion (N = 270). Ferritin was corrected for the effect of inflammation. ID was defined as inflammation-corrected ferritin < 12 μg/L, and anemia was defined as altitude-corrected hemoglobin < 11 g/dL; IDA was defined as ID plus anemia. The effect of length of EBF (infant received only breast milk with no other liquids or solids, categorized as < 4, 4 - 6, and > 6 months) was assessed for ID, IDA, and anemia (logistic regression) and ferritin (Fer) and hemoglobin (Hb, linear regression). Low iron status was common among infants at 6 - 8 months: 56% of infants were ID, 76% were anemic, and 46% had IDA. EBF of 4 months and above was significantly associated with ID as compared with EBF <  4 months (4 - 6 months: OR 2.0 [1.1 - 3.4]; > 6 months: 3.3 [1.0 - 12.3]), but not with IDA (4 - 6 months: OR 1.4 [0.8 - 2.4]; > 6 months: 2.2 [0.7 - 7.4]), or anemia (4 - 6 months: OR 1.4 [0.7 - 2.5]; > 6 months: 1.5 [0.7 - 7.2]). Fer and Hb concentrations were significantly lower with increasing months of EBF. Results suggest a relationship between prolonged EBF and ID, but are not sufficient to support changes to current breastfeeding recommendations. More research is needed in diverse populations, including exploration of early interventions to address infant IDA.

Semi empirical formula for exposure buildup factors

NASA Astrophysics Data System (ADS)

Seenappa, L.; Manjunatha, H. C.; Sridhar, K. N.; Hanumantharayappa, Chikka

2017-10-01

The nuclear data of photon buildup factor is an important concept that must be considered in nuclear safety aspects such as radiation shielding and dosimetry. The buildup factor is a coefficient that represents the contribution of collided photons with the target medium. Present work formulated a semi empirical formulae for exposure buildup factors (EBF) in the energy region 0.015-15 MeV, atomic number range 1 ≤ Z ≤ 92 and for mean free path up to 40 mfp. The EBFs produced by the present formula are compared with that of data available in the literature. It is found that present work agree with literature. This formula is first of its kind to calculate EBFs without using geometric progression fitting parameters. This formula may also use to calculate EBFs for compounds/mixtures/Biological samples. The present formula is useful in producing EBFs for elements and mixtures quickly. This semi empirical formula finds importance in the calculations of EBFs which intern helps in the radiation protection and dosimetry.

Effects of breastfeeding on weight loss and recovery of pregestational weight in adolescent and adult mothers.

PubMed

Sámano, Reyna; Martínez-Rojano, Hugo; Godínez Martínez, Estela; Sánchez Jiménez, Bernarda; Villeda Rodríguez, Gilda Paulina; Pérez Zamora, Julieta; Casanueva, Esther

2013-06-01

Exclusive breastfeeding (EBF) in adolescent mothers has been associated with greater postpartum maternal weight loss. To assess the associations between EBF and weight loss in adolescent and adult mothers and between EBF and weight and length gain of their children. A cohort of 68 adolescent mothers (15 to 19 years), 64 adult mothers (20 to 29 years), and their infants were studied. Anthropometric measurements were performed at 15, 90, 180, and 365 days postpartum in the mothers and children. EBF was defined as consumption of human milk without supplementation of any type (water, juice, nonhuman milk, or food) for 4 months. Sixty-five percent of mothers sustained EBF for 4 months. There were no significant differences in the weight or length of the infants of adolescent and adult mothers at 365 days postpartum. Among infants of adult mothers, there was a significant difference between the weight gain of those were exclusively breastfed and those who were not exclusively breastfed (6,498 +/- 1,060 vs 6,096 +/- 1,035 g, p < .050) at 365 days postpartum, according to the parameters for weight gain and length established by the World Health Organization (WHO). Among both adult and adolescent mothers, those who practiced EBF lost more weight than those who did not practice EBF (-2.9 kg, 95% interquartile range, -5.7 to 0.8 kg, vs -1.8 kg 95% interquartile range -2.8 to 2.2 kg; p = .004). Gestational weight gain, duration of EBF, and recovery menstruation explained 21% of the variance (F = 28.184, p = .001) in change in postpartum maternal weight (in kilograms) from 0 to 365 days postpartum in all mothers. Pregestational weight, duration of EBF, and maternal age were factors that explained 14% (F = 22.759, p = .001) of the change in the weight and length of the infants from 0 to 365 days of life. EBF in adolescent and adult mothers influences postpartum weight loss and provides adequate infant growth in accordance with the WHO 2006 standards.

Determinants of exclusive breastfeeding: a study of two sub-districts in the Atwima Nwabiagya District of Ghana.

PubMed

Ayawine, Alice; Ae-Ngibise, Kenneth Ayuurebobi

2015-01-01

Optimal breastfeeding rates have not been encouraging globally with sub-optimal feeding being customized in Sub-Saharan Africa. However, in the Atwima Nwabiagya district of Ghana, the message of Exclusive Breastfeeding (EBF) has caught up well with many nursing mothers. we examined the determinants of EBF vis-à-vis performance of a community based growth promotion strategy in the Atwima Nwabiagya district of the Ashanti region of Ghana. The study employed a cross-sectional comparative study design to analyze the impact of a community based growth promotion strategy on exclusive breast feeding in Abuakwa and Barekese, both in the Atwima Nwabiagya district of Ghana. Simple random sampling was used to select three communities each from the two sub-districts. Data collection tool employed was a standard questionnaire consisting of closed-ended questions. The variables were EBF knowledge level of mothers, cultural practices affecting EBF practice, occupational hindrances and the level of community participation in EBF activities. In all three hundred (300) nursing mothers of babies (0-12 months) were purposively interviewed. Results showed that mother's level of knowledge about EBF was good as such the practice was high. In addition, cultural practices in the area did not deter mothers from practicing exclusive breastfeeding. Two factors were associated with EBF in the univariate logistic model. Unmarried mothers were less likely to practice EB compared with mothers who were married (OR = 0.46, 95% 0.28, 0.77). Also the duration of breast feeding was associated wit EBF. The adjusted odds ratio was 0.41(95% CI: 0.32, 0.54) in favor of three months compared with six months. The Community Based Growth Promotion strategy has had a positive impact on the practice of EBF in the district. It is recommended that the collapsed initiative be reawaken if the stakes are to be maintained. There is also the need to address mothers' occupational needs and effective breastfeeding practices as this emerged as a major set-back to the practice of EBF among the participants.

Determinants of exclusive breastfeeding: a study of two sub-districts in the Atwima Nwabiagya District of Ghana

PubMed Central

Ayawine, Alice; Ae-Ngibise, Kenneth Ayuurebobi

2015-01-01

Introduction Optimal breastfeeding rates have not been encouraging globally with sub-optimal feeding being customized in Sub-Saharan Africa. However, in the Atwima Nwabiagya district of Ghana, the message of Exclusive Breastfeeding (EBF) has caught up well with many nursing mothers. we examined the determinants of EBF vis-à-vis performance of a community based growth promotion strategy in the Atwima Nwabiagya district of the Ashanti region of Ghana. Methods The study employed a cross-sectional comparative study design to analyze the impact of a community based growth promotion strategy on exclusive breast feeding in Abuakwa and Barekese, both in the Atwima Nwabiagya district of Ghana. Simple random sampling was used to select three communities each from the two sub-districts. Data collection tool employed was a standard questionnaire consisting of closed-ended questions. The variables were EBF knowledge level of mothers, cultural practices affecting EBF practice, occupational hindrances and the level of community participation in EBF activities. Results In all three hundred (300) nursing mothers of babies (0-12 months) were purposively interviewed. Results showed that mother's level of knowledge about EBF was good as such the practice was high. In addition, cultural practices in the area did not deter mothers from practicing exclusive breastfeeding. Two factors were associated with EBF in the univariate logistic model. Unmarried mothers were less likely to practice EB compared with mothers who were married (OR = 0.46, 95% 0.28, 0.77). Also the duration of breast feeding was associated wit EBF. The adjusted odds ratio was 0.41(95% CI: 0.32, 0.54) in favor of three months compared with six months. Conclusion The Community Based Growth Promotion strategy has had a positive impact on the practice of EBF in the district. It is recommended that the collapsed initiative be reawaken if the stakes are to be maintained. There is also the need to address mothers’ occupational needs and effective breastfeeding practices as this emerged as a major set-back to the practice of EBF among the participants. PMID:26958111

Household food insecurity, maternal nutritional status, and infant feeding practices among HIV-infected Ugandan women receiving combination antiretroviral therapy.

PubMed

Young, Sera L; Plenty, Albert H J; Luwedde, Flavia A; Natamba, Barnabas K; Natureeba, Paul; Achan, Jane; Mwesigwa, Julia; Ruel, Theodore D; Ades, Veronica; Osterbauer, Beth; Clark, Tamara D; Dorsey, Grant; Charlebois, Edwin D; Kamya, Moses; Havlir, Diane V; Cohan, Deborah L

2014-11-01

Household food insecurity (HHFI) may be a barrier to both optimal maternal nutritional status and infant feeding practices, but few studies have tested this relationship quantitatively, and never among HIV-infected individuals. We therefore described the prevalence of HHFI and explored if it was associated with poorer maternal nutritional status, shorter duration of exclusive breastfeeding (EBF) and fewer animal-source complementary foods. We assessed these outcomes using bivariate and multivariate analyses among 178 HIV-infected pregnant and breastfeeding (BF) women receiving combination antiretroviral therapy in the PROMOTE trial (NCT00993031), a prospective, longitudinal cohort study in Tororo, Uganda. HHFI was common; the prevalence of severe, moderate, and little to no household hunger was 7.3, 39.9, and 52.8 %, respectively. Poor maternal nutritional status was common and women in households experiencing moderate to severe household hunger (MSHH) had statistically significantly lower body mass index (BMIs) at enrollment (21.3 vs. 22.5, p < 0.01) and prior to delivery (22.6 vs. 23.8, p < 0.01). BMI across time during pregnancy, but not gestational weight gain, was significantly lower for MSHH [adjusted beta (95 % CI) -0.79 (-1.56, -0.02), p = 0.04; -2.06 (-4.31, 0.19), p = 0.07], respectively. The prevalence (95 % CI) of EBF at 6 months was 67.2 % (59.7-73.5 %), and the proportion of women BF at 12 months was 80.4 % (73.3-85.7 %). MSHH was not associated with prevalence of EBF at 6 months or BF at 12 months. However, among those women still EBF at 4 months (81.4 % of population), those experiencing MSHH were significantly more likely to cease EBF between 4 and 6 months (aHR 2.38, 95 % CI 1.02-5.58). The prevalence of HHFI, maternal malnutrition, and suboptimal infant feeding practices are high and the causal relationships among these phenomena must be further explored.

Mothers' education and ANC visit improved exclusive breastfeeding in Dabat Health and Demographic Surveillance System Site, northwest Ethiopia.

PubMed

Tariku, Amare; Alemu, Kassahun; Gizaw, Zemichael; Muchie, Kindie Fentahun; Derso, Terefe; Abebe, Solomon Mekonnen; Yitayal, Mezgebu; Fekadu, Abel; Ayele, Tadesse Awoke; Alemayehu, Geta Asrade; Tsegaye, Adino Tesfahun; Shimeka, Alemayehu; Biks, Gashaw Andargie

2017-01-01

Despite its proven benefit in reducing child mortality and morbidity, the coverage of exclusive breastfeeding (EBF) remains sub-optimal. In Ethiopia, about 52% of infants under six months of age were exclusively breastfed, implying the need for further identification of the barriers to optimal EBF practice. Therefore, this study aimed to investigate EBF and its determinants in the predominantly rural northwest Ethiopia. The study was conducted at the Dabat Health and Demographic Surveillance System (HDSS) site, which is located in Dabat District, northwest Ethiopia. A total of 5,227 mothers with children under five years of age were included for analysis. Multivariable binary logistic regression analysis was employed to identify factors associated with EBF. The Adjusted Odds Ratio (AOR) with a 95% Confidence Interval (CI) was estimated to show the strength of association. A P-value of <0.05 was used to declare statistical significance. About 54.5% [95% CI: 51.9, 57.1] of the mothers practiced EBF. Mothers' education [AOR = 2.10; 95% CI: 1.63, 2.71], age (20-35 years) [AOR = 1.39; CI: 1.07, 1.80], urban residence [AOR = 1.28; 95% CI: 1.07, 1.54], at least one ANC visit [AOR = 1.41; 95% CI: 1.23,1.61], initiation of breastfeeding within one hour of birth [AOR = 1.32; 95% CI: 1.15,1.50], richer household [AOR = 1.34; 95% CI: 1.07, 1.65], and withholding prelacteal feeds [AOR = 1.34; 95% CI: 1.17, 1.53] were found important determinants of EBF. In this study area, the prevalence of EBF is lower than the national as well as the global recommendation for universal coverage of EBF. Therefore, strengthening the implementation of Infant and Young Child Feeding strategy (IYCF) and maternal health care utilization are essential for stepping up EBF coverage. Moreover, attention should be given to uneducated, rural resident, and adolescent mothers.

Perceptions and practice of exclusive breastfeeding among Malay women in Kelantan, Malaysia: a qualitative approach.

PubMed

Tengku, Alina T I; Wan, Abdul Manan W M; Zaharah, S; Rohana, A J; Nik Normanieza, N M

2012-04-01

Despite evidence from various studies on exclusive breastfeeding (EBF) being best for infants, many women do not or are unable to practise EBF. This study aimed to examine perceptions on EBF and its influencing factors among a sample of Malay women in rural and urban areas in Kelantan, Malaysia. A qualitative study using in-depth interviews was conducted to examine respondents' views about EBF including their beliefs, experiences and feelings. The interviews were audio-recorded and transcribed verbatim, followed by discussion and identification of emergent concepts. Data saturation was achieved after interviewing a total of 30 women. The mean age of the women was about 30 years with most having at least secondary level schooling; the majority were working women. Thirteen of the 30 women practised EBF. They believed breastfeeding allowed them to fulfill their reproductive role and regarded it as a gift from God. The practice required sacrifice, and was therefore associated with a combination of positive and negative feelings. Differing opinions surfaced with regard to belief in the superiority of breastfeeding and feasibility of practice. Many women accepted breastfeeding practice but found it challenging to practise EBF especially when confronted with low milk production, perceived low nutritional quality breast milk, and work commitments. Women should be educated on the importance of EBF with regard to the nutritional adequacy of breast milk and long-term benefits for mother and children.

Breast-feeding in South Korea: factors influencing its initiation and duration.

PubMed

Chung, Woojin; Kim, Hanjoong; Nam, Chung-Mo

2008-03-01

To investigate factors influencing the practices of partial breast-feeding (PBF) and exclusive breast-feeding (EBF). A national, cross-sectional survey was conducted among married women aged 15-49 years from May to August 2003. South Korea. A total of 865 mothers answered questions regarding the feeding practices of their youngest baby, born between January 2001 and May 2003. The initiation rates of PBF and EBF were 81% and 63%, respectively. However, the median durations of PBF and EBF were very short: 12 and 8 weeks, respectively. According to stepwise logistic and Cox regression analyses, the more prenatal care women received, the more likely they were to initiate PBF and EBF but the less likely to continue EBF. Delivery by Caesarean section decreased the initiation of PBF and EBF. The mother's education level and employment status before marriage, the amount of prenatal care, delivery method and baby's status at birth affected breast-feeding initiation, whereas the amount of prenatal care influenced breast-feeding duration. To promote breast-feeding, education and campaigning on the importance of continued breast-feeding should be provided to the general public, particularly to health workers in maternity units.

Computer-aided rational design of novel EBF analogues with an aromatic ring.

PubMed

Wang, Shanshan; Sun, Yufeng; Du, Shaoqing; Qin, Yaoguo; Duan, Hongxia; Yang, Xinling

2016-06-01

Odorant binding proteins (OBPs) are important in insect olfactory recognition. These proteins bind specifically to insect semiochemicals and induce their seeking, mating, and alarm behaviors. Molecular docking and molecular dynamics simulations were performed to provide computational insight into the interaction mode between AgamOBP7 and novel (E)-β-farnesene (EBF) analogues with an aromatic ring. The ligand-binding cavity in OBP7 was found to be mostly hydrophobic due to the presence of several nonpolar residues. The interactions between the EBF analogues and the hydrophobic residues in the binding cavity increased in strength as the distance between them decreased. The EBF analogues with an N-methyl formamide or ester linkage had higher docking scores than those with an amide linkage. Moreover, delocalized π-π and electrostatic interactions were found to contribute significantly to the binding between the ligand benzene ring and nearby protein residues. To design new compounds with higher activity, four EBF analogues D1-D4 with a benzene ring were synthesized and evaluated based on their docking scores and binding affinities. D2, which had an N-methyl formamide group linkage, exhibited stronger binding than D1, which had an amide linkage. D4 exhibited particularly strong binding due to multiple hydrophobic interactions with the protein. This study provides crucial foundations for designing novel EBF analogues based on the OBP structure. Graphical abstract The design strategy of new EBF analogues based on the OBP7 structure.

Early skin-to-skin contact and breast-feeding behavior in term neonates: a randomized controlled trial.

PubMed

Thukral, Anu; Sankar, Mari Jeeva; Agarwal, Ramesh; Gupta, Nandita; Deorari, Ashok K; Paul, Vinod K

2012-01-01

To evaluate if early skin-to-skin contact (SSC) improves breast-feeding (BF) behavior and exclusive BF (EBF) rates in term infants at 48 h of age. Term infants born by normal delivery were randomized at birth to either early SSC (n = 20) or conventional care (controls; n = 21). SSC was continued for at least 2 h after birth. Subsequently, one BF session of the infants was video recorded at about 48 h of life. The primary outcome, infants' BF behavior at 48 h of life, was assessed using the modified infant Breast-Feeding Assessment Tool (BAT; a score consisting of infant's readiness to feed, sucking, rooting and latching, each item scored from 0 to 3) by three independent masked observers. The secondary outcomes were EBF rates at 48 h and 6 weeks of age and salivary cortisol level of infants at 6 h of age. Baseline characteristics including birth weight and gestation were comparable between the two groups. There was no significant difference in the BAT scores between the groups [median: 8, interquartile range (IQR) 5-10 vs. median 9, IQR 5-10; p = 0.6]. EBF rates at 48 h and at 6 weeks were, however, significantly higher in the early-SSC group than in the control group [95.0 vs. 38.1%; relative risk (RR): 2.5, 95% confidence interval (95% CI): 1.4-4.3 and 90 vs. 28.6%; RR: 3.2, 95% CI: 1.6-6.3]. Early SSC did not improve BF behavior at discharge but significantly improved the EBF rates of term neonates. Copyright © 2012 S. Karger AG, Basel.

Cascade of kinetic energy and scalar variance in DC electrokinetic turbulence

NASA Astrophysics Data System (ADS)

Zhao, Wei; Wang, Guiren

2017-11-01

Turbulent flow can be generated by DC electrokinetic (EK) force based on the electric conductivity and permittivity variations in fluids, as have been demonstrated by Varshney et al (2016), where a -1.4 slope of velocity power spectrum is observed. Here, we theoretically found the scaling exponents of velocity and scalar structures in the electric-body-force (EBF) dominant subregion of DC EK turbulence were 2/5 (equivalent to the -7/5 slope of velocity power spectrum) and 4/5 respectively. The theory perfectly explains the experimental results of Varshney et al. (2016). Based on Kármán-Howarth equation with forcing terms, the energy cascade process of DC EK turbulence was also investigated. Depending on the electric Rayleigh number (Rae) , two different energy cascade processes may happen. When Rae is small, the kinetic energy cascades along inertial subregion and EBF dominant subregion in sequence, before it is dissipated by fluid viscosity. When Rae is sufficiently large, the inertial subregion may be absent with EBF dominant subregion left. This investigation is very important on understand EK turbulence, which could be widely existed in nature and applied in engineerings. The work was supported by NSFC (11672229), and NSF (CAREER CBET-0954977 and MRI CBET-1040227).

Structural Determination of Functional Domains in Early B-cell Factor (EBF) Family of Transcription Factors Reveals Similarities to Rel DNA-binding Proteins and a Novel Dimerization Motif*

PubMed Central

Siponen, Marina I.; Wisniewska, Magdalena; Lehtiö, Lari; Johansson, Ida; Svensson, Linda; Raszewski, Grzegorz; Nilsson, Lennart; Sigvardsson, Mikael; Berglund, Helena

2010-01-01

The early B-cell factor (EBF) transcription factors are central regulators of development in several organs and tissues. This protein family shows low sequence similarity to other protein families, which is why structural information for the functional domains of these proteins is crucial to understand their biochemical features. We have used a modular approach to determine the crystal structures of the structured domains in the EBF family. The DNA binding domain reveals a striking resemblance to the DNA binding domains of the Rel homology superfamily of transcription factors but contains a unique zinc binding structure, termed zinc knuckle. Further the EBF proteins contain an IPT/TIG domain and an atypical helix-loop-helix domain with a novel type of dimerization motif. The data presented here provide insights into unique structural features of the EBF proteins and open possibilities for detailed molecular investigations of this important transcription factor family. PMID:20592035

Externally blown flap noise research

NASA Technical Reports Server (NTRS)

Dorsch, R. G.

1974-01-01

The Lewis Research Center cold-flow model externally blown flap (EBF) noise research test program is summarized. Both engine under-the-wing and over-the-wing EBF wing section configurations were studied. Ten large scale and nineteen small scale EBF models were tested. A limited number of forward airspeed effect and flap noise suppression tests were also run. The key results and conclusions drawn from the flap noise tests are summarized and discussed.

Application of Data-Driven Evidential Belief Functions to Prospectivity Mapping for Aquamarine-Bearing Pegmatites, Lundazi District, Zambia

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carranza, E. J. M., E-mail: carranza@itc.nl; Woldai, T.; Chikambwe, E. M.

A case application of data-driven estimation of evidential belief functions (EBFs) is demonstrated to prospectivity mapping in Lundazi district (eastern Zambia). Spatial data used to represent recognition criteria of prospectivity for aquamarine-bearing pegmatites include mapped granites, mapped faults/fractures, mapped shear zones, and radioelement concentration ratios derived from gridded airborne radiometric data. Data-driven estimates EBFs take into account not only (a) spatial association between an evidential map layer and target deposits but also (b) spatial relationships between classes of evidences in an evidential map layer. Data-driven estimates of EBFs can indicate which spatial data provide positive or negative evidence of prospectivity.more » Data-driven estimates of EBFs of only spatial data providing positive evidence of prospectivity were integrated according to Dempster's rule of combination. Map of integrated degrees of belief was used to delineate zones of relative degress of prospectivity for aquamarine-bearing pegmatites. The predictive map has at least 85% prediction rate and at least 79% success rate of delineating training and validation deposits, respectively. The results illustrate usefulness of data-driven estimation of EBFs in GIS-based predictive mapping of mineral prospectivity. The results also show usefulness of EBFs in managing uncertainties associated with evidential maps.« less

Impact of a peer-counseling intervention on breastfeeding practices in different socioeconomic strata: results from the equity analysis of the PROMISE-EBF trial in Uganda.

PubMed

Eide, Kristiane Tislevoll; Fadnes, Lars Thore; Engebretsen, Ingunn Marie Stadskleiv; Onarheim, Kristine Husøy; Wamani, Henry; Tumwine, James K; Norheim, Ole Frithjof

2016-01-01

Undernutrition is highly prevalent among infants in Uganda. Optimal infant feeding practices may improve nutritional status, health, and survival among children. Our study evaluates the socioeconomic distribution of exclusive breastfeeding (EBF) and growth outcomes among infants included in a trial, which promoted EBF by peer counselors in Uganda. Twenty-four clusters comprising one to two communities in Uganda were randomized into intervention and control arms, including 765 mother-infant pairs (PROMISE-EBF trial, 200608, ClinicalTrials.gov no. NCT00397150). Intervention clusters received the promotion of EBF by peer counselors in addition to standard care. Breastfeeding and growth outcomes were compared according to wealth quintiles and intervention/control arms. Socioeconomic inequality in breastfeeding and growth outcomes were measured using the concentration index 12 and 24 weeks postpartum. We used the decomposition of the concentration index to identify factors contributing to growth inequality at 24 weeks. EBF was significantly concentrated among the poorest in the intervention group at 24 weeks postpartum, concentration index -0.060. The control group showed a concentration of breastfeeding among the richest part of the population, although not statistically significant. Stunting, wasting, and underweight were similarly significantly concentrated among the poorest in the intervention group and the total population at 24 weeks, but showing non-significant concentrations for the control group. This study shows that EBF can be successfully promoted among the poor. In addition, socioeconomic inequality in growth outcomes starts early in infancy, but the breastfeeding intervention was not strong enough to counteract this influence.

Degree of compliance with the ten steps of the Breastfeeding Friendly Primary Care Initiative and its association with the prevalence of exclusive breastfeeding.

PubMed

Rito, Rosane Valéria Viana Fonseca; Oliveira, Maria Inês Couto de; Brito, Alexandre dos Santos

2013-01-01

To analyze the association between the degree of compliance with the ten steps of the Breastfeeding-Friendly Primary Care Initiative (BFPCI) and the prevalence of exclusive breastfeeding (EBF) in infants younger than six months in the city of Rio de Janeiro. This was a cross-sectional study conducted in a representative sample of 56 primary health care units of this municipality. The assessment of compliance with the ten steps of the BFPCI was carried out by interviewing health care professionals, pregnant women, and mothers; the generated performance scores were classified into tertiles. To obtain the outcome, i.e., the EBF, a data collection questionnaire was applied to mothers of children younger than six months who were followed up at these units in November of 2007. Prevalence ratios were obtained for the EBF using Poisson regression with robust variance. The prevalence of EBF was 47.6%. In the multivariate analysis, the upper tertile of performance showed a 34% higher prevalence of EBF (PR=1.34, 95% CI: 1.24 to 1.44) and the second tertile was 17% higher (PR=1.17, 95% CI: 1.08 to 1.27) than the first tertile. Mothers who did not work outside home had a 75% higher prevalence of EBF (PR=1.75, 95% CI: 1.53 to 2.01); assistance in a basic health unit, as opposed to a family health unit, implied a 10% higher prevalence (PR=1.10, 95% CI: 1.03 to 1.19). The prevalence of EBF decreased 1% for each day of the infant's life (PR=0.993, 95% CI: 0.992 to 0.993). Given the contribution of BFPCI to the practice of EBF, a greater investment in the expansion and sustainability of this initiative is recommended, as well as its association with other strategies to promote, protect, and support breastfeeding. Copyright © 2013 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.

A relationship between a level of hemoglobin after delivery and exclusive breastfeeding initiation at a baby friendly hospital in Japan.

PubMed

Horie, Saki; Nomura, Kyoko; Takenoshita, Shinichi; Nakagawa, Junko; Kido, Michiko; Sugimoto, Mitsuhiro

2017-04-20

The recent National Nutrition Survey of 2013 demonstrated that 16.7% of women in childbearing age are underweight, and 5.0-10.0% of these women manifested a Hemoglobin (Hb) level less than 11.0 g/dl. The purpose of this study was to investigate if such maternal nutritional status affects success of exclusive breastfeeding (EBF) practice. This cross-sectional study investigated 1532 dyads of mothers and infants with full-term singleton pregnancies delivered during 2011 at a perinatal center in Tokyo. Outcome is EBF initiation defined as the successful practice at discharge and 1 month after discharge. A logistic regression model was applied to investigate the impact of Hb levels (<9.0, 9.0-10.9, and ≥11.0 g/dl) measured within 2-3 days after delivery on successful EBF initiation adjusting for covariates including bleeding at delivery. Mean age was 34 years, 23.0% were underweight and 63.0% were nulliparous. The success rate for EBF initiation at discharge and at 1 month after discharge was 72.7 and 63.0% for a Hb level <9.0 g/dl, 81.9 and 68.9% for a Hb level of 9.0-10.9 g/dl, and 85.7 and 75.9% for a Hb level ≥11.0 g/dl, respectively. A logistic regression model showed that risk factors of unsuccessful EBF practice at discharge and 1 month after discharge included lower level Hb categories (P < 0.001 and P < 0.001), postpartum hemorrhage > 500 ml (P = 0.089 and P = 0.011), maternal age (P < 0.001 and P < 0.001), nulliparity (P < 0.0001 and P < 0.001), pregnancy-induced hypertension (P = 0.002 and P = 0.012), gestational week (P = 0.006 and P = 0.002), Low Birth Weight (LBW) (P < 0.001 and P < 0.001), and immediate separation (P < 0.001 and P = 0.020). After adjusting for the covariates, compared with a Hb level ≥11.0 g/dl, a Hb level <9.0 g/dl was significantly associated with unsuccessful EBF initiation at discharge [odds ratio (OR): 2.15; 95% confidence interval (CI): 1.37-3.39] and at 1 month after discharge (OR: 1.63; 95% CI: 1.10-2.42), and a Hb level of 9.0-10.9 g/dl also was significant at 1 month after discharge (OR: 1.35; 95% CI: 1.04-1.75). Pre-pregnancy underweight was not associated with success of EBF practice both at hospital discharge and 1 month after discharge. Maternal severe anemia after delivery was associated with the risk of unsuccessful initiation of EBF even after adjusting for bleeding at delivery, suggesting the importance of dietary management especially in the later trimester.

Reasons for non-exclusive breast-feeding in the first 6 months.

PubMed

Zielinska, Monika A; Hamulka, Jadwiga

2018-03-01

Maternal sociodemographic, delivery- and infant-related factors as well as hospital practice are relevant for breast-feeding practice. The aim of this study was to identify the sociodemographic and delivery-related factors that may affect exclusive breast-feeding (EBF) of infants aged 0-6 months in Poland. A total of 446 mothers (18-42 years old) of infants aged 0-6 months were interviewed using the computer-assisted Web interview method. The questionnaire collected information about maternal sociodemographic situation and anthropometrics, delivery-related factors, and infant feeding-related factors. Data were analyzed using the chi-squared test and Mann-Whitney U-test. Predictors of non-exclusive breast-feeding (N-EBF) in the first 6 months of life were assessed on multivariate logistic regression. A total of 43% of mothers did not breast-feed exclusively (n = 191; N-EBF group) and 57% did breast-feed exclusively during the study period (n = 255; EBF group). After adjustment for other potential risk factors, the highest risk factors for N-EBF were maternal age <20 years (OR, 6.12; P ≤ 0.01), and inadequate breast-feeding knowledge (OR, 3.43; P ≤ 0.01), whereas the lowest risk was associated with pre-pregnancy intention to breast-feed (OR, 0.35; P ≤ 0.01), very good knowledge about breast-feeding (OR, 0.45; P ≤ 0.001) and maternal age 26-30 years (OR, 0.48; P ≤ 0.001). In a multivariate model, maternal education, employment status and preterm delivery were no longer statistically significant. Breast-feeding practice is influenced by a variety of factors, including sociodemographic and psychosocial conditions, maternal obesity and mode of delivery. Further work is needed to establish the role of education and prophylactic programs in modifying the aforementioned risk factors. © 2017 Japan Pediatric Society.

Exclusive Breastfeeding and Cognition, Executive Function, and Behavioural Disorders in Primary School-Aged Children in Rural South Africa: A Cohort Analysis.

PubMed

Rochat, Tamsen J; Houle, Brian; Stein, Alan; Coovadia, Hoosen; Coutsoudis, Anna; Desmond, Chris; Newell, Marie-Louise; Bland, Ruth M

2016-06-01

Exclusive breastfeeding (EBF) is associated with early child health; its longer-term benefits for child development remain inconclusive. We examine the associations between EBF, HIV exposure, and other maternal/child factors and the cognitive and emotional-behavioural development of children aged 7-11 y. The Vertical Transmission Study (VTS) supported EBF in HIV-positive and HIV-negative women; between 2012 and 2014, HIV-negative VTS children (332 HIV exposed, 574 HIV unexposed) were assessed in terms of cognition (Kaufman Assessment Battery for Children Second Edition [KABC-II]), executive function (Developmental Neuropsychological Assessment Second Edition [NEPSY-II]), and emotional-behavioural functioning (parent-reported Child Behaviour Checklist, [CBCL]). We developed population means by combining the VTS sample with 629 same-aged HIV-negative children from the local demographic platform. For each outcome, we split the VTS sample into scores above or at/below each population mean and modelled each outcome using logistic regression analyses, overall and stratified by child sex. There was no demonstrated effect of EBF on overall cognitive functioning. EBF was associated with fewer conduct disorders overall (adjusted odds ratio [aOR] 0.44 [95% CI 0.3-0.7], p ≤ 0.01), and there was weak evidence of better cognition in boys who had been exclusively breastfed for 2-5 mo versus ≤1 mo (Learning subscale aOR 2.07 [95% CI 1.0-4.3], p = 0.05). Other factors associated with better child cognition were higher maternal cognitive ability (aOR 1.43 [95% CI 1.1-1.9], p = 0.02, Sequential; aOR 1.74 [95% CI 1.3-2.4], p < 0.001, Planning subscales) and crèche attendance (aOR 1.96 [95% CI 1.1-3.5], p = 0.02, Sequential subscale). Factors positively associated with executive function were home stimulation (aOR 1.36 [95% CI 1.0-1.8], p = 0.04, Auditory Attention; aOR 1.35 [95% CI 1.0-1.8], p = 0.05, Response Set) and crèche (aOR 1.74 [95% CI 1.0-3.0], p = 0.05, Animal Sorting). Maternal mental health problems and parenting stress were associated with increased emotional-behavioural problems on the total CBCL (aOR 2.44 [95% CI 1.3-4.6], p = 0.01; aOR 7.04 [95% CI 4.2-11.9], p < 0.001, respectively). Maternal HIV status was not associated with any outcomes in the overall cohort. Limitations include the nonrandomised study design and lack of maternal mental health assessment at the child's birth. EBF was associated with fewer than average conduct disorders and weakly associated with improved cognitive development in boys. Efforts to improve stimulation at home, reduce maternal stress, and enable crèche attendance are likely to improve executive function and emotional-behavioural development of children.

Groundwater productivity potential mapping using evidential belief function.

PubMed

Park, Inhye; Kim, Yongsung; Lee, Saro

2014-09-01

The evidential belief function (EBF) model was applied and validated for analysis of groundwater-productivity potential (GPP) in Boryeong and Pohang cities, agriculture region in Korea using geographic information systems (GIS). Data about related factors, including topography, lineament, geology, forest, soil, and groundwater data were collected and input into a spatial database. Additionally, in the Boryeong area, specific capacity (SPC) data not lower than 4.55 m3 /d/m were collected, corresponding to 300 m3 /d yield from 72 well locations. In the Pohang area, SPC data of ≥ 6.25 m3 /d/m were collected, corresponding to a yield of 500 m3 /d from 44 well locations. By using the constructed spatial database, 19 factors related to groundwater productivity were extracted. The relationships between the well locations and the factors were identified and quantified by using the EBF model. Four relationships were calculated: belief (Bel), disbelief (Dis), uncertainty (Unc), and plausibility (Pls). The relationships were used as factor ratings in the overlay analysis to create GPP indices and maps. The resulting GPP maps showed 83.41% and 77.53% accuracy in Boryeong and Pohang areas, respectively. The EBF model was found to be more effective in terms of prediction accuracy. © 2014, National Ground Water Association.

Impact of counselling on exclusive breast-feeding practices in a poor urban setting in Kenya: a randomized controlled trial.

PubMed

Ochola, Sophie A; Labadarios, Demetre; Nduati, Ruth W

2013-10-01

To determine the impact of facility-based semi-intensive and home-based intensive counselling in improving exclusive breast-feeding (EBF) in a low-resource urban setting in Kenya. A cluster randomized controlled trial in which nine villages were assigned on a 1:1:1 ratio, by computer, to two intervention groups and a control group. The home-based intensive counselling group (HBICG) received seven counselling sessions at home by trained peers, one prenatally and six postnatally. The facility-based semi-intensive counselling group (FBSICG) received only one counselling session prenatally. The control group (CG) received no counselling from the research team. Information on infant feeding practices was collected monthly for 6 months after delivery. The data-gathering team was blinded to the intervention allocation. The outcome was EBF prevalence at 6 months. Kibera slum, Nairobi. A total of 360 HIV-negative women, 34-36 weeks pregnant, were selected from an antenatal clinic in Kibera; 120 per study group. Of the 360 women enrolled, 265 completed the study and were included in the analysis (CG n 89; FBSICG n 87; HBICG n 89). Analysis was by intention to treat. The prevalence of EBF at 6 months was 23.6% in HBICG, 9.2% in FBSICG and 5.6% in CG. HBICG mothers had four times increased likelihood to practise EBF compared with those in the CG (adjusted relative risk = 4.01; 95% CI 2.30, 7.01; P=0.001). There was no significant difference between EBF rates in FBSICG and CG. EBF can be promoted in low socio-economic conditions using home-based intensive counselling. One session of facility-based counselling is not sufficient to sustain EBF.

Exclusive breast-feeding promotion among HIV-infected women in South Africa: an Information-Motivation-Behavioural Skills model-based pilot intervention.

PubMed

Tuthill, Emily L; Butler, Lisa M; Pellowski, Jennifer A; McGrath, Jacqueline M; Cusson, Regina M; Gable, Robert K; Fisher, Jeffrey D

2017-06-01

Exclusive breast-feeding (EBF) provides optimal nutrition for infants and mothers. The practice of EBF while adhering to antiretroviral medication decreases the risk of mother-to-child transmission of HIV from approximately 25 % to less than 5 %. Thus the WHO recommends EBF for the first 6 months among HIV-infected women living in resource-limited settings; however, EBF rates remain low. In the present study our aim was to design and implement a pilot intervention promoting EBF among HIV-infected women. The Information-Motivation-Behavioural Skills (IMB) model was applied in a brief motivational interviewing counselling session that was tested in a small randomized controlled trial. Pietermaritzburg, South Africa, at two comparable rural public health service clinics. Sixty-eight HIV-infected women in their third trimester were enrolled and completed baseline interviews between June and August 2014. Those randomized to the intervention arm received the IMB-based pilot intervention directly following baseline interviews. Follow-up interviews occurred at 6 weeks postpartum. While not significantly different between trial arms, high rates of intention and practice of EBF at 6-week follow-up were reported. Findings showed high levels of self-efficacy being significantly predictive of breast-feeding initiation and duration regardless of intervention arm. Future research must account for breast-feeding self-efficacy on sustaining breast-feeding behaviour and leverage strategies to enhance self-efficacy in supportive interventions. Supporting breast-feeding behaviour through programmes that include both individual-level and multi-systems components targeting the role of health-care providers, family and community may create environments that value and support EBF behaviour.

Local blood flow in peripheral nerves and their ganglia: Resurrecting key ideas around its measurement and significance.

PubMed

Zochodne, Douglas W

2018-06-01

Over 3 decades ago, seminal work by Phillip Low and colleagues established exquisite physiology around the measurement of nerve blood flow (NBF). Although not widely explored recently, its connection to the clinic has awaited human methodology. While human studies have not achieved a convincing level of rigour, newer imaging technologies are offering early information. The peripheral nerve trunk has parallel blood flow compartments that include epineurial flow dominated by arteriovenous shunts and downstream endoneurial blood flow (EBF). NBF and EBF have lower values than central nervous system blood flow, lack autoregulation yet have sympathetic and peptidergic neurovascular control. Contrary to expectation, injury to nerves is often associated with rises in NBF rather than ischemia, a finding of biological interest corroborated by human studies. Despite its potential importance, quantitative human measurements of EBF and NBF are not yet available. However, with development, careful NBF analysis may present new insights into nerve disorders. Muscle Nerve 57: 884-895, 2018. © 2017 Wiley Periodicals, Inc.

Factors are not the same for risk of stopping exclusive breast-feeding and introducing different types of liquids and solids in HIV-affected communities in Ghana.

PubMed

Marquis, Grace S; Lartey, Anna; Perez-Escamilla, Rafael; Mazur, Robert E; Brakohiapa, Lucy; Birks, Katherine A

2016-07-01

Exclusive breast-feeding (EBF) for 6 months supports optimal infant growth, health and development. This paper examined whether maternal HIV status was associated with EBF and other infant feeding practices. Pregnant women were enrolled after HIV counselling, and their babies were followed up for up to 1 year. Data on household socio-economics and demographics, maternal characteristics and infants' daily diet were available for 482 infants and their mothers (150 HIV-positive (HIV-P), 170 HIV-negative (HIV-N) and 162 HIV-unknown (HIV-U)). Survival analyses estimated median EBF duration and time to introduction of liquids and foods; hazards ratios (HR) used data from 1-365 and 1-183 d, adjusting for covariates. Logistic regression estimated the probability of EBF for 6 months. Being HIV-P was associated with a shorter EBF duration (139 d) compared with HIV-N (163 d) and HIV-U (165 d) (P=0·004). Compared with HIV-N, being HIV-P was associated with about a 40 % higher risk of stopping EBF at any time point (HR 1·39; 95 % CI 1·06, 1·84; P=0·018) and less than half as likely to complete 6 months of EBF (adjusted OR 0·42; 95 % CI 0·22, 0·81; P=0·01). Being HIV-P tended to be or was associated with a higher risk of introducing non-milk liquids (HR 1·34; 95 % CI 0·98, 1·83; P=0·068), animal milks (HR 2·37; 95 % CI 1·32, 4·24; P=0·004) and solids (HR 1·56; 95 % CI 1·10, 2·22; P=0·011) during the first 6 months. Weight-for-age Z-score was associated with EBF and introducing formula. Different factors (ethnicity, food insecurity, HIV testing strategy) were associated with the various feeding behaviours, suggesting that diverse interventions are needed to promote optimal infant feeding.

Flowmeter and Ground Penetrating Radar: comparison between hydrogeological and geophysical methods

NASA Astrophysics Data System (ADS)

Villa, A.; Basirico', S.; Arato, A.; Crosta, G. B.; Frattini, P.; Godio, A.

2012-04-01

A comparison between saturated hydraulic conductivity calculated with Electromagnetic Borehole Flowmeter (EBF) and water content obtained by Ground Penetrating Radar (GPR) Zero Offset Profile (ZOP) is presented. EBF technique permits to obtain permeability profiles along one borehole in the saturated zone by using the Moltz (1993) method. The analysis of ZOP data provides information about the water content (Topp, 1980) in the section between two adjacent boreholes. Water content profiles in the saturated zone can be related to the porosity of the medium which, together with the permeability from EBF measurements, is fundamental for any hydrogeological characterization. These two methods have been applied to three different test-sites located in the Northern Italy. A first site regards a complex aquifer, characterized by a chaotic sequence of gypsum-marls. The other two sites are characterized by an alternation of sandy and silty-sandy layers. For each site, we adopted the EBF along screened boreholes with 0.25 m spacing, under ambient and stressed conditions. The cross-hole georadar survey was performed within the saturated zone by using 100 Hz borehole antennas with 0.25 m spacing. The results from the analysis of EBF and ZOP profiles show a general positive correlation between permeability and water content and porosity. This is reasonable for granular soils where the permeability is controlled by the pore space available for water flow, i.e., the effective porosity. For this soils, where EBF permeability and ZOP water-content profiles are in good agreement, the volume between the boreholes can be supposed to be homogeneous. On the other hand, a poor correlation suggests the presence of heterogeneity between the boreholes, which can be observed because the two techniques involve different volumes of soil: the EBF permeability refers to a portion of volume just around the borehole while the ZOP investigates the entire volume between the two boreholes. The poor correlation could be enhanced when enlarging the borehole separation, because the difference in the involved volume between the two techniques increases. Finally, the degree of correlation between the EBF permeability profile and the ZOP water content profile can indicate how much the volume investigated by EBF is effectively representative of the entire volume between the boreholes. Molz, F.J. and S.C. Young, 1993. Development and Application of Borehole Flowmeters for Environmental Assessment, The Log Analyst, 13-23. Topp G.C., J.L. Davis and A.P. Annan, 1980. Electromagnetic determination of soil water content: measurements in coaxial transmission lines, Water Resources Research, 16, 574-582.

HPV status-independent association of alcohol and tobacco exposure or prior radiation therapy with promoter methylation of FUSSEL18, EBF3, IRX1, and SEPT9, but not SLC5A8, in head and neck squamous cell carcinomas.

PubMed

Bennett, Kristi L; Lee, Walter; Lamarre, Eric; Zhang, Xiatong; Seth, Rahul; Scharpf, Joseph; Hunt, Jennifer; Eng, Charis

2010-04-01

Head and neck squamous cell carcinoma (HNSCC) is an aggressive malignancy with more than half a million people being diagnosed with the disease annually. Within the last 2 decades, the human papillomavirus (HPV) has been found to be associated with this malignancy. More recently, HPV-infected HNSCC has been found to exhibit higher levels of global DNA methylation. In a recent study, we identified five tumor suppressive genes (IRX1, EBF3, SLC5A8, SEPT9, and FUSSEL18) as frequently methylated in HNSCC biopsies using a global methylation analysis via restriction landmark genomic scanning. In this study, we verify these genes as valid methylation markers in two separate sets of HNSCC specimens. By using the available clinical information linked to the patient specimens, we found a strong association between promoter methylation of FUSSEL18, IRX1, and EBF3 and prior radiation therapy (P < 0.0001) irrespective of HPV status. Also, promoter methylation of FUSSEL18 and SEPTIN9 was found to correlate significantly with exposure to alcohol and tobacco (P = 0.021). Importantly, in this study, we preliminarily show a trend between HPV16 positivity and specific target gene hypermethylation of IRX1, EBF3, SLC5A8, and SEPT9. If replicated in a larger study, the HPV status may be a patient selection biomarker when determining the most efficacious treatment modality for these different subsets of patients (e.g., inclusion or exclusion of epigenetic therapies). Equally notable and independent of HPV status, hypermethylation of the promoters of a subset of these genes in recurrences especially in the setting of prior radiation or in the setting of alcohol and tobacco use might help guide adjunctive inclusion or exclusion or epigenetic therapy.

Exclusive Breastfeeding and Cognition, Executive Function, and Behavioural Disorders in Primary School-Aged Children in Rural South Africa: A Cohort Analysis

PubMed Central

Rochat, Tamsen J.; Houle, Brian; Stein, Alan; Coovadia, Hoosen; Coutsoudis, Anna; Desmond, Chris; Newell, Marie-Louise; Bland, Ruth M.

2016-01-01

Background Exclusive breastfeeding (EBF) is associated with early child health; its longer-term benefits for child development remain inconclusive. We examine the associations between EBF, HIV exposure, and other maternal/child factors and the cognitive and emotional-behavioural development of children aged 7–11 y. Methods and Findings The Vertical Transmission Study (VTS) supported EBF in HIV-positive and HIV-negative women; between 2012 and 2014, HIV-negative VTS children (332 HIV exposed, 574 HIV unexposed) were assessed in terms of cognition (Kaufman Assessment Battery for Children Second Edition [KABC-II]), executive function (Developmental Neuropsychological Assessment Second Edition [NEPSY-II]), and emotional-behavioural functioning (parent-reported Child Behaviour Checklist, [CBCL]). We developed population means by combining the VTS sample with 629 same-aged HIV-negative children from the local demographic platform. For each outcome, we split the VTS sample into scores above or at/below each population mean and modelled each outcome using logistic regression analyses, overall and stratified by child sex. There was no demonstrated effect of EBF on overall cognitive functioning. EBF was associated with fewer conduct disorders overall (adjusted odds ratio [aOR] 0.44 [95% CI 0.3–0.7], p ≤ 0.01), and there was weak evidence of better cognition in boys who had been exclusively breastfed for 2–5 mo versus ≤1 mo (Learning subscale aOR 2.07 [95% CI 1.0–4.3], p = 0.05). Other factors associated with better child cognition were higher maternal cognitive ability (aOR 1.43 [95% CI 1.1–1.9], p = 0.02, Sequential; aOR 1.74 [95% CI 1.3–2.4], p < 0.001, Planning subscales) and crèche attendance (aOR 1.96 [95% CI 1.1–3.5], p = 0.02, Sequential subscale). Factors positively associated with executive function were home stimulation (aOR 1.36 [95% CI 1.0–1.8], p = 0.04, Auditory Attention; aOR 1.35 [95% CI 1.0–1.8], p = 0.05, Response Set) and crèche (aOR 1.74 [95% CI 1.0–3.0], p = 0.05, Animal Sorting). Maternal mental health problems and parenting stress were associated with increased emotional-behavioural problems on the total CBCL (aOR 2.44 [95% CI 1.3–4.6], p = 0.01; aOR 7.04 [95% CI 4.2–11.9], p < 0.001, respectively). Maternal HIV status was not associated with any outcomes in the overall cohort. Limitations include the nonrandomised study design and lack of maternal mental health assessment at the child’s birth. Conclusions EBF was associated with fewer than average conduct disorders and weakly associated with improved cognitive development in boys. Efforts to improve stimulation at home, reduce maternal stress, and enable crèche attendance are likely to improve executive function and emotional-behavioural development of children. PMID:27328132

Fitness, obesity and risk of heat illness among army trainees.

PubMed

Bedno, S A; Urban, N; Boivin, M R; Cowan, D N

2014-09-01

Exertional heat illness (EHI) affects military personnel, athletes and occupational groups such as agricultural workers, despite knowledge of preventive measures. To evaluate EHI diagnoses during US Army basic training and its associations with fitness and body fat on entering military service. From February 2005 to September 2006, US Army recruits at six different military entrance stations took a pre-accession fitness test, including a 5-min step test scored as pass or fail. Subsequent EHI incidence and incidence rate ratios were analysed with reference to subjects' fitness (step test performance) and whether they met (weight qualified [WQ]) or exceeded body fat (EBF) standards. Among the 8621 WQ and 834 EBF male subjects, there were 67 incidents of EHI within 180 days of entering military service. Among WQ subjects, step test failure was significantly associated with EHI (odds ratio [OR] 2.00, 95% confidence interval [CI] 1.13, 3.53). For those passing the step test, the risk of EHI was significantly higher in EBF than in WQ subjects (OR 3.98, 95% CI 2.17, 7.29). Expected ORs for the joint effects of step test failure and EBF classification under additive and multiplicative models were 4.98 and 7.96, respectively. There were too few women to evaluate their data in detail. This study demonstrated that fitness and body fat are independently associated with incident EHI, and the effect of both was substantially higher. Those with low fitness levels and/or obesity should be evaluated further before engaging in intense physical activity, especially in warmer months. Published by Oxford University Press on behalf of the Society of Occupational Medicine 2014.This work is written by (a) US Government employee(s) and is in the public domain in the US.

Effect of feeding pattern on infant illness in Chinese cities.

PubMed

Cai, Li; Yu, Pan; Zhang, Yumei; Yang, Xiaoguang; Li, Wenjun; Wang, Peiyu

2016-05-01

To investigate the effect of different feeding patterns on the occurrence of diseases among infants. Data on socio-economic status, feeding patterns before 6 months (exclusive breast-feeding (EBF); mixed feeding with breast milk and formula (MBF); exclusive formula-feeding (EFF)) and illness of infants were collected via face-to-face interviews. The proportions of infants who had ever been ill or hospitalized and their potential influence factors were investigated. Eight large cities in China. Infants (n 1654) aged 0-11·9 months were recruited from hospitals. For infants aged 0-2·9 months, the percentage who had been ill was 19·2%, 24·1% and 26·3% among the EBF, MBF and EFF groups, respectively. For those aged 3-5·9 and 6-11·9 months, the corresponding percentages were 41·6%, 45·6% and 51·0%, and 67·0%, 73·4% and 67·7%. Respiratory disease was the most common reported illness and cause of hospitalization. The risks of having (total) illness, diarrhoea and respiratory disease increased significantly with age, but not allergic disease. Compared with EBF, MBF and EFF infants had significantly higher risks of having illnesses except for allergic disease, and feeding patterns were not related to hospitalization. Low birth weight, middle family income and low level of mother's education also increased the risk of illness. A protective effect of EBF against total illness in urban Chinese infants was found. An increasing trend with age was observed among the percentages of infants who had been ill or had diarrhoea or respiratory disease, but not allergic disease.

Calculating Exclusive Breastfeeding Rates: Comparing Dietary "24-Hour Recall" with Recall "Since Birth" Methods.

PubMed

Abdel-Hady, Doaa M; El-Gilany, Abdel-Hady

2016-12-01

Calculating exclusive breastfeeding (EBF) rates based on the previous-day recall has been recommended by the World Health Organization to avoid the recall bias but it also may not accurately reflect the feeding pattern since birth and leads to overestimate of the proportion of exclusively breastfed infants. The objective of this study was to compare the (EBF) rates calculated by the 24-hour recall and since birth recall and their association with different sociodemographic and maternal data. Prospective descriptive study in Mansoura District including 1,102 mother-infant dyad attending primary healthcare centers for vaccination. One thousand ninety-one and 1,029 were followed up at 4 and 6 months during a period from January to October 2015. Sociodemographic data, maternal, antenatal, birth, and some infant related data were collected through interview. Questions about EBF using the 24-hour recall and since birth recall definitions were asked. This study shows consistent difference in breastfeeding pattern reported by 24-hour recall with recall since birth at all age intervals. At the age of 6 months 13.6% of infants were EBF as reported by 24-hour recall method versus 5.2% for recall since birth method. Different factors were associated with EBF practice reported using these different methods. The two recall methods describe the reality in different and incomplete ways. It is better to measure and report EBF rated using both methods so as to give a full picture of breastfeeding practice. And it is very important to distinguish between both methods and not to be used interchangeably with each other.

Effect of Breastfeeding Promotion on Early Childhood Caries and Breastfeeding Duration among 5 Year Old Children in Eastern Uganda: A Cluster Randomized Trial.

PubMed

Birungi, Nancy; Fadnes, Lars T; Okullo, Isaac; Kasangaki, Arabat; Nankabirwa, Victoria; Ndeezi, Grace; Tumwine, James K; Tylleskär, Thorkild; Lie, Stein Atle; Åstrøm, Anne Nordrehaug

2015-01-01

Although several studies have shown short term health benefits of exclusive breastfeeding (EBF), its long term consequences have not been studied extensively in low-income contexts. This study assessed the impact of an EBF promotion initiative for 6 months on early childhood caries (ECC) and breastfeeding duration in children aged 5 years in Mbale, Eastern Uganda. Participants were recruited from the Ugandan site of the PROMISE- EBF cluster randomised trial (ClinicalTrials.gov no: NCT00397150). A total of 765 pregnant women from 24 clusters were included in the ratio 1:1 to receive peer counselled promotion of EBF as the intervention or standard of care. At the 5 year follow-up, ECC was recorded under field conditions using the World Health Organization's decayed missing filled tooth (dmft) index. Adjusted negative binomial and linear regression were used in the analysis. Mean breastfeeding duration in the intervention and control groups (n=417) were 21.8 (CI 20.7-22.9) and 21.3(CI 20.7-21.9) months, respectively. The mean dmft was 1.5 (standard deviation [SD] 2.9) and 1.7 (SD 2.9) in the intervention and control groups, respectively. Corresponding prevalence estimates of ECC were 38% and 41%. Negative binomial regression analysis adjusted for cluster effects and loss-to-follow-up by inverse probability weights (IPW) showed an incidence-rate ratio (IRR) of 0.91 (95% CI 0.65-1.2). Comparing the effect of the trial arm on breastfeeding duration showed a difference in months of 0.48 (-0.72 to 1.7). PROMISE EBF trial did not impact on early childhood caries or breastfeeding duration at 5 years of age. This study contributes to the body of evidence that promotion of exclusive breastfeeding does not raise oral health concerns. However, the high burden of caries calls for efforts to improve the oral health condition in this setting. ClinicalTrials.gov NCT00397150.

Monte Carlo simulation of MOSFET dosimeter for electron backscatter using the GEANT4 code.

PubMed

Chow, James C L; Leung, Michael K K

2008-06-01

The aim of this study is to investigate the influence of the body of the metal-oxide-semiconductor field effect transistor (MOSFET) dosimeter in measuring the electron backscatter from lead. The electron backscatter factor (EBF), which is defined as the ratio of dose at the tissue-lead interface to the dose at the same point without the presence of backscatter, was calculated by the Monte Carlo simulation using the GEANT4 code. Electron beams with energies of 4, 6, 9, and 12 MeV were used in the simulation. It was found that in the presence of the MOSFET body, the EBFs were underestimated by about 2%-0.9% for electron beam energies of 4-12 MeV, respectively. The trend of the decrease of EBF with an increase of electron energy can be explained by the small MOSFET dosimeter, mainly made of epoxy and silicon, not only attenuated the electron fluence of the electron beam from upstream, but also the electron backscatter generated by the lead underneath the dosimeter. However, this variation of the EBF underestimation is within the same order of the statistical uncertainties as the Monte Carlo simulations, which ranged from 1.3% to 0.8% for the electron energies of 4-12 MeV, due to the small dosimetric volume. Such small EBF deviation is therefore insignificant when the uncertainty of the Monte Carlo simulation is taken into account. Corresponding measurements were carried out and uncertainties compared to Monte Carlo results were within +/- 2%. Spectra of energy deposited by the backscattered electrons in dosimetric volumes with and without the lead and MOSFET were determined by Monte Carlo simulations. It was found that in both cases, when the MOSFET body is either present or absent in the simulation, deviations of electron energy spectra with and without the lead decrease with an increase of the electron beam energy. Moreover, the softer spectrum of the backscattered electron when lead is present can result in a reduction of the MOSFET response due to stronger recombination in the SiO2 gate. It is concluded that the MOSFET dosimeter performed well for measuring the electron backscatter from lead using electron beams. The uncertainty of EBF determined by comparing the results of Monte Carlo simulations and measurements is well within the accuracy of the MOSFET dosimeter (< +/- 4.2%) provided by the manufacturer.

Financing the World Health Organisation: global importance of extrabudgetary funds.

PubMed

Vaughan, J P; Mogedal, S; Kruse, S; Lee, K; Walt, G; de Wilde, K

1996-03-01

From 1948, when WHO was established, the Organisation has relied on the assessed contributions of its member states for its regular budget. However, since the early 1980s the WHO World Health Assembly has had a policy of zero real growth for the regular budget and has had to rely increasingly, therefore, on attracting additional voluntary contributions, called extrabudgetary funds (EBFs). Between 1984-85 and 1992-93 the real value of the EBFs apparently increased by more than 60% and in the 1990-91 biennium expenditure of extrabudgetary funds exceeded the regular budget for the first time. All WHO programmes, except the Assembly and the Executive Board, receive some EBFs. However, three cosponsored and six large regular programmes account for about 70% of these EBFs, mainly for vertically managed programmes in the areas of disease control, health promotion and human reproduction. Eighty percent of all EBFs received by WHO for assisted activities have been contributed by donor governments, with the top 10 countries (in Europe, North America and Japan) contributing about 90% of this total, whereas the UN funds and the World Bank have donated only about 6% of the total to date. By contrast, about 70% of the regular budget expenditure has been for organisational expenses and for the support of programmes in the area of health systems. Despite the fact that the more successful programmes are heavily reliant on EBFs, there are strong indications that donors, particularly donor governments, are reluctant to maintain the current level of funding without major reforms in the leadership and management of the Organisation. This has major implications for WHO's international role as the leading UN specialised agency for health.

Bamboo Expansion Alters Ecosystem NPP and N Cycling of Evergreen Broad-leaved Forest in Subtropical China

NASA Astrophysics Data System (ADS)

Lu, H.; Song, Q. N.; Wang, W.

2016-12-01

Background and Aims The bamboo (Phyllostachys pubescens) expansion into adjacent forests is a widespread phenomenon in subtropical region, and it has imposed great effects on the species compositions and community structures of cloned ecosystems. This shift in dominant plant life form, from trees to bamboos, may be accompanied by changes in the productivity, standing accumulation of biomass and nutrients and biogeochemical cycles. Methods We compared the net primary production (NPP) and major pools and fluxes of nitrogen (N) in bamboo-dominant forest (BDF) and neighboring secondary evergreen broadleaved forest (EBF) in South China using the space-for-time substitution method. Results The mean annual NPP of BDF was 30.0 t ha-1 a-1, which was 51.5 % greater than that of the EBF (19.8 t ha-1 a-1), with fine root contributed more than 8.2 kg ha-1. The plant N pool for BDF was 37.5% larger than that of the EBF, because of higher N content in P. pubescens tissues relative to that in trees, whereas the soil inorganic N pool significantly decreased in the EBF by 31.2 % compared with that in the BDF. Additionally, the ratio of N return to N uptake was 0.69 in the BDF and 0.88 in the EBF because of the lower litter N return of the BDF compared with that of the EBF. Conclusion These results indicated that the expansion of P. pubescens significantly increased the NPP and plant N accumulation but reduced the soil N available pool and slowed the N cycling rate, which could lead to soil degradation. These findings have great additional information for the assessment of P. pubescens expansion, and enrich our understanding of bamboo expansion into neighboring forests in subtropical China.

A study of the variable impedance surface concept as a means for reducing noise from jet interaction with deployed lift-augmenting flaps

NASA Technical Reports Server (NTRS)

Hayden, R. E.; Kadman, Y.; Chanaud, R. C.

1972-01-01

The feasibility of quieting the externally-blown-flap (EBF) noise sources which are due to interaction of jet exhaust flow with deployed flaps was demonstrated on a 1/15-scale 3-flap EBF model. Sound field characteristics were measured and noise reduction fundamentals were reviewed in terms of source models. Test of the 1/15-scale model showed broadband noise reductions of up to 20 dB resulting from combination of variable impedance flap treatment and mesh grids placed in the jet flow upstream of the flaps. Steady-state lift, drag, and pitching moment were measured with and without noise reduction treatment.

Effectiveness of home-based nutritional counselling and support on exclusive breastfeeding in urban poor settings in Nairobi: a cluster randomized controlled trial.

PubMed

Kimani-Murage, Elizabeth W; Griffiths, Paula L; Wekesah, Frederick Murunga; Wanjohi, Milka; Muhia, Nelson; Muriuki, Peter; Egondi, Thaddaeus; Kyobutungi, Catherine; Ezeh, Alex C; McGarvey, Stephen T; Musoke, Rachel N; Norris, Shane A; Madise, Nyovani J

2017-12-19

Exclusive breastfeeding (EBF) improves infant health and survival. We tested the effectiveness of a home-based intervention using Community Health Workers (CHWs) on EBF for six months in urban poor settings in Kenya. We conducted a cluster-randomized controlled trial in Korogocho and Viwandani slums in Nairobi. We recruited pregnant women and followed them until the infant's first birthday. Fourteen community clusters were randomized to intervention or control arm. The intervention arm received home-based nutritional counselling during scheduled visits by CHWs trained to provide specific maternal infant and young child nutrition (MIYCN) messages and standard care. The control arm was visited by CHWs who were not trained in MIYCN and they provided standard care (which included aspects of ante-natal and post-natal care, family planning, water, sanitation and hygiene, delivery with skilled attendance, immunization and community nutrition). CHWs in both groups distributed similar information materials on MIYCN. Differences in EBF by intervention status were tested using chi square and logistic regression, employing intention-to-treat analysis. A total of 1110 mother-child pairs were involved, about half in each arm. At baseline, demographic and socioeconomic factors were similar between the two arms. The rates of EBF for 6 months increased from 2% pre-intervention to 55.2% (95% CI 50.4-59.9) in the intervention group and 54.6% (95% CI 50.0-59.1) in the control group. The adjusted odds of EBF (after adjusting for baseline characteristics) were slightly higher in the intervention arm compared to the control arm but not significantly different: for 0-2 months (OR 1.27, 95% CI 0.55 to 2.96; p = 0.550); 0-4 months (OR 1.15; 95% CI 0.54 to 2.42; p = 0.696), and 0-6 months (OR 1.11, 95% CI 0.61 to 2.02; p = 0.718). EBF for six months significantly increased in both arms indicating potential effectiveness of using CHWs to provide home-based counselling to mothers. The lack of any difference in EBF rates in the two groups suggests potential contamination of the control arm by information reserved for the intervention arm. Nevertheless, this study indicates a great potential for use of CHWs when they are incentivized and monitored as an effective model of promotion of EBF, particularly in urban poor settings. Given the equivalence of the results in both arms, the study suggests that the basic nutritional training given to CHWs in the basic primary health care training, and/or provision of information materials may be adequate in improving EBF rates in communities. However, further investigations on this may be needed. One contribution of these findings to implementation science is the difficulty in finding an appropriate counterfactual for community-based educational interventions. ISRCTN ISRCTN83692672 . Registered 11 November 2012. Retrospectively registered.

Additive Manufacturing of Low Cost Upper Stage Propulsion Components

NASA Technical Reports Server (NTRS)

Protz, Christopher; Bowman, Randy; Cooper, Ken; Fikes, John; Taminger, Karen; Wright, Belinda

2014-01-01

NASA is currently developing Additive Manufacturing (AM) technologies and design tools aimed at reducing the costs and manufacturing time of regeneratively cooled rocket engine components. These Low Cost Upper Stage Propulsion (LCUSP) tasks are funded through NASA's Game Changing Development Program in the Space Technology Mission Directorate. The LCUSP project will develop a copper alloy additive manufacturing design process and develop and optimize the Electron Beam Freeform Fabrication (EBF3) manufacturing process to direct deposit a nickel alloy structural jacket and manifolds onto an SLM manufactured GRCop chamber and Ni-alloy nozzle. In order to develop these processes, the project will characterize both the microstructural and mechanical properties of the SLMproduced GRCop-84, and will explore and document novel design techniques specific to AM combustion devices components. These manufacturing technologies will be used to build a 25K-class regenerative chamber and nozzle (to be used with tested DMLS injectors) that will be tested individually and as a system in hot fire tests to demonstrate the applicability of the technologies. These tasks are expected to bring costs and manufacturing time down as spacecraft propulsion systems typically comprise more than 70% of the total vehicle cost and account for a significant portion of the development schedule. Additionally, high pressure/high temperature combustion chambers and nozzles must be regeneratively cooled to survive their operating environment, causing their design to be time consuming and costly to build. LCUSP presents an opportunity to develop and demonstrate a process that can infuse these technologies into industry, build competition, and drive down costs of future engines.

Affect of Early Skin-to-Skin Mother-Infant Contact in the Maintenance of Exclusive Breastfeeding: Experience in a Health Department in Spain.

PubMed

Vila-Candel, Rafael; Duke, Kiri; Soriano-Vidal, F Javier; Castro-Sánchez, Enrique

2018-05-01

Breastfeeding has been shown to result in extensive physical and psychological benefits for both the mother and the newborn. However, the rate and duration of exclusive breastfeeding (EBF) remains low worldwide. Mother-infant skin-to-skin contact (SSC) immediately after birth has demonstrated results that support the argument for breastfeeding continuation. Research aim: This study aimed to investigate the prevalence of EBF 3 months postpartum and the effect of early SSC in maintaining optimal EBF practices for mothers and their healthy newborns. We conducted an observational, retrospective study in Spain from 2013 to 2015. Pregnant women were interviewed immediately postpartum and again at 3 months postpartum regarding variables associated with breastfeeding initiation and continuation. There were 1,071 women recruited. Early SSC was performed in 92% of vaginal births but only 57% of urgent cesarean births. Of women breastfeeding at discharge, 69.5% performed SSC with their newborn. We found that 68.6% of women were exclusively breastfeeding by discharge and 46.7% by 3 months postpartum. Type of feeding at discharge, country of origin, and parity were found to be associated with each other ( p = .003, p = .001, respectively). Early SSC was also significantly associated with type of feeding at discharge, 1 month, 2 months, and 3 months postpartum ( p < .001). Hypogalactia (19.8%) was the most frequently reported factor for breastfeeding discontinuation. Breastfeeding promotion interventions are likely to improve breastfeeding rates at 3 months postpartum. Social and economic factors should be taken into account when such programs are planned to be implemented.

HIV-1 transmission and survival according to feeding options in infants born to HIV-infected women in Yaoundé, Cameroon.

PubMed

Njom Nlend, Anne Esther; Motaze, Annie Carole Nga; Sandie, Arsene; Fokam, Joseph

2018-02-19

Evidence of 24-months survival in the frame of prevention of mother-to-child transmission (PMTCT) cascade-care is scare from routine programs in sub-Saharan African (SSA) settings. Specifically, data on infant outcomes according to feeding options remain largely unknown by month-24, thus limiting its breath for public-health recommendations toward eliminating new pediatric HIV-1 infections and improving care. We sought to evaluate HIV-1 vertical transmission and infant survival rates according to feeding options. A retrospective cohort-study conducted in Yaounde from April 2008 through December 2013 among 1086 infants born to HIV-infected women and followed-up throughout the PMTCT cascade-care until 24-months. Infants with documented feeding option during their first 3 months of life (408 on Exclusive Breastfeeding [EBF], 663 Exclusive Replacement feeding [ERF], 15 mixed feeding [MF]) and known HIV-status were enrolled. HIV-1 vertical transmission, survival and feeding options were analyzed using Kaplan Meier Survival Estimate, Cox model and Schoenfeld residuals tests, at 5% statistical significance. Overall HIV-1 vertical transmission was 3.59% (39), and varied by feeding options: EBF (2.70%), ERF (3.77%), MF (20%), p = 0.002; without significance between EBF and ERF (p = 0.34). As expected, HIV-1 transmission also varied with PMTCT-interventions: 1.7% (10/566) from ART-group, 1.9% (8/411) from AZT-group, and 19.2% (21/109) from ARV-naïve group, p < 0.0001. Overall mortality was 2.58% (28), higher in HIV-infected (10.25%) vs. uninfected (2.29%) infants (p = 0.016); with a survival cumulative probability of 89.3% [79.9%-99.8%] vs. 96.4% [94.8%-97.9% respectively], p = 0.024. Mortality also varied by feeding option: ERF (2.41%), EBF (2.45%), MF (13.33%), p = 0.03; with a survival cumulative probability of 96% [94%-98%] in ERF, 96.4% [94.1%-98.8%] in EBF, and 86.67% [71.06%-100%] in MF, p = 0.04. Using Schoenfeld residuals test, only HIV status was a predictor of survival at 24 months (hazard ratio 0.23 [0.072-0.72], p = 0.01). Besides using ART for PMTCT-interventions, practice of MF also drives HIV-1 vertical transmission and mortality among HIV-infected children. Thus, throughout PMTCT option B+ cascade-care, continuous counseling on safer feeding options would to further eliminating new MTCT, optimizing response to care, and improving the life expectancy of these children in high-priority countries.

HIV serostatus and disclosure: implications for infant feeding practice in rural south Nyanza, Kenya

PubMed Central

2014-01-01

Background The World Health Organization (WHO) recommends that HIV-infected women practice exclusive breastfeeding (EBF) for the first 6 months postpartum to reduce HIV transmission. The aim of this study was to determine the effects of HIV/AIDS knowledge and other psychosocial factors on EBF practice among pregnant and postpartum women in rural Nyanza, Kenya, an area with a high prevalence of HIV. Methods Data on baseline characteristics and knowledge during pregnancy, as well as infant feeding practices 4–8 weeks after the birth were obtained from 281 pregnant women recruited from nine antenatal clinics. Factors examined included: fear of HIV/AIDS stigma, male partner reactions, lack of disclosure to family members, knowledge of prevention of mother-to-child transmission (PMTCT) and mental health. In the analysis, comparisons were made using chi-squared and t-test methods as well as logistic multivariate regression models. Results There were high levels of anticipated stigma 171(61.2%), intimate partner violence 57(20.4%) and postpartum depression 29(10.1%) and low levels of disclosure among HIV positive women 30(31.3%). The most significant factors determining EBF practice were hospital delivery (aOR = 2.1 95% CI 1.14-3.95) HIV positive serostatus (aOR 2.5 95% CI 1.23-5.27), and disclosure of HIV-positive serostatus (aOR 2.9 95% CI 1.31-6.79). Postpartum depression and PMTCT knowledge were not associated with EBF (aOR 1.1 95% CI 0.47-2.62 and aOR 1.2 95% CI 0.64-2.24) respectively. Conclusions Health care workers and counselors need to receive support in order to improve skills required for diagnosing, monitoring and managing psychosocial aspects of the care of pregnant and HIV positive women including facilitating disclosure to male partners in order to improve both maternal and child health outcomes. PMID:24754975

Effect of Breastfeeding Promotion on Early Childhood Caries and Breastfeeding Duration among 5 Year Old Children in Eastern Uganda: A Cluster Randomized Trial

PubMed Central

Birungi, Nancy; Fadnes, Lars T.; Okullo, Isaac; Kasangaki, Arabat; Nankabirwa, Victoria; Ndeezi, Grace; Tumwine, James K.; Tylleskär, Thorkild; Lie, Stein Atle; Åstrøm, Anne Nordrehaug

2015-01-01

Background Although several studies have shown short term health benefits of exclusive breastfeeding (EBF), its long term consequences have not been studied extensively in low-income contexts. This study assessed the impact of an EBF promotion initiative for 6 months on early childhood caries (ECC) and breastfeeding duration in children aged 5 years in Mbale, Eastern Uganda. Methods Participants were recruited from the Ugandan site of the PROMISE- EBF cluster randomised trial (ClinicalTrials.gov no: NCT00397150). A total of 765 pregnant women from 24 clusters were included in the ratio 1:1 to receive peer counselled promotion of EBF as the intervention or standard of care. At the 5 year follow-up, ECC was recorded under field conditions using the World Health Organization’s decayed missing filled tooth (dmft) index. Adjusted negative binomial and linear regression were used in the analysis. Results Mean breastfeeding duration in the intervention and control groups (n=417) were 21.8 (CI 20.7–22.9) and 21.3(CI 20.7–21.9) months, respectively. The mean dmft was 1.5 (standard deviation [SD] 2.9) and 1.7 (SD 2.9) in the intervention and control groups, respectively. Corresponding prevalence estimates of ECC were 38% and 41%. Negative binomial regression analysis adjusted for cluster effects and loss-to-follow-up by inverse probability weights (IPW) showed an incidence-rate ratio (IRR) of 0.91 (95% CI 0.65–1.2). Comparing the effect of the trial arm on breastfeeding duration showed a difference in months of 0.48 (-0.72 to 1.7). Conclusion PROMISE EBF trial did not impact on early childhood caries or breastfeeding duration at 5 years of age. This study contributes to the body of evidence that promotion of exclusive breastfeeding does not raise oral health concerns. However, the high burden of caries calls for efforts to improve the oral health condition in this setting. Trial Registration ClinicalTrials.gov NCT00397150 PMID:25938681

Changes in knowledge, attitude and involvement of fathers in supporting exclusive breastfeeding: a community-based intervention study in a rural area of Vietnam.

PubMed

Bich, Tran Huu; Cuong, Nguyen Manh

2017-02-01

To test the hypotheses of positive changes of fathers' knowledge, attitude and involvement in supporting exclusive breastfeeding (EBF) after receiving breastfeeding education materials and counseling services. A quasi-experimental, pre-test-post-test, non-equivalent control group design was used. At baseline, 251 and 241 pregnant women and their husbands were enrolled into the intervention and control groups, respectively. The 1-year intervention targeting fathers included mass media, game show-style community events, group and individual counseling at health facilities and home visits. Compared to fathers in the control group, fathers in the intervention group had higher BF knowledge scores and higher attitude scores reflecting more positive attitudes toward early initiation of BF and 6 months EBF. Fathers in the intervention group were also more likely to report active involvement in supporting mothers to practice EBF during antenatal and postpartum periods. The community-based education model should be maintained and considered for conducting further test in wider application to mobilize fathers in supporting EBF.

ZNF423 and ZNF521: EBF1 Antagonists of Potential Relevance in B-Lymphoid Malignancies

PubMed Central

Mesuraca, Maria; Chiarella, Emanuela; Scicchitano, Stefania; Codispoti, Bruna; Giordano, Marco; Nappo, Giovanna; Bond, Heather M.; Morrone, Giovanni

2015-01-01

The development of the B-lymphoid cell lineage is tightly controlled by the concerted action of a network of transcriptional and epigenetic regulators. EBF1, a central component of this network, is essential for B-lymphoid specification and commitment as well as for the maintenance of the B-cell identity. Genetic alterations causing loss of function of these B-lymphopoiesis regulators have been implicated in the pathogenesis of B-lymphoid malignancies, with particular regard to B-cell acute lymphoblastic leukaemias (B-ALLs), where their presence is frequently detected. The activity of the B-cell regulatory network may also be disrupted by the aberrant expression of inhibitory molecules. In particular, two multi-zinc finger transcription cofactors named ZNF423 and ZNF521 have been characterised as potent inhibitors of EBF1 and are emerging as potentially relevant contributors to the development of B-cell leukaemias. Here we will briefly review the current knowledge of these factors and discuss the importance of their functional cross talk with EBF1 in the development of B-cell malignancies. PMID:26788497

Pre-gestational excessive weight and duration of breast-feeding.

PubMed

Sotero, Andréa M; Ferreira, Haroldo da S; Assunção, Monica L; de Lira, Pedro Israel C

2018-02-01

To investigate whether pre-gestational obesity interferes with the duration of breast-feeding. A cross-sectional study was carried out with a population-based probabilistic sample. The dependent variables were exclusive breast-feeding (EBF) and breast-feeding (BF), as defined by the WHO. The classification of pre-gestational nutritional status was based on the pre-gestational BMI category. A sample of 418 mother-infant pairs from the state of Alagoas, Brazil. The median duration of EBF was 1·9 months (60d), while that of BF was 8·2 months (250d). According to multiple linear regression analysis, the factors that negatively and independently affected the duration of EBF were pre-gestational BMI≥30·0 kg/m2 (-51·9d, 95 % CI -80·4, -23·4), maternal schooling≤9 years (-30·8d, 95 % CI -54·7, -6·9), no prior lactation experience (-29·0d, 95 % CI -45·6, -11·5) and infant pacifier use (-41·4d; 95 % CI 54·5, -28·2). For BF, a higher weaning rate was observed during the first days after birth among children of pre-gestational obese mothers. The results suggest that higher pre-gestational BMI is associated with shorter duration of EBF and BF. Prenatal care provides a privileged opportunity to promote nutritional education, better nutritional status of pregnant woman, and greater success with EBF up to 6 months of age and with longer BF.

Duration of breast-feeding and the risk of childhood allergic diseases in a developing country.

PubMed

Ehlayel, Mohammad S; Bener, Abdulbari

2008-01-01

Exclusive breast-feeding (EBF) seems to reduce risk of allergies in the western countries, but there are few reports from developing countries. The purpose of this study was to assess the effect of EBF on the development of allergic diseases and eczema in a developing country. This is a cross-sectional survey done at the well-baby clinics of 11 primary health centers, Hamad Medical Corporation, Qatar. A multistage sampling design was used and a representative sample of 1500 children (0-5 years old) and mothers (18-47 years old) were surveyed between October 2006 and September 2007. Of them, 1278 mothers (85.2%) participated in the study. A confidential, anonymous questionnaire assessing breast-feeding and allergic diseases was completed by mothers bringing children for immunization. Questionnaire included allergic rhinitis, wheezing, eczema, type and duration of breast-feeding, parental smoking habits, number of siblings, family income, maternal education, and parental allergies. Univariate and multivariate statistical methods were performed for statistical analysis. More than one-half of the infants (59.3%) were on EBF. Length of breast-feeding was associated with maternal age. Prevalence of eczema (19.4%), allergic rhinitis (22.6%), and wheezing (12.7%) were significantly less frequent in those with prolonged (>6 months) compared with short-term fed infants. The association between EBF and eczema tended to be similar in children with a positive family history of atopy (p < 0.001) and eczema (p < 0.001) compared with those without. In children of developing countries, prolonged breast-feeding reduces the risk of developing allergic diseases and eczema even in the presence of maternal allergy, where it might be a practical, effective preventive measure.

Pacifier use and interruption of exclusive breastfeeding: Systematic review and meta-analysis.

PubMed

Buccini, Gabriela Dos Santos; Pérez-Escamilla, Rafael; Paulino, Larissa Munari; Araújo, Clarice Lopes; Venancio, Sonia Isoyama

2017-07-01

Identifying modifiable risk factor for exclusive breastfeeding (EBF) interruption is key for improving child health globally. There is no consensus about the effect of pacifier use on EBF interruption. Thus, the aim of this systematic review was to investigate the association between pacifier use and EBF interruption during the first six month. A search of CINAHL, Scopus, Web of Science, LILACS and Medline; from inception through 30 December 2014 without restriction of language yielded 1,866 publications (PROSPERO protocol CRD42014014527). Predetermined inclusion/exclusion criteria peer reviewed yielded 46 studies: two clinical trials, 20 longitudinal, and 24 cross-sectional studies. Meta-analysis was performed and meta-regression explored heterogeneity across studies. The pooled effect of the association between pacifier use and EBF interruption was 2.48 OR (95% CI = 2.16-2.85). Heterogeneity was explained by the study design (40.2%), followed by differences in the measurement and categorization of pacifier use, the methodological quality of the studies and the socio-economic context. Two RCT's with very limited external validity found a null association, but 44 observational studies, including 20 prospective cohort studies, did find a consistent association between pacifier use and risk of EBF interruption (OR = 2.28; 95% CI = 1.78-2.93). Our findings support the current WHO recommendation on pacifier use as it focuses on the risk of poor breastfeeding outcomes as a result of pacifier use. Future studies that take into account the risks and benefits of pacifier use are needed to clarify this recommendation. © 2016 John Wiley & Sons Ltd.

Influence of maternity leave on exclusive breastfeeding.

PubMed

Monteiro, Fernanda R; Buccini, Gabriela Dos S; Venâncio, Sônia I; da Costa, Teresa H M

To describe the profile of women with children aged under 4 months living in the Brazilian state capitals and in the Federal District according to their working status and to analyze the influence of maternity leave on exclusive breastfeeding (EBF) among working women. This was a cross-sectional study with data extracted from the II National Maternal Breastfeeding Prevalence Survey carried out in 2008. Initially, a descriptive analysis of the profile of 12,794 women was performed, according to their working status and maternity leave and the frequency of maternity leave in the Brazilian regions and capitals. The study used a multiple model to identify the influence of maternity leave on EBF interruption, including 3766 women who declared they were working and were on maternity leave at the time of the interview. The outcome assessed in the study was the interruption of the EBF, classified by the WHO. Regarding the working status of the mothers, 63.4% did not work outside of their homes and among those who worked, 69.8% were on maternity leave. The largest prevalence among workers was of women older than 35 years of age, with more than 12 years of schooling, primiparous and from the Southeast and South regions. The lack of maternity leave increased by 23% the chance of EBF interruption. Maternity leave contributed to increase the prevalence of EBF in the Brazilian states capitals, supporting the importance of increasing the maternity leave period from four to six months. Copyright © 2017 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.

High performance of nitrogen and phosphorus removal in an electrolysis-integrated biofilter.

PubMed

Gao, Y; Xie, Y W; Zhang, Q; Yu, Y X; Yang, L Y

A novel electrolysis-integrated biofilter system was developed in this study to evaluate the intensified removal of nitrogen and phosphorus from contaminated water. Two laboratory-scale biofilter systems were established, one with electrolysis (E-BF) and one without electrolysis (BF) as control. The dynamics of intensified nitrogen and phosphorus removal and the changes of inflow and outflow water qualities were also evaluated. The total nitrogen (TN) removal rate was 94.4% in our newly developed E-BF, but only 74.7% in the control BF. Ammonium removal rate was up to 95% in biofilters with or without electrolysis integration with an influent ammonium concentration of 40 mg/L, and the accumulation of nitrate and nitrite was much lower in the effluent of E-BF than that of BF. Thus electrolysis plays an important role in TN removal especially the nitrate and nitrite removal. Phosphorus removal was significantly enhanced, exceeding 90% in E-BF by chemical precipitation, physical adsorption, and flocculation of phosphorus because of the in situ formation of ferric ions by the anodizing of sacrificial iron anodes. Results from this study indicate that the electrolysis integrated biofilter is a promising solution for intensified nitrogen and phosphorus removal.

Effects of an educational technology on self-efficacy for breastfeeding and practice of exclusive breastfeeding.

PubMed

Javorski, Marly; Rodrigues, Andreyna Javorski; Dodt, Regina Cláudia Melo; Almeida, Paulo César de; Leal, Luciana Pedrosa; Ximenes, Lorena Barbosa

2018-06-11

To evaluate the effects of using a flipchart (serial album) on maternal self-efficacy in breastfeeding and its effects on exclusive breastfeeding (EBF) in children's first two months of life. Clinical trial in Recife, Northeastern Brazil, with 112 women in the third trimester of gestation, randomly distributed in intervention group (IG) and control group (CG). The intervention was the use of the flipchart in IG. Data collection was performed through interviews in the prenatal period, and telephone contact at second, fourth and eighth weeks postpartum. The Breastfeeding Self-Efficacy Scale-Short-Form (BSES-SF) was used to measure self-efficacy scores. In the analysis, was used descriptive, bivariate statistics through tests of comparisons of proportions and means, and relative risk assessment. There was a statistically significant difference in mean values of self-efficacy scores between women in the IG and CG (p<0.001) and in EBF rates (p<0.001). The probability of exclusively breastfeeding in IG was twice as high than in CG (RR 2.2, CI 1.51-3.21). The use of a flipchart as an educational tool had positive effects on self-efficacy scores for breastfeeding and in maintenance of EBF in the IG. Brazilian Registry of Clinical Trials: RBR-5N7K99.

Interventions in exclusive breastfeeding: a systematic review.

PubMed

Bevan, Gillian; Brown, Michelle

Now recognised as a worldwide public health issue, the significance of promoting and encouraging exclusive breastfeeding (EBF) has been acknowledged by the World Health Organization (WHO) and the United Nations Children's Fund (UNICEF). Documented policies about the importance of facilitating the support of breastfeeding women is currently receiving worldwide recognition (WHO, 2011; WHO and UNICEF, 2003). This literature review will examine provision of support mechanisms for breastfeeding mothers, focusing on peer support in encouraging the starting and maintaining of EBF. Consideration will also be given to any barriers that may prevent higher success rates, as cultural and educational factors may have a significant impact on the starting and maintaining of EBF. These factors must be considered when starting support groups, networks or activities that aim to address this significant public health issue.

Specific Infant Feeding Practices Do Not Consistently Explain Variation in Anthropometry at Age 1 Year in Urban United States, Mexico, and China Cohorts12

PubMed Central

Woo, Jessica G.; Guerrero, M. Lourdes; Ruiz-Palacios, Guillermo M.; Peng, Yong-mei; Herbers, Patricia M.; Yao, Wen; Ortega, Hilda; Davidson, Barbara S.; McMahon, Robert J.; Morrow, Ardythe L.

2013-01-01

Infant feeding practices generally influence infant growth, but it is unclear how introduction of specific foods affects growth across global populations. We studied 3 urban populations in the Global Exploration of Human Milk study to determine the association between infant feeding and anthropometry at 1 y of age. Three hundred sixty-five breastfeeding mother-infant pairs (120 US, 120 China, and 125 Mexico) were recruited soon after the infant’s birth. Enrollment required agreement to breastfeed ≥75% for at least 3 mo. Weekly, 24-h, food frequency data were conducted on infants for 1 y and exclusive breastfeeding (EBF) duration and timing of specific complementary food introduction were calculated. Weight and length were measured at age 1 y and anthropometry Z-scores calculated using WHO standards. Cohorts in the 3 urban populations (Shanghai, China; Cincinnati, USA; and Mexico City, Mexico) differed by median EBF duration (5, 14, and 7 wk, respectively; P < 0.001), timing of introduction of meat/eggs/legumes (4.8, 9.3, and 7.0 mo, respectively; P < 0.0001), and other feeding practices. By age 1 y, infants in Shanghai were heavier and longer than Cincinnati and Mexico City infants (P < 0.001). Adjusting for nonfeeding covariates, the only feeding variable associated with anthropometry was EBF duration, which was modestly inversely associated with weight-for-age but not length-for-age or BMI Z-scores at 1 y. Although feeding variables differed by cohort, their impact on anthropometry differences was not consistent among cohorts. Overall, across these urban, international, breast-fed cohorts, differences in specific feeding practices did not explain the significant variation in anthropometry. PMID:23236024

DNA-binding by Haemophilus influenzae and Escherichia coli YbaB, members of a widely-distributed bacterial protein family.

PubMed

Cooley, Anne E; Riley, Sean P; Kral, Keith; Miller, M Clarke; DeMoll, Edward; Fried, Michael G; Stevenson, Brian

2009-07-13

Genes orthologous to the ybaB loci of Escherichia coli and Haemophilus influenzae are widely distributed among eubacteria. Several years ago, the three-dimensional structures of the YbaB orthologs of both E. coli and H. influenzae were determined, revealing a novel "tweezer"-like structure. However, a function for YbaB had remained elusive, with an early study of the H. influenzae ortholog failing to detect DNA-binding activity. Our group recently determined that the Borrelia burgdorferi YbaB ortholog, EbfC, is a DNA-binding protein. To reconcile those results, we assessed the abilities of both the H. influenzae and E. coli YbaB proteins to bind DNA to which B. burgdorferi EbfC can bind. Both the H. influenzae and the E. coli YbaB proteins bound to tested DNAs. DNA-binding was not well competed with poly-dI-dC, indicating some sequence preferences for those two proteins. Analyses of binding characteristics determined that both YbaB orthologs bind as homodimers. Different DNA sequence preferences were observed between H. influenzae YbaB, E. coli YbaB and B. burgdorferi EbfC, consistent with amino acid differences in the putative DNA-binding domains of these proteins. Three distinct members of the YbaB/EbfC bacterial protein family have now been demonstrated to bind DNA. Members of this protein family are encoded by a broad range of bacteria, including many pathogenic species, and results of our studies suggest that all such proteins have DNA-binding activities. The functions of YbaB/EbfC family members in each bacterial species are as-yet unknown, but given the ubiquity of these DNA-binding proteins among Eubacteria, further investigations are warranted.

Replication of Early B-cell Factor 1 (EBF1) Gene-by-psychosocial Stress Interaction Effects on Central Adiposity in a Korean Population.

PubMed

Kim, Hyun-Jin; Min, Jin-Young; Min, Kyoung-Bok

2016-09-01

Central obesity plays a major role in the development of many chronic diseases, including cardiovascular disease and cancer. Chronic stress may be involved in the pathophysiology of central obesity. Although several large-scale genome-wide association studies have reported susceptibility genes for central adiposity, the effects of interactions between genes and psychosocial stress on central adiposity have rarely been examined. A recent study focusing on Caucasians discovered the novel gene early B-cell factor 1 (EBF1) , which was associated with central obesity-related traits via interactions with stress levels. We aimed to evaluate EBF1 gene-by-stress interaction effects on central adiposity traits, including visceral adipose tissue (VAT), in Korean adults. A total of 1467 Korean adults were included in this study. We selected 22 single-nucleotide polymorphisms (SNPs) in the EBF1 gene and analyzed their interactions with stress on central adiposity using additive, dominant, and recessive genetic modeling. The four SNPs that had strong linkage disequilibrium relationships (rs10061900, rs10070743, rs4704967, and rs10056564) demonstrated significant interactions with the waist-hip ratio in the dominant model ( p int <0.007). In addition, two other SNPs (rs6556377 and rs13180086) were associated with VAT by interactions with stress levels, especially in the recessive genetic model ( p int <0.007). As stress levels increased, the mean values of central adiposity traits according to SNP genotypes exhibited gradual but significant changes ( p <0.05). These results suggest that the common genetic variants for EBF1 are associated with central adiposity through interactions with stress levels, emphasizing the importance of managing stress in the prevention of central obesity.

Breast-feeding counselling mitigates the negative association of domestic violence on exclusive breast-feeding duration in rural Bangladesh. The MINIMat randomized trial.

PubMed

Frith, Amy L; Ziaei, Shirin; Naved, Ruchira Tabassum; Khan, Ashraful Islam; Kabir, Iqbal; Ekström, Eva-Charlotte

2017-10-01

To determine if exclusive breast-feeding counselling modifies the association of experience of any lifetime or specific forms of domestic violence (DV) on duration of exclusive breast-feeding (EBF). In the MINIMat trial pregnant women were randomized to receive either usual health messages (UHM) or usual health messages with breast-feeding counselling (BFC) in eight visits. During pregnancy (30 weeks), lifetime experience of any or specific forms of DV was measured. Infant feeding practice information was collected from 0 to 6 months at 15 d intervals. Matlab, Bangladesh. Pregnant and postpartum women (n 3186) and their infants. Among women in the UHM group, those who had experienced any lifetime DV exclusively breast-fed for a shorter duration than women who did not experience any lifetime DV (P=0·02). There was no difference, however, in duration of EBF among women in the BFC group based on their experience of any lifetime DV exposure (P=0·48). Using Cox regression analysis, there was an interaction of exposure to any lifetime DV, sexual violence and controlling behaviour, and counselling group with duration of breast-feeding at or before 6 months (P-interaction≤0·08). Among the UHM group, experience of any lifetime DV, sexual violence or controlling behaviour was associated with fewer days of EBF (P<0·05). In contrast, among the BFC group, experience of DV was not associated with duration of EBF. The experience of DV compromises EBF and the support of breast-feeding counselling programmes could assist this vulnerable group towards better infant feeding practices.

Vibration acceleration promotes bone formation in rodent models

PubMed Central

Uchida, Ryohei; Nakata, Ken; Kawano, Fuminori; Yonetani, Yasukazu; Ogasawara, Issei; Nakai, Naoya; Mae, Tatsuo; Matsuo, Tomohiko; Tachibana, Yuta; Yokoi, Hiroyuki; Yoshikawa, Hideki

2017-01-01

All living tissues and cells on Earth are subject to gravitational acceleration, but no reports have verified whether acceleration mode influences bone formation and healing. Therefore, this study was to compare the effects of two acceleration modes, vibration and constant (centrifugal) accelerations, on bone formation and healing in the trunk using BMP 2-induced ectopic bone formation (EBF) mouse model and a rib fracture healing (RFH) rat model. Additionally, we tried to verify the difference in mechanism of effect on bone formation by accelerations between these two models. Three groups (low- and high-magnitude vibration and control-VA groups) were evaluated in the vibration acceleration study, and two groups (centrifuge acceleration and control-CA groups) were used in the constant acceleration study. In each model, the intervention was applied for ten minutes per day from three days after surgery for eleven days (EBF model) or nine days (RFH model). All animals were sacrificed the day after the intervention ended. In the EBF model, ectopic bone was evaluated by macroscopic and histological observations, wet weight, radiography and microfocus computed tomography (micro-CT). In the RFH model, whole fracture-repaired ribs were excised with removal of soft tissue, and evaluated radiologically and histologically. Ectopic bones in the low-magnitude group (EBF model) had significantly greater wet weight and were significantly larger (macroscopically and radiographically) than those in the other two groups, whereas the size and wet weight of ectopic bones in the centrifuge acceleration group showed no significant difference compared those in control-CA group. All ectopic bones showed calcified trabeculae and maturated bone marrow. Micro-CT showed that bone volume (BV) in the low-magnitude group of EBF model was significantly higher than those in the other two groups (3.1±1.2mm3 v.s. 1.8±1.2mm3 in high-magnitude group and 1.3±0.9mm3 in control-VA group), but BV in the centrifuge acceleration group had no significant difference compared those in control-CA group. Union rate and BV in the low-magnitude group of RFH model were also significantly higher than those in the other groups (Union rate: 60% v.s. 0% in the high-magnitude group and 10% in the control-VA group, BV: 0.69±0.30mm3 v.s. 0.15±0.09mm3 in high-magnitude group and 0.22±0.17mm3 in control-VA group). BV/TV in the low-magnitude group of RFH model was significantly higher than that in control-VA group (59.4±14.9% v.s. 35.8±13.5%). On the other hand, radiographic union rate (10% in centrifuge acceleration group v.s. 20% in control-CA group) and micro-CT parameters in RFH model were not significantly different between two groups in the constant acceleration studies. Radiographic images of non-union rib fractures showed cartilage at the fracture site and poor new bone formation, whereas union samples showed only new bone. In conclusion, low-magnitude vibration acceleration promoted bone formation at the trunk in both BMP-induced ectopic bone formation and rib fracture healing models. However, the micro-CT parameters were not similar between two models, which suggested that there might be difference in the mechanism of effect by vibration between two models. PMID:28264058

Vibration acceleration promotes bone formation in rodent models.

PubMed

Uchida, Ryohei; Nakata, Ken; Kawano, Fuminori; Yonetani, Yasukazu; Ogasawara, Issei; Nakai, Naoya; Mae, Tatsuo; Matsuo, Tomohiko; Tachibana, Yuta; Yokoi, Hiroyuki; Yoshikawa, Hideki

2017-01-01

All living tissues and cells on Earth are subject to gravitational acceleration, but no reports have verified whether acceleration mode influences bone formation and healing. Therefore, this study was to compare the effects of two acceleration modes, vibration and constant (centrifugal) accelerations, on bone formation and healing in the trunk using BMP 2-induced ectopic bone formation (EBF) mouse model and a rib fracture healing (RFH) rat model. Additionally, we tried to verify the difference in mechanism of effect on bone formation by accelerations between these two models. Three groups (low- and high-magnitude vibration and control-VA groups) were evaluated in the vibration acceleration study, and two groups (centrifuge acceleration and control-CA groups) were used in the constant acceleration study. In each model, the intervention was applied for ten minutes per day from three days after surgery for eleven days (EBF model) or nine days (RFH model). All animals were sacrificed the day after the intervention ended. In the EBF model, ectopic bone was evaluated by macroscopic and histological observations, wet weight, radiography and microfocus computed tomography (micro-CT). In the RFH model, whole fracture-repaired ribs were excised with removal of soft tissue, and evaluated radiologically and histologically. Ectopic bones in the low-magnitude group (EBF model) had significantly greater wet weight and were significantly larger (macroscopically and radiographically) than those in the other two groups, whereas the size and wet weight of ectopic bones in the centrifuge acceleration group showed no significant difference compared those in control-CA group. All ectopic bones showed calcified trabeculae and maturated bone marrow. Micro-CT showed that bone volume (BV) in the low-magnitude group of EBF model was significantly higher than those in the other two groups (3.1±1.2mm3 v.s. 1.8±1.2mm3 in high-magnitude group and 1.3±0.9mm3 in control-VA group), but BV in the centrifuge acceleration group had no significant difference compared those in control-CA group. Union rate and BV in the low-magnitude group of RFH model were also significantly higher than those in the other groups (Union rate: 60% v.s. 0% in the high-magnitude group and 10% in the control-VA group, BV: 0.69±0.30mm3 v.s. 0.15±0.09mm3 in high-magnitude group and 0.22±0.17mm3 in control-VA group). BV/TV in the low-magnitude group of RFH model was significantly higher than that in control-VA group (59.4±14.9% v.s. 35.8±13.5%). On the other hand, radiographic union rate (10% in centrifuge acceleration group v.s. 20% in control-CA group) and micro-CT parameters in RFH model were not significantly different between two groups in the constant acceleration studies. Radiographic images of non-union rib fractures showed cartilage at the fracture site and poor new bone formation, whereas union samples showed only new bone. In conclusion, low-magnitude vibration acceleration promoted bone formation at the trunk in both BMP-induced ectopic bone formation and rib fracture healing models. However, the micro-CT parameters were not similar between two models, which suggested that there might be difference in the mechanism of effect by vibration between two models.

The Effects of Mild Gestational Hyperglycemia on Exclusive Breastfeeding Cessation.

PubMed

Verd, Sergio; de Sotto, Diego; Fernández, Consuelo; Gutiérrez, Antonio

2016-11-19

Gestational diabetes increases the risk of a range of adverse perinatal outcomes, including breastfeeding failure, but the best cut-off point for gestational diabetes is unknown. The purpose of this study was to evaluate the association between mild gestational glucose tolerance impairment and the early cessation of exclusive breastfeeding (EBF). This is an observational study of 768 women with full term pregnancies that were screened for gestational diabetes at 24-28 weeks gestation. Subjects were divided into two groups: those with a normal 1-h glucose challenge test and those with an elevated 1-h glucose challenge test but still did not qualify for gestational diabetes. We constructed multivariable logistic regression models using data from 616 women with normal gestational glucose tolerance and 152 women with an isolated positive 1-h glucose challenge test. The risk of early exclusive breastfeeding cessation was found to increase in women with mildly impaired glucose tolerance during pregnancy (adjusted OR, 1.65; 95% CI: 1.11, 2.45). Risks of early EBF cessation were also independently associated with the amount of neonatal weight loss and admission to the neonatal ward. Instead, parity was associated with a decreased risk for shorter EBF duration. Insulin resistance-even in the absence of gestational diabetes mellitus-may be an impeding factor for EBF.

Knowledge and Attitude towards Exclusive Breast Feeding among Mothers Attending Antenatal and Immunization Clinic at Dabat Health Center, Northwest Ethiopia: A Cross-Sectional Institution Based Study.

PubMed

Alamirew, Mulugeta Wassie; Bayu, Netsanet Habte; Birhan Tebeje, Nigusie; Kassa, Selam Fiseha

2017-01-01

To assess knowledge and attitude towards exclusive breast feeding among mothers attending antenatal care and immunization clinic in Dabat Health Center, Northwest Ethiopia, 2016. Institutional based descriptive cross-sectional study was conducted. The data was collected by using pretested, structured interview based questionnaires. The data were entered and analyzed using SPSS version 20. A total of 384 participants were included in the study with a response rate of 100%. The majority were in the age groups of 20-30 (66.9%) and the mean age was 27.65; 325 (84.6%) were Orthodox Christianity followers. Majority were of Amhara ethnicity 370 (96.4%). Based on knowledge score, 268 (69.8%) were grouped as having good knowledge and regarding attitudinal score, 92 (24%) of the study participants were categorized as having negative attitude towards exclusive breast feeding (EBF) and the remaining 292 (76%) were categorized as having positive attitude. In this study, the knowledge of study participant mothers towards EBF is low which is less than three-fourths; however positive attitude towards EBF is more than three-fourths in this study. The authors recommend that health care workers who work in the areas of maternal and child health clinic should give appropriate information about EBF.

Pattern and determinants of breast feeding and contraceptive practices among mothers within six months postpartum.

PubMed

Kunwar, Shipra; Faridi, Mohammad M A; Singh, Shivani; Zahra, Fatima; Alizaidi, Zeashan

2010-08-01

The present study aims to determine the patterns of breast feeding, return of menstruation, and contraceptive practices in the first six months postpartum in women visiting the outpatient department at a teaching hospital in Lucknow, Northern India. Mothers of infants between six to eight months of age visiting the outpatient department of Era's Lucknow Medical College were interviewed regarding breast feeding practices, return of menstruation, sexual activity, and contraceptive practices within the first six months postpartum using a structured questionnaire. Of all women interviewed only 75.8% practiced exclusive breast feeding with the mean duration of exclusive breast feeding (EBF) being 3.5 months with only 41% practicing EBF for six months, 28% were sexually active within six weeks postpartum, 64.5% women had a return of menstruation within six months. Contraception was practiced by only 54.4% women with a barrier method such as a condom, being the most common. Better education was the only factor significantly affecting EBF (p < 0.004) and use of contraception (p < 0.027). There were a total of 10 pregnancies within six months postpartum. In conclusion, optimal breast feeding practices are poor in this part of the country and lactational amenorrhoea cannot be effectively and reliably used as a method of contraception. Therefore, optimal breast feeding practices, timely introduction of contraception and institutional delivery need to be encouraged.

The Evolution of Structural Order as a Measure of Thermal History of Coke in the Blast Furnace

NASA Astrophysics Data System (ADS)

Lundgren, Maria; Khanna, Rita; Ökvist, Lena Sundqvist; Sahajwalla, Veena; Björkman, Bo

2014-04-01

Investigations were carried out on cokes heat treated in the laboratory and on cokes extracted from the experimental blast furnace (EBF) raceway and hearth. X-ray diffraction (XRD) measurements were performed to investigate changes in structural order ( L c), chemical transformations in coke ash along with comparative thermodynamic equilibrium studies and the influence of melt. Three data processing approaches were used to compute L c values as a function of temperature and time and linear correlations were established between L c and heat treatment temperatures during laboratory investigations. These were used to estimate temperatures experienced by coke in various regions of EBF and estimated raceway temperatures were seen to follow the profile of combustion peak. The MgAl2O4 spinel was observed in coke submerged in slag during laboratory studies and in cokes found further into the raceway. Coke in contact with hot metal showed XRD peaks corresponding to presence of Fe3Si. The intensity of SiO2 peak in coke ash was seen to decrease with increasing temperature and disappeared at around 1770 K (1500 °C) due to the formation of SiC. This study has shown that the evolution of structural order and chemical transformations in coke could be used to estimate its thermal history in blast furnaces.

Implementing a WIC-Based Intervention to Promote Exclusive Breastfeeding: Challenges, Facilitators, and Adaptive Strategies.

PubMed

Eldridge, Johanna D; Hartnett, Josette O; Lee, Furrina F; Sekhobo, Jackson P; Edmunds, Lynn S

Understand factors that contributed to the implementation of a successful multicomponent intervention to promote exclusive breastfeeding (EBF) within Special Supplemental Nutrition Program for Woman, Infants, and Children (WIC) clinics. Qualitative study of staff implementers' experiences using implementation status reports, facilitated group discussion immediately after implementation, and WIC administrative data. WIC staff from 12 clinics participated in an EBF Learning Community composed of 8 intervention trainings and ongoing support from trainers and peers. A total of 47 WIC staff including 11 directors, 20 other administrators, 8 nutritionists, and 6 peer counselors. A WIC-integrated EBF promotion initiative, supported through a Learning Community, composed of prenatal screening, tailored trimester-specific counseling, and timely postpartum follow-up. Challenges and facilitators to implementation within clinics. Iterative qualitative analysis using directed, emergent, and thematic coding. Implementation experiences were characterized by (1) perceived benefits of implementation, including improved EBF knowledge and counseling confidence among staff; and (2) managing implementation, including responding to challenges posed by clinic settings (resources, routine practices, values, and perceptions of mothers) through strategies such as adapting clinic practices and intervention components. Implementation was shaped by clinic setting and adaptive strategies. Future WIC interventions may benefit from formal consideration of intervention fit with local clinic setting and allowable adaptations. Copyright © 2017 Society for Nutrition Education and Behavior. Published by Elsevier Inc. All rights reserved.

Knowledge and Attitude towards Exclusive Breast Feeding among Mothers Attending Antenatal and Immunization Clinic at Dabat Health Center, Northwest Ethiopia: A Cross-Sectional Institution Based Study

PubMed Central

Kassa, Selam Fiseha

2017-01-01

Introduction To assess knowledge and attitude towards exclusive breast feeding among mothers attending antenatal care and immunization clinic in Dabat Health Center, Northwest Ethiopia, 2016. Methodology Institutional based descriptive cross-sectional study was conducted. The data was collected by using pretested, structured interview based questionnaires. The data were entered and analyzed using SPSS version 20. Result A total of 384 participants were included in the study with a response rate of 100%. The majority were in the age groups of 20–30 (66.9%) and the mean age was 27.65; 325 (84.6%) were Orthodox Christianity followers. Majority were of Amhara ethnicity 370 (96.4%). Based on knowledge score, 268 (69.8%) were grouped as having good knowledge and regarding attitudinal score, 92 (24%) of the study participants were categorized as having negative attitude towards exclusive breast feeding (EBF) and the remaining 292 (76%) were categorized as having positive attitude. Conclusion In this study, the knowledge of study participant mothers towards EBF is low which is less than three-fourths; however positive attitude towards EBF is more than three-fourths in this study. The authors recommend that health care workers who work in the areas of maternal and child health clinic should give appropriate information about EBF. PMID:29312785

Induction of Epstein-Barr Virus Oncoprotein LMP1 by Transcription Factors AP-2 and Early B Cell Factor

PubMed Central

Noda, Chieko; Narita, Yohei; Watanabe, Takahiro; Yoshida, Masahiro; Ashio, Keiji; Sato, Yoshitaka; Goshima, Fumi; Kanda, Teru; Yoshiyama, Hironori; Tsurumi, Tatsuya; Kimura, Hiroshi

2016-01-01

ABSTRACT Latent membrane protein 1 (LMP1) is a major oncogene essential for primary B cell transformation by Epstein-Barr virus (EBV). Previous studies suggested that some transcription factors, such as PU.1, RBP-Jκ, NF-κB, and STAT, are involved in this expression, but the underlying mechanism is unclear. Here, we identified binding sites for PAX5, AP-2, and EBF in the proximal LMP1 promoter (ED-L1p). We first confirmed the significance of PU.1 and POU domain transcription factor binding for activation of the promoter in latency III. We then focused on the transcription factors AP-2 and early B cell factor (EBF). Interestingly, among the three AP-2-binding sites in the LMP1 promoter, two motifs were also bound by EBF. Overexpression, knockdown, and mutagenesis in the context of the viral genome indicated that AP-2 plays an important role in LMP1 expression in latency II in epithelial cells. In latency III B cells, on the other hand, the B cell-specific transcription factor EBF binds to the ED-L1p and activates LMP1 transcription from the promoter. IMPORTANCE Epstein-Barr virus (EBV) latent membrane protein 1 (LMP1) is crucial for B cell transformation and oncogenesis of other EBV-related malignancies, such as nasopharyngeal carcinoma and T/NK lymphoma. Its expression is largely dependent on the cell type or condition, and some transcription factors have been implicated in its regulation. However, these previous reports evaluated the significance of specific factors mostly by reporter assay. In this study, we prepared point-mutated EBV at the binding sites of such transcription factors and confirmed the importance of AP-2, EBF, PU.1, and POU domain factors. Our results will provide insight into the transcriptional regulation of the major oncogene LMP1. PMID:26819314

Exclusive breastfeeding promotion by peer counsellors in sub-Saharan Africa (PROMISE-EBF): a cluster-randomised trial.

PubMed

Tylleskär, Thorkild; Jackson, Debra; Meda, Nicolas; Engebretsen, Ingunn Marie S; Chopra, Mickey; Diallo, Abdoulaye Hama; Doherty, Tanya; Ekström, Eva-Charlotte; Fadnes, Lars T; Goga, Ameena; Kankasa, Chipepo; Klungsøyr, Jørn I; Lombard, Carl; Nankabirwa, Victoria; Nankunda, Jolly K; Van de Perre, Philippe; Sanders, David; Shanmugam, Rebecca; Sommerfelt, Halvor; Wamani, Henry; Tumwine, James K

2011-07-30

Exclusive breastfeeding (EBF) is reported to be a life-saving intervention in low-income settings. The effect of breastfeeding counselling by peer counsellors was assessed in Africa. 24 communities in Burkina Faso, 24 in Uganda, and 34 in South Africa were assigned in a 1:1 ratio, by use of a computer-generated randomisation sequence, to the control or intervention clusters. In the intervention group, we scheduled one antenatal breastfeeding peer counselling visit and four post-delivery visits by trained peers. The data gathering team were masked to the intervention allocation. The primary outcomes were prevalance of EBF and diarrhoea reported by mothers for infants aged 12 weeks and 24 weeks. Country-specific prevalence ratios were adjusted for cluster effects and sites. Analysis was by intention to treat. This study is registered with ClinicalTrials.gov, number NCT00397150. 2579 mother-infant pairs were assigned to the intervention or control clusters in Burkina Faso (n=392 and n=402, respectively), Uganda (n=396 and n=369, respectively), and South Africa (n=535 and 485, respectively). The EBF prevalences based on 24-h recall at 12 weeks in the intervention and control clusters were 310 (79%) of 392 and 139 (35%) of 402, respectively, in Burkina Faso (prevalence ratio 2·29, 95% CI 1·33-3·92); 323 (82%) of 396 and 161 (44%) of 369, respectively, in Uganda (1·89, 1·70-2·11); and 56 (10%) of 535 and 30 (6%) of 485, respectively, in South Africa (1·72, 1·12-2·63). The EBF prevalences based on 7-day recall in the intervention and control clusters were 300 (77%) and 94 (23%), respectively, in Burkina Faso (3·27, 2·13-5·03); 305 (77%) and 125 (34%), respectively, in Uganda (2·30, 2·00-2·65); and 41 (8%) and 19 (4%), respectively, in South Africa (1·98, 1·30-3·02). At 24 weeks, the prevalences based on 24-h recall were 286 (73%) in the intervention cluster and 88 (22%) in the control cluster in Burkina Faso (3·33, 1·74-6·38); 232 (59%) and 57 (15%), respectively, in Uganda (3·83, 2·97-4·95); and 12 (2%) and two (<1%), respectively, in South Africa (5·70, 1·33-24·26). The prevalences based on 7-day recall were 279 (71%) in the intervention cluster and 38 (9%) in the control cluster in Burkina Faso (7·53, 4·42-12·82); 203 (51%) and 41 (11%), respectively, in Uganda (4·66, 3·35-6·49); and ten (2%) and one (<1%), respectively, in South Africa (9·83, 1·40-69·14). Diarrhoea prevalence at age 12 weeks in the intervention and control clusters was 20 (5%) and 36 (9%), respectively, in Burkina Faso (0·57, 0·27-1·22); 39 (10%) and 32 (9%), respectively, in Uganda (1·13, 0·81-1·59); and 45 (8%) and 33 (7%), respectively, in South Africa (1·16, 0·78-1·75). The prevalence at age 24 weeks in the intervention and control clusters was 26 (7%) and 32 (8%), respectively, in Burkina Faso (0·83, 0·45-1·54); 52 (13%) and 59 (16%), respectively, in Uganda (0·82, 0·58-1·15); and 54 (10%) and 33 (7%), respectively, in South Africa (1·31, 0·89-1·93). Low-intensity individual breastfeeding peer counselling is achievable and, although it does not affect the diarrhoea prevalence, can be used to effectively increase EBF prevalence in many sub-Saharan African settings. European Union Sixth Framework International Cooperation-Developing Countries, Research Council of Norway, Swedish International Development Cooperation Agency, Norwegian Programme for Development, Research and Education, South African National Research Foundation, and Rockefeller Brothers Foundation. Copyright © 2011 Elsevier Ltd. All rights reserved.

The Relationship between the Expression of Ethylene-Related Genes and Papaya Fruit Ripening Disorder Caused by Chilling Injury

PubMed Central

Zou, Yuan; Zhang, Lin; Rao, Shen; Zhu, Xiaoyang; Ye, Lanlan; Chen, Weixin; Li, Xueping

2014-01-01

Papaya (Carica papaya L.) is sensitive to low temperature and easy to be subjected to chilling injury, which causes fruit ripening disorder. This study aimed to investigate the relationship between the expression of genes related to ethylene and fruit ripening disorder caused by chilling injury. Papaya fruits were firstly stored at 7°C and 12°C for 25 and 30 days, respectively, then treated with exogenous ethylene and followed by ripening at 25°C for 5 days. Chilling injury symptoms such as pulp water soaking were observed in fruit stored at 7°C on 20 days, whereas the coloration and softening were completely blocked after 25 days, Large differences in the changes in the expression levels of twenty two genes involved in ethylene were seen during 7°C-storage with chilling injury. Those genes with altered expression could be divided into three groups: the group of genes that were up-regulated, including ACS1/2/3, EIN2, EIN3s/EIL1, CTR1/2/3, and ERF1/3/4; the group of genes that were down-regulated, including ACO3, ETR1, CTR4, EBF2, and ERF2; and the group of genes that were un-regulated, including ACO1/2, ERS, and EBF1. The results also showed that pulp firmness had a significantly positive correlation with the expression of ACS2, ACO1, CTR1/4, EIN3a/b, and EBF1/2 in fruit without chilling injury. This positive correlation was changed to negative one in fruit after storage at 7°C for 25 days with chilling injury. The coloring index displayed significantly negative correlations with the expression levels of ACS2, ACO1/2, CTR4, EIN3a/b, ERF3 in fruit without chilling injury, but these correlations were changed into the positive ones in fruit after storage at 7°C for 25 days with chilling injury. All together, these results indicate that these genes may play important roles in the abnormal softening and coloration with chilling injury in papaya. PMID:25542021

Length of time in Ghana is associated with the likelihood of exclusive breastfeeding among Liberian refugees living in Buduburam.

PubMed

Woldeghebriel, Meley; Hromi-Fiedler, Amber; Lartey, Anna; Gallego-Perez, Daniel; Sandow, Adam; Pérez-Escamilla, Rafael

2017-07-01

While literature describing immigrant's breastfeeding practices exists, especially among those living within developed countries, there is a significant gap in knowledge on how the host culture may influence the EBF behaviors of refugees, especially those living in protracted situations within sub-Saharan Africa. A cross-sectional study was conducted in the Buduburam Refugee Settlement in Ghana from July-August 2008 to explore the association between the amount of time living in Ghana and exclusive breastfeeding practices among Liberian refugees and Ghanaians in surround villages. The study included 480 women: 239 Liberians living in 12 settlement zones (in two of which Liberians and Ghanaians co-exist), 121 Ghanaians living in two settlement zones, and 120 Ghanaians living in nearby urban village of Awutu. Liberian mothers who lived in Ghana at least eight years were significantly more likely to exclusively breastfeed (OR: 1.78, 95% CI: 1.02, 3.09) compared to Ghanaian mothers living in Awutu. These findings suggest that increased time living in Buduburam improved the chances of EBF success among Liberians, perhaps as a result of unique EBF education/support opportunities offered in the settlement to Liberian refugees that were not readily available to Ghanaians. Further research to understand the "mechanisms" explaining exclusive breastfeeding differences as a function of time spent in host country is needed for improving breastfeeding support in refugee settlements and host communities. © 2016 John Wiley & Sons Ltd.

Regulating the ethylene response of a plant by modulation of F-box proteins

DOEpatents

Guo, Hongwei [Beijing, CN; Ecker, Joseph R [Carlsbad, CA

2014-01-07

The relationship between F-box proteins and proteins invovled in the ethylene response in plants is described. In particular, F-box proteins may bind to proteins involved in the ethylene response and target them for degradation by the ubiquitin/proteasome pathway. The transcription factor EIN3 is a key transcription factor mediating ethylne-regulated gene expression and morphological responses. EIN3 is degraded through a ubiquitin/proteasome pathway mediated by F-box proteins EBF1 and EBF2. The link between F-box proteins and the ethylene response is a key step in modulating or regulating the response of a plant to ethylene. Described herein are transgenic plants having an altered sensitivity to ethylene, and methods for making transgenic plant haing an althered sensitivity to ethylene by modulating the level of activity of F-box proteins. Methods of altering the ethylene response in a plant by modulating the activity or expression of an F-box protein are described. Also described are methods of identifying compounds that modulate the ethylene response in plants by modulating the level of F-box protein expression or activity.

'No sister, the breast alone is not enough for my baby' a qualitative assessment of potentials and barriers in the promotion of exclusive breastfeeding in southern Zambia.

PubMed

Fjeld, Eli; Siziya, Seter; Katepa-Bwalya, Mary; Kankasa, Chipepo; Moland, Karen Marie; Tylleskär, Thorkild

2008-11-05

Appropriate feeding practices are of fundamental importance for the survival, growth, development and health of infants and young children. The aim of the present study was to collect baseline information on current infant and young child feeding practices, attitudes and knowledge in Mazabuka, Zambia, using a qualitative approach. The study was conducted in Mazabuka, 130 km south of Lusaka in Zambia in January and February in 2005. Nine focus group discussions with mothers and a total of 18 in-depth interviews with fathers, grandmothers, health staff and traditional birth attendants were performed in both rural and urban areas. Breastfeeding was reported to be universal, the use of pre-lacteal feeds appeared to be low, colostrum was rarely discarded, and attitudes to and knowledge about exclusive breastfeeding were generally good. However, few practised exclusive breastfeeding. The barriers revealed were: (1) the perception of insufficient milk, (2) the fear of dying or becoming too sick to be able to breastfeed, (3) convention, (4) the perception of 'bad milk' and (5) lack of knowledge on the subject. The health staff and traditional birth attendants were the most important actors in transmitting knowledge about infant feeding to the mothers. Both categories appeared to have updated knowledge on child health and were well respected in the society. Fathers and grandmothers tended to be less knowledgeable on novel subjects such as exclusive breastfeeding and often showed a negative attitude towards it. At the same time they had considerable authority over mothers and children and infant feeding decisions. The rural population was in general less educated and more prone to conventional non-exclusive feeding practices. The message that exclusive breastfeeding (EBF) is beneficial for child health had reached the health workers and was taught to mothers. However, conventions and expectations from family members in this Zambian community were important barriers in preventing the message of EBF from being translated into practice. The deep-rooted beliefs that prohibit EBF need to be addressed in projects and campaigns promoting EBF.

Integrating quality improvement and translational research models to increase exclusive breastfeeding.

PubMed

Brown, Peggy A; Kaiser, Katherine Laux; Nailon, Regina E

2014-01-01

Exclusive breastfeeding (EBF), a perinatal core measure, is associated with a longer duration of breastfeeding. The purpose of this quality improvement project was to increase the percent of healthy term singleton newborns who were exclusively breastfed at an academic medical center in the Midwest. Implementation of skin-to-skin contact between mother and newborn immediately following birth resulted in an increase in the percent of healthy term singleton newborns who were EBF from 55% to 64%. © 2014 AWHONN, the Association of Women's Health, Obstetric and Neonatal Nurses.

"Frustrated," "depressed," and "devastated" pediatric trainees: US academic medical centers fail to provide adequate workplace breastfeeding support.

PubMed

Dixit, Avika; Feldman-Winter, Lori; Szucs, Kinga A

2015-05-01

Exclusive breastfeeding (EBF) is recommended until about 6 months of age. Pediatricians are at the forefront of encouraging mothers to achieve this goal, yet pediatricians who parent during their training may face substantial barriers in achieving their own breastfeeding goals. This study aimed to assess breastfeeding support available to US pediatricians in training and the effect of trainees' personal experiences on their attitude toward breastfeeding. An online survey was emailed to American Academy of Pediatrics Section on Medical Students, Residents, and Fellowship Trainees members. There were 927 respondents, of which 421 had children and 346 breastfed their children. Almost 80% agreed that 6 months is the ideal duration for EBF. One in 4 did not have access to or were not aware of a private room to express milk or breastfeed. Forty percent needed to extend the duration of their training for a longer maternity leave, with breastfeeding a factor for longer leave among 44%. One in 4 did not meet their breastfeeding duration goal, and 1 in 3 did not meet their goal for EBF. Negative emotions were common among those not meeting goals. Ninety-two percent felt that their or their partner's experience with breastfeeding affected their clinical interaction with patients' mothers. A majority of respondents cited problems with breastfeeding support during training, and many failed to meet their intended goals. Not meeting personal breastfeeding goals was associated with negative emotions and influenced how they counsel about breastfeeding as a result of personal and often negative attitudes. © The Author(s) 2015.

Commonalities and differences in infant feeding attitudes and practices in the context of HIV in sub-Saharan Africa: a metasynthesis.

PubMed

Tuthill, Emily; McGrath, Jacqueline; Young, Sera

2014-02-01

Exclusive breastfeeding (EBF) has been identified as a key intervention to promote infant health and to reduce the vertical transmission of HIV. Despite this knowledge and increased resources to promote EBF, the practice in sub-Saharan Africa (SSA) remains low among HIV+ women. Although a number of qualitative studies have been conducted throughout SSA, the influences on and consequences of infant feeding choices of HIV+ mothers' findings have not been regarded systematically. Therefore, our objective was to identify overarching themes, commonalities, and differences in infant feeding choices among qualitative studies with HIV+ mothers in SSA. Sixteen qualitative studies of infant feeding practices in the context of HIV were identified. Noblit and Hare's seven-step metasynthesis methodology was used to analyze the experiences of HIV+ women and those who provide infant feeding services/counseling. Data were available from approximately 920 participants (i.e., 750 HIV+ mothers, 109 health-care providers, and 62 family members) across 13 SSA countries from 2000 to 2011. From these data, five themes emerged within which 3-4 overarching key metaphors were identified. The consistency of key metaphors across a variety of geographic, economic, and cultural settings suggest the importance of approaching infant feeding holistically, within the context of maternal knowledge, health-care support, family resources, and cultural expectations. EBF campaigns in SSA are more likely to successfully support optimal health for infants and a safe supportive environment for their mothers when the impact of infant feeding decisions are evaluated across these themes.

Validity of Guatemalan Mother's Self-Reported Breast-Feeding Practices of 3-Month-Old Infants.

PubMed

Mazariegos, Monica; Slater, Christine; Ramirez-Zea, Manuel

2016-12-01

Breast-feeding practices (BFPs) can be assessed by interviewing the mother about current feeding practices and with a 24-hour recall. It is crucial to establish the accuracy of these methods, which are commonly used by public health decision makers to design health policies aimed at increasing exclusive breast-feeding rates. We aimed to validate 2 self-report BFP instruments using the dose-to-mother deuterium oxide turnover technique (DMDOT) as the reference method. Breast-feeding practices were assessed by interviewing the mother about current feeding practices and with a 24-hour recall in 36 Guatemalan mother-infant pairs. The validity of these instruments was assessed using DMDOT as the reference method. Both self-report instruments overestimated exclusively breast-fed (EBF) infants. Infants classified as EBF were 50% by the reported current feeding practice, 61% by the 24-hour recall, and only 36% using DMDOT. Sensitivity to detect EBF infants from the mother's self-report was 92% (95% CI: 62%-99%) while from the 24-hour recall was 100% (95% CI: 72%-100%, P < .01). However, specificity for both instruments was low, at 74% (95% CI: 51%-89%) for reported current feeding practice and at 61% (95% CI: 39%-79%) for the 24-hour recall (P < .01). Both reported current feeding practice and the 24-hour recall instruments overestimated exclusive breast-feeding. Nevertheless, the use of reported current feeding practice provided more accurate data to assess BFPs in a public health setting. Furthermore, population-based surveys should consider the overestimation of exclusive breast-feeding caused when using these BFP instruments. © The Author(s) 2016.

Interactive Effects of Early Exclusive Breastfeeding and Pre-Pregnancy Maternal Weight Status on Young Children’s BMI – A Chinese Birth Cohort

PubMed Central

Yin, Baomin; Liang, Xiong; Adair, Linda; Thompson, Amanda; Zhang, Jianduan

2015-01-01

Objectives To assess if the maternal pre-pregnancy weight status (MPWS) alters the association of early infant feeding pattern (at one and third months) with infant body mass index (BMI) in the first two years of life. Methods A cohort of 2,220 neonates were recruited in a community-based study conducted in China. Body weight and length were measured at birth, at age one and two, with BMI calculated accordingly. The BMI z-scores (BMI-Z) were computed according to the World Health Organization Growth Standard (2006). Feeding patterns were classified as exclusive breastfeeding (EBF), mixed feeding (MF), and formula feeding (FF). General linear models (GLM) were employed to estimate main and interaction effects of EBF and MPWS on children’s BMI-Z. Results No main effect of MPWS was found on child BMI-Z at ages one and two, nor the feeding patterns. An interaction between MPWS and feeding patterns was detected (p<0.05). For children who were formula fed during the first month, those who were born to overweight/obesity (OW/OB) mothers had a significantly greater BMI-Z at ages one and two, compared with those with underweight/normal weight (UW/NW) mothers. FF children had greater BMI-Z at ages one and two compared with their EBF and MF counterparts, when they were born to OW/OB mothers. Conclusions Maternal pre-pregnancy weight control and early initiation of EBF for children are essential for healthy development in children’s BMI, hence the prevention of early life obesity. PMID:26641272

[Telephone support for breastfeeding by primary care: a randomised multicentre trial].

PubMed

Balaguer Martínez, Josep Vicent; Valcarce Pérez, Inmaculada; Esquivel Ojeda, Jessica Noelia; Hernández Gil, Alicia; Martín Jiménez, María Del Pilar; Bernad Albareda, Mercè

2018-03-22

To evaluate a telephone support programme for mothers who breastfeed for the first 6 months. A randomised unmasked clinical trial was conducted in 5 urban Primary Care centres that included mothers with healthy newborns who were breastfeeding exclusively (EBF) or partially (PBF). The control group received the usual care. The intervention group also received telephone support for breastfeeding on a weekly basis for the first 2months and then every 2weeks until the sixth month. The type of breastfeeding was recorded in the usual check-up visit (1, 2, 4 and 6 months). The study included 193 patients in the intervention group, and 187 in a control group. The greatest increase in the percentage of EBF was observed at 6 months: 21.4% in the control group compared to 30.1% in the intervention group. However, in the adjusted odds ratios analysis, confidence intervals did not show statistical significance. The odds ratio at 1 month, 2 months, 4 months, and 6 months for EBF were 1.45 (0.91-2.31), 1.35 (0.87-2.08), 1.21 (0.80-1.81), and 1.58 (0.99-2.53), respectively. The odds ratio in the same age groups for any type of breastfeeding (EBF + PBF) were 1.65 (0.39-7.00), 2.08 (0.94-4.61), 1.37 (0.79-2.38), and 1.60 (0.98-2.61), respectively. Telephone intervention was not effective enough to generalise it. Copyright © 2018. Publicado por Elsevier España, S.L.U.

A Multi-step Transcriptional and Chromatin State Cascade Underlies Motor Neuron Programming from Embryonic Stem Cells.

PubMed

Velasco, Silvia; Ibrahim, Mahmoud M; Kakumanu, Akshay; Garipler, Görkem; Aydin, Begüm; Al-Sayegh, Mohamed Ahmed; Hirsekorn, Antje; Abdul-Rahman, Farah; Satija, Rahul; Ohler, Uwe; Mahony, Shaun; Mazzoni, Esteban O

2017-02-02

Direct cell programming via overexpression of transcription factors (TFs) aims to control cell fate with the degree of precision needed for clinical applications. However, the regulatory steps involved in successful terminal cell fate programming remain obscure. We have investigated the underlying mechanisms by looking at gene expression, chromatin states, and TF binding during the uniquely efficient Ngn2, Isl1, and Lhx3 motor neuron programming pathway. Our analysis reveals a highly dynamic process in which Ngn2 and the Isl1/Lhx3 pair initially engage distinct regulatory regions. Subsequently, Isl1/Lhx3 binding shifts from one set of targets to another, controlling regulatory region activity and gene expression as cell differentiation progresses. Binding of Isl1/Lhx3 to later motor neuron enhancers depends on the Ebf and Onecut TFs, which are induced by Ngn2 during the programming process. Thus, motor neuron programming is the product of two initially independent transcriptional modules that converge with a feedforward transcriptional logic. Copyright © 2017 Elsevier Inc. All rights reserved.

Dose in bone and tissue near bone-tissue interface from electron beam.

PubMed

Shiu, A S; Hogstrom, K R

1991-08-01

This work has quantitatively studied the variation of dose both within bone and in unit density tissue near bone-tissue interfaces. Dose upstream of a bone-tissue interface is increased because of an increase in the backscattered electrons from the bone. The magnitude of this effect was measured using a thin parallel-plate ionization chamber upstream of a polymethyl methacrylate (PMMA)-hard bone interface. The electron backscatter factor (EBF) increased rapidly with bone thickness until a full EBF was achieved. This occurred at approximately 3.5 mm at 2 MeV and 6 mm at 13.1 MeV. The full EBF at the interface ranged from approximately 1.018 at 13.1 MeV to 1.05 at 2 MeV. It was also observed that the EBF had a dependence on the energy spectrum at the interface. The penetration of the backscattered electrons in the upstream direction of PMMA was also measured. The dose penetration fell off rapidly in the upstream direction of the interface. Dose enhancement to unit density tissue in bone was measured for an electron beam by placing thermoluminescent dosimeters (TLDs) in a PMMA-bone-PMMA phantom. The maximum dose enhancement in bone was approximately 7% of the maximum dose in water. However, the pencil-beam algorithm of Hogstrom et al. predicted an increase of only 1%, primarily owing to the inverse-square correction. Film was also used to measure the dose enhancement in bone. The film plane was aligned either perpendicular or parallel to the central axis of the beam. The film data indicated that the maximum dose enhancement in bone was approximately 8% for the former film alignment (which was similarly predicted by the TLD measurements) and 13% for the latter film alignment. These results confirm that the X ray film is not suitable to be irritated "edge on" in an inhomogeneous phantom without making perturbation corrections resulting from the film acting as a long narrow inhomogeneous cavity within the bone. In addition, the results give the radiotherapist a basis for clinical judgment when electron beams are used to treat lesions behind bone or near bony structures. We feel these data enhance the ability to recognize the shortcomings of the current dose calculation algorithm used clinically.

A genome-wide survey on basic helix-loop-helix transcription factors in giant panda.

PubMed

Dang, Chunwang; Wang, Yong; Zhang, Debao; Yao, Qin; Chen, Keping

2011-01-01

The giant panda (Ailuropoda melanoleuca) is a critically endangered mammalian species. Studies on functions of regulatory proteins involved in developmental processes would facilitate understanding of specific behavior in giant panda. The basic helix-loop-helix (bHLH) proteins play essential roles in a wide range of developmental processes in higher organisms. bHLH family members have been identified in over 20 organisms, including fruit fly, zebrafish, mouse and human. Our present study identified 107 bHLH family members being encoded in giant panda genome. Phylogenetic analyses revealed that they belong to 44 bHLH families with 46, 25, 15, 4, 11 and 3 members in group A, B, C, D, E and F, respectively, while the remaining 3 members were assigned into "orphan". Compared to mouse, the giant panda does not encode seven bHLH proteins namely Beta3a, Mesp2, Sclerax, S-Myc, Hes5 (or Hes6), EBF4 and Orphan 1. These results provide useful background information for future studies on structure and function of bHLH proteins in the regulation of giant panda development.

The Relationship of the Administration of Intrapartum Synthetic Oxytocin and Breastfeeding Initiation and Duration Rates.

PubMed

Fernández-Cañadas Morillo, Aurora; Marín Gabriel, Miguel A; Olza Fernández, Ibone; Martínez Rodríguez, Begoña; Durán Duque, Modesto; Malalana Martínez, Ana M; Gonzalez Armengod, Carmen; Pérez Riveiro, Pilar; García Murillo, Lourdes

2017-03-01

The consequences that intrapartum administration of hormones can have on breastfeeding are unclear. The aim of the study is to determine if synthetic intrapartum oxytocin, used routinely for induction/stimulation, has a relationship to initiation/duration of breastfeeding. We conducted a cohort study that was carried out in a tertiary university hospital distinguished by WHO-UNICEF as a BFHI (Baby-Friendly Hospital Initiative). A group of 53 mother and newborn dyads who had been exposed to intrapartum synthetic oxytocin were compared with 45 nonexposed dyads. A breastfeeding questionnaire was administered by a midwife blind to patient group through phone calls 3 and 6 months after delivery. No statistically significant differences were observed between the two groups in the rates of mothers exclusively breastfeeding (EBF) or nonexclusively breastfeeding. The percentage of those who were EBF when discharged was 97.3% in the oxytocin-nonexposed group and 87.1% in the oxytocin-exposed group (p = 0.14). At 3 months, the group rates of exclusive breastfeeding were 72.5% in the nonoxytocin-exposed group versus 65.9% in the oxytocin-exposed group (p = 0.71). At 6 months, rates of breastfeeding were 31.4% versus 27.9% (p = 0.53) in the oxytocin-nonexposed and oxytocin-exposed groups, respectively. In this study, no statistically significant effect of intrapartum synthetic oxytocin administration was observed pertaining to the initiation or duration of breastfeeding.

Lentiviral Vector Induced Insertional Haploinsufficiency of Ebf1 Causes Murine Leukemia

PubMed Central

Heckl, Dirk; Schwarzer, Adrian; Haemmerle, Reinhard; Steinemann, Doris; Rudolph, Cornelia; Skawran, Britta; Knoess, Sabine; Krause, Johanna; Li, Zhixiong; Schlegelberger, Brigitte; Baum, Christopher; Modlich, Ute

2012-01-01

Integrating vectors developed on the basis of various retroviruses have demonstrated therapeutic potential following genetic modification of long-lived hematopoietic stem and progenitor cells. Lentiviral vectors (LV) are assumed to circumvent genotoxic events previously observed with γ-retroviral vectors, due to their integration bias to transcription units in comparison to the γ-retroviral preference for promoter regions and CpG islands. However, recently several studies have revealed the potential for gene activation by LV insertions. Here, we report a murine acute B-lymphoblastic leukemia (B-ALL) triggered by insertional gene inactivation. LV integration occurred into the 8th intron of Ebf1, a major regulator of B-lymphopoiesis. Various aberrant splice variants could be detected that involved splice donor and acceptor sites of the lentiviral construct, inducing downregulation of Ebf1 full-length message. The transcriptome signature was compatible with loss of this major determinant of B-cell differentiation, with partial acquisition of myeloid markers, including Csf1r (macrophage colony-stimulating factor (M-CSF) receptor). This was accompanied by receptor phosphorylation and STAT5 activation, both most likely contributing to leukemic progression. Our results highlight the risk of intragenic vector integration to initiate leukemia by inducing haploinsufficiency of a tumor suppressor gene. We propose to address this risk in future vector design. PMID:22472950

Alternative hospital gift bags and breastfeeding exclusivity.

PubMed

Bai, Yeon; Wunderlich, Shahla M; Kashdan, Rickie

2013-01-01

The type of gift bags given to new mothers at the time of discharge from the hospital can influence their confidence in breastfeeding. Most hospitals in the US continue to distribute commercial gift bags containing formula samples despite the reported negative influence of commercial bags on the duration of breastfeeding. This study compared breastfeeding outcomes in women receiving three different kinds of gift bags at discharge. A prospective intervention study was conducted during 2009-2010 in New Jersey. Three breastfeeding cohorts were recruited and assigned to three groups: COMMERCIAL received discharge bags containing formula samples, BF-INFO received breastfeeding information and supplies, and PUMP received breastfeeding information/supplies plus a manual breast pump. Follow-up contacts were at 2, 4, and 12 postpartum weeks to determine breastfeeding outcome. The mean durations of exclusive (EBF) and partial breastfeeding were compared between groups using ANOVA. A total of 386 participants completed the study. The mean EBF duration (weeks) in the PUMP (n = 138, 8.28 ± 4.86) and BF-INFO (n = 121, 7.87 ± 4.63) were significantly longer (P < 0.01) than COMMERCIAL (n = 127, 6.12 ± 4.49). The rate of EBF through 12 weeks in PUMP was most consistent. The mean duration of partial breastfeeding showed similar results: significantly longer in PUMP and BF-INFO than COMMERCIAL (P < 0.01).

Breastfeeding indicators among a nationally representative multi-ethnic sample of New Zealand children.

PubMed

Castro, Teresa; Grant, Cameron; Wall, Clare; Welch, Michaela; Marks, Emma; Fleming, Courtney; Teixeira, Juliana; Bandara, Dinusha; Berry, Sarah; Morton, Susan

2017-12-01

To describe breastfeeding initiation and duration, and demographic associations with breastfeeding duration within a representative sample of New Zealand infants. In 6,685 singletons enrolled in the Growing Up in New Zealand cohort we described breastfeeding initiation (96%), any (94%) and exclusive (93%) breastfeeding (EBF) duration. We used adjusted relative risk (RR) and 95% confidence intervals (CI) to describe associations with breastfeeding duration. Breastfeeding initiation occurred for 97%. Sixteen percent were EBF to age six months and 13% were breastfed to age 24 months. Exclusive breastfeeding for ≥4 months was less likely for children of mothers of Māori (RR=0.80, 95% CI 0.73-0.87), Pacific (0.90, 95% CI 0.83-0.98) or Asian (0.80, 95% CI 0.74-0.86) ethnicity. Children of mothers aged 20-29 years (1.24, 95% CI 1.04-1.49); ≥30 years (1.36, 95% CI 1.14-1); with a tertiary education (1.14, 95% CI 1.08-1.21); or planned pregnancy (1.14, 95% CI 1.08-1.21); and children with older siblings (RR=1.31, 95% CI 1.17-1.47) were more likely to be exclusively breastfed for ≥4 months. Children were more likely to be breastfed ≥6 months if their mother was aged 20-29 (1.26, 95% CI 1.10-1.45) or ≥30 years (1.40, 95% CI 1.22-1.61), had a tertiary education (1.11, 95% CI 1.06-1.59) or planned pregnancy (1.11, 95% CI 1.06-1.15), or if they had older siblings (1.04, 95% CI 1.00-1.08). In New Zealand, most children are initially breastfed, however a large proportion did not receive the recommended duration of any or exclusive breastfeeding. Maternal age, education, parity and pregnancy planning identify children at risk of shorter duration of breastfeeding and EBF, and maternal ethnicity identifies children at risk of shorter EBF duration.

Environmental controls on seasonal ecosystem evapotranspiration/potential evapotranspiration ratio as determined by the global eddy flux measurements

NASA Astrophysics Data System (ADS)

Liu, Chunwei; Sun, Ge; McNulty, Steven G.; Noormets, Asko; Fang, Yuan

2017-01-01

The evapotranspiration / potential evapotranspiration (AET / PET) ratio is traditionally termed as the crop coefficient (Kc) and has been generally used as ecosystem evaporative stress index. In the current hydrology literature, Kc has been widely used as a parameter to estimate crop water demand by water managers but has not been well examined for other types of ecosystems such as forests and other perennial vegetation. Understanding the seasonal dynamics of this variable for all ecosystems is important for projecting the ecohydrological responses to climate change and accurately quantifying water use at watershed to global scales. This study aimed at deriving monthly Kc for multiple vegetation cover types and understanding its environmental controls by analyzing the accumulated global eddy flux (FLUXNET) data. We examined monthly Kc data for seven vegetation covers, including open shrubland (OS), cropland (CRO), grassland (GRA), deciduous broad leaf forest (DBF), evergreen needle leaf forest (ENF), evergreen broad leaf forest (EBF), and mixed forest (MF), across 81 sites. We found that, except for evergreen forests (EBF and ENF), Kc values had large seasonal variation across all land covers. The spatial variability of Kc was well explained by latitude, suggesting site factors are a major control on Kc. Seasonally, Kc increased significantly with precipitation in the summer months, except in EBF. Moreover, leaf area index (LAI) significantly influenced monthly Kc in all land covers, except in EBF. During the peak growing season, forests had the highest Kc values, while croplands (CRO) had the lowest. We developed a series of multivariate linear monthly regression models for Kc by land cover type and season using LAI, site latitude, and monthly precipitation as independent variables. The Kc models are useful for understanding water stress in different ecosystems under climate change and variability as well as for estimating seasonal ET for large areas with mixed land covers.

The empirical Bayes estimators of fine-scale population structure in high gene flow species.

PubMed

Kitada, Shuichi; Nakamichi, Reiichiro; Kishino, Hirohisa

2017-11-01

An empirical Bayes (EB) pairwise F ST estimator was previously introduced and evaluated for its performance by numerical simulation. In this study, we conducted coalescent simulations and generated genetic population structure mechanistically, and compared the performance of the EBF ST with Nei's G ST , Nei and Chesser's bias-corrected G ST (G ST_NC ), Weir and Cockerham's θ (θ WC ) and θ with finite sample correction (θ WC_F ). We also introduced EB estimators for Hedrick' G' ST and Jost' D. We applied these estimators to publicly available SNP genotypes of Atlantic herring. We also examined the power to detect the environmental factors causing the population structure. Our coalescent simulations revealed that the finite sample correction of θ WC is necessary to assess population structure using pairwise F ST values. For microsatellite markers, EBF ST performed the best among the present estimators regarding both bias and precision under high gene flow scenarios (FST≤0.032). For 300 SNPs, EBF ST had the highest precision in all cases, but the bias was negative and greater than those for G ST_NC and θ WC_F in all cases. G ST_NC and θ WC_F performed very similarly at all levels of F ST . As the number of loci increased up to 10 000, the precision of G ST_NC and θ WC_F became slightly better than for EBF ST for cases with FST≥0.004, even though the size of the bias remained constant. The EB estimators described the fine-scale population structure of the herring and revealed that ~56% of the genetic differentiation was caused by sea surface temperature and salinity. The R package finepop for implementing all estimators used here is available on CRAN. © 2017 The Authors. Molecular Ecology Resources Published by John Wiley & Sons Ltd.

Environmental controls on seasonal ecosystem evapotranspiration/potential evapotranspiration ratio as determined by the global eddy flux measurements

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Chunwei; Sun, Ge; McNulty, Steven G.

The evapotranspiration / potential evapotranspiration (AET / PET) ratio is traditionally termed as the crop coefficient ( K c) and has been generally used as ecosystem evaporative stress index. In the current hydrology literature, K c has been widely used as a parameter to estimate crop water demand by water managers but has not been well examined for other types of ecosystems such as forests and other perennial vegetation. Understanding the seasonal dynamics of this variable for all ecosystems is important for projecting the ecohydrological responses to climate change and accurately quantifying water use at watershed to global scales. Thismore » study aimed at deriving monthly K c for multiple vegetation cover types and understanding its environmental controls by analyzing the accumulated global eddy flux (FLUXNET) data. We examined monthly K c data for seven vegetation covers, including open shrubland (OS), cropland (CRO), grassland (GRA), deciduous broad leaf forest (DBF), evergreen needle leaf forest (ENF), evergreen broad leaf forest (EBF), and mixed forest (MF), across 81 sites. We found that, except for evergreen forests (EBF and ENF), K c values had large seasonal variation across all land covers. The spatial variability of K c was well explained by latitude, suggesting site factors are a major control on K c. Seasonally, K c increased significantly with precipitation in the summer months, except in EBF. Moreover, leaf area index (LAI) significantly influenced monthly K c in all land covers, except in EBF. During the peak growing season, forests had the highest K c values, while croplands (CRO) had the lowest. We developed a series of multivariate linear monthly regression models for K c by land cover type and season using LAI, site latitude, and monthly precipitation as independent variables. Here, the K c models are useful for understanding water stress in different ecosystems under climate change and variability as well as for estimating seasonal ET for large areas with mixed land covers.« less

Environmental controls on seasonal ecosystem evapotranspiration/potential evapotranspiration ratio as determined by the global eddy flux measurements

DOE PAGES

Liu, Chunwei; Sun, Ge; McNulty, Steven G.; ...

2017-01-18

The evapotranspiration / potential evapotranspiration (AET / PET) ratio is traditionally termed as the crop coefficient ( K c) and has been generally used as ecosystem evaporative stress index. In the current hydrology literature, K c has been widely used as a parameter to estimate crop water demand by water managers but has not been well examined for other types of ecosystems such as forests and other perennial vegetation. Understanding the seasonal dynamics of this variable for all ecosystems is important for projecting the ecohydrological responses to climate change and accurately quantifying water use at watershed to global scales. Thismore » study aimed at deriving monthly K c for multiple vegetation cover types and understanding its environmental controls by analyzing the accumulated global eddy flux (FLUXNET) data. We examined monthly K c data for seven vegetation covers, including open shrubland (OS), cropland (CRO), grassland (GRA), deciduous broad leaf forest (DBF), evergreen needle leaf forest (ENF), evergreen broad leaf forest (EBF), and mixed forest (MF), across 81 sites. We found that, except for evergreen forests (EBF and ENF), K c values had large seasonal variation across all land covers. The spatial variability of K c was well explained by latitude, suggesting site factors are a major control on K c. Seasonally, K c increased significantly with precipitation in the summer months, except in EBF. Moreover, leaf area index (LAI) significantly influenced monthly K c in all land covers, except in EBF. During the peak growing season, forests had the highest K c values, while croplands (CRO) had the lowest. We developed a series of multivariate linear monthly regression models for K c by land cover type and season using LAI, site latitude, and monthly precipitation as independent variables. Here, the K c models are useful for understanding water stress in different ecosystems under climate change and variability as well as for estimating seasonal ET for large areas with mixed land covers.« less

Factors influencing the practice of exclusive breastfeeding among nursing mothers in a peri-urban district of Ghana.

PubMed

Mensah, Kofi Akohene; Acheampong, Enoch; Anokye, Francis Owusu; Okyere, Paul; Appiah-Brempong, Emmanuel; Adjei, Rose Odotei

2017-09-07

Exclusive breastfeeding (EBF) is one of the optimal infant and young child feeding practices. Globally, <40% of infants under 6 months of age are exclusively breastfed. In Ghana, 63% of children <6 months are exclusively breastfed which is far less than the 100% recommended by the United Nation Children Emergency Fund. This study was carried out to find out the factors that influence the practice of exclusive breastfeeding in the district. A cross-sectional quantitative study was conducted using structured questionnaires. A convenience sampling technique was employed to select 380 nursing mothers who attended postnatal care at the postnatal clinic in all the 13 health facilities with child welfare clinics (both public and private) and were available on the day of data collection. Data were analysed using frequency and CHISQ tables. There was a significant association between socio-demographic characteristics of mothers such as age (p = 0.129), religion (p = 0.035) type of employment (p = 0.005) and the practice of exclusive breastfeeding. Again, there was significant relationship between mothers' knowledge on EBF in terms of sources of information about EBF (p = 0.000), steps taken by mothers who perceived not to have breast milk (p = 0.000), some medical conditions of nursing mothers (p = 0.000) and the practice of EBF. Most nursing mothers use infant formula feeds as either supplement or substitute for breast milk based on their perception that breast milk may not be sufficient for the babies despite the high cost of these artificial milk. This puts the babies at a higher risk of compromised health and malnutrition which has the potential of increasing infant mortality. Most mothers are not practicing exclusive breastfeeding because their spouses and family members do not allow them.

Mobile Applications for Participation at the Shopping Mall: Content Analysis and Usability for Persons with Physical Disabilities and Communication or Cognitive Limitations

PubMed Central

Auger, Claudine; Leduc, Emilie; Labbé, Delphine; Guay, Cassioppée; Fillion, Brigitte; Bottari, Carolina; Swaine, Bonnie

2014-01-01

The aim of this exploratory study was to determine the important features in content and usability of existing mobile applications evaluating environmental barriers and facilitators (EBF) to participation for persons with physical disabilities presenting mild communication or cognitive limitations. A rigorous process based on a user-centered design approach led to the identification of two relevant mobile applications to evaluate the EBF. An accessibility expert, the research team as well as five users then tested the mobile applications in a shopping mall. A thematic content analysis of the research team’s and users’ comments established 10 categories of key features that adequately respond to the needs of the clientele targeted in this study. In terms of content, granularity and contextualization of the information provided were considered important. With respect to usability, relevant features were place finding, rating system, presentation of results, compatibility, user-friendliness, aesthetics, credibility of the information as well as connectivity/interactiveness. The research team and the users agreed on some aspects such as aesthetics, but had different perspectives on features such as the rating system or the connectivity/interactiveness of the application. The users proposed new features suggesting that the existing mobile applications did not correspond to all their needs. PMID:25513999

Mobile applications for participation at the shopping mall: content analysis and usability for persons with physical disabilities and communication or cognitive limitations.

PubMed

Auger, Claudine; Leduc, Emilie; Labbé, Delphine; Guay, Cassioppée; Fillion, Brigitte; Bottari, Carolina; Swaine, Bonnie

2014-12-01

The aim of this exploratory study was to determine the important features in content and usability of existing mobile applications evaluating environmental barriers and facilitators (EBF) to participation for persons with physical disabilities presenting mild communication or cognitive limitations. A rigorous process based on a user-centered design approach led to the identification of two relevant mobile applications to evaluate the EBF. An accessibility expert, the research team as well as five users then tested the mobile applications in a shopping mall. A thematic content analysis of the research team's and users' comments established 10 categories of key features that adequately respond to the needs of the clientele targeted in this study. In terms of content, granularity and contextualization of the information provided were considered important. With respect to usability, relevant features were place finding, rating system, presentation of results, compatibility, user-friendliness, aesthetics, credibility of the information as well as connectivity/interactiveness. The research team and the users agreed on some aspects such as aesthetics, but had different perspectives on features such as the rating system or the connectivity/interactiveness of the application. The users proposed new features suggesting that the existing mobile applications did not correspond to all their needs.

Non-Intrusive Optical Diagnostic Methods for Flowfield Characterization

NASA Technical Reports Server (NTRS)

Tabibi, Bagher M.; Terrell, Charles A.; Spraggins, Darrell; Lee, Ja. H.; Weinstein, Leonard M.

1997-01-01

Non-intrusive optical diagnostic techniques such as Electron Beam Fluorescence (EBF), Laser-Induced Fluorescence (LIF), and Focusing Schlieren (FS) have been setup for high-speed flow characterization and large flowfield visualization, respectively. Fluorescence emission from the First Negative band of N2(+) with the (0,0) vibration transition (at lambda =391.44 nm) was obtained using the EBF technique and a quenching rate of N2(+)* molecules by argon gas was reported. A very high sensitivity FS system was built and applied in the High-Speed Flow Generator (HFG) at NASA LaRC. A LIF system is available at the Advanced Propulsion Laboratory (APL) on campus and a plume exhaust velocity measurement, measuring the Doppler shift from lambda = 728.7 nm of argon gas, is under way.

Study of gamma ray energy absorption and exposure buildup factors for ferrites by geometric progression fitting method

NASA Astrophysics Data System (ADS)

Raut, S. D.; Awasarmol, V. V.; Shaikh, S. F.; Ghule, B. G.; Ekar, S. U.; Mane, R. S.; Pawar, P. P.

2018-04-01

The gamma ray energy absorption and exposure buildup factors (EABF and EBF) were calculated for ferrites such as cobalt ferrite (CoFe2O4), zinc ferrite (ZnFe2O4), nickel ferrite (NiFe2O4) and magnesium ferrite (MgFe2O4) using five parametric geometric progression (G-P fitting) formula in the energy range 0.015-15.00 MeV up to the penetration depth 40 mean free path (mfp). The obtained data of absorption and exposure buildup factors have been studied as a function of incident photon energy and penetration depth. The obtained EABF and EBF data are useful for radiation dosimetry and radiation therapy.

Infant and young child feeding indicators across nine East and Southeast Asian countries: an analysis of National Survey Data 2000-2005.

PubMed

Dibley, Michael J; Senarath, Upul; Agho, Kingsley E

2010-09-01

To compare infant and young child feeding practices in children aged 0-23 months across nine East and Southeast Asian countries. Secondary analyses of cross-sectional data from available Demographic and Health Surveys (DHS; Indonesia, Philippines, Timor-Leste, Cambodia and Vietnam), Multiple Indicator Country Surveys (Lao People's Democratic Republic (Lao PDR) and Myanmar) and national nutrition surveys (Democratic People's Republic of Korea (DPR Korea) and Mongolia) conducted between 2000 and 2005. Seven countries from Southeast Asia and two from East Asia. Children aged 0-23 months with samples ranging from 826 to 5610 for DHS, and from 477 to 5860 for non-DHS data. More than 93 % of infants were ever breast-fed, and over 75 % were currently breast-fed except in the Philippines. Timely initiation of breast-feeding varied from 32 % in Indonesia to 46 % in Timor-Leste. Exclusive breast-feeding (EBF) rate in infants under 6 months of age ranged from 11 % in Myanmar to 60 % in Cambodia. EBF rates were also low in Vietnam (15.5 %) and Lao PDR (23 %), and varied between 30 % and 40 % in Indonesia, Philippines and Timor-Leste. The proportion of infants under 6 months of age who were given breast milk with non-milk liquids was high except in Indonesia and Timor-Leste. Bottle-feeding rates were lower in DPR Korea (3 %), Lao PDR (6 %) and Myanmar (6 %) and higher in the Philippines (49 %) and Mongolia (31 %). Timely complementary-feeding rate varied widely across countries (6-99 %). All the countries studied should make greater efforts to improve timely initiation of breast-feeding and EBF for 6 months. Measures should be taken to reduce high bottle-feeding rate in the Philippines, Mongolia, Indonesia and Vietnam, and improve complementary-feeding rate in Lao PDR, Myanmar, DPR Korea and Philippines.

Determinants of cessation of exclusive breastfeeding in Ankesha Guagusa Woreda, Awi Zone, Northwest Ethiopia: a cross-sectional study.

PubMed

Yeneabat, Tebikew; Belachew, Tefera; Haile, Muluneh

2014-08-09

Exclusive breast-feeding (EBF) is the practice of feeding only breast milk (including expressed breast milk) during the first six months and no other liquids and solid foods except medications. The time to cessation of exclusive breast-feeding, however, is different in different countries depending on different factors. Studies showed the risk of diarrhea morbidity and mortality is higher among none exclusive breast-feeding infants, common during starting other foods. However, there is no study that evaluated the time to cessation of exclusive breast-feeding in the study area. The aim of this study was to show time to cessation of EBF and its predictors among mothers of index infants less than twelve months old. We conducted a community-based cross-sectional study from February 13 to March 3, 2012 using both quantitative and qualitative methods. This study included a total of 592 mothers of index infant using multi-stage sampling method. Data were collected by using interviewer administered structured questionnaire. Bivariate and multivariate Cox regression analyses were performed. Cessation of exclusive breast-feeding occurred in 392 (69.63%) cases. Among these, 224 (57.1%) happened before six months, while 145 (37.0%) and 23 (5.9%) occurred at six months and after six months of age of the index infant respectively. The median time for infants to stay on exclusive breast-feeding was 6.36 months in rural and 5.13 months in urban, and this difference was statistically significant on a Log rank (Cox-mantel) test. Maternal and paternal occupation, place of residence, postnatal counseling on exclusive breast-feeding, mode of delivery, and birth order of the index infant were significant predictors of cessation of exclusive breast-feeding. Providing postnatal care counseling on EBF, routine follow-up and support of those mothers having infants stressing for working mothers can bring about implementation of national strategy on infant and young child feeding.

Comparison of tulathromycin and tilmicosin on the prevalence and severity of bovine respiratory disease in feedlot cattle in association with feedlot performance, carcass characteristics, and economic factors.

PubMed

Tennant, T C; Ives, S E; Harper, L B; Renter, D G; Lawrence, T E

2014-11-01

The objectives of this study were to 1) quantify effects of metaphylactic treatment for bovine respiratory disease (BRD) on growth performance, carcass characteristics, and lung lesion prevalence and severity; 2) evaluate the association of lung lesion prevalence and severity with carcass characteristics; and 3) evaluate effects of therapeutic treatment on carcass characteristics and lung lesion prevalence and severity. The study was conducted at a commercial feedlot in the Texas Panhandle in which steers (n = 2,336) initially weighing 312.1 ± 9.6 kg were sourced from auction markets and allocated in a randomized complete block design to 1 of 3 treatments (no metaphylactic [no antimicrobial drug {ND}] treatment, tilmicosin at 10 mg/kg BW [TIL], and tulathromycin at 2.5 mg/kg BW [TUL]). Lungs of all steers were evaluated during harvest to assess presence and severity of pneumonic lesions in the anteroventral lobes and the presence and severity of pleural adherences. Compared to the ND treatment, steers treated via metaphylactic therapy had greater (P < 0.05) metaphylactic cost, ADG, shrunk final BW, dressed carcass yield, HCW, 12th rib fat, calculated empty body fat (EBF), and gross revenue, concurrent with reduced (P < 0.05) BRD treatment costs and financial losses from BRD death and railed cattle, cumulatively resulting in greater financial returns. Lung lesions were present in 64.3% of lungs and were distributed similarly between metaphylactic treatments (63.9%) and ND (65.1%) cattle. Steers with advanced lung lesions present at harvest were associated with reduced (P < 0.05) HCW, KPH, 12th rib fat, calculated yield grades, marbling scores, and calculated EBF as compared to steers without lung lesions. Steers pulled for BRD had increased (P < 0.01) incidence of advanced lung lesions, mortality, and railers with decreased (P < 0.05) HCW, 12th rib fat, KPH, marbling score, calculated EBF, and percentage choice carcasses when compared to non-BRD event steers. From the results of this study, controlling BRD through the use of metaphylactic treatments on arrival in heavier cattle improved financial returns primarily driven by reductions in cost of death loss and railers.

Investigation of the adhesion properties of direct 3D printing of polymers and nanocomposites on textiles: Effect of FDM printing process parameters

NASA Astrophysics Data System (ADS)

Hashemi Sanatgar, Razieh; Campagne, Christine; Nierstrasz, Vincent

2017-05-01

In this paper, 3D printing as a novel printing process was considered for deposition of polymers on synthetic fabrics to introduce more flexible, resource-efficient and cost effective textile functionalization processes than conventional printing process like screen and inkjet printing. The aim is to develop an integrated or tailored production process for smart and functional textiles which avoid unnecessary use of water, energy, chemicals and minimize the waste to improve ecological footprint and productivity. Adhesion of polymer and nanocomposite layers which were 3D printed directly onto the textile fabrics using fused deposition modeling (FDM) technique was investigated. Different variables which may affect the adhesion properties including 3D printing process parameters, fabric type and filler type incorporated in polymer were considered. A rectangular shape according to the peeling standard was designed as 3D computer-aided design (CAD) to find out the effect of the different variables. The polymers were printed in different series of experimental design: nylon on polyamide 66 (PA66) fabrics, polylactic acid (PLA) on PA66 fabric, PLA on PLA fabric, and finally nanosize carbon black/PLA (CB/PLA) and multi-wall carbon nanotubes/PLA (CNT/PLA) nanocomposites on PLA fabrics. The adhesion forces were quantified using the innovative sample preparing method combining with the peeling standard method. Results showed that different variables of 3D printing process like extruder temperature, platform temperature and printing speed can have significant effect on adhesion force of polymers to fabrics while direct 3D printing. A model was proposed specifically for deposition of a commercial 3D printer Nylon filament on PA66 fabrics. In the following, among the printed polymers, PLA and its composites had high adhesion force to PLA fabrics.

Maternal and health care workers' perceptions of the effects of exclusive breastfeeding by HIV positive mothers on maternal and infant health in Blantyre, Malawi.

PubMed

Kafulafula, Ursula K; Hutchinson, Mary K; Gennaro, Susan; Guttmacher, Sally

2014-07-25

HIV-positive mothers are likely to exclusively breastfeed if they perceive exclusive breastfeeding (EBF) beneficial to them and their infants. Nevertheless, very little is known in Malawi about HIV-positive mothers' perceptions regarding EBF. In order to effectively promote EBF among these mothers, it is important to first understand their perceptions on benefits of exclusive breastfeeding. This study therefore, explored maternal and health care workers' perceptions of the effects of exclusive breastfeeding on HIV-positive mothers' health and that of their infants. This was a qualitative study within a larger project. Face-to-face in-depth interviews and focus group discussions using a semi- structured interview and focus group guide were conducted. Sixteen HIV-positive breastfeeding mothers, between 18 and 35 years old, were interviewed and data saturation was achieved. Two focus group discussions (FGDs) comprising of five and six adult women of unknown HIV status who were personal assistants to maternity patients, and one FGD with five nurse-midwives working in the maternity wards of Queen Elizabeth Central Hospital in Blantyre, Malawi, were also conducted. Thematic content data analysis was utilized. The study revealed more positive than negative perceived effects of exclusive breastfeeding. However, the fear of transmitting HIV to infants through breast milk featured strongly in the study participants' reports including those of the nurse-midwives. Only one nurse-midwife and a few HIV-positive mothers believed that EBF prevents mother-to-child transmission of HIV. Furthermore, participants, especially the HIV-positive mothers felt that exclusive breastfeeding leads to maternal ill- health and would accelerate their progression to full blown AIDS. While most participants considered exclusive breastfeeding as an important component of the wellbeing of their infants' health, they did not share the worldwide acknowledged benefits of exclusive breastfeeding in the prevention of mother-to-child transmission (PMTCT) of HIV. These results suggest a need for more breastfeeding education for all mothers, communities and nurse-midwives involved in breastfeeding counseling in the context of HIV infection. Maternal wellbeing promotion activities such as nutrition supplementation need to be included in all PMTCT of HIV programs.

Fabrication Process for Cantilever Beam Micromechanical Switches

DTIC Science & Technology

1993-08-01

Beam Design ................................................................... 13 B. Chemistry and Materials Used in Cantilever Beam Process...7 3. Photomask levels and composite...pp 410-413. 5 2. Cantilever Beam Fabrication Process The beam fabrication process incorporates four different photomasking levels with 62 processing

Severe physical violence between intimate partners during pregnancy: a risk factor for early cessation of exclusive breast-feeding.

PubMed

Moraes, Claudia L; de Oliveira, Alessandra S D; Reichenheim, Michael E; Lobato, Gustavo

2011-12-01

To investigate the role of severe physical violence during pregnancy (SPVP) between intimate partners in early cessation of exclusive breast-feeding (EBF). A health services survey. The revised Conflict Tactics Scale was used to characterize SPVP; premature breast-feeding cessation was identified using a current status data approach, which was based on the information reported from food recall during the preceding 7 d. The cumulative hazard function was estimated by complementary log-log transformation models, which allowed the ensuing estimation of early breast-feeding cessation rates in different age groups and the ratio of rates of weaning between women exposed and not exposed to violence. Five large public primary health-care facilities of Rio de Janeiro, Brazil. The sample comprised 811 randomly selected mothers of children under 5 months of age who were waiting to be consulted. SPVP is an independent risk factor of cessation of EBF since, after controlling for socio-economic, demographic, reproductive and lifestyle variables, women exposed to violence presented an incidence density that was 31% higher than those who were not exposed (hazard ratio = 1·30, 95% CI 1·01, 1·69). The findings corroborate the hypothesis that SPVP is an important risk factor for EBF. This indicates the need for incentives to adequately train health-care personnel in dealing with lactating women in order to gain a broader view of breast-feeding beyond the biological aspects of lactation, including the maternal psychological dimension.

Fabrication of single domain GdBCO bulk superconductors by a new modified TSIG technique

NASA Astrophysics Data System (ADS)

Yang, W. M.; Zhi, X.; Chen, S. L.; Wang, M.; Li, J. W.; Ma, J.; Chao, X. X.

2014-01-01

Single domain GdBCO bulk superconductors have been fabricated with new and traditional solid phases by a top seeded infiltration and growth (TSIG) process technique. In the conventional TSIG process, three types of powders, such as Gd2BaCuO5, GdBa2Cu3O7-x and Ba3Cu5O8, must be prepared, but in our new modified TSIG technique, only BaCuO2 powders are required during the fabrication of the single domain GdBCO bulk superconductors. The solid phase used in the conventional process is Gd2BaCuO5 instead of the solid phase (Gd2O3 + BaCuO2) utilized in the new process. The liquid phase used in the conventional process is a mixture of (GdBa2Cu3O7-x + Ba3Cu5O8), and the liquid phase in the new process is a mixture of (Gd2O3 + 10BaCuO2 + 6CuO). Single domain GdBCO bulk superconductors have been fabricated with the new solid and liquid phases. The levitation force of the GdBCO bulk samples fabricated by the new solid phase is 28 N, which is slightly higher than that of the samples fabricated using the conventional solid phases (26 N). The microstructure and the levitation force of the samples indicate that this new method can greatly simplify the fabrication process, introduce nanometer-sized flux centers, improve the levitation force and working efficiency, and greatly reduce the cost of fabrication of single domain GdBCO bulk superconductors by the TSIG process.

Effect of women’s groups and volunteer peer counselling on rates of mortality, morbidity, and health behaviours in mothers and children in rural Malawi (MaiMwana): a factorial, cluster-randomised controlled trial

PubMed Central

Lewycka, Sonia; Mwansambo, Charles; Rosato, Mikey; Kazembe, Peter; Phiri, Tambosi; Mganga, Andrew; Chapota, Hilda; Malamba, Florida; Kainja, Esther; Newell, Marie-Louise; Greco, Giulia; Pulkki-Brännström, Anni-Maria; Skordis-Worrall, Jolene; Vergnano, Stefania; Osrin, David; Costello, Anthony

2013-01-01

Summary Background Women’s groups and health education by peer counsellors can improve the health of mothers and children. We assessed their effects on mortality and breastfeeding rates in rural Malawi. Methods We did a 2×2 factorial, cluster-randomised trial in 185 888 people in Mchinji district. 48 equal-sized clusters were randomly allocated to four groups with a computer-generated number sequence. 24 facilitators guided groups through a community action cycle to tackle maternal and child health problems. 72 trained volunteer peer counsellors made home visits at five timepoints during pregnancy and after birth to support breastfeeding and infant care. Primary outcomes for the women’s group intervention were maternal, perinatal, neonatal, and infant mortality rates (MMR, PMR, NMR, and IMR, respectively); and for the peer counselling were IMR and exclusive breastfeeding (EBF) rates. Analysis was by intention to treat. The trial is registered as ISRCTN06477126. Findings We monitored outcomes of 26 262 births between 2005 and 2009. In a factorial model adjusted only for clustering and the volunteer peer counselling intervention, in women’s group areas, for years 2 and 3, we noted non-significant decreases in NMR (odds ratio 0·93, 0·64–1·35) and MMR (0·54, 0·28–1·04). After adjustment for parity, socioeconomic quintile, and baseline measures, effects were larger for NMR (0·85, 0·59–1·22) and MMR (0·48, 0·26–0·91). Because of the interaction between the two interventions, a stratified analysis was done. For women’s groups, in adjusted analyses, MMR fell by 74% (0·26, 0·10–0·70), and NMR by 41% (0·59, 0·40–0·86) in areas with no peer counsellors, but there was no effect in areas with counsellors (1·09, 0·40–2·98, and 1·38, 0·75–2·54). Factorial analysis for the peer counselling intervention for years 1–3 showed a fall in IMR of 18% (0·82, 0·67–1·00) and an improvement in EBF rates (2·42, 1·48–3·96). The results of the stratified, adjusted analysis showed a 36% reduction in IMR (0·64, 0·48–0·85) but no effect on EBF (1·18, 0·63–2·25) in areas without women’s groups, and in areas with women’s groups there was no effect on IMR (1·05, 0·82–1·36) and an increase in EBF (5·02, 2·67–9·44) . The cost of women’s groups was US$114 per year of life lost (YLL) averted and that of peer counsellors was $33 per YLL averted, using stratified data from single intervention comparisons. Interpretation Community mobilisation through women’s groups and volunteer peer counsellor health education are methods to improve maternal and child health outcomes in poor rural populations in Africa. Funding Saving Newborn Lives, UK Department for International Development, and Wellcome Trust. PMID:23683639

Bile duct injury during cholecystectomy.

PubMed

Kapoor, V K

2015-08-01

Laparoscopic cholecystectomy (LC) is the treatment of choice for gallstones, but is associated with increased risk of bile duct injury (BDI bile duct injury). If the BDI is detected during LC can be addressed immediately, if available hepatobiliary surgeon, but the easiest and safest procedure for the general surgeon is placing drains into subhepatic region and the transfer of acute BDI to controlled external biliary fistula (external Biliary fistula EBF). Most BDI is diagnosed when the postoperative period, when there is biliary leak. Therapy is a percutaneous catheter drainage and endoscopic stenting in the bile duct; early repair is not recommended. Repair in the form hepatico-jejunostomy (HJ) should be performed hepatobiliary surgeon at intervals of 46 weeks after it closes EBF. BDI is a frequent cause medico-legal actions and a substantial burden on health care costs. Most BDI can be avoided by adherence to the principles of safe cholecystectomy.

Ethylene Promotes Cadmium-induced Root Growth Inhibition through EIN3 controlled XTH33 and LSU1 expression in Arabidopsis.

PubMed

Kong, Xiangpei; Li, Cuiling; Zhang, Feng; Yu, Qianqian; Gao, Shan; Zhang, Maolin; Tian, Huiyu; Zhang, Jian; Yuan, Xianzheng; Ding, Zhaojun

2018-06-05

Cadmium (Cd) stress is one of the most serious heavy metal stresses limiting plant growth and development. However, the molecular mechanisms underlying Cd-induced root growth inhibition remain unclear. Here, we found that ethylene signaling positively regulates Cd-induced root growth inhibition. Arabidopsis seedlings pretreated with the ethylene precursor 1-aminocyclopropane-1-carboxylic acid exhibited enhanced Cd-induced root growth inhibition; while the addition of the ethylene biosynthesis inhibitor aminoethoxyvinyl glycine decreased Cd-induced root growth inhibition. Consistently, ethylene-insensitive mutants such as ein4-1, ein3-1 eil1-1 double mutant, and EBF1ox, displayed an increased tolerance to Cd. Furthermore, we also observed that Cd inhibited EIN3 protein degradation, a process which was regulated by ethylene signaling. Genetic and biochemical analyses showed that EIN3 enhanced root growth inhibition under Cd stress through direct binding to the promoters and regulating the expression of XTH33 and LSU1, which encode key regulators of cell wall extension and S metabolic process, respectively. Collectively, our study demonstrates that ethylene plays a positive role in Cd-regulated root growth inhibition through EIN3-mediated transcriptional regulation of XTH33 and LSU1, and provides a molecular framework for the integration of environmental signals and intrinsic regulators in modulating plant root growth. This article is protected by copyright. All rights reserved.

A comparative modeling study on non-climatic and climatic risk assessment on Asian Tiger Mosquito (Aedes albopictus)

PubMed Central

Shafapour Tehrany, Mahyat; Solhjouy-fard, Samaneh; Kumar, Lalit

2018-01-01

Aedes albopictus, the Asian Tiger Mosquito, vector of Chikungunya, Dengue Fever and Zika viruses, has proven its hardy adaptability in expansion from its natural Asian, forest edge, tree hole habitat on the back of international trade transportation, re-establishing in temperate urban surrounds, in a range of water receptacles and semi-enclosures of organic matter. Conventional aerial spray mosquito vector controls focus on wetland and stagnant water expanses, proven to miss the protected hollows and crevices favoured by Ae. albopictus. New control or eradication strategies are thus essential, particular in light of potential expansions in the southeastern and eastern USA. Successful regional vector control strategies require risk level analysis. Should strategies prioritize regions with non-climatic or climatic suitability parameters for Ae. albopictus? Our study used current Ae. albopictus distribution data to develop two independent models: (i) regions with suitable non-climatic factors, and (ii) regions with suitable climate for Ae. albopictus in southeastern USA. Non-climatic model processing used Evidential Belief Function (EBF), together with six geographical conditioning factors (raster data layers), to establish the probability index. Validation of the analysis results was estimated with area under the curve (AUC) using Ae. albopictus presence data. Climatic modeling was based on two General Circulation Models (GCMs), Miroc3.2 and CSIRO-MK30 running the RCP 8.5 scenario in MaxEnt software. EBF non-climatic model results achieved a 0.70 prediction rate and 0.73 success rate, confirming suitability of the study site regions for Ae. albopictus establishment. The climatic model results showed the best-fit model comprised Coldest Quarter Mean Temp, Precipitation of Wettest Quarter and Driest Quarter Precipitation factors with mean AUC value of 0.86. Both GCMs showed that the whole study site is highly suitable and will remain suitable climatically, according to the prediction for 2055, for Ae. albopictus expansion. PMID:29576954

A comparative modeling study on non-climatic and climatic risk assessment on Asian Tiger Mosquito (Aedes albopictus).

PubMed

Shabani, Farzin; Shafapour Tehrany, Mahyat; Solhjouy-Fard, Samaneh; Kumar, Lalit

2018-01-01

Aedes albopictus , the Asian Tiger Mosquito, vector of Chikungunya, Dengue Fever and Zika viruses, has proven its hardy adaptability in expansion from its natural Asian, forest edge, tree hole habitat on the back of international trade transportation, re-establishing in temperate urban surrounds, in a range of water receptacles and semi-enclosures of organic matter. Conventional aerial spray mosquito vector controls focus on wetland and stagnant water expanses, proven to miss the protected hollows and crevices favoured by Ae. albopictus. New control or eradication strategies are thus essential, particular in light of potential expansions in the southeastern and eastern USA. Successful regional vector control strategies require risk level analysis. Should strategies prioritize regions with non-climatic or climatic suitability parameters for Ae. albopictus ? Our study used current Ae. albopictus distribution data to develop two independent models: (i) regions with suitable non-climatic factors, and (ii) regions with suitable climate for Ae. albopictus in southeastern USA. Non-climatic model processing used Evidential Belief Function (EBF), together with six geographical conditioning factors (raster data layers), to establish the probability index. Validation of the analysis results was estimated with area under the curve (AUC) using Ae. albopictus presence data. Climatic modeling was based on two General Circulation Models (GCMs), Miroc3.2 and CSIRO-MK30 running the RCP 8.5 scenario in MaxEnt software. EBF non-climatic model results achieved a 0.70 prediction rate and 0.73 success rate, confirming suitability of the study site regions for Ae. albopictus establishment. The climatic model results showed the best-fit model comprised Coldest Quarter Mean Temp, Precipitation of Wettest Quarter and Driest Quarter Precipitation factors with mean AUC value of 0.86. Both GCMs showed that the whole study site is highly suitable and will remain suitable climatically, according to the prediction for 2055, for Ae. albopictus expansion.

Distribution of putative xenogeneic silencers in prokaryote genomes.

PubMed

Perez-Rueda, Ernesto; Ibarra, J Antonio

2015-10-01

Gene silencing is an important function as it keeps newly acquired foreign DNA repressed, thereby avoiding possible deleterious effects in the host organism. Known transcriptional regulators associated with this process are called xenogeneic silencers (XS) and belong to either the H-NS, Lsr2, MvaT or Rok families. In the work described here we looked for XS-like regulators and their distribution in prokaryotic organisms was evaluated. Our analysis showed that putative XS regulators similar to H-NS, Lsr2, MvaT or Rok are present only in bacteria (31.7%). This does not exclude the existence of alternative XS in the rest of the organisms analyzed. Additionally, of the four XS groups evaluated in this work, those from the H-NS family have diversified more than the other groups. In order to compare the distribution of these putative XS regulators we also searched for other nucleoid-associated proteins (NAPs) not included in this group such as Fis, EbfC/YbaB, HU/IHF and Alba. Results showed that NAPs from the Fis, EbfC/YbaB, HU/IHF and Alba families are widely (94%) distributed among prokaryotes. These NAPs were found in multiple combinations with or without XS-like proteins. In regard with XS regulators, results showed that only XS proteins from one family were found in those organisms containing them. This suggests specificity for this type of regulators and their corresponding genomes. Copyright © 2015 Elsevier Ltd. All rights reserved.

3D printing in X-ray and Gamma-Ray Imaging: A novel method for fabricating high-density imaging apertures☆

PubMed Central

Miller, Brian W.; Moore, Jared W.; Barrett, Harrison H.; Fryé, Teresa; Adler, Steven; Sery, Joe; Furenlid, Lars R.

2011-01-01

Advances in 3D rapid-prototyping printers, 3D modeling software, and casting techniques allow for cost-effective fabrication of custom components in gamma-ray and X-ray imaging systems. Applications extend to new fabrication methods for custom collimators, pinholes, calibration and resolution phantoms, mounting and shielding components, and imaging apertures. Details of the fabrication process for these components, specifically the 3D printing process, cold casting with a tungsten epoxy, and lost-wax casting in platinum are presented. PMID:22199414

HIV status, breastfeeding modality at 5 months and postpartum maternal weight changes over 24 months in rural South Africa.

PubMed

Chetty, Terusha; Carter, Rosalind J; Bland, Ruth M; Newell, Marie-Louise

2014-07-01

To determine the effect of infant feeding practices on postpartum weight change among HIV-infected and -uninfected women in South Africa. In a non-randomised intervention cohort study of antiretroviral therapy-naïve women in South Africa, infants were classified as exclusive (EBF), mixed (MF) or non-breastfed (NBF) at each visit. We analysed infant feeding cumulatively from birth to 5 months using 24-hour feeding history (collected weekly for each of the preceding 7 days). Using generalised estimating equation mixed models, allowing for repeated measures, we compared postpartum weight change (kg) from the first maternal postpartum weight within the first 6 weeks (baseline weight) to each subsequent visit through 24 months among 2340 HIV-infected and -uninfected women with live births and at least two postpartum weight measurements. HIV-infected (-0.2 kg CI: -1.7 to 1.3 kg; P = 0.81) and -uninfected women (-0.5 kg; 95% CI: -2.1 to 1.2 kg; P = 0.58) had marginal non-significant weight loss from baseline to 24 months postpartum. Adjusting for HIV status, socio-demographic, pregnancy-related and infant factors, 5-month feeding modality was not significantly associated with postpartum weight change: weight change by 24 months postpartum, compared to the change in the reference EBF group, was 0.03 kg in NBF (95% CI: -2.5 to +2.5 kg; P = 0.90) and 0.1 kg in MF (95% CI: -3.0 to +3.2 kg; P = 0.78). HIV-infected and -uninfected women experienced similar weight loss over 24 months. Weight change postpartum was not associated with 5-month breastfeeding modality among HIV-infected and -uninfected women. © 2014 John Wiley & Sons Ltd.

Indirect three-dimensional printing of synthetic polymer scaffold based on thermal molding process.

PubMed

Park, Jeong Hun; Jung, Jin Woo; Kang, Hyun-Wook; Cho, Dong-Woo

2014-06-01

One of the major issues in tissue engineering has been the development of three-dimensional (3D) scaffolds, which serve as a structural template for cell growth and extracellular matrix formation. In scaffold-based tissue engineering, 3D printing (3DP) technology has been successfully applied for the fabrication of complex 3D scaffolds by using both direct and indirect techniques. In principle, direct 3DP techniques rely on the straightforward utilization of the final scaffold materials during the actual scaffold fabrication process. In contrast, indirect 3DP techniques use a negative mold based on a scaffold design, to which the desired biomaterial is cast and then sacrificed to obtain the final scaffold. Such indirect 3DP techniques generally impose a solvent-based process for scaffold fabrication, resulting in a considerable increase in the fabrication time and poor mechanical properties. In addition, the internal architecture of the resulting scaffold is affected by the properties of the biomaterial solution. In this study, we propose an advanced indirect 3DP technique using projection-based micro-stereolithography and an injection molding system (IMS) in order to address these challenges. The scaffold was fabricated by a thermal molding process using IMS to overcome the limitation of the solvent-based molding process in indirect 3DP techniques. The results indicate that the thermal molding process using an IMS has achieved a substantial reduction in scaffold fabrication time and has also provided the scaffold with higher mechanical modulus and strength. In addition, cell adhesion and proliferation studies have indicated no significant difference in cell activity between the scaffolds prepared by solvent-based and thermal molding processes.

Impact of process temperature on GaSb metal-oxide-semiconductor interface properties fabricated by ex-situ process

NASA Astrophysics Data System (ADS)

Yokoyama, Masafumi; Asakura, Yuji; Yokoyama, Haruki; Takenaka, Mitsuru; Takagi, Shinichi

2014-06-01

We have studied the impact of process temperature on interface properties of GaSb metal-oxide-semiconductor (MOS) structures fabricated by an ex-situ atomic-layer-deposition (ALD) process. We have found that the ALD temperature strongly affects the Al2O3/GaSb MOS interface properties. The Al2O3/GaSb MOS interfaces fabricated at the low ALD temperature of 150 °C have the minimum interface-trap density (Dit) of ˜4.5 × 1013 cm-2 eV-1. We have also found that the post-metalization annealing at temperature higher than 200 °C degrades the Al2O3/GaSb MOS interface properties. The low-temperature process is preferable in fabricating GaSb MOS interfaces in the ex-situ ALD process to avoid the high-temperature-induced degradations.

Heat treatment of expressed breast milk is a feasible option for feeding HIV-exposed, uninfected children after 6 months of age in rural Zimbabwe.

PubMed

Mbuya, Mduduzi N N; Humphrey, Jean H; Majo, Florence; Chasekwa, Bernard; Jenkins, Alison; Israel-Ballard, Kiersten; Muti, Monica; Paul, Keriann H; Madzima, Rufaro C; Moulton, Lawrence H; Stoltzfus, Rebecca J

2010-08-01

In the context of a prevention of mother to child transmission of HIV program promoting exclusive breast-feeding (EBF) to 6 mo and offering HIV-PCR testing at approximately 6 mo, we ascertained the feasibility of expressing and heat-treating (EHT) all breast milk fed to HIV-exposed, uninfected infants following 6 mo of EBF. Twenty mother-baby pairs were enrolled from a hospital in rural Zimbabwe. Research nurses provided lactation, EHT, and complementary feeding counseling through 21 home visits conducted over an 8-wk period and collected quantitative and qualitative data on the mothers' EHT experiences, children's diets, and anthropometric measurements. Mothers kept daily logs of EHT volumes and direct breast-feeding episodes. Mothers successfully initiated and sustained EHT for 4.5 mo (range, 1-11 mo), feeding 426 +/- 227 mL/d (mean +/- SD). By wk 2 of follow-up, children were receiving EHT and Nutributter-enriched complementary foods that satisfied 100% of their energy requirements. During the 8-wk follow-up period, no growth faltering was experienced [changes in weight-for-age, weight-for-length, and length-for-age Z scores = +0.03 +/- 0.50; +0.77 +/- 1.59; and +0.02 +/- 0.85 (mean +/- SD), respectively]. Stigma was not a major deterrent, likely due to a social marketing campaign for EBF that promoted EHT as a practice to sustain breast-feeding for all women. This study provides evidence that resource-poor rural women can initiate and sustain EHT given family and health systems support. EHT provides a strategy for improving the diets of HIV-exposed but uninfected children after direct breast-feeding has ceased.

Challenges faced by health-care providers offering infant-feeding counseling to HIV-positive women in sub-Saharan Africa: a review of current research.

PubMed

Tuthill, Emily L; Chan, Jessica; Butler, Lisa M

2015-01-01

Exclusive breastfeeding (EBF) has been identified as the optimal nutrition and critical behavior in attaining human immunodeficiency virus (HIV)-free infant survival in resource-limited settings. Health-care providers (HCPs) in clinic- and community-settings throughout sub-Saharan Africa (sSA) provide infant-feeding counseling. However, rates of EBF at 6 months of age are suboptimal. HCPs are uniquely positioned to educate HIV-positive mothers and provide support by addressing known barriers to EBF. However, limited evidence exists on the experiences faced by HCPs in providing counseling on infant feeding to HIV-positive women. Our objective is to describe experiences faced by HCPs when delivering infant-feeding counseling in the context of HIV in program settings in sSA. We searched a range of electronic databases, including PubMed, CINAHL, and PsycINFO from January 1990 to February 2013, in addition to hand-searching, cross-reference searching, and personal communications. The search was limited to publications in English. Empirical studies of HCP experiences providing infant-feeding counseling in the prevention of mother-to-child transmission (PMTCT) of HIV programs in sSA were selected. We identified 10 peer-reviewed articles reporting HCP challenges in infant-feeding counseling that met inclusion criteria. Articles included qualitative, cross-sectional and mixed-method studies, and cumulatively reported 31 challenges faced by HCPs. Among the challenges identified, the most commonly reported were personal beliefs held by the HCPs toward infant feeding in the context of HIV, contradictory messages, staff workload, directive counseling styles, and a lack of practical strategies to offer mothers, often leading to improvised counseling approaches. Counseling strategies need to be developed that are relevant, meaningful, and responsive to the needs of both HCPs and mothers.

The impact of sociodemographic and health-service factors on breast-feeding in sub-Saharan African countries with high diarrhoea mortality.

PubMed

Ogbo, Felix A; Eastwood, John; Page, Andrew; Efe-Aluta, Oniovo; Anago-Amanze, Chukwudi; Kadiri, Eshioramhe A; Ifegwu, Ifegwu K; Woolfenden, Sue; Agho, Kingsley E

2017-12-01

The current study aimed to examine the impact of sociodemographic and health-service factors on breast-feeding in sub-Saharan African (SSA) countries with high diarrhoea mortality. The study used the most recent and pooled Demographic and Health Survey data sets collected in nine SSA countries with high diarrhoea mortality. Multivariate logistic regression models that adjusted for cluster and sampling weights were used to investigate the association between sociodemographic and health-service factors and breast-feeding in SSA countries. Sub-Saharan Africa with high diarrhoea mortality. Children (n 50 975) under 24 months old (Burkina Faso (2010, N 5710); Demographic Republic of Congo (2013, N 6797); Ethiopia (2013, N 4193); Kenya (2014, N 7024); Mali (2013, N 3802); Niger (2013, N 4930); Nigeria (2013, N 11 712); Tanzania (2015, N 3894); and Uganda (2010, N 2913)). Overall prevalence of exclusive breast-feeding (EBF) and early initiation of breast-feeding (EIBF) was 35 and 44 %, respectively. Uganda, Ethiopia and Tanzania had higher EBF prevalence compared with Nigeria and Niger. Prevalence of EIBF was highest in Mali and lowest in Kenya. Higher educational attainment and frequent health-service visits of mothers (i.e. antenatal care, postnatal care and delivery at a health facility) were associated with EBF and EIBF. Breast-feeding practices in SSA countries with high diarrhoea mortality varied across geographical regions. To improve breast-feeding behaviours among mothers in SSA countries with high diarrhoea mortality, breast-feeding initiatives and policies should be context-specific, measurable and culturally appropriate, and should focus on all women, particularly mothers from low socio-economic groups with limited health-service access.

Development of wet process with substitution reaction for the mass production of Li 2TiO 3 pebbles

NASA Astrophysics Data System (ADS)

Tsuchiya, Kunihiko; Kawamura, Hiroshi

2000-12-01

Recently, lithium titanate (Li 2TiO 3) has attracted the attention of many researchers from the point of good tritium recovery at low temperature, chemical stability, etc. As the shape of Li 2TiO 3, a small pebble was selected as the Japanese design for a fusion reactor blanket. On the other hand, as the fabrication method of Li 2TiO 3 pebbles, the wet process is the most advantageous from the viewpoint of mass production, etc. In this study, fabrication of small Li 2TiO 3 pebbles less than ∅0.5 mm was performed by the wet process with substitution reaction, and the characteristics of Li 2TiO 3 pebbles fabricated by this process were evaluated. From the results of the fabrication tests, excellent prospects were obtained concerning mass production of Li 2TiO 3 pebbles with the target density (80-85% T.D.) and target diameter (less than ∅0.5 mm).

Piezoelectric Sol-Gel Composite Film Fabrication by Stencil Printing.

PubMed

Kaneko, Tsukasa; Iwata, Kazuki; Kobayashi, Makiko

2015-09-01

Piezoelectric films using sol-gel composites could be useful as ultrasonic transducers in various industrial fields. For sol-gel composite film fabrication, the spray coating technique has been used often because of its adaptability for various substrates. However, the spray technique requires multiple spray coating processes and heating processes and this is an issue of concern, especially for on-site fabrication in controlled areas. Stencil printing has been developed to solve this issue because this method can be used to fabricate thick sol-gel composite films with one coating process. In this study, PbTiO3 (PT)/Pb(Zr,Ti)O3 (PZT) films, PZT/PZT films, and Bi4Ti3O12 (BiT)/PZT films were fabricated by stencil printing, and PT/ PZT films were also fabricated using the spray technique. After fabrication, a thermal cycle test was performed for the samples to compare their ultrasonic performance. The sensitivity and signal-to-noise-ratio (SNR) of the ultrasonic response of PT/PZT fabricated by stencil printing were equivalent to those of PT/PZT fabricated by the spray technique, and better than those of other samples between room temperature and 300°C. Therefore, PT/PZT films fabricated by stencil printing could be a good candidate for nondestructive testing (NDT) ultrasonic transducers from room temperature to 300°C.

Acanthamoeba castellanii contains a ribosomal RNA enhancer binding protein which stimulates TIF-IB binding and transcription under stringent conditions.

PubMed

Yang, Q; Radebaugh, C A; Kubaska, W; Geiss, G K; Paule, M R

1995-11-11

The intergenic spacer (IGS) of Acanthamoeba castellanii rRNA genes contains repeated elements which are weak enhancers for transcription by RNA polymerase I. A protein, EBF, was identified and partially purified which binds to the enhancers and to several other sequences within the IGS, but not to other DNA fragments, including the rRNA core promoter. No consensus binding sequence could be discerned in these fragments and bound factor is in rapid equilibrium with unbound. EBF has functional characteristics similar to vertebrate upstream binding factors (UBF). Not only does it bind to the enhancer and other IGS elements, but it also stimulates binding of TIF-IB, the fundamental transcription initiation factor, to the core promoter and stimulates transcription from the promoter. Attempts to identify polypeptides with epitopes similar to rat or Xenopus laevis UBF suggest that structurally the protein from A.castellanii is not closely related to vertebrate UBF.

Acanthamoeba castellanii contains a ribosomal RNA enhancer binding protein which stimulates TIF-IB binding and transcription under stringent conditions.

PubMed Central

Yang, Q; Radebaugh, C A; Kubaska, W; Geiss, G K; Paule, M R

1995-01-01

The intergenic spacer (IGS) of Acanthamoeba castellanii rRNA genes contains repeated elements which are weak enhancers for transcription by RNA polymerase I. A protein, EBF, was identified and partially purified which binds to the enhancers and to several other sequences within the IGS, but not to other DNA fragments, including the rRNA core promoter. No consensus binding sequence could be discerned in these fragments and bound factor is in rapid equilibrium with unbound. EBF has functional characteristics similar to vertebrate upstream binding factors (UBF). Not only does it bind to the enhancer and other IGS elements, but it also stimulates binding of TIF-IB, the fundamental transcription initiation factor, to the core promoter and stimulates transcription from the promoter. Attempts to identify polypeptides with epitopes similar to rat or Xenopus laevis UBF suggest that structurally the protein from A.castellanii is not closely related to vertebrate UBF. Images PMID:7501455

Cooperative interactions enable singular olfactory receptor expression in mouse olfactory neurons

PubMed Central

Monahan, Kevin; Schieren, Ira; Cheung, Jonah; Mumbey-Wafula, Alice; Monuki, Edwin S

2017-01-01

The monogenic and monoallelic expression of only one out of >1000 mouse olfactory receptor (ORs) genes requires the formation of large heterochromatic chromatin domains that sequester the OR gene clusters. Within these domains, intergenic transcriptional enhancers evade heterochromatic silencing and converge into interchromosomal hubs that assemble over the transcriptionally active OR. The significance of this nuclear organization in OR choice remains elusive. Here, we show that transcription factors Lhx2 and Ebf specify OR enhancers by binding in a functionally cooperative fashion to stereotypically spaced motifs that defy heterochromatin. Specific displacement of Lhx2 and Ebf from OR enhancers resulted in pervasive, long-range, and trans downregulation of OR transcription, whereas pre-assembly of a multi-enhancer hub increased the frequency of OR choice in cis. Our data provide genetic support for the requirement and sufficiency of interchromosomal interactions in singular OR choice and generate general regulatory principles for stochastic, mutually exclusive gene expression programs. PMID:28933695

Study on γ-ray exposure buildup factors and fast neutron-shielding properties of some building materials

NASA Astrophysics Data System (ADS)

Singh, Vishwanath P.; Badiger, N. M.; El-Khayatt, A. M.

2014-06-01

We have computed γ-ray exposure buildup factors (EBF) of some building materials; glass, marble, flyash, cement, limestone, brick, plaster of paris (POP) and gypsum for energy 0.015-15 MeV up to 40 mfp (mfp, mean free path) penetration depth. Also, the macroscopic effective removal cross-sections (ΣR) for fast neutron were calculated. We discussed the dependency of EBF values on photon energy, penetration depth and chemical elements. The half-value layer and kinetic energy per unit mass relative to air of building materials were calculated for assessment of shielding effectiveness. Shielding thicknesses for glass, marble, flyash, cement, limestone and gypsum plaster (or Plaster of Paris, POP) were found comparable with ordinary concrete. Among the studied materials limestone and POP showed superior shielding properties for γ-ray and neutron, respectively. Radiation safety inside houses, schools and primary health centers for sheltering and annual dose can be assessed by the determination of shielding parameters of common building materials.

Acquisition of high metastatic capacity after in vitro fusion of a nonmetastatic tumor line with a bone marrow-derived macrophage

PubMed Central

1984-01-01

A low metastatic, thioguanine-resistant murine T lymphoma line (EbTGR) was hybridized in vitro, with the help of polyethylene glycol, with syngeneic bone marrow-derived macrophages. Two HAT-resistant hybrid lines (Eb-F1 and Eb-F2) were obtained from independent fusion cultures. A cytogenetic analysis revealed that most of the macrophage chromosomes except No. 12 had segregated or become rearranged 60 d after fusion, a time at which the cell lines had become stabilized in culture. Syngeneic mice inoculated subcutaneously with the tumor macrophage hybrid lines developed, very quickly, visceral metastases and died after less than 2 wk, while those inoculated with the parental line lived for greater than 6 wk and developed only localized, large primary tumors. The metastatic hybridomas expressed a similar tumor antigen as a spontaneous, in vivo derived, high metastatic variant (ESb) of the same tumor. This suggests that ESb cells might have arisen from a spontaneous fusion with a host macrophage. PMID:6491605

Gene Expression Profiling of Acute Lymphoblastic Leukemia in Children with Very Early Relapse.

PubMed

Núñez-Enríquez, Juan Carlos; Bárcenas-López, Diego Alberto; Hidalgo-Miranda, Alfredo; Jiménez-Hernández, Elva; Bekker-Méndez, Vilma Carolina; Flores-Lujano, Janet; Solis-Labastida, Karina Anastacia; Martínez-Morales, Gabriela Bibiana; Sánchez-Muñoz, Fausto; Espinoza-Hernández, Laura Eugenia; Velázquez-Aviña, Martha Margarita; Merino-Pasaye, Laura Elizabeth; García Velázquez, Alejandra Jimena; Pérez-Saldívar, María Luisa; Mojica-Espinoza, Raúl; Ramírez-Bello, Julián; Jiménez-Morales, Silvia; Mejía-Aranguré, Juan Manuel

2016-11-01

Acute lymphoblastic leukemia (ALL) is the most common childhood cancer worldwide. Mexican patients have high mortality rates, low frequency of good prognosis biomarkers (i.e., ETV6-RUNX1) and a high proportion is classified at the time of diagnosis with a high risk to relapse according to clinical features. In addition, very early relapses are more frequently observed than in other populations. The aim of the study was to identify new potential biomarkers associated with very early relapse in Mexican ALL children through transcriptome analysis. Microarray gene expression profiling on bone marrow samples of 54 pediatric ALL patients, collected at time of diagnosis and/or at relapse, was performed. Eleven patients presented relapse within the first 18 months after diagnosis. Affymetrix Human Transcriptome Array 2.0 (HTA 2.0) was used to perform gene expression analysis. Annotation and functional enrichment analyses were carried out using Gene Ontology, KEGG pathway analysis and Ingenuity Pathway Analysis tools. BLVRB, ZCCHC7, PAX5, EBF1, TMOD1 and BLNK were differentially expressed (fold-change >2.0 and p value <0.01) between relapsed and non-relapsed patients. Functional analysis of abnormally expressed genes revealed their important role in cellular processes related to the development of hematological diseases, cancer, cell death and survival and in cell-to-cell signaling interaction. Our data support previous findings showing the relevance of PAX5, EBF1 and ZCCHC7 as potential biomarkers to identify a subgroup of ALL children in high risk to relapse. Copyright © 2016 IMSS. Published by Elsevier Inc. All rights reserved.

Design fabrication and nondestructive testing of six experimental AGCarb/Intermold 3 cylinder assemblies

NASA Technical Reports Server (NTRS)

Thacher, E. F.

1972-01-01

Six subscale Intermold cylinder assemblies with a total of twelve different concepts for transition to AGCarb were fabricated. Three of the cylinder assemblies were made by helically winding the hoop fibers and three were of orthogonal configuration. The fabrication process is summarized and details of each manufacturing method are given. The objectives of the test program were to: (1) demonstrate the fabricability of the Intermold 3 subscale flanges, (2) produce an integral transition from Intermold 3 to AGCarb material, (3) define a workable manufacturing process, and (4) identify a best suited inspection method. The objectives were met and the results are described.

Genome-wide association study of offspring birth weight in 86 577 women identifies five novel loci and highlights maternal genetic effects that are independent of fetal genetics.

PubMed

Beaumont, Robin N; Warrington, Nicole M; Cavadino, Alana; Tyrrell, Jessica; Nodzenski, Michael; Horikoshi, Momoko; Geller, Frank; Myhre, Ronny; Richmond, Rebecca C; Paternoster, Lavinia; Bradfield, Jonathan P; Kreiner-Møller, Eskil; Huikari, Ville; Metrustry, Sarah; Lunetta, Kathryn L; Painter, Jodie N; Hottenga, Jouke-Jan; Allard, Catherine; Barton, Sheila J; Espinosa, Ana; Marsh, Julie A; Potter, Catherine; Zhang, Ge; Ang, Wei; Berry, Diane J; Bouchard, Luigi; Das, Shikta; Hakonarson, Hakon; Heikkinen, Jani; Helgeland, Øyvind; Hocher, Berthold; Hofman, Albert; Inskip, Hazel M; Jones, Samuel E; Kogevinas, Manolis; Lind, Penelope A; Marullo, Letizia; Medland, Sarah E; Murray, Anna; Murray, Jeffrey C; Njølstad, Pål R; Nohr, Ellen A; Reichetzeder, Christoph; Ring, Susan M; Ruth, Katherine S; Santa-Marina, Loreto; Scholtens, Denise M; Sebert, Sylvain; Sengpiel, Verena; Tuke, Marcus A; Vaudel, Marc; Weedon, Michael N; Willemsen, Gonneke; Wood, Andrew R; Yaghootkar, Hanieh; Muglia, Louis J; Bartels, Meike; Relton, Caroline L; Pennell, Craig E; Chatzi, Leda; Estivill, Xavier; Holloway, John W; Boomsma, Dorret I; Montgomery, Grant W; Murabito, Joanne M; Spector, Tim D; Power, Christine; Järvelin, Marjo-Ritta; Bisgaard, Hans; Grant, Struan F A; Sørensen, Thorkild I A; Jaddoe, Vincent W; Jacobsson, Bo; Melbye, Mads; McCarthy, Mark I; Hattersley, Andrew T; Hayes, M Geoffrey; Frayling, Timothy M; Hivert, Marie-France; Felix, Janine F; Hyppönen, Elina; Lowe, William L; Evans, David M; Lawlor, Debbie A; Feenstra, Bjarke; Freathy, Rachel M

2018-02-15

Genome-wide association studies of birth weight have focused on fetal genetics, whereas relatively little is known about the role of maternal genetic variation. We aimed to identify maternal genetic variants associated with birth weight that could highlight potentially relevant maternal determinants of fetal growth. We meta-analysed data on up to 8.7 million SNPs in up to 86 577 women of European descent from the Early Growth Genetics (EGG) Consortium and the UK Biobank. We used structural equation modelling (SEM) and analyses of mother-child pairs to quantify the separate maternal and fetal genetic effects. Maternal SNPs at 10 loci (MTNR1B, HMGA2, SH2B3, KCNAB1, L3MBTL3, GCK, EBF1, TCF7L2, ACTL9, CYP3A7) were associated with offspring birth weight at P < 5 × 10-8. In SEM analyses, at least 7 of the 10 associations were consistent with effects of the maternal genotype acting via the intrauterine environment, rather than via effects of shared alleles with the fetus. Variants, or correlated proxies, at many of the loci had been previously associated with adult traits, including fasting glucose (MTNR1B, GCK and TCF7L2) and sex hormone levels (CYP3A7), and one (EBF1) with gestational duration. The identified associations indicate that genetic effects on maternal glucose, cytochrome P450 activity and gestational duration, and potentially on maternal blood pressure and immune function, are relevant for fetal growth. Further characterization of these associations in mechanistic and causal analyses will enhance understanding of the potentially modifiable maternal determinants of fetal growth, with the goal of reducing the morbidity and mortality associated with low and high birth weights. © The Author(s) 2018. Published by Oxford University Press.

Genome-wide association study of offspring birth weight in 86 577 women identifies five novel loci and highlights maternal genetic effects that are independent of fetal genetics

PubMed Central

Beaumont, Robin N; Warrington, Nicole M; Cavadino, Alana; Tyrrell, Jessica; Nodzenski, Michael; Horikoshi, Momoko; Geller, Frank; Myhre, Ronny; Richmond, Rebecca C; Paternoster, Lavinia; Bradfield, Jonathan P; Kreiner-Møller, Eskil; Huikari, Ville; Metrustry, Sarah; Lunetta, Kathryn L; Painter, Jodie N; Hottenga, Jouke-Jan; Allard, Catherine; Barton, Sheila J; Espinosa, Ana; Marsh, Julie A; Potter, Catherine; Zhang, Ge; Ang, Wei; Berry, Diane J; Bouchard, Luigi; Das, Shikta; Hakonarson, Hakon; Heikkinen, Jani; Helgeland, Øyvind; Hocher, Berthold; Hofman, Albert; Inskip, Hazel M; Jones, Samuel E; Kogevinas, Manolis; Lind, Penelope A; Marullo, Letizia; Medland, Sarah E; Murray, Anna; Murray, Jeffrey C; Njølstad, Pål R; Nohr, Ellen A; Reichetzeder, Christoph; Ring, Susan M; Ruth, Katherine S; Santa-Marina, Loreto; Scholtens, Denise M; Sebert, Sylvain; Sengpiel, Verena; Tuke, Marcus A; Vaudel, Marc; Weedon, Michael N; Willemsen, Gonneke; Wood, Andrew R; Yaghootkar, Hanieh; Muglia, Louis J; Bartels, Meike; Relton, Caroline L; Pennell, Craig E; Chatzi, Leda; Estivill, Xavier; Holloway, John W; Boomsma, Dorret I; Montgomery, Grant W; Murabito, Joanne M; Spector, Tim D; Power, Christine; Järvelin, Marjo-Ritta; Bisgaard, Hans; Grant, Struan F A; Sørensen, Thorkild I A; Jaddoe, Vincent W; Jacobsson, Bo; Melbye, Mads; McCarthy, Mark I; Hattersley, Andrew T; Hayes, M Geoffrey; Frayling, Timothy M; Hivert, Marie-France; Felix, Janine F; Hyppönen, Elina; Lowe, William L; Evans, David M; Lawlor, Debbie A; Feenstra, Bjarke

2018-01-01

Abstract Genome-wide association studies of birth weight have focused on fetal genetics, whereas relatively little is known about the role of maternal genetic variation. We aimed to identify maternal genetic variants associated with birth weight that could highlight potentially relevant maternal determinants of fetal growth. We meta-analysed data on up to 8.7 million SNPs in up to 86 577 women of European descent from the Early Growth Genetics (EGG) Consortium and the UK Biobank. We used structural equation modelling (SEM) and analyses of mother–child pairs to quantify the separate maternal and fetal genetic effects. Maternal SNPs at 10 loci (MTNR1B, HMGA2, SH2B3, KCNAB1, L3MBTL3, GCK, EBF1, TCF7L2, ACTL9, CYP3A7) were associated with offspring birth weight at P < 5 × 10−8. In SEM analyses, at least 7 of the 10 associations were consistent with effects of the maternal genotype acting via the intrauterine environment, rather than via effects of shared alleles with the fetus. Variants, or correlated proxies, at many of the loci had been previously associated with adult traits, including fasting glucose (MTNR1B, GCK and TCF7L2) and sex hormone levels (CYP3A7), and one (EBF1) with gestational duration. The identified associations indicate that genetic effects on maternal glucose, cytochrome P450 activity and gestational duration, and potentially on maternal blood pressure and immune function, are relevant for fetal growth. Further characterization of these associations in mechanistic and causal analyses will enhance understanding of the potentially modifiable maternal determinants of fetal growth, with the goal of reducing the morbidity and mortality associated with low and high birth weights. PMID:29309628

Socio-economic resources, young child feeding practices, consumption of highly processed snacks and sugar-sweetened beverages: a population-based survey in rural northwestern Nicaragua.

PubMed

Contreras, Mariela; Blandón, Elmer Zelaya; Persson, Lars-Åke; Hjern, Anders; Ekström, Eva-Charlotte

2015-01-21

Socio-economic resources may be associated with infant feeding in complex patterns in societies undergoing a nutrition transition. This study evaluates associations of housing quality, food security and maternal education to the World Health Organization (WHO) feeding recommendations and to consumption of highly processed snacks (HP snacks) and sugar-sweetened beverages (SSBs) in rural Nicaragua. Data were collected from May to November 2009, with mothers of 0- to 35-month-olds being asked about young child feeding using a food frequency questionnaire. A validated questionnaire was used to assess household food insecurity and data were collected on maternal education and housing quality. Pearson's chi-squared test was used to compare proportions and determine associations between the resources and young child feeding. The three socio-economic resources and other confounders were introduced to multivariate logistic regression analyses to assess the independent contribution of the resources to the feeding practices and consumption of HP snacks and SSBs. Mothers with the lowest education level were more likely to be exclusively breastfeeding (EBF) their infants (OR not EBF: 0.19; 95% CI: 0.07, 0.51), whilst mothers of 6- to 35-month-olds in the lowest education category had more inadequate dietary diversity (DD) (OR for not meet DD: 2.04; 95% CI: 1.36, 3.08), were less likely to consume HP snacks (OR for HP snacks: 0.47; 95% CI: 0.32, 0.68) and SSBs (OR for SSBs: 0.68; 95% CI: 0.46, 0.98), compared to mothers with the highest level of education. Similarly, children residing in households with the highest food insecurity were also more prone to have inadequate dietary diversity (OR for not meet DD: 1.47; 95% CI: 1.05, 2.05). The odds for double burden of suboptimal feeding (concurrent inadequate diet and consumption of HP snacks/SSBs) were significantly lower in children of least educated mothers (OR: 0.64; 95% CI: 0.44, 0.92). Higher level of education was associated with both more and less adherence to the WHO recommended feeding practices as well as with more consumption of HP snacks and SSBs. Regardless of educational strata, the children in the community were exposed to suboptimal feeding practices conducive to both under- as well as overnutrition.

Integrated 3D printing and corona poling process of PVDF piezoelectric films for pressure sensor application

NASA Astrophysics Data System (ADS)

Kim, Hoejin; Torres, Fernando; Wu, Yanyu; Villagran, Dino; Lin, Yirong; Tseng, Tzu-Liang(Bill

2017-08-01

This paper presents a novel process to fabricate piezoelectric films from polyvinylidene fluoride (PVDF) polymer using integrated fused deposition modeling (FDM) 3D printing and corona poling technique. Corona poling is one of many effective poling processes that has received attention to activate PVDF as a piezoelectric responsive material. The corona poling process occurs when a PVDF polymer is exposed to a high electric field created and controlled through an electrically charged needle and a grid electrode under heating environment. FDM 3D printing has seen extensive progress in fabricating thermoplastic materials and structures, including PVDF. However, post processing techniques such as poling is needed to align the dipoles in order to gain piezoelectric properties. To further simplify the piezoelectric sensors and structures fabrication process, this paper proposes an integrated 3D printing process with corona poling to fabricate piezoelectric PVDF sensors without post poling process. This proposed process, named ‘Integrated 3D Printing and Corona poling process’ (IPC), uses the 3D printer’s nozzle and heating bed as anode and cathode, respectively, to create poling electric fields in a controlled heating environment. The nozzle travels along the programmed path with fixed distance between nozzle tip and sample’s top surface. Simultaneously, the electric field between the nozzle and bottom heating pad promotes the alignment of dipole moment of PVDF molecular chains. The crystalline phase transformation and output current generated by printed samples under different electric fields in this process were characterized by a Fourier transform infrared spectroscopy and through fatigue load frame. It is demonstrated that piezoelectric PVDF films with enhanced β-phase percentage can be fabricated using the IPC process. In addition, mechanical properties of printed PVDF was investigated by tensile testing. It is expected to expand the use of additive manufacturing to fabricate piezoelectric PVDF-based devices for applications such as sensing and energy harvesting.

Optical absorption and gamma-radiation-shielding parameter studies of Tm3+-doped multicomponent borosilicate glasses

NASA Astrophysics Data System (ADS)

Lakshminarayana, G.; Sayyed, M. I.; Baki, S. O.; Lira, A.; Dong, M. G.; Kaky, Kawa M.; Kityk, I. V.; Mahdi, M. A.

2018-05-01

Different concentrations (0.1‒2.0 mol%) of Tm3+-doped multicomponent borosilicate glasses with 10 mol% Li2O (alkali) or MgO (alkaline) have been synthesized and their optical absorption and radiation shielding features were studied. For both Li2O and MgO series 0.5 mol% Tm3+-doped glass samples, the evaluated Ωλ ( λ = 2, 4, and 6) Judd-Ofelt (JO) intensity parameters from experimental oscillator strengths were used in estimating the radiative transition probabilities ( A R), branching ratios ( β R), and radiative lifetimes ( τ R) for several emission transitions. Using the XCOM software, the mass attenuation coefficients ( µ/ ρ) for all the fabricated glasses were evaluated within the 0.015‒10 MeV energy range. Also, the ( µ/ ρ) values were calculated at 0.356, 0.662, 1.173, and 1.33 MeV photon energies by MCNP5 simulation code and the results were compared with those obtained by XCOM. The ( µ/ ρ) values for Li2O, as well as MgO series glasses, increase with the addition of Tm2O3 and these values for MgO series glasses are slightly higher with respect to Li2O series glasses. From the ( µ/ ρ) values, effective atomic number ( Z eff), half-value layer (HVL), and mean free path (MFP) were calculated and the HVL and MFP results revealed that high-energy photons have more penetration into a glass sample compared to low-energy photons. Further, geometric progression (GP) fitting method was utilized to calculate the exposure buildup factor (EBF) within the 0.015‒15 MeV energy range. The 2.0 mol% Tm2O3-doped glasses show a better ability to attenuate gamma-rays in comparison to other glass samples, so the addition of Tm2O3 content leads to improvement of the shielding efficiency of the prepared glasses.

Ensemble Bayesian forecasting system Part I: Theory and algorithms

NASA Astrophysics Data System (ADS)

Herr, Henry D.; Krzysztofowicz, Roman

2015-05-01

The ensemble Bayesian forecasting system (EBFS), whose theory was published in 2001, is developed for the purpose of quantifying the total uncertainty about a discrete-time, continuous-state, non-stationary stochastic process such as a time series of stages, discharges, or volumes at a river gauge. The EBFS is built of three components: an input ensemble forecaster (IEF), which simulates the uncertainty associated with random inputs; a deterministic hydrologic model (of any complexity), which simulates physical processes within a river basin; and a hydrologic uncertainty processor (HUP), which simulates the hydrologic uncertainty (an aggregate of all uncertainties except input). It works as a Monte Carlo simulator: an ensemble of time series of inputs (e.g., precipitation amounts) generated by the IEF is transformed deterministically through a hydrologic model into an ensemble of time series of outputs, which is next transformed stochastically by the HUP into an ensemble of time series of predictands (e.g., river stages). Previous research indicated that in order to attain an acceptable sampling error, the ensemble size must be on the order of hundreds (for probabilistic river stage forecasts and probabilistic flood forecasts) or even thousands (for probabilistic stage transition forecasts). The computing time needed to run the hydrologic model this many times renders the straightforward simulations operationally infeasible. This motivates the development of the ensemble Bayesian forecasting system with randomization (EBFSR), which takes full advantage of the analytic meta-Gaussian HUP and generates multiple ensemble members after each run of the hydrologic model; this auxiliary randomization reduces the required size of the meteorological input ensemble and makes it operationally feasible to generate a Bayesian ensemble forecast of large size. Such a forecast quantifies the total uncertainty, is well calibrated against the prior (climatic) distribution of predictand, possesses a Bayesian coherence property, constitutes a random sample of the predictand, and has an acceptable sampling error-which makes it suitable for rational decision making under uncertainty.

Impact of process temperature on GaSb metal-oxide-semiconductor interface properties fabricated by ex-situ process

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yokoyama, Masafumi, E-mail: yokoyama@mosfet.t.u-tokyo.ac.jp; Takenaka, Mitsuru; Takagi, Shinichi

We have studied the impact of process temperature on interface properties of GaSb metal-oxide-semiconductor (MOS) structures fabricated by an ex-situ atomic-layer-deposition (ALD) process. We have found that the ALD temperature strongly affects the Al{sub 2}O{sub 3}/GaSb MOS interface properties. The Al{sub 2}O{sub 3}/GaSb MOS interfaces fabricated at the low ALD temperature of 150 °C have the minimum interface-trap density (D{sub it}) of ∼4.5 × 10{sup 13 }cm{sup −2} eV{sup −1}. We have also found that the post-metalization annealing at temperature higher than 200 °C degrades the Al{sub 2}O{sub 3}/GaSb MOS interface properties. The low-temperature process is preferable in fabricating GaSb MOS interfaces in the ex-situmore » ALD process to avoid the high-temperature-induced degradations.« less

Optimizing The DSSC Fabrication Process Using Lean Six Sigma

NASA Astrophysics Data System (ADS)

Fauss, Brian

Alternative energy technologies must become more cost effective to achieve grid parity with fossil fuels. Dye sensitized solar cells (DSSCs) are an innovative third generation photovoltaic technology, which is demonstrating tremendous potential to become a revolutionary technology due to recent breakthroughs in cost of fabrication. The study here focused on quality improvement measures undertaken to improve fabrication of DSSCs and enhance process efficiency and effectiveness. Several quality improvement methods were implemented to optimize the seven step individual DSSC fabrication processes. Lean Manufacturing's 5S method successfully increased efficiency in all of the processes. Six Sigma's DMAIC methodology was used to identify and eliminate each of the root causes of defects in the critical titanium dioxide deposition process. These optimizations resulted with the following significant improvements in the production process: 1. fabrication time of the DSSCs was reduced by 54 %; 2. fabrication procedures were improved to the extent that all critical defects in the process were eliminated; 3. the quantity of functioning DSSCs fabricated was increased from 17 % to 90 %.

Breastfeeding indicators trends in Brazil for three decades

PubMed Central

Boccolini, Cristiano Siqueira; Boccolini, Patricia de Moraes Mello; Monteiro, Fernanda Ramos; Venâncio, Sonia Isoyama; Giugliani, Elsa Regina Justo

2017-01-01

ABSTRACT OBJECTIVE Update breastfeeding indicators trend in Brazil for the last three decades, incorporating more up-to-date information from the National Health Survey. METHODS We used secondary data from national surveys with information on breastfeeding (1986, 1996, 2006, and 2013) to construct the time series of prevalence for the following indicators: exclusive breastfeeding in children under six months of age (EBF6m), breastfeeding in toddlers under 2 years of age (BF), continued breastfeeding at one year of age (BF1year), and continued breastfeeding at two years of age (BF2years). RESULTS The prevalence of EBF6m, BF, and BF1year increased until 2006 (rising from 4.7%, 37.4%, and 25.5% in 1986 to 37.1%, 56.3%, and 47.2% in 2006, respectively). For these three indicators, there was relative stabilization between 2006 and 2013 (36.6%, 52.1%, and 45.4%, respectively). The BF2years indicator had a distinct behavior – relatively stable prevalence, around 25% between 1986 and 2006, and a subsequent increase, reaching 31.8% in 2013. CONCLUSIONS The time series of breastfeeding indicators in Brazil shows an upward trend until 2006, stabilizing from that date onwards on three of the four indicators evaluated. This result, which can be considered as a warning sign, requires evaluation and revision of policies and programs to promote, protect and support breastfeeding, strengthening existing ones and proposing new strategies so that the prevalence of breastfeeding indicators returns to an upwards trend. PMID:29166437

Novel Applications of Rapid Prototyping in Gamma-ray and X-ray Imaging

PubMed Central

Miller, Brian W.; Moore, Jared W.; Gehm, Michael E.; Furenlid, Lars R.; Barrett, Harrison H.

2010-01-01

Advances in 3D rapid-prototyping printers, 3D modeling software, and casting techniques allow for the fabrication of cost-effective, custom components in gamma-ray and x-ray imaging systems. Applications extend to new fabrication methods for custom collimators, pinholes, calibration and resolution phantoms, mounting and shielding components, and imaging apertures. Details of the fabrication process for these components are presented, specifically the 3D printing process, cold casting with a tungsten epoxy, and lost-wax casting in platinum. PMID:22984341

Infant feeding practices among HIV-positive women in Dar es Salaam, Tanzania, indicate a need for more intensive infant feeding counselling.

PubMed

Young, Sera L; Israel-Ballard, Kiersten A; Dantzer, Emily A; Ngonyani, Monica M; Nyambo, Margaret T; Ash, Deborah M; Chantry, Caroline J

2010-12-01

To assess feeding practices of infants born to HIV-positive women in Dar es Salaam, Tanzania. These data then served as a proxy to evaluate the adequacy of current infant feeding counselling. A cross-sectional survey of infant feeding behaviours. Four clinics in greater Dar es Salaam in early 2008. A total of 196 HIV-positive mothers of children aged 6-10 months recruited from HIV clinics. Initiation of breast-feeding was reported by 95·4 % of survey participants. In the entire sample, 80·1 %, 34·2 % and 13·3 % of women reported exclusive breast-feeding (EBF) up to 2, 4 and 6 months, respectively. Median duration of EBF among women who ever breast-fed was 3 (interquartile range (IQR): 2·1, 4·0) months. Most non-breast-milk foods fed to infants were low in nutrient density. Complete cessation of breast-feeding occurred within 14 d of the introduction of non-breast-milk foods among 138 of the 187 children (73·8 %) who had ever received any breast milk. Of the 187 infants in the study who ever received breast milk, 19·4 % received neither human milk nor any replacement milks for 1 week or more (median duration of no milk was 14 (IQR: 7, 152) d). Infant feeding practices among these HIV-positive mothers resulted in infants receiving far less breast milk and more mixed complementary feeds than recommended, thus placing them at greater risk of both malnutrition and HIV infection. An environment that better enables mothers to follow national guidelines is urgently needed. More intensive infant feeding counselling programmes would very likely increase rates of optimal infant feeding.

3D printed electromagnetic transmission and electronic structures fabricated on a single platform using advanced process integration techniques

NASA Astrophysics Data System (ADS)

Deffenbaugh, Paul Issac

3D printing has garnered immense attention from many fields including in-office rapid prototyping of mechanical parts, outer-space satellite replication, garage functional firearm manufacture, and NASA rocket engine component fabrication. 3D printing allows increased design flexibility in the fabrication of electronics, microwave circuits and wireless antennas and has reached a level of maturity which allows functional parts to be printed. Much more work is necessary in order to perfect the processes of 3D printed electronics especially in the area of automation. Chapter 1 shows several finished prototypes of 3D printed electronics as well as newly developed techniques in fabrication. Little is known about the RF and microwave properties and applications of the standard materials which have been developed for 3D printing. Measurement of a wide variety of materials over a broad spectrum of frequencies up to 10 GHz using a variety of well-established measurement methods is performed throughout chapter 2. Several types of high frequency RF transmission lines are fabricated and valuable model-matched data is gathered and provided in chapter 3 for future designers' use. Of particular note is a fully 3D printed stripline which was automatically fabricated in one process on one machine. Some core advantages of 3D printing RF/microwave components include rapid manufacturing of complex, dimensionally sensitive circuits (such as antennas and filters which are often iteratively tuned) and the ability to create new devices that cannot be made using standard fabrication techniques. Chapter 4 describes an exemplary fully 3D printed curved inverted-F antenna.

A novel fabrication method for suspended high-aspect-ratio microstructures

NASA Astrophysics Data System (ADS)

Yang, Yao-Joe; Kuo, Wen-Cheng

2005-11-01

Suspended high-aspect-ratio structures (suspended HARS) are widely used for MEMS devices such as micro-gyroscopes, micro-accelerometers, optical switches and so on. Various fabrication methods, such as SOI, SCREAM, AIM, SBM and BELST processes, were proposed to fabricate HARS. However, these methods focus on the fabrication of suspended microstructures with relatively small widths of trench opening (e.g. less than 10 µm). In this paper, we propose a novel process for fabricating very high-aspect-ratio suspended structures with large widths of trench opening using photoresist as an etching mask. By enhancing the microtrenching effect, we can easily release the suspended structure without thoroughly removing the floor polymer inside the trenches for the cases with a relatively small trench aspect ratio. All the process steps can be integrated into a single-run single-mask ICP-RIE process, which effectively reduces the process complexity and fabrication cost. We also discuss the phenomenon of corner erosion, which results in the undesired etching of silicon structures during the structure-releasing step. By using the proposed process, 100 µm thick suspended structures with the trench aspect ratio of about 20 are demonstrated. Also, the proposed process can be used to fabricate devices for applications which require large in-plane displacement. This paper was orally presented in the Transducers'05, Seoul, Korea (paper ID: 3B1.3).

Processing Science of Epoxy Resin Composites

DTIC Science & Technology

1984-01-15

3 2.2 LAMINATE FABRICATION 30 2.2.1 Baseline Laminate Fabrication 30 2.2.2 Large Laminate Fabrication 36 2.3 DIFFUSIVITY AND SOLUBILITY...Thick Laminate 42 28 Baseline Cure Cycle With Specimen Advancement Levels 45 29 Composite Panel Fabrication 47 30 Composite Panel Fabrication 48 31...first change was the elimination of the different 1 resin formulations and concentration on the normal or baseline 5208/T300 prepreg as produced by

Fabrication of three-dimensional hybrid nanostructure-embedded ITO and its application as a transparent electrode for high-efficiency solution processable organic photovoltaic devices.

PubMed

Kim, Jeong Won; Jeon, Hwan-Jin; Lee, Chang-Lyoul; Ahn, Chi Won

2017-03-02

Well-aligned, high-resolution (10 nm), three-dimensional (3D) hybrid nanostructures consisting of patterned cylinders and Au islands were fabricated on ITO substrates using an ion bombardment process and a tilted deposition process. The fabricated 3D hybrid nanostructure-embedded ITO maintained its excellent electrical and optical properties after applying a surface-structuring process. The solution processable organic photovoltaic device (SP-OPV) employing a 3D hybrid nanostructure-embedded ITO as the anode displayed a 10% enhancement in the photovoltaic performance compared to the photovoltaic device prepared using a flat ITO electrode, due to the improved charge collection (extraction and transport) efficiency as well as light absorbance by the photo-active layer.

A Self-Aligned a-IGZO Thin-Film Transistor Using a New Two-Photo-Mask Process with a Continuous Etching Scheme.

PubMed

Fan, Ching-Lin; Shang, Ming-Chi; Li, Bo-Jyun; Lin, Yu-Zuo; Wang, Shea-Jue; Lee, Win-Der

2014-08-11

Minimizing the parasitic capacitance and the number of photo-masks can improve operational speed and reduce fabrication costs. Therefore, in this study, a new two-photo-mask process is proposed that exhibits a self-aligned structure without an etching-stop layer. Combining the backside-ultraviolet (BUV) exposure and backside-lift-off (BLO) schemes can not only prevent the damage when etching the source/drain (S/D) electrodes but also reduce the number of photo-masks required during fabrication and minimize the parasitic capacitance with the decreasing of gate overlap length at same time. Compared with traditional fabrication processes, the proposed process yields that thin-film transistors (TFTs) exhibit comparable field-effect mobility (9.5 cm²/V·s), threshold voltage (3.39 V), and subthreshold swing (0.3 V/decade). The delay time of an inverter fabricated using the proposed process was considerably decreased.

A Self-Aligned a-IGZO Thin-Film Transistor Using a New Two-Photo-Mask Process with a Continuous Etching Scheme

PubMed Central

Fan, Ching-Lin; Shang, Ming-Chi; Li, Bo-Jyun; Lin, Yu-Zuo; Wang, Shea-Jue; Lee, Win-Der

2014-01-01

Minimizing the parasitic capacitance and the number of photo-masks can improve operational speed and reduce fabrication costs. Therefore, in this study, a new two-photo-mask process is proposed that exhibits a self-aligned structure without an etching-stop layer. Combining the backside-ultraviolet (BUV) exposure and backside-lift-off (BLO) schemes can not only prevent the damage when etching the source/drain (S/D) electrodes but also reduce the number of photo-masks required during fabrication and minimize the parasitic capacitance with the decreasing of gate overlap length at same time. Compared with traditional fabrication processes, the proposed process yields that thin-film transistors (TFTs) exhibit comparable field-effect mobility (9.5 cm2/V·s), threshold voltage (3.39 V), and subthreshold swing (0.3 V/decade). The delay time of an inverter fabricated using the proposed process was considerably decreased. PMID:28788159

3D Nanofabrication Using AFM-Based Ultrasonic Vibration Assisted Nanomachining

NASA Astrophysics Data System (ADS)

Deng, Jia

Nanolithography and nanofabrication processes have significant impact on the recent development of fundamental research areas such as physics, chemistry and biology, as well as the modern electronic devices that have reached nanoscale domain such as optoelectronic devices. Many advanced nanofabrication techniques have been developed and reported to satisfy different requirements in both research areas and applications such as electron-beam lithography. However, it is expensive to use and maintain the equipment. Atomic Force Microscope (AFM) based nanolithography processes provide an alternative approach to nanopatterning with significantly lower cost. Recently, three dimensional nanostructures have attracted a lot of attention, motivated by many applications in various fields including optics, plasmonics and nanoelectromechanical systems. AFM nanolithography processes are able to create not only two dimensional nanopatterns but also have the great potential to fabricate three dimensional nanostructures. The objectives of this research proposal are to investigate the capability of AFM-based three dimensional nanofabrication processes, to transfer the three dimensional nanostructures from resists to silicon surfaces and to use the three dimensional nanostructures on silicon in applications. Based on the understanding of literature, a novel AFM-based ultrasonic vibration assisted nanomachining system is utilized to develop three dimensional nanofabrication processes. In the system, high-frequency in plane circular xy-vibration was introduced to create a virtual tool, whose diameter is controlled by the amplitude of xy-vibration and is larger than that of a regular AFM tip. Therefore, the feature width of a single trench is tunable. Ultrasonic vibration of sample in z-direction was introduced to control the depth of single trenches, creating a high-rate 3D nanomachining process. Complicated 3D nanostructures on PMMA are fabricated under both the setpoint force and z-height control modes. Complex contours and both discrete and continuous height changes are able to be fabricated by the novel 3D nanofabrication processes. Results are imaged clearly after cleaning the debris covering on the 3D nanostructures after nanomachining process. The process is validated by fabricating various 3D nanostructures. The advantages and disadvantages are compared between these two control modes. Furthermore, the 3D nanostructures were further transferred from PMMA surfaces onto silicon surfaces using reactive ion etching (RIE) process. Recipes are developed based on the functionality of the etching gas in the transfer process. Tunable selectivity and controllable surface finishes are achieved by varying the flow rate of oxygen. The developed 3D nanofabrication process is used as a novel technique in two applications, master fabrication for soft lithography and SERS substrates fabrication. 3D nanostructures were reversely molded on PDMS and then duplicated on new PMMA substrates. 3D nanostructures are fabricated, which can be either directly used or transferred on silicon as SERS substrates after coating 80 nm gold layers. They greatly enhanced the intensity of Raman scattering with the enhancement factor of 3.11x103. These applications demonstrate the capability of the novel process of AFM-based 3D nanomachining.

The research on surface characteristics of optical lens by 3D printing technique and precise diamond turning technique

NASA Astrophysics Data System (ADS)

Huang, Chien-Yao; Chang, Chun-Ming; Ho, Cheng-Fong; Lee, Tai-Wen; Lin, Ping-Hung; Hsu, Wei-Yao

2017-06-01

The advantage of 3D printing technique is flexible in design and fabrication. Using 3D printing technique, the traditional manufacturing limitations are not considered. The optical lens is the key component in an optical system. The traditional process to manufacture optical plastic lens is injection molding. However injection molding is only suitable for plastics lens, it cannot fabricate optical and mechanical components at same time. The assembly error of optical system can be reduced effectively with fabricating optical and mechanical components at same time. The process of printing optical and mechanical components simultaneously is proposed in previous papers, but the optical surface of printing components is not transparent. If we increase the transmittance of the optical surface, the printing components which fabricated by 3D printing process could be high transmission. Therefore, precise diamond turning technique has been used to turning the surface of 3D printing optical lens in this paper. The precise diamond turning techniques could process surfaces of components to meet the requirements of optical system. A 3D printing machine, Stratasys Connex 500, and a precise diamond turning machine, Precitech Freeform705XG, have been used in this paper, respectively. The dimension, roughness, transmission and printing types of 3D printing components have been discussed in this paper. After turning and polishing process, the roughness of 3D printing component is below 0.05 μm and the transmittance increase above 80 %. This optical module can be used in hand-held telescope and other system which need lens and special mechanical structure fabricated simultaneously.

Fabrication and Characterization of High Strength Al-Cu Alloys Processed Using Laser Beam Melting in Metal Powder Bed

NASA Astrophysics Data System (ADS)

Ahuja, Bhrigu; Karg, Michael; Nagulin, Konstantin Yu.; Schmidt, Michael

The proposed paper illustrates fabrication and characterization of high strength Aluminium Copper alloys processed using Laser Beam Melting process. Al-Cu alloys EN AW-2219 and EN AW-2618 are classified as wrought alloys and 2618 is typically considered difficult to weld. Laser Beam Melting (LBM) process from the family of Additive Manufacturing processes, has the unique ability to form fully dense complex 3D geometries using micro sized metallic powder in a layer by layer fabrication methodology. LBM process can most closely be associated to the conventional laser welding process, but has significant differences in terms of the typical laser intensities and scan speeds used. Due to the use of high intensities and fast scan speeds, the process induces extremely high heating and cooling rates. This property gives it a unique physical attribute and therefore its ability to process high strength Al-Cu alloys needs to be investigated. Experiments conducted during the investigations associate the induced energy density controlled by varying process parameters to the achieved relative densities of the fabricated 3D structures.

Fabrication of nano-scale Cu bond pads with seal design in 3D integration applications.

PubMed

Chen, K N; Tsang, C K; Wu, W W; Lee, S H; Lu, J Q

2011-04-01

A method to fabricate nano-scale Cu bond pads for improving bonding quality in 3D integration applications is reported. The effect of Cu bonding quality on inter-level via structural reliability for 3D integration applications is investigated. We developed a Cu nano-scale-height bond pad structure and fabrication process for improved bonding quality by recessing oxides using a combination of SiO2 CMP process and dilute HF wet etching. In addition, in order to achieve improved wafer-level bonding, we introduced a seal design concept that prevents corrosion and provides extra mechanical support. Demonstrations of these concepts and processes provide the feasibility of reliable nano-scale 3D integration applications.

Fabrication of Large YBCO Superconducting Disks

NASA Technical Reports Server (NTRS)

Koczor, Ronald J.; Noever, David A.; Robertson, Glen A.

1999-01-01

We have undertaken fabrication of large bulk items to develop a repeatable process and to provide test articles in laboratory experiments investigating reported coupling of electromagnetic fields with the local gravity field in the presence of rotating superconducting disks. A successful process was developed which resulted in fabrication of 30 cm diameter annular disks. The disks were fabricated of the superconductor YBa2Cu3O(7-x). Various material parameters of the disks were measured.

Application of Dempster-Shafer theory of evidence model to geoelectric and hydraulic parameters for groundwater potential zonation

NASA Astrophysics Data System (ADS)

Mogaji, Kehinde Anthony; Lim, Hwee San

2018-06-01

The application of a GIS - based Dempster - Shafer data driven model named as evidential belief function EBF- methodology to groundwater potential conditioning factors (GPCFs) derived from geophysical and hydrogeological data sets for assessing groundwater potentiality was presented in this study. The proposed method's efficacy in managing degree of uncertainty in spatial predictive models motivated this research. The method procedural approaches entail firstly, the database containing groundwater data records (bore wells location inventory, hydrogeological data record, etc.) and geophysical measurement data construction. From the database, different influencing groundwater occurrence factors, namely aquifer layer thickness, aquifer layer resistivity, overburden material resistivity, overburden material thickness, aquifer hydraulic conductivity and aquifer transmissivity were extracted and prepared. Further, the bore well location inventories were partitioned randomly into a ratio of 70% (19 wells) for model training and 30% (9 wells) for model testing. The synthesized of the GPCFs via applying the DS - EBF model algorithms produced the groundwater productivity potential index (GPPI) map which demarcated the area into low - medium, medium, medium - high and high potential zones. The analyzed percentage degree of uncertainty for the predicted lows potential zones classes and mediums/highs potential zones classes are >10% and <10%, respectively. The DS theory model-based GPPI map's validation through ROC approach established prediction rate accuracy of 88.8%. Successively, the determined transverse resistance (TR) values in the range of 1280 and 30,000 Ω my for the area geoelectrically delineated aquifer units of the predicted potential zones through Dar - Zarrouk Parameter analysis quantitatively confirm the DS theory modeling prediction results. This research results have expand the capability of DS - EBF model in predictive modeling by effective uncertainty management. Thus, the produced map could form part of decision support system reliable to be used by local authorities for groundwater exploitation and management in the area.

Sandia MEMS Visualization Tools v. 3.0

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yarberry, Victor; Jorgensen, Craig R.; Young, Andrew I.

This is a revision to the Sandia MEMS Visualization Tools. It replaces all previous versions. New features in this version: Support for AutoCAD 2014 and 2015 . This CD contains an integrated set of electronic files that: a) Provides a 2D Process Visualizer that generates cross-section images of devices constructed using the SUMMiT V fabrication process. b) Provides a 3D Visualizer that generates 3D images of devices constructed using the SUMMiT V fabrication process. c) Provides a MEMS 3D Model generator that creates 3D solid models of devices constructed using the SUMMiT V fabrication process. While there exists some filesmore » on the CD that are used in conjunction with software package AutoCAD , these files are not intended for use independent of the CD. Note that the customer must purchase his/her own copy of AutoCAD to use with these files.« less

Development of lightweight graphite/polyimide sandwich panels, phases 3, 4 and 5

NASA Technical Reports Server (NTRS)

Merlette, J. B.

1972-01-01

Work performed in the last three phases of the program included: (1) face sheet processing; (2) honeycomb core manufacture; (3) face sheet-to-core bonding development; and (4) sandwich panel fabrication and testing. Resin cure studies were a major portion of this effort since processing problems traced to the polyimide matrix resin had to be resolved before quality core and face sheets could be fabricated. Honeycomb core fabrication and testing were conducted by Hexcel Corporation. A total of four graphite/polyimide resin composite cores were fabricated, tested, and reported. Two sandwich panels weighing .48 and .58 lb/sq ft, respectively were designed and fabricated which meet the support structure loads for the shuttle orbiter thermal protection system.

HIV status, breastfeeding modality at 5 months and postpartum maternal weight changes over 24 months in rural South Africa

PubMed Central

Chetty, Terusha; Carter, Rosalind J; Bland, Ruth M; Newell, Marie-Louise

2014-01-01

Objective To determine the effect of infant feeding practices on postpartum weight change among HIV-infected and -uninfected women in South Africa. Methods In a non-randomised intervention cohort study of antiretroviral therapy-naïve women in South Africa, infants were classified as exclusive (EBF), mixed (MF) or non-breastfed (NBF) at each visit. We analysed infant feeding cumulatively from birth to 5 months using 24-hour feeding history (collected weekly for each of the preceding 7 days). Using generalised estimating equation mixed models, allowing for repeated measures, we compared postpartum weight change (kg) from the first maternal postpartum weight within the first 6 weeks (baseline weight) to each subsequent visit through 24 months among 2340 HIV-infected and -uninfected women with live births and at least two postpartum weight measurements. Results HIV-infected (−0.2 kg CI: −1.7 to 1.3 kg; P = 0.81) and -uninfected women (−0.5 kg; 95% CI: −2.1 to 1.2 kg; P = 0.58) had marginal non-significant weight loss from baseline to 24 months postpartum. Adjusting for HIV status, socio-demographic, pregnancy-related and infant factors, 5-month feeding modality was not significantly associated with postpartum weight change: weight change by 24 months postpartum, compared to the change in the reference EBF group, was 0.03 kg in NBF (95% CI: −2.5 to +2.5 kg; P = 0.90) and 0.1 kg in MF (95% CI: −3.0 to +3.2 kg; P = 0.78). Conclusion HIV-infected and -uninfected women experienced similar weight loss over 24 months. Weight change postpartum was not associated with 5-month breastfeeding modality among HIV-infected and -uninfected women. PMID:24720779

Preform Characterization in VARTM Process Model Development

NASA Technical Reports Server (NTRS)

Grimsley, Brian W.; Cano, Roberto J.; Hubert, Pascal; Loos, Alfred C.; Kellen, Charles B.; Jensen, Brian J.

2004-01-01

Vacuum-Assisted Resin Transfer Molding (VARTM) is a Liquid Composite Molding (LCM) process where both resin injection and fiber compaction are achieved under pressures of 101.3 kPa or less. Originally developed over a decade ago for marine composite fabrication, VARTM is now considered a viable process for the fabrication of aerospace composites (1,2). In order to optimize and further improve the process, a finite element analysis (FEA) process model is being developed to include the coupled phenomenon of resin flow, preform compaction and resin cure. The model input parameters are obtained from resin and fiber-preform characterization tests. In this study, the compaction behavior and the Darcy permeability of a commercially available carbon fabric are characterized. The resulting empirical model equations are input to the 3- Dimensional Infiltration, version 5 (3DINFILv.5) process model to simulate infiltration of a composite panel.

ALLERGIC PROCTOCOLITIS IN INFANTS: analysis of the evolution of the nutritional status.

PubMed

Camargo, Ludmilla S; Silveira, Jonas Ac; Taddei, José Aac; Fagundes, Ulysses

2016-01-01

Allergic proctocolitis is a disease that affects infants in the first months. The change in feed is the primary factor for clinical improvement and maintenance of the nutritional status of the infant. Study the anthropometric evolution of infants with allergic proctocolitis at diagnosis and 1 to 6 months after nutritional intervention. A retrospective cohort of infants with allergic proctocolitis diagnosis followed at the Pediatric Gastroenterology Institute of São Paulo (IGASTROPED), Brazil. The database with clinical, therapeutic and anthropometric data was obtained from medical records of outpatient infants. The therapeutic intervention was characterized by 1) exclusive breastfeeding with maternal exclusion diet of the six allergens (EBF-MED) or 2) no breastfeeding and use of hypoallergenic formulas. Of the 44 infants diagnosed with allergic proctocolitis, 23 were female. The median age of the infants was 3.5 months at the time of admission and 6 months after the intervention. The main clinical complaint was hematochezia with or without other symptoms of allergic proctocolitis. No difference was shown in the infants anthropometric evaluation between the two diets. The duration of the allergic proctocolitis did not induce worsening of the infants nutritional status. Importantly, both nutritional interventions were able to keep the infants within the growth channel and resulted in the total clinical symptoms remission. Considering the fundamental mother-child link promoted by breastfeeding, the present data highlights the beneficial role of EBF-MED on the nutritional status of infants diagnosed with allergic proctocolitis in addition to the lower cost that breastfeeding brings compared the use of hypoallergenic formulas.

Recommendations for Infant Feeding Policy and Programs in Dzimauli Region, South Africa: Results From the MAL-ED Birth Cohort.

PubMed

Mushaphi, Lindelani Fhumudzani; Mahopo, Tjale Cloupas; Nesamvuni, Cebisa Noxolo; Baloyi, Brenda; Mashau, Ellen; Richardson, Jeniata; Dillingham, Rebecca; Guerrant, Richard; Ambikapathi, Ramya; Bessong, Pascal

2017-09-01

There is strong evidence that exclusive breastfeeding (EBF) in the first 6 months of life reduces the risk of diseases in infancy and in later life. To understand the maternal reasoning that influences optimum infant feeding practices of caregivers in semirural communities of Limpopo province. Nested qualitative study among mothers in an ongoing birth cohort study was conducted; structured and semi-structured interviews were used to collect data. Data from 234 infants after 6 months of follow-up was included for quantitative analysis. Four focus discussion groups comprising 7 to 10 caregivers were used to obtain perception of mothers on breastfeeding. A semi-structured interview guide was used to stimulate discussions. Thematic content analyses were conducted to identify the main themes that influence breastfeeding practices of caregivers. Over 90% of the caregivers initiated breastfeeding after delivery. However, less than 1% of mothers practiced EBF by 3 months, and none of the children were exclusively breastfed for up to 6 months. All caregivers introduced non-breast milk liquids and solids by the second month of child's life. Common reasons for introducing non-breast milk foods included insufficiency of breast milk production, going back to work or school, and influence by elderly women (mothers/mothers-in-law) and church members. Exclusive breastfeeding was not practiced in this community due to cultural and religious beliefs and misinformation. The involvement of elderly women and church members in infant feeding education and promotion programs and the dissemination of breastfeeding information through mobile phones to younger mothers are recommended.

Design Application Translates 2-D Graphics to 3-D Surfaces

NASA Technical Reports Server (NTRS)

2007-01-01

Fabric Images Inc., specializing in the printing and manufacturing of fabric tension architecture for the retail, museum, and exhibit/tradeshow communities, designed software to translate 2-D graphics for 3-D surfaces prior to print production. Fabric Images' fabric-flattening design process models a 3-D surface based on computer-aided design (CAD) specifications. The surface geometry of the model is used to form a 2-D template, similar to a flattening process developed by NASA's Glenn Research Center. This template or pattern is then applied in the development of a 2-D graphic layout. Benefits of this process include 11.5 percent time savings per project, less material wasted, and the ability to improve upon graphic techniques and offer new design services. Partners include Exhibitgroup/Giltspur (end-user client: TAC Air, a division of Truman Arnold Companies Inc.), Jack Morton Worldwide (end-user client: Nickelodeon), as well as 3D Exhibits Inc., and MG Design Associates Corp.

Fabrication of 3D solenoid microcoils in silica glass by femtosecond laser wet etch and microsolidics

NASA Astrophysics Data System (ADS)

Meng, Xiangwei; Yang, Qing; Chen, Feng; Shan, Chao; Liu, Keyin; Li, Yanyang; Bian, Hao; Du, Guangqing; Hou, Xun

2015-02-01

This paper reports a flexible fabrication method for 3D solenoid microcoils in silica glass. The method consists of femtosecond laser wet etching (FLWE) and microsolidics process. The 3D microchannel with high aspect ratio is fabricated by an improved FLWE method. In the microsolidics process, an alloy was chosen as the conductive metal. The microwires are achieved by injecting liquid alloy into the microchannel, and allowing the alloy to cool and solidify. The alloy microwires with high melting point can overcome the limitation of working temperature and improve the electrical property. The geometry, the height and diameter of microcoils were flexibly fabricated by the pre-designed laser writing path, the laser power and etching time. The 3D microcoils can provide uniform magnetic field and be widely integrated in many magnetic microsystems.

Method for double-sided processing of thin film transistors

DOEpatents

Yuan, Hao-Chih; Wang, Guogong; Eriksson, Mark A.; Evans, Paul G.; Lagally, Max G.; Ma, Zhenqiang

2008-04-08

This invention provides methods for fabricating thin film electronic devices with both front- and backside processing capabilities. Using these methods, high temperature processing steps may be carried out during both frontside and backside processing. The methods are well-suited for fabricating back-gate and double-gate field effect transistors, double-sided bipolar transistors and 3D integrated circuits.

Front and backside processed thin film electronic devices

DOEpatents

Yuan, Hao-Chih; Wang, Guogong; Eriksson, Mark A.; Evans, Paul G.; Lagally, Max G.; Ma, Zhenqiang

2010-10-12

This invention provides methods for fabricating thin film electronic devices with both front- and backside processing capabilities. Using these methods, high temperature processing steps may be carried out during both frontside and backside processing. The methods are well-suited for fabricating back-gate and double-gate field effect transistors, double-sided bipolar transistors and 3D integrated circuits.

3D MEMS in Standard Processes: Fabrication, Quality Assurance, and Novel Measurement Microstructures

NASA Technical Reports Server (NTRS)

Lin, Gisela; Lawton, Russell A.

2000-01-01

Three-dimensional MEMS microsystems that are commercially fabricated require minimal post-processing and are easily integrated with CMOS signal processing electronics. Measurements to evaluate the fabrication process (such as cross-sectional imaging and device performance characterization) provide much needed feedback in terms of reliability and quality assurance. MEMS technology is bringing a new class of microscale measurements to fruition. The relatively small size of MEMS microsystems offers the potential for higher fidelity recordings compared to macrosize counterparts, as illustrated in the measurement of muscle cell forces.

Flow-through polymerase chain reaction inside a seamless 3D helical microreactor fabricated utilizing a silicone tube and a paraffin mold.

PubMed

Wu, Wenming; Trinh, Kieu The Loan; Lee, Nae Yoon

2015-03-07

We introduce a new strategy for fabricating a seamless three-dimensional (3D) helical microreactor utilizing a silicone tube and a paraffin mold. With this method, various shapes and sizes of 3D helical microreactors were fabricated, and a complicated and laborious photolithographic process, or 3D printing, was eliminated. With dramatically enhanced portability at a significantly reduced fabrication cost, such a device can be considered to be the simplest microreactor, developed to date, for performing the flow-through polymerase chain reaction (PCR).

Innovative monitoring of 3D warp interlock fabric during forming process

NASA Astrophysics Data System (ADS)

Dufour, C.; Jerkovic, I.; Wang, P.; Boussu, F.; Koncar, V.; Soulat, D.; Grancaric, A. M.; Pineau, P.

2017-10-01

The final geometry of 3D warp interlock fabric needs to be check during the 3D forming step to ensure the right locations of warp and weft yarns inside the final structure. Thus, a new monitoring approach has been proposed based on sensor yarns located in the fabric thickness. To ensure the accuracy of measurements, the observation of the surface deformation of the 3D warp interlock fabric has been joined to the sensor yarns measurements. At the end, it has been revealed a good correlation between strain measurement done globally by camera and locally performed by sensor yarns.

Control of the interaction strength of photonic molecules by nanometer precise 3D fabrication.

PubMed

Rawlings, Colin D; Zientek, Michal; Spieser, Martin; Urbonas, Darius; Stöferle, Thilo; Mahrt, Rainer F; Lisunova, Yuliya; Brugger, Juergen; Duerig, Urs; Knoll, Armin W

2017-11-28

Applications for high resolution 3D profiles, so-called grayscale lithography, exist in diverse fields such as optics, nanofluidics and tribology. All of them require the fabrication of patterns with reliable absolute patterning depth independent of the substrate location and target materials. Here we present a complete patterning and pattern-transfer solution based on thermal scanning probe lithography (t-SPL) and dry etching. We demonstrate the fabrication of 3D profiles in silicon and silicon oxide with nanometer scale accuracy of absolute depth levels. An accuracy of less than 1nm standard deviation in t-SPL is achieved by providing an accurate physical model of the writing process to a model-based implementation of a closed-loop lithography process. For transfering the pattern to a target substrate we optimized the etch process and demonstrate linear amplification of grayscale patterns into silicon and silicon oxide with amplification ratios of ∼6 and ∼1, respectively. The performance of the entire process is demonstrated by manufacturing photonic molecules of desired interaction strength. Excellent agreement of fabricated and simulated structures has been achieved.

Fabrication and evaluation of advanced titanium structural panels for supersonic cruise aircraft

NASA Technical Reports Server (NTRS)

Payne, L.

1977-01-01

Flightworthy primary structural panels were designed, fabricated, and tested to investigate two advanced fabrication methods for titanium alloys. Skin-stringer panels fabricated using the weldbraze process, and honeycomb-core sandwich panels fabricated using a diffusion bonding process, were designed to replace an existing integrally stiffened shear panel on the upper wing surface of the NASA YF-12 research aircraft. The investigation included ground testing and Mach 3 flight testing of full-scale panels, and laboratory testing of representative structural element specimens. Test results obtained on full-scale panels and structural element specimens indicate that both of the fabrication methods investigated are suitable for primary structural applications on future civil and military supersonic cruise aircraft.

Fabrication of three-dimensional millimeter-height structures using direct ultraviolet lithography on liquid-state photoresist for simple and fast manufacturing

NASA Astrophysics Data System (ADS)

Kim, Jungkwun; Yoon, Yong-Kyu

2015-07-01

A rapid three-dimensional (3-D) ultraviolet (UV) lithography process for the fabrication of millimeter-tall high aspect ratio complex structures is presented. The liquid-state negative-tone photosensitive polyurethane, LF55GN, has been directly photopatterned using multidirectionally projected UV light for 3-D micropattern formation. The proposed lithographic scheme enabled us to overcome the maximum height obtained with a photopatternable epoxy, SU8, which has been conventionally most commonly used for the fabrication of tall and high aspect ratio microstructures. Also, the fabrication process time has been significantly reduced by eliminating photoresist-baking steps. Computer-controlled multidirectional UV lithography has been employed to fabricate 3-D structures, where the UV-exposure substrate is dynamically tilt-rotating during UV exposure to create various 3-D ray traces in the polyurethane layer. LF55GN has been characterized to provide feasible fabrication conditions for the multidirectional UV lithography. Very tall structures including a 6-mm tall triangular slab and a 5-mm tall hexablaze have been successfully fabricated. A 4.5-mm tall air-lifted polymer-core bowtie monopole antenna, which is the tallest monopole structure fabricated by photolithography and subsequent metallization, has been successfully demonstrated. The antenna shows a resonant radiation frequency of 12.34 GHz, a return loss of 36 dB, and a 10 dB bandwidth of 7%.

One-step direct-laser metal writing of sub-100 nm 3D silver nanostructures in a gelatin matrix

NASA Astrophysics Data System (ADS)

Kang, SeungYeon; Vora, Kevin; Mazur, Eric

2015-03-01

Developing an ability to fabricate high-resolution, 3D metal nanostructures in a stretchable 3D matrix is a critical step to realizing novel optoelectronic devices such as tunable bulk metal-dielectric optical devices and THz metamaterial devices that are not feasible with alternative techniques. We report a new chemistry method to fabricate high-resolution, 3D silver nanostructures using a femtosecond-laser direct metal writing technique. Previously, only fabrication of 3D polymeric structures or single-/few-layer metal structures was possible. Our method takes advantage of unique gelatin properties to overcome such previous limitations as limited freedom in 3D material design and short sample lifetime. We fabricate more than 15 layers of 3D silver nanostructures with a resolution of less than 100 nm in a stable dielectric matrix that is flexible and has high large transparency that is well-matched for potential applications in the optical and THz metamaterial regimes. This is a single-step process that does not require any further processing. This work will be of interest to those interested in fabrication methods that utilize nonlinear light-matter interactions and the realization of future metamaterials.

Fabricating optical phantoms to simulate skin tissue properties and microvasculatures

NASA Astrophysics Data System (ADS)

Sheng, Shuwei; Wu, Qiang; Han, Yilin; Dong, Erbao; Xu, Ronald

2015-03-01

This paper introduces novel methods to fabricate optical phantoms that simulate the morphologic, optical, and microvascular characteristics of skin tissue. The multi-layer skin-simulating phantom was fabricated by a light-cured 3D printer that mixed and printed the colorless light-curable ink with the absorption and the scattering ingredients for the designated optical properties. The simulated microvascular network was fabricated by a soft lithography process to embed microchannels in polydimethylsiloxane (PDMS) phantoms. The phantoms also simulated vascular anomalies and hypoxia commonly observed in cancer. A dual-modal multispectral and laser speckle imaging system was used for oxygen and perfusion imaging of the tissue-simulating phantoms. The light-cured 3D printing technique and the soft lithography process may enable freeform fabrication of skin-simulating phantoms that embed microvessels for image and drug delivery applications.

Process development for high-resolution 3D-printing of bioresorbable vascular stents

NASA Astrophysics Data System (ADS)

Ware, Henry Oliver T.; Farsheed, Adam C.; van Lith, Robert; Baker, Evan; Ameer, Guillermo; Sun, Cheng

2017-02-01

The recent development of "continuous projection microstereolithography" also known as CLIP technology has successfully alleviated the main obstacles surrounding 3D printing technologies: production speed and part quality. Following the same working principle, we further developed the μCLIP process to address the needs for high-resolution 3D printing of biomedical devices with micron-scale precision. Compared to standard stereolithography (SLA) process, μCLIP fabrication can reduce fabrication time from several hours to as little as a few minutes. μCLIP can also produce better surface finish and more uniform mechanical properties than conventional SLA, as each individual "fabrication layer" continuously polymerizes into the subsequent layer. In this study, we report the process development in manufacturing high-resolution bioresorbable stents using our own μCLIP system. The bioresorbable photopolymerizable biomaterial (B-ink) used in this study is methacrylated poly(1, 12 dodecamethylene citrate) (mPDC). Through optimization of our μCLIP process and concentration of B-ink components, we have created a customizable bioresorbable stent with similar mechanical properties exhibited by nitinol stents. Upon optimization, fabricating a 2 cm tall vascular stent that comprises 4000 layers was accomplished in 26.5 minutes.

Direct ink writing of 3D conductive polyaniline structures and rheological modelling

NASA Astrophysics Data System (ADS)

Holness, F. Benjamin; Price, Aaron D.

2018-01-01

The intractable nature of conjugated polymers (CP) leads to practical limitations in the fabrication of CP-based transducers having complex three-dimensional geometries. Conventional CP device fabrication processes have focused primarily on thin-film deposition techniques; this study explores novel additive manufacturing processes specifically developed for CP with the ultimate goal of increasing the functionality of CP sensors and actuators. Herein we employ automated polymer paste extrusion processes for the direct ink writing of 3D conductive polyaniline (PANI) structures. Realization of these structures was enabled through a modified fused filament fabrication delta robot equipped with an integrated polymer paste extruder to fabricate high-resolution 3D conductive PANI structures. The required processability of PANI was achieved by means of a counterion-induced thermal doping method. The effect of thermal doping on the PANI-DBSA paste by means of a constitutive relationship to describe the paste flow as a function of the thermal doping time is explored. This relationship is incorporated within a flow model to predict the extruded track width as a function of various process parameters including: print speed, gauge pressure, nozzle diameter, and pre-extrusion thermal doping time.

16 CFR 1605.3 - Compulsory processes and the service thereof.

Code of Federal Regulations, 2011 CFR

2011-01-01

.... 1605.3 Section 1605.3 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FLAMMABLE FABRICS ACT REGULATIONS INVESTIGATIONS, INSPECTIONS AND INQUIRIES PURSUANT TO THE FLAMMABLE FABRICS ACT Procedures for...) By personal service upon the person, or agent-in-charge of the sole proprietorship, partnership, or...

16 CFR 1605.3 - Compulsory processes and the service thereof.

Code of Federal Regulations, 2012 CFR

2012-01-01

.... 1605.3 Section 1605.3 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FLAMMABLE FABRICS ACT REGULATIONS INVESTIGATIONS, INSPECTIONS AND INQUIRIES PURSUANT TO THE FLAMMABLE FABRICS ACT Procedures for...) By personal service upon the person, or agent-in-charge of the sole proprietorship, partnership, or...

16 CFR 1605.3 - Compulsory processes and the service thereof.

Code of Federal Regulations, 2014 CFR

2014-01-01

.... 1605.3 Section 1605.3 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FLAMMABLE FABRICS ACT REGULATIONS INVESTIGATIONS, INSPECTIONS AND INQUIRIES PURSUANT TO THE FLAMMABLE FABRICS ACT Procedures for...) By personal service upon the person, or agent-in-charge of the sole proprietorship, partnership, or...

Fabrication Of SNS Weak Links On SOS Substrates

NASA Technical Reports Server (NTRS)

Hunt, Brian D.

1995-01-01

High-quality superconductor/normal-conductor/superconductor (SNS) devices ("weak links") containing epitaxial films of YBa(2)Cu(3)O(7-x) and SrTiO(3) fabricated on silicon-on-sapphire (SOS) substrates with help of improved multilayer buffer system. Process for fabrication of edge-defined SNS weak links described in "Edge-Geometry SNS Devices Made of Y/Ba/Cu" (NPO-18552).

3D scan line method for identifying void fabric of granular materials

NASA Astrophysics Data System (ADS)

Theocharis, Alexandros I.; Vairaktaris, Emmanouil; Dafalias, Yannis F.

2017-06-01

Among other processes measuring the void phase of porous or fractured media, scan line approach is a simplified "graphical" method, mainly used in image processing related procedures. In soil mechanics, the application of scan line method is related to the soil fabric, which is important in characterizing the anisotropic mechanical response of soils. Void fabric is of particular interest, since graphical approaches are well defined experimentally and most of them can also be easily used in numerical experiments, like the scan line method. This is in contrast to the definition of fabric based on contact normal vectors that are extremely difficult to determine, especially considering physical experiments. The scan line method has been proposed by Oda et al [1] and implemented again by Ghedia and O'Sullivan [2]. A modified method based on DEM analysis instead of image measurements of fabric has been previously proposed and implemented by the authors in a 2D scheme [3-4]. In this work, a 3D extension of the modified scan line definition is presented using PFC 3D®. The results show clearly similar trends with the 2D case and the same behaviour of fabric anisotropy is presented.

Silicon-based photonic crystals fabricated using proton beam writing combined with electrochemical etching method

PubMed Central

2012-01-01

A method for fabrication of three-dimensional (3D) silicon nanostructures based on selective formation of porous silicon using ion beam irradiation of bulk p-type silicon followed by electrochemical etching is shown. It opens a route towards the fabrication of two-dimensional (2D) and 3D silicon-based photonic crystals with high flexibility and industrial compatibility. In this work, we present the fabrication of 2D photonic lattice and photonic slab structures and propose a process for the fabrication of 3D woodpile photonic crystals based on this approach. Simulated results of photonic band structures for the fabricated 2D photonic crystals show the presence of TE or TM gap in mid-infrared range. PMID:22824206

Bile duct injury repair: when? what? who?

PubMed

Kapoor, Vinay K

2007-01-01

Laparoscopic cholecystectomy is associated with a two-to-four times higher risk of bile duct injury (BDI) than open cholecystectomy. BDI can lead to significant morbidity and even mortality. The first priority in BDI is to control peritoneal and biliary sepsis and to convert an acute BDI to a controlled external biliary fistula (EBF) - this can be achieved by endoscopic and/ or radiological intervention in most cases. This should be followed by assessment of the extent of injury - both biliary and vascular. Immediate management of BDI recognized during cholecystectomy depends on the type of injury, the condition of the patient, and the experience of the surgeon. For BDI recognized after cholecystectomy, early repair is not recommended, as the results are poor. The EBF may evolve into a benign biliary stricture (BBS), which should be electively repaired by a Roux-en-Y hepatico-jejunostomy. The use of an endoscopic stent as definitive management of BDI is not recommended. Long-term follow-up is essential after the repair of a BBS, as recurrence can occur several years after repair. Recurrent BBS is best treated with endoscopic balloon dilatation. Excellent early and long-term results can be obtained in specialized units at tertiary care referral centers.

Photon buildup factors of some chemotherapy drugs.

PubMed

Kavaz, Esra; Ahmadishadbad, Nader; Özdemir, Yüksel

2015-02-01

Everyday more and more people are diagnosed with some form of cancer. Some are treatable with chemotherapy alone, while others need radiotherapy and occasionally surgery. Recently, concurrent administration of chemotherapy and radiotherapy has been increasingly used in cancer treatment, leading to improvements in survival as well as quality of life. Accordingly, interaction of chemotherapy drugs with radiation will be meaningful to examine. In the present study, gamma ray energy absorption and exposure of buildup factors were computed using the five-parameter geometric progression (G-P) fitting formula for some chemotherapy drugs in the energy range 0.015-15 MeV, and for penetration depths up to 40 mean free path (mfp). The generated energy absorption (EABF) and exposure buildup factors (EBF) of chemotherapy drugs have been studied as a function of penetration depth and incident photon energy. The significant variations in EABF and EBF for chemotherapy drugs have been observed at the moderate energy region. It has been concluded that the buildup of photons is less in azathioprine and is more in vinblastine compared with other drugs. Buildup factors investigated in the present work could be useful in radiation dosimetry and therapy. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Applying a foil queue micro-electrode in micro-EDM to fabricate a 3D micro-structure

NASA Astrophysics Data System (ADS)

Xu, Bin; Guo, Kang; Wu, Xiao-yu; Lei, Jian-guo; Liang, Xiong; Guo, Deng-ji; Ma, Jiang; Cheng, Rong

2018-05-01

Applying a 3D micro-electrode in a micro electrical discharge machining (micro-EDM) can fabricate a 3D micro-structure with an up and down reciprocating method. However, this processing method has some shortcomings, such as a low success rate and a complex process for fabrication of 3D micro-electrodes. By focusing on these shortcomings, this paper proposed a novel 3D micro-EDM process based on the foil queue micro-electrode. Firstly, a 3D micro-electrode was discretized into several foil micro-electrodes and these foil micro-electrodes constituted a foil queue micro-electrode. Then, based on the planned process path, foil micro-electrodes were applied in micro-EDM sequentially and the micro-EDM results of each foil micro-electrode were able to superimpose the 3D micro-structure. However, the step effect will occur on the 3D micro-structure surface, which has an adverse effect on the 3D micro-structure. To tackle this problem, this paper proposes to reduce this adverse effect by rounded corner wear at the end of the foil micro-electrode and studies the impact of machining parameters on rounded corner wear and the step effect on the micro-structure surface. Finally, using a wire cutting voltage of 80 V, a current of 0.5 A and a pulse width modulation ratio of 1:4, the foil queue micro-electrode was fabricated by wire electrical discharge machining. Also, using a pulse width of 100 ns, a pulse interval of 200 ns, a voltage of 100 V and workpiece material of 304# stainless steel, the foil queue micro-electrode was applied in micro-EDM for processing of a 3D micro-structure with hemispherical features, which verified the feasibility of this process.

Fabrication of capsule assemblies, phase 3

NASA Technical Reports Server (NTRS)

Keeton, A. R.; Stemann, L. G.

1973-01-01

Thirteen capsule assemblies were fabricated for evaluation of fuel pin design concepts for a fast spectrum lithium cooled compact space power reactor. These instrumented assemblies were designed for real time test of prototype fuel pins. Uranium mononitride fuel pins were encased in AISI 304L stainless steel capsules. Fabrication procedures were fully qualified by process development and assembly qualification tests. Instrumentation reliability was achieved utilizing specially processed and closely controlled thermocouple hot zone fabrication and by thermal screening tests. Overall capsule reliability was achieved with an all electron beam welded assembly.

Enhancing the imaging quality and fabrication efficiency of bionic compound eyes using a sandwich structure

NASA Astrophysics Data System (ADS)

Luo, Jiasai; Guo, Yongcai; Wang, Xin

2018-06-01

This paper puts forward a novel method for fabrication of sandwich-structured BCE using a detachable micro-hole array (MHA) prepared by 3D printing. Compared with most traditional methods, 3D printing enables effective implementation of direct micro-fabrication for curved BCE without the pattern transfer and substrate reshaping process. This 3D fabrication method allows rapid fabrication of the curved BCE and automatic assembly of the detachable MHA using a custom-built mold under negative pressure. The formation of a multi-focusing micro-lens array (MLA) was realized by adjusting the parameters of the curved detachable MHA. The imaging performance was effectively enhanced by the sandwich structure that consist of the multi-focusing MLA, the outer detachable MHA and the inner solidified MHA. This method is suitable for mass production due to its advantages as a time-saving, cost-effective and simple process. Optical design software was used to analyze the optical properties, and an imaging simulation was performed.

On the Application of Rapid Prototyping Technology for the Fabrication of Flapping Wings for Micro Air Vehicles

NASA Astrophysics Data System (ADS)

Kraemer, Kurtis Leigh

Micro air vehicles (MAV) are a class of small uninhabited aircraft with dimensions less than 15 cm (6 in) and mass less than 500g (1.1 lbs). The aim of this research was to develop a fast, accurate, low-cost, and repeatable fabrication process for flapping MAV wings. Through the use of the RepRap Mendel open-source fused-deposition modeling (FDM) rapid prototyping machine ("3-D printer"), various wing prototypes were designed and fabricated using a bio-inspired approach. Testing of the aerodynamic performance of both real locust wings and the 3-D printed wing prototypes was performed through axial spin testing. Bending stiffness measurements were also performed on the 3-D printed wings. Through the use of open-source rapid prototyping technology, a fast and low-cost fabrication process for flapping MAV wings has been developed, out of which further understanding of flapping wing design and fabrication has been gained.

Roll-to-roll fabrication of large scale and regular arrays of three-dimensional nanospikes for high efficiency and flexible photovoltaics

PubMed Central

Leung, Siu-Fung; Gu, Leilei; Zhang, Qianpeng; Tsui, Kwong-Hoi; Shieh, Jia-Min; Shen, Chang-Hong; Hsiao, Tzu-Hsuan; Hsu, Chin-Hung; Lu, Linfeng; Li, Dongdong; Lin, Qingfeng; Fan, Zhiyong

2014-01-01

Three-dimensional (3-D) nanostructures have demonstrated enticing potency to boost performance of photovoltaic devices primarily owning to the improved photon capturing capability. Nevertheless, cost-effective and scalable fabrication of regular 3-D nanostructures with decent robustness and flexibility still remains as a challenging task. Meanwhile, establishing rational design guidelines for 3-D nanostructured solar cells with the balanced electrical and optical performance are of paramount importance and in urgent need. Herein, regular arrays of 3-D nanospikes (NSPs) were fabricated on flexible aluminum foil with a roll-to-roll compatible process. The NSPs have precisely controlled geometry and periodicity which allow systematic investigation on geometry dependent optical and electrical performance of the devices with experiments and modeling. Intriguingly, it has been discovered that the efficiency of an amorphous-Si (a-Si) photovoltaic device fabricated on NSPs can be improved by 43%, as compared to its planar counterpart, in an optimal case. Furthermore, large scale flexible NSP solar cell devices have been fabricated and demonstrated. These results not only have shed light on the design rules of high performance nanostructured solar cells, but also demonstrated a highly practical process to fabricate efficient solar panels with 3-D nanostructures, thus may have immediate impact on thin film photovoltaic industry. PMID:24603964

Roll-to-roll fabrication of large scale and regular arrays of three-dimensional nanospikes for high efficiency and flexible photovoltaics.

PubMed

Leung, Siu-Fung; Gu, Leilei; Zhang, Qianpeng; Tsui, Kwong-Hoi; Shieh, Jia-Min; Shen, Chang-Hong; Hsiao, Tzu-Hsuan; Hsu, Chin-Hung; Lu, Linfeng; Li, Dongdong; Lin, Qingfeng; Fan, Zhiyong

2014-03-07

Three-dimensional (3-D) nanostructures have demonstrated enticing potency to boost performance of photovoltaic devices primarily owning to the improved photon capturing capability. Nevertheless, cost-effective and scalable fabrication of regular 3-D nanostructures with decent robustness and flexibility still remains as a challenging task. Meanwhile, establishing rational design guidelines for 3-D nanostructured solar cells with the balanced electrical and optical performance are of paramount importance and in urgent need. Herein, regular arrays of 3-D nanospikes (NSPs) were fabricated on flexible aluminum foil with a roll-to-roll compatible process. The NSPs have precisely controlled geometry and periodicity which allow systematic investigation on geometry dependent optical and electrical performance of the devices with experiments and modeling. Intriguingly, it has been discovered that the efficiency of an amorphous-Si (a-Si) photovoltaic device fabricated on NSPs can be improved by 43%, as compared to its planar counterpart, in an optimal case. Furthermore, large scale flexible NSP solar cell devices have been fabricated and demonstrated. These results not only have shed light on the design rules of high performance nanostructured solar cells, but also demonstrated a highly practical process to fabricate efficient solar panels with 3-D nanostructures, thus may have immediate impact on thin film photovoltaic industry.

Electronic Devices Based on Oxide Thin Films Fabricated by Fiber-to-Film Process.

PubMed

Meng, You; Liu, Ao; Guo, Zidong; Liu, Guoxia; Shin, Byoungchul; Noh, Yong-Young; Fortunato, Elvira; Martins, Rodrigo; Shan, Fukai

2018-05-30

Technical development for thin-film fabrication is essential for emerging metal-oxide (MO) electronics. Although impressive progress has been achieved in fabricating MO thin films, the challenges still remain. Here, we report a versatile and general thermal-induced nanomelting technique for fabricating MO thin films from the fiber networks, briefly called fiber-to-film (FTF) process. The high quality of the FTF-processed MO thin films was confirmed by various investigations. The FTF process is generally applicable to numerous technologically relevant MO thin films, including semiconducting thin films (e.g., In 2 O 3 , InZnO, and InZrZnO), conducting thin films (e.g., InSnO), and insulating thin films (e.g., AlO x ). By optimizing the fabrication process, In 2 O 3 /AlO x thin-film transistors (TFTs) were successfully integrated by fully FTF processes. High-performance TFT was achieved with an average mobility of ∼25 cm 2 /(Vs), an on/off current ratio of ∼10 7 , a threshold voltage of ∼1 V, and a device yield of 100%. As a proof of concept, one-transistor-driven pixel circuit was constructed, which exhibited high controllability over the light-emitting diodes. Logic gates based on fully FTF-processed In 2 O 3 /AlO x TFTs were further realized, which exhibited good dynamic logic responses and voltage amplification by a factor of ∼4. The FTF technique presented here offers great potential in large-area and low-cost manufacturing for flexible oxide electronics.

Bismaleimide resins for flame resistant honeycomb sandwich panels

NASA Technical Reports Server (NTRS)

Stenzenberger, H. D.

1978-01-01

Bismaleimide resins are prime candidates for nonflammable aircraft interior panels. Three resin types with different structures and processing characteristics were formulated. Resin M 751 was used to fabricate 100 kg of glass fabric prepregs which were used for the preparation of face sheets for honeycomb sandwich panels. Prepreg characteristics and curing cycles for laminate fabrication are provided. In order to advance beyond the current solvent resin technology for fibre and fabric impregnation, a hot melt solvent-less resin system was prepared and characterized. Preliminary tests were performed to develop a wet bonding process for the fabrication of advanced sandwich honeycomb panels by use of polybismaleimide glass fabric face sheets and polybismaleimide Nomex honeycomb core. B-stage material was used for both the core and the face sheet, providing flatwise tensile properties equivalent to those obtained by the state-of-the-art 3-step process which includes an epoxy adhesive resin.

An investigation for the development of an integrated optical data preprocessor

NASA Technical Reports Server (NTRS)

Verber, C. M.; Vahey, D. W.; Kenan, R. P.; Wood, V. E.; Hartman, N. F.; Chapman, C. M.

1978-01-01

The successful fabrication and demonstration of an integrated optical circuit designed to perform a parallel processing operation by utilizing holographic subtraction to simultaneously compare N analog signal voltages with N predetermined reference voltages is summarized. The device alleviates transmission, storage and processing loads of satellite data systems by performing, at the sensor site, some preprocessing of data taken by remote sensors. Major accomplishments in the fabrication of integrated optics components include: (1) fabrication of the first LiNbO3 waveguide geodesic lens; (2) development of techniques for polishing TIR mirrors on LiNbO3 waveguides; (3) fabrication of high efficiency metal-over-photoresist gratings for waveguide beam splitters; (4) demonstration of high S/N holographic subtraction using waveguide holograms; and (5) development of alignment techniques for fabrication of integrated optics circuits. Important developments made in integrated optics are the discovery and suggested use of holographic self-subtraction in LiNbO3, development of a mathematical description of the operating modes of the preprocessor, and the development of theories for diffraction efficiency and beam quality of two dimensional beam defined gratings.

Light-driven 3D droplet manipulation on flexible optoelectrowetting devices fabricated by a simple spin-coating method.

PubMed

Jiang, Dongyue; Park, Sung-Yong

2016-05-21

Technical advances in electrowetting-on-dielectric (EWOD) over the past few years have extended our attraction to three-dimensional (3D) devices capable of providing more flexibility and functionality with larger volumetric capacity than conventional 2D planar ones. However, typical 3D EWOD devices require complex and expensive fabrication processes for patterning and wiring of pixelated electrodes that also restrict the minimum droplet size to be manipulated. Here, we present a flexible single-sided continuous optoelectrowetting (SCOEW) device which is not only fabricated by a spin-coating method without the need for patterning and wiring processes, but also enables light-driven 3D droplet manipulations. To provide photoconductive properties, previous optoelectrowetting (OEW) devices have used amorphous silicon (a-Si) typically fabricated through high-temperature processes over 300 °C such as CVD or PECVD. However, most of the commercially-available flexible substrates such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN) experience serious thermal deformation under such high-temperature processes. Because of this compatibility issue of conventional OEW devices with flexible substrates, light-driven 3D droplet manipulations have not yet been demonstrated on flexible substrates. Our study overcomes this compatibility issue by using a polymer-based photoconductive material, titanium oxide phthalocyanine (TiOPc) and thus SCOEW devices can be simply fabricated on flexible substrates through a low-cost, spin-coating method. In this paper, analytical studies were conducted to understand the effects of light patterns on static contact angles and EWOD forces. For experimental validations of our study, flexible SCOEW devices were successfully fabricated through the TiOPc-based spin-coating method and light-driven droplet manipulations (e.g. transportation, merging, and splitting) have been demonstrated on various 3D terrains such as inclined, vertical, upside-down, and curved surfaces. Our flexible SCOEW technology offers the benefits of device simplicity, flexibility, and functionality over conventional EWOD and OEW devices by enabling optical droplet manipulations on a 3D featureless surface.

Effectiveness and Appropriateness of mHealth Interventions for Maternal and Child Health: Systematic Review.

PubMed

Chen, Huan; Chai, Yanling; Dong, Le; Niu, Wenyi; Zhang, Puhong

2018-01-09

The application of mobile health (mHealth) technology in reproductive, maternal, newborn, and child health (RMNCH) is increasing worldwide. However, best practice and the most effective mHealth interventions have not been reviewed systematically. A systematic review and meta-analysis of studies of mHealth interventions for RMNCH around the world were conducted to investigate their characteristics as well as the features and effectiveness of mHealth interventions. Studies of mHealth interventions for RMNCH between January 2011 and December 2016 were retrieved from 6 databases (PubMed, EMBASE, Global Health, China National Knowledge Infrastructure, VIP Database for Chinese Technical Periodicals, and Wanfang Data Knowledge Service Medium). Comparable studies were included in a random-effects meta-analysis for both exclusive breastfeeding (EBF) and antenatal checks (ANC). Descriptive analyses were conducted for mHealth studies with a range of study designs. Analyses of 245 studies were included, including 51 randomized controlled trials (RCTs). Results showed that there are increasing numbers of studies on mHealth interventions for RMNCH. Although 2 meta-analysis, one with 2 RCTs on EBF (odds ratio [OR] 2.03, 95% CI 1.34-3.08, I 2 =25%) and the other with 3 RCTs on ANC (OR 1.43, 95% CI 1.13-1.79, I 2 =78%), showed that mHealth interventions are more effective than usual care, almost half (43%) of RCTs showed negative or unclear results on mHealth interventions. Functions described in mHealth interventions were diverse, and the health stages covered were broad. However, single function or single stage appeared to be dominant among mHealth interventions compared with multiple functions or stages. More rigorous evaluations are needed to draw consistent conclusions and to analyze mHealth products with multiple functions, especially those popular in the app markets. ©Huan Chen, Yanling Chai, Le Dong, Wenyi Niu, Puhong Zhang. Originally published in JMIR Mhealth and Uhealth (http://mhealth.jmir.org), 09.01.2018.

Effectiveness and Appropriateness of mHealth Interventions for Maternal and Child Health: Systematic Review

PubMed Central

Dong, Le; Niu, Wenyi

2018-01-01

Background The application of mobile health (mHealth) technology in reproductive, maternal, newborn, and child health (RMNCH) is increasing worldwide. However, best practice and the most effective mHealth interventions have not been reviewed systematically. Objective A systematic review and meta-analysis of studies of mHealth interventions for RMNCH around the world were conducted to investigate their characteristics as well as the features and effectiveness of mHealth interventions. Methods Studies of mHealth interventions for RMNCH between January 2011 and December 2016 were retrieved from 6 databases (PubMed, EMBASE, Global Health, China National Knowledge Infrastructure, VIP Database for Chinese Technical Periodicals, and Wanfang Data Knowledge Service Medium). Comparable studies were included in a random-effects meta-analysis for both exclusive breastfeeding (EBF) and antenatal checks (ANC). Descriptive analyses were conducted for mHealth studies with a range of study designs. Results Analyses of 245 studies were included, including 51 randomized controlled trials (RCTs). Results showed that there are increasing numbers of studies on mHealth interventions for RMNCH. Although 2 meta-analysis, one with 2 RCTs on EBF (odds ratio [OR] 2.03, 95% CI 1.34-3.08, I2=25%) and the other with 3 RCTs on ANC (OR 1.43, 95% CI 1.13-1.79, I2=78%), showed that mHealth interventions are more effective than usual care, almost half (43%) of RCTs showed negative or unclear results on mHealth interventions. Functions described in mHealth interventions were diverse, and the health stages covered were broad. However, single function or single stage appeared to be dominant among mHealth interventions compared with multiple functions or stages. Conclusions More rigorous evaluations are needed to draw consistent conclusions and to analyze mHealth products with multiple functions, especially those popular in the app markets. PMID:29317380

The miR-23a~27a~24-2 microRNA cluster buffers transcription and signaling pathways during hematopoiesis

PubMed Central

Kurkewich, Jeffrey L.; Klopfenstein, Nathan; Wood, Christian; Boucher, Austin

2017-01-01

MicroRNA cluster mirn23a has previously been shown to promote myeloid development at the expense of lymphoid development in overexpression and knockout mouse models. This polarization is observed early in hematopoietic development, with an increase in common lymphoid progenitors (CLPs) and a decrease in all myeloid progenitor subsets in adult bone marrow. The pool size of multipotential progenitors (MPPs) is unchanged; however, in this report we observe by flow cytometry that polarized subsets of MPPs are changed in the absence of mirn23a. Additionally, in vitro culture of MPPs and sorted MPP transplants showed that these cells have decreased myeloid and increased lymphoid potential in vitro and in vivo. We investigated the mechanism by which mirn23a regulates hematopoietic differentiation and observed that mirn23a promotes myeloid development of hematopoietic progenitors through regulation of hematopoietic transcription factors and signaling pathways. Early transcription factors that direct the commitment of MPPs to CLPs (Ikzf1, Runx1, Satb1, Bach1 and Bach2) are increased in the absence of mirn23a miRNAs as well as factors that commit the CLP to the B cell lineage (FoxO1, Ebf1, and Pax5). Mirn23a appears to buffer transcription factor levels so that they do not stochastically reach a threshold level to direct differentiation. Intriguingly, mirn23a also inversely regulates the PI3 kinase (PI3K)/Akt and BMP/Smad signaling pathways. Pharmacological inhibitor studies, coupled with dominant active/dominant negative biochemical experiments, show that both signaling pathways are critical to mirn23a’s regulation of hematopoietic differentiation. Lastly, consistent with mirn23a being a physiological inhibitor of B cell development, we observed that the essential B cell transcription factor EBF1 represses expression of mirn23a. In summary, our data demonstrates that mirn23a regulates a complex array of transcription and signaling pathways to modulate adult hematopoiesis. PMID:28704388

Highly Controlled Codeposition Rate of Organolead Halide Perovskite by Laser Evaporation Method.

PubMed

Miyadera, Tetsuhiko; Sugita, Takeshi; Tampo, Hitoshi; Matsubara, Koji; Chikamatsu, Masayuki

2016-10-05

Organolead-halide perovskites can be promising materials for next-generation solar cells because of its high power conversion efficiency. The method of precise fabrication is required because both solution-process and vacuum-process fabrication of the perovskite have problems of controllability and reproducibility. Vacuum deposition process was expected to achieve precise control; however, vaporization of amine compound significantly degrades the controllability of deposition rate. Here we achieved the reduction of the vaporization by implementing the laser evaporation system for the codeposition of perovskite. Locally irradiated continuous-wave lasers on the source materials realized the reduced vaporization of CH 3 NH 3 I. The deposition rate was stabilized for several hours by adjusting the duty ratio of modulated laser based on proportional-integral control. Organic-photovoltaic-type perovskite solar cells were fabricated by codeposition of PbI 2 and CH 3 NH 3 I. A power-conversion efficiency of 16.0% with reduced hysteresis was achieved.

Isolation and recovery of cellulose from waste nylon/cotton blended fabrics by 1-allyl-3-methylimidazolium chloride.

PubMed

Lv, Fangbing; Wang, Chaoxia; Zhu, Ping; Zhang, Chuanjie

2015-06-05

Development of a simple process for separating cellulose and nylon 6 from their blended fabrics is indispensable for recycling of waste mixed fabrics. An efficient procedure of dissolution of the fabrics in an ionic liquid 1-allyl-3-methylimidazolium chloride ([AMIM]Cl) and subsequent filtration separation has been demonstrated. Effects of treatment temperature, time and waste fabrics ratio on the recovery rates were investigated. SEM images showed that the cotton cellulose dissolved in [AMIM]Cl while the nylon 6 fibers remained. The FTIR spectrum of regenerated cellulose (RC) was similar with that of virgin cotton fibers, which verified that no other chemical reaction occurred besides breakage of hydrogen bonds during the processes of dissolution and separation. TGA curves indicated that the regenerated cellulose possessed a reduced thermal stability and was effectively removed from waste nylon/cotton blended fabrics (WNCFs). WNCFs were sufficiently reclaimed with high recovery rate of both regenerated cellulose films and nylon 6 fibers. Copyright © 2015 Elsevier Ltd. All rights reserved.

Progress on BN and Doped-BN Coatings on Woven Fabrics

NASA Technical Reports Server (NTRS)

Hurwitz, Frances I.; Scott, John M.; Chayka, Paul V.

2001-01-01

A novel, multistep process for applying interface coatings to woven structures using a pulsed CVD process is being evaluated. Borazine (B3N3H6), a neat liquid, and several Si precursors are used in the process to produce BN and SiBN coatings on Hi- Nicalon fabrics and preforms. A three variable, two level, full factorial matrix is proposed to define the influence of processing parameters. Coating morphology, uniformity and chemistry are characterized by field emission scanning electron microscopy (FESEM), energy dispersive (EDS) and Auger spectroscopies.

Fabrication of lightweight Si/SiC LIDAR mirrors

NASA Technical Reports Server (NTRS)

Goela, Jitendra S.; Taylor, Raymond L.

1991-01-01

A new, chemical vapor deposition (CVD) process was developed for fabricating lightweight, polycrystalline silicon/silicon-carbide (Si/SiC) mirrors. The process involves three CVD steps: (1) to produce the mirror faceplate; (2) to form the lightweight backstructure, which is deposited integral to the faceplate; and (3) to deposit a layer of optical-grade material, e.g., Si, onto the front surface of the faceplate. The mirror figure and finish are fabricated into the faceplate.

Design of fabric preforms for double diaphragm forming

NASA Technical Reports Server (NTRS)

Luby, Steven; Bernardon, Edward

1992-01-01

Resin Transfer Molding (RTM) has the potential of becoming one of the most cost effective ways of producing composite structures since the raw materials used, resin and dry fabric, are less costly than prepregs. Unfortunately these low material costs are offset by the high labor costs incurred to layup the dry fabric into 3D shapes. To reduce the layup costs, double diaphragm forming is being investigated as a potential technique for creating a complex 3D preform from a simple flat layup. As part of our effort to develop double diaphragm forming into a production capable process, we have undertaken a series of experiments to investigate the interactions between process parameters, mold geometry, fabric weave, tow size, and the quality of the formed part. The results of these tests will be used to determine the forming geometry limitations of double diaphragm forming and to characterize the formability of fabric configurations. An important part of this work was the development of methods to measure and analyze fiber orientations, deformation angles, tow spreading, and shape conformation of the formed parts. This paper will describe the methods used to mark plies, the double diaphragm forming process, the techniques used to measure the formed parts, and the calculation of the parameters of interest. The results can be displayed as 3D contour plots. These experimental results have also been used to verify and improve a computer model which simulates the draping of fabrics over 3D mold shapes.

16 CFR § 1605.3 - Compulsory processes and the service thereof.

Code of Federal Regulations, 2013 CFR

2013-01-01

.... § 1605.3 Section § 1605.3 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FLAMMABLE FABRICS ACT REGULATIONS INVESTIGATIONS, INSPECTIONS AND INQUIRIES PURSUANT TO THE FLAMMABLE FABRICS ACT... effected as follows: (1) By personal service upon the person, or agent-in-charge of the sole proprietorship...

Conflict or congruence? Maternal and infant-centric factors associated with shorter exclusive breastfeeding durations among the Tsimane

PubMed Central

Martin, Melanie A.; Garcia, Geni; Kaplan, Hillard S.; Gurven, Michael D.

2016-01-01

Six months of exclusive breastfeeding (EBF) is considered optimal for infant health, though globally most infants begin complementary feeding (CF) earlier—including among populations that practice prolonged breastfeeding. Two frameworks for understanding patterns of early CF emerge in the literature. In the first, maternal and infant needs trade-off, as “maternal-centric” factors—related to time and energy demands, reproductive investment, cultural influences, and structural barriers— favor supplanting breastfeeding with earlier and increased CF. A second framework considers that “infant-centric” factors—related to infant energetic needs—favor CF before six months to supplement breastfeeding. We apply these two frameworks in examining early CF among the Tsimane—a high-fertility, high-mortality, forager-horticulturalist population residing in the Bolivian Amazon. Data were collected from a mixed-longitudinal sample of 161 Tsimane mother-infant pairs from August 2012 – April 2013. Tsimane mothers generally reported introducing CF because of perceived infant needs. However, CF is introduced with continued intensive breastfeeding, and generally coupled with premastication. Risks of earlier CF relative to the minimum hazard (estimated at 5 births) were elevated for lower and higher parity mothers, but were significantly greater only after 9 births. Seventeen percent of mothers reported introducing CF because of low milk supply. Introducing CF because of low milk was most common from 0-3 months of age and among higher parity mothers, which may reflect physiological constraints. Maternal reproductive trade-offs and perceived infant needs may help explain the low prevalence of EBF to six months among other populations in which breastfeeding is not structurally or culturally constrained. PMID:27732906

Numerical investigation of the effects of channel geometry on platelet activation and blood damage.

PubMed

Wu, Jingshu; Yun, B Min; Fallon, Anna M; Hanson, Stephen R; Aidun, Cyrus K; Yoganathan, Ajit P

2011-02-01

Thromboembolic complications in Bileaflet mechanical heart valves (BMHVs) are believed to be due to the combination of high shear stresses and large recirculation regions. Relating blood damage to design geometry is therefore essential to ultimately optimize the design of BMHVs. The aim of this research is to quantitatively study the effect of 3D channel geometry on shear-induced platelet activation and aggregation, and to choose an appropriate blood damage index (BDI) model for future numerical simulations. The simulations in this study use a recently developed lattice-Boltzmann with external boundary force (LBM-EBF) method [Wu, J., and C. K. Aidun. Int. J. Numer. Method Fluids 62(7):765-783, 2010; Wu, J., and C. K. Aidun. Int. J. Multiphase flow 36:202-209, 2010]. The channel geometries and flow conditions are re-constructed from recent experiments by Fallon [The Development of a Novel in vitro Flow System to Evaluate Platelet Activation and Procoagulant Potential Induced by Bileaflet Mechanical Heart Valve Leakage Jets in School of Chemical and Biomolecular Engineering. Atlanta: Georgia Institute of Technology] and Fallon et al. [Ann. Biomed. Eng. 36(1):1]. The fluid flow is computed on a fixed regular 'lattice' using the LBM, and each platelet is mapped onto a Lagrangian frame moving continuously throughout the fluid domain. The two-way fluid-solid interactions are determined by the EBF method by enforcing a no-slip condition on the platelet surface. The motion and orientation of the platelet are obtained from Newtonian dynamics equations. The numerical results show that sharp corners or sudden shape transitions will increase blood damage. Fallon's experimental results were used as a basis for choosing the appropriate BDI model for use in future computational simulations of flow through BMHVs.

Recommendations for Infant Feeding Policy and Programs in Dzimauli Region, South Africa: Results From the MAL-ED Birth Cohort

PubMed Central

Mushaphi, Lindelani Fhumudzani; Mahopo, Tjale Cloupas; Nesamvuni, Cebisa Noxolo; Baloyi, Brenda; Mashau, Ellen; Richardson, Jeniata; Dillingham, Rebecca; Guerrant, Richard; Ambikapathi, Ramya; Bessong, Pascal

2018-01-01

Background There is strong evidence that exclusive breastfeeding (EBF) in the first 6 months of life reduces the risk of diseases in infancy and in later life. Objective To understand the maternal reasoning that influences optimum infant feeding practices of caregivers in semirural communities of Limpopo province. Methods Nested qualitative study among mothers in an ongoing birth cohort study was conducted; structured and semi-structured interviews were used to collect data. Data from 234 infants after 6 months of follow-up was included for quantitative analysis. Four focus discussion groups comprising 7 to 10 caregivers were used to obtain perception of mothers on breastfeeding. A semi-structured interview guide was used to stimulate discussions. Thematic content analyses were conducted to identify the main themes that influence breastfeeding practices of caregivers. Results Over 90% of the caregivers initiated breastfeeding after delivery. However, less than 1% of mothers practiced EBF by 3 months, and none of the children were exclusively breastfed for up to 6 months. All caregivers introduced non–breast milk liquids and solids by the second month of child’s life. Common reasons for introducing non–breast milk foods included insufficiency of breast milk production, going back to work or school, and influence by elderly women (mothers/mothers-in-law) and church members. Conclusion Exclusive breastfeeding was not practiced in this community due to cultural and religious beliefs and misinformation. The involvement of elderly women and church members in infant feeding education and promotion programs and the dissemination of breastfeeding information through mobile phones to younger mothers are recommended. PMID:28958169

Cost of individual peer counselling for the promotion of exclusive breastfeeding in Uganda

PubMed Central

2011-01-01

Background Exclusive breastfeeding (EBF) for 6 months is the recommended form of infant feeding. Support of mothers through individual peer counselling has been proved to be effective in increasing exclusive breastfeeding prevalence. We present a costing study of an individual peer support intervention in Uganda, whose objective was to raise exclusive breastfeeding rates at 3 months of age. Methods We costed the peer support intervention, which was offered to 406 breastfeeding mothers in Uganda. The average number of counselling visits was about 6 per woman. Annual financial and economic costs were collected in 2005-2008. Estimates were made of total project costs, average costs per mother counselled and average costs per peer counselling visit. Alternative intervention packages were explored in the sensitivity analysis. We also estimated the resources required to fund the scale up to district level, of a breastfeeding intervention programme within a public health sector model. Results Annual project costs were estimated to be US$56,308. The largest cost component was peer supporter supervision, which accounted for over 50% of total project costs. The cost per mother counselled was US$139 and the cost per visit was US$26. The cost per week of EBF was estimated to be US$15 at 12 weeks post partum. We estimated that implementing an alternative package modelled on routine public health sector programmes can potentially reduce costs by over 60%. Based on the calculated average costs and annual births, scaling up modelled costs to district level would cost the public sector an additional US$1,813,000. Conclusion Exclusive breastfeeding promotion in sub-Saharan Africa is feasible and can be implemented at a sustainable cost. The results of this study can be incorporated in cost effectiveness analyses of exclusive breastfeeding promotion programmes in sub-Saharan Africa. PMID:21714877

SpaRibs Geometry Parameterization for Wings with Multiple Sections using Single Design

NASA Technical Reports Server (NTRS)

De, Shuvodeep; Jrad, Mohamed; Locatelli, Davide; Kapania, Rakesh K.; Baker, Myles; Pak, Chan-Gi

2017-01-01

The SpaRibs topology of an aircraft wing has a significant effect on its structural behavior and stability as well as the flutter performance. The development of additive manufacturing techniques like Electron Beam Free Form Fabrication (EBF3) has made it feasible to manufacture aircraft wings with curvilinear spars, ribs (SpaRibs) and stiffeners. In this article a new global-local optimization framework for wing with multiple sections using curvilinear SpaRibs is described. A single design space is used to parameterize the SpaRibs geometry. This method has been implemented using MSC-PATRAN to create a broad range of SpaRibs topologies using limited number of parameters. It ensures C0 and C1 continuities in SpaRibs geometry at the junction of two wing sections with airfoil thickness gradient discontinuity as well as mesh continuity between all structural components. This method is advantageous in complex multi-disciplinary optimization due to its potential to reduce the number of design variables. For the global-local optimization the local panels are generated by an algorithm which is totally based on a set algebra on the connectivity matrix data. The great advantage of this method is that it is completely independent of the coordinates of the nodes of the finite element model. It is also independent of the order in which the elements are distributed in the FEM. The code is verified by optimizing of the CRM Baseline model at trim condition at Mach number equal to 0.85 for five different angle of attack (-2deg, 0deg,2deg,4deg and 6deg). The final weight of the wing is 19,090.61 lb. This value is comparable to that obtained by Qiang et al. 6 (19,269 lb).

Affective assessment of computer users based on processing the pupil diameter signal.

PubMed

Ren, Peng; Barreto, Armando; Gao, Ying; Adjouadi, Malek

2011-01-01

Detecting affective changes of computer users is a current challenge in human-computer interaction which is being addressed with the help of biomedical engineering concepts. This article presents a new approach to recognize the affective state ("relaxation" vs. "stress") of a computer user from analysis of his/her pupil diameter variations caused by sympathetic activation. Wavelet denoising and Kalman filtering methods are first used to remove abrupt changes in the raw Pupil Diameter (PD) signal. Then three features are extracted from the preprocessed PD signal for the affective state classification. Finally, a random tree classifier is implemented, achieving an accuracy of 86.78%. In these experiments the Eye Blink Frequency (EBF), is also recorded and used for affective state classification, but the results show that the PD is a more promising physiological signal for affective assessment.

Development and Optimization of Silver Nanoparticle Formulation for Fabrication

DTIC Science & Technology

2015-08-14

Development and Optimization of Silver Nanoparticle Formulation for Fabrication Publication Type: DJournal/ Paper D Book Chapter ~ Tech Report D...leofPublicationorPresentation: Deve l opment and Optimization of Silver Nanoparticle Formulation for Fabrication 3. Author(s): (List authors starting...fabrication process of silver nanoparticl es could improve future silver containing products , which is i mpor tant to l owering toxicity and improving

One-Step Printable Perovskite Films Fabricated under Ambient Conditions for Efficient and Reproducible Solar Cells.

PubMed

Jung, Yen-Sook; Hwang, Kyeongil; Heo, Youn-Jung; Kim, Jueng-Eun; Lee, Donmin; Lee, Cheol-Ho; Joh, Han-Ik; Yeo, Jun-Seok; Kim, Dong-Yu

2017-08-23

Despite the potential of roll-to-roll processing for the fabrication of perovskite films, the realization of highly efficient and reproducible perovskite solar cells (PeSCs) through continuous coating techniques and low-temperature processing is still challenging. Here, we demonstrate that efficient and reliable CH 3 NH 3 PbI 3 (MAPbI 3 ) films fabricated by a printing process can be achieved through synergetic effects of binary processing additives, N-cyclohexyl-2-pyrrolidone (CHP) and dimethyl sulfoxide (DMSO). Notably, these perovskite films are deposited from premixed perovskite solutions for facile one-step processing under a room-temperature and ambient atmosphere. The CHP molecules result in the uniform and homogeneous perovskite films even in the one-step slot-die system, which originate from the high boiling point and low vapor pressure of CHP. Meanwhile, the DMSO molecules facilitate the growth of perovskite grains by forming intermediate states with the perovskite precursor molecules. Consequently, fully printed PeSC based on the binary additive system exhibits a high PCE of 12.56% with a high reproducibility.

Fabrication and mechanical characterization of long and different penetrating length neural microelectrode arrays

NASA Astrophysics Data System (ADS)

Goncalves, S. B.; Peixoto, A. C.; Silva, A. F.; Correia, J. H.

2015-05-01

This paper presents a detailed description of the design, fabrication and mechanical characterization of 3D microelectrode arrays (MEA) that comprise high aspect-ratio shafts and different penetrating lengths of electrodes (from 3 mm to 4 mm). The array’s design relies only on a bulk silicon substrate dicing saw technology. The encapsulation process is accomplished by a medical epoxy resin and platinum is used as the transduction layer between the probe and neural tissue. The probe’s mechanical behaviour can significantly affect the neural tissue during implantation time. Thus, we measured the MEA maximum insertion force in an agar gel phantom and a porcine cadaver brain. Successful 3D MEA were produced with shafts of 3 mm, 3.5 mm and 4 mm in length. At a speed of 180 mm min-1, the MEA show maximum penetrating forces per electrode of 2.65 mN and 12.5 mN for agar and brain tissue, respectively. A simple and reproducible fabrication method was demonstrated, capable of producing longer penetrating shafts than previously reported arrays using the same fabrication technology. Furthermore, shafts with sharp tips were achieved in the fabrication process simply by using a V-shaped blade.

Direct single-layered fabrication of 3D concavo convex patterns in nano-stereolithography

NASA Astrophysics Data System (ADS)

Lim, T. W.; Park, S. H.; Yang, D. Y.; Kong, H. J.; Lee, K. S.

2006-09-01

A nano-surfacing process (NSP) is proposed to directly fabricate three-dimensional (3D) concavo convex-shaped microstructures such as micro-lens arrays using two-photon polymerization (TPP), a promising technique for fabricating arbitrary 3D highly functional micro-devices. In TPP, commonly utilized methods for fabricating complex 3D microstructures to date are based on a layer-by-layer accumulating technique employing two-dimensional sliced data derived from 3D computer-aided design data. As such, this approach requires much time and effort for precise fabrication. In this work, a novel single-layer exposure method is proposed in order to improve the fabricating efficiency for 3D concavo convex-shaped microstructures. In the NSP, 3D microstructures are divided into 13 sub-regions horizontally with consideration of the heights. Those sub-regions are then expressed as 13 characteristic colors, after which a multi-voxel matrix (MVM) is composed with the characteristic colors. Voxels with various heights and diameters are generated to construct 3D structures using a MVM scanning method. Some 3D concavo convex-shaped microstructures were fabricated to estimate the usefulness of the NSP, and the results show that it readily enables the fabrication of single-layered 3D microstructures.

Large arrays of dual-polarized multichroic TES detectors for CMB measurements with the SPT-3G receiver

DOE PAGES

Holland, Wayne S.; Zmuidzinas, Jonas; Posada, Chrystian M.; ...

2016-07-19

Now, detectors for cosmic microwave background (CMB) experiments are background limited, so a straightforward alternative to improve sensitivity is to increase the number of detectors. Large arrays of multichroic pixels constitute an economical approach to increasing the number of detectors within a given focal plane area. We present the fabrication of large arrays of dual-polarized multichroic transition-edge-sensor (TES) bolometers for the South Pole Telescope third-generation CMB receiver (SPT-3G). The complete SPT-3G receiver will have 2690 pixels, each with six detectors, allowing for individual measurement of three spectral bands (centered at 95 GHz, 150 GHz and 220 GHz) in two orthogonalmore » polarizations. In total, the SPT-3G focal plane will have 16140 detectors. Each pixel is comprised of a broad-band sinuous antenna coupled to a niobium microstrip transmission line. In-line filters are used to define the different band-passes before the millimeter-wavelength signal is fed to the respective Ti/Au TES sensors. Detectors are read out using a 64x frequency domain multiplexing (fMux) scheme. The microfabrication of the SPT-3G detector arrays involves a total of 18 processes, including 13 lithography steps. Together with the fabrication process, the effect of processing on the Ti/Au TES's T-c is discussed. In addition, detectors fabricated with Ti/Au TES films with Tc between 400 mK 560 mK are presented and their thermal characteristics are evaluated. Optical characterization of the arrays is presented as well, indicating that the response of the detectors is in good agreement with the design values for all three spectral bands (95 GHz, 150 GHz, and 220 GHz). The measured optical efficiency of the detectors is between 0.3 and 0.8. Our results discussed here are extracted from a batch of research of development wafers used to develop the baseline process for the fabrication of the arrays of detectors to be deployed with the SPT-3G receiver. Results from these research and development wafers have been incorporated into the fabrication process to get the baseline fabrication process presented here. SPT-3G is scheduled to deploy to the South Pole Telescope in late 2016.« less

Large arrays of dual-polarized multichroic TES detectors for CMB measurements with the SPT-3G receiver

DOE Office of Scientific and Technical Information (OSTI.GOV)

Holland, Wayne S.; Zmuidzinas, Jonas; Posada, Chrystian M.

Now, detectors for cosmic microwave background (CMB) experiments are background limited, so a straightforward alternative to improve sensitivity is to increase the number of detectors. Large arrays of multichroic pixels constitute an economical approach to increasing the number of detectors within a given focal plane area. We present the fabrication of large arrays of dual-polarized multichroic transition-edge-sensor (TES) bolometers for the South Pole Telescope third-generation CMB receiver (SPT-3G). The complete SPT-3G receiver will have 2690 pixels, each with six detectors, allowing for individual measurement of three spectral bands (centered at 95 GHz, 150 GHz and 220 GHz) in two orthogonalmore » polarizations. In total, the SPT-3G focal plane will have 16140 detectors. Each pixel is comprised of a broad-band sinuous antenna coupled to a niobium microstrip transmission line. In-line filters are used to define the different band-passes before the millimeter-wavelength signal is fed to the respective Ti/Au TES sensors. Detectors are read out using a 64x frequency domain multiplexing (fMux) scheme. The microfabrication of the SPT-3G detector arrays involves a total of 18 processes, including 13 lithography steps. Together with the fabrication process, the effect of processing on the Ti/Au TES's T-c is discussed. In addition, detectors fabricated with Ti/Au TES films with Tc between 400 mK 560 mK are presented and their thermal characteristics are evaluated. Optical characterization of the arrays is presented as well, indicating that the response of the detectors is in good agreement with the design values for all three spectral bands (95 GHz, 150 GHz, and 220 GHz). The measured optical efficiency of the detectors is between 0.3 and 0.8. Our results discussed here are extracted from a batch of research of development wafers used to develop the baseline process for the fabrication of the arrays of detectors to be deployed with the SPT-3G receiver. Results from these research and development wafers have been incorporated into the fabrication process to get the baseline fabrication process presented here. SPT-3G is scheduled to deploy to the South Pole Telescope in late 2016.« less

Large arrays of dual-polarized multichroic TES detectors for CMB measurements with the SPT-3G receiver

NASA Astrophysics Data System (ADS)

Posada, Chrystian M.; Ade, Peter A. R.; Anderson, Adam J.; Avva, Jessica; Ahmed, Zeeshan; Arnold, Kam S.; Austermann, Jason; Bender, Amy N.; Benson, Bradford A.; Bleem, Lindsey; Byrum, Karen; Carlstrom, John E.; Carter, Faustin W.; Chang, Clarence; Cho, Hsiao-Mei; Cukierman, Ari; Czaplewski, David A.; Ding, Junjia; Divan, Ralu N. S.; de Haan, Tijmen; Dobbs, Matt; Dutcher, Daniel; Everett, Wenderline; Gannon, Renae N.; Guyser, Robert J.; Halverson, Nils W.; Harrington, Nicholas L.; Hattori, Kaori; Henning, Jason W.; Hilton, Gene C.; Holzapfel, William L.; Huang, Nicholas; Irwin, Kent D.; Jeong, Oliver; Khaire, Trupti; Korman, Milo; Kubik, Donna L.; Kuo, Chao-Lin; Lee, Adrian T.; Leitch, Erik M.; Lendinez Escudero, Sergi; Meyer, Stephan S.; Miller, Christina S.; Montgomery, Joshua; Nadolski, Andrew; Natoli, Tyler J.; Nguyen, Hogan; Novosad, Valentyn; Padin, Stephen; Pan, Zhaodi; Pearson, John E.; Rahlin, Alexandra; Reichardt, Christian L.; Ruhl, John E.; Saliwanchik, Benjamin; Shirley, Ian; Sayre, James T.; Shariff, Jamil A.; Shirokoff, Erik D.; Stan, Liliana; Stark, Antony A.; Sobrin, Joshua; Story, Kyle; Suzuki, Aritoki; Tang, Qing Yang; Thakur, Ritoban B.; Thompson, Keith L.; Tucker, Carole E.; Vanderlinde, Keith; Vieira, Joaquin D.; Wang, Gensheng; Whitehorn, Nathan; Yefremenko, Volodymyr; Yoon, Ki Won

2016-07-01

Detectors for cosmic microwave background (CMB) experiments are now essentially background limited, so a straightforward alternative to improve sensitivity is to increase the number of detectors. Large arrays of multichroic pixels constitute an economical approach to increasing the number of detectors within a given focal plane area. Here, we present the fabrication of large arrays of dual-polarized multichroic transition-edge-sensor (TES) bolometers for the South Pole Telescope third-generation CMB receiver (SPT-3G). The complete SPT-3G receiver will have 2690 pixels, each with six detectors, allowing for individual measurement of three spectral bands (centered at 95 GHz, 150 GHz and 220 GHz) in two orthogonal polarizations. In total, the SPT-3G focal plane will have 16140 detectors. Each pixel is comprised of a broad-band sinuous antenna coupled to a niobium microstrip transmission line. In-line filters are used to define the different band-passes before the millimeter-wavelength signal is fed to the respective Ti/Au TES sensors. Detectors are read out using a 64x frequency domain multiplexing (fMux) scheme. The microfabrication of the SPT-3G detector arrays involves a total of 18 processes, including 13 lithography steps. Together with the fabrication process, the effect of processing on the Ti/Au TES's Tc is discussed. In addition, detectors fabricated with Ti/Au TES films with Tc between 400 mK 560 mK are presented and their thermal characteristics are evaluated. Optical characterization of the arrays is presented as well, indicating that the response of the detectors is in good agreement with the design values for all three spectral bands (95 GHz, 150 GHz, and 220 GHz). The measured optical efficiency of the detectors is between 0.3 and 0.8. Results discussed here are extracted from a batch of research of development wafers used to develop the baseline process for the fabrication of the arrays of detectors to be deployed with the SPT-3G receiver. Results from these research and development wafers have been incorporated into the fabrication process to get the baseline fabrication process presented here. SPT-3G is scheduled to deploy to the South Pole Telescope in late 2016.

Toward mass producible ordered bulk heterojunction organic photovoltaic devices.

PubMed

Kim, Taeyong; Yoon, Hyunsik; Song, Hyung-Jun; Haberkorn, Niko; Cho, Younghyun; Sung, Seung Hyun; Lee, Chang Hee; Char, Kookheon; Theato, Patrick

2012-12-13

A strategy to fabricate nanostructured poly(3-hexylthiophene) (P3HT) films for organic photovoltaic (OPV) cells by a direct transfer method from a reusable soft replica mold is presented. The flexible polyfluoropolyether (PFPE) replica mold allows low-pressure and low- temperature process condition for the successful transfer of nanostructured P3HT films onto PEDOT/PSS-coated ITO substrates. To reduce the fabrication cost of masters in large area, we employed well-ordered anodic aluminum oxide (AAO) as a template. Also, we provide a method to fabricate reversed nanostructures by exploiting the self-replication of replica molds. The concept of the transfer method in low temperature with a flexible and reusable replica mold obtained from an AAO template will be a firm foundation for a low-cost fabrication process of ordered OPVs. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Fabrication of fine-grain tantalum diffusion barrier tube for Nb3Sn conductors

NASA Astrophysics Data System (ADS)

Hartwig, K. T.; Balachandran, S.; Mezyenski, R.; Seymour, N.; Robinson, J.; Barber, R. E.

2014-01-01

Diffusion barriers used in Nb3Sn wire are often fabricated by wrapping Ta sheet into a tube with an overlap seam. A common result of such practice is non-uniform deformation in the Ta sheet as it thins by wire drawing because of non-uniform grain size and texture in the original Ta sheet. Seamless Ta tube with a fine-grain and uniform microstructure would be much better for the diffusion barrier application, but such material is expensive and difficult to manufacture. This report presents results on a new fabrication strategy for Ta tube that shows promise for manufacture of less costly tube with an improved microstructure. The fabrication method begins with seam-welded tube but gives a fine-grain uniform microstructure with little difference between the longitudinal seam weld region and the parent metal after post-weld processing. Severe plastic deformation processing (SPD) applied by area reduction extrusion and tube equal channel angular extrusion (tECAE) are used to refine and homogenize the microstructure. Microstructure and mechanical property results are presented for Ta tubes fabricated by this new processing strategy.

B cell signatures of BCWD-resistant and susceptible lines of rainbow trout: a shift towards more EBF-expressing progenitors and fewer mature B cells in resistant animals

USDA-ARS?s Scientific Manuscript database

Bacterial Cold Water Disease (BCWD) is a chronic disease of rainbow trout, and is caused by the gram-negative bacterium Flavobacterium psychrophilum (Fp), a common aquaculture pathogen. The National Center for Cool and Cold Water Aquaculture has bred two genetic lines of rainbow trout: a line of Fp...

B cell signatures of BCWD-resistant and susceptible lines of rainbow trout: a shift towards more EBF-expressing progenitors and fewer mature B cells in resistant animals.

PubMed

Zwollo, Patty; Ray, Jocelyn C; Sestito, Michael; Kiernan, Elizabeth; Wiens, Gregory D; Kaattari, Steve; StJacques, Brittany; Epp, Lidia

2015-01-01

Bacterial cold water disease (BCWD) is a chronic disease of rainbow trout, and is caused by the Gram-negative bacterium Flavobacterium psychrophilum (Fp), a common aquaculture pathogen. The National Center for Cool and Cold Water Aquaculture has bred two genetic lines of rainbow trout: a line of Fp-resistant trout (ARS-Fp-R or R-line trout) and a line of susceptible trout (ARS-Fp-S, or S-line). Little is known about how phenotypic selection alters immune response parameters or how such changes relate to genetic disease resistance. Herein, we quantify interindividual variation in the distribution and abundance of B cell populations (B cell signatures) and examine differences between genetic lines of naive animals. There are limited trout-specific cell surface markers currently available to resolve B cell subpopulations and thus we developed an alternative approach based on detection of differentially expressed transcription factors and intracellular cytokines. B cell signatures were compared between R-line and S-line trout by flow cytometry using antibodies against transcription factors early B cell factor-1 (EBF1) and paired domain box protein Pax5, the pro-inflammatory cytokine IL-1β, and the immunoglobulin heavy chain mu. R-line trout had higher percentages of EBF(+) B myeloid/ progenitor and pre-B cells in PBL, anterior and posterior kidney tissues compared to S-line trout. The opposite pattern was detected in more mature B cell populations: R-line trout had lower percentages of both IgM(+) mature B cells and IgM-secreting cells in anterior kidney and PBL compared to S-line trout. In vitro LPS-activation studies of PBL and spleen cell cultures revealed no significant induction differences between R-line and S-line trout. Together, our findings suggest that selective resistance to BCWD may be associated with shifts in naive animal developmental lineage commitment that result in decreased B lymphopoiesis and increased myelopoiesis in BCWD resistant trout relative to susceptible trout. Copyright © 2014 Elsevier Ltd. All rights reserved.

Landslide susceptibility assessment in Lianhua County (China): A comparison between a random forest data mining technique and bivariate and multivariate statistical models

NASA Astrophysics Data System (ADS)

Hong, Haoyuan; Pourghasemi, Hamid Reza; Pourtaghi, Zohre Sadat

2016-04-01

Landslides are an important natural hazard that causes a great amount of damage around the world every year, especially during the rainy season. The Lianhua area is located in the middle of China's southern mountainous area, west of Jiangxi Province, and is known to be an area prone to landslides. The aim of this study was to evaluate and compare landslide susceptibility maps produced using the random forest (RF) data mining technique with those produced by bivariate (evidential belief function and frequency ratio) and multivariate (logistic regression) statistical models for Lianhua County, China. First, a landslide inventory map was prepared using aerial photograph interpretation, satellite images, and extensive field surveys. In total, 163 landslide events were recognized in the study area, with 114 landslides (70%) used for training and 49 landslides (30%) used for validation. Next, the landslide conditioning factors-including the slope angle, altitude, slope aspect, topographic wetness index (TWI), slope-length (LS), plan curvature, profile curvature, distance to rivers, distance to faults, distance to roads, annual precipitation, land use, normalized difference vegetation index (NDVI), and lithology-were derived from the spatial database. Finally, the landslide susceptibility maps of Lianhua County were generated in ArcGIS 10.1 based on the random forest (RF), evidential belief function (EBF), frequency ratio (FR), and logistic regression (LR) approaches and were validated using a receiver operating characteristic (ROC) curve. The ROC plot assessment results showed that for landslide susceptibility maps produced using the EBF, FR, LR, and RF models, the area under the curve (AUC) values were 0.8122, 0.8134, 0.7751, and 0.7172, respectively. Therefore, we can conclude that all four models have an AUC of more than 0.70 and can be used in landslide susceptibility mapping in the study area; meanwhile, the EBF and FR models had the best performance for Lianhua County, China. Thus, the resultant susceptibility maps will be useful for land use planning and hazard mitigation aims.

Fabrication of tunable diffraction grating by imprint lithography with photoresist mold

NASA Astrophysics Data System (ADS)

Yamada, Itsunari; Ikeda, Yusuke; Higuchi, Tetsuya

2018-05-01

We fabricated a deformable transmission silicone [poly(dimethylsiloxane)] grating using a two-beam interference method and imprint lithography and evaluated its optical characteristics during a compression process. The grating pattern with 0.43 μm depth and 1.0 μm pitch was created on a silicone surface by an imprinting process with a photoresist mold to realize a simple, low-cost fabrication process. The first-order diffraction transmittance of this grating reached 10.3% at 632.8 nm wavelength. We also measured the relationship between the grating period and compressive stress to the fabricated elements. The grating period changed from 1.0 μm to 0.84 μm by 16.6% compression of the fabricated element in one direction, perpendicular to the grooves, and the first-order diffraction transmittance was 8.6%.

Nanosized-Particle Dispersion-Strengthened Al Matrix Composites Fabricated by the Double Mechanical Alloying Process.

PubMed

Kim, Chungseok

2018-03-01

The objective of this study was to fabricate an Al metal matrix composite strengthened by nanosized Al3Ti particles via double mechanical alloying process. Several Al-xTi alloys were fabricated, including Al-12%Ti, Al-15%Ti, and Al-12%Ti-1%Y2O3. The lattice parameter of as-milled state was calculated to be 4.0485 Å; after a milling time of 540 min, it was 4.0401 Å. This decrease was induced by Ti solutionizing into the Al matrix. The equivalent size of a coarse Al3Ti particle was 200-500 nm after the heat treatment; however, the particles were uniformly distributed and were refined through the MA2 process. The particle size of a Al3Ti phase was 30 nm or less, and the particles were uniformly distributed. These particles remained in a fine state in the matrix without growth and coarsening, even after the hot extrusion process. The microstructure of hot extruded alloys consisted of a uniform distribution of Al3Ti particles and other dispersoids in the Al matrix.

A three-dimensional optical photonic crystal with designed point defects

NASA Astrophysics Data System (ADS)

Qi, Minghao; Lidorikis, Elefterios; Rakich, Peter T.; Johnson, Steven G.; Joannopoulos, J. D.; Ippen, Erich P.; Smith, Henry I.

2004-06-01

Photonic crystals offer unprecedented opportunities for miniaturization and integration of optical devices. They also exhibit a variety of new physical phenomena, including suppression or enhancement of spontaneous emission, low-threshold lasing, and quantum information processing. Various techniques for the fabrication of three-dimensional (3D) photonic crystals-such as silicon micromachining, wafer fusion bonding, holographic lithography, self-assembly, angled-etching, micromanipulation, glancing-angle deposition and auto-cloning-have been proposed and demonstrated with different levels of success. However, a critical step towards the fabrication of functional 3D devices, that is, the incorporation of microcavities or waveguides in a controllable way, has not been achieved at optical wavelengths. Here we present the fabrication of 3D photonic crystals that are particularly suited for optical device integration using a lithographic layer-by-layer approach. Point-defect microcavities are introduced during the fabrication process and optical measurements show they have resonant signatures around telecommunications wavelengths (1.3-1.5µm). Measurements of reflectance and transmittance at near-infrared are in good agreement with numerical simulations.

Study of Automated Module Fabrication for Lightweight Solar Blanket Utilization

NASA Technical Reports Server (NTRS)

Gibson, C. E.

1979-01-01

Cost-effective automated techniques for accomplishing the titled purpose; based on existing in-house capability are described. As a measure of the considered automation, the production of a 50 kilowatt solar array blanket, exclusive of support and deployment structure, within an eight-month fabrication period was used. Solar cells considered for this blanket were 2 x 4 x .02 cm wrap-around cells, 2 x 2 x .005 cm and 3 x 3 x .005 cm standard bar contact thin cells, all welded contacts. Existing fabrication processes are described, the rationale for each process is discussed, and the capability for further automation is discussed.

Application of a GIS-/remote sensing-based approach for predicting groundwater potential zones using a multi-criteria data mining methodology.

PubMed

Mogaji, Kehinde Anthony; Lim, Hwee San

2017-07-01

This study integrates the application of Dempster-Shafer-driven evidential belief function (DS-EBF) methodology with remote sensing and geographic information system techniques to analyze surface and subsurface data sets for the spatial prediction of groundwater potential in Perak Province, Malaysia. The study used additional data obtained from the records of the groundwater yield rate of approximately 28 bore well locations. The processed surface and subsurface data produced sets of groundwater potential conditioning factors (GPCFs) from which multiple surface hydrologic and subsurface hydrogeologic parameter thematic maps were generated. The bore well location inventories were partitioned randomly into a ratio of 70% (19 wells) for model training to 30% (9 wells) for model testing. Application results of the DS-EBF relationship model algorithms of the surface- and subsurface-based GPCF thematic maps and the bore well locations produced two groundwater potential prediction (GPP) maps based on surface hydrologic and subsurface hydrogeologic characteristics which established that more than 60% of the study area falling within the moderate-high groundwater potential zones and less than 35% falling within the low potential zones. The estimated uncertainty values within the range of 0 to 17% for the predicted potential zones were quantified using the uncertainty algorithm of the model. The validation results of the GPP maps using relative operating characteristic curve method yielded 80 and 68% success rates and 89 and 53% prediction rates for the subsurface hydrogeologic factor (SUHF)- and surface hydrologic factor (SHF)-based GPP maps, respectively. The study results revealed that the SUHF-based GPP map accurately delineated groundwater potential zones better than the SHF-based GPP map. However, significant information on the low degree of uncertainty of the predicted potential zones established the suitability of the two GPP maps for future development of groundwater resources in the area. The overall results proved the efficacy of the data mining model and the geospatial technology in groundwater potential mapping.

Al transmon qubits on silicon-on-insulator for quantum device integration

NASA Astrophysics Data System (ADS)

Keller, Andrew J.; Dieterle, Paul B.; Fang, Michael; Berger, Brett; Fink, Johannes M.; Painter, Oskar

2017-07-01

We present the fabrication and characterization of an aluminum transmon qubit on a silicon-on-insulator substrate. Key to the qubit fabrication is the use of an anhydrous hydrofluoric vapor process which selectively removes the lossy silicon oxide buried underneath the silicon device layer. For a 5.6 GHz qubit measured dispersively by a 7.1 GHz resonator, we find T1 = 3.5 μs and T2* = 2.2 μs. This process in principle permits the co-fabrication of silicon photonic and mechanical elements, providing a route towards chip-scale integration of electro-opto-mechanical transducers for quantum networking of superconducting microwave quantum circuits. The additional processing steps are compatible with established fabrication techniques for aluminum transmon qubits on silicon.

Overcoming Short-Circuit in Lead-Free CH3NH3SnI3 Perovskite Solar Cells via Kinetically Controlled Gas-Solid Reaction Film Fabrication Process.

PubMed

Yokoyama, Takamichi; Cao, Duyen H; Stoumpos, Constantinos C; Song, Tze-Bin; Sato, Yoshiharu; Aramaki, Shinji; Kanatzidis, Mercouri G

2016-03-03

The development of Sn-based perovskite solar cells has been challenging because devices often show short-circuit behavior due to poor morphologies and undesired electrical properties of the thin films. A low-temperature vapor-assisted solution process (LT-VASP) has been employed as a novel kinetically controlled gas-solid reaction film fabrication method to prepare lead-free CH3NH3SnI3 thin films. We show that the solid SnI2 substrate temperature is the key parameter in achieving perovskite films with high surface coverage and excellent uniformity. The resulting high-quality CH3NH3SnI3 films allow the successful fabrication of solar cells with drastically improved reproducibility, reaching an efficiency of 1.86%. Furthermore, our Kelvin probe studies show the VASP films have a doping level lower than that of films prepared from the conventional one-step method, effectively lowering the film conductivity. Above all, with (LT)-VASP, the short-circuit behavior often obtained from the conventional one-step-fabricated Sn-based perovskite devices has been overcome. This study facilitates the path to more successful Sn-perovskite photovoltaic research.

Breastfeeding and Complementary Feeding Practices among HIV-Exposed Infants in Coastal Tanzania.

PubMed

Williams, Anne M; Chantry, Caroline; Geubbels, Eveline L; Ramaiya, Astha K; Shemdoe, Aloisia I; Tancredi, Daniel J; Young, Sera L

2016-02-01

Appropriate infant feeding is a persistent challenge for human immunodeficiency virus (HIV)-infected mothers in sub-Saharan Africa. This study aimed to describe correlates of infant feeding among HIV-infected mothers in coastal Tanzania. HIV-infected women (n = 400) with infants younger than 18 months were enrolled from June to November 2011 from 3 public health facilities in Pwani, Tanzania: Tumbi Regional Hospital (TRH), Chalinze Health Center (CHC), and Bagamoyo District Hospital (BDH). Participants were surveyed about sociodemographics and infant feeding behavior at enrollment; infant feeding data were collected prospectively and retrospectively in the month of study follow-up. Statistically significant correlates of exclusive breastfeeding (EBF) were infant age (months) (adjusted odds ratio [AOR] = 0.6; 95% confidence interval [CI], 0.5-0.9), enrollment facility (TRH: reference; CHC: AOR = 5.0, 95% CI, 1.2-20.8; BDH: AOR = 11.6, 95% CI, 2.3-59.9), and HIV disclosure to one's mother (AOR = 0.2; 95% CI, 0.1-0.6). Exclusive breastfeeding prevalence among infants younger than 6 months was 77%, but 50% of infants older than 6 months no longer receiving breast milk did not receive animal source foods (ASF) daily. Enrollment facility (TRH: reference; CHC: AOR = 0.2, 95% CI, 0.1-1.0; BDH: AOR = 0.1, 95% CI, 0.01-0.4) and HIV disclosure (to mother-in-law: AOR = 0.2, 95% CI, 0.1-0.8; to brother: AOR = 0.3, 95% CI, 0.1-0.8) were negatively associated with ASF provision. High prevalence of EBF suggests that it is an attainable behavior, whereas low prevalence of daily ASF provision suggests that adequate diets are difficult to achieve after breastfeeding cessation. These findings support current recommendations for HIV-infected mothers in resource-poor regions to continue breastfeeding for at least 1 year and suggest the need for greater support with complementary feeding. Associations between HIV disclosure and infant feeding merit further exploration, and correlations between enrollment facility and infant feeding highlight the potential influence of clinics on achieving infant feeding recommendations. © The Author(s) 2015.

Microsacle PolySilicon Hemispherical Shell Resonating Gyroscopes with Integrated Three-dimensional Curved Electrodes

NASA Astrophysics Data System (ADS)

Zhuang, Xuye; Chen, Binggen; Wang, Xinlong; Yu, Lei; Wang, Fan; Guo, Shuwen

2018-03-01

A novel approach for fabrication of polysilicon hemispherical resonator gyroscopes with integrated 3-D curved electrodes is developed and experimentally demonstrated. The 3-D polysilicon electrodes are integrated as a part of the hemispherical shell resonator’s fabrication process, and no extra assembly process are needed, ensuring the symmetry of the shell resonator. The fabrication process and materials used are compatible with the traditional semiconductor process, indicating the gyroscope has a high potential for mass production and commercial development. Without any trimming or tuning of the n=2 wineglass frequencies, a 28 kHz shell resonator demonstrates a 0.009% frequency mismatch between two degenerate wineglass modes, and a 13.6 kHz resonator shows a frequency split of 0.03%. The ring-down time of a fabricated resonator is 0.51 s, corresponding to a Q of 22000, at 0.01 Pa vacuum and room temperature. The prototype of the gyroscope is experimentally analyzed, and the scale factor of the gyro is 1.15 mV/°/s, the bias instability is 80 °/h.

Analysis of current driving capability of pentacene TFTs for OLEDs

NASA Astrophysics Data System (ADS)

Ryu, Gi Seong; Byun, Hyun Sook; Xu, Yong Xian; Pyo, Kyung Soo; Choe, Ki Beom; Song, Chung Kun

2005-01-01

The flexible display and the application of Roll-To-Roll process is difficult because high temperature process of a-Si;H TFT and poly-Si TFT limited the use of plastic substrate. We proposed AMOLED using Pentacene TFT (OTFT) to fabricate flexible display. The first stage for OTFT application to OLED, we analyzed OTFT as driving device of OLED. The process performed on glass and plastic (PET) substrate that is coated ITO and PVP is used for gate insulator. The field effect mobility of the fabricated OTFT is 0.1~0.3cm2/V"sec and Ion/Ioff current ratio is 103~105. OLED is fabricated with two stories structure of TPD and Alq3, and we can observe the light at 5V by the naked eye. The wavelength of observed lights is 530nm ~550nm. We can confirm the driving of OLED due to OTFT using Test panel and observe OLED control by gate voltage of OTFT. Also, we verify designed structure and process, and make a demonstration fabricating 64 by 64 backplane based on Test panel.

Fabrication of PDMS through-holes using the MIMIC method and the surface treatment by atmospheric-pressure CH4/He RF plasma

NASA Astrophysics Data System (ADS)

Choi, Jongchan; Lee, Kyeong-Hwan; Yang, Sung

2011-09-01

This note presents a simple fabrication process for patterning micro through-holes in a PDMS layer by a combination of the micromolding in capillaries (MIMIC) method and the surface treatment by atmospheric-pressure CH4/He RF plasma. The fabrication process is confirmed by forming micro through-holes with various shapes including circle, C-shape, open microfluidic channel and hemisphere. All micro through-holes of various shapes in a wide range of diameters and heights are well fabricated by the proposed method. Also, a 3D micromixer containing a PDMS micro through-hole layer formed by the proposed method is built and its performance is tested as another practical demonstration of the proposed fabrication method. Therefore, we believe that the proposed fabrication process will build a PDMS micro through-hole layer in a simple and easy way and will contribute to developing highly efficient multi-layered microfluidic systems, which may require PDMS micro through-hole layers.

Processing and Characterization of Peti Composites Fabricated by High Temperature Vartm (Section)

NASA Technical Reports Server (NTRS)

Ghose, Sayata; Cano, Roberto J.; Watson, Kent A.; Britton, Sean M.; Jensen, Brian J.; Connell, John W.; Smith, Joseph G., Jr.; Loos, Alfred C.; Heider, Dirk

2011-01-01

The use of composites as primary structures on aerospace vehicles has increased dramatically over the past decade, but so have the production costs associated with their fabrication. For certain composites, high temperature vacuum assisted resin transfer molding (HT-VARTM) can offer reduced fabrication costs compared to conventional autoclave techniques. The process has been successfully used with phenylethynyl terminated imide (PETI) resins developed by NASA Langley Research Center (LaRC). In the current study, three PETI resins have been used to make test specimens using HT-VARTM. Based on previous work at NASA LaRC, larger panels with a quasi-isotropic lay-up were fabricated. The resultant composite specimens exhibited void contents of 3% by volume depending on the type of carbon fabric preform used. Mechanical properties of the panels were determined at both room and elevated temperatures. Fabric permeability characterizations and limited process modeling efforts were carried out to determine infusion times and composite panel size limitations. In addition, new PETI based resins were synthesized specifically for HT-VARTM.

Optimised process for fabricating tapered long period gratings

NASA Astrophysics Data System (ADS)

Mullaney, K.; Staines, S. E.; James, S. W.; Tatam, R. P.

2017-04-01

The process of fabricating tapered long period gratings (TLPGs) using a CO2 laser is described. TLPGs with a period spacing of 378 μm, were fabricated by optimization of the taper waist diameter and careful control of the duty-cycle and its uniformity along the length of the grating. The 6-period TLPGs exhibited a pass-band insertion loss of 0.6 dB, resonance band extinction values of 3 dB and had a physical length of 2.27 mm.

Aerosol based direct-write micro-additive fabrication method for sub-mm 3D metal-dielectric structures

NASA Astrophysics Data System (ADS)

Rahman, Taibur; Renaud, Luke; Heo, Deuk; Renn, Michael; Panat, Rahul

2015-10-01

The fabrication of 3D metal-dielectric structures at sub-mm length scale is highly important in order to realize low-loss passives and GHz wavelength antennas with applications in wearable and Internet-of-Things (IoT) devices. The inherent 2D nature of lithographic processes severely limits the available manufacturing routes to fabricate 3D structures. Further, the lithographic processes are subtractive and require the use of environmentally harmful chemicals. In this letter, we demonstrate an additive manufacturing method to fabricate 3D metal-dielectric structures at sub-mm length scale. A UV curable dielectric is dispensed from an Aerosol Jet system at 10-100 µm length scale and instantaneously cured to build complex 3D shapes at a length scale  <1 mm. A metal nanoparticle ink is then dispensed over the 3D dielectric using a combination of jetting action and tilted dispense head, also using the Aerosol Jet technique and at a length scale 10-100 µm, followed by the nanoparticle sintering. Simulation studies are carried out to demonstrate the feasibility of using such structures as mm-wave antennas. The manufacturing method described in this letter opens up the possibility of fabricating an entirely new class of custom-shaped 3D structures at a sub-mm length scale with potential applications in 3D antennas and passives.

New prospects in pretreatment of cotton fabrics using microwave heating.

PubMed

Hashem, M; Taleb, M Abou; El-Shall, F N; Haggag, K

2014-03-15

As microwaves are known to give fast and rapid volume heating, the present study is undertaken to investigate the use of microwave heating for pretreatment cotton fabrics to reduce the pretreatment time, chemicals and water. The onset of the microwave heating technique on the physicochemical and performance properties of desized, scoured and bleached cotton fabric is elucidated and compared with those obtained on using conventional thermal heating. Combined one-step process for desizing, scouring and bleaching of cotton fabric under microwave heating was also investigated. The dual effect of adding urea, (as microwave absorber and hydrogen peroxide activator) has been exploiting to accelerate the pretreatment reaction of cotton fabric. DSC, FT-IR and SEM have been used to investigate the onset of microwave on the morphological and chemical change of cotton cellulose after pretreatment and bleaching under microwave heating. Results obtained show that, a complete fabric preparation was obtained in just 5 min on using microwave in pretreatments process and the fabric properties were comparable to those obtained in traditional pretreatment process which requires 2.5-3h for completion. Copyright © 2013 Elsevier Ltd. All rights reserved.

Femtosecond Laser Fabrication of Monolithically Integrated Microfluidic Sensors in Glass

PubMed Central

He, Fei; Liao, Yang; Lin, Jintian; Song, Jiangxin; Qiao, Lingling; Cheng, Ya; Sugioka, Koji

2014-01-01

Femtosecond lasers have revolutionized the processing of materials, since their ultrashort pulse width and extremely high peak intensity allows high-quality micro- and nanofabrication of three-dimensional (3D) structures. This unique capability opens up a new route for fabrication of microfluidic sensors for biochemical applications. The present paper presents a comprehensive review of recent advancements in femtosecond laser processing of glass for a variety of microfluidic sensor applications. These include 3D integration of micro-/nanofluidic, optofluidic, electrofluidic, surface-enhanced Raman-scattering devices, in addition to fabrication of devices for microfluidic bioassays and lab-on-fiber sensors. This paper describes the unique characteristics of femtosecond laser processing and the basic concepts involved in femtosecond laser direct writing. Advanced spatiotemporal beam shaping methods are also discussed. Typical examples of microfluidic sensors fabricated using femtosecond lasers are then highlighted, and their applications in chemical and biological sensing are described. Finally, a summary of the technology is given and the outlook for further developments in this field is considered. PMID:25330047

Solution processed flexible organic thin film back-gated transistors based on polyimide dielectric films

NASA Astrophysics Data System (ADS)

Park, Janghoon; Min, Yoonki; Lee, Dongjin

2018-04-01

An organic thin film back-gated transistor (OBGT) was fabricated and characterized. The gate electrode was printed on the back side of substrate, and the dielectric layer was omitted by substituting the dielectric layer with the polyimide (PI) film substrate. Roll-to-roll (R2R) gravure printing, doctor blading, and drop casting methods were used to fabricate the OBGT. The printed OBGT device shows better performance compared with an OTFT device based on dielectric layer of BaTiO3. Additionally, a calendering process enhanced the performance by a factor of 3 to 7 (mobility: 0.016 cm2/V.s, on/off ratio: 9.17×103). A bending test was conducted to confirm the flexibility and durability of the OBGT device. The results show the fabricated device endures 20000-cyclic motions. The realized OBGT device was successfully fabricated and working, which is meaningful for production engineering from the viewpoint of process development.

Wide-bandgap III-Nitride based Second Harmonic Generation

DTIC Science & Technology

2014-10-02

fabrication process for a GaN LPS. Fig. 1: 3-step Fabrication process of a GaN based lateral polar structure. ( a ) Growth of a 20 nm AlN buffer layer...etching of the LT-AlN stripes. This results are shown in Fig. 2 ( a ) and (b). Fig. 2: AFM images of KOH ( a ) and RIE (b) patterned templates for lateral ...was varied between 0.6 - 1.0. FIG. 3: Growth process of AlGaN based Lateral Polar Structures. ( a ) RIE patterning. (b) Growth of HT- AlN. (c

Patient-Specific Surgical Implants Made of 3D Printed PEEK: Material, Technology, and Scope of Surgical Application

PubMed Central

Okolo, Brando; Popp, Uwe

2018-01-01

Additive manufacturing (AM) is rapidly gaining acceptance in the healthcare sector. Three-dimensional (3D) virtual surgical planning, fabrication of anatomical models, and patient-specific implants (PSI) are well-established processes in the surgical fields. Polyetheretherketone (PEEK) has been used, mainly in the reconstructive surgeries as a reliable alternative to other alloplastic materials for the fabrication of PSI. Recently, it has become possible to fabricate PEEK PSI with Fused Filament Fabrication (FFF) technology. 3D printing of PEEK using FFF allows construction of almost any complex design geometry, which cannot be manufactured using other technologies. In this study, we fabricated various PEEK PSI by FFF 3D printer in an effort to check the feasibility of manufacturing PEEK with 3D printing. Based on these preliminary results, PEEK can be successfully used as an appropriate biomaterial to reconstruct the surgical defects in a “biomimetic” design. PMID:29713642

Patient-Specific Surgical Implants Made of 3D Printed PEEK: Material, Technology, and Scope of Surgical Application.

PubMed

Honigmann, Philipp; Sharma, Neha; Okolo, Brando; Popp, Uwe; Msallem, Bilal; Thieringer, Florian M

2018-01-01

Additive manufacturing (AM) is rapidly gaining acceptance in the healthcare sector. Three-dimensional (3D) virtual surgical planning, fabrication of anatomical models, and patient-specific implants (PSI) are well-established processes in the surgical fields. Polyetheretherketone (PEEK) has been used, mainly in the reconstructive surgeries as a reliable alternative to other alloplastic materials for the fabrication of PSI. Recently, it has become possible to fabricate PEEK PSI with Fused Filament Fabrication (FFF) technology. 3D printing of PEEK using FFF allows construction of almost any complex design geometry, which cannot be manufactured using other technologies. In this study, we fabricated various PEEK PSI by FFF 3D printer in an effort to check the feasibility of manufacturing PEEK with 3D printing. Based on these preliminary results, PEEK can be successfully used as an appropriate biomaterial to reconstruct the surgical defects in a "biomimetic" design.

3D printed microfluidics for biological applications.

PubMed

Ho, Chee Meng Benjamin; Ng, Sum Huan; Li, King Ho Holden; Yoon, Yong-Jin

2015-01-01

The term "Lab-on-a-Chip," is synonymous with describing microfluidic devices with biomedical applications. Even though microfluidics have been developing rapidly over the past decade, the uptake rate in biological research has been slow. This could be due to the tedious process of fabricating a chip and the absence of a "killer application" that would outperform existing traditional methods. In recent years, three dimensional (3D) printing has been drawing much interest from the research community. It has the ability to make complex structures with high resolution. Moreover, the fast building time and ease of learning has simplified the fabrication process of microfluidic devices to a single step. This could possibly aid the field of microfluidics in finding its "killer application" that will lead to its acceptance by researchers, especially in the biomedical field. In this paper, a review is carried out of how 3D printing helps to improve the fabrication of microfluidic devices, the 3D printing technologies currently used for fabrication and the future of 3D printing in the field of microfluidics.

Nano-Al{sub 2}O{sub 3} multilayer film deposition on cotton fabrics by layer-by-layer deposition method

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ugur, Sule S., E-mail: sule@mmf.sdu.edu.tr; Sariisik, Merih; Aktas, A. Hakan

Highlights: {yields} Cationic charges were created on the cotton fibre surfaces with 2,3-epoxypropyltrimethylammonium chloride. {yields} Al{sub 2}O{sub 3} nanoparticles were deposited on the cotton fabrics by layer-by-layer deposition. {yields} The fabrics deposited with the Al{sub 2}O{sub 3} nanoparticles exhibit better UV-protection and significant flame retardancy properties. {yields} The mechanical properties were improved after surface film deposition. -- Abstract: Al{sub 2}O{sub 3} nanoparticles were used for fabrication of multilayer nanocomposite film deposition on cationic cotton fabrics by electrostatic self-assembly to improve the mechanical, UV-protection and flame retardancy properties of cotton fabrics. Cotton fabric surface was modified with a chemical reaction tomore » build-up cationic charge known as cationization. Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy, X-ray Photoelectron Spectroscopy and Scanning Electron Microscopy were used to verify the presence of deposited nanolayers. Air permeability, whiteness value, tensile strength, UV-transmittance and Limited Oxygen Index properties of cotton fabrics were analyzed before and after the treatment of Al{sub 2}O{sub 3} nanoparticles by electrostatic self-assemblies. It was proved that the flame retardancy, tensile strength and UV-transmittance of cotton fabrics can be improved by Al{sub 2}O{sub 3} nanoparticle additive through electrostatic self-assembly process.« less

Effect of post-annealing on sputtered MoS2 films

NASA Astrophysics Data System (ADS)

Wong, W. C.; Ng, S. M.; Wong, H. F.; Cheng, W. F.; Mak, C. L.; Leung, C. W.

2017-12-01

Typical routes for fabricating MoS2-based electronic devices rely on the transfer of as-prepared flakes to target substrates, which is incompatible with conventional device fabrication methods. In this work we investigated the preparation of MoS2 films by magnetron sputtering. By subjecting room-temperature sputtered MoS2 films to post-annealing at mild conditions (450 °C in a nitrogen flow), crystalline MoS2 films were formed. To demonstrate the compatibility of the technique with typical device fabrication processes, MoS2 was prepared on epitaxial magnetic oxide films of La0.7Sr0.3MnO3, and the magnetic behavior of the films were unaffected by the post-annealing process. This work demonstrates the possibility of fabricating electronic and spintronic devices based on continuous MoS2 films prepared by sputtering deposition.

TU-H-BRC-01: A New Fabrication Method for Secondary Skin Collimation Using 3D Scanner and 3D Printer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jung, J; Potter, N; Suh, T

Purpose: Using secondary skin collimation (SSC) to protect the critical organ surrounding the tumors is always desirable for electron and/or ortho-voltage treatments. However, the time-consuming and labor-intensive fabrication processes of current method (manually fabricate the lead mask) restrict the general use of SSC. The aim of this study is to develop a new SSC fabrication method using 3D scanning and 3D printing technologies in order to largely decrease the human labor involvement and fabrication time, also improve the fabrication accuracy. Methods: First, the patient surface was scanned with a 3D scanner (Structure Sensor, Occipital, CO). The raw scan data wasmore » subsequently transferred to a 3D modeling software (Rhinoceros, Ver. 5.0, McNeel North America, Seattle, WA). The tumor contour was then digitized and shielding region was determined by clinicians in the same software. The corresponding SCC conformed to the skin surface was then automatically generated by the software with the proper shielding thickness. The shell of the SCC (with hollow inside) was consequently printed by a 3D printer (Lulzbot TAZ, Aleph Objects, CO) using plastic material. Finally, the hollow mold of SCC was filled up with a melted cerrobend alloy. Once the cerrobend alloy cooled down, the fabrication of SCC was accomplished. Results: The results indicated the proposed method can achieve a much shorter time on making a SCC compared with tradition fabrication method. The processes of making a skin contour model for patients have been eliminated with the new method. SCC created by the new method possessed better accuracy and better conformality to patient’s skin contours. Conclusion: In this study, we have demonstrated a new method for the SCC fabrication. It is anticipated that our method can be an alternative way to replace conventional manual-based methods for electron and/or ortho-voltage SCC fabrication. This research was supported by the Global Ph.D. Fellowship Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (Grant No. 2015H1A2A1034071), Republic of Korea.« less

Doped Aluminum Gallium Arsenide (AlGaAs)/Gallium Arsenide (GaAs) Photoconductive Semiconductor Switch (PCSS) Fabrication

DTIC Science & Technology

2016-09-27

contact regions and epitaxial capping layer are fabricated to investigate the advantages of both approaches. Devices were fabricated with various... Contacts 7 2.5 Packaging 11 3. Conclusions 12 4. References 13 Appendix. Detailed Fabrication Process 15 List of Symbols, Abbreviations, and...regions in violet (overlaying previous patterns) .......7 Fig. 6 Mask 4: intrinsic device contact window regions in orange (overlaying previous

The Layer of Kevlar Angle-interlock Woven Fabric Effect on the Tensile Properties of Composite Materials

NASA Astrophysics Data System (ADS)

Xie, Wan-Chen; Guo, Xu-Yi; Yan, Tao; Zhang, Shang-Yong

2017-09-01

This article is based on the structure of three-dimensional angle-interlock longitudinal.The 3-layer, 5-layer, 7-layer and 9-layer of angle-interlock 3D fabrics are woven on sample weaving machine respectively with the 1500D Kevlar fiber twist filament produced by United States DuPont. At the same time, Kevlar plain weave fabric is woven, and three, five, seven and nine layers’ fabric are to be compared. In the process of VARTM composite technology, epoxy resin is matrix material, acetone is diluent, triethylene tetramine is curing agent and the five different fabrics are the reinforced materials respectively. Finally, eight different three-dimensional woven fabric composites were prepared. In this paper, the tensile properties of eight kinds of three-dimensional woven fabric composites were tested respectively.Finally, it is concluded that the five-layer angle-interlock woven fabric prepared by Kevlar fiber shows the best tensile property.

A top-down approach for fabricating three-dimensional closed hollow nanostructures with permeable thin metal walls.

PubMed

Barrios, Carlos Angulo; Canalejas-Tejero, Víctor

2017-01-01

We report on a top-down method for the controlled fabrication of three-dimensional (3D), closed, thin-shelled, hollow nanostructures (nanocages) on planar supports. The presented approach is based on conventional microelectronic fabrication processes and exploits the permeability of thin metal films to hollow-out polymer-filled metal nanocages through an oxygen-plasma process. The technique is used for fabricating arrays of cylindrical nanocages made of thin Al shells on silicon substrates. This hollow metal configuration features optical resonance as revealed by spectral reflectance measurements and numerical simulations. The fabricated nanocages were demonstrated as a refractometric sensor with a measured bulk sensitivity of 327 nm/refractive index unit (RIU). The pattern design flexibility and controllability offered by top-down nanofabrication techniques opens the door to the possibility of massive integration of these hollow 3D nano-objects on a chip for applications such as nanocontainers, nanoreactors, nanofluidics, nano-biosensors and photonic devices.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bolat, S., E-mail: bolat@ee.bilkent.edu.tr, E-mail: aokyay@ee.bilkent.edu.tr; Tekcan, B.; UNAM, National Nanotechnology Research Center, Bilkent University, Ankara 06800

We report GaN thin film transistors (TFT) with a thermal budget below 250 °C. GaN thin films are grown at 200 °C by hollow cathode plasma-assisted atomic layer deposition (HCPA-ALD). HCPA-ALD-based GaN thin films are found to have a polycrystalline wurtzite structure with an average crystallite size of 9.3 nm. TFTs with bottom gate configuration are fabricated with HCPA-ALD grown GaN channel layers. Fabricated TFTs exhibit n-type field effect characteristics. N-channel GaN TFTs demonstrated on-to-off ratios (I{sub ON}/I{sub OFF}) of 10{sup 3} and sub-threshold swing of 3.3 V/decade. The entire TFT device fabrication process temperature is below 250 °C, which is the lowest process temperaturemore » reported for GaN based transistors, so far.« less

Connecting [NiFe]- and [FeFe]-Hydrogenases: Mixed-Valence Nickel-Iron Dithiolates With Rotated Structures

PubMed Central

Schilter, David; Rauchfuss, Thomas B.; Stein, Matthias

2012-01-01

A series of mixed-valence iron-nickel dithiolates is described that exhibits structures similar to those of mixed-valence diiron dithiolates. Interaction of tricarbonyl salt [(dppe)Ni(pdt)Fe(CO)3]BF4 ([1]BF4, dppe = Ph2PCH2CH2PPh2, pdtH2 = HSCH2CH2CH2SH) with P-donor ligands (L) afforded the substituted derivatives [(dppe)Ni(pdt)Fe(CO)2L]BF4 incorporating L = PHCy2 ([1a]BF4), PPh(NEt2)2 ([1b]BF4), P(NMe2)3 ([1c]BF4), P(i-Pr)3 ([1d]BF4) and PCy3 ([1e]BF4). The related precursor [(dcpe)Ni(pdt)Fe(CO)3]BF4 ([2]BF4, dcpe = Cy2PCH2CH2PCy2) gave the more electron-rich family of compounds [(dcpe)Ni(pdt)Fe(CO)2L]BF4 for L = PPh2(2-pyridyl) ([2a]BF4), PPh3 ([2b]BF4) and PCy3 ([2c]BF4). For bulky and strongly basic monophosphorus ligands, the salts feature distorted Fe coordination geometries: crystallographic analyses of [1e]BF4 and [2c]BF4 showed they adopt ‘rotated’ Fe(I) centers, in which PCy3 occupies a basal site and one CO ligand partially bridges the Ni and Fe centers. Like the undistorted mixed-valence derivatives, the new class of complexes are described as Ni(II)Fe(I) (S = ½) systems according to EPR spectroscopy, although with attenuated 31P hyperfine interactions. DFT calculations using the BP86, B3LYP, and PBE0 exchange-correlation functionals agree with the structural and spectroscopic data, suggesting that the spin for [1e]+ is localized in a Fe(I)-centered d(z2) orbital, orthogonal to the Fe-P bond. The PCy3 complexes, rare examples of species featuring ‘rotated’ Fe centers, both structurally and spectroscopically resemble mixed-valence diiron dithiolates. Also reproducing the NiS2Fe core of the [NiFe]-H2ase active site, the hybrid models incorporate key features of the two major classes of H2ase. Furthermore, cyclic voltammetry experiments suggest that the highly basic phosphine ligands enable a second oxidation corresponding to the couple [(dxpe)Ni(pdt)Fe(CO)2L]+/2+. The resulting unsaturated 32e− dications represent the closest approach to modeling the highly electrophilic Ni-SIa state. In the case of L = PPh2(2-pyridyl) chelation of this ligand accompanies the second oxidation. PMID:22838645

Fabrication of cast particle-reinforced metals via pressure infiltration

NASA Technical Reports Server (NTRS)

Klier, E. M.; Mortensen, A.; Cornie, J. A.; Flemings, M. C.

1991-01-01

A new casting process for fabrication of particle-reinforced metals is presented whereby a composite of particulate reinforcing phase in metal is first produced by pressure infiltration. This composite is then diluted in additional molten metal to obtain the desired reinforcement volume fraction and metal composition. This process produces a pore-free as-cast particulate metal-matrix composite. This process is demonstrated for fabrication of magnesium-matrix composites containing SiC reinforcements of average diameter 30, 10 and 3 microns. It is compared with the compocasting process, which was investigated as well for similar SiC particles in Mg-10 wt pct Al, and resulted in unacceptable levels of porosity in the as-cast composite.

Fabrication of an interim complete removable dental prosthesis with an in-office digital light processing three-dimensional printer: A proof-of-concept technique.

PubMed

Lin, Wei-Shao; Harris, Bryan T; Pellerito, John; Morton, Dean

2018-04-30

This report describes a proof of concept for fabricating an interim complete removable dental prosthesis with a digital light processing 3-dimensional (3D) printer. Although an in-office 3D printer can reduce the overall production cost for an interim complete removable dental prosthesis, the process has not been validated with clinical studies. This report provided a preliminary proof of concept in developing a digital workflow for the in-office additively manufactured interim complete removable dental prosthesis. Copyright © 2018 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

3D Printing Multi-Functionality: Embedded RF Antennas and Components

NASA Technical Reports Server (NTRS)

Shemelya, C. M.; Zemba, M.; Liang, M.; Espalin, D.; Kief, C.; Xin, H.; Wicker, R. B.; MacDonald, E. W.

2015-01-01

Significant research and press has recently focused on the fabrication freedom of Additive Manufacturing (AM) to create both conceptual models and final end-use products. This flexibility allows design modifications to be immediately reflected in 3D printed structures, creating new paradigms within the manufacturing process. 3D printed products will inevitably be fabricated locally, with unit-level customization, optimized to unique mission requirements. However, for the technology to be universally adopted, the processes must be enhanced to incorporate additional technologies; such as electronics, actuation, and electromagnetics. Recently, a novel 3D printing platform, Multi3D manufacturing, was funded by the presidential initiative for revitalizing manufacturing in the USA using 3D printing (America Makes - also known as the National Additive Manufacturing Innovation Institute). The Multi3D system specifically targets 3D printed electronics in arbitrary form; and building upon the potential of this system, this paper describes RF antennas and components fabricated through the integration of material extrusion 3D printing with embedded wire, mesh, and RF elements.

Coplanar back contacts for thin silicon solar cells

NASA Technical Reports Server (NTRS)

Thornhill, J. W.; Sipperly, W. E.

1980-01-01

A process for fabricating 2 to 3 mil wraparound solar cells was formulated. Sample thin wraparound cells were fabricated using this process. The process used a reinforced perimeter construction to reduce the breakage that occurs during handling of the wafers. A retracting piston post was designed and fabricated to help minimize the breakage that occurs during the screen printing process. Two alternative methods of applying the aluminum back surface field were investigated. In addition to the standard screen printed back surface field, both spin-on and evaporated aluminum techniques were researched. Neither spin-on nor evaporated aluminum made any noticeable improvement over the screen printing technique. A fine screen mesh was chosen for the application of the aluminum paste back surface field. The optimum time and temperature for firing the aluminum turned out to be thirty seconds at 850 C. The development work on the dielectric included looking at three dielectrics for the wraparound application. Transene 1000, Thick Film Systems 1126RCB and an in house formulation 61-2-2A were all tested. Cells with pre-dielectric thickness of 3.0-0-3.5 mils using Transene 1000 as the wraparound dielectric and the procedure outlined above showed an average efficiency of 10.7 percent. Thinner cells were fabricated, but had an unacceptable yield and efficiency.

Optofluidic fabrication for 3D-shaped particles

NASA Astrophysics Data System (ADS)

Paulsen, Kevin S.; di Carlo, Dino; Chung, Aram J.

2015-04-01

Complex three-dimensional (3D)-shaped particles could play unique roles in biotechnology, structural mechanics and self-assembly. Current methods of fabricating 3D-shaped particles such as 3D printing, injection moulding or photolithography are limited because of low-resolution, low-throughput or complicated/expensive procedures. Here, we present a novel method called optofluidic fabrication for the generation of complex 3D-shaped polymer particles based on two coupled processes: inertial flow shaping and ultraviolet (UV) light polymerization. Pillars within fluidic platforms are used to deterministically deform photosensitive precursor fluid streams. The channels are then illuminated with patterned UV light to polymerize the photosensitive fluid, creating particles with multi-scale 3D geometries. The fundamental advantages of optofluidic fabrication include high-resolution, multi-scalability, dynamic tunability, simple operation and great potential for bulk fabrication with full automation. Through different combinations of pillar configurations, flow rates and UV light patterns, an infinite set of 3D-shaped particles is available, and a variety are demonstrated.

Space Construction Automated Fabrication Experiment Definition Study (SCAFEDS), part 3. Volume 3: Requirements

NASA Technical Reports Server (NTRS)

1979-01-01

The performance, design and verification requirements for the space Construction Automated Fabrication Experiment (SCAFE) are defined. The SCAFE program defines, develops, and demonstrates the techniques, processes, and equipment required for the automatic fabrication of structural elements in space and for the assembly of such elements into a large, lightweight structure. The program defines a large structural platform to be constructed in orbit using the space shuttle as a launch vehicle and construction base.

A sustainable and green process for scouring of cotton fabrics using xylano-pectinolytic synergism: switching from noxious chemicals to eco-friendly catalysts.

PubMed

Singh, Avtar; Kaur, Amanjot; Patra, Arun Kumar; Mahajan, Ritu

2018-04-01

The objective of this research was to develop an appropriate, eco-friendly, cost-effective bioscouring methodology for removing natural impurities from cotton fabric. Maximum bioscouring was achieved using 5.0 IU xylanase and 4.0 IU pectinase with material to liquid ratio of 1:15 in a 50 mM buffer (glycine-NaOH buffer, 1.0 mM EDTA and 1% Tween-80, pH 8.5) with a treatment time of 60 min at 50 °C and an agitation speed of 60 rpm. The bioscoured cotton fabrics showed a gain of 1.17% in whiteness, 3.23% in brightness and a reduction of 4.18% in yellowness in comparison to fabric scoured with an alkaline scouring method. Further, after bleaching, the whiteness, brightness and tensile strength of the bioscoured fabrics were increased by 2.18, 2.33 and 11.74% along with a decrease of 4.61% in yellowness of bioscoured plus bleached fabrics in comparison to chemically scoured plus bleached fabrics. From the results, it is clear that bioscouring is more efficient, energy saving and an eco-friendly process and has the potential to replace the environment-damaging scouring process with the xylano-pectinolytic bioscouring process.

Process monitoring of additive manufacturing by using optical tomography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zenzinger, Guenter, E-mail: guenter.zenzinger@mtu.de, E-mail: alexander.ladewig@mtu.de; Bamberg, Joachim, E-mail: guenter.zenzinger@mtu.de, E-mail: alexander.ladewig@mtu.de; Ladewig, Alexander, E-mail: guenter.zenzinger@mtu.de, E-mail: alexander.ladewig@mtu.de

2015-03-31

Parts fabricated by means of additive manufacturing are usually of complex shape and owing to the fabrication procedure by using selective laser melting (SLM), potential defects and inaccuracies are often very small in lateral size. Therefore, an adequate quality inspection of such parts is rather challenging, while non-destructive-techniques (NDT) are difficult to realize, but considerable efforts are necessary in order to ensure the quality of SLM-parts especially used for aerospace components. Thus, MTU Aero Engines is currently focusing on the development of an Online Process Control system which monitors and documents the complete welding process during the SLM fabrication procedure.more » A high-resolution camera system is used to obtain images, from which tomographic data for a 3dim analysis of SLM-parts are processed. From the analysis, structural irregularities and structural disorder resulting from any possible erroneous melting process become visible and may be allocated anywhere within the 3dim structure. Results of our optical tomography (OT) method as obtained on real defects are presented.« less

An infiltration/cure model for manufacture of fabric composites by the resin infusion process

NASA Technical Reports Server (NTRS)

Weideman, Mark H.; Loos, Alfred C.; Dexter, H. Benson; Hasko, Gregory H.

1992-01-01

A 1-D infiltration/cure model was developed to simulate fabrication of advanced textile composites by the resin film infusion process. The simulation model relates the applied temperature and pressure processing cycles, along with the experimentally measured compaction and permeability characteristics of the fabric preforms, to the temperature distribution, the resin degree of cure and viscosity, and the infiltration flow front position as a function of time. The model also predicts the final panel thickness, fiber volume fraction, and resin mass for full saturation as a function of compaction pressure. Composite panels were fabricated using the RTM (Resin Transfer Molding) film infusion technique from knitted, knitted/stitched, and 2-D woven carbon preforms and Hercules 3501-6 resin. Fabric composites were fabricated at different compaction pressures and temperature cycles to determine the effects of the processing on the properties. The composites were C-scanned and micrographed to determine the quality of each panel. Advanced cure cycles, developed from the RTM simulation model, were used to reduce the total cure cycle times by a factor of 3 and the total infiltration times by a factor of 2.

A three-dimensional hierarchical collagen scaffold fabricated by a combined solid freeform fabrication (SFF) and electrospinning process to enhance mesenchymal stem cell (MSC) proliferation

NASA Astrophysics Data System (ADS)

Ahn, SeungHyun; Koh, Young Ho; Kim, GeunHyung

2010-06-01

Collagen has the advantage of being very similar to macromolecular substances that can be recognized and metabolized in the biological environment. Although the natural material has superior property for this purpose, its use to fabricate reproducible and pore-structure-controlled 3D structures, which are designed to allow the entry of sufficient cells and the easy diffusion of nutrients, has been limited due to its low processability. Here, we propose a hybrid technology that combines a cryogenic plotting system with an electrospinning process. Using this technique, an easily pore-size-controllable hierarchical 3D scaffold consisting of micro-sized highly porous collagen strands and micro/nano-sized collagen fibers was fabricated. The pore structure of the collagen scaffold was controlled by the collagen micro/nanofibers, which were layered in the scaffold. The hierarchical scaffolds were characterized with respect to initial cell attachment and proliferation of bone marrow-derived mesenchymal stem cells within the scaffolds. The hierarchical scaffold exhibited incredibly enhanced initial cell attachment and cell compactness between pores of the plotted scaffold relative to the normally designed 3D collagen scaffold.

Strengthening of Aluminum Wires Treated with A206/Alumina Nanocomposites

PubMed Central

Marrero, Raúl; Li, Xiaochun; Choi, Hongseok

2018-01-01

This study sought to characterize aluminum nanocomposite wires that were fabricated through a cold-rolling process, having potential applications in TIG (tungsten inert gas) welding of aluminum. A206 (Al-4.5Cu-0.25Mg) master nanocomposites with 5 wt % γAl2O3 nanoparticles were first manufactured through a hybrid process combining semi-solid mixing and ultrasonic processing. A206/1 wt % γAl2O3 nanocomposites were fabricated by diluting the prepared master nanocomposites with a monolithic A206 alloy, which was then added to a pure aluminum melt. The fabricated Al–γAl2O3 nanocomposite billet was cold-rolled to produce an Al nanocomposite wire with a 1 mm diameter and a transverse area reduction of 96%. Containing different levels of nanocomposites, the fabricated samples were mechanically and electrically characterized. The results demonstrate a significantly higher strength of the aluminum wires with the nanocomposite addition. Further, the addition of alumina nanoparticles affected the wires’ electrical conductivity compared with that of pure aluminum and aluminum–copper alloys. The overall properties of the new material demonstrate that these wires could be an appealing alternative for fillers intended for aluminum welding. PMID:29534441

3-D Printing as an Effective Educational Tool for MEMS Design and Fabrication

ERIC Educational Resources Information Center

Dahle, Reena; Rasel, Rafiul

2016-01-01

This paper presents a series of course modules developed as a high-impact and cost-effective learning tool for modeling and simulating the microfabrication process and design of microelectromechanical systems (MEMS) devices using three-dimensional (3-D) printing. Microfabrication technology is an established fabrication technique for small and…

Low-loss 3D-laser-written mid-infrared LiNbO₃ depressed-index cladding waveguides for both TE and TM polarizations.

PubMed

Nguyen, Huu-Dat; Ródenas, Airán; Vázquez de Aldana, Javier R; Martín, Guillermo; Martínez, Javier; Aguiló, Magdalena; Pujol, Maria Cinta; Díaz, Francesc

2017-02-20

We report mid-infrared LiNbO₃ depressed-index microstructured cladding waveguides fabricated by three-dimensional laser writing showing low propagation losses (~1.5 dB/cm) at 3.68 µm wavelength for both the transverse electric and magnetic polarized modes, a feature previously unachieved due to the strong anisotropic properties of this type of laser microstructured waveguides and which is of fundamental importance for many photonic applications. Using a heuristic modeling-testing iteration design approach which takes into account cladding induced stress-optic index changes, the fabricated cladding microstructure provides low-loss single mode operation for the mid-IR for both orthogonal polarizations. The dependence of the localized refractive index changes within the cladding microstructure with post-fabrication thermal annealing processes was also investigated, revealing its complex dependence of the laser induced refractive index changes on laser fabrication conditions and thermal post-processing steps. The waveguide modes properties and their dependence on thermal post-processing were numerically modeled and fitted to the experimental values by systematically varying three fundamental parameters of this type of waveguides: depressed refractive index values at sub-micron laser-written tracks, track size changes, and piezo-optic induced refractive index changes.

A simple method of fabricating mask-free microfluidic devices for biological analysis

PubMed Central

Yi, Xin; Kodzius, Rimantas; Gong, Xiuqing; Xiao, Kang; Wen, Weijia

2010-01-01

We report a simple, low-cost, rapid, and mask-free method to fabricate two-dimensional (2D) and three-dimensional (3D) microfluidic chip for biological analysis researches. In this fabrication process, a laser system is used to cut through paper to form intricate patterns and differently configured channels for specific purposes. Bonded with cyanoacrylate-based resin, the prepared paper sheet is sandwiched between glass slides (hydrophilic) or polymer-based plates (hydrophobic) to obtain a multilayer structure. In order to examine the chip’s biocompatibility and applicability, protein concentration was measured while DNA capillary electrophoresis was carried out, and both of them show positive results. With the utilization of direct laser cutting and one-step gas-sacrificing techniques, the whole fabrication processes for complicated 2D and 3D microfluidic devices are shorten into several minutes which make it a good alternative of poly(dimethylsiloxane) microfluidic chips used in biological analysis researches. PMID:20890452

Overcoming Short-Circuit in Lead-Free CH 3 NH 3 SnI 3 Perovskite Solar Cells via Kinetically Controlled Gas–Solid Reaction Film Fabrication Process

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yokoyama, Takamichi; Cao, Duyen H.; Stoumpos, Constantinos C.

2016-02-17

The development of Sn-based perovskite solar cells has been challenging because devices often show short-circuit behavior due to poor morphologies and undesired electrical properties of the thin films. A low-temperature vapor-assisted solution process (LT-VASP) has been employed as a novel kinetically controlled gas–solid reaction film fabrication method to prepare lead-free CH3NH3SnI3 thin films. We show that the solid SnI2 substrate temperature is the key parameter in achieving perovskite films with high surface coverage and excellent uniformity. The resulting high-quality CH3NH3SnI3 films allow the successful fabrication of solar cells with drastically improved reproducibility, reaching an efficiency of 1.86%. Furthermore, our Kelvinmore » probe studies show the VASP films have a doping level lower than that of films prepared from the conventional one-step method, effectively lowering the film conductivity. Above all, with (LT)-VASP, the short-circuit behavior often obtained from the conventional one-step-fabricated Sn-based perovskite devices has been overcome. This study facilitates the path to more successful Sn-perovskite photovoltaic research.« less

Delta-Doping at Wafer Level for High Throughput, High Yield Fabrication of Silicon Imaging Arrays

NASA Technical Reports Server (NTRS)

Hoenk, Michael E. (Inventor); Nikzad, Shoulch (Inventor); Jones, Todd J. (Inventor); Greer, Frank (Inventor); Carver, Alexander G. (Inventor)

2014-01-01

Systems and methods for producing high quantum efficiency silicon devices. A silicon MBE has a preparation chamber that provides for cleaning silicon surfaces using an oxygen plasma to remove impurities and a gaseous (dry) NH3 + NF3 room temperature oxide removal process that leaves the silicon surface hydrogen terminated. Silicon wafers up to 8 inches in diameter have devices that can be fabricated using the cleaning procedures and MBE processing, including delta doping.

[An experimental research on the fabrication of the fused porcelain to CAD/CAM molar crown].

PubMed

Dai, Ning; Zhou, Yongyao; Liao, Wenhe; Yu, Qing; An, Tao; Jiao, Yiqun

2007-02-01

This paper introduced the fabrication process of the fused porcelain to molar crown with CAD/CAM technology. Firstly, preparation teeth data was retrieved by the 3D-optical measuring system. Then, we have reconstructed the inner surface designed the outer surface shape with the computer aided design software. Finally, the mini high-speed NC milling machine was used to produce the fused porcelain to CAD/CAM molar crown. The result has proved that the fabrication process is reliable and efficient. The dental restoration quality is steady and precise.

"Fabrication of arbitrarily shaped carbonate apatite foam based on the interlocking process of dicalcium hydrogen phosphate dihydrate".

PubMed

Sugiura, Yuki; Tsuru, Kanji; Ishikawa, Kunio

2017-08-01

Carbonate apatite (CO 3 Ap) foam with an interconnected porous structure is highly attractive as a scaffold for bone replacement. In this study, arbitrarily shaped CO 3 Ap foam was formed from α-tricalcium phosphate (α-TCP) foam granules via a two-step process involving treatment with acidic calcium phosphate solution followed by hydrothermal treatment with NaHCO 3 . The treatment with acidic calcium phosphate solution, which is key to fabricating arbitrarily shaped CO 3 Ap foam, enables dicalcium hydrogen phosphate dihydrate (DCPD) crystals to form on the α-TCP foam granules. The generated DCPD crystals cause the α-TCP granules to interlock with each other, inducing an α-TCP/DCPD foam. The interlocking structure containing DCPD crystals can survive hydrothermal treatment with NaHCO 3 . The arbitrarily shaped CO 3 Ap foam was fabricated from the α-TCP/DCPD foam via hydrothermal treatment at 200 °C for 24 h in the presence of a large amount of NaHCO 3 .

Practical Strategies for Integrating Final Ecosystem Goods and ...

EPA Pesticide Factsheets

The concept of Final Ecosystem Goods and Services (FEGS) explicitly connects ecosystem services to the people that benefit from them. This report presents a number of practical strategies for incorporating FEGS, and more broadly ecosystem services, into the decision-making process. Whether a decision process is in early or late stages, or whether a process includes informal or formal decision analysis, there are multiple points where ecosystem services concepts can be integrated. This report uses Structured Decision Making (SDM) as an organizing framework to illustrate the role ecosystem services can play in a values-focused decision-process, including: • Clarifying the decision context: Ecosystem services can help clarify the potential impacts of an issue on natural resources together with their spatial and temporal extent based on supply and delivery of those services, and help identify beneficiaries for inclusion as stakeholders in the deliberative process. • Defining objectives and performance measures: Ecosystem services may directly represent stakeholder objectives, or may be means toward achieving other objectives. • Creating alternatives: Ecosystem services can bring to light creative alternatives for achieving other social, economic, health, or general well-being objectives. • Estimating consequences: Ecosystem services assessments can implement ecological production functions (EPFs) and ecological benefits functions (EBFs) to link decision alt

High Temperature Protonic Conductors

NASA Technical Reports Server (NTRS)

Dynys, Fred; Berger, Marie-Helen; Sayir, Ali

2007-01-01

High Temperature Protonic Conductors (HTPC) with the perovskite structure are envisioned for electrochemical membrane applications such as H2 separation, H2 sensors and fuel cells. Successive membrane commercialization is dependent upon addressing issues with H2 permeation rate and environmental stability with CO2 and H2O. HTPC membranes are conventionally fabricated by solid-state sintering. Grain boundaries and the presence of intergranular second phases reduce the proton mobility by orders of magnitude than the bulk crystalline grain. To enhanced protonic mobility, alternative processing routes were evaluated. A laser melt modulation (LMM) process was utilized to fabricate bulk samples, while pulsed laser deposition (PLD) was utilized to fabricate thin film membranes . Sr3Ca(1+x)Nb(2-x)O9 and SrCe(1-x)Y(x)O3 bulk samples were fabricated by LMM. Thin film BaCe(0.85)Y(0.15)O3 membranes were fabricated by PLD on porous substrates. Electron microscopy with chemical mapping was done to characterize the resultant microstructures. High temperature protonic conduction was measured by impedance spectroscopy in wet air or H2 environments. The results demonstrate the advantage of thin film membranes to thick membranes but also reveal the negative impact of defects or nanoscale domains on protonic conductivity.

Advanced fabrication of Si nanowire FET structures by means of a parallel approach.

PubMed

Li, J; Pud, S; Mayer, D; Vitusevich, S

2014-07-11

In this paper we present fabricated Si nanowires (NWs) of different dimensions with enhanced electrical characteristics. The parallel fabrication process is based on nanoimprint lithography using high-quality molds, which facilitates the realization of 50 nm-wide NW field-effect transistors (FETs). The imprint molds were fabricated by using a wet chemical anisotropic etching process. The wet chemical etch results in well-defined vertical sidewalls with edge roughness (3σ) as small as 2 nm, which is about four times better compared with the roughness usually obtained for reactive-ion etching molds. The quality of the mold was studied using atomic force microscopy and scanning electron microscopy image data. The use of the high-quality mold leads to almost 100% yield during fabrication of Si NW FETs as well as to an exceptional quality of the surfaces of the devices produced. To characterize the Si NW FETs, we used noise spectroscopy as a powerful method for evaluating device performance and the reliability of structures with nanoscale dimensions. The Hooge parameter of fabricated FET structures exhibits an average value of 1.6 × 10(-3). This value reflects the high quality of Si NW FETs fabricated by means of a parallel approach that uses a nanoimprint mold and cost-efficient technology.

Hybrid 3D printing by bridging micro/nano processes

NASA Astrophysics Data System (ADS)

Yoon, Hae-Sung; Jang, Ki-Hwan; Kim, Eunseob; Lee, Hyun-Taek; Ahn, Sung-Hoon

2017-06-01

A hybrid 3D printing process was developed for multiple-material/freeform nano-scale manufacturing. The process consisted of aerodynamically focused nanoparticle (AFN) printing, micro-machining, focused ion beam milling, and spin-coating. Theoretical and experimental investigations were carried out to improve the compatibility of each of the processes, enabling bridging of various different techniques. The resulting hybrid process could address the limitations of individual processes, enabling improved process scaling and dimensional degrees of freedom, without losing the advantages of the existing processes. The minimum structure width can be reduced to 50 nm using undercut structures. In addition, AFN printing employs particle impact for adhesion, and various inorganic materials are suitable for printing, including metals and functional ceramics. Using the developed system, we fabricated bi-material cantilevers for applications as a thermal actuator. The mechanical and thermal properties of the structure were investigated using an in situ measurement system, and irregular thermal phenomena due to the fabrication process were analyzed. We expect that this work will lead to improvements in the area of customized nano-scale manufacturing, as well as further improvements in manufacturing technology by combining different fabrication techniques.

Improved performance of organic solar cells with solution processed hole transport layer

NASA Astrophysics Data System (ADS)

Bhargav, Ranoo; Gairola, S. P.; Patra, Asit; Naqvi, Samya; Dhawan, S. K.

2018-06-01

This work is based on Cobalt Oxide as solution processed, inexpensive and effective hole transport layer (HTL) for efficient organic photovoltaic applications (OPVs). In Organic solar cell (OSC) devices ITO coated glass substrate used as a transparent anode electrode for light incident, HTL material Co3O4 dissolve in DMF solvent deposited on anode electrode, after that active layer material (donor/acceptor) deposited on to HTL and finally Al were deposited by thermal evaporation used as cathode electrode. These devices were fabricated with PCDTBT well known low band gap donor material in OSCs and blended with PC71BM as an acceptor material using simplest device structure ITO/Co3O4/active layer/Al at ambient conditions. The power conversion efficiencies (PCEs) based on Co3O4 and PEDOT:PSS have been achieved to up to 3.21% and 1.47% with PCDTBT respectively. In this study we reported that the devices fabricated with Co3O4 showed better performance as compare to the devices fabricated with well known and most studied solution processed HTL material PEDOT:PSS under identical environmental conditions. The surface morphology of the HTL film was characterized by (AFM). Lastly, we have provided Co3O4 as an efficient hole transport material HTL for solution processed organic photovoltaic applications.

SU-E-T-04: 3D Dose Based Patient Compensator QA Procedure for Proton Radiotherapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zou, W; Reyhan, M; Zhang, M

2015-06-15

Purpose: In proton double-scattering radiotherapy, compensators are the essential patient specific devices to contour the distal dose distribution to the tumor target. Traditional compensator QA is limited to checking the drilled surface profiles against the plan. In our work, a compensator QA process was established that assess the entire compensator including its internal structure for patient 3D dose verification. Methods: The fabricated patient compensators were CT scanned. Through mathematical image processing and geometric transformations, the CT images of the proton compensator were combined with the patient simulation CT images into a new series of CT images, in which the imagedmore » compensator is placed at the planned location along the corresponding beam line. The new CT images were input into the Eclipse treatment planning system. The original plan was calculated to the combined CT image series without the plan compensator. The newly computed patient 3D dose from the combined patientcompensator images was verified against the original plan dose. Test plans include the compensators with defects intentionally created inside the fabricated compensators. Results: The calculated 3D dose with the combined compensator and patient CT images reflects the impact of the fabricated compensator to the patient. For the test cases in which no defects were created, the dose distributions were in agreement between our method and the corresponding original plans. For the compensator with the defects, the purposely changed material and a purposely created internal defect were successfully detected while not possible with just the traditional compensator profiles detection methods. Conclusion: We present here a 3D dose verification process to qualify the fabricated proton double-scattering compensator. Such compensator detection process assesses the patient 3D impact of the fabricated compensator surface profile as well as the compensator internal material and structure changes. This research receives funding support from CURA Medical Technologies.« less

A rapid, straightforward, and print house compatible mass fabrication method for integrating 3D paper-based microfluidics.

PubMed

Xiao, Liangpin; Liu, Xianming; Zhong, Runtao; Zhang, Kaiqing; Zhang, Xiaodi; Zhou, Xiaomian; Lin, Bingcheng; Du, Yuguang

2013-11-01

Three-dimensional (3D) paper-based microfluidics, which is featured with high performance and speedy determination, promise to carry out multistep sample pretreatment and orderly chemical reaction, which have been used for medical diagnosis, cell culture, environment determination, and so on with broad market prospect. However, there are some drawbacks in the existing fabrication methods for 3D paper-based microfluidics, such as, cumbersome and time-consuming device assembly; expensive and difficult process for manufacture; contamination caused by organic reagents from their fabrication process. Here, we present a simple printing-bookbinding method for mass fabricating 3D paper-based microfluidics. This approach involves two main steps: (i) wax-printing, (ii) bookbinding. We tested the delivery capability, diffusion rate, homogeneity and demonstrated the applicability of the device to chemical analysis by nitrite colorimetric assays. The described method is rapid (<30 s), cheap, easy to manipulate, and compatible with the flat stitching method that is common in a print house, making itself an ideal scheme for large-scale production of 3D paper-based microfluidics. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Fabrication of Trabecular Bone-Templated Tissue-Engineered Constructs by 3D Inkjet Printing.

PubMed

Vanderburgh, Joseph P; Fernando, Shanik J; Merkel, Alyssa R; Sterling, Julie A; Guelcher, Scott A

2017-11-01

3D printing enables the creation of scaffolds with precisely controlled morphometric properties for multiple tissue types, including musculoskeletal tissues such as cartilage and bone. Computed tomography (CT) imaging has been combined with 3D printing to fabricate anatomically scaled patient-specific scaffolds for bone regeneration. However, anatomically scaled scaffolds typically lack sufficient resolution to recapitulate the <100 micrometer-scale trabecular architecture essential for investigating the cellular response to the morphometric properties of bone. In this study, it is hypothesized that the architecture of trabecular bone regulates osteoblast differentiation and mineralization. To test this hypothesis, human bone-templated 3D constructs are fabricated via a new micro-CT/3D inkjet printing process. It is shown that this process reproducibly fabricates bone-templated constructs that recapitulate the anatomic site-specific morphometric properties of trabecular bone. A significant correlation is observed between the structure model index (a morphometric parameter related to surface curvature) and the degree of mineralization of human mesenchymal stem cells, with more concave surfaces promoting more extensive osteoblast differentiation and mineralization compared to predominately convex surfaces. These findings highlight the significant effects of trabecular architecture on osteoblast function. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Crystallization Dynamics of Organolead Halide Perovskite by Real-Time X-ray Diffraction.

PubMed

Miyadera, Tetsuhiko; Shibata, Yosei; Koganezawa, Tomoyuki; Murakami, Takurou N; Sugita, Takeshi; Tanigaki, Nobutaka; Chikamatsu, Masayuki

2015-08-12

We analyzed the crystallization process of the CH3NH3PbI3 perovskite by observing real-time X-ray diffraction immediately after combining a PbI2 thin film with a CH3NH3I solution. A detailed analysis of the transformation kinetics demonstrated the fractal diffusion of the CH3NH3I solution into the PbI2 film. Moreover, the perovskite crystal was found to be initially oriented based on the PbI2 crystal orientation but to gradually transition to a random orientation. The fluctuating characteristics of the crystallization process of perovskites, such as fractal penetration and orientational transformation, should be controlled to allow the fabrication of high-quality perovskite crystals. The characteristic reaction dynamics observed in this study should assist in establishing reproducible fabrication processes for perovskite solar cells.

Fluidic Processing of High-Performance ZIF-8 Membranes on Polymeric Hollow Fibers: Mechanistic Insights and Microstructure Control

DOE PAGES

Eum, Kiwon; Rownaghi, Ali; Choi, Dalsu; ...

2016-06-01

Recently, a methodology for fabricating polycrystalline metal-organic framework (MOF) membranes has been introduced – referred to as interfacial microfluidic membrane processing – which allows parallelizable fabrication of MOF membranes inside polymeric hollow fibers of microscopic diameter. Such hollow fiber membranes, when bundled together into modules, are an attractive way to scale molecular sieving membranes. The understanding and engineering of fluidic processing techniques for MOF membrane fabrication are in their infancy. Here in this work, a detailed mechanistic understanding of MOF (ZIF-8) membrane growth under microfluidic conditions in polyamide-imide hollow fibers is reported, without any intermediate steps (such as seeding ormore » surface modification) or post-synthesis treatments. A key finding is that interfacial membrane formation in the hollow fiber occurs via an initial formation of two distinct layers and the subsequent rearrangement into a single layer. This understanding is used to show how nonisothermal processing allows fabrication of thinner (5 μm) ZIF-8 films for higher throughput, and furthermore how engineering the polymeric hollow fiber support microstructure allows control of defects in the ZIF-8 membranes. Finally, the performance of these engineered ZIF-8 membranes is then characterized, which have H 2/C 3H 8 and C 3H 6/C 3H 8 mixture separation factors as high as 2018 and 65, respectively, and C 3H 6 permeances as high as 66 GPU.« less

Scalable fabrication of efficient organolead trihalide perovskite solar cells with doctor-bladed active layers

DOE PAGES

Deng, Yehao; Peng, Edwin; Shao, Yuchuan; ...

2015-03-25

Organolead trihalide perovskites (OTPs) are nature abundant materials with prospects as future low-cost renewable energy sources boosted by the solution process capability of these materials. Here we report the fabrication of efficient OTP devices by a simple, high throughput and low-cost doctor-blade coating process which can be compatible with the roll-to-roll fabrication process for the large scale production of perovskite solar cell panels. The formulation of appropriate precursor inks by removing impurities is shown to be critical in the formation of continuous, pin-hole free and phase-pure perovskite films on large area substrates, which is assisted by a high deposition temperaturemore » to guide the nucleation and grain growth process. The domain size reached 80–250 μm in 1.5–2 μm thick bladed films. By controlling the stoichiometry and thickness of the OTP films, highest device efficiencies of 12.8% and 15.1% are achieved in the devices fabricated on poly(3,4-ethylenedioxythiophene) polystyrene sulfonate and cross-linked N4,N4'-bis(4-(6-((3-ethyloxetan-3-yl)methoxy)hexyl)phenyl)–N4,N4'-diphenylbiphenyl-4,4'-diamine covered ITO substrates. Furthermore, the carrier diffusion length in doctor-bladed OTP films is beyond 3.5 μm which is significantly larger than in the spin-coated films, due to the formation of crystalline grains with a very large size by the doctor-blade coating method.« less

Configurable 3D-Printed millifluidic and microfluidic 'lab on a chip' reactionware devices.

PubMed

Kitson, Philip J; Rosnes, Mali H; Sans, Victor; Dragone, Vincenza; Cronin, Leroy

2012-09-21

We utilise 3D design and 3D printing techniques to fabricate a number of miniaturised fluidic 'reactionware' devices for chemical syntheses in just a few hours, using inexpensive materials producing reliable and robust reactors. Both two and three inlet reactors could be assembled, as well as one-inlet devices with reactant 'silos' allowing the introduction of reactants during the fabrication process of the device. To demonstrate the utility and versatility of these devices organic (reductive amination and alkylation reactions), inorganic (large polyoxometalate synthesis) and materials (gold nanoparticle synthesis) processes were efficiently carried out in the printed devices.

3D-printed microfluidic chips with patterned, cell-laden hydrogel constructs.

PubMed

Knowlton, Stephanie; Yu, Chu Hsiang; Ersoy, Fulya; Emadi, Sharareh; Khademhosseini, Ali; Tasoglu, Savas

2016-06-20

Three-dimensional (3D) printing offers potential to fabricate high-throughput and low-cost fabrication of microfluidic devices as a promising alternative to traditional techniques which enables efficient design iterations in the development stage. In this study, we demonstrate a single-step fabrication of a 3D transparent microfluidic chip using two alternative techniques: a stereolithography-based desktop 3D printer and a two-step fabrication using an industrial 3D printer based on polyjet technology. This method, compared to conventional fabrication using relatively expensive materials and labor-intensive processes, presents a low-cost, rapid prototyping technique to print functional 3D microfluidic chips. We enhance the capabilities of 3D-printed microfluidic devices by coupling 3D cell encapsulation and spatial patterning within photocrosslinkable gelatin methacryloyl (GelMA). The platform presented here serves as a 3D culture environment for long-term cell culture and growth. Furthermore, we have demonstrated the ability to print complex 3D microfluidic channels to create predictable and controllable fluid flow regimes. Here, we demonstrate the novel use of 3D-printed microfluidic chips as controllable 3D cell culture environments, advancing the applicability of 3D printing to engineering physiological systems for future applications in bioengineering.

The fabrication of small molecule organic light-emitting diode pixels by laser-induced forward transfer

NASA Astrophysics Data System (ADS)

Shaw-Stewart, J. R. H.; Mattle, T.; Lippert, T. K.; Nagel, M.; Nüesch, F. A.; Wokaun, A.

2013-01-01

Laser-induced forward transfer (LIFT) is a versatile organic light-emitting diode (OLED) pixel deposition process, but has hitherto been applied exclusively to polymeric materials. Here, a modified LIFT process has been used to fabricate small molecule Alq3 organic light-emitting diodes (SMOLEDs). Small molecule thin films are considerably more mechanically brittle than polymeric thin films, which posed significant challenges for LIFT of these materials. The LIFT process presented here uses a polymeric dynamic release layer, a reduced environmental pressure, and a well-defined receiver-donor gap. The Alq3 pixels demonstrate good morphology and functionality, even when compared to conventionally fabricated OLEDs. The Alq3 SMOLED pixel performances show a significant amount of fluence dependence, not observed with polymerical OLED pixels made in previous studies. A layer of tetrabutyl ammonium hydroxide has been deposited on top of the aluminium cathode, as part of the donor substrate, to improve electron injection to the Alq3, by over 600%. These results demonstrate that this variant of LIFT is applicable for the deposition of functional small molecule OLEDs as well as polymeric OLEDs.

Development of Cotton Fabrics with Durable UV Protective and Self-cleaning Property by Deposition of Low TiO2 Levels through Sol-gel Process.

PubMed

Mishra, Anu; Butola, Bhupendra Singh

2018-01-19

In this article, the deposition of TiO 2 on cotton fabric using sol-gel technique has been described. Various process routes (pad-dry-cure, pad-dry-hydrothermal and pad-dry-solvothermal) were examined to impart a stable coating of TiO 2 on fabric. The role of precursor concentration, process temperature and time of treatment were studied to aim at a wash durable, UV protective and self-cleaning property in the treated fabric. EDX and ICP-MS techniques were used to examine the add-on percentage of TiO 2 on cotton fabrics treated via different routes. It has been found that the TiO 2 remains largely amorphous and nondurable if it is given a short thermal treatment. To convert the deposited TiO 2 to its anatase crystal form, a prolonged hydrothermal treatment for at least 3 h needs to be given. TiO 2 deposition levels of less than 0.1% were found to be effective in imparting reasonable degree of UV protection and self-cleaning property to the cotton fabric. The self-cleaning ability of the treated fabric against coffee stain was also studied and was found to be related to the process route and the deposition levels of TiO 2 . © 2018 The American Society of Photobiology.

The potential effectiveness of the nutrition improvement program on infant and young child feeding and nutritional status in the Northwest and Southwest regions of Cameroon, Central Africa.

PubMed

Reinsma, Kate; Nkuoh, Godlove; Nshom, Emmanuel

2016-11-15

Despite the recent international focus on maternal and child nutrition, little attention is paid to nutrition capacity development. Although infant feeding counselling by health workers increases caregivers' knowledge, and improves breastfeeding, complementary feeding, and children's linear growth, most of the counselling in sub-Saharan Africa is primarily conducted by nurses or volunteers, and little is done to develop capacity for nutrition at the professional, organizational, or systemic levels. The Cameroon Baptist Convention Health Services Nutrition Improvement Program (NIP) has integrated a cadre of nutrition counselors into prevention of mother-to-child transmission of HIV programs, infant welfare clinics, and antenatal clinics to improve infant and young child feeding practices (IYCF). The study objective was to evaluate the effects of NIP's infant feeding counselors on exclusive breastfeeding (EBF), complementary feeding (CF), and children's linear growth. A cross-sectional evaluation design was used. Using systematic random sampling, caregivers were recruited from NIP sites (n = 359) and non-NIP sites (n = 415) from Infant Welfare Clinics (IWCs) in the Northwest (NWR) and Southwest Regions (SWR) of Cameroon between October 2014 and April 2015. Differences in EBF and CF practices and children's linear growth between NIP and non-NIP sites were determined using chi-square and multiple logistic regression. After adjusting for differences in religion, occupation, and number of months planning to breastfeed, children were almost seven times (Odds Ratio [OR]: 6.9; 95% Confidence Interval [CI]: 2.30, 21.09; β = 1.94) more likely to be exclusively breastfed at NIP sites compared to non-NIP sites. After adjusting for differences in occupation, religion, number of months planning to breastfeed, rural environment, economic status, attending other Infant Welfare Clinics, and non-biological caregiver, children were five times more likely to be stunted at non-NIP sites compared to NIP sites. Training a cadre of nutrition counselors is one approach towards increasing nutrition human resources to implement nutrition interventions to improve maternal and child nutrition. In this research project, the study design did not allow for conclusive results, but rather suggest IYCF counseling provided by nutrition counselors was effective in increasing EBF and reduced the risk of stunting in children 6-8 months.

Improved Method of Manufacturing SiC Devices

NASA Technical Reports Server (NTRS)

Okojie, Robert S.

2005-01-01

The phrase, "common-layered architecture for semiconductor silicon carbide" ("CLASSiC") denotes a method of batch fabrication of microelectromechanical and semiconductor devices from bulk silicon carbide. CLASSiC is the latest in a series of related methods developed in recent years in continuing efforts to standardize SiC-fabrication processes. CLASSiC encompasses both institutional and technological innovations that can be exploited separately or in combination to make the manufacture of SiC devices more economical. Examples of such devices are piezoresistive pressure sensors, strain gauges, vibration sensors, and turbulence-intensity sensors for use in harsh environments (e.g., high-temperature, high-pressure, corrosive atmospheres). The institutional innovation is to manufacture devices for different customers (individuals, companies, and/or other entities) simultaneously in the same batch. This innovation is based on utilization of the capability for fabrication, on the same substrate, of multiple SiC devices having different functionalities (see figure). Multiple customers can purchase shares of the area on the same substrate, each customer s share being apportioned according to the customer s production-volume requirement. This makes it possible for multiple customers to share costs in a common foundry, so that the capital equipment cost per customer in the inherently low-volume SiC-product market can be reduced significantly. One of the technological innovations is a five-mask process that is based on an established set of process design rules. The rules provide for standardization of the fabrication process, yet are flexible enough to enable multiple customers to lay out masks for their portions of the SiC substrate to provide for simultaneous batch fabrication of their various devices. In a related prior method, denoted multi-user fabrication in silicon carbide (MUSiC), the fabrication process is based largely on surface micromachining of poly SiC. However, in MUSiC one cannot exploit the superior sensing, thermomechanical, and electrical properties of single-crystal 6H-SiC or 4H-SiC. As a complement to MUSiC, the CLASSiC five-mask process can be utilized to fabricate multiple devices in bulk single-crystal SiC of any polytype. The five-mask process makes fabrication less complex because it eliminates the need for large-area deposition and removal of sacrificial material. Other innovations in CLASSiC pertain to selective etching of indium tin oxide and aluminum in connection with multilayer metallization. One major characteristic of bulk micromachined microelectromechanical devices is the presence of three-dimensional (3D) structures. Any 3D recesses that already exist at a given step in a fabrication process usually make it difficult to apply a planar coat of photoresist for metallization and other subsequent process steps. To overcome this difficulty, the CLASSiC process includes a reversal of part of the conventional flow: Metallization is performed before the recesses are etched.

Green piezoelectric for autonomous smart textile

NASA Astrophysics Data System (ADS)

Lemaire, E.; Borsa, C. J.; Briand, D.

2015-12-01

In this work, the fabrication of Rochelle salt based piezoelectric textiles are shown. Structures composed of fibers and Rochelle salt are easily produced using green processes. Both manufacturing and the material itself are really efficient in terms of environmental impact, considering the fabrication processes and the material resources involved. Additionally Rochelle salt is biocompatible. In this green paradigm, active sensing or actuating textiles are developed. Thus processing method and piezoelectric properties have been studied: (1) pure crystals are used as acoustic actuator, (2) fabrication of the textile-based composite is detailed, (3) converse effective d33 is evaluated and compared to lead zirconate titanate ceramic. The utility of textile-based piezoelectric merits its use in a wide array of applications.

Fabrication of polymer/cadmium sulfide hybrid solar cells [P3HT:CdS and PCPDTBT:CdS] by spray deposition.

PubMed

Kumar, Neetesh; Dutta, Viresh

2014-11-15

This paper investigates fabrication of surfactant free CdS nanoparticles (NPs) and application in the fabrication of P3HT:CdS and PCPDTBT:CdS bulk-heterojunction hybrid solar cells using high-throughput, large-area, low cost spray deposition technique. Both the hybrid active layers and hole transport layers are deposited by spray technique. The CdS/Poly(3-hexylthiophene-2,5-diyl) (P3HT) and CdS/Poly[2,6-(4,4-bis-(2-ethylhexyl)-4H-cyclopenta[2,1-b;3,4-b']dithiophene)-alt-4,7(2,1,3-benzothiadiazole)] (PCPDTBT) hybrid devices are fabricated by spray deposition process at optimized conditions (i.e. film thickness, spray solution volume, distance between sample and spray nozzle, substrate temperature, etc.). The power conversion efficiency of η=0.6% and 1.02% is obtained for P3HT:CdS and PCPDTBT:CdS hybrid devices, respectively. Spray coating holds significant promise as a technique capable of fabricating large-area, high performance hybrid solar cells. Copyright © 2014 Elsevier Inc. All rights reserved.

3D-glass molds for facile production of complex droplet microfluidic chips.

PubMed

Tovar, Miguel; Weber, Thomas; Hengoju, Sundar; Lovera, Andrea; Munser, Anne-Sophie; Shvydkiv, Oksana; Roth, Martin

2018-03-01

In order to leverage the immense potential of droplet microfluidics, it is necessary to simplify the process of chip design and fabrication. While polydimethylsiloxane (PDMS) replica molding has greatly revolutionized the chip-production process, its dependence on 2D-limited photolithography has restricted the design possibilities, as well as further dissemination of microfluidics to non-specialized labs. To break free from these restrictions while keeping fabrication straighforward, we introduce an approach to produce complex multi-height (3D) droplet microfluidic glass molds and subsequent chip production by PDMS replica molding. The glass molds are fabricated with sub-micrometric resolution using femtosecond laser machining technology, which allows directly realizing designs with multiple levels or even continuously changing heights. The presented technique significantly expands the experimental capabilities of the droplet microfluidic chip. It allows direct fabrication of multilevel structures such as droplet traps for prolonged observation and optical fiber integration for fluorescence detection. Furthermore, the fabrication of novel structures based on sloped channels (ramps) enables improved droplet reinjection and picoinjection or even a multi-parallelized drop generator based on gradients of confinement. The fabrication of these and other 3D-features is currently only available at such resolution by the presented strategy. Together with the simplicity of PDMS replica molding, this provides an accessible solution for both specialized and non-specialized labs to customize microfluidic experimentation and expand their possibilities.

A Theoretical Model for Predicting Residual Stress Generation in Fabrication Process of Double-Ceramic-Layer Thermal Barrier Coating System.

PubMed

Song, Yan; Wu, Weijie; Xie, Feng; Liu, Yilun; Wang, Tiejun

2017-01-01

Residual stress arisen in fabrication process of Double-Ceramic-Layer Thermal Barrier Coating System (DCL-TBCs) has a significant effect on its quality and reliability. In this work, based on the practical fabrication process of DCL-TBCs and the force and moment equilibrium, a theoretical model was proposed at first to predict residual stress generation in its fabrication process, in which the temperature dependent material properties of DCL-TBCs were incorporated. Then, a Finite Element method (FEM) has been carried out to verify our theoretical model. Afterwards, some important geometric parameters for DCL-TBCs, such as the thickness ratio of stabilized Zirconia (YSZ, ZrO2-8%Y2O3) layer to Lanthanum Zirconate (LZ, La2Zr2O7) layer, which is adjustable in a wide range in the fabrication process, have a remarkable effect on its performance, therefore, the effect of this thickness ratio on residual stress generation in the fabrication process of DCL-TBCs has been systematically studied. In addition, some thermal spray treatment, such as the pre-heating treatment, its effect on residual stress generation has also been studied in this work. It is found that, the final residual stress mainly comes from the cooling down process in the fabrication of DCL-TBCs. Increasing the pre-heating temperature can obviously decrease the magnitude of residual stresses in LZ layer, YSZ layer and substrate. With the increase of the thickness ratio of YSZ layer to LZ layer, magnitudes of residual stresses arisen in LZ layer and YSZ layer will increase while residual stress in substrate will decrease.

A Theoretical Model for Predicting Residual Stress Generation in Fabrication Process of Double-Ceramic-Layer Thermal Barrier Coating System

PubMed Central

Song, Yan; Wu, Weijie; Xie, Feng; Liu, Yilun; Wang, Tiejun

2017-01-01

Residual stress arisen in fabrication process of Double-Ceramic-Layer Thermal Barrier Coating System (DCL-TBCs) has a significant effect on its quality and reliability. In this work, based on the practical fabrication process of DCL-TBCs and the force and moment equilibrium, a theoretical model was proposed at first to predict residual stress generation in its fabrication process, in which the temperature dependent material properties of DCL-TBCs were incorporated. Then, a Finite Element method (FEM) has been carried out to verify our theoretical model. Afterwards, some important geometric parameters for DCL-TBCs, such as the thickness ratio of stabilized Zirconia (YSZ, ZrO2-8%Y2O3) layer to Lanthanum Zirconate (LZ, La2Zr2O7) layer, which is adjustable in a wide range in the fabrication process, have a remarkable effect on its performance, therefore, the effect of this thickness ratio on residual stress generation in the fabrication process of DCL-TBCs has been systematically studied. In addition, some thermal spray treatment, such as the pre-heating treatment, its effect on residual stress generation has also been studied in this work. It is found that, the final residual stress mainly comes from the cooling down process in the fabrication of DCL-TBCs. Increasing the pre-heating temperature can obviously decrease the magnitude of residual stresses in LZ layer, YSZ layer and substrate. With the increase of the thickness ratio of YSZ layer to LZ layer, magnitudes of residual stresses arisen in LZ layer and YSZ layer will increase while residual stress in substrate will decrease. PMID:28103275

Fabrication of fuel pin assemblies, phase 3

NASA Technical Reports Server (NTRS)

Keeton, A. R.; Stemann, L. G.

1972-01-01

Five full size and eight reduced length fuel pins were fabricated for irradiation testing to evaluate design concepts for a fast spectrum lithium cooled compact space power reactor. These assemblies consisted of uranium mononitride fuel pellets encased in a T-111 (Ta-8W-2Hf) clad with a tungsten barrier separating fuel and clad. Fabrication procedures were fully qualified by process development and assembly qualification tests. Detailed specifications and procedures were written for the fabrication and assembly of prototype fuel pins.

Single domain YBa2Cu3Oy thick films on metallic substrates

NASA Astrophysics Data System (ADS)

Reddy, E. S.; Noudem, J. G.; Goodilin, E. A.; Tarka, M.; Schmitz, G. J.

2003-03-01

The fabrication of single domain YBa2Cu3Oy (123) thick films (10-100 mum) on metallic substrates is reported. The process involves the formation of the 123 phase by a peritectic reaction between an air-brushed dense Y2BaCuO5 (211) layer on a Ag12Pd substrate and infiltrated liquid phases containing barium cuprates and copper oxides. Single domain growth is achieved by seeding the green films with a c-axis oriented NdBa2Cu3Oy crystal prior to processing. The maximum processing temperatures are lowered to 970 °C by modifying the characteristics of the liquid phases meant for infiltration by addition of Ag powder. The fabrication technique, processing conditions for single domain growth and the resulting microstructures are discussed.

Fabrication and characterization of WO3/Ag/WO3 multilayer transparent anode with solution-processed WO3 for polymer light-emitting diodes

PubMed Central

2012-01-01

The dielectric/metal/dielectric multilayer is suitable for a transparent electrode because of its high-optical and high-electrical properties; however, it is fabricated by an expensive and inefficient multistep vacuum process. We present a WO3/Ag/WO3 (WAW) multilayer transparent anode with solution-processed WO3 for polymer light-emitting diodes (PLEDs). This WAW multilayer not only has high transmittance and low resistance but also can be easily and rapidly fabricated. We devised a novel method to deposit a thin WO3 layer by a solution process in an air environment. A tungstic acid solution was prepared from an aqueous solution of Na2WO4 and then converted to WO3 nanoparticles (NPs) by a thermal treatment. Thin WO3 NP layers form WAW multilayer with a thermal-evaporated Ag layer, and they improve the transmittance of the WAW multilayer because of its high transmittance and refractive index. Moreover, the surface of the WO3 layer is homogeneous and flat with low roughness because of the WO3 NP generation from the tungstic acid solution without aggregation. We performed optical simulation and experiments, and the optimized WAW multilayer had a high transmittance of 85% with a sheet resistance of 4 Ω/sq. Finally, PLEDs based on the WAW multilayer anode achieved a maximum luminance of 35,550 cd/m2 at 8 V, and this result implies that the solution-processed WAW multilayer is appropriate for use as a transparent anode in PLEDs. PMID:22587669

Fabrication and characterization of WO3/Ag/WO3 multilayer transparent anode with solution-processed WO3 for polymer light-emitting diodes.

PubMed

Jeon, Kangmin; Youn, Hongseok; Kim, Seongbeom; Shin, Seongbeom; Yang, Minyang

2012-05-15

The dielectric/metal/dielectric multilayer is suitable for a transparent electrode because of its high-optical and high-electrical properties; however, it is fabricated by an expensive and inefficient multistep vacuum process. We present a WO3/Ag/WO3 (WAW) multilayer transparent anode with solution-processed WO3 for polymer light-emitting diodes (PLEDs). This WAW multilayer not only has high transmittance and low resistance but also can be easily and rapidly fabricated. We devised a novel method to deposit a thin WO3 layer by a solution process in an air environment. A tungstic acid solution was prepared from an aqueous solution of Na2WO4 and then converted to WO3 nanoparticles (NPs) by a thermal treatment. Thin WO3 NP layers form WAW multilayer with a thermal-evaporated Ag layer, and they improve the transmittance of the WAW multilayer because of its high transmittance and refractive index. Moreover, the surface of the WO3 layer is homogeneous and flat with low roughness because of the WO3 NP generation from the tungstic acid solution without aggregation. We performed optical simulation and experiments, and the optimized WAW multilayer had a high transmittance of 85% with a sheet resistance of 4 Ω/sq. Finally, PLEDs based on the WAW multilayer anode achieved a maximum luminance of 35,550 cd/m2 at 8 V, and this result implies that the solution-processed WAW multilayer is appropriate for use as a transparent anode in PLEDs.

A strategy for design and fabrication of low cost microchannel for future reproductivity of bio/chemical lab-on-chip application

NASA Astrophysics Data System (ADS)

Humayun, Q.; Hashim, U.; Ruzaidi, C. M.; Noriman, N. Z.

2017-03-01

The fabrication and characterization of sensitive and selective fluids delivery system for the application of nano laboratory on a single chip is a challenging task till to date. This paper is one of the initial attempt to resolve this challenging task by using a simple, cost effective and reproductive technique for pattering a microchannel structures on SU-8 resist. The objective of the research is to design, fabricate and characterize polydimethylsiloxane (PDMS) microchannel. The proposed device mask was designed initially by using AutoCAD software and then the designed was transferred to transparency sheet and to commercial chrome mask for better photo masking process. The standard photolithography process coupled with wet chemical etching process was used for the fabrication of proposed microchannel. This is a low cost fabrication technique for the formation of microchannel structure at resist. The fabrication process start from microchannel formation and then the structure was transformed to PDMS substrate, the microchannel structure was cured from mold and then the cured mold was bonded with the glass substrate by plasma oxidation bonding process. The surface morphology was characterized by high power microscope (HPM) and the structure was characterized by Hawk 3 D surface nanoprofiler. The next part of the research will be focus onto device testing and validation by using real biological samples by the implementation of a simple manual injection technique.

Recent Advances in 3D Printing of Aliphatic Polyesters.

PubMed

Chiulan, Ioana; Frone, Adriana Nicoleta; Brandabur, Călin; Panaitescu, Denis Mihaela

2017-12-24

3D printing represents a valuable alternative to traditional processing methods, clearly demonstrated by the promising results obtained in the manufacture of various products, such as scaffolds for regenerative medicine, artificial tissues and organs, electronics, components for the automotive industry, art objects and so on. This revolutionary technique showed unique capabilities for fabricating complex structures, with precisely controlled physical characteristics, facile tunable mechanical properties, biological functionality and easily customizable architecture. In this paper, we provide an overview of the main 3D-printing technologies currently employed in the case of poly (lactic acid) (PLA) and polyhydroxyalkanoates (PHA), two of the most important classes of thermoplastic aliphatic polyesters. Moreover, a short presentation of the main 3D-printing methods is briefly discussed. Both PLA and PHA, in the form of filaments or powder, proved to be suitable for the fabrication of artificial tissue or scaffolds for bone regeneration. The processability of PLA and PHB blends and composites fabricated through different 3D-printing techniques, their final characteristics and targeted applications in bioengineering are thoroughly reviewed.

ITRB Spar Domestic Source

DTIC Science & Technology

2012-12-14

Each pair of rollers is designed to capture the shafts mounted to both ends of the tool lid. Additionally, a safety pin can be put in place to...ITRB for the AH-64D. The scope of the program included structural design , materials selection, manufacturing producibility analysis, tooling design ...responsible for tooling design and fabrication, fabrication process development and fabrication of spars and test samples; G3 who designed the RTM

Fabrication of Natural Uranium UO 2 Disks (Phase II): Texas A&M Work for Others Summary Document

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gerczak, Tyler J.; Baldwin, Charles A.; Schmidlin, Joshua E.

The steps to fabricate natural UO 2 disks for an irradiation campaign led by Texas A&M University are outlined. The process was initiated with stoichiometry adjustment of parent, U 3O 8 powder. The next stage of sample preparation involved exploratory pellet pressing and sintering to achieve the desired natural UO 2 pellet densities. Ideal densities were achieved through the use of a bimodal powder size blend. The steps involved with disk fabrication are also presented, describing the coring and thinning process executed to achieve final dimensionality.

Evaluation and rational design of guide RNAs for efficient CRISPR/Cas9-mediated mutagenesis in Ciona

PubMed Central

Gandhi, Shashank; Haeussler, Maximilian; Razy-Krajka, Florian; Christiaen, Lionel; Stolfi, Alberto

2017-01-01

The CRISPR/Cas9 system has emerged as an important tool for various genome engineering applications. A current obstacle to high throughput applications of CRISPR/Cas9 is the imprecise prediction of highly active single guide RNAs (sgRNAs). We previously implemented the CRISPR/Cas9 system to induce tissue-specific mutations in the tunicate Ciona. In the present study, we designed and tested 83 single guide RNA (sgRNA) vectors targeting 23 genes expressed in the cardiopharyngeal progenitors and surrounding tissues of Ciona embryo. Using high-throughput sequencing of mutagenized alleles, we identified guide sequences that correlate with sgRNA mutagenesis activity and used this information for the rational design of all possible sgRNAs targeting the Ciona transcriptome. We also describe a one-step cloning-free protocol for the assembly of sgRNA expression cassettes. These cassettes can be directly electroporated as unpurified PCR products into Ciona embryos for sgRNA expression in vivo, resulting in high frequency of CRISPR/Cas9-mediated mutagenesis in somatic cells of electroporated embryos. We found a strong correlation between the frequency of an Ebf loss-of-function phenotype and the mutagenesis efficacies of individual Ebf-targeting sgRNAs tested using this method. We anticipate that our approach can be scaled up to systematically design and deliver highly efficient sgRNAs for the tissue-specific investigation of gene functions in Ciona. PMID:28341547

Superenhancer reprogramming drives a B-cell–epithelial transition and high-risk leukemia

PubMed Central

Hu, Yeguang; Zhang, Zhihong; Kashiwagi, Mariko; Yoshida, Toshimi; Joshi, Ila; Jena, Nilamani; Somasundaram, Rajesh; Emmanuel, Akinola Olumide; Sigvardsson, Mikael; Fitamant, Julien; El-Bardeesy, Nabeel; Gounari, Fotini; Van Etten, Richard A.; Georgopoulos, Katia

2016-01-01

IKAROS is required for the differentiation of highly proliferative pre-B-cell precursors, and loss of IKAROS function indicates poor prognosis in precursor B-cell acute lymphoblastic leukemia (B-ALL). Here we show that IKAROS regulates this developmental stage by positive and negative regulation of superenhancers with distinct lineage affiliations. IKAROS defines superenhancers at pre-B-cell differentiation genes together with B-cell master regulators such as PAX5, EBF1, and IRF4 but is required for a highly permissive chromatin environment, a function that cannot be compensated for by the other transcription factors. IKAROS is also highly enriched at inactive enhancers of genes normally expressed in stem–epithelial cells. Upon IKAROS loss, expression of pre-B-cell differentiation genes is attenuated, while a group of extralineage transcription factors that are directly repressed by IKAROS and depend on EBF1 relocalization at their enhancers for expression is induced. LHX2, LMO2, and TEAD–YAP1, normally kept separate from native B-cell transcription regulators by IKAROS, now cooperate directly with them in a de novo superenhancer network with its own feed-forward transcriptional reinforcement. Induction of de novo superenhancers antagonizes Polycomb repression and superimposes aberrant stem–epithelial cell properties in a B-cell precursor. This dual mechanism of IKAROS regulation promotes differentiation while safeguarding against a hybrid stem–epithelial–B-cell phenotype that underlies high-risk B-ALL. PMID:27664237

Microstructure and inclusion of Ti-6Al-4V fabricated by selective laser melting

NASA Astrophysics Data System (ADS)

Huang, Qianli; Hu, Ningmin; Yang, Xing; Zhang, Ranran; Feng, Qingling

2016-12-01

Selective laser melting (SLM) was used in fabricating the dense part from pre-alloyed Ti-6Al-4V powder. The microstructural evolution and inclusion formation of as-fabricated part were characterized in depth. The microstructure was characterized by features of columnar prior β grains and acicular martensite α'. High density defects such as dislocations and twins can be produced in SLM process. Investigations on the inclusions find out that hard alpha inclusion, amorphous CaO and microcrystalline Al2O3 are three main inclusions formed in SLM. The inclusions formed at some specific sites on melt pool surface. The microstructural evolution and inclusion formation of as-fabricated material are closely related to the SLM process.

Investigation of radiation shielding properties for MeO-PbCl2-TeO2 (MeO = Bi2O3, MoO3, Sb2O3, WO3, ZnO) glasses

NASA Astrophysics Data System (ADS)

Sayyed, M. I.; Çelikbilek Ersundu, M.; Ersundu, A. E.; Lakshminarayana, G.; Kostka, P.

2018-03-01

In this work, glasses in the MeO-PbCl2-TeO2 (MeO = Bi2O3, MoO3, Sb2O3, WO3, ZnO) system, which show a great potential for optoelectronic applications, were used to evaluate their resistance under high energy ionizing radiations. The basic shielding quantities for determining the penetration of radiation in glass, such as mass attenuation coefficient (μ/ρ), half value layer (HVL), mean free path (MFP) and exposure buildup factor (EBF) values were investigated within the energy range 0.015 MeV ‒ 15 MeV using XCOM program and variation of shielding parameters were compared with different glass systems and ordinary concrete. From the derived results, it was determined that MeO-PbCl2-TeO2 (MeO = Bi2O3, MoO3, Sb2O3, WO3, ZnO) glasses show great potentiality to be used under high energy radiations. Among the studied glass compositions, Bi2O3 and WO3 containing glasses were found to possess superior gamma-ray shielding effectiveness.

Unidirectional Fabric Drape Testing Method

PubMed Central

Mei, Zaihuan; Yang, Jingzhi; Zhou, Ting; Zhou, Hua

2015-01-01

In most cases, fabrics such as curtains, skirts, suit pants and so on are draped under their own gravity parallel to fabric plane while the gravity is perpendicular to fabric plane in traditional drape testing method. As a result, it does not conform to actual situation and the test data is not convincing enough. To overcome this problem, this paper presents a novel method which simulates the real mechanical conditions and ensures the gravity is parallel to the fabric plane. This method applied a low-cost Kinect Sensor device to capture the 3-dimensional (3D) drape profile, thus we obtained the drape degree parameters and aesthetic parameters by 3D reconstruction and image processing and analysis techniques. The experiment was conducted on our self-devised drape-testing instrument by choosing different kinds of weave structure fabrics as our testing samples and the results were compared with those of traditional method and subjective evaluation. Through regression and correlation analysis we found that this novel testing method was significantly correlated with the traditional and subjective evaluation method. We achieved a new, non-contact 3D measurement method for drape testing, namely unidirectional fabric drape testing method. This method is more suitable for evaluating drape behavior because it is more in line with actual mechanical conditions of draped fabrics and has a well consistency with the requirements of visual and aesthetic style of fabrics. PMID:26600387

Electrothermally-Actuated Micromirrors with Bimorph Actuators--Bending-Type and Torsion-Type.

PubMed

Tsai, Cheng-Hua; Tsai, Chun-Wei; Chang, Hsu-Tang; Liu, Shih-Hsiang; Tsai, Jui-Che

2015-06-22

Three different electrothermally-actuated MEMS micromirrors with Cr/Au-Si bimorph actuators are proposed. The devices are fabricated with the SOIMUMPs process developed by MEMSCAP, Inc. (Durham, NC, USA). A silicon-on-insulator MEMS process has been employed for the fabrication of these micromirrors. Electrothermal actuation has achieved a large angular movement in the micromirrors. Application of an external electric current 0.04 A to the bending-type, restricted-torsion-type, and free-torsion-type mirrors achieved rotation angles of 1.69°, 3.28°, and 3.64°, respectively.

Demonstration of the feasibility of automated silicon solar cell fabrication

NASA Technical Reports Server (NTRS)

Taylor, W. E.; Schwartz, F. M.

1975-01-01

A study effort was undertaken to determine the process, steps and design requirements of an automated silicon solar cell production facility. Identification of the key process steps was made and a laboratory model was conceptually designed to demonstrate the feasibility of automating the silicon solar cell fabrication process. A detailed laboratory model was designed to demonstrate those functions most critical to the question of solar cell fabrication process automating feasibility. The study and conceptual design have established the technical feasibility of automating the solar cell manufacturing process to produce low cost solar cells with improved performance. Estimates predict an automated process throughput of 21,973 kilograms of silicon a year on a three shift 49-week basis, producing 4,747,000 hexagonal cells (38mm/side), a total of 3,373 kilowatts at an estimated manufacturing cost of $0.866 per cell or $1.22 per watt.

Additive manufacturing of lab-on-a-chip devices: promises and challenges

NASA Astrophysics Data System (ADS)

Zhu, Feng; Macdonald, Niall P.; Cooper, Jonathan M.; Wlodkowic, Donald

2013-12-01

This work describes a preliminary investigation of commercially available 3D printing technologies for rapid prototyping and low volume fabrication of Lab-on-a-Chip devices. The main motivation of the work was to use off-the-shelf 3D printing methods in order to rapidly and inexpensively build microfluidic devices with complex geometric features and reduce the need to use clear room environment and conventional microfabrication techniques. Both multi-jet modelling (MJM) and stereolithography (SLA) processes were explored. MJM printed devices were fabricated using a HD3500+ (3D Systems) high-definition printer using a thermo-polymer VisiJet Crystal (3D Systems) substratum that allows for a z-axis resolution of 16 μm and 25 μm x-y accuracy. SLA printed devices were produced using a Viper Pro (3D Systems) stereolithography system using Watershed 11122XC (DSM Somos) and Dreve Fototec 7150 Clear (Dreve Otoplastik GmbH) resins which allow for a z-axis resolution of 50 μm and 25 μm x-y accuracy. Fabrication results compared favourably with other forms of rapid prototyping such as laser cut PMMA devices and PDMS moulded microfluidic devices of the same design. Both processes allowed for fabrication of monolithic, optically transparent devices with features in the 100 μm range requiring minimal post-processing. Optical polymer qualities following different post-processing methods were also tested in both brightfield and fluorescence imaging of transgenic zebrafish embryos. Finally, we show that only ethanol-treated Dreve Fototec 7150 Clear resign proved to be non-toxic to human cell lines and fish embryos in fish toxicity assays (FET) requiring further investigation of 3D printing materials.

Bio-inspired piezoelectric artificial hair cell sensor fabricated by powder injection molding

NASA Astrophysics Data System (ADS)

Han, Jun Sae; Oh, Keun Ha; Moon, Won Kyu; Kim, Kyungseop; Joh, Cheeyoung; Seo, Hee Seon; Bollina, Ravi; Park, Seong Jin

2015-12-01

A piezoelectric artificial hair cell sensor was fabricated by the powder injection molding process in order to make an acoustic vector hydrophone. The entire process of powder injection molding was developed and optimized for PMN-PZT ceramic powder. The artificial hair cell sensor, which consists of high aspect ratio hair cell and three rectangular mechanoreceptors, was precisely fabricated through the developed powder injection molding process. The density and the dielectric property of the fabricated sensor shows 98% of the theoretical density and 85% of reference dielectric property of PMN-PZT ceramic powder. With regard to homogeneity, three rectangular mechanoreceptors have the same dimensions, with 3 μm of tolerance with 8% of deviation of dielectric property. Packaged vector hydrophones measure the underwater acoustic signals from 500 to 800 Hz with -212 dB of sensitivity. Directivity of vector hydrophone was acquired at 600 Hz as analyzing phase differences of electric signals.

Near-field photochemical and radiation-induced chemical fabrication of nanopatterns of a self-assembled silane monolayer

PubMed Central

Hentschel, Carsten; Fontein, Florian; Stegemann, Linda; Hoeppener, Christiane; Fuchs, Harald; Hoeppener, Stefanie

2014-01-01

Summary A general concept for parallel near-field photochemical and radiation-induced chemical processes for the fabrication of nanopatterns of a self-assembled monolayer (SAM) of (3-aminopropyl)triethoxysilane (APTES) is explored with three different processes: 1) a near-field photochemical process by photochemical bleaching of a monomolecular layer of dye molecules chemically bound to an APTES SAM, 2) a chemical process induced by oxygen plasma etching as well as 3) a combined near-field UV-photochemical and ozone-induced chemical process, which is applied directly to an APTES SAM. All approaches employ a sandwich configuration of the surface-supported SAM, and a lithographic mask in form of gold nanostructures fabricated through colloidal sphere lithography (CL), which is either exposed to visible light, oxygen plasma or an UV–ozone atmosphere. The gold mask has the function to inhibit the photochemical reactions by highly localized near-field interactions between metal mask and SAM and to inhibit the radiation-induced chemical reactions by casting a highly localized shadow. The removal of the gold mask reveals the SAM nanopattern. PMID:25247126

Improved performance of mesostructured perovskite solar cells via an anti-solvent method

NASA Astrophysics Data System (ADS)

Hao, Jiabin; Hao, Huiying; Cheng, Feiyu; Li, Jianfeng; Zhang, Haiyu; Dong, Jingjing; Xing, Jie; Liu, Hao; Wu, Jian

2018-06-01

One-step solution process is a facile and widely used procedure to prepare organic-inorganic perovskite materials. However, the poor surface morphology of the films attributed to the uncontrollable nucleation and crystal growth in the process is unfavorable to solar cells. In this study, an anti-solvent treatment during the one-step solution process, in which ethyl acetate (EA) was dropped on the sample during spinning the precursor solution containing CH3NH3Cl, was adopted to fabricate perovskite materials and solar cells. It was found that the morphology of the perovskite film was significantly improved due to the rapid nucleation and slow crystal growth process. The modified process enabled us to fabricate the mesoporous solar cell with power conversion efficiency of 14%, showing an improvement of 40% over the efficiency of 9.7% of the device prepared by conventional one-step method. The controlling effect of annealing time on the morphology, crystal structure and transport properties of perovskite layer as well as the performance of device fabricated by the anti-solvent method were investigated and the possible mechanism was discussed.

End-of-fabrication CMOS process monitor

NASA Technical Reports Server (NTRS)

Buehler, M. G.; Allen, R. A.; Blaes, B. R.; Hannaman, D. J.; Lieneweg, U.; Lin, Y.-S.; Sayah, H. R.

1990-01-01

A set of test 'modules' for verifying the quality of a complementary metal oxide semiconductor (CMOS) process at the end of the wafer fabrication is documented. By electrical testing of specific structures, over thirty parameters are collected characterizing interconnects, dielectrics, contacts, transistors, and inverters. Each test module contains a specification of its purpose, the layout of the test structure, the test procedures, the data reduction algorithms, and exemplary results obtained from 3-, 2-, or 1.6-micrometer CMOS/bulk processes. The document is intended to establish standard process qualification procedures for Application Specific Integrated Circuits (ASIC's).

3D printing scanning electron microscopy sample holders: A quick and cost effective alternative for custom holder fabrication.

PubMed

Meloni, Gabriel N; Bertotti, Mauro

2017-01-01

A simple and cost effective alternative for fabricating custom Scanning Electron Microscope (SEM) sample holders using 3D printers and conductive polylactic acid filament is presented. The flexibility of the 3D printing process allowed for the fabrication of sample holders with specific features that enable the high-resolution imaging of nanoelectrodes and nanopipettes. The precise value of the inner semi cone angle of the nanopipettes taper was extracted from the acquired images and used for calculating their radius using electrochemical methods. Because of the low electrical resistivity presented by the 3D printed holder, the imaging of non-conductive nanomaterials, such as alumina powder, was found to be possible. The fabrication time for each sample holder was under 30 minutes and the average cost was less than $0.50 per piece. Despite being quick and economical to fabricate, the sample holders were found to be sufficiently resistant, allowing for multiple uses of the same holder.

3D printing scanning electron microscopy sample holders: A quick and cost effective alternative for custom holder fabrication

PubMed Central

Bertotti, Mauro

2017-01-01

A simple and cost effective alternative for fabricating custom Scanning Electron Microscope (SEM) sample holders using 3D printers and conductive polylactic acid filament is presented. The flexibility of the 3D printing process allowed for the fabrication of sample holders with specific features that enable the high-resolution imaging of nanoelectrodes and nanopipettes. The precise value of the inner semi cone angle of the nanopipettes taper was extracted from the acquired images and used for calculating their radius using electrochemical methods. Because of the low electrical resistivity presented by the 3D printed holder, the imaging of non-conductive nanomaterials, such as alumina powder, was found to be possible. The fabrication time for each sample holder was under 30 minutes and the average cost was less than $0.50 per piece. Despite being quick and economical to fabricate, the sample holders were found to be sufficiently resistant, allowing for multiple uses of the same holder. PMID:28753638

The effects of processing techniques on magnesium-based composite

NASA Astrophysics Data System (ADS)

Rodzi, Siti Nur Hazwani Mohamad; Zuhailawati, Hussain

2016-12-01

The aim of this study is to investigate the effect of processing techniques on the densification, hardness and compressive strength of Mg alloy and Mg-based composite for biomaterial application. The control sample (pure Mg) and Mg-based composite (Mg-Zn/HAp) were fabricated through mechanical alloying process using high energy planetary mill, whilst another Mg-Zn/HAp composite was fabricated through double step processing (the matrix Mg-Zn alloy was fabricated by planetary mill, subsequently HAp was dispersed by roll mill). As-milled powder was then consolidated by cold press into 10 mm diameter pellet under 400 MPa compaction pressure before being sintered at 300 °C for 1 hour under the flow of argon. The densification of the sintered pellets were then determined by Archimedes principle. Mechanical properties of the sintered pellets were characterized by microhardness and compression test. The results show that the density of the pellets was significantly increased by addition of HAp, but the most optimum density was observed when the sample was fabricated through double step processing (1.8046 g/cm3). Slight increment in hardness and ultimate compressive strength were observed for Mg-Zn/HAp composite that was fabricated through double step processing (58.09 HV, 132.19 MPa), as compared to Mg-Zn/HAp produced through single step processing (47.18 HV, 122.49 MPa).

Low-Temperature UV-Assisted Fabrication of Metal Oxide Thin Film Transistor

NASA Astrophysics Data System (ADS)

Zhu, Shuanglin

Solution processed metal oxide semiconductors have attracted intensive attention in the last several decades and have emerged as a promising candidate for the application of thin film transistor (TFT) due to their nature of transparency, flexibility, high mobility, simple processing technique and potential low manufacturing cost. However, metal oxide thin film fabricated by solution process usually requires a high temperature (over 300 °C), which is above the glass transition temperature of some conventional polymer substrates. In order to fabricate the flexible electronic device on polymer substrates, it is necessary to find a facile approach to lower the fabrication temperature and minimize defects in metal oxide thin film. In this thesis, the electrical properties dependency on temperature is discussed and an UV-assisted annealing method incorporating Deep ultraviolet (DUV)-decomposable additives is demonstrated, which can effectively improve electrical properties solution processed metal oxide semiconductors processed at temperature as low as 220 °C. By studying a widely used indium oxide (In2O3) TFT as a model system, it is worth noted that compared with the sample without UV treatment, the linear mobility and saturation mobility of UV-annealing sample are improved by 56% and 40% respectively. Meanwhile, the subthreshold swing is decreased by 32%, indicating UV-treated device could turn on and off more efficiently. In addition to pure In2O3 film, the similar phenomena have also been observed in indium oxide based Indium-Gallium-Zinc Oxide (IGZO) system. These finding presented in this thesis suggest that the UV assisted annealing process open a new route to fabricate high performance metal oxide semiconductors under low temperatures.

Infant feeding practices and determinants of poor breastfeeding behavior in Kinshasa, Democratic Republic of Congo: a descriptive study.

PubMed

Yotebieng, Marcel; Chalachala, Jean Lambert; Labbok, Miriam; Behets, Frieda

2013-10-01

Although breastfeeding is almost universally accepted in the Democratic Republic (DR) of Congo, by the age of 2 to 3 months 65% of children are receiving something other than human milk. We sought to describe the infant feeding practices and determinants of suboptimal breastfeeding behaviors in DR Congo. Survey questionnaire administered to mothers of infants aged ≤ 6 months and healthcare providers who were recruited consecutively at six selected primary health care facilities in Kinshasa, the capital. All 66 mothers interviewed were breastfeeding. Before initiating breastfeeding, 23 gave their infants something other than their milk, including: sugar water (16) or water (2). During the twenty-four hours prior to interview, 26 (39%) infants were exclusively breastfed (EBF), whereas 18 (27%), 12 (18%), and 10 (15%) received water, tea, formula, or porridge, respectively, in addition to human milk. The main reasons for water supplementation included "heat" and cultural beliefs that water is needed for proper digestion of human milk. The main reason for formula supplementation was the impression that the baby was not getting enough milk; and for porridge supplementation, the belief that the child was old enough to start complementary food. Virtually all mothers reported that breastfeeding was discussed during antenatal clinic visit and half reported receiving help regarding breastfeeding from a health provider either after birth or during well-child clinic visit. Despite a median of at least 14 years of experience in these facilities, healthcare workers surveyed had little to no formal training on how to support breastfeeding and inadequate breastfeeding-related knowledge and skills. The facilities lacked any written policy about breastfeeding. Addressing cultural beliefs, training healthcare providers adequately on breastfeeding support skills, and providing structured breastfeeding support after maternity discharge is needed to promote EBF in the DR Congo.

River Induced Wellbore Flow Dynamics in Long-Screen Wells and their Impact on Aqueous Sampling Results

NASA Astrophysics Data System (ADS)

Vermeul, V.; McKinley, J. P.; Newcomer, D.; Fritz, B. G.; Mackley, R.; Zachara, J. M.

2010-12-01

Previously published field investigations and modeling studies have demonstrated the potential for sample bias associated with vertical wellbore flow in conventional monitoring wells constructed with long-screened intervals. In this study, simultaneous measurement of 1) wellbore flow using an electromagnetic borehole flowmeter (EBF), 2) depth discrete hydraulic head, and 3) aqueous uranium concentrations were used to quantify wellbore flow and assess the associated impacts on measured aqueous concentrations. Monitoring results demonstrate the utility of continuous (i.e., hourly measurements for ~ one month) ambient wellbore flow monitoring and show that relatively large wellbore flows (up to 4 LPM) can be induced by aquifer hydrodynamics associated with a fluctuating river boundary located approximately 250 m from the test well. The observed vertical wellbore flows were strongly correlated with fluctuations in river stage, alternating between upward and downward flow throughout the monitoring period in response to changes in river stage. Continuous monitoring of ambient wellbore flows using an EBF system allowed these effects to be evaluated in concert with continuously monitored river stage elevations (hourly) and aqueous uranium concentrations (daily) in a long-screen well and an adjacent multi-level well cluster. This study demonstrates that when contaminant concentrations within the aquifer vary significantly over the depth interval interrogated, river-induced vertical wellbore flow can result in variations in measured concentration that nearly encompass the full range of variation in aquifer contaminant concentration with depth. In addition, observed variability in aqueous concentrations measured during active tracer transport experiments provided additional evidence of wellbore flow impacts and showed that the magnitude and direction of wellbore flow varied spatially across the wellfield. An approach to mitigate these effects based on increasing hydraulic resistance within the wellbore was evaluated. This research is part of the ERSP Hanford IFRC at Pacific Northwest National Laboratory.

Pad ultrasonic batch dyeing of causticized lyocell fabric with reactive dyes.

PubMed

Babar, Aijaz Ahmed; Peerzada, Mazhar Hussain; Jhatial, Abdul Khalique; Bughio, Noor-Ul-Ain

2017-01-01

Conventionally, cellulosic fabric dyed with reactive dyes requires significant amount of salt. However, the dyeing of a solvent spun regenerated cellulosic fiber is a critical process. This paper presents the dyeing results of lyocell fabrics dyed with conventional pad batch (CPB) and pad ultrasonic batch (PUB) processes. The dyeing of lyocell fabrics was carried out with two commercial dyes namely Drimarine Blue CL-BR and Ramazol Blue RGB. Dyeing parameters including concentration of sodium hydroxide, sodium carbonate and dwell time were compared for the two processes. The outcomes show that PUB dyed samples offered reasonably higher color yield and dye fixation than CPB dyed samples. A remarkable reduction of 12h in batching time, 18ml/l in NaOH and 05g/l in Na 2 CO 3 quantity was observed for PUB processed samples producing similar results compared to CPB process, making PUB a more economical, productive and an environment friendly process. Color fastness examination witnessed identical results for both PUB and CPB methods. No significant change in surface morphology of PUB processed samples was observed through scanning electron microscope (SEM) analysis. Copyright © 2016 Elsevier B.V. All rights reserved.

3D food printing: a new dimension in food production processes

USDA-ARS?s Scientific Manuscript database

3D food printing, also known as food layered manufacture (FLM), is an exciting new method of digital food production that applies the process of additive manufacturing to food fabrication. In the 3D food printing process, a food product is first scanned or designed with computer-aided design softwa...

Rapid wasted-free microfluidic fabrication based on ink-jet approach for microfluidic sensing applications

NASA Astrophysics Data System (ADS)

Jarujareet, Ungkarn; Amarit, Rattasart; Sumriddetchkajorn, Sarun

2016-11-01

Realizing that current microfluidic chip fabrication techniques are time consuming and labor intensive as well as always have material leftover after chip fabrication, this research work proposes an innovative approach for rapid microfluidic chip production. The key idea relies on a combination of a widely-used inkjet printing method and a heat-based polymer curing technique with an electronic-mechanical control, thus eliminating the need of masking and molds compared to typical microfluidic fabrication processes. In addition, as the appropriate amount of polymer is utilized during printing, there is much less amount of material wasted. Our inkjet-based microfluidic printer can print out the desired microfluidic chip pattern directly onto a heated glass surface, where the printed polymer is suddenly cured. Our proof-of-concept demonstration for widely-used single-flow channel, Y-junction, and T-junction microfluidic chips shows that the whole microfluidic chip fabrication process requires only 3 steps with a fabrication time of 6 minutes.

Development of Impregnated Agglomerate Pelletization (IAP) process for fabrication of (Th,U)O 2 mixed oxide pellets

NASA Astrophysics Data System (ADS)

Khot, P. M.; Nehete, Y. G.; Fulzele, A. K.; Baghra, Chetan; Mishra, A. K.; Afzal, Mohd.; Panakkal, J. P.; Kamath, H. S.

2012-01-01

Impregnated Agglomerate Pelletization (IAP) technique has been developed at Advanced Fuel Fabrication Facility (AFFF), BARC, Tarapur, for manufacturing (Th, 233U)O 2 mixed oxide fuel pellets, which are remotely fabricated in hot cell or shielded glove box facilities to reduce man-rem problem associated with 232U daughter radionuclides. This technique is being investigated to fabricate the fuel for Indian Advanced Heavy Water Reactor (AHWR). In the IAP process, ThO 2 is converted to free flowing spheroids by powder extrusion route in an unshielded facility which are then coated with uranyl nitrate solution in a shielded facility. The dried coated agglomerate is finally compacted and then sintered in oxidizing/reducing atmosphere to obtain high density (Th,U)O 2 pellets. In this study, fabrication of (Th,U)O 2 mixed oxide pellets containing 3-5 wt.% UO 2 was carried out by IAP process. The pellets obtained were characterized using optical microscopy, XRD and alpha autoradiography. The results obtained were compared with the results for the pellets fabricated by other routes such as Coated Agglomerate Pelletization (CAP) and Powder Oxide Pelletization (POP) route.

Advanced Fabrication Processes for Superconducting Very Large Scale Integrated Circuits

DTIC Science & Technology

2015-10-13

transistors. There are several reasons for this gigantic disparity: insufficient funding and lack of profit-driven investments in superconductor ...Inductance of circuit structures for MIT LL superconductor electronics fabrication process with 8 niobium layers,” IEEE Trans. Appl. Supercond., vol...vol. 25, No. 3, 1301704, June 2015. [7] V. Ambegaokar and A. Baratoff, “Tunneling between superconductors ,” Phys. Rev. Lett., vol. 10, no. 11, pp

Infusion Processing of Phenylethynyl Terminated Imides by High Temperature RTM and VARTM

NASA Technical Reports Server (NTRS)

Ghose, Sayata; Lewis, Todd M.; Cano, Roberto J.; Watson, Kent A.; Isayev, Avraam I.

2011-01-01

Fabrication of composite structures using infusion processes such as resin transfer molding (RTM) and vacuum assisted resin transfer molding (VARTM) is generally more affordable than conventional autoclave techniques. Recent efforts have focused on adapting both technologies for the fabrication of high temperature (HT) resistant composites. Due to their low melt viscosity and long melt stability, certain phenylethynyl terminated imides (PETI) can be processed into composites using these high temperature out-of-autoclave processes. In the current study, two PETI resins, LARC(TradeMark) PETI-330 and LARC(TradeMark) PETI-8 have been used to make test specimens using both RTM and VARTM. For aerospace applications, a void fraction of less than 2% is desired. Traditionally, RTM has had the advantage over VARTM for generating composites with low void content. However, the process is limited in terms of size. Work at NASA LaRC has incorporated modifications to the thermal cycle used in laminate fabrication that have reduced the void content significantly (typically 1-3%) using the current HT-VARTM process. For composite fabrication by both RTM and VARTM, the resins were infused into three carbon fiber preforms (T650-35-3k 5HS, IM7-6k 5HS, and IM7-6k Uniweave) at 316 C and 260 C respectively and cured up to 371 C. The details of the RTM processing carried out at the University of Akron are discussed in this work along with a brief description of the HT-VARTM processing carried out at NASA-LaRC. Photomicrographs of the panels were taken and void contents were determined by acid digestion. Mechanical properties (short beam shear, SBS) of the panels fabricated by both infusion processes were determined at room temperature as well as at various elevated temperatures. The results of this work are presented herein.

Fabrication of a customized bone scaffold using a homemade medical 3D printer for comminuted fractures

NASA Astrophysics Data System (ADS)

Yoon, Do-Kun; Jung, Joo-Young; Shin, Han-Back; Kim, Moo-Sub; Choe, Bo-Young; Kim, Sunmi; Suh, Tae Suk; Lee, Keum Sil; Xing, Lei

2016-09-01

The purpose of this study was to show a 3D printed reconstruction model of a bone destroyed by a comminuted fracture. After a thoracic limb of a cow with a comminuted fracture was scanned by using computed tomography, a scaffold was designed by using a 3D modeling tool for its reconstruction and fabricated by using a homemade medical 3D printer. The homemade medical 3D printer was designed for medical use. In order to reconstruct the geometry of the destroyed bone, we use the geometry of a similar section (reference geometry) of normal bone in the 3D modeling process. The missing part between the destroyed ridge and the reference geometry was filled with an effective space by using a manual interpolation. Inexpensive materials and free software were used to construct the medical 3D printer system. The fabrication of the scaffold progressed according to the design of reconstructed bone by using this medical 3D printer. The material of the scaffold was biodegradable material, and could be transplanted into the human body. The fabricated scaffold was correctly inserted into the fractured bone in place of the destroyed portion, with good agreement. According to physical stress test results, the performance of printing resolution was 0.1 mm. The average geometrical error of the scaffold was below 0.3 mm. The reconstructed bone by using the fabricated scaffold was able to support the weight of the human body. No process used to obtain the result was complex or required many resources. The methods and results in this study show several possible clinical applications in fields such as orthopedics or oncology without a need to purchase high-price instruments for 3D printing.

Crashworthiness Assessment of Auto-body Members Considering the Fabrication Histories

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huh, Hoon; Song, Jung-Han; Kim, Kee-Poong

2005-08-05

This paper is concerned with crashworthiness of auto-body members considering the effect of fabrication. Most auto-body members are fabricated with sheet metal forming process and welding process that induce fabrication histories such as the plastic work hardening, non-uniform thickness distribution and residual stress. Crash simulation is carried out for auto-body members with LS-DYNA3D in order to identify the fabrication effect on the crashworthiness. The analysis calculated crash mode, the reaction force and the energy absorption for crashworthiness assessment with the forming effect. The result shows that the crash analysis with considering the forming history leads to a different result frommore » that without considering the forming effect. The analysis results demonstrate that the design of auto-body members should be carried out considering the forming history for accurate assessment of the crashworthiness.« less

2D all-solid state fabric supercapacitor fabricated via an all solution process for use in smart textiles

NASA Astrophysics Data System (ADS)

Jang, Yunseok; Jo, Jeongdai; Woo, Kyoohee; Lee, Seung-Hyun; Kwon, Sin; Kim, Kwang-Young; Kang, Dongwoo

2017-05-01

We propose a method to fabricate a supercapacitor for smart textiles using silver (Ag) nanoparticle (NP) ink, simple spray patterning systems, and intense pulsed light (IPL) sintering systems. The Ag NP current collectors provided as high conductivity as the metal current collectors. The spray patterning technique is useful for fabricating supercapacitors because it is simple, fast, and cheap. IPL systems reduced the sintering temperature of Ag NPs and prevented thermal damage to the textiles during the Ag NP sintering process. The two-dimensional (2D) all-solid state fabric supercapacitor with an interdigitated configuration, developed here, exhibited a specific capacitance of 25.7 F/g and an energy density of 1.5 Wh/kg at a power density of 64.3 W/kg. These results support the utility of our proposed method in the development of energy textiles.

Powder-Coated Towpreg: Avenues to Near Net Shape Fabrication of High Performance Composites

NASA Technical Reports Server (NTRS)

Johnston, N. J.; Cano, R. J.; Marchello, J. M.; Sandusky, D. A.

1995-01-01

Near net shape parts were fabricated from powder-coated preforms. Key issues including powder loss during weaving and tow/tow friction during braiding were addressed, respectively, by fusing the powder to the fiber prior to weaving and applying a water-based gel to the towpreg prior to braiding. A 4:1 debulking of a complex 3-D woven powder-coated preform was achieved in a single step utilizing expansion rubber molding. Also, a process was developed for using powder-coated towpreg to fabricate consolidated ribbon having good dimensional integrity and low voids. Such ribbon will be required for in situ fabrication of structural components via heated head advanced tow placement. To implement process control and ensure high quality ribbon, the ribbonizer heat transfer and pulling force were modeled from fundamental principles. Most of the new ribbons were fabricated from dry polyarylene ether and polymide powders.

New database for improving virtual system “body-dress”

NASA Astrophysics Data System (ADS)

Yan, J. Q.; Zhang, S. C.; Kuzmichev, V. E.; Adolphe, D. C.

2017-10-01

The aim of this exploration is to develop a new database of solid algorithms and relations between the dress fit and the fabric mechanical properties, the pattern block construction for improving the reality of virtual system “body-dress”. In virtual simulation, the system “body-clothing” sometimes shown distinct results with reality, especially when important changes in pattern block and fabrics were involved. In this research, to enhance the simulation process, diverse fit parameters were proposed: bottom height of dress, angle of front center contours, air volume and its distribution between dress and dummy. Measurements were done and optimized by ruler, camera, 3D body scanner image processing software and 3D modeling software. In the meantime, pattern block indexes were measured and fabric properties were tested by KES. Finally, the correlation and linear regression equations between indexes of fabric properties, pattern blocks and fit parameters were investigated. In this manner, new database could be extended in programming modules of virtual design for more realistic results.

Influence of wholesale lamb marketing options and merchandising styles on retail yield and fabrication time.

PubMed

Lorenzen, C L; Martin, A M; Griffin, D B; Dockerty, T R; Walter, J P; Johnson, H K; Savell, J W

1997-01-01

Lamb carcasses (n = 94) from five packing plants, selected to vary in weight class and fat thickness, were used to determine retail yield and labor requirements of wholesale lamb fabrication. Carcasses were allotted randomly according to weight class to be fabricated as whole carcasses (n = 20), three-piece boxes (n = 22), or subprimals (n = 52). Processing times (seconds) were recorded and wholesale and retail weights (kilograms) were obtained to calculate retail yield. Subprimals were fabricated into bone-in retail cuts or boneless or semi-boneless retail cuts. Retail yield for subprimal lamb legs decreased from 85.3 +/- .6% for bone-in to 68.0 +/- .7% for a completely boneless retail product. Correspondingly, processing times increased from 126.1 +/- 5.4 s to 542.0 +/- 19.2 s for bone-in and boneless legs, respectively. For all subprimals, retail yield percentage tended to decrease and total processing time increase as cuts were fabricated to boneless or semi-boneless end points compared with a bone-in end point. Percentage retail yield did not differ (P > .05) among whole carcass, three-piece box, and subprimal marketing methods. Total processing time was shorter for subprimals (P < .05) than for the other two marketing methods.

Novel laser-processed CsI:Tl detector for SPECT

PubMed Central

Sabet, H.; Bläckberg, L.; Uzun-Ozsahin, D.; El-Fakhri, G.

2016-01-01

Purpose: The aim of this work is to demonstrate the feasibility of a novel technique for fabrication of high spatial resolution CsI:Tl scintillation detectors for single photon emission computed tomography systems. Methods: The scintillators are fabricated using laser-induced optical barriers technique to create optical microstructures (or optical barriers) inside the CsI:Tl crystal bulk. The laser-processed CsI:Tl crystals are 3, 5, and 10 mm in thickness. In this work, the authors focus on the simplest pattern of optical barriers in that the barriers are created in the crystal bulk to form pixel-like patterns resembling mechanically pixelated scintillators. The monolithic CsI:Tl scintillator samples are fabricated with optical barrier patterns with 1.0 × 1.0 mm2 and 0.625 × 0.625 mm2 pixels. Experiments were conducted to characterize the fabricated arrays in terms of pixel separation and energy resolution. A 4 × 4 array of multipixel photon counter was used to collect the scintillation light in all the experiments. Results: The process yield for fabricating the CsI:Tl arrays is 100% with processing time under 50 min. From the flood maps of the fabricated detectors exposed to 122 keV gammas, peak-to-valley (P/V) ratios of greater than 2.3 are calculated. The P/V values suggest that regardless of the crystal thickness, the pixels can be resolved. Conclusions: The results suggest that optical barriers can be considered as a robust alternative to mechanically pixelated arrays and can provide high spatial resolution while maintaining the sensitivity in a high-throughput and cost-effective manner. PMID:27147372

Array servo scanning micro EDM of 3D micro cavities

NASA Astrophysics Data System (ADS)

Tong, Hao; Li, Yong; Yi, Futing

2011-05-01

Micro electro discharge machining (Micro EDM) is a non-traditional processing technology with the special advantages of low set-up cost and few cutting force in machining any conductive materials regardless of their hardness. As well known, die-sinking EDM is unsuitable for machining the complex 3D micro cavity less than 1mm due to the high-priced fabrication of 3D microelectrode itself and its serous wear during EDM process. In our former study, a servo scanning 3D micro-EDM (3D SSMEDM) method was put forward, and our experiments showed it was available to fabricate complex 3D micro-cavities. In this study, in order to improve machining efficiency and consistency accuracy for array 3D micro-cavities, an array-servo-scanning 3D micro EDM (3D ASSMEDM) method is presented considering the complementary advantages of the 3D SSMEDM and the array micro electrodes with simple cross-section. During 3D ASSMEDM process, the array cavities designed by CAD / CAM system can be batch-manufactured by servo scanning layer by layer using array-rod-like micro tool electrodes, and the axial wear of the array electrodes is compensated in real time by keeping discharge gap. To verify the effectiveness of the 3D ASSMEDM, the array-triangle-micro cavities (side length 630 μm) are batch-manufactured on P-doped silicon by applying the array-micro-electrodes with square-cross-section fabricated by LIGA process. Our exploratory experiment shows that the 3D ASSMEDM provides a feasible approach for the batch-manufacture of 3D array-micro-cavities of conductive materials.

An “ohmic-first” self-terminating gate-recess technique for normally-off Al2O3/GaN MOSFET

NASA Astrophysics Data System (ADS)

Wang, Hongyue; Wang, Jinyan; Li, Mengjun; He, Yandong; Wang, Maojun; Yu, Min; Wu, Wengang; Zhou, Yang; Dai, Gang

2018-04-01

In this article, an ohmic-first AlGaN/GaN self-terminating gate-recess etching technique was demonstrated where ohmic contact formation is ahead of gate-recess-etching/gate-dielectric-deposition (GRE/GDD) process. The ohmic contact exhibits few degradations after the self-terminating gate-recess process. Besides, when comparing with that using the conventional fabrication process, the fabricated device using the ohmic-first fabrication process shows a better gate dielectric quality in terms of more than 3 orders lower forward gate leakage current, more than twice higher reverse breakdown voltage as well as better stability. Based on this proposed technique, the normally-off Al2O3/GaN MOSFET exhibits a threshold voltage (V th) of ˜1.8 V, a maximum drain current of ˜328 mA/mm, a forward gate leakage current of ˜10-6 A/mm and an off-state breakdown voltage of 218 V at room temperature. Meanwhile, high temperature characteristics of the device was also evaluated and small variations (˜7.6%) of the threshold voltage was confirmed up to 300 °C.

Nanocrystal floating gate memory with solution-processed indium-zinc-tin-oxide channel and colloidal silver nanocrystals

NASA Astrophysics Data System (ADS)

Hu, Quanli; Ha, Sang-Hyub; Lee, Hyun Ho; Yoon, Tae-Sik

2011-12-01

A nanocrystal (NC) floating gate memory with solution-processed indium-zinc-tin-oxide (IZTO) channel and silver (Ag) NCs embedded in thin gate dielectric layer (SiO2(30 nm)/Al2O3(3 nm)) was fabricated. Both the IZTO channel and colloidal Ag NC layers were prepared by spin-coating and subsequent annealing, and dip-coating process, respectively. A threshold voltage shift up to ~0.9 V, corresponding to the electron density of 6.5 × 1011 cm-2, at gate pulsing <=10 V was achieved by the charging of high density NCs. These results present the successful non-volatile memory characteristics of an oxide-semiconductor transistor fabricated through solution processes.

Three-Dimensional Integrated Circuit (3D IC) Key Technology: Through-Silicon Via (TSV).

PubMed

Shen, Wen-Wei; Chen, Kuan-Neng

2017-12-01

3D integration with through-silicon via (TSV) is a promising candidate to perform system-level integration with smaller package size, higher interconnection density, and better performance. TSV fabrication is the key technology to permit communications between various strata of the 3D integration system. TSV fabrication steps, such as etching, isolation, metallization processes, and related failure modes, as well as other characterizations are discussed in this invited review paper.

Prototype Space Fabrication Platform

DTIC Science & Technology

1993-12-01

Wheel Mechanism . . 5-12 5.3.4 Butt Welding of T-Beams ..... .......... 5-14 5.3.5 Application of Cross Members ............ 5-17 5.3.6 Application of...fabrication process and deployed into spece by a drive mechanism on each cap member. The drive mechanism also provided the force necessary to extract...members were stacked closely together and stored in a clip mechanism . The clip had a belt ’ ed mechanism designed to advance the stack, one member at

On the intrinsic sterility of 3D printing

PubMed Central

Flynn, Kaitlin J.; Zaman, Luis; Tung, Emily; Pudlo, Nicholas

2016-01-01

3D printers that build objects using extruded thermoplastic are quickly becoming commonplace tools in laboratories. We demonstrate that with appropriate handling, these devices are capable of producing sterile components from a non-sterile feedstock of thermoplastic without any treatment after fabrication. The fabrication process itself results in sterilization of the material. The resulting 3D printed components are suitable for a wide variety of applications, including experiments with bacteria and cell culture. PMID:27920950

Fabrication of superhydrophobic Pt3Fe/Fe surface for its application

NASA Astrophysics Data System (ADS)

Cui, Shuo; Lu, Shixiang; Xu, Wenguo; Wu, Bei

2017-10-01

Well-defined Pt3Fe/Fe superhydrophobic materials on iron sheet with special properties, such as corrosion resistance, superhydrophobicity and superoleophilicity, was fabricated. The fabrication process involved etching in hydrochloric acid aqueous solution and simple replacement deposition process without using any seed and organic solvent, and then annealing. The electrochemical measurements show that the resultant surface in 3.5% sodium chloride solution displays good corrosion resistance. Also, it is proved that the obtained surface has better mechanical abrasion resistance via scratch test. The superoleophilicity and low water adhesion force of the obtained surface endow it high oil/water separation capacity. The as-prepared nanocomposites display enhanced catalytic activity and kinetics toward degradation of methyl orange. In particular, it possesses the most efficient degradation capacity (95%) towards methyl orange at a high concentration (17.5 mg/L) in 80 min. The improved stability and excellent catalytic activity of the Pt3Fe/Fe nanocomposites promise new opportunities for the development of waste water treatment.

Energy efficient engine high pressure turbine ceramic shroud support technology report

NASA Technical Reports Server (NTRS)

Nelson, W. A.; Carlson, R. G.

1982-01-01

This work represents the development and fabrication of ceramic HPT (high pressure turbine) shrouds for the Energy Efficient Engine (E3). Details are presented covering the work performed on the ceramic shroud development task of the NASA/GE Energy Efficient Engine (E3) component development program. The task consists of four phases which led to the selection of a ZrO2-BY2O3 ceramic shroud material system, the development of an automated plasma spray process to produce acceptable shroud structures, the fabrication of select shroud systems for evaluation in laboratory, component, and CF6-50 engine testing, and finally, the successful fabrication of ZrO2-8Y2O3/superpeg, engine quality shrouds for the E3 engine.

Electrospinning Fabrication of SrTiO3 Nanofibers and Their Photocatalytic Activity

NASA Astrophysics Data System (ADS)

Xu, Lei; Zhao, Yiping; Wang, Wei; Liu, Hao; Wang, Rui

2018-06-01

SrTiO3 nanofibers were fabricated by an electrospinning process. The phase, microstructure and photocatalytic activity of the obtained SrTiO3 nanofibers were investigated. The XRD patterns and the SEM images suggest that SrTiO3 nanofibers with perovskite phase and rough surface have been fabricated in the current work. The SrTiO3 nanofibers show a high efficiency decomposition of RhB under ultraviolet light irradiation. The high photocatalytic activity of SrTiO3 nanofibers results from the large specific surface area. The large specific surface area provides more surface active sits and makes an easier charge carrier transport. On the basis of the photocatalytic performance of SrTiO3 nanofibers, the possible photocatalysis mechanism was proposed.

Evaluation of shielding parameters for heavy metal fluoride based tellurite-rich glasses for gamma ray shielding applications

NASA Astrophysics Data System (ADS)

Sayyed, M. I.; Lakshminarayana, G.; Kityk, I. V.; Mahdi, M. A.

2017-10-01

In this work, we have evaluated the γ-ray shielding parameters such as mass attenuation coefficient (μ/ρ), effective atomic number (Zeff), half value layer (HVL), mean free path (MFP) and exposure buildup factors (EBF) for heavy metal fluoride (PbF2) based tellurite-rich glasses. In addition, neutron total macroscopic cross sections (∑R) for these glasses were also calculated. The maximum value for μ/ρ, Zeff and ∑R was found for heavy metal (Bi2O3) oxide introduced glass. The results of the selected glasses have been compared, in terms of MFP with different glass systems. The shielding effectiveness of the selected glasses is found comparable or better than of common ones, which indicates that these glasses with suitable oxides could be developed for gamma ray shielding applications.

Manufacturing of polymer optical waveguides using self-assembly effect on pre-conditioned 3D-thermoformed flexible substrates

NASA Astrophysics Data System (ADS)

Hoffmann, Gerd-Albert; Wolfer, Tim; Zeitler, Jochen; Franke, Jörg; Suttmann, Oliver; Overmeyer, Ludger

2017-02-01

Optical data communication is increasingly interesting for many applications in industrial processes. Therefore mass production is required to meet the requested price and lot sizes. Polymer optical waveguides show great promises to comply with price requirements while providing sufficient optical quality for short range data transmission. A high efficient fabrication technology using polymer materials could be able to create the essential backbone for 3D-optical data transmission in the future. The approach for high efficient fabrication technology of micro optics described in this paper is based on a self-assembly effect of fluids on preconditioned 3D-thermoformed polymer foils. Adjusting the surface energy on certain areas on the flexible substrate by flexographic printing mechanism is presented in this paper. With this technique conditioning lines made of silicone containing UV-varnish are printed on top of the foils and create gaps with the exposed substrate material in between. Subsequent fabrication processes are selected whether the preconditioned foil is coated with acrylate containing waveguide material prior or after the thermoforming process. Due to the different surface energy this material tends to dewet from the conditioning lines. It acts like regional barriers and sets the width of the arising waveguides. With this fabrication technology it is possible to produce multiple waveguides with a single coating process. The relevant printing process parameters that affect the quality of the generated waveguides are discussed and results of the produced waveguides with width ranging from 10 to 300 μm are shown.

Flexible ITO-free organic solar cells applying aqueous solution-processed V2O5 hole transport layer: An outdoor stability study

NASA Astrophysics Data System (ADS)

Lima, F. Anderson S.; Beliatis, Michail J.; Roth, Bérenger; Andersen, Thomas R.; Bortoti, Andressa; Reyna, Yegraf; Castro, Eryza; Vasconcelos, Igor F.; Gevorgyan, Suren A.; Krebs, Frederik C.; Lira-Cantu, Mónica

2016-02-01

Solution processable semiconductor oxides have opened a new paradigm for the enhancement of the lifetime of thin film solar cells. Their fabrication by low-cost and environmentally friendly solution-processable methods makes them ideal barrier (hole and electron) transport layers. In this work, we fabricate flexible ITO-free organic solar cells (OPV) by printing methods applying an aqueous solution-processed V2O5 as the hole transport layer (HTL) and compared them to devices applying PEDOT:PSS. The transparent conducting electrode was PET/Ag/PEDOT/ZnO, and the OPV configuration was PET/Ag/PEDOT/ZnO/P3HT:PC60BM/HTL/Ag. Outdoor stability analyses carried out for more than 900 h revealed higher stability for devices fabricated with the aqueous solution-processed V2O5.

Sandia Advanced MEMS Design Tools v. 3.0

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yarberry, Victor R.; Allen, James J.; Lantz, Jeffrey W.

This is a major revision to the Sandia Advanced MEMS Design Tools. It replaces all previous versions. New features in this version: Revised to support AutoCAD 2014 and 2015 This CD contains an integrated set of electronic files that: a) Describe the SUMMiT V fabrication process b) Provide enabling educational information (including pictures, videos, technical information) c) Facilitate the process of designing MEMS with the SUMMiT process (prototype file, Design Rule Checker, Standard Parts Library) d) Facilitate the process of having MEMS fabricated at Sandia National Laboratories e) Facilitate the process of having post-fabrication services performed. While there exists somemore » files on the CD that are used in conjunction with software package AutoCAD, these files are not intended for use independent of the CD. Note that the customer must purchase his/her own copy of AutoCAD to use with these files.« less

Detailed study of scratch drive actuator characteristics using high-speed imaging

NASA Astrophysics Data System (ADS)

Li, Lijie; Brown, James G.; Uttamchandani, Deepak G.

2001-10-01

Microactuators are one of the key components in MEMS and Microsystems technology, and various designs have been realized through different fabrication processes. One type of microactuator commonly used is the scratch drive actuator (SDA) that is frequently fabricated by surface micromachining processes. An experimental investigation has been conducted on the characteristics of SDAs fabricated using the Cronos Microsystems MUMPs process. The motivation is to compare the response of SDAs located on the same die, and SDAs located on the different dies from the same fabrication batch. A high-speed imaging camera has been used to precisely determine important SDA characteristics such as step size, velocity, maximum velocity, and acceleration over long travel distance. These measurements are important from a repeatability point of view, and in order to fully exploit the potential of the SDA as a precise positioning mechanism. 2- and 3-stage SDAs have been designed and fabricated for these experiments. Typical step sizes varying from 7 nm at a driving voltage of 60 V to 23 nm at 290 V have been obtained.

Nutritional status, exclusive breastfeeding and management of acute respiratory illness and diarrhea in the first 6 months of life in infants from two regions of Indonesia.

PubMed

Oktaria, V; Lee, K J; Bines, J E; Watts, E; Satria, C D; Atthobari, J; Nirwati, H; Kirkwood, C D; Soenarto, Y; Danchin, M H

2017-12-21

Infant morbidity and mortality rates remain high in Indonesia, with acute respiratory illnesses (ARI) and diarrhea the leading two health problems in children under 5 years. We aimed to describe the nutritional status, feeding practice and case management of ARI and diarrhea of infants from two regions of Indonesia during the first 6 months of life. This study was an observational study conducted in parallel to an immunogenicity and efficacy trial of an oral rotavirus vaccine (RV3-BB) in the Klaten and Yogyakarta regions, Indonesia. Mothers were interviewed at 3 time points: within the first 6 days of their infant's life, and at 8-10 and 22-24 weeks of age. Questions asked included pregnancy history, infant nutritional status, feeding status and health of infants within up to 2 weeks prior to the assessment. Between February 2013 and January 2014, 233 mother-infant pairs were recruited. 60% (136/223) of infants were exclusively breastfed (EBF) until 6 months of age with the strongest support for EBF reported by mothers themselves 70% (101/223) and 25% (36/223) from their partners. At 6 months, 6% (14/223) of infants were underweight and severely underweight; 4% (8/ 223) wasted and severely wasted; and 12% (28/223) were stunted and severely stunted. Non-recommended medication use was high, with 54% (21/39) of infants with reported cough within 2 weeks of an assessment receiving cough medication, 70% (27 /39) an antihistamine, 26% (10/39) a mucolytic and 15% (6 /39) an oral bronchodilator. At age 22-24 week, infants with reported diarrhea within 2 weeks of an assessment had low use of oral rehydration solutions (ORS) (3/21;14%) and zinc therapy (2/ 21;10%). In this unique observational study, breastfeeding rates of 60% at 6 months were below the Indonesian national target of >75%. Adherence to WHO guidelines for management of ARI and diarrhea was poor, with high use of non-recommended cough medications and oral bronchodilators in the first 6 months of life and low use of ORS and zinc therapy. Ongoing education of primary health care workers and parents regarding management of common illness is needed in Indonesia.

Tribology of Polymer Matrix Composites (PMCs) Fabricated by Additive Manufacturing (AM)

NASA Technical Reports Server (NTRS)

Gupta, S.; Dunnigan, R.; Salem, A.; Kuentz, L.; Halbig, M. C.; Singh, M.

2016-01-01

The integral process of depositing thin layers of material, one after another, until the designed component is created is collectively referred to as Additive Manufacturing (AM). Fused deposition process (FDP) is a type of AM where feedstock is extruded into filaments which then are deposited by 3D printing, and the solidification occurs during cooling of the melt. Currently, complex structures are being fabricated by commercial and open source desktop 3D printers. Recently, metal powder containing composite filaments based on polylactic acid (PLA) and acrylonitrile butadiene styrene (ABS) have emerged, which could be utilized for multifunctional applications. For further deployment in the field, especially for aerospace and ground-based applications, it is critical to understand the tribological behavior of 3D printed materials. In this presentation, we will report the tribological behavior of different polymer matrix composites fabricated by fused deposition process. These results will be compared with the base polymer systems. During this study, the tribological behavior of all the samples will be evaluated with tab-on-disc method and compared for different metallic powder reinforcements.

Self-assembly of silica nanoparticles into hollow spheres via a microwave-assisted aerosol process

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Shan; Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology, Changzhou University, Changzhou 213164; Wang, Fei

2016-02-15

Highlights: • The silica hollow spheres were fabricated via a microwave-assisted aerosol process. • The formation of the hollow spheres was obtained through a one-step process. • The spheres indicated the remarkable sustained release of potassium persulfate. - Abstract: In this work, a simple and efficient strategy for fabrication of silica hollow spheres (SHSs) has been successfully introduced with a one-step microwave-assisted aerosol process using silica nanoparticles (SiO{sub 2}, 12–50 nm) and NH{sub 4}HCO{sub 3} as precursor materials. This approach combines the merits of microwave radiation and the aerosol technique. And the formation of SHSs is ascribed to solvent evaporationmore » and the as-generated gas from NH{sub 4}HCO{sub 3} decomposition in the microwave reactor. The morphology of the SHSs can be easily tuned by varying the residence time, amount of NH{sub 4}HCO{sub 3} and silica sources. The formation mechanism of SHSs was also investigated by structure analysis. In addition, the hollow spheres exhibited remarkable sustained release of potassium persulfate, by loading it into the porous structures. The results provide new sights into the fabrication of inorganic hollow spheres via a one-step process.« less

In Situ Fabrication Technologies: Meeting the Challenge for Exploration

NASA Technical Reports Server (NTRS)

Howard, Richard W.

2005-01-01

A viewgraph presentation on Lunar and Martian in situ fabrication technologies meeting the challenges for exploration is shown. The topics include: 1) Exploration Vision; 2) Vision Requirements Early in the Program; 3) Vision Requirements Today; 4) Why is ISFR Technology Needed? 5) ISFR and In Situ Resource Utilization (ISRU); 6) Fabrication Feedstock Considerations; 7) Planetary Resource Primer; 8) Average Chemical Element Abundances in Lunar Soil; 9) Chemical Elements in Aerospace Engineering Materials; 10) Schematic of Raw Regolith Processing into Constituent Components; 11) Iron, Aluminum, and Basalt Processing from Separated Elements and Compounds; 12) Space Power Systems; 13) Power Source Applicability; 14) Fabrication Systems Technologies; 15) Repair and Nondestructive Evaluation (NDE); and 16) Habitat Structures. A development overview of Lunar and Martian repair and nondestructive evaluation is also presented.

Statistical Analysis of Firearms/Toolmarks Interpretation of Cartridge Case Evidence Using IBIS and Bayesian Networks

DTIC Science & Technology

2015-10-24

reference material (SRM) was entered into IBIS 10 times by each of three users (EBF, RLJ, and EFL). Each of these users has more than 12 months...bullet leaves the muzzle. In a recoil action (locked breech) pistol, the barrel and slide are securely locked together at the moment of firing. They...travel backward together until the barrel unlocks, forced down by a link or inclined plane, and continues rearward under its own momentum. A

The fabrication of carbon nanotube field-effect transistors with semiconductors as the source and drain contact materials.

PubMed

Xiao, Z; Camino, F E

2009-04-01

Sb(2)Te(3) and Bi(2)Te(2)Se semiconductor materials were used as the source and drain contact materials in the fabrication of carbon nanotube field-effect transistors (CNTFETs). Ultra-purified single-walled carbon nanotubes (SWCNTs) were ultrasonically dispersed in N-methyl pyrrolidone solvent. Dielectrophoresis was used to deposit and align SWCNTs for fabrication of CNTFETs. The Sb(2)Te(3)- and Bi(2)Te(2)Se-based CNTFETs demonstrate p-type metal-oxide-silicon-like I-V curves with high on/off drain-source current ratio at large drain-source voltages and good saturation of drain-source current with increasing drain-source voltage. The fabrication process developed is novel and has general meaning, and could be used for the fabrication of SWCNT-based integrated devices and systems with semiconductor contact materials.

Controllable 3D architectures of aligned carbon nanotube arrays by multi-step processes

NASA Astrophysics Data System (ADS)

Huang, Shaoming

2003-06-01

An effective way to fabricate large area three-dimensional (3D) aligned CNTs pattern based on pyrolysis of iron(II) phthalocyanine (FePc) by two-step processes is reported. The controllable generation of different lengths and selective growth of the aligned CNT arrays on metal-patterned (e.g., Ag and Au) substrate are the bases for generating such 3D aligned CNTs architectures. By controlling experimental conditions 3D aligned CNT arrays with different lengths/densities and morphologies/structures as well as multi-layered architectures can be fabricated in large scale by multi-step pyrolysis of FePc. These 3D architectures could have interesting properties and be applied for developing novel nanotube-based devices.

Large-scale fabrication of porous YBO3 hollow microspheres with tunable photoluminescence

NASA Astrophysics Data System (ADS)

Xu, Zhenhe; Yu, He; Ai, Feixue; Zhao, Guiyan; Bi, Yanfeng; Huang, Liangliang; Ding, Fu; Sun, Yaguang; Gao, Yu

2018-04-01

Hollow lanthanide-doped compounds are some of the most popular materials for high-performance luminescent devices. However, it is challenging to find an approach that can fabricate large-scale and well-crystallized lanthanide-doped hollow structures and that is facile, efficient and of low cost. In this study, YBO3: Eu3+/Tb3+ hollow microspheres were fabricated by using a novel multi-step transformation synthetic route for the first time with polystyrene spheres as the template, followed by the combination of a facile homogeneous precipitation method, an ion-exchange process and a calcination process. The results show that the as-obtained YBO3: Eu3+/Tb3+ hollow spheres have a uniform morphology with an average diameter of 1.65 µm and shell thickness of about 160 nm. When used as luminescent materials, the emission colours of YBO3: Eu3+/Tb3+ samples can be tuned from red, through orange, yellow and green-yellow, to green by simply adjusting the relative doping concentrations of the activator ions under the excitation of ultraviolet light, which might have potential applications in fields such as light display systems and optoelectronic devices.

Multiscale 3D manufacturing: combining thermal extrusion printing with additive and subtractive direct laser writing

NASA Astrophysics Data System (ADS)

Malinauskas, Mangirdas; Lukoševičius, Laurynas; MackevičiÅ«tÄ--, DovilÄ--; BalčiÅ«nas, Evaldas; RekštytÄ--, Sima; Paipulas, Domas

2014-05-01

A novel approach for efficient manufacturing of three-dimensional (3D) microstructured scaffolds designed for cell studies and tissue engineering applications is presented. A thermal extrusion (fused filament fabrication) 3D printer is employed as a simple and low-cost tabletop device enabling rapid materialization of CAD models out of biocompatible and biodegradable polylactic acid (PLA). Here it was used to produce cm- scale microporous (pore size varying from 100 to 400 µm) scaffolds. The fabricated objects were further laser processed in a direct laser writing (DLW) subtractive (ablation) and additive (lithography) manners. The first approach enables precise surface modification by creating micro-craters, holes and grooves thus increasing the surface roughness. An alternative way is to immerse the 3D PLA scaffold in a monomer solution and use the same DLW setup to refine its inner structure by fabricating dots, lines or a fine mesh on top as well as inside the pores of previously produced scaffolds. The DLW technique is empowered by ultrafast lasers - it allows 3D structuring with high spatial resolution in a great variety of photosensitive materials. Structure geometry on macro- to micro- scales could be finely tuned by combining these two fabrication techniques. Such artificial 3D substrates could be used for cell growth or as biocompatible-biodegradable implants. This combination of distinct material processing techniques enables rapid fabrication of diverse functional micro- featured and integrated devices. Hopefully, the proposed approach will find numerous applications in the field of ms, microfluidics, microoptics and many others.

Development of a new generation of high-temperature composite materials

NASA Technical Reports Server (NTRS)

Brindley, P. K.

1990-01-01

Intermetallic matrix composites proposed to meet advanced aeropropulsion requirements are discussed. The powder metallurgy fabrication process currently being used to produce these intermetallic matrix composites will be presented, as will properties of one such composite, SiC/Ti3Al+Nb. In addition, the direction of future research will be outlined, including plans for enhanced fabrication of intermetallic composites by the arc-spray technique and fiber development by the floating-zone process.

Additive manufacturing of three-dimensional (3D) microfluidic-based microelectromechanical systems (MEMS) for acoustofluidic applications.

PubMed

Cesewski, Ellen; Haring, Alexander P; Tong, Yuxin; Singh, Manjot; Thakur, Rajan; Laheri, Sahil; Read, Kaitlin A; Powell, Michael D; Oestreich, Kenneth J; Johnson, Blake N

2018-06-13

Three-dimensional (3D) printing now enables the fabrication of 3D structural electronics and microfluidics. Further, conventional subtractive manufacturing processes for microelectromechanical systems (MEMS) relatively limit device structure to two dimensions and require post-processing steps for interface with microfluidics. Thus, the objective of this work is to create an additive manufacturing approach for fabrication of 3D microfluidic-based MEMS devices that enables 3D configurations of electromechanical systems and simultaneous integration of microfluidics. Here, we demonstrate the ability to fabricate microfluidic-based acoustofluidic devices that contain orthogonal out-of-plane piezoelectric sensors and actuators using additive manufacturing. The devices were fabricated using a microextrusion 3D printing system that contained integrated pick-and-place functionality. Additively assembled materials and components included 3D printed epoxy, polydimethylsiloxane (PDMS), silver nanoparticles, and eutectic gallium-indium as well as robotically embedded piezoelectric chips (lead zirconate titanate (PZT)). Electrical impedance spectroscopy and finite element modeling studies showed the embedded PZT chips exhibited multiple resonant modes of varying mode shape over the 0-20 MHz frequency range. Flow visualization studies using neutrally buoyant particles (diameter = 0.8-70 μm) confirmed the 3D printed devices generated bulk acoustic waves (BAWs) capable of size-selective manipulation, trapping, and separation of suspended particles in droplets and microchannels. Flow visualization studies in a continuous flow format showed suspended particles could be moved toward or away from the walls of microfluidic channels based on selective actuation of in-plane or out-of-plane PZT chips. This work suggests additive manufacturing potentially provides new opportunities for the design and fabrication of acoustofluidic and microfluidic devices.

1km Global Terrestrial Carbon Flux: Estimations and Evaluations

NASA Astrophysics Data System (ADS)

Murakami, K.; Sasai, T.; Kato, S.; Saito, M.; Matsunaga, T.; Hiraki, K.; Maksyutov, S. S.

2017-12-01

Estimating global scale of the terrestrial carbon flux change with high accuracy and high resolution is important to understand global environmental changes. Furthermore the estimations of the global spatiotemporal distribution may contribute to the political and social activities such as REDD+. In order to reveal the current state of terrestrial carbon fluxes covering all over the world and a decadal scale. The satellite-based diagnostic biosphere model is suitable for achieving this purpose owing to observing on the present global land surface condition uniformly at some time interval. In this study, we estimated the global terrestrial carbon fluxes with 1km grids by using the terrestrial biosphere model (BEAMS). And we evaluated our new carbon flux estimations on various spatial scales and showed the transition of forest carbon stocks in some regions. Because BEAMS required high resolution meteorological data and satellite data as input data, we made 1km interpolated data using a kriging method. The data used in this study were JRA-55, GPCP, GOSAT L4B atmospheric CO2 data as meteorological data, and MODIS land product as land surface satellite data. Interpolating process was performed on the meteorological data because of insufficient resolution, but not on MODIS data. We evaluated our new carbon flux estimations using the flux tower measurement (FLUXNET2015 Datasets) in a point scale. We used 166 sites data for evaluating our model results. These flux sites are classified following vegetation type (DBF, EBF, ENF, mixed forests, grass lands, croplands, shrub lands, Savannas, wetlands). In global scale, the BEAMS estimations was underestimated compared to the flux measurements in the case of carbon uptake and release. The monthly variations of NEP showed relatively high correlations in DBF and mixed forests, but the correlation coefficients of EBF, ENF, and grass lands were less than 0.5. In the meteorological factors, air temperature and solar radiation showed very high correlations, and slight variations were showed in precipitation data. LAI data that was another large driving factor of terrestrial carbon cycle was not included in FLUXNET2015 datasets and it could not be evaluated.

Fabrication of Ce3+ doped Gd3Ga3Al2O12 ceramics by reactive sintering method

NASA Astrophysics Data System (ADS)

Ye, Yong; Liu, Peng; Yan, Dongyue; Xu, Xiaodong; Zhang, Jian

2017-09-01

Ce3+ doped Gd3Ga3Al2O12 (Ce:GGAG) ceramics were fabricated by solid state reactive sintering method in this study. The ceramics were pre-sintered in normal muffle furnace in air at various temperature range from 1410 °C to 1550 °C for 10 h and post-treated by hot isostatic press at 1400 °C/2 h in 200 MPa Ar. The phase and microstructure evolution of Ce: GGAG samples during the densification process were investigated by X-ray diffraction and scanning electron microscope. Pure GGAG phase appeared with the temperature increased to 1200 °C. The fully dense and translucent GGAG ceramics were fabricated by pre-sintering at 1450 °C and followed by HIP treatment.

Thermal Skin fabrication technology

NASA Technical Reports Server (NTRS)

Milam, T. B.

1972-01-01

Advanced fabrication techniques applicable to Thermal Skin structures were investigated, including: (1) chemical machining; (2) braze bonding; (3) diffusion bonding; and (4) electron beam welding. Materials investigated were nickel and nickel alloys. Sample Thermal Skin panels were manufactured using the advanced fabrication techniques studied and were structurally tested. Results of the program included: (1) development of improved chemical machining processes for nickel and several nickel alloys; (2) identification of design geometry limits; (3) identification of diffusion bonding requirements; (4) development of a unique diffusion bonding tool; (5) identification of electron beam welding limits; and (6) identification of structural properties of Thermal Skin material.

In Situ Thermal Generation of Silver Nanoparticles in 3D Printed Polymeric Structures.

PubMed

Fantino, Erika; Chiappone, Annalisa; Calignano, Flaviana; Fontana, Marco; Pirri, Fabrizio; Roppolo, Ignazio

2016-07-19

Polymer nanocomposites have always attracted the interest of researchers and industry because of their potential combination of properties from both the nanofillers and the hosting matrix. Gathering nanomaterials and 3D printing could offer clear advantages and numerous new opportunities in several application fields. Embedding nanofillers in a polymeric matrix could improve the final material properties but usually the printing process gets more difficult. Considering this drawback, in this paper we propose a method to obtain polymer nanocomposites by in situ generation of nanoparticles after the printing process. 3D structures were fabricated through a Digital Light Processing (DLP) system by disolving metal salts in the starting liquid formulation. The 3D fabrication is followed by a thermal treatment in order to induce in situ generation of metal nanoparticles (NPs) in the polymer matrix. Comprehensive studies were systematically performed on the thermo-mechanical characteristics, morphology and electrical properties of the 3D printed nanocomposites.

Fabrication of seamless calandria tubes by cold pilgering route using 3-pass and 2-pass schedules

NASA Astrophysics Data System (ADS)

Saibaba, N.

2008-12-01

Calandria tube is a large diameter, extremely thin walled zirconium alloy tube which has diameter to wall thickness ratio as high as 90-95. Such tubes are conventionally produced by the 'welded route', which involves extrusion of slabs followed by a series of hot and cold rolling passes, intermediate anneals, press forming of sheets into circular shape and closing the gap by TIG welding. Though pilgering is a well established process for the fabrication of seamless tubes, production of extremely thin walled tubes offers several challenges during pilgering. Nuclear fuel complex (NFC), Hyderabad, has successfully developed a process for the production of Zircaloy-4 calandria tubes by adopting the 'seamless route' which involves hot extrusion of mother blanks followed by three-pass pilgering or two-pass pilgering schedules. This paper deals with standardization of the seamless route processes for fabrication of calandria tubes, comparison between the tubes produced by 2-pass and 3-pass pilgering schedules, role of ultrasonic test charts for control of process parameters, development of new testing methods for burst testing and other properties.

Manufacture of bulk superconducting YBa2Cu3O(7-delta) by a continuous process

NASA Technical Reports Server (NTRS)

Meng, R. L.; Kinalidis, C.; Sun, Y. Y.; Gao, L.; Tao, Y. K.

1990-01-01

The development of a continuous process for fabricating large bulk superconductors with a predetermined grain orientation is reported. A bar of the 123 compound with dimensions 5 x 0.5 x about 0.3 cm with excellent grain alignment has been fabricated continuously. The bulk 123 thus obtained has magnetically determined J(c)s of about 30,000 and 12,000 A/sq cm at 0 and 1 T, respectively, and transport J(c)s of 20,000, 11,000, and 7500 A-sq cm at 0, 0.54, and 0.83 T.

Electrothermally-Actuated Micromirrors with Bimorph Actuators—Bending-Type and Torsion-Type

PubMed Central

Tsai, Cheng-Hua; Tsai, Chun-Wei; Chang, Hsu-Tang; Liu, Shih-Hsiang; Tsai, Jui-Che

2015-01-01

Three different electrothermally-actuated MEMS micromirrors with Cr/Au-Si bimorph actuators are proposed. The devices are fabricated with the SOIMUMPs process developed by MEMSCAP, Inc. (Durham, NC, USA). A silicon-on-insulator MEMS process has been employed for the fabrication of these micromirrors. Electrothermal actuation has achieved a large angular movement in the micromirrors. Application of an external electric current 0.04 A to the bending-type, restricted-torsion-type, and free-torsion-type mirrors achieved rotation angles of 1.69°, 3.28°, and 3.64°, respectively. PMID:26110409

Fabrication of self-aligned, nanoscale, complex oxide varactors

NASA Astrophysics Data System (ADS)

Fu, Richard X.; Toonen, Ryan C.; Hirsch, Samuel G.; Ivill, Mathew P.; Cole, Melanie W.; Strawhecker, Kenneth E.

2015-01-01

Applications in ferroelectric random access memory and superparaelectric devices require the fabrication of ferroelectric capacitors at the nanoscale that exhibit extremely small leakage currents. To systematically study the material-size dependence of ferroelectric varactor performance, arrays of parallel-plate structures have been fabricated with nanoscale dielectric diameters. Electron beam lithography and inductively coupled plasma dry etching have been used to fabricate arrays of ferroelectric varactors using top electrodes as a self-aligned etch mask. Parallel-plate test structures using RF-sputtered Ba0.6Sr0.4TiO3 thin-films were used to optimize the fabrication process. Varactors with diameters down to 20 nm were successfully fabricated. Current-voltage (I-V) characteristics were measured to evaluate the significance of etch-damage and fabrication quality by ensuring low leakage currents through the structures.

Direct ink write fabrication of transparent ceramic gain media

NASA Astrophysics Data System (ADS)

Jones, Ivy Krystal; Seeley, Zachary M.; Cherepy, Nerine J.; Duoss, Eric B.; Payne, Stephen A.

2018-01-01

Solid-state laser gain media based on the garnet structure with two spatially distinct but optically contiguous regions have been fabricated. Transparent gain media comprised of a central core of Y2.97Nd0.03Al5.00O12.00 (Nd:YAG) and an undoped cladding region of Y3Al5O12 (YAG) were fabricated by direct ink write and transparent ceramic processing. Direct ink write (DIW) was employed to form the green body, offering a general route to preparing functionally structured solid-state laser gain media. Fully-dense transparent optical ceramics in a "top hat" geometry with YAG/Nd:YAG have been fabricated by DIW methods with optical scatter at 1064 nm of <3%/cm.

Benchtop fabrication of three-dimensional reconfigurable microfluidic devices from paper-polymer composite.

PubMed

Han, Yu Long; Wang, Wenqi; Hu, Jie; Huang, Guoyou; Wang, Shuqi; Lee, Won Gu; Lu, Tian Jian; Xu, Feng

2013-12-21

We presented a benchtop technique that can fabricate reconfigurable, three-dimensional (3D) microfluidic devices made from a soft paper-polymer composite. This fabrication approach can produce microchannels at a minimal width of 100 μm and can be used to prototype 3D microfluidic devices by simple bending and stretching. The entire fabrication process can be finished in 2 hours on a laboratory bench without the need for special equipment involved in lithography. Various functional microfluidic devices (e.g., droplet generator and reconfigurable electronic circuit) were prepared using this paper-polymer hybrid microfluidic system. The developed method can be applied in a wide range of standard applications and emerging technologies such as liquid-phase electronics.

Rare-Earth Oxide (Yb2O3) Selective Emitter Fabrication and Evaluation

NASA Technical Reports Server (NTRS)

Jennette, Bryan; Gregory, Don A.; Herren, Kenneth; Tucker, Dennis; Smith, W. Scott (Technical Monitor)

2001-01-01

This investigation involved the fabrication and evaluation of rare-earth oxide selective emitters. The first goal of this study was to successfully fabricate the selective emitter samples using paper and ceramic materials processing techniques. The resulting microstructure was also analyzed using a Scanning Electron Microscope. All selective emitter samples fabricated for this study were made with ytterbium oxide (Yb2O3). The second goal of this study involved the measurement of the spectral emission and the radiated power of all the selective emitter samples. The final goal of this study involved the direct comparison of the radiated power emitted by the selective emitter samples to that of a standard blackbody at the same temperature and within the same wavelength range.

Adiabatic tapered optical fiber fabrication in two step etching

NASA Astrophysics Data System (ADS)

Chenari, Z.; Latifi, H.; Ghamari, S.; Hashemi, R. S.; Doroodmand, F.

2016-01-01

A two-step etching method using HF acid and Buffered HF is proposed to fabricate adiabatic biconical optical fiber tapers. Due to the fact that the etching rate in second step is almost 3 times slower than the previous droplet etching method, terminating the fabrication process is controllable enough to achieve a desirable fiber diameter. By monitoring transmitted spectrum, final diameter and adiabaticity of tapers are deduced. Tapers with losses about 0.3 dB in air and 4.2 dB in water are produced. The biconical fiber taper fabricated using this method is used to excite whispering gallery modes (WGMs) on a microsphere surface in an aquatic environment. So that they are suitable to be used in applications like WGM biosensors.

Applying macromolecular crowding to 3D bioprinting: fabrication of 3D hierarchical porous collagen-based hydrogel constructs.

PubMed

Ng, Wei Long; Goh, Min Hao; Yeong, Wai Yee; Naing, May Win

2018-02-27

Native tissues and/or organs possess complex hierarchical porous structures that confer highly-specific cellular functions. Despite advances in fabrication processes, it is still very challenging to emulate the hierarchical porous collagen architecture found in most native tissues. Hence, the ability to recreate such hierarchical porous structures would result in biomimetic tissue-engineered constructs. Here, a single-step drop-on-demand (DOD) bioprinting strategy is proposed to fabricate hierarchical porous collagen-based hydrogels. Printable macromolecule-based bio-inks (polyvinylpyrrolidone, PVP) have been developed and printed in a DOD manner to manipulate the porosity within the multi-layered collagen-based hydrogels by altering the collagen fibrillogenesis process. The experimental results have indicated that hierarchical porous collagen structures could be achieved by controlling the number of macromolecule-based bio-ink droplets printed on each printed collagen layer. This facile single-step bioprinting process could be useful for the structural design of collagen-based hydrogels for various tissue engineering applications.

Nanohole and dot patterning processes on quartz substrate by R-θ electron beam lithography and nanoimprinting

NASA Astrophysics Data System (ADS)

Watanabe, Tsuyoshi; Taniguchi, Kazutake; Suzuki, Kouta; Iyama, Hiromasa; Kishimoto, Shuji; Sato, Takashi; Kobayashi, Hideo

2016-06-01

Fine hole and dot patterns with bit pitches (bp’s) of less than 40 nm were fabricated in the circular band area of a quartz substrate by R-θ electron beam lithography (EBL), reactive ion etching (RIE), and nanoimprinting. These patterning processes were studied to obtain minimum pitch sizes of hole and dot patterns without pattern collapse. The patterning on the circular band was aimed to apply these patterning processes to future high-density bit-patterned media (BPM) for hard disk drive (HDD) and permanent memory for the long life archiving of digital data. In hole patterning, a minimum-22-nm-bp and 8.2-nm-diameter pattern (1.3 Tbit/in.2) was obtained on a quartz substrate by optimizing the R-θ EBL and RIE processes. Dot patterns were replicated on another quartz substrate by nanoimprinting using a hole-patterned quartz substrate as a master mold followed by RIE. In dot patterning, a minimum-30-nm-bp and 18.5-nm-diameter pattern (0.7 Tbit/in.2) was obtained by introducing new descum conditions. It was observed that the minimum bp of successful patterning increased as the fabrication process proceeded, i.e., from 20 nm bp in the first EBL process to 30 nm bp in the last quartz dot patterning process. From the measured diameters of the patterns, it was revealed that pattern collapse was apt to occur when the value of average diameter plus 3 sigma of diameter was close to the bp. It was suggested that multiple fabrication processes caused the degradation of pattern quality; therefore, hole patterning is more suitable than dot patterning for future applications owing to the lower quality degradation by its simple fabrication process.

Constitutive Parameter Measurement Using Double Ridge Waveguide

DTIC Science & Technology

2013-03-01

different microwave absorbers. The sample constructed by AFRL is a polymer known commercially as VeroP and was fabricated in a Polyjet 3D printer . The...local 3D printer resources. The acrylic was able to fit similarly to the AFRL sample. The absorber material was formed using laser cut plastic as a...samples. During the sample fabrication process, the 3D printer from Air Force Institute of Technology (AFIT) was used to verify the sample size. The

Fabrication of 3D surface structures using grayscale lithography

NASA Astrophysics Data System (ADS)

Stilson, Christopher; Pal, Rajan; Coutu, Ronald A.

2014-03-01

The ability to design and develop 3D microstructures is important for microelectromechanical systems (MEMS) fabrication. Previous techniques used to create 3D devices included tedious steps in direct writing and aligning patterns onto a substrate followed by multiple photolithography steps using expensive, customized equipment. Additionally, these techniques restricted batch processing and placed limits on achievable shapes. Gray-scale lithography enables the fabrication of a variety of shapes using a single photolithography step followed by reactive ion etching (RIE). Micromachining 3D silicon structures for MEMS can be accomplished using gray-scale lithography along with dry anisotropic etching. In this study, we investigated: using MATLAB for mask designs; feasibility of using 1 μm Heidelberg mask maker to direct write patterns onto photoresist; using RIE processing to etch patterns into a silicon substrate; and the ability to tailor etch selectivity for precise fabrication. To determine etch rates and to obtain desired etch selectivity, parameters such as gas mixture, gas flow, and electrode power were studied. This process successfully demonstrates the ability to use gray-scale lithography and RIE for use in the study of micro-contacts. These results were used to produce a known engineered non-planer surface for testing micro-contacts. Surface structures are between 5 μm and 20 μm wide with varying depths and slopes based on mask design and etch rate selectivity. The engineered surfaces will provide more insight into contact geometries and failure modes of fixed-fixed micro-contacts.

3D printing of nano- and micro-structures

NASA Astrophysics Data System (ADS)

Ramasamy, Mouli; Varadan, Vijay K.

2016-04-01

Additive manufacturing or 3D printing techniques are being vigorously investigated as a replacement to the traditional and conventional methods in fabrication to bring forth cost and time effective approaches. Introduction of 3D printing has led to printing micro and nanoscale structures including tissues and organelles, bioelectric sensors and devices, artificial bones and transplants, microfluidic devices, batteries and various other biomaterials. Various microfabrication processes have been developed to fabricate micro components and assemblies at lab scale. 3D Fabrication processes that can accommodate the functional and geometrical requirements to realize complicated structures are becoming feasible through advances in additive manufacturing. This advancement could lead to simpler development mechanisms of novel components and devices exhibiting complex features. For instance, development of microstructure electrodes that can penetrate the epidermis of the skin to collect the bio potential signal may prove very effective than the electrodes that measure signal from the skin's surface. The micro and nanostructures will have to possess extraordinary material and mechanical properties for its dexterity in the applications. A substantial amount of research being pursued on stretchable and flexible devices based on PDMA, textiles, and organic electronics. Despite the numerous advantages these substrates and techniques could solely offer, 3D printing enables a multi-dimensional approach towards finer and complex applications. This review emphasizes the use of 3D printing to fabricate micro and nanostructures for that can be applied for human healthcare.

Optimized micromirror arrays for adaptive optics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Michalicek, M. Adrian

This paper describes the design, layout, fabrication, and surface characterization of highly optimized surface micromachined micromirror devices. Design considerations and fabrication capabilities are presented. These devices are fabricated in the state-of-the-art, four-level, planarized, ultra-low-stress polysilicon process available at Sandia National Laboratories known as the Sandia Ultra-planar Multi-level MEMS Technology (SUMMiT). This enabling process permits the development of micromirror devices with near-ideal characteristics that have previously been unrealizable in standard three-layer polysilicon processes. The reduced 1 {mu}m minimum feature sizes and 0.1 {mu}m mask resolution make it possible to produce dense wiring patterns and irregularly shaped flexures. Likewise, mirror surfaces canmore » be uniquely distributed and segmented in advanced patterns and often irregular shapes in order to minimize wavefront error across the pupil. The ultra-low-stress polysilicon and planarized upper layer allow designers to make larger and more complex micromirrors of varying shape and surface area within an array while maintaining uniform performance of optical surfaces. Powerful layout functions of the AutoCAD editor simplify the design of advanced micromirror arrays and make it possible to optimize devices according to the capabilities of the fabrication process. Micromirrors fabricated in this process have demonstrated a surface variance across the array from only 2{endash}3 nm to a worst case of roughly 25 nm while boasting active surface areas of 98{percent} or better. Combining the process planarization with a {open_quotes}planarized-by-design{close_quotes} approach will produce micromirror array surfaces that are limited in flatness only by the surface deposition roughness of the structural material. Ultimately, the combination of advanced process and layout capabilities have permitted the fabrication of highly optimized micromirror arrays for adaptive optics. {copyright} {ital 1999 American Institute of Physics.}« less

3D printing in chemical engineering and catalytic technology: structured catalysts, mixers and reactors.

PubMed

Parra-Cabrera, Cesar; Achille, Clement; Kuhn, Simon; Ameloot, Rob

2018-01-02

Computer-aided fabrication technologies combined with simulation and data processing approaches are changing our way of manufacturing and designing functional objects. Also in the field of catalytic technology and chemical engineering the impact of additive manufacturing, also referred to as 3D printing, is steadily increasing thanks to a rapidly decreasing equipment threshold. Although still in an early stage, the rapid and seamless transition between digital data and physical objects enabled by these fabrication tools will benefit both research and manufacture of reactors and structured catalysts. Additive manufacturing closes the gap between theory and experiment, by enabling accurate fabrication of geometries optimized through computational fluid dynamics and the experimental evaluation of their properties. This review highlights the research using 3D printing and computational modeling as digital tools for the design and fabrication of reactors and structured catalysts. The goal of this contribution is to stimulate interactions at the crossroads of chemistry and materials science on the one hand and digital fabrication and computational modeling on the other.

3D printing in social education: Eki-Fab and student PBL

NASA Astrophysics Data System (ADS)

Makino, Masato; Saito, Azusa; Kodama, Mai; Takamatsu, Kyuuichiro; Tamate, Hideaki; Sakai, Kazuyuki; Wada, Masato; Khosla, Ajit; Kawakami, Masaru; Furukawa, Hidemitsu

2017-04-01

Additive manufacturing or 3D printer is one of the most innovative material processing methods. We are considering that human resources for 3D printing would be needed in the future. To educate the abilities of the digital fabrication, we have the public digital fabrication space "Eki-Fab" for junior and high school students and Project Based Learning (PBL) class for undergraduate students. Eki-Fab is held on every Saturday at the Yonezawa train station. In the "Eki-Fab", anybody can study the utilizing of 3D printer and modeling technics under the instruction of staff in Yamagata University. In the PBL class, we have the class every Thursday. The students get the techniques of the digital fabrication through the PBL.

Low-Pressure Vapor-Assisted Solution Process for Thiocyanate-Based Pseudohalide Perovskite Solar Cells.

PubMed

Chiang, Yu-Hsien; Cheng, Hsin-Min; Li, Ming-Hsien; Guo, Tzung-Fang; Chen, Peter

2016-09-22

In this report, we fabricated thiocyanate-based perovskite solar cells with low-pressure vapor-assisted solution process (LP-VASP) method. Photovoltaic performances are evaluated with detailed materials characterizations. Scanning electron microscopy images show that SCN-based perovskite films fabricated using LP-VASP have long-range uniform morphology and large grain sizes up to 1 μm. The XRD and Raman spectra were employed to observe the characteristic peaks for both SCN-based and pure CH 3 NH 3 PbI 3 perovskite. We observed that the Pb(SCN) 2 film transformed to PbI 2 before the formation of perovskite film. X-ray photoemission spectra (XPS) show that only a small amount of S remained in the film. Using LP-VASP method, we fabricated SCN-based perovskite solar cells and achieved a power conversion efficiency of 12.72 %. It is worth noting that the price of Pb(SCN) 2 is only 4 % of PbI 2 . These results demonstrate that pseudo-halide perovskites are promising materials for fabricating low-cost perovskite solar cells. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Geyuan

My research projects are focused on application of photonics, optics and micro- fabrication technology in energy related fields. Photonic crystal fabrication research has the potential to help us generate and use light more efficiently. In order to fabricate active 3D woodpile photonic structure devices, a woodpile template is needed to enable the crystal growth process. We developed a silica woodpile template fabrication process based on two polymer transfer molding technique. A silica woodpile template is demonstrated to work with temperature up to 900 C. It provides a more economical way to explore making better 3D active woodpile photonic devices likemore » 3D photonic light emitting diodes (LED). Optical research on solar cell testing has the potential to make our energy generation more e cient and greener. PL imaging and LBIC mapping are used to measure CdTe solar cells with different back contacts. A strong correlation between PL image defects and LBIC map defects is observed. This opens up potential application for PL imaging in fast solar cell inspection. 2D laser IV scan shows its usage in 2D parameter mapping. We show its ability to generate important information about solar cell performance locally around PL image defects.« less

Recent Advances in 3D Printing of Aliphatic Polyesters

PubMed Central

Frone, Adriana Nicoleta; Brandabur, Călin

2017-01-01

3D printing represents a valuable alternative to traditional processing methods, clearly demonstrated by the promising results obtained in the manufacture of various products, such as scaffolds for regenerative medicine, artificial tissues and organs, electronics, components for the automotive industry, art objects and so on. This revolutionary technique showed unique capabilities for fabricating complex structures, with precisely controlled physical characteristics, facile tunable mechanical properties, biological functionality and easily customizable architecture. In this paper, we provide an overview of the main 3D-printing technologies currently employed in the case of poly (lactic acid) (PLA) and polyhydroxyalkanoates (PHA), two of the most important classes of thermoplastic aliphatic polyesters. Moreover, a short presentation of the main 3D-printing methods is briefly discussed. Both PLA and PHA, in the form of filaments or powder, proved to be suitable for the fabrication of artificial tissue or scaffolds for bone regeneration. The processability of PLA and PHB blends and composites fabricated through different 3D-printing techniques, their final characteristics and targeted applications in bioengineering are thoroughly reviewed. PMID:29295559

Turning the undesired voids in silicon into a tool: In-situ fabrication of free-standing 3C-SiC membranes

NASA Astrophysics Data System (ADS)

Khazaka, Rami; Michaud, Jean François; Vennéguès, Philippe; Alquier, Daniel; Portail, Marc

2017-02-01

In this contribution, we present a method to form free-standing cubic silicon carbide (3C-SiC) membranes in-situ during the growth stage. To do so, we exploit the presence of voids in the silicon (Si) epilayer underneath the 3C-SiC membrane, in stark contrast to the conventional view of voids as defects. The shape and the size of the 3C-SiC membranes can be controlled by a preceding patterning step of the Si epilayer. Afterwards, by controlling the expansion of voids in Si, the structured sacrificial layer is consumed during the 3C-SiC growth step. Consequently, the membranes are grown and released simultaneously in a single step process. This straightforward technique is expected to markedly simplify the fabrication process of membranes by reducing the fabrication duration and cost. Furthermore, it helps to overcome several technical issues and presents the cornerstone for micro and nano-electromechanical systems applications, profiting from the outstanding properties of cubic silicon carbide.

Fabrication of solution processed 3D nanostructured CuInGaS₂ thin film solar cells.

PubMed

Chu, Van Ben; Cho, Jin Woo; Park, Se Jin; Hwang, Yun Jeong; Park, Hoo Keun; Do, Young Rag; Min, Byoung Koun

2014-03-28

In this study we demonstrate the fabrication of CuInGaS₂ (CIGS) thin film solar cells with a three-dimensional (3D) nanostructure based on indium tin oxide (ITO) nanorod films and precursor solutions (Cu, In and Ga nitrates in alcohol). To obtain solution processed 3D nanostructured CIGS thin film solar cells, two different precursor solutions were applied to complete gap filling in ITO nanorods and achieve the desirable absorber film thickness. Specifically, a coating of precursor solution without polymer binder material was first applied to fill the gap between ITO nanorods followed by deposition of the second precursor solution in the presence of a binder to generate an absorber film thickness of ∼1.3 μm. A solar cell device with a (Al, Ni)/AZO/i-ZnO/CdS/CIGS/ITO nanorod/glass structure was constructed using the CIGS film, and the highest power conversion efficiency was measured to be ∼6.3% at standard irradiation conditions, which was 22.5% higher than the planar type of CIGS solar cell on ITO substrate fabricated using the same precursor solutions.

Chemical vapor deposition growth

NASA Technical Reports Server (NTRS)

Ruth, R. P.; Manasevit, H. M.; Kenty, J. L.; Moudy, L. A.; Simpson, W. I.; Yang, J. J.

1976-01-01

The chemical vapor deposition (CVD) method for the growth of Si sheet on inexpensive substrate materials is investigated. The objective is to develop CVD techniques for producing large areas of Si sheet on inexpensive substrate materials, with sheet properties suitable for fabricating solar cells meeting the technical goals of the Low Cost Silicon Solar Array Project. Specific areas covered include: (1) modification and test of existing CVD reactor system; (2) identification and/or development of suitable inexpensive substrate materials; (3) experimental investigation of CVD process parameters using various candidate substrate materials; (4) preparation of Si sheet samples for various special studies, including solar cell fabrication; (5) evaluation of the properties of the Si sheet material produced by the CVD process; and (6) fabrication and evaluation of experimental solar cell structures, using standard and near-standard processing techniques.

3D Printing: 3D Printing of Conductive Complex Structures with In Situ Generation of Silver Nanoparticles (Adv. Mater. 19/2016).

PubMed

Fantino, Erika; Chiappone, Annalisa; Roppolo, Ignazio; Manfredi, Diego; Bongiovanni, Roberta; Pirri, Candido Fabrizio; Calignano, Flaviana

2016-05-01

On page 3712, E. Fantino, A. Chiappone, and co-workers fabricate conductive 3D hybrid structures by coupling the photo-reduction of metal precursors with 3D printing technology. The generated structures consist of metal nanoparticles embedded in a polymer matrix shaped into complex multilayered architectures. 3D conductive structures are fabricated with a digital light-processing printer incorporating silver salt into photocurable formulations. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Large Area 2D and 3D Colloidal Photonic Crystals Fabricated by a Roll-to-Roll Langmuir-Blodgett Method.

PubMed

Parchine, Mikhail; McGrath, Joe; Bardosova, Maria; Pemble, Martyn E

2016-06-14

We present our results on the fabrication of large area colloidal photonic crystals on flexible poly(ethylene terephthalate) (PET) film using a roll-to-roll Langmuir-Blodgett technique. Two-dimensional (2D) and three-dimensional (3D) colloidal photonic crystals from silica nanospheres (250 and 550 nm diameter) with a total area of up to 340 cm(2) have been fabricated in a continuous manner compatible with high volume manufacturing. In addition, the antireflective properties and structural integrity of the films have been enhanced via the use of a second roll-to-roll process, employing a slot-die coating of an optical adhesive over the photonic crystal films. Scanning electron microscopy images, atomic force microscopy images, and UV-vis optical transmission and reflection spectra of the fabricated photonic crystals are analyzed. This analysis confirms the high quality of the 2D and 3D photonic crystals fabricated by the roll-to-roll LB technique. Potential device applications of the large area 2D and 3D colloidal photonic crystals on flexible PET film are briefly reviewed.

Low-Temperature Forming of Beta Titanium Alloys

NASA Technical Reports Server (NTRS)

Kaneko, R. S.; Woods, C. A.

1983-01-01

Low cost methods for titanium structural fabrication using advanced cold-formable beta alloys were investigated for application in a Mach 2.7 supersonic cruise vehicle. This work focuses on improving processing and structural efficiencies as compared with standard hot formed and riveted construction of alpha-beta alloy sheet structure. Mechanical property data and manufacturing parameters were developed for cold forming, brazing, welding, and processing Ti-15V-3Cr-3Sn-3Al sheet, and Ti-3Al-8V-6Cr-4Zr on a more limited basis. Cost and structural benefits were assessed through the fabrication and evaluation of large structural panels. The feasibility of increasing structural efficiency of beta titanium structure by selective reinforcement with metal matrix composite was also explored.

Compact Electron Gun Based on Secondary Emission Through Ionic Bombardment

PubMed Central

Diop, Babacar; Bonnet, Jean; Schmid, Thomas; Mohamed, Ajmal

2011-01-01

We present a new compact electron gun based on the secondary emission through ionic bombardment principle. The driving parameters to develop such a gun are to obtain a quite small electron gun for an in-flight instrument performing Electron Beam Fluorescence measurements (EBF) on board of a reentry vehicle in the upper atmosphere. These measurements are useful to characterize the gas flow around the vehicle in terms of gas chemical composition, temperatures and velocity of the flow which usually presents thermo-chemical non-equilibrium. Such an instrument can also be employed to characterize the upper atmosphere if placed on another carrier like a balloon. In ground facilities, it appears as a more practical tool to characterize flows in wind tunnel studies or as an alternative to complex electron guns in industrial processes requiring an electron beam. We describe in this paper the gun which has been developed as well as its different features which have been characterized in the laboratory. PMID:22163896

High Temperature VARTM with LaRC Polyimides

NASA Technical Reports Server (NTRS)

Cano, Roberto J.; Grimsley, Brian W.; Jensen, Brian J.; Kellen, Charles B.

2004-01-01

Recent work at NASA Langley Research Center (LaRC) has concentrated on developing new polyimide resin systems for advanced aerospace applications that can be processed without the use of an autoclave. Polyimide composites are very attractive for applications that require a high strength to weight ratio and thermal stability. Vacuum assisted resin transfer molding (VARTM) has shown potential to reduce the manufacturing cost of composite structures. In VARTM, the fibrous preform is infiltrated on a rigid tool surface contained beneath a flexible vacuum bag. Both resin injection and fiber compaction are achieved under pressures of 101.3 KPa or less. Recent studies have demonstrated the feasibility of the VARTM process for fabrication of void free structures utilizing epoxy resin systems with fiber volume fractions approaching 60%. In this work, the VARTM process has been extended to the fabrication of composite panels from polyimide systems developed at the Langley Research Center. This work has focused on processing LARC(trademark) PETI-8 (Langley Research Center Phenylethynyl Terminated Imide- 8), an aromatic polyimide based on 3,3',4,4' -biphenyltetracarboxylic dianhydride, a 50:50 molar ratio of 3,4'-oxydianiline and 1,3-bis(3-aminophenoxy)benzene, with 4-phenylethynylphthalic anhydride as the endcapping agent. Various molecular weight versions were investigated to determine their feasibility of being processed by VARTM at elevated temperatures. An injection temperature of approximately 280 C was required to achieve the necessary viscosity (<5 Poise) for flow at VARTM pressures. Laminate quality and initial mechanical properties are presented for LARC(trademark) PETI-8 and 6k IM7 uniweave fabric.

High performance fuel electrodes fabricated by electroless plating of copper on BaZr0.8Ce0.1Y0.1O3-δ proton-conducting ceramic

NASA Astrophysics Data System (ADS)

Patki, Neil S.; Way, J. Douglas; Ricote, Sandrine

2017-10-01

The stability of copper at high temperatures in reducing and hydrocarbon-containing atmospheres makes it a good candidate for fabricating fuel electrodes on proton-conducting ceramics, such as BaZr0.9-xCexY0.1O3-δ (BZCY). In this work, the electrochemical performance of Cu-based electrodes fabricated by electroless plating (ELP) on BaZr0.8Ce0.1Y0.1O3-δ is studied with impedance spectroscopy. Three activation catalysts (Pd, Ru, and Cu) are investigated and ELP is compared to a commercial Cu paste (ESL 2312-G) for electrode fabrication. The area specific resistances (ASR) for Pd, Ru, and Cu activations at 700 °C in moist 5% H2 in Ar are 2.1, 3.2, and 13.4 Ω cm2, respectively. That is a 1-2 orders of magnitude improvement over the commercial Cu paste (192 Ω cm2). Furthermore, the ASR has contributions from electrode processes and charge transfer at the electrode/electrolyte interface. Additionally, the morphology of the as-fabricated electrode is unaffected by the activation catalyst. However, heat treatment at 750 °C in H2 for 24 h leads to sintering and large reorganization of the electrode fabricated with Cu activation (micron sized pores seen in the tested sample), while Pd and Ru activations are immune to such reorganization. Thus, Pd and Ru are identified as candidates for future work with improvements to charge transfer required for the former, and better electrode processes required for the latter.

Novel Bonding Process for CBW Protective Electrospun Fabric Laminates Phase 2

DTIC Science & Technology

2011-12-01

ir Fl ow R es is ta nc e (1 /m ) F-3742 Figure 3. Summary chart of the breathability and permeability of several fabrics tested at the U.S. Army... dryer deposits due to faster solvent evaporation during the deposition process. We contacted Noveon (manufacturer of Estane) and they indicated...expected, the increase in concentration of THF resulted in dryer deposits. However, at these levels of higher vapor pressure solvent blends, the Taylor

Integrated optics technology study

NASA Technical Reports Server (NTRS)

Chen, B.

1982-01-01

The materials and processes available for the fabrication of single mode integrated electrooptical components are described. Issues included in the study are: (1) host material and orientation, (2) waveguide formation, (3) optical loss mechanisms, (4) wavelength selection, (5) polarization effects and control, (6) laser to integrated optics coupling,(7) fiber optic waveguides to integrated optics coupling, (8) souces, (9) detectors. The best materials, technology and processes for fabrication of integrated optical components for communications and fiber gyro applications are recommended.

Development of 3D woven cellular structures for adaptive composites based on thermoplastic hybrid yarns

NASA Astrophysics Data System (ADS)

Sennewald, C.; Vorhof, M.; Schegner, P.; Hoffmann, G.; Cherif, C.; Boblenz, J.; Sinapius, M.; Hühne, C.

2018-05-01

Flexible cellular 3D structures with structure-inherent compliance made of fiber-reinforced composites have repeatedly aroused the interest of international research groups. Such structures offer the possibility to meet the increasing demand for flexible and adaptive structures. The aim of this paper is the development of cellular 3D structures based on weaving technology. Considering the desired geometry of the 3D structure, algorithms are developed for the formation of geometry through tissue sub-areas. Subsequently, these sub-areas are unwound into the weaving level and appropriate weave patterns are developed. A particular challenge is the realization of compliant mechanisms in the woven fabric. This can be achieved either by combining different materials or, in particular, by implementing large stiffness gradients by means of varying the woven fabrics thickness, whereas differences in wall thickness have to be realized with a factor of 1:10. A manufacturing technology based on the weaving process is developed for the realization of the developed 3D cellular structures. To this end, solutions for the processing of hybrid thermoplastic materials (e.g. tapes), solutions for the integration of inlays in the weaving process (thickening of partial areas), and solutions for tissue retraction, as well as for the fabric pull-off (linear pull-off system) are being developed. In this way, woven cellular 3D structures with woven outer layers and woven joint areas (compliance) can be realized in a single process step and are subsequently characterized.

Some problems in mechanics of growing solids with applications to AM technologies

NASA Astrophysics Data System (ADS)

Manzhirov, A. V.

2018-04-01

Additive Manufacturing (AM) technologies are an exciting area of the modern industrial revolution and have applications in engineering, medicine, electronics, aerospace industry, etc. AM enables cost-effective production of customized geometry and parts by direct fabrication from 3D data and mathematical models. Despite much progress in AM technologies, problems of mechanical analysis for AM fabricated parts yet remain to be solved. This paper deals with three main mechanical problems: the onset of residual stresses, which occur in the AM process and can lead to failure of the parts, the distortion of the final shape of AM fabricated parts, and the development of technological solutions aimed at improving existing AM technologies and creating new ones. An approach proposed deals with the construction of adequate analytical model and effective methods for the simulation of AM processes for fabricated solid parts.

High performance printed oxide field-effect transistors processed using photonic curing.

PubMed

Garlapati, Suresh Kumar; Marques, Gabriel Cadilha; Gebauer, Julia Susanne; Dehm, Simone; Bruns, Michael; Winterer, Markus; Tahoori, Mehdi Baradaran; Aghassi-Hagmann, Jasmin; Hahn, Horst; Dasgupta, Subho

2018-06-08

Oxide semiconductors are highly promising candidates for the most awaited, next-generation electronics, namely, printed electronics. As a fabrication route for the solution-processed/printed oxide semiconductors, photonic curing is becoming increasingly popular, as compared to the conventional thermal curing method; the former offers numerous advantages over the latter, such as low process temperatures and short exposure time and thereby, high throughput compatibility. Here, using dissimilar photonic curing concepts (UV-visible light and UV-laser), we demonstrate facile fabrication of high performance In 2 O 3 field-effect transistors (FETs). Beside the processing related issues (temperature, time etc.), the other known limitation of oxide electronics is the lack of high performance p-type semiconductors, which can be bypassed using unipolar logics from high mobility n-type semiconductors alone. Interestingly, here we have found that our chosen distinct photonic curing methods can offer a large variation in threshold voltage, when they are fabricated from the same precursor ink. Consequently, both depletion and enhancement-mode devices have been achieved which can be used as the pull-up and pull-down transistors in unipolar inverters. The present device fabrication recipe demonstrates fast processing of low operation voltage, high performance FETs with large threshold voltage tunability.

High performance printed oxide field-effect transistors processed using photonic curing

NASA Astrophysics Data System (ADS)

Garlapati, Suresh Kumar; Cadilha Marques, Gabriel; Gebauer, Julia Susanne; Dehm, Simone; Bruns, Michael; Winterer, Markus; Baradaran Tahoori, Mehdi; Aghassi-Hagmann, Jasmin; Hahn, Horst; Dasgupta, Subho

2018-06-01

Oxide semiconductors are highly promising candidates for the most awaited, next-generation electronics, namely, printed electronics. As a fabrication route for the solution-processed/printed oxide semiconductors, photonic curing is becoming increasingly popular, as compared to the conventional thermal curing method; the former offers numerous advantages over the latter, such as low process temperatures and short exposure time and thereby, high throughput compatibility. Here, using dissimilar photonic curing concepts (UV–visible light and UV-laser), we demonstrate facile fabrication of high performance In2O3 field-effect transistors (FETs). Beside the processing related issues (temperature, time etc.), the other known limitation of oxide electronics is the lack of high performance p-type semiconductors, which can be bypassed using unipolar logics from high mobility n-type semiconductors alone. Interestingly, here we have found that our chosen distinct photonic curing methods can offer a large variation in threshold voltage, when they are fabricated from the same precursor ink. Consequently, both depletion and enhancement-mode devices have been achieved which can be used as the pull-up and pull-down transistors in unipolar inverters. The present device fabrication recipe demonstrates fast processing of low operation voltage, high performance FETs with large threshold voltage tunability.

Chemical vapor deposition growth

NASA Technical Reports Server (NTRS)

Ruth, R. P.; Manasevit, H. M.; Campbell, A. G.; Johnson, R. E.; Kenty, J. L.; Moudy, L. A.; Shaw, G. L.; Simpson, W. I.; Yang, J. J.

1978-01-01

The objective was to investigate and develop chemical vapor deposition (CVD) techniques for the growth of large areas of Si sheet on inexpensive substrate materials, with resulting sheet properties suitable for fabricating solar cells that would meet the technical goals of the Low Cost Silicon Solar Array Project. The program involved six main technical tasks: (1) modification and test of an existing vertical-chamber CVD reactor system; (2) identification and/or development of suitable inexpensive substrate materials; (3) experimental investigation of CVD process parameters using various candidate substrate materials; (4) preparation of Si sheet samples for various special studies, including solar cell fabrication; (5) evaluation of the properties of the Si sheet material produced by the CVD process; and (6) fabrication and evaluation of experimental solar cell structures, using impurity diffusion and other standard and near-standard processing techniques supplemented late in the program by the in situ CVD growth of n(+)/p/p(+) sheet structures subsequently processed into experimental cells.

Bayesian approach for three-dimensional aquifer characterization at the Hanford 300 Area

DOE Office of Scientific and Technical Information (OSTI.GOV)

Murakami, Haruko; Chen, X.; Hahn, Melanie S.

2010-10-21

This study presents a stochastic, three-dimensional characterization of a heterogeneous hydraulic conductivity field within DOE's Hanford 300 Area site, Washington, by assimilating large-scale, constant-rate injection test data with small-scale, three-dimensional electromagnetic borehole flowmeter (EBF) measurement data. We first inverted the injection test data to estimate the transmissivity field, using zeroth-order temporal moments of pressure buildup curves. We applied a newly developed Bayesian geostatistical inversion framework, the method of anchored distributions (MAD), to obtain a joint posterior distribution of geostatistical parameters and local log-transmissivities at multiple locations. The unique aspects of MAD that make it suitable for this purpose are itsmore » ability to integrate multi-scale, multi-type data within a Bayesian framework and to compute a nonparametric posterior distribution. After we combined the distribution of transmissivities with depth-discrete relative-conductivity profile from EBF data, we inferred the three-dimensional geostatistical parameters of the log-conductivity field, using the Bayesian model-based geostatistics. Such consistent use of the Bayesian approach throughout the procedure enabled us to systematically incorporate data uncertainty into the final posterior distribution. The method was tested in a synthetic study and validated using the actual data that was not part of the estimation. Results showed broader and skewed posterior distributions of geostatistical parameters except for the mean, which suggests the importance of inferring the entire distribution to quantify the parameter uncertainty.« less

Costs of Promoting Exclusive Breastfeeding at Community Level in Three Sites in South Africa

PubMed Central

Nkonki, Lungiswa Leonora; Daviaud, Emmanuelle; Jackson, Debra; Chola, Lumbwe; Doherty, Tanya; Chopra, Mickey; Robberstad, Bjarne

2014-01-01

Background Community-based peer support has been shown to be effective in improving exclusive breastfeeding rates in a variety of settings. Methods We conducted a cost analysis of a community cluster randomised-controlled trial (Promise-EBF), aimed at promoting exclusive infant feeding in three sites in South Africa. The costs were considered from the perspective of health service providers. Peer supporters in this trial visited women to support exclusive infant feeding, once antenatally and four times postpartum. Results The total economic cost of the Promise-EBF intervention was US$393 656, with average costs per woman and per visit of US$228 and US$52, respectively. The average costs per woman and visit in an operational ‘non research’ scenario were US$137 and US$32 per woman and visit, respectively. Investing in the promotion of exclusive infant feeding requires substantial financial commitment from policy makers. Extending the tasks of multi-skilled community health workers (CHWs) to include promoting exclusive infant feeding is a potential option for reducing these costs. In order to avoid efficiency losses, we recommend that the time requirements for delivering the promotion of exclusive infant feeding are considered when integrating it within the existing activities of CHWs. Discussion This paper focuses on interventions for exclusive infant feeding, but its findings more generally illustrate the importance of documenting and quantifying factors that affect the feasibility and sustainability of community-based interventions, which are receiving increased focus in low income settings. PMID:24427264

Long-term effects of earlier initiated continuous Kangaroo Mother Care (KMC) for low-birth-weight (LBW) infants in Madagascar.

PubMed

Nagai, Shuko; Yonemoto, Naohiro; Rabesandratana, Norotiana; Andrianarimanana, Diavolana; Nakayama, Takeo; Mori, Rintaro

2011-12-01

To examine the long-term effects of earlier initiated continuous Kangaroo Mother Care (KMC) for relatively stable low-birth-weight (LBW) infants in a resource-limited country. A randomized controlled trial with long-term follow-up was performed in LBW infants in Madagascar. Earlier continuous KMC (intervention group) was initiated as soon as possible within 24 h postbirth, and later continuous KMC (control group: conventional care) was initiated after complete stabilization. Outcome measures were mortality or readmission, nutritional indicators at 6-12 months postbirth and feeding condition at 6 months postbirth (ClinicalTrials.gov, NCT00531492). A total of 72 infants were followed for mortality or readmission at 6-12 months postbirth. There was no difference between the two groups (7/36 vs. 7/36, Risk ratio (RR), 1.00; 95% CIs, 0.39-2.56; p = 1.00). The proportion of exclusive breast feeding (EBF) at 6 months postbirth was significantly higher with earlier KMC than later KMC (12/29 vs. 4/26; RR 2.69; 95% CIs, 1.00-7.31; p = 0.04). There were no differences in nutritional indicators between the two groups at 6-12 months postbirth. Earlier initiated continuous KMC results in a significantly higher proportion of EBF at 6 months postbirth. Further larger-scale long-term evaluations of earlier initiated continuous KMC for LBW infants are needed. © 2011 The Author(s)/Acta Paediatrica © 2011 Foundation Acta Paediatrica.

Evaluation and rational design of guide RNAs for efficient CRISPR/Cas9-mediated mutagenesis in Ciona.

PubMed

Gandhi, Shashank; Haeussler, Maximilian; Razy-Krajka, Florian; Christiaen, Lionel; Stolfi, Alberto

2017-05-01

The CRISPR/Cas9 system has emerged as an important tool for various genome engineering applications. A current obstacle to high throughput applications of CRISPR/Cas9 is the imprecise prediction of highly active single guide RNAs (sgRNAs). We previously implemented the CRISPR/Cas9 system to induce tissue-specific mutations in the tunicate Ciona. In the present study, we designed and tested 83 single guide RNA (sgRNA) vectors targeting 23 genes expressed in the cardiopharyngeal progenitors and surrounding tissues of Ciona embryo. Using high-throughput sequencing of mutagenized alleles, we identified guide sequences that correlate with sgRNA mutagenesis activity and used this information for the rational design of all possible sgRNAs targeting the Ciona transcriptome. We also describe a one-step cloning-free protocol for the assembly of sgRNA expression cassettes. These cassettes can be directly electroporated as unpurified PCR products into Ciona embryos for sgRNA expression in vivo, resulting in high frequency of CRISPR/Cas9-mediated mutagenesis in somatic cells of electroporated embryos. We found a strong correlation between the frequency of an Ebf loss-of-function phenotype and the mutagenesis efficacies of individual Ebf-targeting sgRNAs tested using this method. We anticipate that our approach can be scaled up to systematically design and deliver highly efficient sgRNAs for the tissue-specific investigation of gene functions in Ciona. Copyright © 2017 Elsevier Inc. All rights reserved.

One-Step Solvent Evaporation-Assisted 3D Printing of Piezoelectric PVDF Nanocomposite Structures.

PubMed

Bodkhe, Sampada; Turcot, Gabrielle; Gosselin, Frederick P; Therriault, Daniel

2017-06-21

Development of a 3D printable material system possessing inherent piezoelectric properties to fabricate integrable sensors in a single-step printing process without poling is of importance to the creation of a wide variety of smart structures. Here, we study the effect of addition of barium titanate nanoparticles in nucleating piezoelectric β-polymorph in 3D printable polyvinylidene fluoride (PVDF) and fabrication of the layer-by-layer and self-supporting piezoelectric structures on a micro- to millimeter scale by solvent evaporation-assisted 3D printing at room temperature. The nanocomposite formulation obtained after a comprehensive investigation of composition and processing techniques possesses a piezoelectric coefficient, d 31 , of 18 pC N -1 , which is comparable to that of typical poled and stretched commercial PVDF film sensors. A 3D contact sensor that generates up to 4 V upon gentle finger taps demonstrates the efficacy of the fabrication technique. Our one-step 3D printing of piezoelectric nanocomposites can form ready-to-use, complex-shaped, flexible, and lightweight piezoelectric devices. When combined with other 3D printable materials, they could serve as stand-alone or embedded sensors in aerospace, biomedicine, and robotic applications.

Capillary Origami Inspired Fabrication of Complex 3D Hydrogel Constructs.

PubMed

Li, Moxiao; Yang, Qingzhen; Liu, Hao; Qiu, Mushu; Lu, Tian Jian; Xu, Feng

2016-09-01

Hydrogels have found broad applications in various engineering and biomedical fields, where the shape and size of hydrogels can profoundly influence their functions. Although numerous methods have been developed to tailor 3D hydrogel structures, it is still challenging to fabricate complex 3D hydrogel constructs. Inspired by the capillary origami phenomenon where surface tension of a droplet on an elastic membrane can induce spontaneous folding of the membrane into 3D structures along with droplet evaporation, a facile strategy is established for the fabrication of complex 3D hydrogel constructs with programmable shapes and sizes by crosslinking hydrogels during the folding process. A mathematical model is further proposed to predict the temporal structure evolution of the folded 3D hydrogel constructs. Using this model, precise control is achieved over the 3D shapes (e.g., pyramid, pentahedron, and cube) and sizes (ranging from hundreds of micrometers to millimeters) through tuning membrane shape, dimensionless parameter of the process (elastocapillary number Ce ), and evaporation time. This work would be favorable to multiple areas, such as flexible electronics, tissue regeneration, and drug delivery. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Performance of resin transfer molded multiaxial warp knit composites

NASA Technical Reports Server (NTRS)

Dexter, H. Benson; Hasko, Gregory H.

1993-01-01

Composite materials that are subjected to complex loads have traditionally been fabricated with multidirectionally oriented prepreg tape materials. Some of the problems associated with this type of construction include low delamination resistance, poor out-of-plane strength, and labor intensive fabrication processes. Textile reinforced composites with through-the-thickness reinforcement have the potential to solve some of these problems. Recently, a relatively new class of noncrimp fabrics designated as multiaxial warp knits have been developed to minimize some of the high cost and damage tolerance concerns. Multiple stacks of warp knit fabrics can be knitted or stitched together to reduce layup labor cost. The through-the-thickness reinforcement can provide significant improvements in damage tolerance and out-of-plane strength. Multilayer knitted/stitched preforms, in conjunction with resin transfer molding (RTM), offer potential for significant cost savings in fabrication of primary aircraft structures. The objectives of this investigation were to conduct RTM processing studies and to characterize the mechanical behavior of composites reinforced with three multiaxial warp knit fabrics. The three fabrics investigated were produced by Hexcel and Milliken in the United States, and Saerbeck in Germany. Two resin systems, British Petroleum E9O5L and 3M PR 500, were characterized for RTM processing. The performance of Hexcel and Milliken quasi-isotropic knitted fabrics are compared to conventional prepreg tape laminates. The performance of the Saerbeck fabric is compared to uniweave wing skin layups being investigated by Douglas Aircraft Company in the NASA Advanced Composites Technology (ACT) program. Tests conducted include tension, open hole tension, compression, open hole compression, and compression after impact. The effects of fabric defects, such as misaligned fibers and gaps between tows, on material performance are also discussed. Estimated material and labor cost savings are projected for the Saerbeck fabric as compared to uniweave fabric currently being used by Douglas in the NASA ACT wing development program.