bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of Case-based Small Group Learning on Daycare Center Teachers' Coping Ability in Emergency Situations: Focus on Daily Life and Cardiopulmonary Resuscitation.
Authors: Choi Eun Ju
Published: August 2013

PURPOSE: This study was conducted to examine the effects of case-based learning on the coping ability of daycare center teachers in emergency situations. In the study knowledge of emergency treatment methods, attitude, intention and ability to perform CPR between were examined in an experimental group (daycare center teachers who participated in the small groups discussing case studies and comparing them with their own experience) and a control group.METHODS: The study was designed using a nonequivalent control group pretest-posttest design. Sixty-four teachers were recruited from 40 child daycare centers in S city located in J province. Thirty-three teachers were assigned to experimental group and participated in the case-based small group learning. The data were analyzed using the SPSS 18.0 program to perform chi2-test, Pearson correlation coefficients and t-test.RESULTS: The experimental group showed significantly higher posttest scores in knowledge, attitude, intention, and performance ability than those of the control group.CONCLUSION: The study results indicate that case-based small group learning on coping ability in emergency situation is effective in increasing knowledge, attitude, intention, and performance ability for daycare center teachers.
Predictors of Resilience in Adolescents with Cancer.
Authors: Park Young Ok , Son Hong Gwi Ryung , Tak Young Ran
Published: August 2013

PURPOSE: The purpose of this study was to identify the predictors influencing on resilience in adolescents with cancer.METHODS: The participants consisted of 107 parents and 107 adolescents who aged ten and eighteen diagnosed with cancer more than six months and currently receiving outpatient treatment or further management after off-therapy. Data was collected using self-report questionnaires and analyzed by descriptive statistics, t-test, ANOVA, Pearson's correlation, and multiple regression.RESULTS: Resilience was significantly different by religion (t=2.472, p=.045) and number of cancer treatment regimens (F=3.155, p=.047). Family problem-solving communication was also significant by number of cancer treatment regimens (F=3.582, p=.031). The higher social support showed the stronger family hardiness and the better family problem-solving communication. In addition, a positive relationship was found between Family Hardiness Index (FHI) (r=.193, p=.046), Family Problem Solving Communication (FPSC) (r=.226, p=.019) and resilience of adolescents with cancer. FPSC (beta=.356, p=.045) and religion (beta=.441, p=.002) were predictive factors at ages 10-12, FHI (beta=.509, p=.029) and FPSC (beta=.503, p=.037) were predictive factors at ages 13-15 on resilience of adolescents with cancer that explained 16.0% and 24.3% respectively.CONCLUSION: The findings suggest that nursing interventions should focus on enhancing family resilience and resilience of adolescents with cancer.
Effects of the 'Intervention - Mother's Song' on Physical Response and Behavioral State of Low-Birth Weight Infants in a Neonatal Intensive Care Unit.
Authors: Park Ji Sun , Hong Kyung Ja , Bang Kyung Sook
Published: August 2013

PURPOSE: This study was done to identify the effectiveness of the 'intervention - mother's recorded song' on low-birth weight infants in an neonatal intensive care unit (NICU).METHODS: This study was conducted with a nonequivalent control group pre-posttest quasi-experimental design and the participant group was low-birth weight infants who were admitted to the NICU. Forty-eight infants, 24 in each from two groups, the experimental and control group, participated in the study.RESULTS: For physical response according to vital signs, there were no significant statistical differences in heart rate, respiration rate and pulse oximetry saturation between the experimental group and the control group. For behavioral state, there was a significant statistical difference between the experimental and control group.CONCLUSION: The study results indicate that the intervention using mother's song had some significance as a nursing intervention with positive impacts. Such an intervention can help pediatric nurses improve infants' stabilization of their vital signs and behavioral states. By showing the effectiveness of such an intervention, the results of this study provide further evidence-based information in developing the practice of pediatric nursing.
Effects on Maternal Attachment, Parenting Stress, and Maternal Confidence of Systematic Information for Mothers of Premature Infants.
Authors: Choi Hyo Sin , Shin Yeong Hee
Published: August 2013

PURPOSE: The aim of this study was to examine the effects of systematic information on maternal attachment, parenting stress and maternal confidence of mothers of premature infants.METHODS: Using a non-equivalent control group pre-post quasi-experimental design, 42 participants were assigned to one of two groups, an experimental group (n=20), which received systematic information; and a control (n=22), which received the usual discharge education. Prior to the intervention, baseline data were collected (pretest) and then the systematic information was provided four times for the experimental group. Maternal attachment, parenting stress and maternal confidence were measured. Data were collected three times: Seven to 10 days prior to discharge, day of discharge, and two weeks after discharge.RESULTS: Mothers in the experimental group had significantly higher scores in maternal attachment (F=6.16, p=.005), lower parenting stress scores (F=5.56, p=.004), and higher scores for maternal confidence (F=16.50, p<.001) than mothers in the control group. These tendencies were progressively enhanced even two weeks after discharge from the hospital.CONCLUSION: The results indicate that provision of systematic information to mothers with premature infants is an effective intervention to enhance mothers' maternal attachment, decrease parenting stress, and enhance maternal confidence.
Translation and validation of a patient satisfaction survey: The isiXhosa version
Authors: Steyl Tania , Phillips Julie
Published: August 2013

Background: Although the use of surveys has been supported for assessing understanding of health care service quality, it could also be argued that their main function is to quantify perceptions. The importance of assessing patient satisfaction in individuals’ own language has been highlighted in research. However, important culture-specific differences can be revealed during the adaptation process of a scale, and if not attended to can influence the validity ofthe scale.Objectives: The aim of this study was to assess the validity and reliability of the isiXhosa version of the Patient Survey for Quality of Care (PSQC) in primary health care (PHC) facilities in a selected district in the Western Cape, South Africa.Method: The PSQC was translated into isiXhosa by two independant translators and the translated back into English by a third translator. All three translators reviewed the back translation. Face and content validity of the scale were assessed. Fifteen isiXhosa-speaking clients with type 2 diabetes mellitus who had a mean age of 62.27 years (SD 10.33) and came from a randomly selected community health centre participated in the test-retest reliability.Results: Internal consistency of the scale was good (Cronbach alpha 0.70). Alpha values of individual items relating to quality of care as well as items flagged for inferior service quality were between 0.772 and 1.000, indicating good to high internal consistency.Conclusion: Results of this study indicated that the isiXhosa version of the PSQC was as reliable as the English version. It can be implemented at PHC level to assess isiXhosa-speaking patients’ satisfaction with health care services.
The roles of vertical advection and eddy diffusion in the equatorial mesospheric semi-annual oscillation (MSAO)
Authors: Gattinger R. L. , Kyrölä E. , Boone C. D. , Evans W. F. J. , Walker K. A. , McDade I. C. , Bernath P. F. , Llewellyn E. J.
Published: August 2013

Abstract. Observations of the mesospheric semi-annual oscillation (MSAO) in the equatorial region have been reported dating back several decades. Seasonal variations in both species densities and airglow emissions are well documented. The extensive observations available offer an excellent case study for comparison with model simulations. A broad range of MSAO measurements is summarised with emphasis on the 80–100 km region. The objective here is not to address directly the complicated driving forces of the MSAO, but rather to employ a combination of observations and model simulations to estimate the limits of some of the underlying dynamical processes. Photochemical model simulations are included for near-equinox and near-solstice conditions, the two times with notable differences in the observed MSAO parameters. Diurnal tides are incorporated in the model to facilitate comparisons of observations made at different local times. The roles of water vapour as the "driver" species and ozone as the "response" species are examined to test for consistency between the model results and observations. The simulations suggest the interactions between vertical eddy diffusion and background vertical advection play a significant role in the MSAO phenomenon. Further, the simulations imply there are rigid limits on vertical advection rates and eddy diffusion rates. For August at the Equator, 90 km altitude, the derived eddy diffusion rate is approximately 1 × 106 cm2 s−1 and the vertical advection is upwards at 0.8 cm s−1. For April the corresponding values are 4 × 105 cm2 s−1 and 0.1 cm s−1. These results from the current 1-D model simulations will need to be verified by a full 3-D simulation. Exactly how vertical advection and eddy diffusion are related to gravity wave momentum as discussed by Dunkerton (1982) three decades ago remains to be addressed.
Post-Pliocene establishment of the present monsoonal climate in SW China: evidence from the late Pliocene Longmen megaflora
Authors: Su T. , Jacques F. M. B. , Spicer R. A. , Liu Y.-S. , Huang Y.-J. , Xing Y.-W. , Zhou Z.-K.
Published: August 2013

Abstract. The paleoclimate of the late Pliocene Longmen flora from Yongping County located at the southeastern boundary of the Qinghai-Tibet Plateau was reconstructed using two leaf-physiognomy-based methods, i.e., leaf margin analysis (LMA) and Climate Leaf Analysis Multivariate Program (CLAMP), to understand the paleoclimate condition and geographical pattern of monsoonal climate in southwestern China during the late Pliocene. The mean annual temperatures (MATs) estimated by LMA and CLAMP are 17.4 ± 3.3 °C and 17.4 ± 1.3 °C, respectively, compared with 15.9 °C at present. Meanwhile, the growing season precipitation (GSP) estimated by CLAMP is 1735.5 ± 217.7 mm in the Longmen flora, compared with 986.9 mm nowadays. The calculated monsoon intensity index (MSI) of the Longmen flora is significantly lower than that of today. These results appear consistent with previous studies on the late Pliocene floras in western Yunnan based on the coexistence approach (CA), and further suggest that there was a slightly warmer and much wetter climate during the late Pliocene than the present climate in western Yunnan. We conclude that the significant change of the monsoonal climate might have been resulted from the continuous uplift of mountains in western Yunnan, as well as the intensification of the eastern Asian winter monsoon, both occurring concurrently in the post-Pliocene period.
Employment of Inappropriate Technologies in Agriculture: a Recipe for Lower Production
Authors: Osei Kingsley , Boakye Solomon Gyasi , Afriyie Emmanuel , Agyeman Adelaide
Published: August 2013

Maize production practices of four Farmer Based Organizations in the Kpando District of the Volta Region of Ghana were studied prior to the training in Commercial Development and Good Agricultural Practices for the Farmer Based Organizations. Demographic characteristics of respondents and the rate of adoption of available technologies were analyzed using frequencies, percentages and means while regression analysis was used for the yield data. Males constituted 60% of the population whilst 40% were females. The district had a relatively young farming population with 56% of the farmers below 45 years. The level of education of respondents was low. Eighty-two percent of respondents had not attained senior high school education. Majority (56%) of respondents had been farming for less than 20 years. The rate of adoption of technologies was low and maize yields were very low averaging 0.375 t/ha in the district. There were no differences in yields amongst the four FBOs. The yield of farmers could increase significantly when farmers adopt improved agricultural technologies.
The TV in Your Pocket: Development of Liquid‐Crystal Materials for the New Millennium
Authors: Bremer Matthias , Kirsch Peer , Klasen‐Memmer Melanie , Tarumi Kazuaki
Published: August 2013

New liquid crystals with very low viscosity, good mesophase behavior, and high reliability are necessary to achieve the breakthrough from flat computer monitors to large displays for television. Fluorine plays a decisive role not only because of the polarity it induces in organic molecules but also because of its low polarizability and weak propensity for ion solvation. In addition, subtle stereoelectronic effects in fluorine‐containing liquid crystals influence material properties and allow these to be tuned to some extent to achieve the desired outcome. Some fairly sophisticated chemistry is required that is normally ruled out in the specialty chemicals industry because of cost. The television display market is now entering a phase of saturation. The broad availability of the internet has led to an ever increasing tendency for mobile products. Tablet PCs and smartphones require touch‐panel functionality and low power consumption. New LCD modes with high‐performance liquid crystals and additional components, such as polymerizable materials, can be used in such products.
Evaluation of highly compliant magneto‐active elastomers with colossal magnetorheological response
Authors: Stoll Andrea , Mayer Matthias , Monkman Gareth J. , Shamonin Mikhail
Published: August 2013

Highly compliant elastomers with a shear storage modulus as low as 25 Pa are prepared using commercially available silicone, plasticizer, and tactile mutator silicone additive. They are used as matrix material for magneto‐active elastomers (MAEs) with carbonyl iron contents between 0 and 85 wt %. In the absence of an external magnetic field, the storage modulus of MAEs based on two selected mixtures ranges between ∼100 Pa and ∼2000 Pa. Addition of a mutator to the matrix mixture results in a long post‐cure period depending on the curing temperature and the initial mixture. In the presence of a magnetic field, the presented MAEs exhibit a strong magneto‐induced change in storage modulus resulting in a colossal magnetorheological effect of >106 % which is ∼30 times higher than previously reported values. The results are of interest in applications using such elastomers as cell substrates with magnetically tunable rigidity. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 39793.
Mitochondrial fission‐fusion as an emerging key regulator of cell proliferation and differentiation
Authors: Mitra Kasturi
Published: August 2013

Mitochondrial shape change, brought about by molecules that promote either fission or fusion between individual mitochondria, has been documented in several model systems. However, the deeper significance of mitochondrial shape change has only recently begun to emerge: among others, it appears to play a role in the regulation of cell proliferation. Here, I review the emerging interplay between mitochondrial fission‐fusion components with cell cycle regulatory machineries and how that may impact cell differentiation. Regulation of mitochondrial shape may modulate mitochondrial metabolism and/or energetics to promote crosstalk between signaling components and the cell cycle machinery. Focused research in this area will reveal the exact role of mitochondria in development and disease, specifically in stem cell regulation and tumorigenesis. Such research may also reveal whether and how the endosymbiotic event that gave rise to the mitochondrion was crucial for the evolution of cell cycle regulatory mechanisms in eukaryotes that are absent in prokaryotes.
Cell death proteins: An evolutionary role in cellular adaptation before the advent of apoptosis
Authors: Dick Sarah A. , Megeney Lynn A.
Published: August 2013

Programmed cell death (PCD) or apoptosis is a broadly conserved phenomenon in metazoans, whereby activation of canonical signal pathways induces an ordered dismantling and death of a cell. Paradoxically, the constituent proteins and pathways of PCD (most notably the metacaspase/caspase protease mediated signal pathways) have been demonstrated to retain non‐death functions across all phyla including yeast, nematodes, drosophila, and mammals. The ancient conservation of both death and non‐death functions of PCD proteins raises an interesting evolutionary conundrum: was the primordial intent of these factors to induce cell death or to regulate other cellular adaptations? Here, we propose the hypothesis that apoptotic behavior of PCD proteins evolved or were co‐opted from core non‐death functions.
Quinary protein structure and the consequences of crowding in living cells: Leaving the test‐tube behind
Authors: Wirth Anna Jean , Gruebele Martin
Published: August 2013

Although the importance of weak protein‐protein interactions has been understood since the 1980s, scant attention has been paid to this “quinary structure”. The transient nature of quinary structure facilitates dynamic sub‐cellular organization through loose grouping of proteins with multiple binding partners. Despite our growing appreciation of the quinary structure paradigm in cell biology, we do not yet understand how the many forces inside the cell – the excluded volume effect, the “stickiness” of the cytoplasm, and hydrodynamic interactions – perturb the weakest functional protein interactions. We discuss the unresolved problem of how the forces in the cell modulate quinary structure, and to what extent the cell has evolved to exert control over the weakest biomolecular interactions. We conclude by highlighting the new experimental and computational tools coming on‐line for in vivo studies, which are a critical next step if we are to understand quinary structure in its native environment.
Synthesis of Symmetrical and Nonsymmetrical Bisthienylcyclopentenes
Authors: Szalóki György , Pozzo Jean‐Luc
Published: August 2013

Diarylethenes possess unique structural properties, which enabled them to find widespread applications in the field of photochromism. Nowadays, bisthienylcyclopentenes (BTCs) present the most popular subfamily of these compounds, which are widely used as P‐type chromophores. This minireview summarises the main strategies for the synthesis of symmetrical and nonsymmetrical BTCs. In addition, attention is drawn to desymmetrisations achieved by monosubstitutions, which is not frequently utilised, although it can be highly advantageous. This is supported with some of the authors’ latest results.
Graphics processing unit‐accelerated techniques for bio‐inspired computation in the primary visual cortex
Authors: Chessa Manuela , Pasquale Giulia
Published: August 2013

The spread of graphics processing unit (GPU) computing paved the way to the possibility of reaching high‐computing performances in the simulation of complex biological systems. In this work, we develop a very efficient GPU‐accelerated neural library, which can be employed in real‐world contexts. Such a library provides the neural functionalities that are the basis of a wide range of bio‐inspired models, and in particular, we show its efficacy in implementing a cortical‐like architecture for visual feature coding and estimation. In order to fully exploit the intrinsic parallelism of such neural architectures and to manage the huge amount of data that characterizes the internal representation of distributed neural models, we devise an effective algorithmic solution and an efficient data structure. In particular, we exploit both data parallelism and task parallelism, with the aim of optimally taking advantage from the computational capabilities of modern graphics cards. Moreover, we assess the performances of two different development frameworks, both supplying a wide range of basic signal processing GPU‐accelerated functions. A systematic analysis, aiming at comparing different algorithmic solutions, shows the best data structure and parallelization computational scheme to compute features from a distributed population of neural units. Copyright © 2013 John Wiley & Sons, Ltd.
Understanding the Implications of Environmental taxes: The Case of the Danish Weight Based Packaging Product Charge
Authors: Cela Enian , Kaneko Shinji
Published: August 2013

Packaging products, in particular those made from plastic, are playing an increasingly significant role in our everyday life. Because of the environmental issues associated with packaging, European countries, in particular EU member states, have long applied various policies to deal with this issue. One policy option that is rarely applied to packaging is taxation in the form of material levies or product charges. However, Denmark has applied product charges in the form of weight based tariffs since 1999. The purpose of the product charge is to stimulate a decrease in the demand for virgin packaging (packaging newly entering the market). This paper examines the effectiveness of Denmark's packaging charge, with a focus on non‐beverage plastic packaging. Applying a trade gravitation regression model incorporating import quantity as the dependent variable and a tax dummy amongst the explanatory variables, the analysis explores the effectiveness of the tax policy in reducing import demand. From a sample of 19 major exporters and an analysis covering the period between 1994 and 2007, we conclude that the product charge policy did not produce the desired effect. We conclude by suggesting that policy makers adopt a cautious approach to the adoption of environmental taxes. Copyright © 2013 John Wiley & Sons, Ltd and ERP Environment
The Green Economy: Incremental Change or Transformation?
Authors: Borel‐Saladin Jacqueline Madeleine , Turok Ivan Nicholas
Published: August 2013

The concept of the green economy presented in three reports from leading global organizations is examined in this paper. These include the United Nations Environment Programme's Towards a Green Economy, the World Bank's Inclusive Green Growth and the Organisation for Economic Co‐operation and Development's Towards Green Growth. The main critiques of the concept of the green economy are also considered. Contrary to views that the green economy merely represents ‘green‐washing’ and tweaking of the current economic system, this paper concludes that the green economy has the potential to effect substantive and transformative change towards the goal of sustainable development. Copyright © 2013 John Wiley & Sons, Ltd and ERP Environment.
Genome‐Wide Association Study of a Heart Failure Related Metabolomic Profile Among African Americans in the Atherosclerosis Risk in Communities (ARIC) Study
Authors: Yu Bing , Zheng Yan , Alexander Danny , Manolio Teri A. , Alonso Alvaro , Nettleton Jennifer A. , Boerwinkle Eric
Published: August 2013

Both the prevalence and incidence of heart failure (HF) are increasing, especially among African Americans, but no large‐scale, genome‐wide association study (GWAS) of HF‐related metabolites has been reported. We sought to identify novel genetic variants that are associated with metabolites previously reported to relate to HF incidence. GWASs of three metabolites identified previously as risk factors for incident HF (pyroglutamine, dihydroxy docosatrienoic acid, and X‐11787, being either hydroxy‐leucine or hydroxy‐isoleucine) were performed in 1,260 African Americans free of HF at the baseline examination of the Atherosclerosis Risk in Communities (ARIC) study. A significant association on chromosome 5q33 (rs10463316, MAF = 0.358, P‐value = 1.92 × 10−10) was identified for pyroglutamine. One region on chromosome 2p13 contained a nonsynonymous substitution in N‐acetyltransferase 8 (NAT8) was associated with X‐11787 (rs13538, MAF = 0.481, P‐value = 1.71 × 10−23). The smallest P‐value for dihydroxy docosatrienoic acid was rs4006531 on chromosome 8q24 (MAF = 0.400, P‐value = 6.98 × 10−7). None of the above SNPs were individually associated with incident HF, but a genetic risk score (GRS) created by summing the most significant risk alleles from each metabolite detected 11% greater risk of HF per allele. In summary, we identified three loci associated with previously reported HF‐related metabolites. Further use of metabolomics technology will facilitate replication of these findings in independent samples.
Characterizing borehole fluid flow and formation permeability in the ocean crust using linked analytic models and Markov chain Monte Carlo analysis
Authors: Winslow D. M. , Fisher A. T. , Becker K.
Published: August 2013

Thermal records from boreholes in young oceanic crust, in which water is flowing up or down, are used to assess formation and borehole flow properties using three analytic equations that describe the transient thermal and barometric influence of downhole or uphole flow. We link these calculations with an iterative model and apply Markov chain Monte Carlo (MCMC) analysis to quantify ranges of possible values. The model is applied to two data sets interpreted in previous studies, from Deep Sea Drilling Project Hole 504B on the southern flank of the Costa Rica Rift and Ocean Drilling Program Hole 1026B on the eastern flank of the Juan de Fuca Ridge, and to two new records collected in Integrated Ocean Drilling Program Holes U1301A and U1301B, also on the eastern flank of the Juan de Fuca Ridge. Our calculations indicate that fluid flow rates when thermal logs were collected were ∼2 L/s in Holes 504B, 1026B, and U1301A, and >20 L/s in Hole U1301B. The median bulk permeabilities determined with MCMC analyses are 4 to 7 × 10−12 m2 around the uppermost parts of Holes 504B, 1026B, and U1301A, and 1.5 × 10−11 m2 around a deeper section of Hole U1301B, with a standard deviation of 0.2 to 0.3 log cycles at each borehole. The consistency of permeability values inferred from these four holes is surprising, given the range of values determined globally and the tendency for permeability to be highly variable in fractured crystalline rock formations such as the upper oceanic crust.
Evidence for weak ferromagnetic moment within the basal plane of hematite natural crystals at low temperature
Authors: Martin‐Hernandez Fatima , Hirt Ann M.
Published: August 2013

Low‐temperature magnetization of hematite within the basal plane has been studied in a collection of natural crystals by means of torque magnetometry. Comparison between the torque curves at room temperature and at 77 K allows identification of a weak ferromagnetic moment constrained within the basal plane at temperatures well below the Morin transition. Annealing the samples produces the expected reduction of the weak ferromagnetic moment, but there is also a relationship between the ferromagnetic moment before and after annealing. Low‐temperature measurements after the annealing experiment reveal the presence of a weak ferromagnetic moment that survives the annealing. This observation suggests the magnetic structure of natural hematite crystals below the Morin transition can still be a carrier of magnetization.
A chronic oral reference dose for hexavalent chromium‐induced intestinal cancer
Authors: Thompson Chad M. , Kirman Christopher R. , Proctor Deborah M. , Haws Laurie C. , Suh Mina , Hays Sean M. , Hixon J. Gregory , Harris Mark A.
Published: August 2013

High concentrations of hexavalent chromium [Cr(VI)] in drinking water induce villous cytotoxicity and compensatory crypt hyperplasia in the small intestines of mice (but not rats). Lifetime exposure to such cytotoxic concentrations increases intestinal neoplasms in mice, suggesting that the mode of action for Cr(VI)‐induced intestinal tumors involves chronic wounding and compensatory cell proliferation of the intestine. Therefore, we developed a chronic oral reference dose (RfD) designed to be protective of intestinal damage and thus intestinal cancer. A physiologically based pharmacokinetic model for chromium in mice was used to estimate the amount of Cr(VI) entering each intestinal tissue section (duodenum, jejunum and ileum) from the lumen per day (normalized to intestinal tissue weight). These internal dose metrics, together with corresponding incidences for diffuse hyperplasia, were used to derive points of departure using benchmark dose modeling and constrained nonlinear regression. Both modeling techniques resulted in similar points of departure, which were subsequently converted to human equivalent doses using a human physiologically based pharmacokinetic model. Applying appropriate uncertainty factors, an RfD of 0.006 mg kg–1 day–1 was derived for diffuse hyperplasia—an effect that precedes tumor formation. This RfD is protective of both noncancer and cancer effects in the small intestine and corresponds to a safe drinking water equivalent level of 210 µg l–1. This concentration is higher than the current federal maximum contaminant level for total Cr (100 µg l–1) and well above levels of Cr(VI) in US drinking water supplies (typically ≤ 5 µg l–1). © 2013 The Authors. Journal of Applied Toxicology published by John Wiley & Sons, Ltd.
Effect of plasma components on the stability and permeability of microcapsule
Authors: Chen Li , Zhang Ying , Li Shen , Wang Xiuli , Li Na , Wang Yu , Guo Xin , Zhao Shan , Yu Weiting , Sun Guangwei , Liu Yang , Ma Xiaojun
Published: August 2013

Immobilization of hepatocytes in microcapsules has been a potentially alternative methodology for bioartificial livers (BALs). Moreover, the stability and permeability are the key parameters of these microcapsules. However, these alginate‐based microcapsules are unstable if the surrounding medium disrupts the ionic interactions between alginate and the polycation. As hundreds of components are included in human plasma, the stability and permeability in plasma of microcapsules need to be sufficiently investigated. In the present study, the stability of three kinds of alginate‐based microcapsules was evaluated when they were immersed in plasma. Our results showed that stability of alginate‐α‐poly (l‐lysine)‐alginate (α‐APA) microcapsules was well maintained, better than those of alginate‐ε‐poly (l‐lysine)‐alginate (ε‐APA) and alginate–chitosan–alginate (ACA) microcapsules. Also, factors affecting the stability of microcapsules in plasma were analyzed and it showed that heparin was the key factor that affected the stability of α‐APA microcapsules, whereas heparin and low molecular electrolytes such as HCO3− and H2PO4−/HPO42− were the factors to ε‐APA and ACA microcapsules. In addition, the permeability evaluation showed no decrease in permeability of microcapsules after incubation in plasma. Our study might provide a foundation for the selection and modification of materials for microcapsule‐based BAL devices. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 2408–2416, 2014.
Preparation, characterization, release kinetics, and in vitro cytotoxicity of calcium silicate cement as a risedronate delivery system
Authors: Gong Tianxing , Wang Zhiqin , Zhang Yubiao , Sun Changshan , Yang Quanzu , Troczynski Tom , Häfeli Urs O.
Published: August 2013

Injectable bone cements have been well characterized and studied in non‐load bearing bone fixation and bone screw augmentation applications. Current calcium phosphate cement or poly(methyl methacrylate) cement have drawbacks like low mechanical strength and in situ exothermic properties. This leads especially in patients with osteoporosis to worsening contact between implant and bone and can finally lead to implant failure. To improve these properties, a calcium silicate cement (CSC) was prepared, which additionally contained the bisphosphonate risedronate (RA) to promote osteoblast function. Cement setting rate and compressive strength were measured and found to be reduced by RA above 0.5 wt%. X‐ray diffraction, Rietveld refinement analysis, scanning electron microscopy, and porosity measurements by gas sorption revealed that RA reduces calcium silicate hydrate gel formation and changes the cement's microstructure. Cumulative release profiles of RA from CSC up to 6 months into phosphate buffer solution were analyzed by high‐performance liquid chromatography, and the results were compared with theoretical release curves obtained from the Higuchi equation. Fourier transform infrared spectra measurements and drug release studies indicate that calcium–RA formed within the cement, from which the drug can be slowly released over time. An investigation of the cytotoxicity of the RA‐CSC systems upon osteoblast‐like cells showed no toxic effects of concentrations up to 2%. The delivery of RA from within a CSC might thus be a valuable and biocompatible new approach to locally deliver RA and to reconstruct and/or repair osteoporosis‐related bone fractures. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 2295–2304, 2014.
The use of new surface‐modified poly(2‐hydroxyethyl methacrylate) hydrogels in tissue engineering: Treatment of the surface with fibronectin subunits versus Ac‐CGGASIKVAVS‐OH, cysteine, and 2‐mercaptoethanol modification
Authors: Kubinová Šárka , Horák Daniel , Vaněček Václav , Plichta Zdeněk , Proks Vladimír , Syková Eva
Published: August 2013

Superporous poly(2‐hydroxyethyl methacrylate) is successfully used as a scaffold material for tissue engineering; however, it lacks functional groups that support cell adhesion. The objective of this study was to investigate the cell‐adhesive properties of biomimetic ligands, such as laminin‐derived Ac‐CGGASIKVAVS‐OH (SIKVAV) peptide and fibronectin subunits (Fn), as well as small molecules exemplified by 2‐mercaptoethanol (ME) and cysteine (Cys), immobilized on a copolymer of 2‐hydroxyethyl methacrylate (HEMA) with 2‐aminoethyl methacrylate (AEMA) by a maleimide‐thiol coupling reaction. The maleimide group was introduced to the P(HEMA‐AEMA) hydrogels by the reaction of their amino groups with N‐γ‐maleimidobutyryl‐oxysuccinimide ester (GMBS). Mesenchymal stem cells (MSCs) were used to investigate the cell adhesive properties of the modified hydrogels. A significantly larger area of cell growth as well as a higher cell density were found on Fn‐ and SIKVAV‐modified hydrogels when compared to the ME‐ and Cys‐modified supports or neat P(HEMA‐AEMA). Moreover, Fn‐modification strongly stimulated cell proliferation. The ability of MSCs to differentiate into adipocytes and osteoblasts was maintained on both Fn‐ and SIKVAV‐modifications, but it was reduced on ME‐modified hydrogels and neat P(HEMA‐AEMA). The results show that the immobilization of SIKVAV and Fn‐subunits onto superporous P(HEMA‐AEMA) hydrogels via a GMBS coupling reaction improves cell adhesive properties. The high proliferative activity observed on Fn‐modified hydrogels suggests that the immobilized Fn‐subunits maintain their bioactivity and thus represent a promising tool for application in tissue engineering. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 2315–2323, 2014.
The effect of active ingredient‐containing chitosan/polycaprolactone nonwoven mat on wound healing: In vitro and in vivo studies
Authors: Bai Meng‐Yi , Chou Tz‐Chong , Tsai Jie‐Chang , Yu Wen‐Chun
Published: August 2013

The use of an electrospun polycaprolactone (PCL) nonwoven mat that is coated with a layer of chitosan (CS) containing active ingredient [tea tree oil (TTO)] represents an effective strategy for producing functional dressings. CS‐coated porous PCL nonwoven mat (CS3/PCLNM) with various concentrations of active ingredients were produced and investigated. In vitro, active ingredient‐containing CS3/PCLNM is effective in inhibiting the formation of nitrite and the growth of Staphylococcus aureus. Both active ingredient TTO and CS have been proven to reach their maximum amount of releases within 24 h of contact with water‐based environment. In vivo, full‐thickness skin removal (1.2 cm × 1.2 cm) was performed on the back of the C57BL6/J mice in noninfected and infected animal models. Four groups of functional dressings were tested in this work including Tegderm™, PCLNM, CS3/PCLNM, and 100 μL TTO‐CS3/PCLNM. After 7 days post‐treatment, the bacterial levels were found to be significantly lower in both CS3/PCLNM and 100 μL TTO‐CS3/PCLNM‐treated groups than in the control group (81.6 ± 18.1% and 93.7 ± 9.57% of reductions in the bacterial load in the pus relative to the control group, respectively). Additionally, based on the histological analyses, the 100 μL TTO‐CS3/PCLNM‐treated group outperformed all other groups in wound healing. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 2324–2333, 2014.
A 3‐D numerical study of the thermal evolution of the Moon after cumulate mantle overturn: The importance of rheology and core solidification
Authors: Zhang Nan , Parmentier E. M. , Liang Yan
Published: August 2013

Models in which the mantle of the Moon evolves from an initially stratified state following magma ocean solidification and overturn have been applied to address important features of long‐term thermal evolution of the Moon, including convective instability of overturned ilmenite‐bearing cumulates (IBC) at the lunar core‐mantle boundary, generation of mare basalts, core sulfur content and inner core radius, paleomagnetism, and the present‐day mantle structure. Whether a dense overturned IBC‐rich layer at the bottom of the mantle can become thermally unstable to generate a single upwelling is controlled largely by the temperature‐dependence of viscosity (the activation energy). Convective instability of the IBC‐rich layer controls the heat flux out the core and the presence of an internally generated magnetic field. A long period of (~700 Ma) high positive core‐mantle‐boundary (CMB) heat flux after the instability of the IBC‐rich layer is expected from our models. Present‐day deep mantle temperatures inferred from seismic and gravitational inversion constrain the magnitude of mantle viscosity from 5 × 1019 to 1 × 1021 Pa s. The CMB temperature and solidified inner core radius inferred from seismic reflection constrain the core sulfur content. Our evolution models with 5–10 wt % sulfur content can produce the observed 240 km radius inner core at the present day. The asymmetrical distribution of the deep moonquakes only in the nearside mantle could be explained as the remnant structure of the single chemical upwelling generated from IBC‐rich layer. Our evolution model after the overturn results in an early ~0.55 km expansion in radius for ~1000 Ma due to the radiogenic heating associated with IBC in the deep mantle and may provide a simple explanation for the early expansion inferred from the Gravity Recovery and Interior Laboratory mission.
Is type 2 diabetes mellitus associated with alterations in hearing? A systematic review and meta‐analysis
Authors: Akinpelu Olubunmi V. , Mujica‐Mota Mario , Daniel Sam J.
Published: August 2013

Objectives/Hypothesis

The aim of this study was to systematically and quantitatively review the available evidence on the effects of type 2 diabetes mellitus on hearing function.

Data Sources and Review Methods

Eligible studies were identified through searches of eight different electronic databases and manual searching of references. Articles obtained were independently reviewed by two authors using predefined inclusion criteria to identify eligible studies. Meta‐analysis was performed on pooled data using Cochrane's Review Manager.

Results

Eighteen articles fulfilled the inclusion criteria. Hearing loss (HL) was defined by all studies as pure tone average greater than 25dB in the worse ear. The incidence of HL ranged between 44% and 69.7% for type 2 diabetics, significantly higher than in controls (OR 1.91; 95% confidence interval 1.47–2.49). The mean PTA (pure tone audiometry) thresholds were greater in diabetics than in controls for all frequencies [test or overall effect Z = 3.68, P = 0.0002]. Auditory brainstem response (ABR) wave V latencies were also statistically significantly longer in diabetics when compared to control groups [OR 3.09, 95% CI 1.82– 4.37, P < 0.00001].

Conclusions

Type 2 diabetic patients had significantly higher incidence for at least the mild degree of HL when compared with controls. Mean PTA thresholds were greater in diabetics for all frequencies but were more clinically relevant at 6000 and 8000 Hz. Prolonged ABR wave V latencies in the diabetic group suggest retro‐cochlear involvement. Age and duration of DM play important roles in the occurrence of DM‐related HL.

Level of Evidence

3a. Laryngoscope, 124:767–776, 2014
Antiplatelet and anticoagulation therapy in microlaryngeal surgery
Authors: Francis David O. , Dang Jennifer H. , Fritz Mark A. , Garrett C. Gaelyn
Published: August 2013

Objectives/Hypothesis

Indications for antiplatelet and anticoagulation use are expanding. There is no evidence to direct therapeutic management in patients undergoing microlaryngeal surgeries. Our aim was to compare bleeding complications between microlaryngeal surgeries performed for patients preoperatively taken off and maintained on antiplatelet and/or anticoagulation therapy.

Study Design

Retrospective cohort study.

Methods

Patients undergoing microlaryngeal surgeries (2008–2009) on baseline antiplatelet and/or anticoagulation therapy were identified. Records were reviewed to determine whether therapy was stopped preoperatively. The primary outcome, bleeding complication, was compared between those taken off and maintained on therapy. Patient characteristics, surgical data, and outcomes were assessed.

Results

Of 287 microlaryngeal surgeries, 26% were performed for patients on antiplatelet (23%) and/or anticoagulation (3%) therapy. There was no difference in bleeding complications between patients' naïve to and on baseline antiplatelet or anticoagulation therapy [naïve: 3.8% vs. on: 5.3%, P = 0.58] and no thromboembolic events. Among surgeries performed for patients on baseline antiplatelet therapy, 35% preoperatively stopped therapy. No observed difference in bleeding complications was observed between those taken off or maintained on therapy [off: 8.0% vs. on: 4.9%, P = 0.63]. Of 3% of surgeries performed for patients on warfarin, no bleeding complications occurred, even among the 8/10 with therapeutic international normalized ratios.

Conclusions

Perioperative management decisions regarding antiplatelet and anticoagulation therapy are becoming more common. Results suggest that antiplatelet therapy can be maintained during microlaryngeal surgery without increasing bleeding risk. Further prospective research is required to confirm findings and rigorously investigate the safety of continuing warfarin and other anticoagulation therapy in these surgeries.

Level of Evidence

4. Laryngoscope, 124:928–934, 2014
Duplicated facial nerve trunk with a first branchial cleft cyst
Authors: Hinson Drew , Poteet Perry , Bower Charles
Published: August 2013

Objectives/Hypothesis

First branchial cleft anomalies are rare and their various anatomical relationships to the facial nerve have been described. We encountered a 15‐year‐old female with a type II first branchial cleft cyst presenting as a right neck mass that we found during surgical excision to transverse two main facial nerve trunks. To our knowledge, this is the first reported case of a first branchial cleft anomaly in conjunction with a duplicated facial nerve trunk.Laryngoscope, 124:662–664, 2014
Changing indications for maxillomandibular reconstruction with osseous free flaps: A 17‐year experience with 620 consecutive cases at UCLA and the impact of osteoradionecrosis
Authors: Zaghi Soroush , Danesh Jennifer , Hendizadeh Leenoy , Nabili Vishad , Blackwell Keith E.
Published: August 2013

Objectives/Hypothesis

To characterize the changing indications for osseous free flaps in maxillomandibular reconstruction at our institution.

Study Design

Retrospective chart review.

Methods

Database review of patients who underwent free‐flap reconstruction of the jaws using vascularized bone‐containing free tissue transfer from 1995 to 2012 at the University of California Los Angeles (UCLA).

Results

A total of 620 osseous free flaps were performed. The most common indications for surgery were squamous cell carcinoma (n = 442) and osteoradionecrosis (ORN)) of the mandible (n = 73). There were no significant differences in 90‐day perioperative complication, flap viability, or mortality rates between any of the indications for surgery. Patients older than 60 years had a higher rate of major perioperative complication (P = 0.0028). ORN cases represented 1.3% ± 1.2% of surgical volume from 1995 to 2000, 8.7% ± 1.8% from 2001 to 2006, and 17.5% ± 2.2% from 2007 to 2012 (P <0.0001). Among cases of ORN, 95.8% of patients had radiation therapy completed at centers outside of our hospital system. For patients with ORN, there was an average interval of 8.7 ± 8.0 years from initiation of radiotherapy to the date of mandibulectomy (range 1–37 years).

Conclusion

The incidence of ORN as an indication for free‐flap reconstruction has increased at our institution in recent years. This may reflect an increasing need for the surgical management of medically refractory ORN, a rising awareness or prevalence of ORN overall, and/or increasing comfort with free flaps as a treatment for ORN. Patients who undergo free‐flap surgery for ORN do not have greater risks of 90‐day perioperative complications or differences in free‐flap viability as compared to patients who undergo free‐flap reconstruction for other indications.

Level of Evidence

2b. Laryngoscope, 124:1329–1335, 2014
Effect of Ritonavir‐Boosted Danoprevir, a Potent Hepatitis C Virus Protease Inhibitor, on the Pharmacokinetics of Methadone in Healthy Subjects Undergoing Methadone Maintenance Therapy
Authors: Moreira Sebastian A. , Morcos Peter N. , Navarro Mercidita T. , Bech Nuria , Smith Patrick F. , Brennan Barbara J.
Published: August 2013

Study Objective

To investigate the steady‐state pharmacokinetics of methadone when coadministered with ritonavir‐boosted danoprevir (DNVr).

Design

Open‐label, two‐period, single‐sequence pharmacokinetic study.

Setting

Two U.S. research centers.

Patients

Eighteen methadone‐maintained healthy adults.

Measurements and Main Results

In Period 1 (Day −1), subjects received their daily methadone maintenance therapy (MMT). In Period 2 (Days 1–10), subjects received MMT plus DNVr 100/100 mg twice/day. Pharmacokinetic parameters for the total concentrations of (R)‐ and (S)‐methadone on Days −1 and 10 were determined using noncompartmental methods. Unbound (R)‐ and (S)‐methadone concentrations at 3 hours postdose were also assessed on Days −1 and 10. Geometric mean ratios (GMRs) and 90% confidence intervals (CIs) were used to compare steady‐state (R)‐ and (S)‐methadone pharmacokinetics when MMT was administered with or without DNVr. Methadone withdrawal was assessed using the Subjective Opiate Withdrawal Scale. Compared with MMT alone, methadone AUCtau and Cmax GMR (90% CI) following coadministration with DNVr were 1.02 (0.91–1.15) and 1.01 (0.90–1.13) for (R)‐methadone, and 1.01 (0.90–1.13) and 0.99 (0.89–1.10) for (S)‐methadone, respectively. Unbound (R‐ and (S)‐methadone concentrations were comparable with or without DNVr. No instances of methadone withdrawal were reported. MMT in combination with DNVr was well tolerated.

Conclusion

Coadministration of DNVr with MMT resulted in no significant pharmacokinetic interactions or signs of methadone withdrawal. No dosage adjustment is needed for MMT when coadministered with DNVr.