bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect and Mechanism of Association of 8‐Hydroxy‐1,3,6‐pyrenetrisulfonic Acid to Chitosan: Physicochemical Properties of the Complex
Authors: Barnadas‐Rodríguez Ramon
Published: November 2012

The interaction of 8‐hydroxy‐1,3,6‐pyrenetrisulfonic acid (HPTS) with chitosan (CS) is investigated by studying the changes that HPTS produces on the properties of CS. HPTS specifically binds to the free amino groups of CS modifying its zeta potential, isoelectric point, water solubility, aggregation state, and the viscosity of the solutions. The association of HPTS to CS is a positive cooperative process described by the Hill equation. In a first stage, HPTS causes a screening that parallels the one caused by NaCl. A subsequent increase of the HPTS concentration results in conformational changes of CS favoring the union of the HPTS and a massive CS aggregation. These facts, not observed in the presence of NaCl, cannot be explained merely by an electrostatic screening effect caused by HPTS and a cross‐linking mechanism is suggested.
Photo‐Responsive Polymeric Structures Based on Spiropyran
Authors: Florea Larisa , Diamond Dermot , Benito‐Lopez Fernando
Published: November 2012

Spiropyrans are one of the most popular classes of photochromic compounds that change their optical and structural properties in response to external inputs such as light, protons and metal ions, making them ideal molecules for the fabrication of multifunctional stimuli‐responsive materials. Nowadays, the emphasis in polymeric materials incorporating spiropyran units focuses on the effectiveness of their reversible response to external photonic stimuli. Photo‐control of a range of key characteristics for flow systems, such as wettability, permeability, photo‐modulation of flow by photo‐actuation of valves, photonic control of uptake and release of guests using films and coatings, and colorimetric sensing of various species, are highlighted and discussed.

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Association of VEGF and KDR single nucleotide polymorphisms with colorectal cancer susceptibility in Koreans
Authors: Jang Moon Ju , Jeon Young Joo , Kim Jong Woo , Cho Yun Kyung , Lee Seung Ku , Hwang Seong Gyu , Oh Doyeun , Kim Nam Keun
Published: November 2012

Vascular endothelial growth factor (VEGF) and its receptor kinase insert domain‐containing receptor (KDR) play crucial roles in angiogenesis, which contributes to the development and progression of solid tumors. The aim of this study was to investigate the associations of VEGF (−2578C > A, −1154G > A, −634G > C, and 936C > T) and KDR (−604T > C and 1192G > A) polymorphisms with the development of colorectal cancer (CRC). A total of 882 participants (390 CRC patients and 492 controls) were enrolled in the study. The genotyping of VEGF and KDR polymorphisms was performed by polymerase chain reaction–restriction fragment length polymorphism assay. We found that the CT and TT genotype of the 936C > T was associated with an increased risk of CRC compared with the CC genotype as the dominant model for the T allele. In addition, we also found a increased CRC risk with TC + CC genotype of KDR −604T > C compared with TT genotype in CRC patients and control subjects. Similarly, KDR 1192G > A also showed significant association between 1192G > A variants and risk of CRC. In the haplotype analyses, haplotype −2578A/−1154A/−634G/936T of VEGF polymorphisms and haplotype −604C/1192G and −604C/1192A of KDR polymorphisms were associated with an increased susceptibility of CRC. Our results suggest that the VEGF 936C > T, KDR −604T > C, and KDR 1192G > A polymorphisms may be contribute to CRC risk in the Korean population. © 2012 Wiley Periodicals, Inc.
Multislice cardiac arterial spin labeling using improved myocardial perfusion quantification with simultaneously measured blood pool input function
Authors: Campbell‐Washburn Adrienne E. , Zhang Hui , Siow Bernard M. , Price Anthony N. , Lythgoe Mark F. , Ordidge Roger J. , Thomas David L.
Published: November 2012

Purpose

Myocardial blood flow (MBF) is an important indicator of cardiac tissue health, which can be measured using arterial spin labeling. This study aimed to develop a new method of MBF quantification with blood pool magnetization measurement (“bpMBF quantification”) that allows multislice cardiac arterial spin labeling.

Theory and Methods

A multislice segmented ECG‐gated Look‐Locker T1 mapping sequence was validated. Quantification of multislice arterial spin labeling is not straightforward due to the large volume of blood inverted following slice‐selective inversion. For bpMBF quantification, a direct measurement of the left‐ventricle blood pool magnetization was used to approximate the blood input function into the Bloch equations. Simulations and in vivo measurements in the mouse heart were performed to evaluate the bpMBF method.

Results

Measurements indicated that blood pool magnetization requires ∼3 s to return to equilibrium following slice‐selective inversion. Simulation and in vivo results show that bpMBF quantification is robust to variations in slice‐selective thickness and therefore applicable to multislice acquisition, whereas traditional methods are likely to underestimate multislice perfusion. In vivo, single and multislice perfusion values matched well when quantified using bpMBF.

Conclusion

The first multislice cardiac arterial spin labeling technique has been presented, which can be used for accurate perfusion measurements in studies of cardiac disease. Magn Reson Med, 70:1125–1136, 2013. © 2012 Wiley Periodicals, Inc.
Hematocrit and oxygenation dependence of blood 1H2O T1 at 7 tesla
Authors: Grgac Ksenija , van Zijl Peter C. M. , Qin Qin
Published: November 2012

Knowledge of blood 1H2O T1 is critical for perfusion‐based quantification experiments such as arterial spin labeling and cerebral blood volume‐weighted MRI using vascular space occupancy. The dependence of blood 1H2O T1 on hematocrit fraction (Hct) and oxygen saturation fraction (Y) was determined at 7 T using in vitro bovine blood in a circulating system under physiological conditions. Blood 1H2O R1 values for different conditions could be readily fitted using a two‐compartment (erythrocyte and plasma) model, which are described by a monoexponential longitudinal relaxation rate constant dependence. It was found that T1 = 2171 ± 39 ms for Y = 1 (arterial blood) and 2010 ± 41 ms for Y = 0.6 (venous blood), for a typical Hct of 0.42. The blood 1H2O T1 values in the normal physiological range (Hct from 0.35 to 0.45, and Y from 0.6 to 1.0) were determined to range from 1900 to 2300 ms. The influence of oxygen partial pressure (pO2) and the effect of plasma osmolality for different anticoagulants were also investigated. It is discussed why blood 1H2O T1 values measured in vivo for human blood may be about 10–20% larger than found in vitro for bovine blood at the same field strength. Magn Reson Med, 70:1153–1159, 2013. © 2012 Wiley Periodicals, Inc.
Regional specificity of manganese accumulation and clearance in the mouse brain: implications for manganese‐enhanced MRI
Authors: Grünecker B. , Kaltwasser S. F. , Zappe A. C. , Bedenk B. T. , Bicker Y. , Spoormaker V. I. , Wotjak C. T. , Czisch M.
Published: November 2012

Manganese‐enhanced MRI has recently become a valuable tool for the assessment of in vivo functional cerebral activity in animal models. As a result of the toxicity of manganese at higher dosages, fractionated application schemes have been proposed to reduce the toxic side effects by using lower concentrations per injection. Here, we present data on regional‐specific manganese accumulation during a fractionated application scheme over 8 days of 30 mg/kg MnCl2, as well as on the clearance of manganese chloride over the course of several weeks after the termination of the whole application protocol supplying an accumulative dose of 240 mg/kg MnCl2. Our data show most rapid accumulation in the superior and inferior colliculi, amygdala, bed nucleus of the stria terminalis, cornu ammonis of the hippocampus and globus pallidus. The data suggest that no ceiling effects occur in any region using the proposed application protocol. Therefore, a comparison of basal neuronal activity differences in different animal groups based on locally specific manganese accumulation is possible using fractionated application. Half‐life times of manganese clearance varied between 5 and 7 days, and were longest in the periaqueductal gray, amygdala and entorhinal cortex. As the hippocampal formation shows one of the highest T1‐weighted signal intensities after manganese application, and manganese‐induced memory impairment has been suggested, we assessed hippocampus‐dependent learning as well as possible manganese‐induced atrophy of the hippocampal volume. No interference of manganese application on learning was detected after 4 days of Mn2+ application or 2 weeks after the application protocol. In addition, no volumetric changes induced by manganese application were found for the hippocampus at any of the measured time points. For longitudinal measurements (i.e. repeated manganese applications), a minimum of at least 8 weeks should be considered using the proposed protocol to allow for sufficient clearance of the paramagnetic ion from cerebral tissue. Copyright © 2012 John Wiley & Sons, Ltd.
Secondary mutations in BRCA2 associated with clinical resistance to a PARP inhibitor
Authors: Barber Louise J , Sandhu Shahneen , Chen Lina , Campbell James , Kozarewa Iwanka , Fenwick Kerry , Assiotis Ioannis , Rodrigues Daniel Nava , Reis-Filho Jorge S , Moreno Victor , Mateo Joaquin , Molife L Rhoda , De Bono Johann , Kaye Stan , Lord Christopher J , Ashworth Alan
Published: November 2012

PARP inhibitors (PARPi) for the treatment of BRCA1 or BRCA2 deficient tumours are currently the focus of seminal clinical trials exploiting the concept of synthetic lethality. Although clinical resistance to PARPi has been described, the mechanism underlying this has not been elucidated. Here, we investigate tumour material from patients who had developed resistance to the PARPi olaparib, subsequent to showing an initial clinical response. Massively parallel DNA sequencing of treatment‐naive and post‐olaparib treatment biopsies identified tumour‐specific BRCA2 secondary mutations in olaparib‐resistant metastases. These secondary mutations restored full‐length BRCA2 protein, and most likely cause olaparib resistance by re‐establishing BRCA2 function in the tumour cells. Copyright © 2012 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Three‐dimensional ultrasound and maternal bonding, a third trimester study and a review
Authors: de Jong‐Pleij E. A. P. , Ribbert L. S. M. , Pistorius L. R. , Tromp E. , Mulder E. J. H. , Bilardo C. M.
Published: November 2012

Objective

To compare the effect of third trimester three‐dimensional and four‐dimensional (3D/4D) versus two‐dimensional (2D) ultrasound (US) of the fetal face on maternal bonding. Studies quantifying the psychological effect of 3D/4D US on mothers, pregnant of a fetus with no detectable abnormalities, were reviewed.

Methods

One hundred sixty Caucasian women attended a third trimester 3D/4D or 2D US examination. Women filled out the Maternal Antenatal Attachment Scale (MAAS) 1 to 2 weeks before (MAAS1) and 1 to 2 weeks after (MAAS2) the US examination. Visibility, recognition and attractiveness were assessed.

Results

Within both US groups, the MAAS2 scores were significantly higher than the MAAS1 scores (p < 0.0001). No differences in MAAS scores between the US groups emerged. Visibility and recognition were significantly positively related with the increase in MAAS scores (p = 0.003 and p = 0.042) in the 3D/4D group.

Of 13 psychological studies, eight studies evaluated bonding and found no difference between 3D/4D and 2D US. The effect of 3D/4D US on satisfaction or perception showed conflicting results, and on anxiety/stress, reduction was the same as after 2D US.

Conclusions

Bonding increases after either a 3D/4D or 2D US. The effect of 3D/4D US on bonding is stronger at better degrees of visibility and recognition. © 2012 John Wiley & Sons, Ltd.
Abnormal infant pulmonary function in young children with neuroendocrine cell hyperplasia of infancy
Authors: Kerby Gwendolyn S. , Wagner Brandie D. , Popler Jonathan , Hay Thomas C. , Kopecky Carol , Wilcox Stephanie L. , Quinones Ralph R. , Giller Roger H. , Accurso Frank J. , Deterding Robin R.
Published: November 2012

Rationale

Lung function in children with neuroendocrine cell hyperplasia of infancy (NEHI) and correlations with future clinical outcomes are needed to guide clinical management.

Objective

To compare results of infant pulmonary function tests (IPFTs) in children with NEHI to disease control (DC) subjects and to correlate NEHI IPFTs with future outcomes.

Methods

We performed a retrospective, single center study of IPFT in subjects diagnosed by lung biopsy (NEHI) or clinically (NEHI syndrome) and in DC subjects evaluated for cancer or pre‐hematopoietic stem cell transplantation (HSCT). Raised volume rapid thoracoabdominal compression (RVRTC) and plethysmography were performed on all infants and evaluated for quality. Standard spirometry measures, room air oxygen saturations (RA O2 sat), and weight percentiles were collected during follow up.

Measurements and Main Results

Fifty‐seven IPFTs were performed in 15 NEHI, 22 NEHI syndrome, and 20 DC subjects. RVRTC and FRC measurements were obtained in 85% or more of subjects in all groups. Significant airflow limitation (FEV0.5 P‐value ≤ 0.01) and air trapping (FRC P‐value ≤ 0.01) were seen in NEHI and NEHI syndrome subjects compared to DCs. No significant correlations were found between IPFT, oxygen use, RA O2 sat, and weight at the time of the IPFTs. Initial FEV0.5 and FRC z‐scores correlated with RA O2 sat (r = 0.60 and −0.49) at short‐term follow up (6–12 months). Most measurements of RVRTC correlated with FEV1 (n = 5) measured 4–5 years later (r > 0.50).

Conclusions

IPFTs in NEHI subjects are feasible, demonstrate significant obstruction and air trapping, and correlate with future RA O2 sat and FEV1. IPFTs may provide valuable clinical information when caring for NEHI patients. Pediatr Pulmonol. 2013; 48:1008–1015. © 2012 Wiley Periodicals, Inc.
Short‐term and Long‐term Effects of Electrical Stimulation on Skin Properties
Authors: Almalty Abdul‐Majeed R. , Hamed Saja H. , Al‐Dabbak Fuad M. , Shallan Amjad E.
Published: November 2012

Background

Electrical stimulation (ES) has been used in treating different medical conditions; however, not much is known about the effect of this application on skin properties. The purpose of this study was to investigate the short‐term and long‐term effects of ES on biophysical properties of the skin.

Methods

A pretest–posttest control design was used in the study. Thirteen men (N = 13, age (M ± SD), 19 ± 5.6 years) were free of skin abnormality on the volar aspect of both forearms. Four areas were allocated and marked with a layout template of two circles 2 cm in diameter and 2 cm apart. Areas 1 and 2 were allocated on the experimental forearm and area 3 and 4 on the control forearm. ES was applied for 15 minutes with two rubber electrodes 8 cm apart surrounding areas 1 and 2 on the experimental forearm three times a week for 2 weeks. Skin properties including transepidermal water loss (TEWL), melanin content, erythema, elasticity and pH were measured pre‐ES, during ES and post‐ES, and after 2 weeks of applying ES to find out the short‐term and long‐term effects on skin.

Results

The TEWL was increased during ES at 7, 15 and 15‐minutes post‐ES compared with the baseline (p < 0.01) and to the control forearm (p = 0.04) measurements, and no increase have been noticed of TEWL on the control forearm (p = 0.11). Also, we found no difference in the other skin properties (p > 0.05) on both forearms, and there were no long‐term effects (p > 0.05) in any tested variable.

Conclusion

Electrical stimulation caused temporary increase in TEWL with no effects on other skin properties. Copyright © 2012 John Wiley & Sons, Ltd.
The mediating role of interpersonal competence between adolescents' empathy and friendship quality: A dyadic approach
Authors: Chow Chong Man , Ruhl Holly , Buhrmester Duane
Published: November 2012

The current study examined the effect of empathy on friendship quality in the context of dyadic same‐sex friendships, and how such an effect might be mediated by interpersonal competence. A special version of the actor–partner interdependence model (APIM) was used to examine this hypothesis in 146 same‐sex friend dyads in 10th grade. Results showed that empathy was positively related to intimacy and conflict management competences. Also, adolescents higher in intimacy and conflict management competences had more friendship closeness and less discord, respectively, as perceived by both members. Consistent with our hypothesis, the relationship between empathy and self‐ and friend‐reports of friendship closeness and discord were mediated by adolescents' intimacy and conflict management competence, respectively. These findings emphasize the importance of empathy and interpersonal competence in adolescent friendships, and of considering the interdependence of these constructs in friend dyads.
Principles of Exercise Physiology: Responses to Acute Exercise and Long‐term Adaptations to Training
Authors: Rivera‐Brown Anita M. , Frontera Walter R.
Published: November 2012

Physical activity and fitness are associated with a lower prevalence of chronic diseases, such as heart disease, cancer, high blood pressure, and diabetes. This review discusses the body's response to an acute bout of exercise and long‐term physiological adaptations to exercise training with an emphasis on endurance exercise. An overview is provided of skeletal muscle actions, muscle fiber types, and the major metabolic pathways involved in energy production. The importance of adequate fluid intake during exercise sessions to prevent impairments induced by dehydration on endurance exercise, muscular power, and strength is discussed. Physiological adaptations that result from regular exercise training such as increases in cardiorespiratory capacity and strength are mentioned. The review emphasizes the cardiovascular and metabolic adaptations that lead to improvements in maximal oxygen capacity.
Prevalence of otomycosis in Khouzestan Province, south-west Iran
Authors: Saki N , Rafiei A , Nikakhlagh S , Amirrajab N , Saki S
Published: November 2012

Background:

This study aimed to investigate the prevalence of otomycosis and aetiological agents in Khouzestan province, south-west Iran.

Methods:

This cross-sectional study examined and cultured 881 swabs from suspected external otitis cases, collected from throughout Khouzestan province. Fungal agents were identified by slide culture and complementary tests when necessary.

Results:

The mean patient age was 37 years. The 20–39 year age group had the highest prevalence of otomycosis: 293 cases, comprising 162 (55.3 per cent) women and 131 (44.7 per cent) men. The seasonal distribution of cases was: summer, 44.7 per cent; autumn, 28.7 per cent; winter, 14.7 per cent; and spring, 11.9 per cent. The fungal agents isolated wereAspergillus niger(67.2 per cent),Aspergillus flavus(13 per cent),Candida albicans(11.6 per cent),Aspergillus fumigatus(6.2 per cent) and penicillium species (2 per cent).

Conclusion:

Fungal otomycosis is still one of the most important external ear diseases. In this study in south-west Iran,Aspergillus nigerwas the predominant aetiological agent. However, clinicians should be cautious of candidal otomycosis, which has a lower rate of incidence but is more prevalent among 20–39 year olds.
Remission, continuation and incidence of eating disorders during early pregnancy: a validation study in a population-based birth cohort
Authors: Watson H. J. , Von Holle A. , Hamer R. M. , Knoph Berg C. , Torgersen L. , Magnus P. , Stoltenberg C. , Sullivan P. , Reichborn-Kjennerud T. , Bulik C. M.
Published: November 2012

Background

We internally validated previously published rates of remission, continuation and incidence of broadly defined eating disorders during pregnancy in the Norwegian Mother and Child Cohort (MoBa) at the Norwegian Institute of Public Health.

Method

A total of 77 267 pregnant women enrolled at 17 weeks gestation between 2001 and 2009 were split into a training sample (n = 41 243) from the version 2 dataset and a validation sample (n = 36 024) from the version 5 dataset who were not in the original study. Internal validation of original rate models involved fitting a calibration model to compare model parameters between the two samples and bootstrap estimates of bias in the entire version 5 dataset.

Results

Remission, continuation and incidence estimates remained stable. Pre-pregnancy prevalence estimates in the validation sample were: anorexia nervosa (AN; 0.1%), bulimia nervosa (BN; 1.0%), binge eating disorder (BED; 3.3%) and eating disorder not otherwise specified-purging disorder (EDNOS-P; 0.1%). In early pregnancy, estimates were: BN (0.2%), BED (4.8%) and EDNOS-P (<0.01%). Incident BN and EDNOS-P during pregnancy were rare. The highest rates were for full or partial remission for BN and EDNOS-P and continuation for BED.

Conclusions

We validated previously estimated rates of remission, continuation and incidence of eating disorders during pregnancy. Eating disorders, especially BED, during pregnancy were relatively common, occurring in nearly one in every 20 women. Pregnancy was a window of remission from BN but a window of vulnerability for BED. Training to detect eating disorders by obstetricians/gynecologists and interventions to enhance pregnancy and neonatal outcomes warrant attention.
Performing Holocaust Memory: Judd Ne'eman's Zitra
Authors: Burstein Janet Handler
Published: November 2012

Memory and its representations can reveal as much about a culture's sense of itself as they do about its past. Israeli critics have traced the ways in which representations of the Holocaust in their country's films reflect, among many other issues, Israeli culture's preoccupation with the construction of Israeli identity. According to one critic, the Holocaust survivor in films of the 1940s and 1950s embodied weakness and passivity: “all the traits that Israeli identity [was] meant to contrast.” In the 1970s, another critic suggests, films “read” the Holocaust from a “nationalist perspective…highlighting heroic resistance….” Thus, within a few decades, Israeli cinema seems to have represented in radically different ways—through the lens of the Holocaust—the intricacies of Israeli identity formation: first, by shaping memory in terms of the putative weaknesses of diaspora Jews, contrasting them with the strengths of the “new” Israeli Jew; and later, by emphasizing characteristics that linked heroic resisters with heroic Israelis.
Outcome of patent ductus arteriosus ligation in premature infants in the East of England: a prospective cohort study
Authors: Kang Sok-Leng , Samsudin Salehuddin , Kuruvilla Minju , Dhelaria Anshoo , Kent Sue , Kelsall Wilfred A.
Published: November 2012

Background

Surgical ligation of patent ductus arteriosus is considered when medical treatment fails or is contraindicated. This study aims to determine the mortality and morbidity of preterm neonates referred for patent ductus arteriosus ligation.

Methods

A prospective study was conducted in the East of England to follow the outcome of premature infants under 37 weeks’ gestation undergoing patent ductus arteriosus ligation. A standardised proforma was used to collect information before and after the procedure.

Results

A total of 102 premature infants were recruited, and patent ductus arteriosus ligation was performed in 92. Surgical complications occurred in 8.7% (8/92), which included pneumothorax (5/8), recurrent laryngeal nerve palsy (2/8), and chylothorax (1/8). Morbidity outcome data were not available for all infants. The incidence of chronic lung disease was 88% (88/99); intraventricular haemorrhage was 49% (49/100); necrotising enterocolitis 39% (39/99), and retinopathy of prematurity 42% (41/97). The overall mortality rate in our study was 7.8% (8/102). Mortality rate in infants who had patent ductus arteriosus ligation was 4.3% (4/92). The 30-day survival rate after ligation was 99% (91/92). Beyond 30 days post-ligation, three infants died from other causes that were not directly related to surgery.

Conclusion

Patent ductus arteriosus ligation in premature infants is associated with low mortality and complication rates; however, there is a high incidence of neonatal morbidity. Surgical capacity for patent ductus arteriosus ligation needs to be carefully planned nationally as the duration of “waiting time” and transport to another surgical centre could adversely affect outcomes in this high-risk population.
POLICY RULES, REGIME SWITCHES, AND TREND INFLATION: AN EMPIRICAL INVESTIGATION FOR THE UNITED STATES
Authors: Castelnuovo Efrem , Greco Luciano , Raggi Davide
Published: November 2012

This paper estimates Taylor rules featuring instabilities in policy parameters and switches in policy shocks’ volatility for the post-World War II (WWII) U.S. economy. We contrast a rule embedding a fixed-inflation target with another featuring trend inflation, i.e., a time-varying inflation target. The rule embedding trend inflation turns out to be (a) empirically superior according to a marginal likelihood-based comparison and (b) more able to pin down some relevant episodes of the post-WWII U.S. monetary policy history. Estimates conducted with Greenbook data confirm the empirical superiority of the rule featuring a time-varying inflation target. A comparison with recently published estimates of trend inflation is also conducted.
Modeling of word translation: Activation flow from concepts to lexical items
Authors: ROELOFS ARDI , DIJKSTRA TON , GERAKAKI SVETLANA
Published: November 2012

Whereas most theoretical and computational models assume a continuous flow of activation from concepts to lexical items in spoken word production, one prominent model assumes that the mapping of concepts onto words happens in a discrete fashion (Bloem & La Heij, 2003). Semantic facilitation of context pictures on word translation has been taken to support the discrete-flow model. Here, we report results of computer simulations with the continuous-flow WEAVER++ model (Roelofs, 1992, 2006) demonstrating that the empirical observation taken to be in favor of discrete models is, in fact, only consistent with those models and equally compatible with more continuous models of word production by monolingual and bilingual speakers. Continuous models are specifically and independently supported by other empirical evidence on the effect of context pictures on native word production.
25-Hydroxyvitamin D insufficiency is associated with cardiometabolic risk in Korean adolescents: the 2008–2009 Korea National Health and Nutrition Examination Survey (KNHANES)
Authors: Nam Ga Eun , Kim Do Hoon , Cho Kyung Hwan , Park Yong Gyu , Han Kyung Do , Kim Seon Mee , Lee Seung Hwan , Ko Byung Joon , Ji Kim Min
Published: November 2012

Objective

Vitamin D insufficiency is known to be related to cardiometabolic disorders; however, the associations among serum 25-hydroxyvitamin D (25(OH)D) concentration and metabolic syndrome and cardiometabolic risk factors in children and adolescents have not yet been clearly delineated. For this reason, we investigated the relationship among serum 25(OH)D concentration and metabolic syndrome and cardiometabolic risk factors among Korean adolescents.

Design

We performed a cross-sectional analysis and used hierarchical multivariate logistic regression analysis models to adjust for confounding variables.

Setting

We used the data gathered during the 2008–2009 Korea National Health and Nutrition Examination Survey (KNHANES).

Subjects

Our subjects included 1504 Korean adolescents aged 12–18 years who participated in the KNHANES.

Results

Vitamin D insufficiency, defined as 25(OH)D concentration <50 nmol/l, was found in 75·3 % of Korean adolescents and was associated with an increased risk of the prevalence of metabolic syndrome. Waist circumference and BMI were the most closely correlated cardiometabolic components of metabolic syndrome according to serum 25(OH)D status, but no significant relationship was found between serum 25(OH)D concentration and insulin resistance or for the risks for high blood pressure, hyperglycaemia, reduced HDL-cholesterol or hypertriacylglycerolaemia, with or without adjustment for confounding variables.

Conclusions

Low serum 25(OH)D concentration appears to be associated with several cardiometabolic risk factors and an increased risk of the prevalence of metabolic syndrome in Korean adolescents.
Hyperspectral Cathodoluminescence Imaging and Analysis Extending from Ultraviolet to Near Infrared
Authors: MacRae C.M. , Wilson N.C. , Torpy A. , Davidson C.J.
Published: November 2012

The measurement of near-infrared (NIR) cathodoluminescence (CL) with sufficient sensitivity to allow full spectral mapping has been investigated through the application of optimized grating spectrometers that allow the ultraviolet (UV), visible, and NIR CL spectra to be measured simultaneously. Two optical spectrometers have been integrated into an electron microprobe, allowing simultaneous collection of hyperspectral CL (UV-NIR), characteristic X-rays, and electron signals. Combined hyperspectral CL spectra collected from two natural apatite (Ca5[PO4]3[OH,F]) samples from Wilberforce (Ontario, Canada) and Durango (Mexico) were qualitatively analyzed to identify the emission centers and then deconvoluted pixel-by-pixel using least-squares fitting to produce a series of ion-resolved CL intensity maps. Preliminary investigation of apatite has shown strong NIR emissions associated primarily with the rare-earth element Nd. Details of growth and alteration were revealed in the NIR that were not discernable with electron-induced X-ray mapping. Intense emission centers from Nd3+ and Sm3+ were observed in the spectra from both apatites, along with minor emissions from other 3+ rare-earth elements. Quantitative electron probe microanalysis was performed on points within the mapped area of the Durango apatite to produce a calibration line relating cathodoluminescent intensity of the fitted peak centered at 1,073 nm (1.156 eV) to the Nd concentration.
Region-specific effects on BDNF expression after contingent or non-contingent cocaine i.v. self-administration in rats
Authors: Fumagalli Fabio , Moro Federico , Caffino Lucia , Orrù Alessandro , Cassina Chiara , Giannotti Giuseppe , Di Clemente Angelo , Racagni Giorgio , Riva Marco A. , Cervo Luigi
Published: November 2012

Brain-derived neurotrophic factor (BDNF) dynamic changes were investigated in the medial prefrontal cortex (mPFC) and nucleus accumbens (NAc) during use and the early phases of cocaine abstinence after 14 sessions (2 h self-administration/d; 0.25 mg/0.1 ml.6 s infusion) by employing a ‘yoked control-operant paradigm'. The effect on BDNF was region-specific and dependent on the withdrawal time. In the NAc, BDNF protein levels increased immediately after the last self-administration session, with a larger increase in passively cocaine-exposed rats. In the mPFC, BDNF expression was elevated 24 h after the last self-administration session, independently of how the drug was encountered. No changes were found in NAc and mPFC 7 d after the last self-administration session. Analysis of transcript levels in the mPFC indicated that action on exon I might contribute to BDNF's cortical induction. These findings indicate a finely tuned modulation of BDNF expression during use and early phases of cocaine abstinence.
Electromagnetic waves and electron anisotropies downstream of supercritical interplanetary shocks
Authors: Wilson L. B. , Koval A. , Szabo A. , Breneman A. , Cattell C. A. , Goetz K. , Kellogg P. J. , Kersten K. , Kasper J. C. , Maruca B. A. , Pulupa M.
Published: November 2012

We present waveform observations of electromagnetic lower hybrid and whistler waves with fci ≪ f < fce downstream of four supercritical interplanetary shocks using the Wind search coil magnetometer. The whistler waves were observed to have a weak positive correlation between δB and normalized heat flux magnitude and an inverse correlation with Teh/Tec. All were observed simultaneous with electron distributions satisfying the whistler heat flux instability threshold and most with T⊥ h/T∥ h > 1.01. Thus, the whistler mode waves appear to be driven by a heat flux instability and cause perpendicular heating of the halo electrons. The lower hybrid waves show a much weaker correlation between δB and normalized heat flux magnitude and are often observed near magnetic field gradients. A third type of event shows fluctuations consistent with a mixture of both lower hybrid and whistler mode waves. These results suggest that whistler waves may indeed be regulating the electron heat flux and the halo temperature anisotropy, which is important for theories and simulations of electron distribution evolution from the Sun to the Earth.
Predicting the lithospheric stress field and plate motions by joint modeling of lithosphere and mantle dynamics
Authors: Ghosh A. , Holt W. E. , Wen L.
Published: November 2012

The way in which basal tractions, associated with mantle convection, couples with the lithosphere is a fundamental problem in geodynamics. A successful lithosphere‐mantle coupling model for the Earth will satisfy observations of plate motions, intraplate stresses, and the plate boundary zone deformation. We solve the depth integrated three‐dimensional force balance equations in a global finite element model that takes into account effects of both topography and shallow lithosphere structure as well as tractions originating from deeper mantle convection. The contribution from topography and lithosphere structure is estimated by calculating gravitational potential energy differences. The basal tractions are derived from a fully dynamic flow model with both radial and lateral viscosity variations. We simultaneously fit stresses and plate motions in order to delineate a best‐fit lithosphere‐mantle coupling model. We use both the World Stress Map and the Global Strain Rate Model to constrain the models. We find that a strongly coupled model with a stiff lithosphere and 3–4 orders of lateral viscosity variations in the lithosphere are best able to match the observational constraints. Our predicted deviatoric stresses, which are dominated by contribution from mantle tractions, range between 20–70 MPa. The best‐fitting coupled models predict strain rates that are consistent with observations. That is, the intraplate areas are nearly rigid whereas plate boundaries and some other continental deformation zones display high strain rates. Comparison of mantle tractions and surface velocities indicate that in most areas tractions are driving, although in a few regions, including western North America, tractions are resistive.
Diagnosis of water mass transformation and formation rates in a high‐resolution GCM of the North Pacific
Authors: Nishikawa S. , Tsujino H. , Sakamoto K. , Nakano H.
Published: November 2012

We studied the relationship between assessments of water mass formation estimated by thermodynamic and kinematic methods by applying both methods to the Subtropical Mode Water (STMW) and Central Mode Water (CMW) formation regions of the North Pacific. We used long‐term outputs of a high‐resolution general circulation model under climatological normal year forcings to calculate the water mass transformation rate and its density derivative (the net formation rate) and to examine the roles of mixing, shortwave penetration, and mesoscale eddies. Diagnosis of the thermodynamic relationship indicated that the transformation rate associated with surface density flux largely explained the net transformation rate. The difference of these rates, the total mixing effect, was relatively small compared with previous estimates. Explicit and implicit mixing largely explained the total mixing effect. Diagnosis of the kinematic relationship indicated that the annual subduction rate could be calculated from the net transformation rate and the open boundary volume flux over the analysis region. Comparison of both methods implied that the source of subducted STMW was determined mainly by the transformation associated with surface density flux, but this conclusion was not true for CMW. The modeled effects of internal mixing and volume flux from the north (Oyashio Current) also became important in the formation of CMW. Omission of shortwave penetration led to an error in the air‐sea transformation and formation rates in the STMW and CMW regions. We also found the important roles of mesoscale eddies in the transformation and formation of mode waters.
Identification and control of subglacial water networks under Dome A, Antarctica
Authors: Wolovick Michael J. , Bell Robin E. , Creyts Timothy T. , Frearson Nicholas
Published: November 2012

Subglacial water in continental Antarctica forms by melting of basal ice due to geothermal or frictional heating. Subglacial networks transport the water from melting areas and can facilitate sliding by the ice sheet over its bed. Subglacial water flow is driven mainly by gradients in overburden pressure and bed elevation. We identify small (median 850 m) water bodies within the Gamburtsev Subglacial Mountains in East Antarctica organized into long (20–103 km) coherent drainage networks using a dense (5 km) grid of airborne radar data. The individual water bodies are smaller on average than the water bodies contained in existing inventories of Antarctic subglacial water and most are smaller than the mean ice thickness of 2.5 km, reflecting a focusing of basal water by rugged topography. The water system in the Gamburtsev Subglacial Mountains reoccupies a system of alpine overdeepenings created by valley glaciers in the early growth phase of the East Antarctic Ice Sheet. The networks follow valley floors either uphill or downhill depending on the gradient of the ice sheet surface. In cases where the networks follow valley floors uphill they terminate in or near plumes of freeze‐on ice, indicating source to sink transport within the basal hydrologic system. Because the ice surface determines drainage direction within the bed‐constrained network, the system is bed‐routed but surface‐directed. Along‐flow variability in the structure of the freeze‐on plumes suggests variability in the networks on long (10s of ka) timescales, possibly indicating changes in the basal thermal state.
General performance characteristics and parametric optimum bounds of irreversible chemical engines
Authors: Guo Juncheng , Wang Yuan , Chen Jincan
Published: November 2012

Based on the weak-dissipation assumption, a general cycle model of irreversible chemical engines, including non-isothermal chemical engines, isothermal chemical engines, and other classes of heat engines is established, where finite-rate heat and mass transfers are considered. Expressions for the power output and efficiency of the cycle system are derived. The power output is optimized for a given efficiency of the cycle system by using the Lagrangian-multiplier method and the corresponding characteristic curves are represented. The region of the efficiency of the cycle system at the maximum power output is determined. The results obtained may be directly used to discuss the optimal performance of non-isothermal chemical engines, isothermal chemical engines, and heat engines. Furthermore, it is explained that when different values of two dissipation parameters in the model are chosen, these results obtained may be further used to derive the optimal performance of several novel thermodynamic cycles, such as quantum heat engines, Brownian heat engines, etc. It is thus clear that the results obtained here are not only universal but also important.
Quantifying the transverse deformability of double-walled carbon and boron nitride nanotubes using an ultrathin nanomembrane covering scheme
Authors: Zheng Meng , Zou Lian-feng , Wang Howard , Park Cheol , Ke Changhong
Published: November 2012

We investigate the characterization of the transverse deformability of double-walled carbon and boron-nitride nanotubes (i.e., DWCNTs and DWBNNTs) using an ultrathin nanomembrane covering scheme. Monolayer graphene oxide sheets (MGOSs) with a sub-nm thickness are used to cover individual double-walled nanotubes on flat substrates. Nanotube cross-section height reduction occurs due to the compression force exerted by the covering membrane, whose morphological conformation is governed by its bending/stretching rigidities and adhesion interaction with the substrate, as well as the radial height and rigidity of the underlying nanotube. The actual transverse deformation of the underlying tube and its effective radial modulus are quantified through interpreting the measured structural morphology of the covering membrane and the nanotube cross-section height reduction using nonlinear structural mechanics and Hertzian contact mechanics theories. The radial deformations in MGOS-covered tubes are found to positively correlate with the nanotube radial rigidity, thus, increasing with the nanotube outer diameter and decreasing with an increase of the number of tube walls. Our results reveal prominent radial strains of about 20% for DWCNTs of 3.55 nm in outer diameter, while about 24% for DWBNNTs of 3.85 nm in outer diameter. Our data about the effective radial moduli of individual DWCNTs and DWBNNTs are in reasonably good agreement with those obtained using atomic force microscopy-based compression methods. Our work shows that the nanomembrane covering scheme is promising as a quantitative technique for studying the radial rigidity of individual tubular nanostructures.
Expression patterns of activin, inhibin and follistatin variants in the adult male mouse reproductive tract suggest important roles in the epididymis and vas deferens
Authors: Winnall Wendy R. , Wu Hui , Sarraj Mai A. , Rogers Peter A. W. , de Kretser David M. , Girling Jane E. , Hedger Mark P.
Published: November 2012

Activin A and its inhibitors follistatin and inhibin play key roles in development and function of the male reproductive tract. Quantitative (q) polymerase chain reaction (PCR) was used to evaluate the expression of Inhba (the gene encoding activin A subunits), Inha and Inhbb (genes encoding the inhibin B subunits), as well as the genes for follistatin (Fst) and follistatin-like 3 (Fstl3) and the activin receptor subunits, in the male mouse reproductive tract. A qPCR assay that discriminated between the two follistatin variants of Fst288 (tissue-bound form) and Fst315 (circulating) was established. Activin A protein was measured by ELISA, whereas the inhibin α-subunit and total follistatin proteins were measured by radioimmunoassay (RIA). A screen of 22 tissues demonstrated tissue-specific regulation of the follistatin variants, with Fst288 highly expressed in the vas deferens and Fst315 most highly expressed in the skin. The expression of Fst288 and Fst315 and follistatin protein levels increased progressively from the testis through to the distal vas deferens. Inhba and the activin receptors were highly expressed in the epididymis, but activin A protein was elevated in both the epididymis and vas deferens. Inhibin α-subunit mRNA and protein and Inhbb expression were highest in the testis. These results indicate a role for activin A within the epididymis, but also that activin A bioactivity may be increasingly inhibited by follistatin distally along the male reproductive tract.
Relation between anaerobic inactivation and oxygen tolerance in a large series of NiFe hydrogenase mutants
Authors: Abou Hamdan Abbas , Liebgott Pierre-Pol , Fourmond Vincent , Gutiérrez-Sanz Oscar , De Lacey Antonio L. , Infossi Pascale , Rousset Marc , Dementin Sébastien , Léger Christophe
Published: November 2012

Nickel-containing hydrogenases, the biological catalysts of

oxidation and production, reversibly inactivate under anaerobic, oxidizing conditions. We aim at understanding the mechanism of (in)activation and what determines its kinetics, because there is a correlation between fast reductive reactivation and oxygen tolerance, a property of some hydrogenases that is very desirable from the point of view of biotechnology. Direct electrochemistry is potentially very useful for learning about the redox-dependent conversions between active and inactive forms of hydrogenase, but the voltammetric signals are complex and often misread. Here we describe simple analytical models that we used to characterize and compare 16 mutants, obtained by substituting the position-74 valine of the

-sensitive NiFe hydrogenase from
Desulfovibrio fructosovorans
. We observed that this substitution can accelerate reactivation up to 1,000-fold, depending on the polarity of the position 74 amino acid side chain. In terms of kinetics of anaerobic (in)activation and oxygen tolerance, the valine-to-histidine mutation has the most spectacular effect: The V74H mutant compares favorably with the

-tolerant hydrogenase from
Aquifex aeolicus
, which we use here as a benchmark.
Conditionally reprogrammed cells represent a stem-like state of adult epithelial cells
Authors: Suprynowicz Frank A. , Upadhyay Geeta , Krawczyk Ewa , Kramer Sarah C. , Hebert Jess D. , Liu Xuefeng , Yuan Hang , Cheluvaraju Chaitra , Clapp Phillip W. , Boucher Richard C. , Kamonjoh Christopher M. , Randell Scott H. , Schlegel Richard
Published: November 2012

The combination of irradiated fibroblast feeder cells and Rho kinase inhibitor, Y-27632, conditionally induces an indefinite proliferative state in primary mammalian epithelial cells. These conditionally reprogrammed cells (CRCs) are karyotype-stable and nontumorigenic. Because self-renewal is a recognized property of stem cells, we investigated whether Y-27632 and feeder cells induced a stem-like phenotype. We found that CRCs share characteristics of adult stem cells and exhibit up-regulated expression of α6 and β1 integrins, ΔNp63α, CD44, and telomerase reverse transcriptase, as well as decreased Notch signaling and an increased level of nuclear β-catenin. The induction of CRCs is rapid (occurs within 2 d) and results from reprogramming of the entire cell population rather than the selection of a minor subpopulation. CRCs do not overexpress the transcription factor sets characteristic of embryonic or induced pluripotent stem cells (e.g., Sox2, Oct4, Nanog, or Klf4). The induction of CRCs is also reversible, and removal of Y-27632 and feeders allows the cells to differentiate normally. Thus, when CRCs from ectocervical epithelium or tracheal epithelium are placed in an air–liquid interface culture system, the cervical cells form a well differentiated stratified squamous epithelium, whereas the tracheal cells form a ciliated airway epithelium. We discuss the diagnostic and therapeutic opportunities afforded by a method that can generate adult stem-like cells in vitro without genetic manipulation.