bluuebunny/crossref_metadata_2025 huggingface dataset:
Layer‐by‐Layer Controlled Perovskite Nanocomposite Thin Films for Piezoelectric Nanogenerators
Authors: Kim Younghoon , Lee Keun Young , Hwang Sun Kak , Park Cheolmin , Kim Sang‐Woo , Cho Jinhan
Published: August 2014

Perovskite nanoparticle‐based nanocomposite thin films strictly tailored using unconventional layer‐by‐layer (LbL) assembly in organic media for piezoelectric nanogenerators (NGs) are demonstrated. By employing sub‐20‐nm BaTiO3 nanoparticles stabilized by oleic acid ligands (i.e., OA‐BTONPs) and carboxylic acid (COOH)‐functionalized polymers, such as poly(acrylic acid) (PAA), the resulting OA‐BTONP/PAA nanocomposite multilayers are prepared by exploiting the high affinity between the COOH groups of PAA and the BTONPs. The ferroelectric and piezoelectric performance of the (PAA/OA‐BTONP)n thin films can be precisely controlled by altering the bilayer number, inserted polymer type, and OA‐BTONP size. It is found that the LbL assembly in nonpolar solvent media can effectively increase the quantity of adsorbed OA‐BTONPs, resulting in the dramatic enhancement of electric power output from the piezoelectric NGs. Furthermore, very low leakage currents are detected from the (PAA/OA‐BTONP)n thin films for obtaining highly reliable power‐generating performance of piezoelectric NGs.
The anthropometry of children and adolescents may be influenced by the prenatal smoking habits of their grandmothers: A longitudinal cohort study
Authors: Golding Jean , Northstone Kate , Gregory Steven , Miller Laura L. , Pembrey Marcus
Published: August 2014

Objectives

Previously, in the Avon Longitudinal Study of Parents and Children (ALSPAC), we have shown different sex‐specific birth anthropometric measurements contingent upon whether or not prenatal smoking was undertaken by paternal grandmother (PGM±), maternal grandmother (MGM±), and the study mother (M±). The findings raised the question as to whether there were long‐term associations on the growth of the study children over time.

Methods

Measures of weight, height, body mass index, waist circumference, lean mass, and fat mass of children in the ALSPAC study from 7 to 17 years of age were used. We compared growth in four categories at each age: PGM+M− with PGM−M−; MGM+M− with MGM−M−; PGM+M+ with PGM−M+; MGM+M+ with MGM−M+; and adjusted for housing tenure, maternal education, parity, and paternal smoking at the start of the study pregnancy.

Results

We found that if the PGM had, but the study mother had not, smoked in pregnancy, the girls were taller and both genders had greater bone and lean mass. However, if the MGM had smoked prenatally but the mother had not (MGM+M−), the boys became heavier than expected with increasing age—an association that was particularly due to lean rather than fat mass, reflected in increased strength and fitness. When both the maternal grandmother and the mother had smoked (MGM+M+) girls had reduced height, weight, and fat/lean/bone mass when compared with girls born to smoking mothers whose own mothers had not smoked (MGM−M+).

Conclusions

This study indicates that smoking in humans can have sex‐specific transgenerational effects. Am. J. Hum. Biol. 26:731–739, 2014. © 2014 The Authors American Journal of Human Biology Published by Wiley Periodicals, Inc.
Sleep duration, sleep quality, and obesity risk among older adults from six middle‐income countries: Findings from the study on global ageing and adult health (SAGE)
Authors: Gildner Theresa E. , Liebert Melissa A. , Kowal Paul , Chatterji Somnath , Josh Snodgrass J.
Published: August 2014

Objectives

Changes in sleep patterns often occur in older adults. Previous studies have documented associations between sleep duration, sleep quality, and obesity risk in older individuals, yet few studies have examined these trends in lower‐income countries. The present cross‐sectional study uses nationally representative datasets from six countries to examine these relationships.

Methods

Two hypotheses related to obesity risk and sleep patterns were tested using data from the first wave of the World Health Organization's Study on global AGEing and adult health (SAGE). This longitudinal study draws on samples of older adults (>50 years old) in six middle‐income countries (China, Ghana, India, Mexico, Russian Federation, and South Africa). Self‐report data were used to measure sleep duration, sleep quality, lifestyle and sociodemographic information, while anthropometric measurements were collected to assess body mass index (BMI) and waist circumference (WC). Multiple linear regressions were used to examine the relationship between sleep patterns and obesity risk while controlling for lifestyle factors.

Results

Shorter sleep durations in both men and women were significantly associated with higher BMI and WC measures (P < 0.05). Low sleep quality did not significantly contribute to increased obesity risk. Surprisingly, high sleep quality was significantly associated with increased male BMI and WC in China and India (P < 0.01).

Conclusions

This study documented an association between short sleep duration and increased obesity risk, which is important given the global increase of obesity‐related diseases. Am. J. Hum. Biol. 26:803–812, 2014. © 2014 Wiley Periodicals, Inc.
Electrospinning of chitosan/poly(lactic acid) nanofibers: The favorable effect of nonionic surfactant
Authors: Shan Xiaoqian , Li Fengqian , Liu Changsheng , Gao Qun
Published: August 2014

To improve the electrospinnability of chitosan (CS), a series of nanofiber membrane blends comprised of CS, poly(lactic acid) (PLA), and nonionic surfactant polyoxyethylene nonylphenol ether (TX‐15), were made. Uniform nanofibers with no bead‐like structures were obtained from solutions of 2% TX‐15 with 6% CS(50)/PLA(50). The diameter was between 200 and 300 nm. We found that with increasing TX‐15 in the blend, the nanofibers displayed more hydrophilicity. Compared to CS/PLA nanofibers, the blend polymers with TX‐15 had better tensile mechanical properties. Finally, all cells examined showed high levels of attachment and spreading on CS/PLA/TX‐15 nanofibers with a TX‐15 content of 0∼3%. Thus, the nanofibers were nontoxic. In conclusion, adding PLA and TX‐15 to CS via solution‐blending and electrospinning may be an effective way to toughen CS nanofibers and make them more suitable for drug delivery or tissue engineering applications. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 41098.
Synthesis and thermomechanical properties of allyl‐functionalized polycaprolactone urethane‐co‐2‐hydroxylethyl methacrylate networks
Authors: Shen Hang , Quintard Guilhem , Chen Jianding , Taha Mohamed
Published: August 2014

PCL‐segmented multiallyl‐functionalized poly (ester urethane) prepolymers (PEUs) were prepared in a two‐step process. First, hydroxyl‐terminated PCL and glycerol simultaneously reacted with an excess of a diisocyanate, the obtained isocyanate functionalized prepolymers then reacts with allyl amine. PEUs structure choice mainly focused on two aspects: the PCL segments concentration and the allyl functionality that, respectively, affects the biodegradability and the density of the issued networks. The concentrations of the different reactants were fixed, taking into account the desired mean structure and also to prevent crosslinking during the synthesis of the prepolymers. FTIR was principally used to monitor the synthesis of allyl functionalized PEUs. The carbonyl absorption of PCL, initially located at 1720 cm−1, reaction of the PCL and shifted toward 1730 cm−1, due to a decrease in crystallinity as confirmed by DSC. The structure of allyl‐functionalized PCL‐segmented PEU analyzed by 1H NMR, double bond content was between 0.2 and 1.2 mmol g−1. Networks were obtained by UV‐initiated radical copolymerization of allyl‐functionalized PEUs and HEMA. The effects of PCL concentration and molar mass on their thermomechanical and thermal properties were analyzed. Particular damping properties were obtained. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41295.
Effect of passive polarizing three-dimensional displays on surgical performance for experienced laparoscopic surgeons
Authors: Smith R , Schwab K , Day A , Rockall T , Ballard K , Bailey M , Jourdan I
Published: August 2014

Background

Although the potential benefits of stereoscopic laparoscopy have been recognized for years, the technology has not been adopted because of poor operator tolerance. Passive polarizing projection systems, which have revolutionized three-dimensional (3D) cinema, are now being trialled in surgery. This study was designed to see whether this technology resulted in significant performance benefits for skilled laparoscopists.

Methods

Four validated laparoscopic skills tasks, each with ten repetitions, were performed by 20 experienced laparoscopic surgeons, in both two-dimensional (2D) and 3D conditions. The primary outcome measure was the performance error rate; secondary outcome measures were time for task completion, 3D motion tracking (path length, motion smoothness and grasping frequency) and workload dimension ratings of the National Aeronautics and Space Administration (NASA) Task Load Index.

Results

Surgeons demonstrated a 62 per cent reduction in the median number of errors and a 35 per cent reduction in median performance time when using the passive polarizing 3D display compared with the 2D display. There was a significant 15 per cent reduction in median instrument path length, an enhancement of median motion smoothness, and a 15 per cent decrease in grasper frequency with the 3D display. Participants reported significant reductions in subjective workload dimension ratings of the NASA Task Load Index following use of the 3D displays.

Conclusion

Passive polarizing 3D displays improved both the performance of experienced surgeons in a simulated setting and surgeon perception of the operative field. Although it has been argued that the experience of skilled laparoscopic surgeons compensates fully for the loss of stereopsis, this study indicates that this is not the case.
Single‐Molecule‐Magnet Behavior in the Family of [Ln(OETAP)2] Double‐Decker Complexes (Ln=Lanthanide, OETAP=Octa(ethyl)tetraazaporphyrin)
Authors: Giménez‐Agulló Nelson , de Pipaón Cristina Sáenz , Adriaenssens Louis , Filibian Marta , Martínez‐Belmonte Marta , Escudero‐Adán Eduardo C. , Carretta Pietro , Ballester Pablo , Galán‐Mascarós José Ramón
Published: August 2014

Double‐decker complexes of lanthanide cations can be readily prepared with tetraazaporphyrins (porphyrazines). We have synthesized and characterized a series of neutral double‐decker complexes [Ln(OETAP)2] (Ln=Tb3+, Dy3+, Gd3+, Y3+; OETAP=octa(ethyl)tetraazaporphyrin). Some of these complexes show analogous magnetic features to their phthalocyanine (Pc) counterparts. The Tb3+ and Dy3+ derivatives exhibit single‐molecule magnet (SMM) behavior with high blocking temperatures over 50 and 10 K, respectively. These results confirm that, in double‐decker complexes that involve Tb or Dy, the (N4)2 square antiprism coordination mode has an important role in inducing very large activation energies for magnetization reversal. In contrast with their Pc counterparts, the use of tetraazaporphyrin ligands endows the presented [Ln(OETAP)2] complexes with extraordinary chemical versatility. The double‐decker complexes that exhibit SMM behavior are highly soluble in common organic solvents, and easily processable even through sublimation.
Numerical prediction of acoustic streaming in a microcuvette
Authors: Catarino Susana O. , Miranda Joao M. , Lanceros‐Mendez Senentxu , Minas Graca
Published: August 2014

This paper reports the modelling and simulation of the acoustic streaming phenomenon, generated by a polymeric piezoelectric transducer, used for promoting fluid mixing in microfluidic devices. The acoustic streaming process consists of the absorption of the acoustic waves by the fluid which results in a pressure drop along the direction of the acoustic propagation. The generated pressure drop promotes the flow and consequently mixing. This process overcomes the slow molecular diffusion resultant from the low Reynolds number that leads to laminar flows in microcuvettes. The numerical model comprises the compressible Navier‐Stokes equations, whose variables were expanded in first‐ and second‐order values, to overcome the great difference between the piezoelectric and the fluid flow time scales. The model was implemented in OpenFoam software, through finite volumes numerical methods. It was concluded that the excitation of the transducer above the microcuvette generates a mean global flow with visible recirculation of fluids within the domain, which can be used to predict the fluid flow behaviour.
A novel HoxB cluster protein expressed in the hindbrain and pharyngeal arches
Authors: Saxena Ankur , Bronner Marianne E.
Published: August 2014

We describe a novel zebrafish line that fluorescently tags a previously unknown protein, CT74a, allowing us to follow its endogenous expression in real time and at subcellular resolution in live embryos. Our results showed that CT74a‐Citrine fusion protein is expressed in the developing pharyngeal arches, hindbrain, and fin buds in a pattern highly reminiscent of transcription factors belonging to anterior Hox gene families, including expression in a subset of neuronal nuclei. Consistent with this, splinkerette‐PCR revealed that CT74a‐Citrine's genomic integration is within the HoxB region, and 3′ RACE demonstrated that its downstream coding sequence has no recognizable homology. Thus, CT74a is a previously unknown protein located within the HoxB cluster adjacent to Hoxb4a and is expressed in a Hoxb4a‐like pattern. genesis 52:858–863, 2014. © 2014 Wiley Periodicals, Inc.
High prevalence of vitamin D deficiency and insufficiency in adolescent inpatients diagnosed with eating disorders
Authors: Modan‐Moses Dalit , Levy‐Shraga Yael , Pinhas‐Hamiel Orit , Kochavi Brigitte , Enoch‐Levy Adi , Vered Iris , Stein Daniel
Published: August 2014

Objective

Previous studies assessing vitamin D status in adolescents with eating disorders showed inconsistent results. The aim of the current study was to assess vitamin D status in a large cohort of adolescent inpatients with eating disorders and its relation to bone mineral density (BMD) and depression.

Method

25‐Hydroxyvitamin D (25OHD), calcium, phosphorus, and alkaline phosphatase levels as well as BMD and depression were assessed on admission in 87 inpatients (aged 16 ± 2 years, females = 81) with eating disorders [anorexia nervosa (AN) = 64; bulimia nervosa (BN) = 5; eating disorders not otherwise specified‐binge/purge type (EDNOS‐B/P) = 18].

Results

Mean 25OHD levels were 24.1 ± 7.5 ng/ml (25.0 ± 7.6, 25.4 ± 9.9, and 22.0 ± 9.9 ng/ml in patients with AB, BN, and EDNOS‐B/P, respectively). Vitamin D deficiency (<15 ng/ml) was found in 7.8% of the patients, and insufficiency (15–20 ng/ml) in 22.2%. Only 16.7% had levels >32 ng/ml, considered optimal by some experts. No associations were found between 25OHD levels and BMD or comorbid depression. 25OHD levels during winter were significantly lower than summer levels (p < .001). Mean lumbar spine BMD z‐score in patients with AN and EDNOS‐B/P type was low (−1.5 ± 1.1) and correlated with body mass index standard deviation score (p = .03).

Discussion

Adolescents with eating disorders show a high prevalence of vitamin D deficiency and insufficiency. Given the risk of osteoporosis in this population, 25OHD levels found in this group may not offer optimal bone protection. Vitamin D levels should be routinely checked and supplementation should be administered as required. © 2014 Wiley Periodicals, Inc. (Int J Eat Disord 2015; 48: 607–614)
Insights from ecological niche modeling on the taxonomic distinction and niche differentiation between the black‐spotted and red‐spotted tokay geckoes (Gekko gecko)
Authors: Zhang Yueyun , Chen Chongtao , Li Li , Zhao Chengjian , Chen Weicai , Huang Yong
Published: August 2014

The black‐spotted tokay and the red‐spotted tokay are morphologically distinct and have largely allopatric distributions. The black‐spotted tokay is characterized by a small body size and dark skin with sundry spots, while the red‐spotted tokay has a relatively large body size and red spots. Based on morphological, karyotypic, genetic, and distribution differences, recent studies suggested their species status; however, their classifications remain controversial, and additional data such as ecological niches are necessary to establish firm hypotheses regarding their taxonomic status. We reconstructed their ecological niches models using climatic and geographic data. We then performed niche similarity tests (niche identity and background tests) and point‐based analyses to explore whether ecological differentiation has occurred, and whether such differences are sufficient to explain the maintenance of their separate segments of environmental ranges. We found that both niche models of the black‐ and the red‐spotted tokay had a good fit and a robust performance, as indicated by the high area under the curve (AUC) values (“black” = 0.982,SD = ± 0.002, “red” = 0.966 ± 0.02). Significant ecological differentiation across the entire geographic range was found, indicating that the involvement of ecological differentiation is important for species differentiation. Divergence along the environmental axes is highly associated with climatic conditions, with isothermality being important for the “black” form, while temperature seasonality, precipitation of warmest quarter, and annual temperature range together being important for the “red” form. These factors are likely important factors in niche differentiation between the two forms, which result in morphological replacement. Overall, beside morphological and genetic differentiation information, our results contribute to additional insights into taxonomic distinction and niche differentiation between the black‐ and the red‐spotted tokay.
Parasitism in early life: environmental conditions shape within‐brood variation in responses to infection
Authors: Granroth‐Wilding Hanna M. V. , Burthe Sarah J. , Lewis Sue , Reed Thomas E. , Herborn Katherine A. , Newell Mark A. , Takahashi Emi A. , Daunt Francis , Cunningham Emma J. A.
Published: August 2014

Parasites play key ecological and evolutionary roles through the costs they impose on their host. In wild populations, the effect of parasitism is likely to vary considerably with environmental conditions, which may affect the availability of resources to hosts for defense. However, the interaction between parasitism and prevailing conditions is rarely quantified. In addition to environmental variation acting on hosts, individuals are likely to vary in their response to parasitism, and the combined effect of both may increase heterogeneity in host responses. Offspring hierarchies, established by parents in response to uncertain rearing conditions, may be an important source of variation between individuals. Here, we use experimental antiparasite treatment across 5 years of variable conditions to test how annual population productivity (a proxy for environmental conditions) and parasitism interact to affect growth and survival of different brood members in juvenile European shags (Phalacrocorax aristotelis). In control broods, last‐hatched chicks had more plastic growth rates, growing faster in more productive years. Older siblings grew at a similar rate in all years. Treatment removed the effect of environment on last‐hatched chicks, such that all siblings in treated broods grew at a similar rate across environmental conditions. There were no differences in nematode burden between years or siblings, suggesting that variation in responses arose from intrinsic differences between chicks. Whole‐brood growth rate was not affected by treatment, indicating that within‐brood differences were driven by a change in resource allocation between siblings rather than a change in overall parental provisioning. We show that gastrointestinal parasites can be a key component of offspring's developmental environment. Our results also demonstrate the value of considering prevailing conditions for our understanding of parasite effects on host life‐history traits. Establishing how environmental conditions shape responses to parasitism is important as environmental variability is predicted to increase.
Energy‐efficient resource allocation for amplify‐and‐forward relaying in OFDM systems
Authors: Kazemi Jafar , Omidi Mohammad Javad , Navaie Keivan
Published: August 2014

In this paper, we study end‐to‐end energy efficiency of an orthogonal frequency‐division multiplexing relay‐based system under power constraints for the base station and relay node with system circuit power considerations. Using a two‐phase amplify‐and‐forward relaying protocol, we assume that relay has a fixed power constraint and the source power can vary in transmission power interval where the source employs a selective relaying mechanism for each individual subcarrier. Therefore, in our model, the source is able to adaptively select some subcarriers to be relayed. The radio resource allocation is then formulated as an energy‐efficient mixed binary integer programming, and then we propose a heuristic algorithm to find the suboptimal solution. The solution consists of the suboptimal transmit power of the source, the suboptimal set of subcarriers for relaying and the optimal transmit power of each subcarrier at the source and relay in the first and second time slots. The algorithm obtains energy‐efficient transmission power for a given relay transmission power based on a gradient descent method. Then a two‐step iterative scheme is proposed to obtain the subcarriers to be relayed as well as the optimal power allocation at the source and relay in the first and second time slots. To evaluate the efficiency of the proposed method, we compare its efficiency through simulations with the cases without using selective subcarrier relaying and without circuit power consideration in low and high relay transmit power regimes. The simulation results indicate that using our proposed method results in a significant improvement in the energy efficiency. Copyright © 2014 John Wiley & Sons, Ltd.
Comparison of diagnostic accuracy of aspartate aminotransferase to platelet ratio index and fibrosis‐4 index for detecting liver fibrosis in adult patients with chronic hepatitis B virus infection: A systemic review and meta‐analysis
Authors: Xiao Guangqin , Yang Jiayin , Yan Lunan
Published: August 2014

The aspartate aminotransferase‐to‐platelet ratio index (APRI) and fibrosis index based on the four factors (Fibrosis 4 index; FIB‐4) are the two most widely studied noninvasive tools for assessing liver fibrosis. Our aims were to systematically review the performance of APRI and FIB‐4 in hepatitis B virus (HBV) infection in adult patients and compare their advantages and disadvantages. We examined the diagnostic accuracy of APRI and FIB‐4 for significant fibrosis, advanced fibrosis, and cirrhosis based on their sensitivity, specificity, positive predictive value, negative predictive value, and area under the receiver operating characteristic curve (AUROC). Heterogeneity was explored using metaregression. Our systemic review and meta‐analysis included 16 articles of APRI only, 21 articles of APRI and FIB‐4 and two articles of FIB‐4 for detecting different levels of liver fibrosis. With an APRI threshold of 0.5, 1.0, and 1.5, the sensitivity and specificity values were 70.0% and 60.0%, 50.0% and 83.0%, and 36.9% and 92.5% for significant fibrosis, advanced fibrosis, and cirrhosis, respectively. With an FIB‐4 threshold of 1.45 and 3.25, the sensitivity and specificity values were 65.4% and 73.6% and 16.2% and 95.2% for significant fibrosis. The summary AUROC values using APRI and FIB‐4 for the diagnosis of significant fibrosis, advanced fibrosis, and cirrhosis were 0.7407 (95% confidence interval [CI]: 0.7033‐0.7781) and 0.7844 (95% CI: 0.7450‐0.8238; (Z = 1.59, P = 0.06), 0.7347 (95% CI: 0.6790‐0.7904) and 0.8165 (95% CI: 0.7707‐0.8623; Z = 2.01, P = 0.02), and 0.7268 (95% CI: 0.6578‐0.7958) and 0.8448 (95% CI: 0.7742‐0.9154; (Z = 2.34, P = 0.01), respectively. Conclusions: Our meta‐analysis suggests that APRI and FIB‐4 can identify hepatitis B‐related fibrosis with a moderate sensitivity and accuracy. (Hepatology 2015;61:292–302)
Modulation of chemotherapeutic drug resistance in neuroblastoma SK‐N‐AS cells by the neural apoptosis inhibitory protein and miR‐520f
Authors: Harvey Harry , Piskareva Olga , Creevey Laura , Alcock Leah C. , Buckley Patrick G , O'Sullivan Maureen J. , Segura Miguel F. , Gallego Soledad , Stallings Raymond L. , Bray Isabella M.
Published: August 2014

The acquisition of multidrug resistance is a major impediment to the successful treatment of neuroblastoma, a clinically heterogeneous cancer accounting for ∼15% of all pediatric cancer deaths. The MYCN transcription factor, whose gene is amplified in ∼30% of high‐risk neuroblastoma cases, influences drug resistance by regulating a cadre of genes, including those involved with drug efflux, however, other high‐risk subtypes of neuroblastoma lacking MYCN amplification, such as those with chromosome 11q deletions, also acquire multidrug resistance. To elucidate additional mechanisms involved with drug resistance in non‐MYCN amplified tumour cells, an SK‐N‐AS subline (SK‐N‐AsCis24) that is significantly resistant to cisplatin and cross resistant to etoposide was developed through a pulse‐selection process. High resolution aCGH analysis of SK‐N‐AsCis24 revealed a focal gain on chromosome 5 containing the coding sequence for the neural apoptosis inhibitory protein (NAIP). Significant overexpression of NAIP mRNA and protein was documented, while experimental modulation of NAIP levels in both SK‐N‐AsCis24 and in parental SK‐N‐AS cells confirmed that NAIP was responsible for the drug resistant phenotype by apoptosis inhibition. Furthermore, a decrease in the NAIP targeting microRNA, miR‐520f, was also demonstrated to be partially responsible for increased NAIP levels in SK‐N‐AsCis24. Interestingly, miR‐520f levels were determined to be significantly lower in postchemotherapy treatment tumours relative to matched prechemotherapy samples, consistent with a role for this miRNA in the acquisition of drug resistance in vivo, potentially through decreased NAIP targeting. Our findings provide biological novel insight into neuroblastoma drug‐resistance and have implications for future therapeutic research.
SDF‐1α stiffens myeloma bone marrow mesenchymal stromal cells through the activation of RhoA‐ROCK‐Myosin II
Authors: Choi Dong Soon , Stark Daniel J. , Raphael Robert M. , Wen Jianguo , Su Jing , Zhou Xiaobo , Chang Chung‐Che , Zu Youli
Published: August 2014

Multiple myeloma (MM) is a B lymphocyte malignancy that remains incurable despite extensive research efforts. This is due, in part, to frequent disease recurrences associated with the persistence of myeloma cancer stem cells (mCSCs). Bone marrow mesenchymal stromal cells (BMSCs) play critical roles in supporting mCSCs through genetic or biochemical alterations. Previously, we identified mechanical distinctions between BMSCs isolated from MM patients (mBMSCs) and those present in the BM of healthy individuals (nBMSCs). These properties of mBMSC contributed to their ability to preferentially support mCSCs. To further illustrate mechanisms underlying the differences between mBMSCs and nBMSCs, here we report that (i) mBMSCs express an abnormal, constitutively high level of phosphorylated Myosin II, which leads to stiffer membrane mechanics, (ii) mBMSCs are more sensitive to SDF‐1α‐induced activation of MYL2 through the G(i./o)‐PI3K‐RhoA‐ROCK‐Myosin II signaling pathway, affecting Young's modulus in BMSCs and (iii) activated Myosin II confers increased cell contractile potential, leading to enhanced collagen matrix remodeling and promoting the cell–cell interaction between mCSCs and mBMSCs. Together, our findings suggest that interfering with SDF‐1α signaling may serve as a new therapeutic approach for eliminating mCSCs by disrupting their interaction with mBMSCs.
Structural Heterogeneity and Dynamics of the Unfolded Ensemble
Authors: Echeverria Ignacia , Papoian Garegin A.
Published: August 2014

Significant efforts have been devoted to understanding the structural and physicochemical properties of unfolded and intrinsically disordered proteins. Combining experimental measurements with molecular simulations and polymer theory calculations has emerged as a powerful route to accurately characterize the rapidly interchanging conformations of the unfolded ensemble. We review a selection of recent works on the dynamics of unfolded and intrinsically disordered proteins, focusing primarily on computer simulation and theoretical approaches. We use the energy landscapes paradigm to highlight various computational techniques and to outline several directions for future research. One major, immediate challenge is to gain deeper insights into the nature of the energy barriers that determine the roughness of the energy landscape of unfolded proteins. A second important challenge is to better characterize and understand the functional role of partial ordering, or alternatively, disorder‐to‐disorder transitions, between various phases of the unfolded state.
Early response to chemoradiotherapy for nasopharyngeal carcinoma treatment: Value of dynamic contrast‐enhanced 3.0 T MRI
Authors: Zheng Dechun , Chen Yunbin , Liu Xiangyi , Chen Ying , Xu Luying , Ren Wang , Chen Weibo , Chan Queenie
Published: August 2014

Purpose

To prospectively evaluate the dynamic contrast‐enhanced magnetic resonance imaging (DCE‐MRI) value for predicting early nasopharyngeal carcinoma (NPC) chemoradiotherapy (CRT) response.

Materials and Methods

Forty‐two patients with advanced NPC were recruited and received three DCE‐MRI exams before treatment (Pre‐Tx), as well as 3 days (Day 3‐Tx) and 40 days (Day 40‐Tx) after chemotherapy initiation (two neoadjuvant chemotherapy cycles, NAC). We used DCE‐Tool to measure primary tumor kinetic parameters (Ktrans, Kep, ve, and vp) using the extended Tofts model. Kinetic parameters and corresponding changes were compared between responders and nonresponders after NAC or CRT treatment using Student's t or Mann–Whitney U tests.

Results

Response to two NAC cycles correlated with short‐term local control (P = 0.01). Compared to the nonresponder group, the responder group presented with significantly larger ΔKtrans(0–3), ΔKep(0–3), and Δvp(0–3) values after NAC (P < 0.05). The complete response group after CRT exhibited significantly lower Ktrans(Day 40‐Tx) and larger ΔKtrans(0–3) values than the residual group (P = 0.05). High sensitivity (range: 74.1%–90%) and moderate‐to‐high specificity (range: 50%–84.3%) distinguished nonresponders from responders grouping after NAC or CRT, with diagnostic efficiency ranging from 69.3%–88%.

Conclusion

Our study showed kinetic parameter changes earlier after chemotherapy were potential markers for NPC patients receiving CRT therapy following NAC. J. Magn. Reson. Imaging 2015;41:1528–1540. © 2014 Wiley Periodicals, Inc.
HPV and Chlamydia trachomatis co‐detection in young asymptomatic women from high incidence area for cervical cancer
Authors: Bellaminutti Serena , Seraceni Silva , De Seta Francesco , Gheit Tarik , Tommasino Massimo , Comar Manola
Published: August 2014

Chlamydia trachomatis causing chronic inflammatory diseases has investigated as possible human papillomavirus (HPV) cofactor in cervical cancer. The aim of this study is to evaluate the prevalence of Chlamydia trachomatis and HPV co‐infection in different cohorts of asymptomatic women from a Northern Italy area at high incidence for cervical cancer. Cervical samples from 441 females were collected from Cervical Cancer Screening Program, Sexually Transmitted Infectious and Assisted Reproductive Technology centres. HPV and Chlamydia trachomatis were detected simultaneously and genotyped using a highly sensitive bead based assay. The overall prevalence of Chlamydia trachomatis was estimated 9.7%, in contrast with the reported national data of 2.3%, and co‐infection with HPV was diagnosed in the 17% of the samples. In females ≤ 25 years of age, the infection reached a peak of 22% and co‐infection with HPV of 45.8% (P < 0.001). Of note, in young females diagnosed with low grade cervical lesions, no significant difference between Chlamydia trachomatis and HPV distribution was observed, while differently, HPV co‐infection was found significantly associated to the presence of intraepithelial lesions when compared to older females (20% vs. 1%; P < 0.001). In this study, the use of a high sensitive molecular technique exhibited higher analytical sensitivity than the referred assays for the diagnosis of Chlamydia trachomatis and HPV co‐infection in asymptomatic females, leading to reduction of the potential to identify incorrectly the infection status. An active screening for timely treatment of Chlamydia trachomatis infection is suggested in young females to evaluate a possible decrease in incidence of pre‐cancer intraepithelial lesions. J. Med. Virol. 86:1920–1925, 2014. © 2014 Wiley Periodicals, Inc.
Expression of α‐subunit of α‐glucosidase II in adult mouse brain regions and selected organs
Authors: Anji Antje , Miller Hayley , Raman Chandrasekar , Phillips Mathew , Ciment Gary , Kumari Meena
Published: August 2014

α‐Glucosidase II (GII), a resident of endoplasmic reticulum (ER) and an important enzyme in the folding of nascent glycoproteins, is heterodimeric, consisting of α (GIIα) and β (GIIβ) subunits. The catalytic GIIα subunit, with the help of mannose 6‐phosphate receptor homology domain of GIIβ, sequentially hydrolyzes two α1‐3‐linked glucose residues in the second step of N‐linked oligosaccharide‐mediated protein folding. The soluble GIIα subunit is retained in the ER through its interaction with the HDEL‐containing GIIβ subunit. N‐glycosylation and correct protein folding are crucial for protein stability and trafficking and cell surface expression of several proteins in the brain. Alterations in N‐glycosylation lead to abnormalities in neuronal migration and mental retardation, various neurodegenerative diseases, and invasion of malignant gliomas. Inhibitors of GII are used to inhibit cell proliferation and migration in a variety of different pathologies, such as viral infection, cancer, and diabetes. Despite the widespread use of GIIα inhibitory drugs and the role of GIIα in brain function, little is known about its expression in brain and other tissues. Here, we report generation of a highly specific chicken antibody to the GIIα subunit and its characterization by Western blotting and immunoprecipitation using cerebral cortical extracts. By using this antibody, we showed that the GIIα protein is highly expressed in testis, kidney, and lung, with the lowest amount in heart. GIIα polypeptide levels in whole brain were comparable to those in spleen. However, a higher expression of GIIα protein was detected in the cerebral cortex, reflecting its continuous requirement in correct folding of cell surface proteins. © 2014 Wiley Periodicals, Inc.
Phenolic compounds in grains, sprouts and wheatgrass of hulled and non‐hulled wheat species
Authors: Benincasa Paolo , Galieni Angelica , Manetta Anna Chiara , Pace Roberta , Guiducci Marcello , Pisante Michele , Stagnari Fabio
Published: August 2014

BACKGROUND

The use of sprouts and young plantlets in human nutrition is increasing because they often contain phytochemicals and other high value nutrients. This is also the case for wheat, although there is no literature for hulled wheat species. Thus we determined total polyphenols, phenolic acids (PAs), fibre and minerals in grains, 5‐day‐old sprouts and 12‐day‐old wheatgrass of einkorn (cv. Monlis), emmer (cvs Augeo, Rosso Rubino, Zefiro), spelt (cvs Pietro, Giuseppe), durum wheat (cv. Creso) and soft wheat (cv. Orso).

RESULTS

Grains of einkorn and emmer contained twice bound PAs as compared to soft and durum wheat and spelt, with p‐coumaric acid accounting for about 50% of total bound PAs. In wheatgrass, differences between species for bound PAs decreased due to a decrease in einkorn and emmer and an increase in soft and durum wheat. In all species, total phenols and free PAs increased passing from grains to sprouts and wheatgrass. Neutral and acid detergent fibre content increased with sprouting only in einkorn and emmer.

CONCLUSION

Our evidence suggests that the grains of einkorn and emmer and the sprouts and wheatgrass of all Triticum species might potentially be valuable for the development of functional foods. © 2014 Society of Chemical Industry
Stone/tissue differentiation during intracorporeal lithotripsy using diffuse white light reflectance spectroscopy: In vitro and clinical measurements
Authors: Lange Birgit , Jocham Dieter , Brinkmann Ralf , Cordes Jens
Published: August 2014

Background and Objective

Holmium laser lithotripsy is the ‘gold standard’ for intracorporeal fragmentation of stones. However, there is a risk of damaging and perforating the ureter wall when the laser is accidentally fired while the fiber is in contact with tissue. The aim of this study was to evaluate if white illumination light, diffusely reflected back into the treatment fiber and spectrally analyzed, can be used for differentiating between stone and tissue.

Study Design/Materials and Methods

Firstly, in vitro reflectance spectra (Xenon light source, wavelength range λ = 350–850 nm) of 38 human kidney stones, porcine renal calix and ureter tissue were collected. Secondly, in an in vivo study with 8 patients, 72 ureter and 49 stone reflectance signals were recorded during endourological interventions. The spectra were analyzed to discriminate between stone and tissue by the absence or presence of minima due to hemoglobin absorption at λ1 = 542nm and λ3 = 576nm.

Results

In vitro, all stone and tissue signals could correctly be identified by calculating the ratio R = I (λ1 = 542 nm)/I (λ2 = 475 nm): Because of the hemoglobin absorption at λ1, R is smaller for tissue than for calculi. In vivo, only 75% tissue spots could correctly be identified utilizing this method. Using the more sophisticated evaluation of looking for minima in the diffuse reflectance spectra at λ1 = 542 nm and λ3 = 576 nm, 62 out of 64 tissue spots were correctly identified (sensitivity 96.9%). This was also the case for 39 out of 43 stone spots. Taking into account the number of measured spectra, a tissue detection probability of 91% and a stone detection probability of 77% was achieved (significance level 5%).

Conclusion

White light diffusely reflected off the treatment zone into the fiber can be used to strongly improve the safety of Holmium laser lithotripsy by implementing an automatic feedback control algorithm that averts mispositioning the fiber. Lasers Surg. Med. 46:614–619, 2014. © 2014 Wiley Periodicals, Inc.
Characterization of Viscoelasticity and Self‐Healing Ability of VHB 4910
Authors: Fan Fan , Szpunar Jerzy
Published: August 2014

The mechanisms responsible for the viscoelasticity and self‐healing ability of VHB 4910 are studied. The type of chemical bonds is confirmed using Fourier transform infrared and Raman spectroscopy. The tensile tests demonstrate that the material has viscoelastic behavior that depends on the deformation speed and changes in the hysteresis area with different tensile strains. The shear modulus of entangled networks increases with the deformation speed. This behavior confirms that the viscoelasticity is due to the dissociation and re‐association of non‐covalent bonding. The hydrogen bonding initiates the healing process and the diffusion of molecular chains strengthens the self‐healing ability.
Characterization of the Structure, Acoustic Property, Thermal Conductivity, and Mechanical Property of Highly Expanded Open‐Cell Polycarbonate Foams
Authors: Jahani Davoud , Ameli Aboutaleb , Saniei Mehdi , Ding Weidan , Park Chul B. , Naguib Hani E.
Published: August 2014

This paper studies the processing, structural, and property relationships needed for highly expanded open‐cell polycarbonate (PC) foams. Acoustic insulation, thermal conductivity, and mechanical properties of the foams were characterized. Using foam injection molding, samples expansion ratios ranging from 1 to 8 and open‐cell content up to 85% were prepared. Relative to their solid counterparts, the sound wave transmission loss was increased up to 2.5‐fold while their thermal conductivity was decreased up to fivefold. Thus, lightweight rigid PC foams, useful in both sound and thermal insulation applications, were developed.
Two‐dimensional fractal Burgers equation with step‐like initial conditions
Authors: Karch Grzegorz , Pudełko Anna , Xu Xiaojing
Published: August 2014

We consider the two‐dimensional convection–diffusion equation with a fractional Laplacian, supplemented with step‐like initial conditions. We show that the large time behavior of solutions to this IVP is described either by rarefaction waves, or diffusion waves, or suitable self‐similar solutions, depending on the order of the fractional dissipation and on a direction of a convective nonlinearity. Copyright © 2014 John Wiley & Sons, Ltd.
Poly(Urea–Urethane) Synthesis by Miniemulsion Polymerization Using Microwaves and Conventional Polymerization
Authors: Valério Alexsandra , Fortuny Montserrat , Santos Alexandre F. , Araújo Pedro H. H. , Sayer Claudia
Published: August 2014

Microwave irradiation has been an interesting alternative for heating systems of several chemical reactions. In this work, a comparative study between microwave reactions and conventional heating is evaluated. The effects of temperature, power, and polyol type on the synthesis of poly(urea–urethane) by step polymerization in miniemulsion are evaluated and the final polymer is analyzed by Fourier transform infrared spectroscopy, gel permeation chromatography, contact angle, and nanoparticles size and size distribution are characterized by dynamic light scattering. Polymerization under microwave irradiation have a higher reaction rate showing advantages of using microwaves in this miniemulsion step polymerization processes. In addition, microwave irradiation also affects particle size, the solubility of the polyurethane, and the urea/urethane ratio.
A continuum‐discrete model using Darcy's law: formulation and verification
Authors: Goodarzi Majid , Kwok Chung Yee , Tham Leslie George
Published: August 2014

This paper presents a numerical scheme for fluid‐particle coupled discrete element method (DEM), which is based on poro‐elasticity. The motion of the particles is resolved by means of DEM. While within the proposition of Darcian regime, the fluid is assumed as a continuum phase on a Eulerian mesh, and the continuity equation on the fluid mesh for a compressible fluid is solved using the FEM. Analytical solutions of traditional soil mechanics examples, such as the isotropic compression and one‐dimensional upward seepage flow, were used to validate the proposed algorithm quantitatively. The numerical results showed very good agreement with the analytical solutions, which show the correctness of this algorithm. Sensitivity studies on the effect of some influential factors of the coupling scheme such as pore fluid bulk modulus, volumetric strain calculation, and fluid mesh size were performed to display the accuracy, efficiency, and robustness of the numerical algorithm. It is revealed that the pore fluid bulk modulus is a critical parameter that can affect the accuracy of the results. Because of the iterative coupling scheme of these algorithms, high value of fluid bulk modulus can result in instability and consequently reduction in the maximum possible time‐step. Furthermore, the increase of the fluid mesh size reduces the accuracy of the calculated pore pressure. This study enhances our current understanding of the capacity of fluid‐particle coupled DEM to simulate the mechanical behavior of saturated granular materials. Copyright © 2014 John Wiley & Sons, Ltd.
Simulating curvilinear crack propagation in two dimensions with universal meshes
Authors: Rangarajan Ramsharan , Chiaramonte Maurizio M. , Hunsweck Michael J. , Shen Yongxing , Lew Adrian J.
Published: August 2014

We formulate a class of delicately controlled problems to model the kink‐free evolution of quasistatic cracks in brittle, isotropic, linearly elastic materials in two dimensions. The evolving crack satisfies familiar principles—Griffith's criterion, local symmetry, and irreversibility. A novel feature of the formulation is that in addition to the crack path, the loading is also treated as an unknown. Specifically, a scaling factor for prescribed Dirichlet and Neumann boundary conditions is computed as part of the solution to yield an always‐propagating and ostensibly kink‐free crack and a continuous loading history beyond the initial step. A dimensionless statement of the problem depends only on the Poisson's ratio of a homogeneous material, and is in particular, independent of its Young's modulus and fracture toughness.

Numerical resolution of the formulated problem relies on two new ideas. The first is an algorithm to compute triangulations conforming to cracked domains by locally deforming a given background mesh in the vicinity of evolving cracks. The algorithm is robust under mild assumptions on the sizes and angles of triangles near the crack and its smoothness. Hence, a subset, if not the entire family, of cracked domains realized during the course of a simulation can be discretized with the same background mesh; we term the latter a universal mesh for such a family of domains. Universal meshes facilitate adopting a discrete representation for the crack (as splines in our examples), preclude the need for local splitting/retriangulation operations, liberate the crack from following directions prescribed by the mesh, and enable the adoption of standard FEMs to compute the elastic fields in the cracked solid. Second, we employ a method specifically designed to approximate the stress intensity factors for curvilinear cracks. We examine the performance of the resulting numerical method with detailed examples, including comparisons with an exact solution of a crack propagating along a circular arc (which we construct) and comparisons with experimental fracture paths. In all cases, we observe convergence of computed paths, their derivatives, and loading histories with refinement of the universal mesh. Copyright © 2014 John Wiley & Sons, Ltd.