bluuebunny/crossref_metadata_2025_split huggingface dataset:
Estimating B1+ in the breast at 7 T using a generic template
Authors: van Rijssel Michael J. , Pluim Josien P. W. , Luijten Peter R. , Gilhuijs Kenneth G. A. , Raaijmakers Alexander J. E. , Klomp Dennis W. J. 
Published: March 2018

Dynamic contrast‐enhanced MRI is the workhorse of breast MRI, where the diagnosis of lesions is largely based on the enhancement curve shape. However, this curve shape is biased by RF transmit (B1+) field inhomogeneities. B1+ field information is required in order to correct these. The use of a generic, coil‐specific B1+ template is proposed and tested.Finite‐difference time‐domain simulations for B1+ were performed for healthy female volunteers with a wide range of breast anatomies. A generic B1+ template was constructed by averaging simulations based on four volunteers. Three‐dimensional B1+ maps were acquired in 15 other volunteers. Root mean square error (RMSE) metrics were calculated between individual simulations and the template, and between individual measurements and the template. The agreement between the proposed template approach and a B1+ mapping method was compared against the agreement between acquisition and reacquisition using the same mapping protocol.RMSE values (% of nominal flip angle) comparing individual simulations with the template were in the range 2.00‐4.01%, with mean 2.68%. RMSE values comparing individual measurements with the template were in the range8.1‐16%, with mean 11.7%. The agreement between the proposed template approach and a B1+ mapping method was only slightly worse than the agreement between two consecutive acquisitions using the same mapping protocol in one volunteer: the range of agreement increased from ±16% of the nominal angle for repeated measurement to ±22% for the B1+ template.With local RF transmit coils, intersubject differences in B1+ fields of the breast are comparable to the accuracy of B1+ mapping methods, even at 7 T. Consequently, a single generic B1+ template suits subjects over a wide range of breast anatomies, eliminating the need for a time‐consuming B1+ mapping protocol.
Understanding deregulated cellular and molecular dynamics in the haematopoietic stem cell niche to develop novel therapeutics for bone marrow fibrosis
Authors: Gleitz Hélène FE , Kramann Rafael , Schneider Rebekka K 
Published: March 2018

AbstractBone marrow fibrosis is the continuous replacement of blood‐forming cells in the bone marrow with excessive scar tissue, leading to failure of the body to produce blood cells and ultimately to death. Myofibroblasts are fibrosis‐driving cells and are well characterized in solid organ fibrosis, but their role and cellular origin in bone marrow fibrosis have remained obscure. Recent work has demonstrated that Gli1+ and leptin receptor+ mesenchymal stromal cells are progenitors of fibrosis‐causing myofibroblasts in the bone marrow. Genetic ablation or pharmacological inhibition of Gli1+ mesenchymal stromal cells ameliorated fibrosis in mouse models of myelofibrosis. Conditional deletion of the platelet‐derived growth factor (PDGF) receptor‐α (PDGFRA) gene (Pdgfra) and inhibition of PDGFRA by imatinib in leptin receptor+ stromal cells suppressed their expansion and ameliorated bone marrow fibrosis. Understanding the cellular and molecular mechanisms in the haematopoietic stem cell niche that govern the mesenchymal stromal cell‐to‐myofibroblast transition and myofibroblast expansion will be critical to understand the pathogenesis of bone marrow fibrosis in both malignant and non‐malignant conditions, and will guide the development of novel therapeutics. In this review, we summarize recent discoveries of mesenchymal stromal cells as part of the haematopoietic niche and as myofibroblast precursors, and discuss potential therapeutic strategies in the specific targeting of fibrotic transformation in bone marrow fibrosis. © 2018 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.
DNA methylation of microRNA‐coding genes in non‐small‐cell lung cancer patients
Authors: Heller Gerwin , Altenberger Corinna , Steiner Irene , Topakian Thais , Ziegler Barbara , Tomasich Erwin , Lang György , End‐Pfützenreuter Adelheid , Zehetmayer Sonja , Döme Balazs , Arns Britt‐Madeleine , Klepetko Walter , Zielinski Christoph C , Zöchbauer‐Müller Sabine 
Published: March 2018

AbstractDeregulated DNA methylation leading to transcriptional inactivation of certain genes occurs frequently in non‐small‐cell lung cancers (NSCLCs). As well as protein‐coding genes, microRNA (miRNA)‐coding genes may be targets for methylation in NSCLCs; however, the number of known methylated miRNA genes is still small. Thus, we investigated methylation of miRNA genes in primary tumour (TU) samples and corresponding non‐malignant lung tissue (NL) samples of 50 NSCLC patients by using methylated DNA immunoprecipitation followed by custom‐designed tiling microarray analyses (MeDIP‐chip), and 252 differentially methylated probes between TU samples and NL samples were identified. These probes were annotated, which resulted in the identification of 34 miRNA genes with increased methylation in TU samples. Some of these miRNA genes were already known to be methylated in NSCLCs (e.g. those encoding miR‐9‐3 and miR‐124), but methylation of the vast majority of them was previously unknown. We selected six miRNA genes (those encoding miR‐10b, miR‐1179, miR‐137, miR‐572, miR‐3150b, and miR‐129‐2) for gene‐specific methylation analyses in TU samples and corresponding NL samples of 104 NSCLC patients, and observed a statistically significant increase in methylation of these genes in TU samples (p < 0.0001). In silico target prediction of the six miRNAs identified several oncogenic/cell proliferation‐promoting factors (e.g. CCNE1 as an miR‐1179 target). To investigate whether miR‐1179 indeed targets CCNE1, we transfected miR‐1179 gene mimics into CCNE1‐expressing NSCLC cells, and observed downregulated CCNE1 mRNA expression in these cells as compared with control cells. Similar effects on cyclin E1 expression were seen in western blot analyses. In addition, we found a statistically significant reduction in the growth of NSCLC cells transfected with miR‐1179 mimics as compared with control cells. In conclusion, we identified many methylated miRNA genes in NSCLC patients, and found that the miR‐1179 gene is a potential tumour cell growth suppressor in NSCLCs. Overall, our findings emphasize the impact of miRNA gene methylation on the pathogenesis of NSCLCs. © 2018 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.
The isomerization of cytosine: Intramolecular hydrogen atom transfer mediated through formic acid
Authors: Jin Lingxia , Song Xiaoling , Cao Zhe , Luo LiYang , Zhao Caibin , Lu Jiufu , Zhang Qiang 
Published: March 2018

AbstractThe catalytic ability of H2O and HCOOH to facilitate the tautomerism of KA to KIt isomer has been studied. It is shown that the direct tautomerism (path A) is unlikely because of the high activation free energy, whereas the presence of H2O and HCOOH (paths B and C) significantly contributes to decreasing the activation free energy. Meanwhile, the conventional transition state theory followed by Wigner tunneling correction is applied to estimate the rate constants. The rate constant with Wigner tunneling correction for direct tautomerization is obviously smaller than that of HCOOH‐mediated tautomerization, which is the most plausible mechanism. Finally, another important finding is that the ratio of reaction rates between direct tautomerism reaction and catalyst‐induced tautomerism increases with the increase of the catalyst concentration at a given temperature. The results of the present study demonstrate the feasibility of acid catalysis for DNA bases isomerization reaction that would otherwise be forbidden.
Microstructural evolution underlying the ternary stages of the elastic behaviors for poly(ether‐b‐amide) copolymer elastomers
Authors: Zhu Ping , Dong Xia , Huang Miaoming , Wang Lili , Qi Shunxin , Wang Dujin 
Published: March 2018

ABSTRACTThree stages of elastic behavior were observed during cyclic deformations for poly(ether‐b‐amide) (PEBA) segmented copolymers based on crystalline hard segments of polyamide 12 (PA12) and amorphous soft segments of poly(tetramethylene oxide) (PTMO). The underlying microstructural evolution was characterized by a combination of in situ Fourier transform infrared spectroscopy (FTIR), wide‐angle X‐ray diffraction (WAXD), and small‐angle X‐ray scattering (SAXS) technologies. The γ–α″ phase transition of crystalline PA12 occurred upon stretching, and the orientation of the α″ phase was less reversible under larger strains. PTMO chain orientation cannot be restored to the initial state, contributing to plastic deformation. Driven by the entropy effect, the strain‐induced crystallization of PTMO can fuse during sample retarding, exerting little influence on the residual strain. For PEBA with a shore D hardness of 35 D, the long period (L) can be restored to the initial L after the sample was unloaded until system fibrillation. The tie molecules between adjacent oriented lamellae can be by drawn out high stress in a PEBA material with a shore D hardness of 40 D, and the relaxation led to a second long period. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2018, 56, 855–864
Comparative analysis of nanobody sequence and structure data
Authors: Mitchell Laura S. , Colwell Lucy J. 
Published: March 2018

AbstractNanobodies are a class of antigen‐binding protein derived from camelids that achieve comparable binding affinities and specificities to classical antibodies, despite comprising only a single 15 kDa variable domain. Their reduced size makes them an exciting target molecule with which we can explore the molecular code that underpins binding specificity—how is such high specificity achieved? Here, we use a novel dataset of 90 nonredundant, protein‐binding nanobodies with antigen‐bound crystal structures to address this question. To provide a baseline for comparison we construct an analogous set of classical antibodies, allowing us to probe how nanobodies achieve high specificity binding with a dramatically reduced sequence space. Our analysis reveals that nanobodies do not diversify their framework region to compensate for the loss of the VL domain. In addition to the previously reported increase in H3 loop length, we find that nanobodies create diversity by drawing their paratope regions from a significantly larger set of aligned sequence positions, and by exhibiting greater structural variation in their H1 and H2 loops.
The bean α‐amylase inhibitor αAI‐1 in genetically modified chickpea seeds does not harm parasitoid wasps
Authors: Lüthi Christoph , Álvarez‐Alfageme Fernando , Romeis Jörg 
Published: March 2018

AbstractBACKGROUNDLegumes have been genetically engineered to express α‐amylase inhibitor 1 (αAI‐1) from common bean in their seeds. Whereas the genetically modified (GM) seeds are immune to multiple bruchid pest species, the cosmopolitan bruchid Acanthoscelides obtectus is tolerant to αAI‐1 and their larvae develop normally inside the seeds. Hymenopteran bruchid parasitoids, the most important natural enemies of bruchids, might thus be exposed to αAI‐1 when attacking A. obtectus larvae developing inside GM seeds. Exposure might reduce parasitoid fitness, resulting in a decline in the natural control of A. obtectus, and thus promote the spread of this pest. We investigated the impact of the presence of αAI‐1 in legume seeds on parasitoid fitness in tritrophic experiments with αAI‐1 GM or non‐GM chickpea seeds, A. obtectus, and three parasitoid species. Additionally, we investigated the exposure of parasitoids to αAI‐1 using a fourth, highly sensitive parasitoid species.RESULTSParasitoid fitness was not affected when A. obtectus was used in GM chickpea seeds as hosts, and this lack of effects was probably attributable to the fact that exposure of the parasitoids to αAI‐1 was negligible.CONCLUSIONWe conclude that the release of GM chickpeas containing αAI‐1 should not harm this important group of non‐target insects. © 2018 Society of Chemical Industry
Can the salmon bias effect explain the migrant mortality advantage in England and Wales?
Authors: Wallace Matthew , Kulu Hill 
Published: March 2018

AbstractDespite researchers regularly observing a migrant mortality advantage in high‐income destination countries, it remains unclear whether empirically observed low mortality among foreign‐born relative to natives is genuine or a result of censoring and selection biases inherent in the remigration of foreign‐born individuals. Our aim is to determine whether the main mode of selection bias, the “salmon bias effect” (remigration triggered by poor health), can account for this low foreign‐born mortality. We use the largest longitudinal resource in the United Kingdom, the Office for National Statistics Longitudinal Study, to fit discrete‐time survival models and observe which foreign‐born populations experience a migrant mortality advantage and/or salmon bias effect. For foreign‐born groups in which we observe both, we correct their mortality (using an indirect method) to see if the salmon bias can explain the observed mortality advantage. Importantly, we demonstrate that for many foreign‐born groups a mortality advantage exists in the absence of the salmon bias effect. Furthermore, in cases which we observe a mortality advantage and salmon bias (males and females from India, Pakistan and Bangladesh, and the Caribbean), the latter cannot sufficiently “explain away” the former. Taken together with previous findings on censoring bias in the United Kingdom and the wider international literature on censoring and selection biases, it becomes clear that remigration biases alone cannot sufficiently explain the migrant mortality advantage.
Snake‐like surgical forceps for robot‐assisted minimally invasive surgery
Authors: Jin Xingze , Zhao Ji , Feng Mei , Hao Liangtian , Li Qiumeng 
Published: March 2018

AbstractBackgroundSurgical instruments greatly impact the performance of robot‐assisted minimally invasive surgery (RMIS) because they operate on tissues.MethodsA snake‐like surgical instrument, designed with 4 degrees of freedom (DOFs), is proposed for RMIS. The DOFs are as follows: opening and closing motions of the forceps, rotation of the forceps and bi‐directional bending of the instrument. The performance of the instrument was evaluated using a prototype in vitro.ResultsAll DOFs of the instrument were experimentally evaluated and proven sufficient for RMIS. In vitro testing showed that the operations of the proposed model were powerful and steady.ConclusionsThe position and posture of the surgical instrument could be adjusted in the body of the patient by its bending and rotational movements. The proposed model could therefore work as a competent assistant in multi‐port RMIS and allow surgeons to perform better.
Maternal virus infections in pregnancy and type 1 diabetes in their offspring: Systematic review and meta‐analysis of observational studies
Authors: Allen Digby W. , Kim Ki Wook , Rawlinson William D. , Craig Maria E. 
Published: March 2018

SummaryVirus infections are implicated in the development of type 1 diabetes based on epidemiological, clinical, in vitro cell‐based and molecular studies, and animal models. We reviewed the association between virus infections in pregnant women and development of islet autoimmunity or type 1 diabetes in their offspring. We performed a systematic review and meta‐analysis, analysed using random effects models, of human studies from Medline and EMBASE without language restriction. Inclusion criteria were as follows: cohort and case‐control studies measuring viral nucleic acid in blood, stool, urine, or tissue, or serological tests for viruses, in pregnant women whose offspring developed islet autoimmunity and/or type 1 diabetes. All studies required sufficient data to calculate odds ratios and 95% confidence intervals. The 10 studies (4 case control, 6 nested‐case control) that met the eligibility criteria included 2992 participants (953 offspring, 2039 mothers), with varying study design. The 2 outcomes examined were islet autoimmunity (n = 466) and type 1 diabetes (n = 2526). Meta‐analysis showed a significant association between virus infection during pregnancy and clinical type 1 diabetes during childhood (odds ratio 2·16, 95% CI 1·22‐3·80; P = 0·008; heterogeneity X2 = 1·65, I2 = 40%), but no association with islet autoimmunity (1·45, 0·63‐3·31; P = 0·38; X2 = 1·34, I2 = 25%). The increased risk of type 1 diabetes following maternal virus infection is consistent with viraemia involving the fetus during pregnancy and suggests a potential causative link between antenatal infection and type 1 diabetes. Larger prospective birth studies with more frequent sampling, and pathogenesis studies, are required to more clearly establish an aetiological link.
Sequential interfacial reactions of SAC305 solder joints with thin ENEPIG surface finishes
Authors: Yoon Jeong‐Won , Back Jong‐Hoon , Jung Seung‐Boo 
Published: March 2018

Sequential interfacial reactions of Sn‐3.0Ag‐0.5Cu solder on a new multilayer metallization, ENEPIG (electroless nickel‐electroless palladium‐immersion gold) with a 0.1‐μm‐thin Ni(P) layer (thin‐ENEPIG), during reflowing were evaluated in this study. After 20‐second reflow process, layer‐shaped (Au,Cu)Sn4 intermetallic compounds formed at the interface, and thin Ni and Pd layers underneath the Au layer remained unreacted on the polycrystalline Cu substrate. On the other hand, Au, Pd, and Ni tri‐layers in the thin ENEPIG layer were exhausted and (Cu,Ni)6Sn5 intermetallic compounds formed at the interface after reflowing for 30 seconds.
Wrinkling of graphene because of the thermal expansion mismatch between graphene and copper
Authors: Ogurtani Omer Tarik , Senyildiz Dogukan , Cambaz Buke Goknur 
Published: March 2018

Well‐defined bundles of wrinkles are observed on the graphene‐covered copper by using atomic force microscopy after chemical vapor deposition process. Their numerical analyses are performed by employing a set of formula deduced from classical elasticity theory of bent thin films with clamped boundary conditions. Here they are imposed by the banks of trenches associated with the reconstructed copper substrate surfaces, which suppress lateral movements of graphene monolayers and induce local biaxial stress. The wrinkling wavelength (λ) and amplitude (A) are both measured experimentally (λ = 100‐160 nm and A = 2.5‐3 nm) and calculated numerically (λ = 167 nm and A = 3.0 nm) and found to be in good agreement. Wrinkle formation is attributed to the nonhydrostatic compression stresses induced on the graphene by the linear thermal expansion coefficient difference between graphene and copper during cooling. These mismatch stresses, which are varying strongly with the temperature, create temperature‐dependent wrinkling wave formation that decreases in wavelength and increases in amplitude upon cooling below the cross‐over temperature of 1233 K, at which both values of linear thermal expansion coefficient are equal.
Interfacial mutations in the Al‐polyimide system
Authors: Putz B. , Milassin G. , Butenko Y. , Völker B. , Gammer C. , Semprimoschnig C. , Cordill M. J. 
Published: March 2018

Understanding the thermal stability of metal‐polymer interfaces is essential for the reliability of innovative high‐tech devices, including flexible electronics or satellite insulation. In this study, the interfacial stability of aluminum‐polyimide (Al‐PI) is investigated as a function of thermal cycling (±150°C) and thermal annealing treatments (150°C‐300°C) with X‐ray photoelectron spectroscopy measurements performed after peeling and cross‐sectional transmission electron microscopy analysis. Small mutations in the interface chemistry and structure were detected and identified after annealing at 225°C for 140 hours, including the thickness increase of an amorphous interlayer between Al and PI of about 2 nm and a change in the failure mechanism during the peeling. Being able to trace subcritical mutations before they become fatal is essential to predict the reliability and lifetime of metal‐polymer composites.
Adjustable Intermolecular Interactions Allowing 2D Transition Metal Dichalcogenides with Prolonged Scavenging Activity for Reactive Oxygen Species
Authors: Yim DaBin , Kim Ji Eun , Kim Hye‐In , Yang Jin‐Kyoung , Kang Tae‐Woog , Nam Jin , Han Sang Hoon , Jun Byeongsun , Lee Chi Ho , Lee Sang Uck , Kim Jin Woong , Kim Jong‐Ho 
Published: March 2018

AbstractThere is an increasing demand for control over the dimensions and functions of transition metal dichalcogenides (TMDs) in aqueous solution toward biological and medical applications. Herein, an approach for the exfoliation and functionalization of TMDs in water via modulation of the hydrophobic interaction between poly(ε‐caprolactone)‐b‐poly(ethylene glycol) (PCL‐b‐PEG) and the basal planes of TMDs is reported. Decreasing the hydrophobic PCL length of PCL‐b‐PEG from 5000 g mol−1 (PCL5000) to 460 g mol−1 (PCL460) significantly increases the exfoliation efficiency of TMD nanosheets because the polymer–TMD hydrophobic interaction becomes dominant over the polymer–polymer interaction. The TMD nanosheets exfoliated by PCL460‐b‐PEG5000 (460‐WS2, 460‐WSe2, 460‐MoS2, and 460‐MoSe2) show excellent and prolonged scavenging activity for reactive oxygen species (ROS), but each type of TMD displays a different scavenging tendency against hydroxyl, superoxide, and 2,2′‐azino‐bis(3‐ethylbenzothiazoline‐6‐sulfonic acid) radicals. A mechanistic study based on electron paramagnetic resonance spectroscopy and density functional theory simulations suggests that radical‐mediated oxidation of TMDs and hydrogen transfer from the oxidized TMDs to radicals are crucial steps for ROS scavenging by TMD nanosheets. As‐prepared 460‐TMDs are able to effectively scavenge ROS in HaCaT human keratinocytes, and also exhibit excellent biocompatibility.
Bone Marrow-Derived Mesenchymal Stem Cells Protect Islet Grafts Against Endoplasmic Reticulum Stress-Induced Apoptosis During the Early Stage After Transplantation
Authors: He Ying , Zhang Dongmei , Zeng Yi , Ma Junlei , Wang Jing , Guo Hui , Zhang Ji , Wang Mengqin , Zhang Weijie , Gong Nianqiao 
Published: March 2018

Abstract
Early loss of grafted islets is the main obstacle to achieve favorable outcomes of islet transplantation. Mesenchymal stem cells are known to have a protective effect; however, its mechanism remains unclear. We hypothesized that bone marrow-derived mesenchymal stem cells (BMSCs) can protect grafted islets against endoplasmic reticulum stress (ERS)-induced apoptosis. In syngeneic streptozocin-induced diabetic BALB/c mice, islet grafts decreased blood glucose levels; however, the effect was not fully functional from the immediate post-transplant phase. β-Cell apoptosis was proven on days 1 and 3 after transplantation. Ultra-structural evidence of ERS was observed along with increased expressions of marker protein BIP and apoptosis-related protein CHOP. In contrast, BMSC co-transplantation maintained glucose hemostasis, inhibited apoptosis and alleviated ERS. In ex vivo culture, BMSCs improved viability of islets and decreased apoptosis. Increased ERS were observed in cultured islets exposed to hypoxia, but not in the islets cocultured with BMSCs. Furthermore, cocultured BMSCs protected islets against ERS-induced apoptosis as well as improved their insulin secretion, and BMSCs alleviated ERS by improving Myc expression through both stromal cell-derived factor 1 signal and contact effect. In conclusion, BMSCs protected the grafted islets against ERS-induced apoptosis during the early stage after transplantation. This study opens a new arena for ERS-targeted therapy to improve outcomes of islet transplantation.