bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mixture toxicity of nickel and zinc to Daphnia magna is noninteractive at low effect sizes but becomes synergistic at high effect sizes
Authors: Nys Charlotte , Asselman Jana , Hochmuth Jennifer D. , Janssen Colin R. , Blust Ronny , Smolders Erik , De Schamphelaere Karel A.C. 
Published: January 2015

Abstract

To incorporate metal mixture toxicity effects into risk-assessment procedures, more information is needed about combined and interactive effects of metal mixtures during chronic exposure. The authors investigated the toxicity of binary Ni–Zn mixtures in 2 independent full-factorial experiments using standard chronic (21-d) Daphnia magna reproduction toxicity tests. Global statistical analysis (i.e., when considering all investigated mixture treatments simultaneously) showed noninteractive effects according to the concentration addition model and significant synergistic effects according to the independent action model. However, treatment-specific statistical analysis revealed that both occurrence and type of interactive effect were dependent on the effect size at which Ni and Zn were combined in the mixture. Only noninteractive or weakly antagonistic effects occurred in mixture treatments in which each of the individual metals produced only weak adverse effects on its own (i.e., ≤20% reduction of reproductive performance). On the other side of the spectrum, synergistic mixture effects occurred in all mixture treatments where both metals already caused a  &gt; 20% (for independent action) and a  &gt; 40% (for concentration addition) effect on reproduction on their own. Because low effect sizes are the most relevant in most regulatory frameworks, the authors' data suggest that the concentration addition and independent action mixture toxicity models can both serve as conservative models for predicting effects of Ni–Zn mixtures. The present study highlights the importance of investigating metal mixture toxicity at low effect sizes and warns against extrapolating conclusions about metal mixture interactions from high to low effect sizes. Environ Toxicol Chem 2015;34:1091–1102. © 2015 SETAC
Electrode Performances of Amorphous Molybdenum Oxides of Different Molybdenum Valence for Lithium‐ion Batteries
Authors: Jang Jihyun , Kim Sang‐Mo , Kim Youngjin , Park Kern H. , Ku Jun H. , Ryu Ji Heon , Oh Seung M. 
Published: January 2015

AbstractAmorphous molybdenum oxides are prepared by a reduction of Mo6+ aqueous solution with KBH4. Two molybdenum oxides that differ in the average Mo valence are obtained by changing the solution pH, and their electrode performance is compared with each other. The X‐ray absorption spectroscopy and thermogravimetric analysis illustrate that the sample prepared at the higher pH (4.0) shows an Mo valence of +5.5, which is close to that for MoO3, whereas the Mo valence (+4.4) for the other sample, prepared at the lower pH (0.8), is close to that for MoO2. The latter electrode outperforms the former with respect to cycle retention. The former electrode is lithiated by a conversion reaction, which is the case for MoO3. This electrode exhibits a larger initial capacity, but poorer cycle performance, due to massive volume change and repeated metal‐oxygen bond breaking/formation with cycling. The other electrode, the Mo valence, which is +4.4, is lithiated by an addition reaction, in which Li+ ions are stored in structural defects, such as vacancies and void spaces. The superior cycle performance of this electrode can be ascribed to the absence of massive volume change and bond breaking/formation.
Lewis Pair Polymerization of Acrylic Monomers by N‐Heterocyclic Carbenes and B(C6F5)3
Authors: Chen Jiawei , Chen Eugene Y.‐X. 
Published: January 2015

AbstractThis work has uncovered the first highly active and efficient Lewis pair polymerization (LPP) system based on N‐heterocyclic carbene (NHC)/B(C6F5)3 pairs for converting acrylic monomers into medium‐ to high‐molecular weight polymers. The study has systematically examined steric and electronic effects of three 1,3‐dialkyl(Me, iPr, tBu)imidazol‐2‐ylidene NHCs on the LPP of three classes of acrylic monomers, including linear methyl methacrylate (MMA), cyclic biorenewable γ‐methyl‐α‐methylene‐γ‐butyrolactone (γMMBL), and difunctional allyl methacrylate (AMA). For MMA polymerization, IiPr is not only the most active (∼3× and ∼120× more active than IMe and ItBu, respectively), but also the most effective NHC, especially under low NHC loading conditions. Kinetic results are consistent with a bimolecular, activated monomer propagation mechanism. In the case of the more reactive γMMBL, the polymerization by NHC/B(C6F5)3 in CH2Cl2 is extremely rapid, with all three NHCs achieving quantitative monomer conversion in 1 min and thus reaching a high turnover frequency of≥48,000 h−1. The molecular weight (MW) of PγMMBL can be tuned by adjusting the [γMMBL]/[NHC] ratio, and thus high MW polymers with relatively narrow MW distributions can be readily synthesized (e.g., from Mn=1.41×105 g mol−1, Đ=1.08 to Mn=4.89×105 g mol−1, Đ=1.20). The LPP by NHC/B(C6F5)3 is completely chemoselective, as demonstrated by the polymerization of AMA, which selectively polymerizes the conjugated vinyl group while leaving the non‐conjugated vinyl group in the allyl moiety intact, thanks to its activated monomer propagation mechanism. The resulting PAMA is syndiotactic (rr=83 %), uncross‐linked, and soluble in common solvents, thus suitable for further functionalization. This quantitatively chemoselective polymerization by NHC/B(C6F5)3 should provide a facile, yet powerful, approach to functional acrylic polymers.
Quantitative evaluation of the pulmonary microdistribution of TiO2 nanoparticles using X‐ray fluorescence microscopy after intratracheal administration with a microsprayer in rats
Authors: Zhang Guihua , Shinohara Naohide , Kano Hirokazu , Senoh Hideki , Suzuki Masaaki , Sasaki Takeshi , Fukushima Shoji , Gamo Masashi 
Published: January 2015

AbstractThe unevenness of pulmonary nanoparticle (NP) distribution, which hinders the establishment of an absolute dose–response relationship, has been described as one of the limitations of intratracheal administration techniques for toxicological assessment of inhaled NPs. Quantification of the NP microdistribution would facilitate the establishment of a concentration–response relationship in localized regions of the lung; however, such quantitative methods have not been reported. Here, we established a quantitative method for evaluating pulmonary TiO2 NP microdistribution in rats using X‐ray fluorescence microscopy. Ti intensity in lung sections from rats intratracheally administered 10 mg kg–1 TiO2 NPs with a microsprayer was measured using X‐ray fluorescence with a 100 µm beam size. Ti reference samples were prepared by dropping different concentrations of Ti solutions on glass slide or lung sections of untreated rat. Ti intensity increased linearly with Ti content in the reference samples on both substrates. The detection limit of TiO2 was estimated to be 6.3 ng mm–2. The reproducibility was confirmed for measurements done in the short‐ (2 weeks) and long‐term (6 months). The quantitative results of TiO2 NP microdistribution suggested that more TiO2 NPs were distributed in the right caudal and accessory lobes, which are located downstream of the administration direction of the NP suspension, and the lower portion of each lobe. The detection rates of TiO2 NPs were 16.6–25.0%, 5.19–15.6%, 28.6–39.2%, 21.4–38.7% and 10.6–23.2% for lung sections from the right cranial, middle, caudal, accessory and left lobes, respectively. Copyright © 2015 John Wiley & Sons, Ltd.
Effects of homocysteine on mesenchymal cell proliferation and differentiation during chondrogenesis on limb development
Authors: Bourckhardt Gilian Fernando , Cecchini Manuela Sozo , Ammar Dib , Kobus‐Bianchini Karoline , Müller Yara Maria Rauh , Nazari Evelise Maria 
Published: January 2015

AbstractHigh levels of homocysteine (Hcy) are related to an increased risk of the occurrence of congenital anomalies, including limb defects. However, few evaluations about how toxic levels of Hcy affect limb development have been reported. We investigated whether Hcy can affect the cell cycle proteins and proteins involved in mesenchymal cell differentiation during limb development, in a chicken embryo model. Embryos were treated with 20 µmol d‐l Hcy/50 µl saline at embryonic day 2 and analyzed at embryonic day 6. Untreated control embryos received exclusively 50 µl saline solution. To identify cells in proliferation and cell cycle proteins, as well as Pax1/9 and Sox9 proteins, we performed immunolocalization and flow cytometry analyses using the antibodies anti‐phosphohistone H3, anti‐p53, anti‐p21, anti‐proliferating cell nuclear antigen, anti‐Pax1, anti‐Pax9 and anti‐Sox9. No significant differences in cell proliferation were observed between Hcy‐treated and untreated embryos. We observed a decrease of the proliferating cell nuclear antigen and p21 proteins, both involved in the G1 phase of cell cycle progression. On the other hand, in mesenchymal cells of the limbs, Hcy induces an increase of p53 protein, which can be activated by DNA damage. In cell differentiation, Hcy induced an increase mainly of Pax9 and Sox9 proteins. Our data indicate that the treatment with Hcy changes the mesenchymal cell dynamics during limb development, but does not change the morphology of the cartilage molds. These findings provide information to understand better the cellular basis of the toxicity of Hcy on chondrogenesis during limb development. Copyright © 2015 John Wiley & Sons, Ltd.
Design optimization of a radial functionally graded dental implant
Authors: Ichim Paul I. , Hu Xiaozhi , Bazen Jennifer J. , Yi Wei 
Published: January 2015

AbstractIn this work, we use FEA to test the hypothesis that a low‐modulus coating of a cylindrical zirconia dental implant would reduce the stresses in the peri‐implant bone and we use design optimization and the rule of mixture to estimate the elastic modulus and the porosity of the coating that provides optimal stress shielding. We show that a low‐modulus coating of a dental implant significantly reduces the maximum stresses in the peri‐implant bone without affecting the average stresses thus creating a potentially favorable biomechanical environment. Our results suggest that a resilient coating is capable of reducing the maximum compressive and tensile stresses in the peri‐implant bone by up to 50% and the average stresses in the peri‐implant bone by up to 15%. We further show that a transitional gradient between the high‐modulus core and the low‐modulus coating is not necessary and for a considered zirconia/HA composite the optimal thickness of the coating is 100 µ with its optimal elastic at the lowest value considered of 45 GPa. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 58–66, 2016.
Simultaneous synthesis of treatment effects and mapping to a common scale: an alternative to standardisation
Authors: Ades A. E. , Lu Guobing , Dias Sofia , Mayo‐Wilson Evan , Kounali Daphne 
Published: January 2015

ObjectiveTrials often may report several similar outcomes measured on different test instruments. We explored a method for synthesising treatment effect information both within and between trials and for reporting treatment effects on a common scale as an alternative to standardisationStudy designWe applied a procedure that simultaneously estimates a pooled treatment effect and the “mapping” ratios between the treatment effects on test instruments in a connected network. Standardised and non‐standardised treatment effects were compared. The methods were illustrated in a dataset of 22 trials of selective serotonin reuptake inhibitors against placebo for social anxiety disorder, each reporting treatment effects on between one and six of a total nine test instruments.ResultsRatios of treatment effects on different test instruments varied from trial to trial, with a coefficient of variation of 18% (95% credible interval 11–29%). Standardised effect models fitted the data less well, and standardised treatment effects were estimated with less relative precision than non‐standardised effects and with greater relative heterogeneity.ConclusionSimultaneous synthesis of treatment effects and mapping to a common scale make fewer assumptions than standardising by dividing effects by the sample standard deviation, allow results to be reported on a common scale, and deliver estimates with superior relative precision. © 2015 The Authors. Research Synthesis Methods published by John Wiley & Sons, Ltd.
Impact of polyphenolic components from mulberry on apoptosis of vascular smooth muscle cells
Authors: Chan Kuei‐Chuan , Ho Hsieh‐Hsun , Lin Ming‐Cheng , Huang Chien‐Ning , Huang Hui‐Pei , Wang Chau‐Jong 
Published: January 2015

AbstractBACKGROUNDPrevious studies have shown that mulberry polyphenolic compounds have an anti‐atherosclerotic effect in rabbits. Apoptosis of vascular smooth muscle cells (VSMCs) is the key determinant of the number of VSMCs in remodeling. To examine the effect of mulberry polyphenol extracts (MPEs) on the apoptosis of VSMCs and thus the prevention of atherosclerosis, this study investigated the ability of MPEs to induce apoptosis in vitro and the underlying mechanism.RESULTSIt was found that MPEs initially activated JNK/p38 and p53, which in turn activated both Fas‐ligand and mitochondrial pathways, thereby causing mitochondrial translocation of Bax and a reduction in Bcl‐2. This then triggered the cleavage of procaspases, finally resulting in apoptosis of VSMCs.CONCLUSIONThis study shows that MPEs may suppress atherosclerosis through stimulating apoptosis of VSMCs via activating JNK/p38 and p53 signaling. © 2015 Society of Chemical Industry
In Vitro Platelet Adhesion of PNaAMPS/PAAm and PNaAMPS/PDMAAm Double‐Network Hydrogels
Authors: Zheng Wen Jiang , Liu Zhen Qi , Xu Feng , Gao Jie , Chen Yong Mei , Gong Jian Ping , Osada Yoshihito 
Published: January 2015

Nowadays, tough double‐network (DN) hydrogels have attracted great attention owing to their excellent mechanical properties and good biocompatibility, which give them the potential to be used as blood‐contacting soft tissue prostheses and medical devices. However, the study of platelet adhesion behavior on the surface of DN hydrogels has not been reported yet. In this work, the human platelet adhesion on the surface of poly (sodium 2‐acrylamido‐2‐methyl‐propanesulfonate) PNaAMPS/poly acrylamide (PAAm) and PNaAMPS/poly (N,N′‐dimethylacrylamide) (PDMAAm) DN hydrogels is investigated under static conditions in vitro. The numbers of adherent platelets on PNaAMPS/PAAm and PNaAMPS/PDMAAm hydrogels are 16 ± 7 and 9 ± 8 cells per 104 μm2, respectively, which are far less than 297 ± 41 cells per 104 μm2 on polyethylene terephthalate (PET) and 187 ± 26 cells per 104 μm2 on negatively charged PNaAMPS (4 mol%) hydrogel. The results indicate the excellent antiplatelet performance of DN hydrogels. Moreover, the platelet adhesion mechanism is also discussed. The platelet adhesion is affected by the chemical component, zeta potential, and serum proteins adsorption of the hydrogel.image
Effect of caffeine on intrinsic mechanical properties of normal and malignant hyperthermia‐susceptible muscle
Authors: Metterlein Thomas , Hartung Edmund , Roewer Norbert , Anetseder Martin 
Published: January 2015

ABSTRACTIntroductionMalignant hyperthermia (MH) is a potentially lethal anesthesic complication. Pathological symptoms develop after exposure to triggering substances. It remains uncertain whether cellular alterations pre‐exist. Mechanical properties of isolated muscle bundles were examined before and after exposure to a triggering substance.MethodsWith prior written consent, muscle bundles of 12 MH‐susceptible (MHS) and 56 MH‐nonsusceptible (MHN) individuals were examined before and after exposure to incremental doses of caffeine. Mechanical properties (baseline tension, peak tension, time to peak tension, and relaxation time) were measured. Contraction and relaxation derivatives and contraction–relaxation coupling were calculated and analyzed.ResultsMechanical properties were not different between the groups before caffeine application. Caffeine increased peak tension in both groups and baseline tension only in MHS muscle bundles; relaxation time/derivative and contraction–relaxation coupling were prolonged.ConclusionsCellular changes seen in MH are not pre‐existing. Exposure to triggering substance impairs relaxation in MHS muscle. Muscle Nerve 52: 580–583, 2015
Reflectance analysis on the MOCVD growth of AlN on Si(111) by the virtual interface model
Authors: Ng Tuoh‐Bin , Ewoldt David A. , Shepherd Debra A. , Loboda Mark J. 
Published: January 2015

AbstractThe reflectance‐time profile of AlN‐on‐Si(111) growth by MOCVD as acquired through an in‐situ optical reflectance monitor is analyzed. It is found that, similar to the case of GaN‐on‐sapphire nucleation and growth through the low temperature GaN or AlN buffer layer techniques, the reflectance profile for AlN‐on‐Si also contains information that relate to the growth mechanism, which can then be correlated to the as‐grown material quality. Based on the equations for the Virtual Interface model, a set of 6 parameters can be used to curve‐fit the reflectance traces of AlN growth as acquired by the in‐situ optical monitor. By analyzing a range of 405 nm AlN reflectance‐time data from single layer AlN growth to multilayer AlN/AlGaN/GaN stack grown on Si(111), the “goodness of fit” statistics are found to correlate with material quality metrics such as the XRD (002) rocking curve FWHM for AlN, microscopic morphological roughness of the AlN surface, as well as the resultant wafer bow and curvature for GaN/AlGaN grown on the AlN/Si(111) substrate. The correlations provide useful insight into the desirable mechanism and growth mode for the high temperature MOCVD growth of AlN and GaN on Si(111). When fully established, the technique has the potential of being used as an in‐situ pass/fail screen for the MOCVD growth of GaN‐on‐Si. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Evaluation of boundary‐layer cloud forecasts over the Southern Ocean in a limited‐area numerical weather prediction system usingin situ, space‐borne and ground‐based observations
Authors: Huang Yi , Franklin Charmaine N. , Siems Steven T. , Manton Michael J. , Chubb Thomas , Lock Adrian , Alexander Simon , Klekociuk Andrew 
Published: January 2015

Near‐synchronized in situ, space‐borne (A‐Train) and ground‐based lidar observations are employed to evaluate the boundary‐layer clouds (BLCs) over Tasmania and the adjacent Southern Ocean (SO) simulated by the limited‐area version of Australian Community Climate and Earth System Simulator (ACCESS‐C). Two winter cases featuring BLCs associated with a post‐frontal environment and the leading side of a high‐pressure ridge are studied. Previous studies showed that these synoptic conditions contribute to the largest reflected short‐wave radiation biases simulated over the SO.Results of the simulations suggest that the ACCESS‐C model demonstrates an appreciable level of skill in simulating the macrophysical properties of the BLCs over the SO, generally consistent with the in situ and remote‐sensing observations. However, some notable challenges remain: the area cloud fraction of the marine BLCs is consistently underpredicted; the fine‐scale structure of the marine cumuli is poorly represented in the 4 km grid‐length simulations; the capping inversion over the marine boundary layer is generally too high, associated with the marine BLCs being predicted at the wrong altitude and temperature ranges; the liquid water content (LWC) of the BLCs is underestimated; and the model representation of drizzle production can be too efficient.Sensitivity studies are also conducted to test a newly developed autoconversion microphysics scheme and shear‐dominated planetary boundary‐level (PBL) scheme. These parametrizations show notable improvement in cloud prediction for CASE B (i.e. better area cloud fraction and better average and maximum values of LWC). However, none of these tests is able to improve the simulated marine PBL structure. Overall, the simulated cloud biases are jointly influenced by physical parametrizations, poor representations of large‐scale advection, surface fluxes and subsidence. More substantial observations are needed to improve our understanding of the origins and development of these biases and the relative contribution of these errors to the radiation budget over the SO.
PDA: a privacy‐preserving dual‐functional aggregation scheme for smart grid communications
Authors: Li Chen , Lu Rongxing , Li Hui , Chen Le , Chen Jie 
Published: January 2015

AbstractPrivacy‐preserving aggregation for smart grid communications, which precisely meets the requirement of periodically collecting users' electricity consumption while preserving privacy of each individual user, has been extensively studied in recent years. However, most of existing privacy‐preserving aggregation schemes are only focused on the summation aggregation. In this paper, based on the lattice cryptographic technique, we propose a novel privacy‐preserving dual‐functional aggregation scheme (PDA) for smart grid communications. With our proposed PDA scheme, each individual user just reports one data, then multiple statistic values, that is, mean and variance, of all users can be computed by the data & control center in the smart grid, while the privacy of each individual user can still be protected. Detailed security analyses demonstrate that our proposed PDA scheme is secure and robust. In addition, extensive performance evaluations also show that our proposed PDA scheme is efficient in terms of computational and communication overheads when the number of considered users is within an acceptable range. Copyright © 2015 John Wiley & Sons, Ltd.
Endocrine hormones and local signals during the development of the mouse mammary gland
Authors: Brisken Cathrin , Ataca Dalya 
Published: January 2015

Most of mammary gland development occurs postnatally under the control of female reproductive hormones, which in turn interact with other endocrine factors. While hormones impinge on many tissues and trigger very complex biological responses, tissue recombination experiments with hormone receptor‐deficient mammary epithelia revealed eminent roles for estrogens, progesterone, and prolactin receptor (PrlR) signaling that are intrinsic to the mammary epithelium. A subset of the luminal mammary epithelial cells expresses the estrogen receptor α (ERα), the progesterone receptor (PR), and the PrlR and act as sensor cells. These cells convert the detected systemic signals into local signals that are developmental stage‐dependent and may be direct, juxtacrine, or paracrine. This setup ensures that the original input is amplified and that the biological responses of multiple cell types can be coordinated. Some key mediators of hormone action have been identified such as Wnt, EGFR, IGFR, and RANK signaling. Multiple signaling pathways such as FGF, Hedgehog, and Notch signaling participate in driving different aspects of mammary gland development locally but how they link to the hormonal control remains to be elucidated. An increasing number of endocrine factors are appearing to have a role in mammary gland development, the adipose tissue is increasingly recognized to play a role in endocrine regulation, and a complex role of the immune system with multiple different cell types is being revealed. WIREs Dev Biol 2015, 4:181–195. doi: 10.1002/wdev.172This article is categorized under:

Gene Expression and Transcriptional Hierarchies > Cellular Differentiation
Signaling Pathways > Global Signaling Mechanisms
Signaling Pathways > Cell Fate Signaling