bluuebunny/crossref_metadata_2025_split huggingface dataset:
Calpain‐2 protects against heat stress‐induced cardiomyocyte apoptosis and heart dysfunction by blocking p38 mitogen‐activated protein kinase activation
Authors: Liu Zhi‐feng , Ji Jing‐jing , Zheng Dong , Su Lei , Peng Tianqing 
Published: November 2018

AbstractCardiovascular dysfunction is a common complication among heatstroke patients, but its underlying mechanism is unclear. This study was designed to investigate the role of calpain‐2 and its downstream signal pathway in heat stress‐induced cardiomyocyte apoptosis and heart dysfunction. In cultured primary mouse neonatal cardiomyocytes (MNCs), heat stress (43°C for 2 hr) induced a heat‐shock response, as indicated by upregulated heat‐shock protein 27 (HSP27) expression and cellular apoptosis, as indicated by increased caspase‐3 activity, DNA fragmentation and decreased cell viability. Meanwhile, heat stress decreased calpain activity, which was accompanied by downregulated calpain‐2 expression and increased phosphorylation of p38, extraceIIuIar signaI‐reguIated protein kinase (ERK1/2) and c‐Jun N‐terminaI kinase (JNK). Calpain‐2 overexpression abrogated heat stress‐induced apoptosis and phosphorylation of p38 and JNK, but not of ERK1/2. Blocking only p38 prevented heat stress‐induced apoptosis in MNCs. In cardiac‐specific calpain‐2 overexpressing transgenic mice, p38 phosphorylation and cardiomyocyte apoptosis were decreased in the heart tissue of heatstroke mice, as revealed by western blot and terminal deoxynucleotidyl transferase dUTP nick end labelling assays, respectively. M‐mode echocardiography also demonstrated that calpain‐2 overexpression significantly improved heatstroke‐induced decreases in ventricular end‐diastolic volume and cardiac output. In conclusion, our study suggests that heat stress reduces calpain‐2 expression, which then activates p38, leading to cardiomyocyte apoptosis and heart dysfunction.
Correlation between histological findings and endoscopic findings in patients with ulcerative colitis: Basal plasmacytosis is an important finding suggesting active inflammation
Authors: Mitsuishi Takehiro 
Published: November 2018

AimsIn clinical practice, patients of ulcerative colitis showing divergence between the histological findings and endoscopic findings are often encountered. Therefore, we compared histological findings with endoscopic findings, indicating the severity of the inflammation of ulcerative colitis.Methods and ResultsThe study group comprised 191 patients (527 biopsy specimens) with ulcerative colitis who underwent lower gastrointestinal endoscopy with biopsy in our hospital from July 2015 to June 2016. Endoscopic findings of the mucosa at the biopsy site were classified into seven levels according to the severity of inflammation: noninflamed mucosa, red signs, loss of visible vascular patterns, granular mucosa, friable mucosa, spontaneous bleeding, and erosions/ulcers (E/U). All biopsy samples were examined for the presence or absence of five histological findings (basal plasmacytosis [BP], neutrophil infiltration, cryptitis, crypt abscess [CAb], and E/U), and the results were contrasted with endoscopic findings. The 191 patients comprised 123 (64.4%) males and 68 (35.6%) females, with a median age of 47 years (range, 8–82). Among the 527 specimens, the detection rates of BP, CAb, and E/U in mucosa with endoscopic E/U were 58.5, 27.4, and 18.3%. The detection rate of BP in mucosa with red signs was 22.4%; in mucosa, with loss of visible vascular patterns, it was 16.9%; in granular mucosa, it was 35.7%, and in mucosa with E/U, it was 58.5%. BP was frequently seen in severely inflamed mucosa associated with E/U on endoscopic examination.ConclusionBP was considered an important finding, suggesting the presence of active and severe inflammation.
Demarcation of reaction effects on laminar burning velocities of diluted syngas–air mixtures at elevated temperatures
Authors: Varghese Robin John , Kolekar Harshal , Kumar Sudarshan 
Published: November 2018

AbstractLaminar burning velocities of CO2/N2 (60%, 70%) diluted H2/CO/air mixtures were measured at elevated temperatures using the externally heated diverging channel method. The computed burning velocities using the two reaction mechanisms (Davis et al., Proc. Combust. Inst. 2005;30(1):1283–1292; FFCM‐1, http://nanoenergy.stanford.edu/ffcm1) are compared with the experimentally determined burning velocities. The accuracy of the chemical kinetic mechanisms at high dilution rates and elevated temperatures was investigated for various hydrogen fractions in the fuel composition. The burning velocity is observed to increase at high temperatures due to higher mixture enthalpy. The dilution effect on the variation of laminar burning velocity was stronger for the CO2 dilution case compared to N2 dilution. A comparison between the FFCM‐1 mechanism and experimental measurements shows an accurate depiction of the reaction chemistry regarding the prediction of laminar burning velocities. The role of third‐body reactions and direct inhibiting effect of N2 and CO2 molecules on burning velocity of diluted syngas–air mixtures is analyzed in detail. Detailed kinetic analysis revealed that the use of GRI 3.0 collision efficiency factors in the Davis mechanism helps in accurately predicting the burning velocities at elevated temperatures and high CO2 dilution rates. The thermal effect dominates the reduction in laminar burning velocity for N2 dilution case. The FFCM‐1 mechanism agrees well with the experiments for syngas flames diluted with N2 compared to the Davis mechanism. The addition of third‐body efficiency of N2 in the FFCM‐1 mechanism improved the predictions of laminar burning velocities for the N2 dilution case.
Fabrication and Characterization of Recombinant Silk‐Elastin‐Like‐Protein (SELP) Fiber
Authors: Roberts Erin G. , Rim Nae‐Gyune , Huang Wenwen , Tarakanova Anna , Yeo Jingjie , Buehler Markus J. , Kaplan David L. , Wong Joyce Y. 
Published: November 2018

AbstractSilk‐elastin‐like‐protein polymers (SELPs) are genetically engineered recombinant protein sequences consisting of repeating units of silk‐like and elastin‐like blocks. By combining these entities, it is shown that both the characteristic strength of silk and the temperature‐dependent responsiveness of elastin can be leveraged to create an enhanced stimuli‐responsive material. It is hypothesized that SELP behavior can be influenced by varying the silk‐to‐elastin ratio. If the responsiveness of the material at different ratios is significantly different, this would allow for the design of materials with specific temperature‐based swelling and mechanical properties. This study demonstrates that SELP fiber properties can be controlled via a temperature transition dependent on the ratio of silk‐to‐elastin in the material. SELP fibers are experimentally wet spun from polymers with different ratios of silk‐to‐elastin and conditioned in either a below or above transition temperature (T
t) water bath prior to characterization. The fibers with higher elastin content showed more stimuli‐responsive behavior compared to the fibers with lower elastin content in the hot (57–60 °C) versus cold (4–7 °C) environment, both computationally and experimentally. This work builds a foundation for developing SELP materials with well‐characterized mechanical properties and responsive features.
Functional Silica and Carbon Nanocomposites Based on Polybenzoxazines
Authors: Mohamed Mohamed Gamal , Kuo Shiao Wei 
Published: November 2018

AbstractThe preparation of organic/inorganic hybrid materials comprising a polybenzoxazine (PBZ) matrix incorporating silicon‐based species (e.g., polydimethylsiloxane [PDMS], layered silicates [clays], and polyhedral oligomeric silsesquioxanes [POSS]) and carbon‐based materials (e.g., carbon black, carbon fibers, carbon nanotubes, and graphene) has received much attention in recent years because these composites display low water absorption, low surface free energy, low dielectric constants, flame‐retardancy, and excellent thermal and mechanical properties. This short review article describes the chemical and physical approaches that are used to prepare PBZs incorporating silica and carbon nanocomposites. In addition, recent reports of their physical properties are discussed, covering their dielectric constants and dynamic mechanical, thermal, electrical, and surface properties.
Human‐Iris‐Like Aperture and Sphincter Muscle Comprising Hyperelastic Composite Hydrogels Containing Graphene Oxide
Authors: Kim Seo Gyun , Kim Dowan , Kim Sorie , Yoon Jinhwan , Lee Heon Sang 
Published: November 2018

AbstractSoft hydrogels are extensively studied for developing human‐body‐mimicking actuators because of their stimuli‐responsive volume change and elasticity. Mimicking a human eye with hydrogels is very challenging because both the large variation in the volume and the high modulus of the gels should be concurrently achieved. In the human eye, adjusting the iris for controlling the focal point and light transmittance is achieved by the contraction of the sphincter muscle. In this work, a hyperelastic poly(N‐isopropylacrylamide) containing graphene oxide (PNIPAm/GO) composite hydrogels, which exhibits a thermo‐responsive volume phase transition is developed. The fact that the inner hole size for center‐cut hydrogels can increase or decrease during heating depending on the geometry of the hydrogels is revealed. Based on these findings, human‐iris‐like actuators capable of controlling the shape of a polydimethylsiloxane (PDMS) lens for adjusting magnification of an object is developed. When heated, the hyperelastic hydrogels act like the sphincter muscle in the eye, inducing the curvature change of the attached PDMS lens. Thus, hyperelastic hydrogels of large variation can provide an efficient platform to fabricate various soft actuation systems.
Tailoring Hydrocarbon Polymers and All‐Hydrocarbon Composites for Circular Economy
Authors: Hees Timo , Zhong Fan , Stürzel Markus , Mülhaupt Rolf 
Published: November 2018

AbstractThe world population will rapidly grow from 7 to 9 billion by 2050 and this will parallel a surging annual plastics consumption from today's 350 million tons to well beyond 1 billion tons. The switch from a linear economy with its throwaway culture to a circular economy with efficient reuse of waste plastics is therefore mandatory. Hydrocarbon polymers, accounting for more than half the world's plastics production, enable closed‐loop recycling and effective product‐stewardship systems. High‐molar‐mass hydrocarbons serve as highly versatile, cost‐, resource‐, eco‐ and energy‐efficient, durable lightweight materials produced by solvent‐free, environmentally benign catalytic olefin polymerization. Nanophase separation and alignment of unentangled hydrocarbon polymers afford 100% recyclable self‐reinforcing all‐hydrocarbon composites without requiring the addition of either alien fibers or hazardous nanoparticles. Recycling of durable hydrocarbons is far superior to biodegradation. The facile thermal degradation enables liquefaction and quantitative recovery of low molar mass hydrocarbon oil and gas. Teamed up with biomass‐to‐liquid and carbon dioxide‐to‐fuel conversions, powered by renewable energy, waste hydrocarbons serve as renewable hydrocarbon feedstocks for the synthesis of high molar mass hydrocarbon materials. Herein, an overview is given on how innovations in catalyst and process technology enable tailoring of advanced recyclable hydrocarbon materials meeting the needs of sustainable development and a circular economy.
Mechanoresponsive, Luminescent Polymer Blends Based on an Excimer‐Forming Telechelic Macromolecule
Authors: Calvino Céline , Sagara Yoshimitsu , Buclin Véronique , Haehnel Alexander P. , del Prado Anselmo , Aeby Christian , Simon Yoan C. , Schrettl Stephen , Weder Christoph 
Published: November 2018

AbstractA well‐known approach toward mechanochromic polymers relies on the incorporation of excimer‐forming fluorophores into a matrix polymer and the disruption of aggregated chromophores when such materials undergo macroscopic mechanical deformation. However, the required aggregates and stress‐transfer processes have so far only been realized with select dye/polymer combinations. As demonstrated here, the utility of this approach can be extended by tethering an excimer‐forming cyano‐substituted oligo(p‐phenylene vinylene) fluorophore to the two ends of a telechelic poly(ethylene‐co‐butylene) and blending small amounts (0.1–2 wt%) of the resulting aggregachromic macromolecule into polymer matrices such as poly(ε‐caprolactone), poly(isoprene), or poly(styrene‐b‐butadiene‐b‐styrene). All blends display mechanofluorochromic responses, and the ratio between the monomer and excimer emission intensities can be used to correlate the luminescence signal to the extent of deformation and to follow subsequent relaxation processes. The developed approach significantly expands the scope of blend‐based mechanoresponsive luminescent materials.
Dynamic genome and transcriptional network‐based biomarkers and drugs: precision in breast cancer therapy
Authors: Kyrochristos Ioannis D. , Ziogas Demosthenes E. , Roukos Dimitrios H. 
Published: November 2018

AbstractDespite remarkable progress in medium‐term overall survival benefit in the adjuvant, neoadjuvant and metastatic settings, with multiple recent targeted drug approvals, acquired resistance, late relapse, and cancer‐related death rates remain challenging. Integrated technological systems have been developed to overcome these unmet needs. The characterization of structural and functional noncoding genome elements through next‐generation sequencing (NGS) systems, Hi‐C and CRISPR/Cas9, as well as computational models, allows for whole genome and transcriptome analysis. Rapid progress in large‐scale single‐biopsy genome analysis has identified several novel breast cancer driver genes and oncotargets. The exploration of spatiotemporal tumor evolution has returned exciting while inconclusive data on dynamic intratumor heterogeneity (ITH) through multiregional NGS and single‐cell DNA/RNA sequencing and circulating genomic subclones (cGSs) by serial circulating cell‐free DNA NGS to predict and overcome intrinsic and acquired therapeutic resistance. This review discusses reliable breast cancer genome analysis data and focuses on two major crucial perspectives. The validation of ITH, cGSs, and intrapatient genetic/genomic heterogeneity as predictive biomarkers, as well as the valid discovery of novel oncotargets within patient‐centric genomic trials, encouraging early drug development, could optimize primary and secondary therapeutic decision‐making. A longer‐term goal is to identify the individualized landscape of both coding and noncoding key mutations. This progress will enable the understanding of molecular mechanisms perturbating regulatory networks, shaping the pharmaceutical controllability of deregulated transcriptional biocircuits.
Triple band ultrathin polarization insensitive metamaterial absorber for defense, explosive detection and airborne radar applications
Authors: Dhillon Amarveer Singh , Mittal Divesh , Bargota Rajkiran 
Published: November 2018

AbstractWe demonstrate an ultrathin polarization insensitive metamaterial‐based Concentric Closed Circular Ring Resonator (CCCRR) perfect absorber for explosive detection, bolometer, indoor radar clear applications, thermal detection, defense applications, airborne and surveillance radar signal absorption applications. The unit cell incorporates three concentric closed circular ring resonators. A parametric optimization has been carried out in order to obtain three discrete absorption peaks at 5.57 GHz, 7.969 GHz, and 13.44 GHz exhibiting absorption intensities of 98.87%, 97.99%, and 99.28%, respectively. Owing to the geometrical symmetry, the structure is polarization insensitive for both TE and TM polarizations and has significant absorbance over a wide angle of incidence of 45° for TE and 75° for TM polarizations. The structure is very compact with physical dimensions of 0.185λo*0.185λo *0.01λo, λo is wavelength corresponding to lower absorption peak. The thickness of the proposed structure is λo/100, evidencing the ultrathin characteristic of the proposed structure. The insight of absorption mechanism has been illustrated by analyzing the electric field distribution, power loss density, and normalized impedance. An extensive parametric analysis has been exercised to examine the influence of parametric alterations.
Characterization of a plastic scintillating detector for the Small Animal Radiation Research Platform (SARRP)
Authors: Johnstone Christopher Daniel , Therriault‐Proulx François , Beaulieu Luc , Bazalova‐Carter Magdalena 
Published: November 2018

PurposeThe purpose of this study was to characterize a small plastic scintillator developed for high resolution, real‐time dosimetry of therapy and imaging x‐ray beams delivered by an image‐guided small animal irradiator.Materials and MethodsA 1 mm diameter, 1 mm long polystyrene BCF‐60 scintillating fiber dosimeter was characterized with 220 kVp therapy and 40, 50, 60, 70, and 80 kVp imaging beams on the Small Animal Research Platform (SARRP). Scintillator output, sensitivity (charge per unit dose), linearity, and 0.2‐mm resolution beam profile measurements were performed. A validated in‐house Monte Carlo (MC) model of the SARRP was used to compute detailed energy spectra at locations of dosimetry, and validated scintillator measurement with MC simulations. Mass energy‐absorption coefficients from the National Institute of Standards and Technology (NIST) tables convolved with MC‐derived spectra were used in conjunction with Birks ionization quenching factors to correct scintillator output. An air kerma calibration method was employed to correct scintillator output for in‐air beam profile measurements with open, 5 × 5, and 3 × 3 mm2 square field sizes, and compared to MC simulations.ResultsScintillator dose response showed excellent linearity (R2 ≥ 0.999) for all sensitivity measurements, including output as a function of tube current. Detector sensitivity was 2.41 μC Gy−1 for the 220 kVp therapy beam, and it ranged from 1.21 to 1.32 μC Gy−1 for the 40–80 imaging beams. Percentage difference in sensitivity between the therapy and imaging beams before sensitivity correction and after using the Birks quenching factors were 52.3% and 10.2%, respectively. Percentage differences between the therapy and imaging beam sensitivities after using the air kerma calibration method for in‐air measurements was excellent and below 0.3%. In‐air beam profile measurements agreed to MC simulations within a mean difference of 2.4% for the 5 × 5 and 3 × 3 mm2 field sizes, however, the scintillator showed signs of volume averaging at the penumbra edges.ConclusionsA small plastic scintillator was characterized for therapy and imaging energies of a small animal irradiator, with output corrected for using an in‐house MC model of the irradiator. The characterization of the scintillator detector system for small fields presents steps toward implementing real‐time measurements for quality assurance and small animal treatment and imaging dose verification.
A hybrid quasicontinuum method
Authors: Kavalur Aditya , Kim Woo Kyun 
Published: November 2018

SummaryQuasicontinuum (QC) is a partitioned‐domain multiscale method where the full‐atomistic description is retained in highly deformable subdomains while the energy in the remaining region is approximated using a continuum constitutive relation called the Cauchy‐Born (CB) rule. While the CB rule can capture the full nonlinearity of the strain energy, its computational cost is one or two orders of magnitude higher than the linear elasticity (LE) constitutive relation. In this paper, we propose an extension to the QC method, referred to as “hybrid QC,” where both the CB and LE relations are combined to increase the efficiency of the original QC method. This extension is summed up to a two‐step process. First, the continuum region is further divided into subregions with CB being restricted to subregions adjoining the atomistic region while LE is adopted in the remaining subregions. Second, a corrective scheme is applied to the LE subregion to recover the higher‐order accuracy. The hybrid QC method is validated through two examples: (i) a crystal containing a dipole of Lomer dislocations and (ii) a nanoindentation system. The simulation results show that the proposed hybrid QC method is numerically more efficient than the original QC method while maintaining virtually the same accuracy.
Magnetic field effect on the oxidation of organic substances by molecular oxygen
Authors: Pliss Evgeny M. , Grobov Aleksey M. , Kuzaev Anton K. , Buchachenko Anatoly L. 
Published: November 2018

AbstractMagnetic field effect (ME) on certain steps of chain oxidation of organic compounds of different series by molecular oxygen in liquid phase (initiation, chain propagation, and termination) is presented as a function of [O2] in two regimes. At low concentration of oxygen (<1.5 mM), magnetic field accelerates oxidation by 10% to 100%, but at high concentration no magnetic effect is detected. The dominating contribution into the magnetic effect (ME) is provided by reaction of alkyl radicals to oxygen: R• + O2 → RO2•. This reaction is stimulated by the Zeeman interaction which transforms in the encounter pair (R• O2) producing transformation of quartet spin state, which is spin forbidden to react, into the doublet spin state, which is spin allowed. At high concentration of oxygen, this reaction is not a limiting step and provides no magnetic effect on the total rate of oxidation.
Cellular density‐dependent increases in HIF‐1α compete with c‐Myc to down‐regulate human EP4 receptor promoter activity through Sp‐1‐binding region
Authors: Seira Naofumi , Yamagata Kazuyuki , Fukushima Keijo , Araki Yumi , Kurata Naoki , Yanagisawa Naoki , Mashimo Masato , Nakamura Hiroyuki , Regan John W. , Murayama Toshihiko , Fujino Hiromichi 
Published: November 2018

AbstractThe up‐regulated expression of E‐type prostanoid (EP) 4 receptors has been implicated in carcinogenesis; however, the expression of EP4 receptors has also been reported to be weaker in tumor tissues than in normal tissues. Indeed, EP4 receptors have been suggested to play a role in the maintenance of colorectal homeostasis. This study aimed to examine the underlying mechanisms/reasons for why inconsistent findings have been reported regarding EP4 receptor expression levels in homeostasis and carcinogenesis by focusing on cellular densities. Thus, the human colon cancer HCA‐7 cells, which retain some functional features of normal epithelia, and luciferase reporter genes containing wild‐type or mutated EP4 receptor promoters were used for elucidating the cellular density‐dependent mechanisms about the regulation of EP4 receptor expression. In silico analysis was also utilized for confirming the relevance of the findings with respect to colon cancer development. We here demonstrated that the expression of EP4 receptors was up‐regulated by c‐Myc by binding to Sp‐1 under low cellular density conditions, but was down‐regulated under high cellular density conditions via the increase in the expression levels of HIF‐1α protein, which may pull out c‐Myc and Sp‐1 from DNA‐binding. The tightly regulated EP4 receptor expression mechanism may be a critical system for maintaining homeostasis in normal colorectal epithelial cells. Therefore, once the system is altered, possibly due to the transient overexpression of EP4 receptors, it may result in aberrant cellular proliferation and transformation to cancerous phenotypes. However, at the point, EP4 receptors themselves and their mediated homeostasis would be no longer required.