bluuebunny/crossref_metadata_2025 huggingface dataset:
Four long noncoding RNAs as potential prognostic biomarkers for hepatocellular carcinoma
Authors: Wang Jianchu , Pu Jian , Yao Tianwei , Lu Xiaojie , Deng Yibin
Published: November 2018

The study aimed to identify the long noncoding RNAs (lncRNAs) biomarkers for occurrence and prognosis of patients with hepatocellular carcinoma (HCC), and simultaneously to investigate the potential role of lncRNAs in the oncogenesis of HCC. The lncRNAs expression data and the corresponding clinical information of HCC samples were extracted from The Cancer Genome Atlas (TCGA) database. The differentially expressed genes and lncRNAs were identified and the correlation networks were constructed. In this study, we identified 212 differentially expressed lncRNAs and 7,577 differentially expressed genes between liver HCC tumor tissues and normal tissue samples. And then, combining with clinical information, a total of 11 lncRNAs and 162 genes as HCC biomarkers were identified by comprehensive bioinformatics analysis. Further, through coexpress network analysis, we confirmed four lncRNAs (lncRNA_ANKRD10.IT1, lncRNA_CTD.2583A14.8, lncRNA_RP11.404P21.3, and lncRNA_RP11.488L18.10), which can serve as prognostic biomarkers for HCC. The four lncRNAs identified in this study may serve as a potential therapy target for HCC.
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

Cardiovascular 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

Aims

In 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 Results

The 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.

Conclusion

BP 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

Laminar 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

Silk‐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

The 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

Soft 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

The 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

A 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

Despite 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.
A note on Baskakov‐Kantorovich type operators preserving e−x
Authors: Yılmaz Övgü Gürel , Gupta Vijay , Aral Ali
Published: November 2018

In this paper, we give a generalization of the Baskakov‐Kantorovich type operators that reproduce functions e0 and e−x. We discuss uniform convergence of this generalization by means of the modulus of continuity and establish quantitive asymptotic formula.
H∞ robust control based on event‐triggered sampling for hybrid systems with singular Markovian jump
Authors: Pan Suying , Ye Zhiyong , Zhou Jin
Published: November 2018

The problem of H∞ robust control based on event‐triggered sampling for a class of singular hybrid systems with Markovian jump is considered in this paper. The primary object of this paper here is to design the event‐triggered sampling controller for a class of uncertain singular Markovian systems, and two fundamental issues on mean square exponential admissibility and H∞ robust performance are fully addressed. By making use of a suitable Lyapunov functional, in combination with both infinitesimal operator and linear matrices inequalities(LMIs), the sufficient criteria are derived to guarantee the controlled singular hybrid system with Markovian jump is robustly exponentially mean‐square admissible and has a prescribed H∞ performance γ. Finally, a typical RLC circuit system is given to show the effectiveness of the proposed control method.
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

We 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

Purpose

The 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 Methods

A 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.

Results

Scintillator 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.

Conclusions

A 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

Quasicontinuum (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

Magnetic 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.
Characterization of a non‐thermally operated electrosurgical argon plasma source by electron spin resonance spectroscopy
Authors: Weiss Martin , Utz Raphael , Ackermann Michael , Taran Florin‐Andrei , Krämer Bernhard , Hahn Markus , Wallwiener Diethelm , Brucker Sara , Haupt Michael , Barz Jakob , Oehr Christian
Published: November 2018

Non‐thermal plasma treatment is one of the promising options for local anti‐neoplastic treatment of dysplastic lesions and early intraepithelial cancer. Primarily, the antiproliferative properties are driven through the generation of reactive oxygen and nitrogen species. In this study, we investigated the amount and distribution of reactive species generated by a non‐thermally operated electrosurgical argon plasma source using electron spin resonance (ESR) spectroscopy. During the plasma treatment of both, aqueous solution and solid human preputial tissue an increasing amount of different oxygen‐ and carbon‐centered radicals was detected. However, and most probably due to spin trap degradation by the high energy input and the increase of reactive components in aqueous solution, the ESR signal decreased after treatment times exceeding 10 s.
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

The 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.
Sublethal effects from endosulfan on parasitization by the parasitoid wasp Leptopilina boulardi and specificity of nervous pathways involved
Authors: Delpuech Jean‐Marie
Published: November 2018

Background

Endosulfan is a semi‐permanent pollutant that can be transported long distances through the atmosphere. Although phased out in many countries, it is still used in some highly populated areas and thus greatly contributes to environmental pollution. It can impact non‐target species such as Leptopilina boulardi, a hymenopteran parasitoid that is beneficial because it controls the populations of its host. Only one L. boulardi egg can successfully develop in its host, a Drosophila larva. Consequently, parasitoid females generally lay only one egg per host, except when they are infected by a virus (LbFV) that triggers superparasitization behavior (laying more than one egg per host). The effects of an LC20 of endosulfan on the parasitization behavior of two L. boulardi strains, one infected by LbFV and the other not, were evaluated.

Results

Endosulfan decreased the number of host larvae parasitized by both strains (decreased rate of parasitization) but had no impact on the number of eggs laid per host (i.e., the rate of superparasitization) irrespective of whether the strain was infected by LbFV or not.

Conclusions

Recent research has shown that the organophosphorus insecticide chlorpyrifos induced superparasitization in parasitoid females. Both endosulfan and chlorpyrifos are neurotoxic and induce nervous system hyperstimulation. The fact that endosulfan does not trigger superparasitization, whereas chlorpyrifos does suggests that this effect is due to the specific pathway impacted by chlorpyrifos, the cholinergic nervous pathway. The consequences of these results in the context of awareness of environmental pollution by pesticides are discussed. © 2018 Society of Chemical Industry
RNA interference of muscle actin and ATP synthase beta increases mortality of the phytoplasma vector Euscelidius variegatus
Authors: Abbà Simona , Galetto Luciana , Ripamonti Matteo , Rossi Marika , Marzachì Cristina
Published: November 2018

BACKGROUND

RNA interference (RNAi) techniques have emerged as powerful tools to develop novel management strategies for the control of insect pests. The leafhopper Euscelidius variegatus is a natural vector of chrysanthemum yellows phytoplasma and a laboratory vector of Flavescence dorée phytoplasma. Phytoplasmas are insect‐borne bacterial plant pathogens that cause economically relevant crop losses worldwide.

RESULTS

In this study, we demonstrated that microinjection of muscle actin and ATP synthase β double‐stranded (ds)RNAs into adult insects caused an exponential reduction in the expression of both genes, which began within 72 h of dsRNA administration and lasted for 14 days, leading to almost complete silencing of the target genes. Such silencing effects on muscle actin expression appeared to be both time‐ and dose‐dependent. Our results also showed that the knockdown of both genes caused a significant decrease in survival rates in comparison with green fluorescent protein (GFP) dsRNA‐injected control insects.

CONCLUSION

The effectiveness of RNAi‐based gene silencing in E. variegatus guarantees the availability of a powerful reverse genetic tool for the functional annotation of its genes and the identification of those potentially involved in the interaction with phytoplasmas. In addition, this study demonstrated that muscle actin and ATP synthase β may represent candidate genes for RNAi‐based control of E. variegatus. © 2018 Society of Chemical Industry
A Survey of Software Tool Utilization and Capabilities for Quantitative Systems Pharmacology: What We Have and What We Need
Authors: Ermakov Sergey , Schmidt Brian J. , Musante Cynthia J. , Thalhauser Craig J.
Published: November 2018

Quantitative systems pharmacology (QSP) is a rapidly emerging discipline with application across a spectrum of challenges facing the pharmaceutical industry, including mechanistically informed prioritization of target pathways and combinations in discovery, target population, and dose expansion decisions early in clinical development, and analyses for regulatory authorities late in clinical development. QSP's development has influences from physiologic modeling, systems biology, physiologically‐based pharmacokinetic modeling, and pharmacometrics. Given a varied scientific heritage, a variety of tools to accomplish the demands of model development, application, and model‐based analysis of available data have been developed. We report the outcome from a community survey and resulting analysis of how modelers view the impact and growth of QSP, how they utilize existing tools, and capabilities they need improved to further accelerate their impact on drug development. These results serve as a benchmark and roadmap for advancements to the QSP tool set.
Properties and Bayesian fitting of restricted Boltzmann machines
Authors: Kaplan Andee , Nordman Daniel , Vardeman Stephen
Published: November 2018

A restricted Boltzmann machine (RBM) is an undirected graphical model constructed for discrete or continuous random variables, with two layers, one hidden and one visible, and no conditional dependency within a layer. In recent years, RBMs have risen to prominence due to their connection to deep learning. By treating a hidden layer of one RBM as the visible layer in a second RBM, a deep architecture can be created. RBMs thereby are thought to have the ability to encode very complex and rich structures in data, making them attractive for supervised learning. However, the generative behavior of RBMs largely is unexplored and typical fitting methodology does not easily allow for uncertainty quantification in addition to point estimates. In this paper, we discuss the relationship between RBM parameter specification in the binary case and model properties such as degeneracy, instability and uninterpretability. We also describe the associated difficulties that can arise with likelihood‐based inference and further discuss the potential Bayes fitting of such (highly flexible) models, especially as Gibbs sampling (quasi‐Bayes) methods often are advocated for the RBM model structure.
General Nondestructive Passivation by 4‐Fluoroaniline for Perovskite Solar Cells with Improved Performance and Stability
Authors: Zhao Shenghe , Xie Jiangsheng , Cheng Guanghui , Xiang Yuren , Zhu Houyu , Guo Wenyue , Wang Han , Qin Minchao , Lu Xinhui , Qu Junle , Wang Jiannong , Xu Jianbin , Yan Keyou
Published: November 2018

Hybrid perovskite thin films are prone to producing surface vacancies during the film formation, which degrade the stability and photovoltaic performance. Passivation via post‐treatment can heal these defects, but present methods are slightly destructive to the bulk of 3D perovskite due to the solvent effect, which hinders fabrication reproducibility. Herein, nondestructive surface/interface passivation using 4‐fluoroaniline (FAL) is established. FAL is not only an effective antisolvent candidate for surface modification, but also a large dipole molecule (2.84 Debye) with directional field for charge separation. Density functional theory calculation reveals that the nondestructive properties are attributed to both the conjugated amine in aromatic ring and the para‐fluoro‐substituent. A hot vapor assisted colloidal process is employed for the post‐treatment. The molecular passivation yields an ultrathin protection layer with a hydrophobic fluoro‐substituent tail and thus enhances the stability and optoelectronic properties. FAL post‐treated perovskite solar cell (PSC) delivers a 20.48% power conversion efficiency under ambient conditions. Micro‐photoluminescence reveals that passivation activates the dark defective state at the surface and interface, delivering the impact picture of boundary on the local carriers. This work demonstrates a generic nondestructive chemical approach for improving the performance and stability of PSCs.
Hybrid Architectures of Heterogeneous Carbon Nanotube Composite Microstructures Enable Multiaxial Strain Perception with High Sensitivity and Ultrabroad Sensing Range
Authors: Sun Kahyun , Ko Hangil , Park Hyun‐Ha , Seong Minho , Lee Sang‐Hyeon , Yi Hoon , Park Hyung Wook , Kim Tae‐il , Pang Changhyun , Jeong Hoon Eui
Published: November 2018

Low‐dimensional nanomaterials are widely adopted as active sensing elements for electronic skins. When the nanomaterials are integrated with microscale architectures, the performance of the electronic skin is significantly altered. Here, it is shown that a high‐performance flexible and stretchable electronic skin can be produced by incorporating a piezoresistive carbon nanotube composite into a hierarchical topography of micropillar–wrinkle hybrid architectures that mimic wrinkles and folds in human skin. Owing to the unique hierarchical topography of the hybrid architectures, the hybrid electronic skin exhibits versatile and superior sensing performance, which includes multiaxial force detection (normal, bending, and tensile stresses), remarkable sensitivity (20.9 kPa−1, 17.7 mm−1, and gauge factor of 707 each for normal, bending, and tensile stresses), ultrabroad sensing range (normal stress = 0–270 kPa, bending radius of curvature = 1–6.5 mm, and tensile strain = 0–50%), sensing tunability, fast response time (24 ms), and high durability (>10 000 cycles). Measurements of spatial distributions of diverse mechanical stimuli are also demonstrated with the multipixel electronic skin. The stress–strain behavior of the hybrid structure is investigated by finite element analysis to elucidate the underlying principle of the superior sensing performance of the electronic skin.
Carbon Nanodots as Feedstock for a Uniform Hematite‐Graphene Nanocomposite
Authors: Strauss Volker , Anderson Mackenzie , Wang Chenxiang , Borenstein Arie , Kaner Richard B.
Published: November 2018

High degrees of dispersion are a prerequisite for functional composite materials for applications in electronics such as sensors, charge and data storage, and catalysis. The use of small precursor materials can be a decisive factor in achieving a high degree of dispersion. In this study, carbon nanodots are used to fabricate a homogeneous, finely dispersed Fe2O3‐graphene composite aerogel in a one‐step conversion process from a precursor mixture. The laser‐assisted conversion of small size carbon nanodots enables a uniform distribution of 6.5 nm Fe2O3 nanoparticles during the formation of a highly conductive carbon matrix. Structural and electrochemical characterization shows that the features of both material entities are maintained and successfully integrated. The presence of Fe2O3 nanoparticles has a positive effect on the active surface area of the carbon aerogel and thus on the capacitance of the material. This is demonstrated by testing the performance of the composite in supercapacitors. Faradaic reactions are exploited in an aqueous electrolyte through the high accessible surface of the incorporated small Fe2O3 nanoparticles boosting the specific capacitance of the 3D turbostratic graphene network significantly.
Photocatalysis and Photoelectrocatalysis Methods of Nitrogen Reduction for Sustainable Ammonia Synthesis
Authors: Ithisuphalap Kemakorn , Zhang Hanguang , Guo Lin , Yang Qingui , Yang Haipeng , Wu Gang
Published: November 2018

Ammonia (NH3) is one of the essential chemicals as a fertilizer and as a starting reagent for various chemicals with a production expectation of 200 million tonnes for 2018. With the development of renewable energy technologies such as hydrogen fuel cells, hydrogen also has emerged as an innovative clean energy source. Ammonia is a suitable hydrogen fuel carrier since a molecule of ammonia can carry up to three atoms of hydrogen. Recently, photochemical synthesis via nitrogen reduction has gained considerable attention as a sustainable method for the production of ammonia. The performance of the photoreduction of nitrogen lies in the developments of the photocatalysts and photoelectrocatalysts. Therefore, it is essential to understand the fundamentals of nitrogen reduction processes along with apprehending the challenges that limit the progress of catalysts. In this review, the basic understanding of photoreduction of nitrogen is highlighted, emphasizing on the challenges and effective methods to control defects, structures, and morphologies of materials for the catalyst development. The methods for ammonia detection and uncertainties in calculating the efficiency of the photochemical process are also addressed.
Container‐based cluster orchestration systems: A taxonomy and future directions
Authors: Rodriguez Maria A. , Buyya Rajkumar
Published: November 2018

Containers, enabling lightweight environment and performance isolation, fast and flexible deployment, and fine‐grained resource sharing, have gained popularity in better application management and deployment in addition to hardware virtualization. They are being widely used by organizations to deploy their increasingly diverse workloads derived from modern‐day applications such as web services, big data, and internet of things in either proprietary clusters or private and public cloud data centers. This has led to the emergence of container orchestration platforms, which are designed to manage the deployment of containerized applications in large‐scale clusters. These systems are capable of running hundreds of thousands of jobs across thousands of machines. To do so efficiently, they must address several important challenges including scalability, fault tolerance and availability, efficient resource utilization, and request throughput maximization among others. This paper studies these management systems and proposes a taxonomy that identifies different mechanisms that can be used to meet the aforementioned challenges. The proposed classification is then applied to various state‐of‐the‐art systems leading to the identification of open research challenges and gaps in the literature intended as future directions for researchers.
Caspary's fungi from Baltic amber: historic specimens and new evidence
Authors: Kettunen Elina , Sadowski Eva‐Maria , Seyfullah Leyla J. , Dörfelt Heinrich , Rikkinen Jouko , Schmidt Alexander R.
Published: November 2018

Amber is a valuable source of Mesozoic and Cenozoic fossil fungi. The earliest amber‐preserved fungi were described in the nineteenth and early twentieth centuries from Eocene Baltic amber. In 1907, Richard Klebs summarized the legacy of Robert Caspary based on his specimens, research notes and publications. This treatise contains descriptions and illustrations of 13 morphologies of fossil fungi which have not been investigated since. We managed to locate six of Caspary's amber specimens and imaged and re‐investigated the fossil fungi within. We provide amended descriptions of these six specimens, select new specimens from historic and recent collections which are probably conspecific with five fossils that appear to have been lost, and finally also describe and evaluate five newly found fossil fungi from Baltic amber. The fungi belong to the phylum Ascomycota (Subkingdom Dikarya). Only two of Caspary's fungi can be confidently assigned to modern genera,Metacapnodium(Metacapnodiaceae) andCalicium(Caliciaceae). The new combinationCalicium succini(Caspary) Rikkinen & A. R. Schmidt is made. The fossils originally placed inAcremonium,Cetraria,Gonatobotrys,Ramularia,StilbumandTorulacannot be assigned to these genera, and should not be used as minimum age constrains for the respective lineages.
Phase‐Specific Precipitation of Intermetallic Phases in Fe Al Mn Ni C Duplex Steels
Authors: Drouven Carsten , Song Wenwen , Bleck Wolfgang
Published: November 2018

A Fe–Al–Mn–Ni–C steel is designed explicitly to precipitate intermetallic phases in specific phases of a duplex steel. CALPHAD‐assisted alloy design is carried out with respect to an innovative “solublility‐assisted precipitation” (SAP) mechanism. A four phase equilibrium comprising of ferrite, austenite, κ‐phase (Fe3AlC), and B2‐phase (NiAl) is stabilized in a suitable annealing window. The processing conditions are adjusted according to elemental partitioning and consequential stabilization of κ‐phase in austenite and B2‐phase in ferrite. The feasibility of the SAP mechanism is validated by investigation of microstructure and precipitation evolution using electron microscopy and site‐specific atom probe tomography.
Tragfähigkeit von Kehlnahtverbindungen normal‐ und höherfester Stähle
Authors: Kuhlmann Ulrike , Spiegler Jennifer
Published: November 2018

Die Anforderung immer schlankerer und filigraner Konstruktionen mit hohen Beanspruchungen führen konsequenterweise zum Einsatz von höherfesten Stählen. Maßgebend für den Einsatz höherfester Stähle sind neben Fragen der Stabilität und für Brücken u. ä. Ermüdung in erster Linie die Anschluss‐ und Verbindungsmöglichkeiten. Im Zuge vorheriger Forschungsvorhaben konnte bereits ein an höherfeste Stähle angepasstes Bemessungsmodell nach Rasche für Kehlnähte gleicher Grundwerkstoffe entwickelt werden. Offen war dabei das Vorgehen für Mischverbindungen, wenn also höherfeste Stähle wie S690 an normalfeste Stähle (z. B. S355) angeschlossen werden. Ziel des Forschungsvorhabens war daher, die Anwendbarkeit des bereits angepassten Bemessungsmodells für Kehlnähte aus normal‐ und höherfesten Baustählen zu überprüfen und ggf. zu erweitern. Dies soll zur Verbesserung der normativen Tragfähigkeit von Kehlnahtverbindungen bei Mischverbindungen in den Stahlbaunormen herangezogen werden und als Normenvorschlag in die Weiterentwicklung der europäischen Norm eingehen.
Aufgeschweißte Flach‐ und Vierkantschienen von Kranbahnträgern
Authors: Euler Mathias , Kuhlmann Ulrike
Published: November 2018

Die Radlasten von Brückenlaufkranen werden über Kranschienen in die unterstützenden Kranbahnträger eingeleitet. Für viele Anwendungen ist es ausreichend, Flach‐ oder Vierkantstäbe als Kranschienen zu verwenden und auf den Kranbahnträgern mit in Trägerlängsrichtung durchgehenden Doppelkehlnähten zu befestigen. Mit der Einführung der europäischen Stahlbaunormen (Eurocode 3) im Jahr 2010 hat sich die ansetzbare Ermüdungsfestigkeit der Konstruktionsdetails mit Radlasteinleitung, zu denen die Schienenschweißnähte zählen, erheblich reduziert. Es wird ein Bemessungsvorschlag vorgestellt, der sich erstmals auf realitätsnahe Ermüdungsversuche an Schienenschweißnähten abstützen kann und eine wirtschaftlichere Dimensionierung hinsichtlich Ermüdung gestattet.
Neue Lösungen zur energetischen Ertüchtigung von Gebäudehüllen in Stahlleichtbauweise
Authors: Kuhnhenne Markus , Brieden Matthias , Ungermann Dieter , Wiegand Alexander
Published: November 2018

Der vorliegende Beitrag thematisiert ausgewählte Ergebnisse, die innerhalb des FOSTA‐Forschungsprojekts „Bauen im Bestand – Lösungen für Dach und Fassade in Stahlleichtbauweise” erarbeiten worden sind. Das Projekt hat Möglichkeiten untersucht, bestehende Dach‐ und Fassadensysteme in Stahlleicht‐ und massiver Bauweise mit Bausystemen des Stahlleichtbaus energetisch zu ertüchtigen. Als Ertüchtigungsmaßnahmen wurden dabei Stahl‐Sandwichelemente und modulare Stahlleichtbaukonstruktionen, die beispielsweise aus Stahltragprofilen, Wärmedämmung und Stahlfeinblechprofilen bestehen, berücksichtigt. Neben hygrothermisch‐bauphysikalischen Untersuchungen wurden auch statisch‐mechanische Bewertungen der energetisch optimierten Bausysteme durchgeführt.

Innerhalb des Beitrags werden Erkenntnisse erläutert und diskutiert, die als Ergänzung zu den bereits in [1] veröffentlichten zu verstehen sind und die die Bandbreite des Forschungsprojekts repräsentieren. Neben numerischen und experimentellen Untersuchungsergebnissen aus dem Bereich Bauphysik werden auch Fragestellungen vorgestellt und Lösungen aufgezeigt, die das Tragverhalten und die baukonstruktive Ausbildung sowohl der Ertüchtigungs‐ als auch der ertüchtigten Bauteile betreffen. Abschließend werden die auf Ebene der Einzelbauteile erzielten Ergebnisse im Kontext des Gesamtgebäudes beleuchtet und auf diesem Niveau hinsichtlich ihrer Effektivität bewertet.