bluuebunny/crossref_metadata_2025_split huggingface dataset:
Thermal stability of poly[1‐(trimethylsilyl)‐1‐propyne] and the gas chromatographic stationary phase based on it
Authors: Shiryaeva Valeriya , Popova Tamara , Korolev Alexander , Kanateva Anastasiia , Kurganov Alexander 
Published: July 2018

AbstractThe thermal stability of poly[1‐(trimethylsilyl)‐1‐propyne] is investigated by heating the capillary column with this polymer as the stationary phase with the subsequent separation of the test mixture of light hydrocarbons. It is shown that heating of the column up to 130°C does not cause a decrease in efficiency or in the retention time of solutes. A further increase in temperature results in both decrease in column efficiency and sorbate retention. However, a decrease in column retentivity goes in one way for all the tested hydrocarbons. At the same time, the efficiency of the column is changed to a lesser degree for methane and ethane up to the temperature of polymer degradation, while for propane, butane, and iso‐butane the difference is rather sharp. The most expressed decrease in efficiency was found for iso‐butane: the column efficiency for this sorbate versus temperature of heating had two stages. The diffusion coefficients for sorbates in the polymeric phase were also evaluated and the sharp decrease in their values was found after the column heating.
Magnetic chitosan functionalized with β‐cyclodextrin as ultrasound‐assisted extraction adsorbents for the removal of methyl orange in wastewater coupled with high‐performance liquid chromatography
Authors: Dai Yunliang , Row Kyung Ho 
Published: July 2018

AbstractThree types of choline chloride based deep eutectic solvents were prepared and used to modify magnetic chitosan. The adsorption capacity of the three deep‐eutectic‐solvent‐modified magnetic chitosan/carboxymethyl‐β‐cyclodextrin for removing methyl orange from wastewater was examined. The different deep eutectic solvents were used to strengthen the adsorption capacity of magnetic chitosan. Deep‐eutectic‐solvent‐modified magnetic chitosan/carboxymethyl‐β‐cyclodextrin materials were characterized by Fourier transform infrared spectroscopy and Brunauer–Emmett–Teller surface area measurements. Among the three deep eutectic solvents, choline chloride/glycerol (1:2) modified magnetic chitosan/carboxymethyl‐β‐cyclodextrin showed the highest adsorption capacity to methyl orange. Therefore, choline chloride/glycerol (1:3, 1:4, 1:5, 1:6) deep eutectic solvents were prepared for the assay, and choline chloride/glycerol‐modified magnetic chitosan/carboxymethyl‐β‐cyclodextrin prepared with choline chloride/glycerol (1:3) (volume: 40 μg, contact time: 30 min, and pH: 6) had the best adsorption capacity over the concentration range of 10–200 μg/mL.
Chromatographic characterization of amphiphilic di‐ and tri‐block copolymers of poly(ethylene oxide) and poly(ε‐caprolactone)
Authors: Irfan Muhammad , Bhayo Adnan Murad , Musharraf Syed Ghulam , Malik Muhammad Imran 
Published: July 2018

AbstractAmphiphilic di‐ and tri‐block copolymers based on poly(ethylene oxide) as a hydrophilic segment and poly(ε‐caprolactone) as a hydrophobic part are synthesized by the ring‐opening polymerization of ε‐caprolactone while using poly(ethylene glycol)s and methoxy poly(ethylene glycol)s of varying molar masses as macro‐initiators. The synthesized block copolymers are characterized with respect to their total relative molar mass and its distribution by size exclusion chromatography. Liquid chromatography at critical conditions of both blocks is established for the analysis of individual block lengths and tracking presence of unwanted homopolymers of both types in the block copolymer samples. New critical conditions of polycaprolactone on reversed phase column are reported using organic mobile phase. The established critical conditions of polycaprolactone extended the applicable molar mass range significantly compared to already reported critical conditions of polycaprolactone in aqueous mobile phase. Block copolymers are also analyzed at critical conditions of poly(ethylene glycol). Complete analysis of the di‐ and tri‐block copolymers at corresponding critical conditions provided a fair estimate of molar mass of non‐critical block besides information regarding presence of homopolymers of both types in the samples.
Assessment of periglacial response to increased runoff: An Arctic hydrosystem bears witness
Authors: Bernard Eric , Friedt Jean Michel , Schiavone Sophie , Tolle Florian , Griselin Madeleine 
Published: July 2018

AbstractIn the general context of global warming, the cryosphere appears as an environment that exhibits a strong sensitivity to climate variations. Overall, glacier systems are now known to be reliable indicators of climate trends. Although glacier dynamics are subject to international monitoring networks, periglacial environments are much less observed. However, these newly deglaciated areas get wider since glaciers are retreating, and their dynamics become increasingly significant. The observed increase in water fluxes, temperature and precipitation, permafrost melting, and reduced cold periods induce a combined control on modifications of the glacier and periglacial dynamics. Such consequences are also visible on the landscape, hinting at an adaptation of the environment to the climatic forcing.The work carried out focuses on Austre Lovénbreen area, a small 10‐km2 glacier basin (Svalbard, 78.87°N, 12.15°E, west coast of Spitsbergen) exhibiting typical arctic glacial retreat trends. Its geomorphological characteristics as well as its observatory status make it an appropriate control area. Our investigations are based on a combination of classical on‐site snow, ice, and geomorphological measurements, combined with innovative methods using aerial photography (e.g., from unmanned aerial systems) and digital photogrammetric image processing. Such data currently complement classical remote sensing methods (satellite imagery), providing both improved resolution and high temporal repeatability. Indeed, short acquisition time and flexibility allows measurements within very short time intervals, a requirement when short events are significant in the whole system evolution: The speed at which climatic change‐related events occur requires such fine‐grained spatial and temporal monitoring.This work highlights an increase of sediment transfers during the last decade that ties in with the increasing liquid precipitation as well as a trend of rising temperatures. The newly deglaciated area, particularly at the glacier front, is in constant and fast reshaping, which is quantifiable from 1 year to another, assessing the increase of periglacial landscape modification. This small‐scale detailed analysis enlightens on global processes occurring in Arctic regions demonstrating ongoing geomorphological and landscape changes as a consequence of glacier retreat and newly exposed periglacial environments.
Quantitative interactions between total and specific enzyme activities and C and N contents in earthworm‐affected pear orchard soil
Authors: Brzezińska Małgorzata , Lipiec Jerzy , Frąc Magdalena , Oszust Karolina , Szarlip Paweł , Turski Marcin 
Published: July 2018

AbstractThe current study describes quantitatively the interactions between (a) activity of extracellular enzymes: β‐glucosidase (BG), protease (Prot), alkaline phosphatase (Alk P), and acid phosphatase (Acid P); (b) intracellular activities: respiration, dehydrogenase activity (DHA); and (c) C and N contents of soil: Corg—organic carbon, Cmic—microbial biomass, ratio Cmic:Corg, Ntot—total nitrogen, and ratio C:N in earthworm‐affected and surrounding loess soil under a pear orchard. The soil tested was collected from: burrow walls (0–3 mm) and a transition zone (3–7 mm) both forming drilosphere, bulk soil (20 mm from the burrow wall), and cast aggregates. The enzyme activities were presented as total ‘tot’ (per gram of dry soil mass) and specific ‘spec’ (per Cmic). It was shown that soil Cmic, basal respiration, BGtot, Prottot, and Alk Ptot were significantly positively correlated with Corg, Cmic:Corg, Ntot, and C:N (r = 0.627–0.976). However, the specific BGspec, Protspec, and Acid Pspec were negatively correlated, while specific respiration (qCO2) and Alk Pspec were not correlated with most soil characteristics. The relationships between DHAtot, DHAspec, and all soil characteristics were positive and had the highest correlation coefficients (r = 0.703–0.989). Response ratio of the enzyme activity was more strongly affected by enzyme activity location (extracellular vs. intracellular) and presentation method (total vs. specific), than by earthworm‐affected soil compartments. The results suggest a need to consider the method of enzyme activity presentation (specific vs. total) that supports understanding ecologically relevant microbial processes in earthworm‐inhabited orchard soils.
Accelerated MR parameter mapping with a union of local subspaces constraint
Authors: Mandava Sagar , Keerthivasan Mahesh B. , Li Zhitao , Martin Diego R. , Altbach Maria I. , Bilgin Ali 
Published: July 2018

PurposeA new reconstruction method for multi‐contrast imaging and parameter mapping based on a union of local subspaces constraint is presented.TheorySubspace constrained reconstructions use a predetermined subspace to explicitly constrain the relaxation signals. The choice of subspace size

impacts the approximation error vs noise‐amplification tradeoff associated with these methods. A different approach is used in the model consistency constraint (MOCCO) framework to leverage the subspace model to enforce a softer penalty. Our proposed method, MOCCO‐LS, augments the MOCCO model with a union of local subspaces (LS) approach. The union of local subspaces model is coupled with spatial support constraints and incorporated into the MOCCO framework to regularize the contrast signals in the scene.MethodsThe performance of the MOCCO‐LS method was evaluated in vivo on T1 and T2 mapping of the human brain and with Monte‐Carlo simulations and compared against MOCCO and the explicit subspace constrained models.ResultsThe results demonstrate a clear improvement in the multi‐contrast images and parameter maps. We sweep across the model order space

to compare the different reconstructions and demonstrate that the reconstructions have different preferential operating points. Experiments on T2 mapping show that the proposed method yields substantial improvements in performance even when operating at very high acceleration rates.ConclusionsThe use of a union of local subspace constraints coupled with a sparsity promoting penalty leads to improved reconstruction quality of multi‐contrast images and parameter maps.
Multi‐parametric T2* magnetic resonance fingerprinting using variable echo times
Authors: Wyatt Cory R. , Smith Travis B. , Sammi Manoj K. , Rooney William D. , Guimaraes Alexander R. 
Published: July 2018

The use of quantitative imaging biomarkers in the imaging of various disease states, including cancer and neurodegenerative disease, has increased in recent years. T1, T2, and T2* relaxation time constants have been shown to be affected by tissue structure or contrast infusion. Acquiring these biomarkers simultaneously in a multi‐parametric acquisition could provide more robust detection of tissue changes in various disease states including neurodegeneration and cancer. Traditional magnetic resonance fingerprinting (MRF) has been shown to provide quick, quantitative mapping of T1 and T2 relaxation time constants. In this study, T2* relaxation is added to the MRF framework using variable echo times (TE).To demonstrate the feasibility of the method and compare incremental and golden angle spiral rotations, simulated phantom data was fit using the proposed method. Additionally, T1/T2/T2*/δf MRF as well as conventional T1, T2, and T2* acquisitions were acquired in agar phantoms and the brains of three healthy volunteers.Golden angle spiral rotation was found to reduce inaccuracy resulting from off resonance effects. Strong correlations were found between conventional and MRF values in the T1, T2, and T2* relaxation time constants of the agar phantoms and healthy volunteers.In this study, T2* relaxation has been incorporated into the MRF framework by using variable echo times, while still fitting for T1 and T2 relaxation time constants. In addition to fitting these relaxation time constants, a novel method for fitting and correcting off resonance effects has been developed.
Synthesis of a novel hyperbranched and phosphorus‐containing charring‐foaming agent and its application in polypropylene
Authors: Zhu Changjiang , He Mingshan , Cui Jianguang , Tai Qilong , Song Lei , Hu Yuan 
Published: July 2018

In this work, a novel hyperbranched and phosphorus‐containing triazine derivative (HPCFA) is synthesized. HPCFA is used as charring‐foaming agent and combined with ammonium polyphosphate (APP) as intumescent flame retardant to flame retard polypropylene (PP). PP/HPCFA/APP composite can achieve limited oxygen index value of 31% and pass UL 94V‐0 rating by addition of 20 wt% HPCFA/APP (1/2, w/w). Besides, HPCFA is compared with another hyperbranched charring‐foaming agent (HCFA). HPCFA and HCFA have similar chemical structure, and their only difference is that HPCFA has phosphorus‐containing unit in the main chain compared with HCFA. HPCFA/APP system exhibits superior flame retardancy compared with HCFA/APP system. Char residue analysis demonstrates that HPCFA/APP system can form denser and more compact char layer in comparison with that of HCFA/APP system.
Exendin‐4 enhances radiation response of prostate cancer
Authors: He Wenjing , Li Junhe 
Published: July 2018

BackgroundExendin‐4, one of the most widely used antidiabetic drugs, has recently been reported to have potential antitumor effects in cancers. Prostate cancer (PC) is one of the most common cancers in male patients with type 2 diabetes mellitus, and radiotherapy plays a vital role in the therapy of PC. Whether exendin‐4 has the potential to enhance PC response to ionizing radiation (IR) remains unknown. We aimed to explore whether exendin‐4 radiosensitizes PC cells.MethodsGLP‐1 receptor (GLP‐1R) expression in PC tissue samples and cell lines were analyzed, Human prostate cancer cells (PC3 and LNCap) were treated with IR and exendin‐4, and subjected to proliferation, clone formation, cell cycle, immunoblotting, and immunohistochemical analysis. An in situ prostate tumor of animal model was established.ResultsWe found that GLP‐1R was expressed in human PC tissues and cell lines. 1‐100 nM exendin‐4 promoted the anti‐proliferation effects of IR in vitro and in vivo, and enhanced radiation‐induced G2/M cycle arrest in PC cells in a dose‐dependent manner. Furthermore, Ex‐4 increased AMPK phosphorylation, decrease the levels of p‐mTOR, cyclin B, and p34cdc2.ConclusionsOur study suggested exendin‐4 radiosensitizes PC cells via activation of AMPK A and subsequent inhibition of p‐mTOR, cyclin B, and p34cdc2 activation.
Quantification of hydrolyzed peptides and proteins by amino acid fluorescence
Authors: Allenspach Martina D. , Fuchs Jens A. , Doriot Nicolas , Hiss Jan A. , Schneider Gisbert , Steuer Christian 
Published: July 2018

Reliable quantification of peptides and proteins is essential for drug discovery. We report the successful development and validation of an accurate and broadly applicable high performance liquid chromatography hyphenated to fluorescence detector procedure for the quantitative determination of the aromatic amino acids tyrosine, phenylalanine, and tryptophan, without relying on derivatization chemistry. Using ion‐pair chromatography, fluorescent amino acids were clearly separated within 10 minutes. The hydrolysis of peptides was performed under acidic and heated conditions to yield the monomeric building blocks. Various protecting agents were tested to ensure tryptophan stability. The presented analytical method accurately (>95%) quantifies all fluorescent residues. The power of the method was confirmed by correct quantification of protein reference standard to 98.6% over all fluorescence traces. The method allowed us to identify pre‐analytical differences between the nominal and actual concentrations of 12 peptide solutions. Salt formation, weighing errors, and other pre‐analytical pitfalls resulted in noteworthy differences of up to 85% between the indicated and actual concentration of peptide solutions, subsequently leading to false positive or negative interpretation of activity data. Finally, only one solution is needed to perform quantification as well as UV‐purity tests and can further be used as stock solution for activity testing.
Receiver station in Budapest for Q/V band satellite site diversity and adaptive coding and modulation experiments with Alphasat
Authors: Csurgai‐Horváth László 
Published: July 2018

SummaryThe European Space Agency in cooperation with Inmarsat launched the Alphasat communication satellite in 2013, which hosts four technology demonstration payloads. One of them is the Aldo Paraboni payload composed of the Q/V band communication and Ka/Q band propagation experiments. The payload and the communication experiment are funded by the Italian Space Agency. Budapest University of Technology, Hungary in cooperation with Joanneum Research, Austria built a receiver station to conduct site diversity and adaptive coding and modulation experiments over the Q/V band satellite channel. The transmitter/receiver station in Austria and the receiver station in Hungary form a long‐distance diversity system that is used to investigate the capabilities of the adaptive technique under various propagation conditions controlled by the local signal quality at the receiver site in Budapest. This paper provides a detailed overview of the diversity station in Budapest. The operation of the adaptive coding and modulation experiment is illustrated with measurements performed in 2017.
Graphene Oxide: An Efficient Carbocatalyst for the Facile Synthesis of Isoindolo[2, 1‐a]quinazoline‐5,11‐diones via Domino Condensation under Solvent‐Free Conditions
Authors: Bodhak Chandan , Hazra Subhenjit , Pramanik Animesh 
Published: July 2018

AbstractAn efficient and environmentally benign synthetic method has been developed for the library synthesis of biologically important multi‐functionalized isoindolo[2, 1‐a]quinazolines by two component domino condensation of 2‐carboxybenzaldehyde and 2‐aminobenzohydrazides/2‐aminobenzamides using graphene oxide (GO) as catalyst under solvent free conditions. The solvent‐free strategy exploiting inexpensive and eco‐compatible GO as mild carbocatalyst with large surface area is the major significant advantage of the present protocol. Furthermore, low catalyst loading, good to excellent yield of the products and easy recovery and recyclability of GO attribute considerable supremacy to the present protocol.
Introduction
Authors: Pohjolainen Seppo , Myllykoski Tuomas , Mercat Christian , Sosnovsky Sergey 
Published: July 2018

AbstractThis chapter presents motivation, goals, and organisational details of two EU projects: MathGeAr and MetaMath, funded by the EU Tempus programme. The goal was to study and improve mathematics education for STEM specialisations in Russian (MetaMath) and Georgian/Armenian (MathGeAr) universities. The analysis carried out in the beginning of the two projects and described in this book has been followed up by modernisation and piloting phases. Special attention has been paid to the introduction of modern educational technologies, such as the intelligent multifunctional platform Math-Bridge used as an online component of modernised mathematical courses.The first section discusses the importance of mathematics as a part of the engineering sciences and education and global challenges caused by lack of student motivation and relatively high drop-out rates. New learning approaches are needed to increase students’ motivation. These approaches can be supported by using information and communication technology.The second section introduces the two parallel projects MetaMath and MathGeAr, with their goals and organisational details, and their participants from the EU, Russia, Georgia, and Armenia. An essential part of the project is modernisation of selected courses with a special focus on technology-enhanced learning.Students’ perceptions of mathematics have impact on their motivation and performance. In a broader sense they contain cultural differences between nations and institutions. The third section studies engineering mathematics students’ perceptions at all the universities participating in the project by analysing an online survey carried out among the students.
Methodology for Comparative Analysis of Courses
Authors: Sosnovsky Sergey 
Published: July 2018

AbstractThis chapter outlines the methodology for the comparative analysis of mathematics courses taught in participating Russian, Georgian, Armenian and EU universities to the students of technical and engineering programmes. It identifies a range of factors, based on which the courses have been compared, and it provides recommendations on performing the comparison. The most important part of the comparison is finding the correspondence between the actual content taught in counterpart courses of the two target universities. In order to perform this comparison in a meaningful way, the we needed a certain instrument, enabling consistent characterisation of the content of the compared courses in terms of the mathematical knowledge involved. We adopted the SEFI Framework for Mathematics Curricula in Engineering Education (SEFI, 2013) for these purposes.
Overview of Engineering Mathematics Education for STEM in Russia
Authors: Pokholkov Yury , Zaitseva Kseniya , Kuprianov Mikhail , Baskakov Iurii , Pozdniakov Sergei , Ivanov Sergey , Chukhnov Anton , Kolpakov Andrey , Posov Ilya , Rybin Sergey , Akimushkin Vasiliy , Syromiasov Aleksei , Soldatenko Ilia , Zakharova Irina , Yazenin Alexander 
Published: July 2018

AbstractHigher education in general and engineering education in particular are divided into three levels in Russia. The first level is the Bachelor’s degree course; the second level is the specialist and Master’s degree program; the third level is the postgraduate training program.
Overview of Engineering Mathematics Education for STEM in EU
Authors: Pohjolainen Seppo , Myllykoski Tuomas , Mercat Christian , Sosnovsky Sergey 
Published: July 2018

AbstractThis chapter introduces engineering mathematics education in the EU, especially in the participating countries Finland and France. Their educational systems correspond to each other to some extent, but still differ in many aspects. Special emphasis is on the curricula of Tampere University of Technology and University of Lyon. The engineering curricula of these universities contains comparable amount of engineering mathematics depending on the engineering study program. Normally the courses are taught in the beginning of studies. As mathematics is a universal language, the contents of the courses are well comparable.
Case Studies of Math Education for STEM in Armenia
Authors: Pohjolainen Seppo , Myllykoski Tuomas , Mercat Christian , Sosnovsky Sergey 
Published: July 2018

AbstractArmenian State Pedagogical University (ASPU) was established on November 7, 1922 and in 1948 it was named after the great Armenian Enlightener Educator Khachatur Abovian. ASPU implements a three-level education system (Bachelor, Master and Doctorate studies). It has ten faculties.