bluuebunny/crossref_metadata_2025_split huggingface dataset:
On the functionalization and characterization of hydroxyl‐terminated polybutadiene with octyl‐1‐azide and the evaluation of polyurethane elastomers based on such modified HTPB
Authors: Lemos Mauricio Ferrapontoff , Mendes Luis Claudio , Bohn Manfred A. 
Published: October 2020

AbstractHydroxyl‐terminated polybutadiene (HTPB) has been modified with azido‐containing substances to be applied in propulsion systems. Pristine HTPB has compatibility issues with energetic polar substances and plasticizers, which is a drawback to develop new high‐energy propellants. This work presents a path for the functionalization of HTPB, carried out through a controlled bulk reaction of it with octyl‐1‐azide. Then it was reacted with isophorone diisocyanate with or without dioctyl adipate (DOA). Structural, thermal, rheological, and dynamic‐mechanical assessments were accomplished. Infrared revealed the arising of absorption bands associated to the CN stretching. From 13C and 1H nuclear magnetic resonances, it is possible to deduce the presence of amine, aziridine, and imine chemical groups, which may promote compatibilization with other polar and energetic substances. The chemical modification induced an increase of viscosity. With respect to the glass–liquid and glass–rubber transitions, the modification shifted them slightly to higher temperatures, but created stiffer networks, in agreement with the increase of polarity and chain interaction due to the presence of N‐containing functionalities. Regarding the solid elastomer binder, the storage shear modulus and molecular mobility were influenced by the type of HTPB and DOA content. In general, the modified HTPB has physical properties like pristine HTPB.
Chemical and morphological effects of blended sulfonated poly(styrene‐isobutylene‐styrene) and isopentylamine for direct methanol fuel cell applications
Authors: Barrios‐Tarazona Karen , Suleiman David 
Published: October 2020

AbstractIn this study, blend membranes based on a combination of sulfonated poly (styrene‐isobutylene‐styrene) (SIBS) with isopentylamine (IPA) were synthetized as potential candidates for direct methanol fuel cell (DMFC) applications. The impact of sulfonation level (57–93 mol%) and percentage of IPA incorporation (1, 3, and 5 wt%) were analyzed via different properties of the resulting membrane. FTIR analysis showed that IPA was successfully incorporated into the sulfonated polymer matrix and also confirmed the interaction between the sulfonic and amine groups. This interaction generates significant morphological changes in the nanostructure of the membranes that are evident through results of small angle x‐ray scattering and atomic force microscopy analysis. Proton conductivity and methanol permeability of the membranes were also analyzed. Proton conductivity was significantly enhanced with the incorporation of IPA at an optimum loading, creating additional paths for the conduction of protons through the membrane. It was also sensitive to the morphological changes produced after the IPA incorporation and the interconnection between the ionic domains. Methanol permeability increased slightly due to the additional water domains and the inability of the isopentyl groups of IPA to block the free‐volume in the membrane. Despite this, the selectivity (proton conductivity over methanol permeability) of the membranes was comparable to the state‐of‐the‐art Nafion®, especially at an optimum IPA incorporation of 3 wt%.
Molecularly imprinted macroporous polymer monolithic layers for L‐phenylalanine recognition in complex biological fluids
Authors: Antipchik Mariia , Dzhuzha Apollinariia , Sirotov Vasilii , Tennikova Tatiana , Korzhikova‐Vlakh Evgenia 
Published: October 2020

ABSTRACTIn present work, the development of macroporous monolithic layers bearing the artificial recognition sites toward L‐phenylalanine has been carried out. The set of macroporous poly(2‐aminoethyl methacrylate‐co‐2‐hydroxyethyl methacrylate‐co‐ethylene glycol dimethacrylate) materials with average pore size ranged in 340–1200 nm was synthesized. The applicability of Hildebrand's and Hansen's theories for the prediction of polymer compatibility with porogenic solvents was evaluated. The dependences of average pore size on theoretically calculated parameters were plotted. The linear trend detected for Hansen's theory has indicated the high suitability of this approach to select appropriate porogens. The synthesized monolithic MIP layers were tested toward the ability to rebind phenylalanine‐derivative in microarray format. The influence of such factors as average pore size of the material, the concentration of template molecule in polymerization mixture, interaction time of analyte with its imprinted sites on binding efficiency were studied. The developed materials demonstrated good analyte rebinding from buffer solution with recognition factors 2.5–3.4 depending on the MIP sample. The comparable rebinding efficiency was also detected when the analysis was carried using complex biological media. The selectivity of phenylalanine binding from the equimolar mixture of structural analogues was 81.9% for free amino acid and 91.2% for labeled one.
Synergistic enhancement of mechanical, viscoelastic, transport, thermal, and radiation aging characteristics through chemically bonded interface in nanosilica reinforced EPDM‐CIIR blends
Authors: Ashok Neelesh , Prakash Karthikeyan , Selvakumar Deepika , Balachandran Meera 
Published: October 2020

AbstractThe study investigates the influence of bis(3‐triethoxysilylpropyl)tetrasulfide (TESPT) grafted nanosilica (NS) reinforcement on the mechanical, viscoelastic, thermal, and transport characteristics as well as behavior after exposure to different cumulative γ‐radiation doses of EPDM‐CIIR blends for application in nuclear and hydrocarbon environments. The tensile strength and modulus of the nanocomposites were enhanced upto 64% and 118%, respectively whereas solvent diffusion coefficient reduced by 22%. The degradation onset temperature improved from 485°C for unfilled blends to 503°C for the nanocomposites. γ‐radiation aging resistance of EPDM‐CIIR blends improved with incorporation of nanosilica, with blends containing 7.5phrNS showing optimum properties and radiation aging resistance. The property improvements are attributed to the dispersion of NS and chemically interfaced covalent linkages between SiO2‐EPDM/CIIR chains that provides large interfacial area for effective stress transfer and creates barrier to free radical and solvent permeation. The applicability of Korsmeyer‐Peppas, Peppas‐Sahlin, and Higuchi models to predict of sorption behavior are investigated. Coats‐Redfern and Horowitz‐Metzger models were employed to evaluate the activation energy for thermal degradation. Slight decline in properties at higher nanofiller contents was due to the formation of agglomerates. TEM, FTIR, and rheological curves were utilized to corroborate these observations. FTIR and ESR analysis provided insight on the chemical changes in the nanocomposites after irradiation.
Supramolecular thermoplastic elastomers via self‐complementary quadruple hydrogen bonding between polybutadiene‐based triblock copolymers
Authors: Dai Lu , Jie Suyun , Bu Zhiyang , Li Bo‐Geng 
Published: October 2020

AbstractTwo series of triblock copolymers, polycaprolactone‐b‐polybutadiene‐b‐polycaprolactone (PCL‐b‐PB‐b‐PCL, CBC) and polylactide‐b‐polybutadiene‐b‐polylactide (PLA‐b‐PB‐b‐PLA, LBL), have been synthesized through the ring‐opening polymerization (ROP) of ε‐caprolactone (ε‐CL)/D,L‐lactide (D,L‐LA) catalyzed by Sn(Oct)2 with hydroxyl‐terminated polybutadiene (HTPB) as a macroinitiator. Then, these triblock copolymers are end‐functionalized with 2‐ureido‐4[1H]‐pyrimidinone (UPy) groups to obtain the supramolecular multiblock copolymers UCBC and ULBL as supramolecular thermoplastic elastomers (TPEs). The thermal properties of UCBC and ULBL samples are measured by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and dynamic mechanical analysis (DMA). The tensile tests of all the samples prepared are carried out to investigate the influence of the content of hard segments and the microstructure of PB soft segments on the mechanical properties of supramolecular TPEs.
Effectiveness of the preparation of maleic anhydride grafted poly (lactic acid) by reactive processing for poly (lactic acid)/carbon nanotubes nanocomposites
Authors: Verginio Gleice Ellen Almeida , Montanheiro Thais Larissa do Amaral , Montagna Larissa Stieven , Marini Juliano , Passador Fabio Roberto 
Published: October 2020

AbstractAn effective strategy to increase the properties of poly (lactic acid) (PLA) is the addition of carbon nanotubes (CNT). In this work, aiming to improve the surface adhesion of PLA and CNT a new compatibilizer agent was prepared by reactive processing, PLA grafted maleic anhydride (PLA‐g‐MA) using benzoyl peroxide and maleic anhydride. The effectiveness of the PLA‐g‐MA as a compatibilizer agent was verified for PLA/PLA‐g‐MA/CNT nanocomposites. PLA and PLA‐g‐MA samples were characterized by Fourier transform infrared spectroscopy (FT‐IR) to confirm the grafting reaction of maleic anhydride on PLA chains and by rheological analysis to prove the changes in the matrix PLA after the graphitization reaction. Thermal (differential scanning calorimetry and thermogravimetric analysis), mechanical tests (Izod impact strength and tensile test), and morphological characterization were used to verify the effect of the compatibilizer agent. The preparation of PLA‐g‐MA by reactive extrusion processing proved satisfactory and the nanocomposites presented good thermal and mechanical properties. The addition of the PLA‐g‐MA also contributed to the greater distribution of CNT and can be used as an alternative for the production of PLA/CNT nanocomposites.
Polyethylene glycol modified epoxy acrylateUVcurable3Dprinting materials
Authors: Wang Yiyang , Li Cheng , Tuo Xiaohang , Gong Yumei , Guo Jing 
Published: October 2020

AbstractThe purpose of this paper is to research improvement in the flexibility of epoxy acrylate 3D printing materials so as to satisfy the requirements of clothing attachments or accessories. Tensile tests, differential scanning calorimeter, XRD, rheological and Fourier transform infrared analysis were used to measure and compare the performance and characteristics of polyethylene glycol modified bisphenol‐A epoxy acrylate 3D printed samples with different molecular weights and contents. Based on a comprehensive analysis of the experimental results, the E/PEG1000(1/0.2)‐AA sample was revealed to have an optimal composition ratio. After secondary curing, the tensile strength of the sample rose to 8 MPa, with the elongation being converged to 30%. This paper provides a reference for the modification and improvement of flexible UV‐cured 3D printed products.
Developmental and reproductive safety evaluation of AV7909 anthrax vaccine candidate in rats
Authors: Mylchreest Eve , Smiley M. Autumn , Ballin Jeff D. , Blauth Bruna , Shearer Jeffry , Reece Joshua , Ionin Boris , Savransky Vladimir 
Published: October 2020

AbstractThe AV7909 vaccine, consists of the Anthrax Vaccine Adsorbed (AVA) bulk drug substance and the immunostimulatory Toll‐like receptor 9 agonist oligodeoxynucleotide adjuvant CPG 7909. The purpose of this research was to evaluate the potential maternal, reproductive, and developmental toxicity of AV7909 in rats to support licensure for use in women of childbearing potential. Groups of first generation (F0) female Sprague Dawley rats were dosed by intramuscular injection with water for injection, adjuvant or AV7909 at a volume of 0.5 ml/dose. Each rat received three vaccinations: 14 days prior to start of the mating period, on the first day of the mating period and on gestation day (GD) 7. There was no maternal mortality. Body weights, weight gain, and food consumption were comparable between groups. Findings in F0 females were limited to transient injection site edema and nodules consistent with immunostimulatory effects of the vaccine and adjuvant. Administration of AV7909 did not affect mating, fertility, pregnancy, embryo‐fetal viability, growth, or morphologic development, parturition, maternal care of offspring or postnatal survival, growth, or development. There was no evidence of systemic inflammation in pregnant rats, based on evaluation of serum concentrations of the acute phase proteins alpha‐2‐macroglobulin and alpha‐1‐acid glycoprotein on GD 21. Anthrax lethal toxin‐neutralizing antibodies were detected in AV7909‐vaccinated F0 females. The antibodies were also detected in the sera of fetuses and F1 pups. Exposure of the fetuses and pups to maternally derived anthrax lethal toxin‐neutralizing antibodies was not associated with developmental toxicity.
One‐step preparation of red‐emitting carbon dots for visual and quantitative detection of copper ions
Authors: Wei Jianfei , Hao Dan , Wei Lifei , Zhang Anying , Sun Chenying , Wang Rui 
Published: October 2020

AbstractA one‐step solvothermal method for the preparation of carbon dots with red fluorescence (R‐CDs) was put forward, in which sodium citrate and formamide were chosen as precursors, while formamide was adopted as the solvent. The fluorescence emission peak of the as‐prepared R‐CDs remained the same (600 nm) when the excitation wavelength increased from 490 nm to 560 nm, and the fluorescence quantum yield is 35.3%. Furthermore, the fluorescence intensity of the as‐prepared R‐CDs could be selectively quenched by copper ions, and the mechanism of Cu2+ quenching R‐CDs is the combination of static and dynamic quenching. As a result, the R‐CDs were applied for the construction of a fluorescent sensor without any modification for the quantitative and visual detection of copper ions, which is a typical contaminant in water. The limit of detection for the fluorescent sensor was as low as 5 nmol/L, and it can be used to fast and directly confirm whether the content of copper ions in drinking water meets the criteria of the United States Environmental Protection Agency and the World Health Organization.
An LC–ESI/MS/MS method for the determination of lupeol via precolumn derivatization and its application to pharmacokinetic studies in rat plasma
Authors: Wang Ziming , Wang Yu , Yu Tao , Hu Zhiwei , Wang Yang 
Published: October 2020

AbstractLupeol, a phytosterol and triterpene, is widely found in edible fruits and vegetables, and has been reported to exhibit a spectrum of pharmacological activities against various disease conditions. In the present study, a derivative generated by the reaction of lupeol with p‐toluenesulfonyl isocyanate was ionizable and fragmentable in the negative mode by electrospray ionization/tandem mass spectrometry. Based on this simple chemical derivatization, a liquid chromatography–electrospray ionization/tandem mass spectrometry method was developed and validated for the quantification of lupeol in rat plasma. The calibration curves were linear (r2 > 0.999) over concentrations from 2.5 to 250 ng/ml for lupeol. The method had an accuracy of 96.0–109.4%, and the intra‐ and inter‐day precisions (RSD) were within ± 15%. The stability data showed that no significant degradation occurred under the experimental conditions. The mean recoveries at three quality control levels were within 88.7–95.7%. No significant matrix effects (105.3–109.8%) were observed in rat plasma. This method was successfully applied to the pharmacokinetic study of lupeol in rat plasma after oral administration.
CD200‐CD200R1 signaling pathway regulates neuroinflammation after stroke
Authors: Zhao Shou‐cai , Heng Xu , Ya‐ping Wang , Di Luan , Wen‐qian Wu , Ling‐song Ma , Chu Zhao‐hu , Xu Yang 
Published: October 2020

AbstractObjectiveTo study how the CD200‐CD200R1 signaling pathway modulates poststroke inflammation and advances our knowledge of immune responses to ischemia insults in stroke.MethodsFocal middle cerebral artery occlusion (MCAO) was induced in mice for 90 min, and mice were sacrificed at 1, 3, and 7 days of reperfusion. CD200, CD200R1, iNOS, and Arg‐1 expression in ischemic brains was assessed by Western blotting (WB), and immunohistochemical (IHC) staining was performed to examine the expression of CD200 on neurons and CD200R1 on infiltrating lymphocytes. The severity of neurobehavioral deficits was evaluated by neurological deficit scores (NDS) and infarction volume estimated by TTC staining. To study the relationship between CD200/CD200R1 expression and the diversity of the neuroinflammatory response in stroke, CD200Fc (CD200R1 agonist) was subcutaneously injected at onset, at 1 day and 2 days after MCAO operation, and the brains were collected for detection at 3 days after MCAO/R (reperfusion).ResultsCD200 expression on neurons increased at 1 day and then decreased at 3 days after MCAO/R, and the expression of CD200R1 on lymphocytes showed an opposite temporal pattern as tested by IHC. The WB results showed that CD200/CD200R1 variance exhibited a similar pattern of IHC results, and the level of iNOS peaked at 1 day and then decreased gradually, but Arg‐1 increased with time after MCAO/R in ischemic brains. After CD200Fc injection, CD200R1 expression significantly increased, and CD200Fc promoted Arg‐1 but inhibited iNOS expression. The infarct volume and NDS of the group treated with CD200Fc were significantly smaller than those of the IgG2a‐treated group.ConclusionsThe CD200‐CD200R1 signaling pathway regulates neuroinflammation after stroke. Stimulation of CD200R1 by CD200Fc promotes the anti‐inflammatory response and alleviates ischemic injury.
Microbial biosurfactants: A broad analysis of properties, applications, biosynthesis, and techno‐economical assessment of rhamnolipid production
Authors: Moutinho Liza Fernandes , Moura Felipe Ramalho , Silvestre Rackel Carvalho , Romão‐Dumaresq Aline Silva 
Published: October 2020

AbstractBiosurfactants are surface‐active molecules originated from renewable resources, which are produced by microbial fermentation or chemical/enzymatic catalysis. These molecules present important advantages as compared to petrochemical surfactants, given their resistance to extreme conditions, biodegradability, specificity, and environmental compatibility. Besides that, the high production costs hinder its commercialization. In this way, this article aimed to analyze microbial biosurfactants production, focusing on the optimization of metabolic pathways and production processes, to identify key aspects and provide alternatives to allow a cost‐effective production at industrial scale. This was achieved by a broad analysis of biosurfactants properties, applications, and biosynthetic pathways (in terms of yield, cofactors, and energy), in addition to an assessment of production‐associated costs. As a result of the present extensive data survey and analysis, key production aspects are disclosed. The metabolic pathway yield analysis demonstrated that production of biosurfactants can be significantly improved (highest theoretical yield was 0.47 gbiosurfactant/gsubstrate) by the use of biomolecular engineering techniques to generate optimized synthetic pathways. With an alternative proposed pathway for surfactin, yield was improved and imbalance in cofactors and ATP was reduced. Analysis of productive costs indicated that to make rhamnolipids commercial production feasible, the main efforts should focus on lowering substrate costs as well as the identification of energy‐efficient unit operations to lower electricity cost, since these parameters accounted for 19.36 and 78.22%, respectively, of the production costs. The data generated by this analysis highlight the need for multidisciplinary collaboration to make rhamnolipids economically feasible, including biomolecular engineering and process intensification.
Clinical outcomes of newly diagnosed primary CNS lymphoma treated with ibrutinib‐based combination therapy: A real‐world experience of off‐label ibrutinib use
Authors: Chen Feili , Pang Diwen , Guo Hanguo , Ou Qiuxiang , Wu Xue , Jiang Xinmiao , Wei Xiaojuan , Liu Sichu , Huang Ling , Liang Zhanli , Zhou Dong , Li Wenyu 
Published: October 2020

AbstractIbrutinib‐based combination therapy with high‐dose methotrexate (HD‐MTX) has recently shown clinical activity against relapse/refractory (R/R) primary central nervous system lymphoma (PCNSL). Herein, we report our real‐world experience of treating 11 newly diagnosed PCNSL patients with the ibrutinib/MTX combination. HD‐MTX was given at 3.5 g/m2 every 2‐week for eight doses. Ibrutinib was held upon HD‐MTX infusion until clearance and was administered daily post‐induction until disease progression, intolerable toxicity, or death. Nine out of 11 patients completed the induction phase and received ibrutinib as maintenance therapy. An objective response rate (ORR) of 82% (9/11) was observed including complete response (64%) and partial response (18%). The median progression‐free survival (PFS) was 7.4 months while the median overall survival (OS) was not reached. The ibrutinib/MTX combination was well tolerated in these treatment‐naïve PCNSL patients with an acceptable safety profile. Moreover, the longitudinal analysis of cerebrospinal fluid (CSF) circulating tumor DNA (ctDNA) revealed that CSF ctDNA detection was closely associated with tumor response, and sustained tumor responses correlated with the clearance of ctDNA from the CSF. In sum, our data not only demonstrated the clinical benefit of the ibrutinib and HD‐MTX combination regimen in treating newly diagnosed PCNSL patients in a real‐world setting, but also highlighted the significance of liquid biopsy including CSF ctDNA in tracing tumor burden and assessing treatment response.
Towards Culturally Specific Solutions: Evidence from Ghanaian Kinship Caregivers on Child Neglect Intervention
Authors: Abdullah Alhassan , Frederico Margarita , Cudjoe Ebenezer , Emery Clifton R. 
Published: October 2020

Recognising the signs and finding solutions to the risk and needs of neglected children remains a challenge in child protection practice despite a global increase in the number of reported child neglect cases. This situation is compounded by the impact of cultural practices on how neglect is perceived. Drawing on semi‐structured in‐depth interviews with 31 kinship caregivers, this study sought to explore how the culturally informed traditional kinship care practice in Ghana can be considered an intervention strategy for parental neglect. Proactive intervention, prevention of abandonment and utilisation of family support emerged as ways kinship care practice can help resolve child neglect issues. This study's findings suggest that kinship care options could help prevent severe forms of child neglect and prevent instances of child neglect at their onset. The study highlights the importance of culture and tradition when considering approaches to addressing neglect of children, which could be adapted to other cultures as it provides learning regarding where it is safe to have the extended family involved from the beginning where there is suspected neglect.Key Practitioner Messages

The traditional culturally informed kinship care practice in Ghana provides a proactive solution to address parental neglect.
Child welfare workers should strengthen cultural approaches to address child neglect and support families by providing intervention measures.
Child welfare workers should encourage kin or kith groups to promote reciprocal supportive relationships as this could be useful in providing protection for neglected children.
‘Explore[s] how the culturally informed traditional kinship care practice in Ghana can be considered an intervention strategy for parental neglect’