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61.
The properties of carbon fibers modified by aqueous electrochemical synthesis of pyrrole has been determined by using the dynamic contact angle analyzer (DCA), scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR). Electrochemical process parameters such as the initial pyrrole concentration, electrolyte concentration, applied voltage, electrolyte type, and reaction time were systematically varied, and their impact on the polypyrrole–carbon fiber interphases surface free energy and morphology was ascertained. The surface free energies of the polypyrrole–carbon fiber interphases were obtained by using single fiber filaments. SEM analysis of the interphases revealed several distinct surface structures, including smooth, porous, granular, microspheroidal, and leafoidal morphologies. The noncoated but commercially surface oxidized carbon fibers have smooth surface morphology with occasional longitudinal striations. FTIR analysis of the polypyrrole interphases confirmed that the counterions derived from the electrolytes were incorporated into the film. The surface free energies of the electrochemically formed polypyrrole–carbon fiber interphases equivalent to 60–75 dynes/cm, was determined to be up to 40% higher than that for the surface oxidized but unsized carbon fibers equivalent to 50 dynes/cm. This improvement in the surface free energies of the polypyrrole–carbon fiber interphases suggests easy wettability by polymer matrices such as epoxy resin, γ ˜ 47 dynes/cm and, polyimide matrix, γ ˜ 45 dynes/cm. © 1996 John Wiley & Sons, Inc. 相似文献
62.
The imidization of polymerizable reactive mixtures, PMR-15 has been performed in a vacuum oven at isothermal aging temperatures ranging from 65 to 200°C for aging periods of 0.5 to 2.5 h. The weight loss of the resin and chemical changes that occurred as a result of aging were monitored gravimetrically and by FT-IR spectroscopy. Differential scanning calorimetry was used to determine the temperature at which imidization took place. Imidization was observed to commence at 65°C after long aging times, t ≥ 2.5 h and at ∼95°C at a shorter time, t ∼0.5 h. At higher aging temperatures of 135 to 165°C, extensive imidization occurred. This was shown by the dramatic increase in imide absorption bands at 1780 and 1380 cm−1. Beyond 165°C, there were no significant changes in the imide absorption bands, suggesting that imidization was nearly complete. The activation energy for isothermal aging was determined from the slope of the log of the rate of weight loss vs 1/T curve to be ∼4.5 kJ/mol and is lower than the average activation energy for imidization ∼43 kJ/mol obtained from the plot of the log of the rate of increase of the imide carbonyl peak absorption at 1780 cm−1 vs 1/T. 相似文献
63.
Maringeles Clauzure Mnica A. Tquez Delgado Jude M. Phillip Maria V. Revuelta Leandro Cerchietti Vanina A. Medina 《International journal of molecular sciences》2022,23(3)
The discovery of the human histamine H4 receptor (H4R) has contributed to our understanding of the role of histamine in numerous physiological and pathological conditions, including tumor development and progression. The lymph nodes of patients with malignant lymphomas have shown to contain high levels of histamine, however, less is known regarding the expression and function of the H4R in T-cell lymphoma (TCL). In this work we demonstrate the expression of H4R isoforms (mRNA and protein) in three human aggressive TCL (OCI-Ly12, Karpas 299, and HuT78). Histamine and specific H4R agonists (VUF8430 and JNJ28610244) significantly reduced cell viability in a dose-dependent manner (p < 0.05). The combined treatment with the H4R antagonist (JNJ7777120, 10 µM) reversed the effects of the H4R ligands. Importantly, we screened a drug repurposing library of 433 FDA-approved compounds (1 μM) in combination with histamine (10 μM) in Hut78 cells. Histamine produced a favorable antitumor effect with 18 of these compounds, including the histone deacetylase inhibitor panobinostat. Apoptosis, proliferation, and oxidative stress studies confirmed the antitumoral effects of the combination. We conclude that the H4R is expressed in TCL, and it is involved in histamine-mediated responses. 相似文献
64.
Oxidative stress has been implicated as a primary or secondary player to numerous diseases. A potential approach to control oxidative stress induced diseases is to deliver small antioxidant compounds to compromised sites at equivalent rates of reactive oxygen species (ROS) generation. This becomes a complicated task as antioxidant molecules typically have poor bioavailability and stability. Antioxidants synthesized into poly(beta-amino ester) (PBAE) crosslinked polymers have shown improved delivery by enhancing stability while allowing controlled release through hydrolysis. The tunable crosslinked networks show significant response to specific oxidizing environments, where free radicals can be present. Curcumin conjugated PBAE bulk films have proportional rates of accelerated degradation, thus faster release of curcumin, in a range of low concentrations of hydrogen peroxide (H2O2), where 2′2-azobis(2-amidinopropane) dihydrochloride has no substantial impact. This effect suggests the possibility to create a system that releases its therapeutic agent in direct relationship to the need through ROS signaling. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48647. 相似文献
65.
Anderson Ryan Terrell Jordan Schneider Judy Thompson Sean Gradl Paul 《Metallurgical and Materials Transactions B》2019,50(4):1921-1930
Metallurgical and Materials Transactions B - Various additive manufacturing processes are being evaluated to reduce the time and cost for fabrication of low volume, complex, and multifunctional... 相似文献
66.
Kieran Jordan Marion Dalmasso Juergen Zentek Anneluise Mader Geert Bruggeman John Wallace Dario De Medici Alfonsina Fiore Estella Prukner‐Radovcic Maja Lukac Lars Axelsson Askild Holck Hanne Ingmer Mindaugas Malakauskas 《Journal of the science of food and agriculture》2014,94(15):3079-3089
Foodborne illness continues as a considerable threat to public health. Despite improved hygiene management systems and increased regulation, pathogenic bacteria still contaminate food, causing sporadic cases of illness and disease outbreaks worldwide. For many centuries, microbial antagonism has been used in food processing to improve food safety. An understanding of the mode of action of this microbial antagonism has been gained in recent years and potential applications in food and feed safety are now being explored. This review focuses on the potential opportunities presented, and the limitations, of using microbial antagonism as a biocontrol mechanism to reduce contamination along the food chain; including animal feed as its first link. © 2014 Society of Chemical Industry 相似文献
67.
Chandran Vikas Kalman Jordan Fayazbakhsh Kazem Bougherara Habiba 《Journal of Mechanical Science and Technology》2021,35(5):1977-1985
Journal of Mechanical Science and Technology - This research work presents a comparative study of the tensile properties of polylactic acid (PLA) specimens per ASTM D638-14 fabricated by... 相似文献
68.
Sharon Hausman-Cohen William LaValley Heather Way Emily Gutierrez Jordan Reeder 《International journal of molecular sciences》2022,23(4)
Molecular biology combined with genomics can be a powerful tool for developing potential intervention strategies for improving outcomes in children with autism spectrum disorders (ASD). Monogenic etiologies rarely cause autism. Instead, ASD is more frequently due to many polygenic contributing factors interacting with each other, combined with the epigenetic effects of diet, lifestyle, and environment. One limitation of genomics has been identifying ways of responding to each identified gene variant to translate the information to something clinically useful. This paper will illustrate how understanding the function of a gene and the effects of a reported variant on a molecular level can be used to develop actionable and targeted potential interventions for a gene variant or combinations of variants. For illustrative purposes, this communication highlights a specific genomic variant, SHANK3. The steps involved in developing molecularly genomically targeted actionable interventions will be demonstrated. Cases will be shared to support the efficacy of this strategy and to show how clinicians utilized these targeted interventions to improve ASD-related symptoms significantly. The presented approach demonstrates the utility of genomics as a part of clinical decision-making. 相似文献
69.
Medicare/Medicaid billing fraud and abuse can be prosecuted under a wider array of laws than apply within the private sector. Cases are typically initiated by whistleblowers or through detection of unusual billing patterns. Few psychologists in independent practice have ever been convicted of Medicare/Medicaid billing fraud or abuse, but government antifraud efforts against psychologists appear to be on the rise. These efforts are pursued under the auspices of containing spiraling health care costs, but they can uncover unintentional billing abuse by psychologists, arising from general ignorance of claim-processing procedures, lack of uniformity across insurance programs, constantly changing guidelines, and ambiguous interpretations. Recent investigations in south Texas have especially targeted the use of extenders for psychological and neuropsychological testing. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
70.