A molecular explanation for the origin of bound rubber in carbon black filled rubber compounds

Some of the theories that have been developed to explain the origin of bound rubber are critically reviewed and discussed with respect to published data. Theories for carbon black filled compounds and for silica–silicone rubber mixtures are considered; the phenomena involved are likely to be very different, with clear chemical aspects for the latter systems. A common feature emerges, however, from these theories: the area of the polymer–filler interaction site, which is generally considered as a fitting parameter in most approaches. This article concentrates on this aspect and suggests that, with respect to recent findings about the very surface of carbon black particles, an explanation for bound rubber can be offered that considers strong topological constraints exerted by the filler surface on rubber segments. Calculations of interaction site area made with experimental data give values close to a fraction of the half-lateral surface of the structural unit representative of the rubber considered. It follows that the bound rubber variation during storage can now be understood by considering a slow replacement of short rubber chains initially adsorbed on filler particles by larger ones, as demonstrated by calculated data. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 66: 2257–2268, 1997     

Nanocarrier-Based Delivery of SN22 as a Tocopheryl Oxamate Prodrug Achieves Rapid Tumor Regression and Extends Survival in High-Risk Neuroblastoma Models

Despite the use of intensive multimodality therapy, the majority of high-risk neuroblastoma (NB) patients do not survive. Without significant improvements in delivery strategies, anticancer agents used as a first-line treatment for high-risk tumors often fail to provide clinically meaningful results in the settings of disseminated, recurrent, or refractory disease. By enhancing pharmacological selectivity, favorably shifting biodistribution, strengthening tumor cell killing potency, and overcoming drug resistance, nanocarrier-mediated delivery of topoisomerase I inhibitors of the camptothecin family has the potential to dramatically improve treatment efficacy and minimize side effects. In this study, a structurally enhanced camptothecin analog, SN22, reversibly coupled with a redox-silent tocol derivative (tocopheryl oxamate) to allow its optimally stable encapsulation and controlled release from PEGylated sub-100 nm nanoparticles (NP), exhibited strong NB cell growth inhibitory activity, translating into rapid regression and durably suppressed regrowth of orthotopic, MYCN-amplified NB tumors. The robust antitumor effects and markedly extended survival achieved in preclinical models recapitulating different phases of high-risk disease (at diagnosis vs. at relapse with an acquired loss of p53 function after intensive multiagent chemotherapy) demonstrate remarkable potential of SN22 delivered in the form of a hydrolytically cleavable superhydrophobic prodrug encapsulated in biodegradable nanocarriers as an experimental strategy for treating refractory solid tumors in high-risk cancer patients.     

Epoxy/imidazolium-based ionic liquid systems: The effect of the hardener on the curing behavior,thermal stability,and microwave absorbing properties

A new transparent microwave absorbing coating was developed by compounding 1-butyl-3-methyl imidazolium tetrafluoroborate (bmim.BF₄) ionic liquid (IL) with diglycidyl ether of bisphenol A-type epoxy resin. The systems were crosslinked with the IL alone or combined with conventional hardeners, as anhydride or aromatic amine. The curing behavior was investigated by thermal and spectroscopic analysis performed at high temperatures. Neat bmim.BF₄ was able to cure epoxy resin, giving rise to networks with outstanding thermal stability compared with the systems cured with anhydride or aromatic amine. bmim.BF₄ accelerated the curing process in the presence of aromatic amine but retarded this event when anhydride was used as an external curing agent. The glass-transition temperature evaluated by dynamic mechanical analysis decreased when the amount of IL increased, which can be attributed to side reactions during the curing process, as well as the plasticizing effect of IL. The epoxy networks cured with bmim.BF₄ alone or in combination with anhydride or aromatic amine were transparent and presented considerable microwave absorbing properties in the X-band frequency range (8–12 GHz), being the best performance observed for the systems cured with bmim.BF4/anhydride curing system, with reflection loss value around −16 dB at 11.3 GHz. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48326.     

Development of active cassava starch cellulose nanofiber-based films incorporated with natural antimicrobial tea tree essential oil

In the present study, a cassava starch-glycerol film with reinforcement of Pinus sp. nanofibers (NFC) incorporated with tea tree (Melaleuca alternifolia) essential oil (TTO) were prepared by casting technique. The physical (barrier, mechanical, and optical), structural, and antimicrobial properties of the films were evaluated and compared with the control films. Films with 0.08% TTO exhibited a significant increase in the tensile strength (TS) while films with 1.5% TTO showed a decrease in TS, suggesting a crosslinking effect. The addition of 1.5% TTO reduced the water vapor permeability values in 43% comparing to the control films. Analysis obtained by Fourier transform infrared spectroscopy showed bands related to the interaction between TTO and matrix for films with 1.5% TTO and 0.3% NFC. This film was effective against Staphylococcus aureus and Candida albicans which could be applied for several packaging purposes. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48726.     

Alcohol consumption, smoking urge, and the reinforcing effects of cigarettes: An ecological study.

Smokers (N=74) who volunteered for a smoking cessation study monitored their daily experiences for up to 6 weeks prior to the quit date. Self-reports from 7,707 diary records were used to examine the associations among alcohol consumption (present in 607 diary records), situational factors, smoking, urge to smoke, and subjective consequences of smoking. Alcohol use, smoking urge, and the subjective effects of smoking were context dependent. Momentary reports of smoking and alcohol consumption were associated with one another. Alcohol use predicted smoking even when contextual factors were covaried. Alcohol use was associated with more frequent reports of urge to smoke. Alcohol was also associated with more frequent reports that the last cigarette produced a rush/buzz, was good tasting, and reduced the urge. However, effects for rush/buzz and urge reduction were qualified by interactions between alcohol use and the latency since smoking. Rush/buzz tended to be associated with alcohol use, regardless of smoking recency. Alcohol was associated with urge reduction only when the cigarette being appraised was smoked more than 15 minutes prior to the diary entry. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Aesthetics, Death, and Landmark Structures: Approach for Values Clarification

The Golden Gate Bridge is an iconic landmark, which has long held the distinction of being the most popular structure in the world to commit suicide. A general process is presented for policy makers’ use to generate conversation and clarify their values in making decisions about public works improvements. This applies particularly well where issues of aesthetics and cost are emotionally and politically charged. The Golden Gate Bridge serves as a case study of how this process can be used. Three design solutions were generated on the basis of architectural concerns and developed in the context of evaluation criteria. A value-based decision analysis approach was taken to determine the preference structure of decision makers involved and to provide a rational framework for further development. Results indicate that existing preferences among decision makers may not be consistent with their public decisions and could be clarified given a more rigorous framework. The do-nothing option is likely to be less preferred to other options given a thorough definition of the acceptance criteria.     

Estimated dietary exposure to principal food mycotoxins from The First French Total Diet Study

This study reports estimates on dietary exposure from the first French Total Diet Study (FTDS) and compares these estimates with both existing tolerable daily intakes for these toxins and the intakes calculated during previous French studies. To estimate the dietary exposure of the French population to the principal mycotoxins in the French diet (as consumed), 456 composite samples were prepared from 2280 individual samples and analysed for aflatoxins, ochratoxin A, trichothecenes, zearalenone, fumonisins and patulin. Average and high percentile intakes were calculated taking account of different eating patterns for adults, children and vegetarians. The results showed that contaminant levels observed in the foods examined 'as consumed' complied fully with current European legislation. However, particular attention needs to be paid to the exposure of specific population groups, such as children and vegans/macrobiotics, who could be exposed to certain mycotoxins in quantities that exceed the tolerable or weekly daily intake levels. This observation is particularly relevant with respect to ochratoxin A, deoxynivalenol and zearalenone. For these mycotoxins, cereals and cereal products were the main contributors to high exposure.     

Determination of several elements in duplicate meals from catering establishments using closed vessel microwave digestion with inductively coupled plasma mass spectrometry detection: estimation of daily dietary intake

An estimation of the dietary exposure of French consumers to 21 essential and non-essential mineral elements using duplicate meals (breakfast and lunch) purchased from catering establishments was investigated after digestion by a closed vessel microwave procedure and quantification by ICP-MS. Daily dietary exposure estimates for metals and minerals were compared with the Provisional Tolerable Weekly Intakes (PTWI), the Tolerable Daily Intake (TDI) or the Acceptable Daily Intakes (ADI), as established by the FAO/WHO to estimate the risk of toxicity, and the US Recommended Daily Allowances (US RDA) or the Estimate Safe & Adequate Daily Dietary Intakes (ESADDI). Moreover, comparisons were made with those from previous French studies as well as those from other countries. The estimated mean daily intakes were 11 μg for lithium, 3.42 g for sodium, 192 mg for magnesium, 2.03 mg for aluminium, 3.64 g for potassium, 642 mg for calcium, 154 μg for chromium, 12.3 mg for iron, 2.15 mg for manganese, 4 μg for cobalt, 74 μg for nickel, 925 μg for copper, 10.2 mg for zinc, 147 μg for arsenic, 66 μg for selenium, 112 μg for molybdenum, 3.6 μg for cadmium, 2.32 mg for tin, 3 μg for antimony, 9 μg for mercury and 34 μg for lead. For the non-essential (toxic) elements, aluminium, tin, antimony, cadmium, arsenic, mercury and lead, the daily intake estimates were far below tolerable limits; and similar or somewhat lower than their respective PTWI, ADI, TDI, ESADDI and US RDA for individual minerals and essential trace elements, with good agreement with other country studies. The performance of the multi-elemental ICP-MS technique was also evaluated.     

A multi‐ontology framework to guide agriculture and food towards diet and health

Global increases in metabolic diseases that can be influenced by diet have re‐emphasized the importance of considering how different foods can improve human health. The entire agricultural enterprise has an unprecedented opportunity to increase its value by producing foods that improve the health of consumers. Research efforts in agriculture/food science/nutrition are endeavoring to do so, although little tangible success has been achieved. At the core of the problem is a failure to define the goal itself: health. Health, as a scientifically measurable concept, is poorly defined relative to disease, and yet consensus‐based, curated vocabularies that describe the multiple variations in human health in useful terms are critical to unifying the scientific fields related to agriculture and nutrition. Each of the life‐science disciplines relating to health has developed databases, thesauri, and/or ontologies to capture such knowledge. High‐throughput and ‐omic technologies are expanding both the amount and heterogeneity of available information. Unfortunately, the language used to describe substantially similar (even logically equivalent) concepts is often different between information systems. Increasing the future value of agriculture, therefore, will depend on creating a process for generating common ontologies of the concept of health, and guiding the development of a common language. This paper illustrates a framework for integrating heterogeneous ontologies into interdisciplinary, foods‐for‐health knowledge systems. A common system of language that describes health and is shared by all the life‐science disciplines will provide immediate benefits in terms of increased health‐claim regulatory efficiencies and predictive functions for individualized diets. Ultimately, these vocabularies will guide agriculture to its next goal of producing health‐enhancing foods. Copyright © 2007 Society of Chemical Industry