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11.
Suspension polymerization expands the study of controlled radical polymerization to high conversions and is known as a method to synthesize polymers with high molecular weights. The radical block copolymerizations of styrene (S) and acrylonitrile (AN) or butyl methacrylate (BUMA) controlled by 2,2,6,6‐tetramethylpiperidine‐N‐oxyl (TEMPO) was performed in an oil/water pressure reactor system at a temperature of 125°C. TEMPO‐terminated styrene homopolymer was employed as macroinitiator. The systems were examined by varying the composition of the monomer mixture at a constant reaction time, as well as by varying the reaction time for a characteristic monomer composition to get all of the possible conversion range. The solubility effects of acrylonitrile in the suspension medium were considered. Furthermore, the yield of the reaction was improved through initiator addition by taking control of the reaction. The polymerizations could proceed under control up to a conversion of 80–90%. By using the copolymerization equations, the solubility of pure acrylonitrile in the suspension medium could be calculated and was found to be 8 wt.‐%. 相似文献
12.
Strohm E Herzner G Kaltenpoth M Boland W Schreier P Geiselhardt S Peschke K Schmitt T 《Journal of chemical ecology》2008,34(5):575-583
Females of the European beewolf, Philanthus triangulum, possess a large glove-shaped gland in the head, the postpharyngeal gland (PPG). They apply the content of the PPG to their
prey, paralyzed honeybees, where it delays fungal infestation. Here, we describe the chemical composition of the gland by
using combined GC-MS, GC-FTIR, and derivatization. The PPG of beewolves contains mainly long-chain unsaturated hydrocarbons
(C23–C33), lower amounts of saturated hydrocarbons (C14–C33), and minor amounts of methyl-branched hydrocarbons (C17–C31).
Additionally, the hexane-soluble gland content is comprised of small amounts of an unsaturated C25 alcohol, an unknown sesquiterpene,
an octadecenylmethylester, and several long-chain saturated (C25, C27) and unsaturated (C23–C27) ketones, some of which have
not yet been reported as natural products. Surprisingly, we found a dimorphism with regard to the major component of the PPG
with some females having (Z)-9-pentacosene, whereas others have (Z)-9-heptacosene as their predominant component. The biological relevance of the compounds for the prevention of fungal growth
on the prey and the significance of the chemical dimorphism are discussed. 相似文献
13.
Melanie Kaiser Maria Donatella Semeraro Markus Herrmann Gudrun Absenger Armin Gerger Wilfried Renner 《International journal of molecular sciences》2021,22(13)
Immune functions decline as we age, while the incidence of cancer rises. The advent of immune checkpoint blockade (ICB) has not only revolutionized cancer therapy, but also spawned great interest in identifying predictive biomarkers, since only one third of patients show treatment response. The aging process extensively affects the adaptive immune system and thus T cells, which are the main target of ICB. In this review, we address age-related changes regarding the adaptive immune system with a focus on T cells and their implication on carcinogenesis and ICB. Differences between senescence, exhaustion, and anergy are defined and current knowledge, treatment strategies, and studies exploring T cell aging as a biomarker for ICB are discussed. Finally, novel approaches to improve immunotherapies and to identify biomarkers of response to ICB are presented and their potential is assessed in a comparative analysis. 相似文献
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16.
The management of patents is acknowledged to be closely correlated to a company’s profits. Thus, evaluation of patent portfolios is an essential task for companies producing or depending on technology-related products. While global players and consultants already have considerable experience in this field, no tool has so far been available that meets SME requirements. The Innovation and Patent-Centre at the Chamber of Commerce in Hamburg, a German think tank for patent management, has now developed a tool specially suited for SMEs. The article describes the methodology of the tool and compares it to other state-of-the-art tools. The tool gives an easy-to-understand overview for personnel with different professional backgrounds and facilitates strategic cross-functional discussions. Field tests carried out with SMEs in different industry sectors and with varying patent portfolio sizes and structures have shown good results. 相似文献
17.
Production and processing of foods as core aspects of nutrition-sensitive agriculture and sustainable diets 总被引:1,自引:0,他引:1
Some forms of malnutrition are partly due to agriculture not having nutrient outputs as an explicit goal. A better understanding of what is required from agricultural production and food processing for healthy and sustainable diets is needed. Besides nutritional quality or nutrient output, important factors are: water, soil, health hazards, agrobiodiversity and seasonality. Therefore, possible interactions among constituents of the food chain – human health, the environment, knowledge and education – should be considered from a systemic perspective. Nutrition-sensitive agriculture needs to consider and understand the role of biodiversity in improving dietary quality and dietary diversity as well as seasonality in food supply. Apart from improving agricultural systems in order to close the nutrition gap, efficient storage and food processing technologies to prolong shelf-life are required. If processing is poor, high food losses can cause food insecurity or increase the risk of producing unsafe and unhealthy food. Food storage and processing technologies, particularly at household level, are challenging and often not applicable to traditional crops. In order to achieve the aims of nutrition-sensitive agriculture, it is necessary to comprehend its complexity and the factors that influence it. This will require a trans-disciplinary approach, which will include the three sectors agriculture, nutrition and health at research, extension and political levels. Ensuring that farmers are knowledgeable about production systems, which sustainably provide adequate amounts of nutritious food while conserving the environment is an essential part of nutrition-sensitive agriculture. At the same time, for the benefits of nutrition-sensitive agriculture to be realized, educated consumers are required who understand what constitutes a healthy and sustainable diet. 相似文献
18.
19.
Skuladottir GV Olason PI Jonsson L Skarphedinsson JO Eriksdottir VH Atlason PT Franzson L Schiöth HB 《Lipids》2003,38(11):1127-1132
Hyperphagia was achieved by continuous intracerebroventricular infusion of a melanocortin receptor antagonist (HS024; Neosystem,
Strasbourg, France) in rats. The effects of hyperphagia on FA composition and concentration of plasma phospholipids (PL),
plasma FFA, and adipose tissue TAG were studied in rats for 8 d [short-term hyperphagia (STH); n=8], or 28 d [longterm hyperphagia (LTH); n=9]. The control rats were treated with artificial cerebrospinal fluid for 8 d (n=8) or 28 d (n=10). The rats were fed the same regular diet. In STH rats the plasma PL and fasting plasma FFA contained higher concentrations
of saturated FA (SFA) and monounsaturated FA (MUFA), and plasma FFA contained lower n−6 PUFA than in the control rats. In
LTH rats the plasma PL contained higher concentrations of SFA, MUFA, and n−3 PUFA and higher proportions of 16∶1n−7 and 18∶1n−9
at the expense of 18∶2n−6 than in the control rats. In LTH rats the abundant dietary intake of 18∶2n−6 did not enrich 18∶2n−6
of the plasma PL or adipose tissue TAG. In LTH rats the fasting plasma FFA contained more than twofold higher concentrations
of SFA and MUFA, and higher proportions of 16∶1n−7 and 18∶1n−9 at the expense of 18∶2n−6 than in the control rats. This animal
obesity model shows that LTH affects the FA composition and concentration of plasma PL, plasma FFA, and adipose tissue TAG,
a result consistent with changes associated with increased risk of various diseases in humans. These results also demonstrate
that LTH alters the FA composition of plasma PL and adipose tissue TAG in a way that does not reflect the FA composition of
dietary fat. 相似文献
20.
Florian Echtler Simon Nestler Andreas Dippon Gudrun Klinker 《Personal and Ubiquitous Computing》2009,13(8):609-617
As more interactive surfaces enter public life, casual interactions from passersby are bound to increase. Most of these users
can be expected to carry a mobile phone or PDA, which nowadays offers significant computing capabilities of its own. This
offers new possibilities for interaction between these users’ private displays and large public ones. In this paper, we present
a system that supports such casual interactions. We first explore a method to track mobile phones that are placed on a horizontal
interactive surface by examining the shadows which are cast on the surface. This approach detects the presence of a mobile
device, as opposed to any other opaque object, through the signal strength emitted by the built-in Bluetooth transceiver without
requiring any modifications to the devices’ software or hardware. We then go on to investigate interaction between a Sudoku
game running in parallel on the public display and on mobile devices carried by passing users. Mobile users can join a running
game by placing their devices on a designated area. The only requirement is that the device is in discoverable Bluetooth mode.
After a specific device has been recognized, a client software is sent to the device which then enables the user to interact
with the running game. Finally, we explore the results of a study which we conducted to determine the effectiveness and intrusiveness
of interactions between users on the tabletop and users with mobile devices. 相似文献