57 research outputs found
Mechanisms by which statins protect endothelial cells from radiation-induced injury in the carotid artery
BackgroundThe incidental use of statins during radiation therapy has been associated with a reduced long-term risk of developing atherosclerotic cardiovascular disease. However, the mechanisms by which statins protect the vasculature from irradiation injury remain poorly understood.ObjectivesIdentify the mechanisms by which the hydrophilic and lipophilic statins pravastatin and atorvastatin preserve endothelial function after irradiation.MethodsCultured human coronary and umbilical vein endothelial cells irradiated with 4 Gy and mice subjected to 12 Gy head-and-neck irradiation were pretreated with statins and tested for endothelial dysfunction, nitric oxide production, oxidative stress, and various mitochondrial phenotypes at 24 and 240 h after irradiation.ResultsBoth pravastatin (hydrophilic) and atorvastatin (lipophilic) were sufficient to prevent the loss of endothelium-dependent relaxation of arteries after head-and-neck irradiation, preserve the production of nitric oxide by endothelial cells, and suppress the cytosolic reactive oxidative stress associated with irradiation. However, only pravastatin inhibited irradiation-induced production of mitochondrial superoxide; damage to the mitochondrial DNA; loss of electron transport chain activity; and expression of inflammatory markers.ConclusionsOur findings reveal some mechanistic underpinnings of the vasoprotective effects of statins after irradiation. Whereas both pravastatin and atorvastatin can shield from endothelial dysfunction after irradiation, pravastatin additionally suppresses mitochondrial injury and inflammatory responses involving mitochondria. Clinical follow-up studies will be necessary to determine whether hydrophilic statins are more effective than their lipophilic counterparts in reducing the risk of cardiovascular disease in patients undergoing radiation therapy
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Re‐evaluation of celluloses E 460(i), E 460(ii), E 461, E 462, E 463, E 464, E 465, E 466, E 468 and E 469 as food additives
Following a request from the European Commission, the EFSA Panel on Food Additives and Nutrient sources added to Food (ANS) was asked to deliver a scientific opinion on the re-evaluation of microcrystalline cellulose (E 460(i)), powdered cellulose (E 460(ii)), methyl cellulose (E 461), ethyl cellulose (E 462), hydroxypropyl cellulose (E 463), hydroxypropyl methyl cellulose (E 464), ethyl methyl cellulose (E 465), sodium carboxy methyl cellulose (E 466) and enzymatically hydrolysed carboxy methyl cellulose (E 469) as food additives. The Joint FAO/WHO Expert Committee on Food Additives (JECFA) and the Scientific Committee on Food (SCF) established an acceptable daily intake (ADI) ‘not specified’ for unmodified and modified celluloses. Celluloses are not absorbed and are excreted intact in the faeces; in addition, microcrystalline cellulose, powdered and modified celluloses could be fermented by the intestinal flora in animals and humans. Specific toxicity data were not always available for all the celluloses evaluated in the present opinion and for all endpoints. Given their structural, physicochemical and biological similarities, the Panel considered it possible to read-across between all the celluloses. The acute toxicity of celluloses was low and there was no genotoxic concern. Short-term and subchronic dietary toxicity studies performed with E 460(i), E 461, E 462, E 463, E 464, E 466 and E 469 at levels up to 10% did not indicate specific treatment related adverse effects. In chronic toxicity studies performed with E 460(i), E 461, E 463, E 464, E 465 and E 466, the no observed adverse effect level (NOAEL) values reported ranged up to 9,000 mg/kg body weight (bw) per day. No carcinogenic properties were detected for microcrystalline cellulose and modified celluloses. Adverse effects on reproductive performance or developmental effects were not observed with celluloses at doses greater than 1,000 mg/kg bw by gavage (often the highest dose tested). The combined exposure to celluloses (E 460–466, E 468 and E 469) at 95th percentile of the refined (brand-loyal) exposure assessment for the general population was up to 506 mg/kg bw per day. The Panel concluded that there was no need for a numerical ADI and that there would be no safety concern at the reported uses and use levels for the unmodified and modified celluloses (E 460(i); E 460(ii); E 461–466; E 468 and E 469). The Panel considered an indicative total exposure of around 660–900 mg/kg bw per day for microcrystalline, powdered and modified celluloses
Translation: Female Batik Worker
This image was captured in 2016 during my thesis research project in Javanese batik, which was recognized in 2009 by UNESCO as a masterpiece of human heritage. Batik usually takes the form of patterned woven cloth, created by using canting or a wax pen to cover the parts of the fabric that tend to resist dyeing or color during the process. Its diverse patterns demonstrate cultural diversity and symbolize Indonesia's historically complex religious views, cultures, and ethnic identities. Though Javanese are the most likely Indonesians to wear and promote batik, it remains present in most Indonesian communities and at least 18 Indonesian provinces. By creating solidarity across this broad number of different ethnic groups, batik has gained a reputation as a tool for strengthening cultural heritage and nation-building. This sense of belonging plays a significant role in providing cultural continuity, while making a notable contribution to the country's economy. This image is of a female worker in a batik "Sri Kuncoro" workshop that is located in a village called Wukirsari - Giriloyo in Imogiri, Yogyakarta, Indonesia
Heterogeneous glycopeptides from gastric mucin inhibit dental decay in rats a pilot study
Influence of needle pulse shifting on the basis pulse for wire-EDM of hard metals
The needle pulse can be shifted by the modular structure of the process energy source on a basis ignition pulse. In the Paper is presented that one basis pulse in connection with a needle pulse an improved roughness can be achieved. The simulation of the thermal influence of the needle-basis pulse-combination shows the influences of the pre-burning-duration and/or the past-burning-duration on the needle pulse. The result shows that the needle pulse shifts are efficient only in selected time ranges. At REM pictures typical surface textures are shown, which can occur by the needle pulse shift
Improved cemented carbide properties after wire-EDM by pulse shaping”, Journal of materials processing technology
Abstract In many applications the wire-EDM of cemented carbides (WEDM) (WC-(TiC)-Co) is restricted by the basic properties of this family of materials. Therefore, this research was aimed at developing an optimal process energy source that produces improved material properties after WEDM. The studies showed that it is important to use the correct parameter selection for main-cut and post-cut. Deterioration in the material properties by processing with high pulse energies can be corrected only by a limited extent in the post-cut. The primary actuating variable of pulse is the pulse duration, i.e. with pulse duration <500 ns higher current magnitudes can also be used without problems. Through the use of a new process energy source increase of bending strength of average 30% could be achieved. Simulation of the pulse waveforms and how the thermal load of the cut surface can be reduced and the technical conditions can be adapted to a particular application are shown in this paper
Thermo-chemische Behandlung von Leiterplatten zur vermehrten Rückgewinnung von Tantal
Technologiemetalle wie Tantal sind essenzieller Bestandteil vieler Schlüsseltechnologien. Das Refraktärmetall wird hauptsächlich in der Elektro- und Elektronikindustrie in Form von Tantalkondensatoren eingesetzt. Diese zeichnen sich durch ihre hohe spezifische Kapazität aus und sind daher prädestiniert für den Einsatz in platzkritischen Anwendungen. Bislang wird Tantal allerdings nicht aus obsolten Elektro- und Elektronikgeräten zurückgewonnen. In dieser Arbeit werden die Einsatzmöglichkeiten der thermo-chemischen Behandlung zur Rückgewinnung von Tantal aus Leiterplatten untersucht. Ziel der Arbeit war die Gewinnung einer Fraktion, in der Tantal möglichst vollständig und stark konzentriert enthalten ist. Gleichzeitig soll die Rückgewinnung von Tantal nicht zu Lasten anderer Elemente gehen, insbesondere nicht zu Lasten von Edelmetallen, die einen hohen Wertinhalt aufweisen. In einem ersten thermo-chemischen Behandlungsschritt wurde bei 650 °C und unter Stickstoffatmosphäre der Kunststoffanteil der Leiterplatten zersetzt. Gleichzeitig zerfielen durch die Hitzeeinwirkung die gesinterten Anodenblöcke der Tantalkondensatoren in ein feines Pulver. Durch die Weiterbehandlung des festen Produktes mittels Siebklassierung sammelten sich 56,0 Ma.-% des gesamten Tantals in der Siebfraktion 0 - 0,063 mm, welche zu 24,1 Ma.-% aus Tantal bestand. Wurde das feste Produkt gemahlen und erst anschließend gesiebt, waren 75,0 Ma.-% des gesamten Tantals in der Siebfraktion 0 - 0,063 mm enthalten. Weil durch das Mahlen allerdings alle hart-spröden Materialien zerkleinert wurden, wurde das Tantal verdünnt und seine Konzentration betrug hier lediglich 1,5 Ma.-%. Die Versuchsergebnisse zeigen, dass die thermo-chemische Behandlung einen wichtigen Beitrag zum Recycling von Tantal aus end-of-life Leiterplatten leisten kann. Durch die Weiterbehandlung des festen Produktes erscheint es möglich, Technologiemetalle wie Tantal wirtschaftlich zurückzugewinnen und so einen Beitrag zur Sicherung der Rohstoffbasis und zum Schutz der Umwelt zu leisten
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