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1.
Bernette Maria Oosterlaken Heiner Friedrich Gijsbertus de With 《Microscopy research and technique》2022,85(1):412-417
Transmission electron microscopy (TEM) is an important analysis technique to visualize (bio)macromolecules and their assemblies, including collagen fibers. Many protocols for TEM sample preparation of collagen involve one or more washing steps to remove excess salts from the dispersion that could hamper analysis when dried on a TEM grid. Such protocols are not standardized and washing times as well as washing solvents vary from procedure to procedure, with each research group typically having their own protocol. Here, we investigate the influence of washing with water, ethanol, but also methanol and 2-propanol, for both mineralized and unmineralized collagen samples via a protocol based on centrifugation. Washing with water maintains the hydrated collagen structure and the characteristic banding pattern can be clearly observed. Conversely, washing with ethanol results in dehydration of the fibrils, often leading to aggregation of the fibers and a less obvious banding pattern, already within 1 min of ethanol exposure. As we show, this process is fully reversible. Similar observations were made for methanol and propanol. Based on these results, a standardized washing protocol for collagenous samples is proposed. 相似文献
2.
Gökelma Mertol Einarsrud Kristian Etienne Tranell Gabriella Friedrich Bernd 《Metallurgical and Materials Transactions B》2020,51(2):850-860
Metallurgical and Materials Transactions B - The quality requirements of aluminum products are steadily increasing, and the presence of non-metallic inclusions have a large impact on the quality of... 相似文献
3.
Kazuo Tsubota Stephen C. Pflugfelder Zuguo Liu Christophe Baudouin Hyo Myung Kim Elisabeth M. Messmer Friedrich Kruse Lingyi Liang Jimena Tatiana Carreno-Galeano Maurizio Rolando Norihiko Yokoi Shigeru Kinoshita Reza Dana 《International journal of molecular sciences》2020,21(23)
Over the past decades, the number of patients with dry eye disease (DED) has increased dramatically. The incidence of DED is higher in Asia than in Europe and North America, suggesting the involvement of cultural or racial factors in DED etiology. Although many definitions of DED have been used, discrepancies exist between the various definitions of dry eye disease (DED) used across the globe. This article presents a clinical consensus on the definition of DED, as formulated in four meetings with global DED experts. The proposed new definition is as follows: “Dry eye is a multifactorial disease characterized by a persistently unstable and/or deficient tear film (TF) causing discomfort and/or visual impairment, accompanied by variable degrees of ocular surface epitheliopathy, inflammation and neurosensory abnormalities.” The key criteria for the diagnosis of DED are unstable TF, inflammation, ocular discomfort and visual impairment. This definition also recommends the assessment of ocular surface epitheliopathy and neurosensory abnormalities in each patient with suspected DED. It is easily applicable in clinical practice and should help practitioners diagnose DED consistently. This consensus definition of DED should also help to guide research and clinical trials that, to date, have been hampered by the lack of an established surrogate endpoint. 相似文献
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We report new measurements of the effective thermal conductivity Keff and relaxation time τ in dilute mixtures of3He in superfluid4He, with molar concentrationsX≤10−3. The temperature range extended fromT≈1.4 K toT
λ. Both Kcff and τ are found to agree with theoretical predictions, in contrast to previous experiments where significant differences
were observed. A new thermal conductivity cell design was used which almost completely eliminates extraneous volumes and surfaces,
and the earlier results are explained in relation to these design changes. 相似文献
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Gaidis M.C. Friedrich S. Segall K. Prober D.E. Szymkowiak A.E. Moseley S.H. 《Applied Superconductivity, IEEE Transactions on》1996,6(1):1-4
We report the development of Nb-Ta-Al-Al2O3-Al superconducting tunnel junction structures for high energy resolution and high efficiency X-ray detection. These devices utilize a Ta X-ray absorber with superconductor “bandgap engineered” quasiparticle trapping to improve charge collection. Experimental results at 0.3 K are presented, showing energy resolution of 102 eV full-width-half-maximum for 6 keV X-rays. Collected charge is in excess of 5×106 electrons. The absorption efficiency is better than 35%. Devices thermally cycle with no change in characteristics 相似文献
10.
Norbert Fischer Siegfried Nitz und Friedrich Drawert 《Zeitschrift für Lebensmitteluntersuchung und -Forschung A》1987,185(3):195-201
Zusammenfassung In grünem (Taiwan Gunpowder) und schwarzem (Ceylon high OP) Tee sind beträchtliche Mengen an Aromastoffen in glykosidischer Bindung vorhanden; ihr Anteil ist sogar höher als der an freien Aromastoffen. Hauptkomponenten sind in beiden Teesorten cis-3-Hexen-1-ol, Benzylalkohol und 2-Phenylethanol in gebundener Form, dazu im Schwarztee Linalool und im grünen Tee Geraniol. Die unterschiedlichen Anteile dieser beiden Terpenalkohole spiegeln die unterschiedlichen Tee-Varietäten wieder, denen die untersuchten Teesorten angehören: der Ceylon-Tee ist der Varietätassamica zuzuordnen, der Tee aus Taiwan der Varietätsinensis. Die Zusammensetzung der aus gebundenen Formen freisetzbaren Aromastoffe war ähnlich komplex wie die der freien Aromastoffe, wobei die Unterschiede zwischen den beiden Teesorten auf den verschiedenen Herstellungsverfahren beruhen. Das Auftreten gebundener Formen solcher Aromastoffe, die nicht originär vorhanden sind, sondern erst während der Welk- oder der Fermentationsphase gebildet werden, impliziert das Vorhandensein glykosidierender Aktivitäten im Teeblatt noch in relativ späten Stadien der Schwarzteeherstellung. Die Untersuchung der gebundenen Anteile an Aromastoffen trägt neben der Analyse der freien Aromastoffe wesentlich zum Verständnis der Reaktionen im Teeblatt wahrend der verschiedenen Produktionsstadien bei.
Auszug aus der Dissertation von N. Fischer, Technische Universitat München 1986
1. Mitteilung Chem Mikrobiol Technol Lebensm 9:87 (1985) 相似文献
Bound flavour compounds in plants 2. Part. Free and bound flavour compounds in green and black tea
Summary Green and black tea contains considerable amounts of flavour compounds which are present in glycosidic bonds, their portion being even higher than that of free flavour compounds. The main components in both of these tea varieties are 3-hexene-1-ol, benzylalcohol and 2-phenylethanol, which are present in the bound forms, and additionally linalool in black tea and geraniol in green tea. The different amounts of these terpene alcohols reflect the different varieties the teas under investigation belong to: the Ceylon tea belongs to the variety assamica, and the Taiwan tea to the variety sinensis. The composition of the flavour compounds liberated from bound forms had a similar complexity to that of the free flavour compounds, the difference being based upon the different production procedures. The occurrence of bound forms of such components that are not originally present but are produced during the withering or fermentation stage implies that glycosidating activities are still present in the tea leaf, even in a relatively late stage of the black tea production process. The investigation of the bound parts of flavour compounds delivers a valuable contribution to a better understanding of the reactions occurring in the tea leaf during the different stages of tea production.
Auszug aus der Dissertation von N. Fischer, Technische Universitat München 1986
1. Mitteilung Chem Mikrobiol Technol Lebensm 9:87 (1985) 相似文献