Single-Edged Knife (Scramasax), 600s, Frankish, Burgundy (?), iron, copper, and gold foil; 36.90 × 4.10 cm (14 1/2 × 1 9/16 inches)

2018 ◽  
pp. 164-167
Keyword(s):  
Author(s):  
M. Talianker ◽  
D.G. Brandon

A new specimen preparation technique for visualizing macromolecules by conventional transmission electron microscopy has been developed. In this technique the biopolymer-molecule is embedded in a thin monocrystalline gold foil. Such embedding can be performed in the following way: the biopolymer is deposited on an epitaxially-grown thin single-crystal gold film. The molecule is then occluded by further epitaxial growth. In such an epitaxial sandwich an occluded molecule is expected to behave as a crystal-lattice defect and give rise to contrast in the electron microscope.The resolution of the method should be limited only by the precision with which the epitaxially grown gold reflects the details of the molecular structure and, in favorable cases, can approach the lattice resolution limit.In order to estimate the strength of the contrast due to the void-effect arising from occlusion of the DNA-molecule in a gold crystal some calculations were performed.


Author(s):  
P.K. Simons

Glycogenosis is defined as any condition in which the tissue concentration of glycogen is increased. There are currently ten recognized variants of glycogenosis that are heritable inborn errors of metabolism. The specific enzymatic defect in each of the variants is known or at least suspected. In all cases, the enzymatic defect prevents the proper metabolism or formation of the glycogen molecule. The clinical and histologic differences between the types of glycogenosis is important to a proper diagnosis after the presence of such a condition is realized. This study was initiated to examine the ultrastructure of the rare Type IV Glycogenosis (Amylopectinosis) of which there is very little morphologic characterization in the literature.Liver tissue was obtained by needle biopsy from a 12-month-old Oriental female who was originally admitted to the hospital after observation of poor development, loss of appetite, and hepatomegaly. The majority of the tissue was fixed for light microscopy in neutral buffered formalin and processed using routine and special staining procedures (reticulin, trichrome, iron, copper, PAS, PAS-diastase and PAS-pectinase.


Catalysts ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 186
Author(s):  
Georgiy B. Shul’pin ◽  
Lidia S. Shul’pina

The review describes articles that provide data on the synthesis and study of the properties of catalysts for the oxidation of alkanes, olefins, and alcohols. These catalysts are polynuclear complexes of iron, copper, osmium, nickel, manganese, cobalt, vanadium. Such complexes for example are: [Fe2(HPTB)(m-OH)(NO3)2](NO3)2·CH3OH·2H2O, where HPTB-¼N,N,N0,N0-tetrakis(2-benzimidazolylmethyl)-2-hydroxo-1,3-diaminopropane; complex [(PhSiO1,5)6]2[CuO]4[NaO0.5]4[dppmO2]2, where dppm-1,1-bis(diphenylphosphino)methane; (2,3-η-1,4-diphenylbut-2-en-1,4-dione)undecacarbonyl triangulotriosmium; phenylsilsesquioxane [(PhSiO1.5)10(CoO)5(NaOH)]; bi- and tri-nuclear oxidovanadium(V) complexes [{VO(OEt)(EtOH)}2(L2)] and [{VO(OMe)(H2O)}3(L3)]·2H2O (L2 = bis(2-hydroxybenzylidene)terephthalohydrazide and L3 = tris(2-hydroxybenzylidene)benzene-1,3,5-tricarbohydrazide); [Mn2L2O3][PF6]2 (L = 1,4,7-trimethyl-1,4,7-triazacyclononane). For comparison, articles are introduced describing catalysts for the oxidation of alkanes and alcohols with peroxides, which are simple metal salts or mononuclear metal complexes. In many cases, polynuclear complexes exhibit higher activity compared to mononuclear complexes and exhibit increased regioselectivity, for example, in the oxidation of linear alkanes. The review contains a description of some of the mechanisms of catalytic reactions. Additionally presented are articles comparing the rates of oxidation of solvents and substrates under oxidizing conditions for various catalyst structures, which allows researchers to conclude about the nature of the oxidizing species. This review is focused on recent works, as well as review articles and own original studies of the authors.


2021 ◽  
pp. 1098612X2110262
Author(s):  
Stacie Summers ◽  
Jonathan Stockman ◽  
Jennifer A Larsen

Objectives The aim of this study was to analyze iron, copper and zinc concentrations in commercial foods and compare among food formats (dry, canned, raw), foods marketed by age category (adult 1+ years and senior 7+ years) and foods intended for adult maintenance vs all life stages. Methods In total, 112 commercial non-therapeutic food products marketed for healthy adult and senior cats were purchased in the USA. Foods were analyzed for their proximate composition. Trace mineral concentrations were measured using inductively coupled argon plasma–optical emission spectroscopy and described on a calculated metabolizable energy basis using standard modified Atwater values. Results Measured iron (median 58.4 mg/1000 kcal [range 15.7–379.0]), copper (median 5.6 mg/1000 kcal [range 0.8–13.3]) and zinc (median 47.6 mg/1000 kcal [range 7.6–128.1]) concentrations were highly variable among cat foods. When all food products – regardless of their nutritional adequacy substantiation method – were compared with the Association of American Feed Control Officials regulatory minimums, 13/112 food products had a mineral deficiency, of which a majority (n = 11/13) were raw food products. Raw foods had significantly lower trace mineral concentrations compared with dry food products and, except for copper, canned food products. Cat foods marketed for senior cats had higher iron ( P = 0.019) and zinc ( P <0.0001) concentrations than foods marketed for adult cats. Foods intended for adult maintenance had higher iron ( P = 0.003) and zinc concentrations than foods intended for all life stages ( P <0.0001). Conclusions and relevance Iron, copper and zinc concentrations in commercial non-therapeutic foods for adult and senior cats are highly variable. A minority of foods – mainly raw food products – were deficient in these minerals. It is unknown if some foods with high trace mineral concentrations could have adverse effects as studies are needed to establish safe upper limits for dietary intake of trace minerals in healthy cats.


1992 ◽  
Vol 25 (3) ◽  
pp. 117-120 ◽  
Author(s):  
T. Bilstad ◽  
M. V. Madland

Leachates from chemical and domestic landfills are defined as hazardous wastewater. Quantitative and qualitative control of leachate can be performed by membrane separation of the total produced leachate volume. Dissolved and suspended solids in the leachate are removed from the major portion of the water phase and either returned to the landfill or further treated. The particle - free permeate meets the effluent requirements for direct discharge to virtually any watercourse. An untreated leachate flow is concentrated thirteen times by tubular type reverse osmosis. The separation efficiencies are 99% for iron, copper, chromium and zinc. For suspended solids the removal is 100%.


2008 ◽  
Vol 49 (41) ◽  
pp. 5961-5964 ◽  
Author(s):  
Chandra M. Rao Volla ◽  
Pierre Vogel

2007 ◽  
Vol 23 ◽  
pp. 119-122
Author(s):  
Cristina Teișanu ◽  
Stefan Gheorghe ◽  
Ion Ciupitu

The most important features of the self-lubricating bearings are the antifriction properties such as friction coefficient and wear resistence and some mechanical properties such as hardness, tensile strength and radial crushing strength. In order to improve these properties new antifriction materials based on iron-copper powders with several additional components (tin, lead and molybdenum disulphide) have been developed by PM techniques. To find the optimal relationship between chemical compositions, antifriction and mechanical properties, in this paper a mathematical model of the sintering process is developed, which highlighted the accordance of the model with data by regression analysis. For the statistical processing of the experimental data the VH5 hardness values of the studied materials were considered. The development of mathematical model includes the enunciation of the model, the establishment of the performance function (optimization) and the establishment of the model equations and verifying. The accordance of the model with experimental data has been highlighted by regression analysis


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