glass beads
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2022 ◽  
Vol 12 (2) ◽  
pp. 648
Author(s):  
Ionut Avramia ◽  
Sonia Amariei

β-glucan extraction from spent brewer’s yeast is a long process that starts with the lysis of yeast cells, this step lasting up to 36 h and can be disadvantageous when working on a small scale. In this study, a rapid cell rupture method was selected for the lysis of spent brewer’s yeast to obtain β-glucans. Optimal parameters were determined for the lysis of a cellular suspension of spent brewer’s yeast by vortexing with glass beads. Thus, parameters such as the number of 10 min vortex cycles from 1 to 3, the concentration of cell suspension (5, 10, and 15%), and the ratio of yeast/glass beads (1:1, 1:2, and 1:3) were varied in a Box-Behnken design. A cell lysis mechanism using glass beads allows the cell to rupture and permits the removal of intracellular content. An increase in yeast suspension concentration decreased the disruption efficiency, while a proportional increase was observed with the yeast/glass beads ratio and the increasing number of vortexing cycles. The optimal parameters for cell lysis were found to be a cell suspension concentration of 5%, a ratio of yeast/glass beads of 1:2, and a vortexing cycle of 3, with a disruption efficiency of 99.8%. The β-glucan fraction extracted from the optimal sample showed characteristic absorption bands at 1370.77 and 1153.92 cm−1, the content of β-glucan being 78.53%.


Processes ◽  
2022 ◽  
Vol 10 (1) ◽  
pp. 135
Author(s):  
Zhenmin Cheng ◽  
Gang Luo ◽  
Yanling Tang ◽  
Dan Ling ◽  
Zhaoxuan Chen ◽  
...  

Films and rivulets are the two basic forms of dynamic liquid in a three-phase fixed bed (trickle bed), which determines the wetting efficiency of the catalyst. This paper is devoted to the conflicting wetting performance observed between non-porous glass beads and porous alumina pellets, and a parallel zone model is applied to resolve the complex liquid flow texture. This shows that in the case of glass beads, the wetting efficiencies of the catalyst along with the liquid flow rate in increasing and decreasing branches are different, especially when the gas flow rate is low. In comparison, there is almost no wetting difference for the alumina pellets with respect to liquid flow rate increasing or decreasing. The dynamic liquid is significantly more uniformly distributed over the cross-section in the Al2O3 bed than in the glass one.


2022 ◽  
Vol 8 (1) ◽  
Author(s):  
Harunobu Shibao ◽  
Mayako Kutsukake ◽  
Shigeru Matsuyama ◽  
Takema Fukatsu

AbstractSocial insect colonies constantly produce dead insects, which cause sanitary problems and potentially foster deadly pathogens and parasites. Hence, many social insects have evolved a variety of hygienic behaviors to remove cadavers from the colonies. To that end, they have to discriminate dead insects from live ones, where chemical cues should play important roles. In ants, bees and termites, such corpse recognition signals, also referred to as “death pheromones” or “necromones”, have been identified as fatty acids, specifically oleic acid and/or linoleic acid. Meanwhile, there has been no such report on social aphids. Here we attempted to identify the “death pheromone” of a gall-forming social aphid with second instar soldiers, Tuberaphis styraci, by making use of an artificial diet rearing system developed for this species. On the artificial diet plates, soldiers exhibited the typical cleaning behavior, pushing colony wastes with their heads continuously, against dead aphids but not against live aphids. GC-MS and GC-FID analyses revealed a remarkable increase of linoleic acid on the body surface of the dead aphids in comparison with the live aphids. When glass beads coated with either linoleic acid or body surface extract of the dead aphids were placed on the artificial diet plates, soldiers exhibited the cleaning behavior against the glass beads. A series of behavioral assays showed that (i) soldiers exhibit the cleaning behavior more frequently than non-soldiers, (ii) young soldiers perform the cleaning behavior more frequently than old soldiers, and (iii) the higher the concentration of linoleic acid is, the more active cleaning behavior is induced. Analysis of the lipids extracted from the aphids revealed that linoleic acid is mainly derived from phospholipids that constitute the cell membranes. In conclusion, we identified linoleic acid as the corpse recognition factor of the social aphid T. styraci. The commonality of the death pheromones across the divergent social insect groups (Hymenoptera, Blattodea and Hemiptera) highlights that these unsaturated fatty acids are generally produced by enzymatic autolysis of cell membranes after death and therefore amenable to utilization as a reliable signal of dead insects.


2022 ◽  
Vol 102 ◽  
pp. 103123
Author(s):  
Tomasz E. Burghardt ◽  
Anton Pashkevich ◽  
Darko Babić ◽  
Harald Mosböck ◽  
Dario Babić ◽  
...  
Keyword(s):  

Author(s):  
Joanna Then-Obłuska ◽  
Laure Dussubieux

AbstractInternational expeditions extensively excavated Lower Nubia (between the First and Second Nile Cataracts) before it was submerged under the waters of Lake Nasser and Lake Nubia. The expeditions concentrated on monumental architecture and cemeteries, including sites at Qustul and Serra East, where the New Kingdom, and Napatan, Meroitic, Nobadian, and Makurian-period elites and common people were buried, ca. 1400 BC–AD 1400. Although the finds abound in adornments, including bead imports from Egypt and South India/Sri Lanka, only a few traces of local glass bead-making have been recorded in Nubia so far. Based on results of laser ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS) analysis of 76 glass beads, pendants, and chunks from Qustul and Serra East contexts, dated between the New Kingdom and the Makuria Kingdom periods, this paper discusses the composition and provenance of two types of plant-ash soda-lime (v-Na-Ca) glass, two types of mineral soda-lime glass (m-Na-Ca), and two types of mineral-soda-high alumina (m-Na-Al) glass. It also presents the remains of a probable local glass bead-making workshop dated to the period of intensive long-distance bead trade in Northeast Africa, AD 400–600.


Heritage ◽  
2021 ◽  
Vol 4 (4) ◽  
pp. 4542-4557
Author(s):  
Yannick Bruni ◽  
Frédéric Hatert ◽  
Merry Demaude ◽  
Nicolas Delmelle ◽  
Philippe George ◽  
...  

In 1914, a magnificent reliquary cross dating from the early XIIIth century was discovered in a safe from the Liège Cathedral. This double-arm cross shows a wooden structure, covered by gold-coated copper on the front, and by carved silver plates on the back. Its total length is 34 cm, and it is covered by filigrees, gems, glass beads, and pearls on its front. The reliquary cross was analysed by Raman spectrometry and X-ray fluorescence spectrometry (pXRF) to determine the mineralogical and chemical compositions of gems, glass beads, and metals that have been used to decorate it. The results confirm the identification of twenty-five turquoises from Egypt, one garnet from Sri Lanka, as well as six quartz and one opal whose origin is difficult to certify. Twelve glass beads, showing green, blue, or amber tints, were also identified. Their compositions either correspond to soda lime glasses with natron or to potash–lead glasses similar to those of Central Europe. Moreover, a small polished red cross and a green stone appear to be constituted by nice doublets, composed of coloured glass covered by quartz. The filigrees contain Au and Cu, while carved plates covering the edges and the back of the cross are made of silver.


Author(s):  
Siyun Li ◽  
Elise C Fear ◽  
Laura Curiel

Abstract We present a new formulation for a breast tissue-mimicking phantom for combined microwave and ultrasound imaging to assist breast cancer detection. Formulations based on coconut oil, canola oil, agar and glass beads were used to mimic skin and fat tissues. First, 36 recipes were fabricated, and properties were measured to determine the relationship and possible interaction between ingredients with the ultrasound and microwave properties. Based on these results, the formulae were developed to mimic different tissues found in breast, including skin, fat, fibroglandular, and tumour tissues. All phantoms contained a base of agar and glass beads at different proportions depending on the tissue mimicked. Tumour and fibroglandular tissues were best mimicked by adding polyvinylpyrrolidone (PVP), while using coconut oil for skin and canola oil for fat produced the best results. Five final phantoms with different internal structures were fabricated and imaged using B-mode ultrasound and a microwave transmission system. Microwave permittivity maps were obtained from the microwave system and compared to ultrasound images. The structure and composition of the phantoms were all confirmed through this microwave and ultrasound imaging.


2021 ◽  
pp. 60-114
Author(s):  
Ellen Swift ◽  
Jo Stoner ◽  
April Pudsey

The chapter provides a chronological and regional overview of trends in bead jewellery in Egypt from the Roman to late antique periods, and provides both a social interpretation of this material, and insights into wider topics such as trade connections, and the social transformations that occurred in late antiquity. It first sets out the material to be studied. Important data include a substantial number of tomb assemblages from Qau el-Kebir, which are newly context-dated. The chapter then provides an overview of trends, drawing on evidence from individual items, including those preserved exceptionally well through the survival of their original string. A chronological trend from more homogenous to more diverse assemblages is documented, which together with increasing levels of reuse of earlier bead types, and the much greater proportions of non-glass beads seen in the latest assemblages, suggests economic disruptions to production processes. Evidence of trade contacts between Egypt and other areas is documented, including links with Germanic areas, Iran, and the wider Indo-Pacific region. Two more specific investigations follow, first a consideration of ancient coloured string, especially red string, presenting evidence of its apotropaic function, and second an examination of evidence for curation, reuse, and heirloom status in bead assemblages and its interpretation from a social archaeology perspective, in which beads are shown to be important in constructing life course identities and affirming family lineages. It is also demonstrated through bead assemblages and pendants how the cultural lives of people in late antique Egypt show many similarities with other communities across the Byzantine world.


2021 ◽  
Vol 40 (3) ◽  
pp. 329-341
Author(s):  
A. V. Symonenko

During the campaigns of 1951 and 1953 Dmytro Berezovets excavated the Sarmatian graves near the Kut, Hrushivka and Marianske villages of Apostolovski district of Dnipropetrovsk region. These materials were published briefly, without typological and chronological definitions and analysis of the historical context, with illustrations of rather low quality. Moreover, there was some confusion and errors later made by some researchers, including the author, which have been replicated with each reference. Therefore, it is worthy to republish these materials from the standpoint of the current level of the Sarmatian studies in order to correct certain errors as well. Dmytro Berezovets has discovered the assemblages both of Early Sarmatian (Kut, Hrushivka, Maryanske, barrow 3, grave 4) and Middle Sarmatian Age (Marianske, barroow 5, graves 5—7; barrow 5, grave 6; barrow 6, grave 14) according to traditional chronology. All Sarmatian burials under study were the secondary graves in the Bronze Age mounds and Scythian ones. The skeletons lied supine, with their heads directed to Northern sector. Among the grave goods are the Roman and Sarmatiam pottery, simple bronze adornment, cornelian, jade and glass beads, bronze mirror, bone ritual spoon etc. The Early Sarmatian assemblages discovered by Dmytro Berezovets are dated to the late 2nd—1st century BC, the Middle Sarmatiam ones to the 1st—2nd centuries AD. The identical funeral rite of the graves of different date near Marianske once again confirms the validity of the periodization proposed by me in due time, according to which all the graves under study belong to different phases of the first period (phase A2 — Kut, Hrushivka, Marianske, barrow 3, grave 4; phase B — Marianske, barrow 3, graves 5—7; barrow 5, grave 6; barrow 6, grave 14).


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