scholarly journals Atlas of Micromorphological Degradation of Archaeological Birch Bark

2021 ◽  
Vol 11 (18) ◽  
pp. 8721
Author(s):  
Johanna Klügl ◽  
Giovanna Di Pietro
Keyword(s):  
Colour Change ◽  
Morphological Characteristics ◽  
Microscopic Analysis ◽  
Birch Bark ◽  
Macroscopic Appearance ◽  
Contemporary Sample ◽  
Transmission Electron ◽  
Microscopic Features ◽  
Colour Changes ◽  
Microscopic Feature

In this paper we present an atlas of micromorphological degradation of archaeological birch bark for the first time. We analysed the morphology of 13 samples extracted from ice-logged, waterlogged and cave-retrieved objects dated from the Neolithic to the Middle Age by means of light microscopy (LM) and transmission electron microscopy (TEM). We then compared their morphology to that of a contemporary sample, both intact and decayed. In all samples, 13 morphological characteristics that can be associated with fungal, bacterial, chemical, mechanical and light degradation are defined and described, and example LM and TEM images are provided. This novel atlas provides conservator-restorers a much-needed tool to relate the macroscopic appearance to the microscopic structure of birch bark objects. The most important macroscopic features allowing estimation of the state of preservation at the cell level are colour changes, loss of pliability, presence of delamination and increased brittleness. Colour change and delamination can be connected to microscopic features, and microscopic analysis can trace whether they were caused by biotic, chemical or physical decay. However, increased brittleness cannot be connected to a specific microscopic feature.

scholarly journals Alteration of Tissue Marking Dyes Depends on Used Chromogen during Immunohistochemistry

Cells ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 835
Author(s):  
Selina Kiefer ◽  
Julia Huber ◽  
Hannah Füllgraf ◽  
Kristin Sörensen ◽  
Agnes Csanadi ◽  
...  
Keyword(s):  
Colour Change ◽  
Residual Tumour ◽  
Blue Colour ◽  
Close Margin ◽  
Correct Orientation ◽  
Therapeutic Regime ◽  
Colour Changes ◽  
Tissue Specimens ◽  
Immunohistochemical Analyses ◽  
Colour Signal

Pathological biopsy protocols require tissue marking dye (TMD) for orientation. In some cases (e.g., close margin), additional immunohistochemical analyses can be necessary. Therefore, the correlation between the applied TMD during macroscopy and the examined TMD during microscopy is crucial for the correct orientation, the residual tumour status and the subsequent therapeutic regime. In this context, our group observed colour changes during routine immunohistochemistry. Tissue specimens were marked with various TMD and processed by two different methods. TMD (blue, red, black, yellow and green) obtained from three different providers (A, B and C, and Whiteout/Tipp-Ex®) were used. Immunohistochemistry was performed manually via stepwise omission of reagents to identify the colour changing mechanism. Blue colour from provider A changed during immunohistochemistry into black, when 3,3′-Diaminobenzidine-tetrahydrochloride-dihydrate (DAB) and H2O2 was applied as an immunoperoxidase-based terminal colour signal. No other applied reagents, nor tissue texture or processing showed any influence on the colour. The remaining colours from provider A and the other colours did not show any changes during immunohistochemistry. Our results demonstrate an interesting and important pitfall in routine immunohistochemistry-based diagnostics that pathologists should be aware of. Furthermore, the chemical rationale behind the observed misleading colour change is discussed.

scholarly journals Indicator Layers Based on Ethylene-Vinyl Acetate Copolymer (EVA) and Dicyanovinyl Azobenzene Dyes for Fast and Selective Evaluation of Vaporous Biogenic Amines

Sensors ◽  
2018 ◽  
Vol 18 (12) ◽  
pp. 4361
Author(s):  
Tinkara Mastnak ◽  
Aleksandra Lobnik ◽  
Gerhard Mohr ◽  
Matjaž Finšgar
Keyword(s):  
Biogenic Amines ◽  
Vinyl Acetate ◽  
Colour Change ◽  
Ethylene Vinyl Acetate ◽  
Yellow Orange ◽  
Colour Changes ◽  
Limit Sensitivity ◽  
Linear Concentration Range ◽  
Acetate Copolymer ◽  
Ethylene Vinyl Acetate Copolymer

The article presents naked-eye methods for fast, sensitive, and selective detection of isopentylamine and cadaverine vapours based on 4-N,N-dioctylamino-4′-dicyanovinylazobenzene (CR-528) and 4-N,N-dioctylamino-2′-nitro-4′-dicyanovinylazobenzene (CR-555) dyes immobilized in ethylene-vinyl acetate copolymer (EVA). The reaction of CR-528/EVA and CR-555/EVA indicator layers with isopentylamine vapours caused a vivid colour change from pink/purple to yellow/orange-yellow. Additionally, CR-555/EVA showed colour changes upon exposure to cadaverine. The colour changes were analysed by ultraviolet–visible (UV/VIS) molecular absorption spectroscopy for amine quantification, and the method was partially validated for the detection limit, sensitivity, and linear concentration range. The lowest detection limits were reached with CR-555/EVA indicator layers (0.41 ppm for isopentylamine and 1.80 ppm for cadaverine). The indicator layers based on EVA and dicyanovinyl azobenzene dyes complement the existing library of colorimetric probes for the detection of biogenic amines and show great potential for food quality control.

scholarly journals Influence of Natural and Artificial Weathering on the Colour Change of Different Wood and Wood-Based Materials

Forests ◽  
2018 ◽  
Vol 9 (8) ◽  
pp. 488 ◽  
Author(s):  
Davor Kržišnik ◽  
Boštjan Lesar ◽  
Nejc Thaler ◽  
Miha Humar
Keyword(s):  
Laboratory Test ◽  
Colour Change ◽  
Natural Weathering ◽  
Blue Staining ◽  
Artificial Weathering ◽  
Blue Stain Fungi ◽  
Colour Changes ◽  
Blue Stain ◽  
Positive Correlations ◽  
The Aesthetic

The importance of the aesthetic performance of wood is increasing and the colour is one of the most important parameters of aesthetics, hence the colour stability of twelve different wood-based materials was evaluated by several in-service and laboratory tests. The wood used for wooden façades and decking belongs to a group of severely exposed surfaces. Discolouration of wood in such applications is a long-known phenomenon, which is a result of different biotic and abiotic causes. The ongoing in-service trial started in October 2013, whilst a laboratory test mimicking seasonal exposure was performed in parallel. Samples were exposed to blue stain fungi (Aureobasidium pullulans and Dothichiza pithyophila) in a laboratory test according to the EN 152 procedure. Afterwards, the same samples were artificially weathered and re-exposed to the same blue stain fungi for the second time. The purpose of this experiment was to investigate the synergistic effect of weathering and staining. The broader aim of the study was to determine the correlation factors between artificial and natural weathering and to compare laboratory and field test data of fungal disfigurement of various bio-based materials. During the four years of exposure, the most prominent colour changes were determined on decking. Respective changes on the façade elements were significantly less prominent, being the lest evident on the south and east façade. The results showed that there are positive correlations between natural weathering and the combination of artificial weathering and blue staining. Hence, the artificial weathering of wood-based materials in the laboratory should consist of two steps, blue staining and artificial weathering, in order to simulate colour changes.

scholarly journals Microwave-induced fast decalcification of rat bone for electron microscopic analysis: an ultrastructural and cytochemical study

2007 ◽  
Vol 18 (2) ◽  
pp. 153-157 ◽  
Author(s):  
Dimitrius Leonardo Pitol ◽  
Flavio Henrique Caetano ◽  
Laurelúcia Orive Lunardi
Keyword(s):  
Osmium Tetroxide ◽  
Microscopic Analysis ◽  
Electron Microscopic Analysis ◽  
Electron Microscopic ◽  
Cytochemical Study ◽  
Domestic Microwave Oven ◽  
Total Experiment Time ◽  
Transmission Electron ◽  
Rat Bone ◽  
Potassium Pyroantimonate

Bone decalcification is a time-consuming process. It takes weeks and preservation of the tissue structure depends on the quality and velocity of the demineralization process. In the present study, a decalcification methodology was adapted using microwaving to accelerate the decalcification of rat bone for electron microscopic analysis. The ultrastructure of the bone decalcified by microwave energy was observed. Wistar rats were perfused with paraformaldehyde and maxillary segments were removed and fixed in glutaraldehyde. Half of specimens were decalcified by conventional treatment with immersion in Warshawsky solution at 4ºC during 45 days, and the other half of specimens were placed into the beaker with 20 mL of the Warshawsky solution in ice bath and thereafter submitted to irradiation in a domestic microwave oven (700 maximum power) during 20 s/350 W/±37ºC. In the first day, the specimens were irradiated 9 times and stored at 40ºC overnight. In the second day, the specimens were irradiated 20 times changing the solution and the ice after each bath. After decalcification, some specimens were postfixed in osmium tetroxide and others in osmium tetroxide and potassium pyroantimonate. The specimens were observed under transmission electron microscopy. The results showed an increase in the decalcification rate in the specimens activated by microwaving and a reduction of total experiment time from 45 days in the conventional method to 48 hours in the microwave-aided method.

scholarly journals New data on the immunohistochemical and morphological characteristics of ductal pancreatic adenocarcinoma

2018 ◽  
Vol 42 (4) ◽  
pp. 47-52
Author(s):  
Y. Y. Rakina ◽  
M. V. Zav’yalova ◽  
N. V. Krakhmal ◽  
A. P. Koshel ◽  
S. G. Afanasyev ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Pancreatic Adenocarcinoma ◽  
Malignant Tumors ◽  
Standard Procedure ◽  
Morphological Characteristics ◽  
Developed Countries ◽  
Ductal Pancreatic Adenocarcinoma ◽  
Microscopic Features ◽  
Giovanni Battista Morgagni ◽  
Immunohistochemical Studies

In recent years, especially in developed countries, there has been an increase in the incidence of pancreatic cancer. Only 20% of tumors at the time of diagnosis are evaluated as resectable, but in these cases, the prognosis of the disease is unfavorable. The overall 5-year survival rate does not exceed 5%. Pancreatic cancer was described in the 1760s by Giovanni Battista Morgagni in his classic book “De Sedibus et Causis Morborum per Anatomen Indigatis”. Over the next 200 years, pathologists significantly improved our understanding of the macro- and microscopic features of this disease. At the same time, morphological research remained the basis of diagnostics for centuries. The introduction of immunohistochemical studies into clinical practice in the late 1970s and early 1980s radically changed our approach to diagnosing this disease. Evaluation of morphological features, as well as features of expression of markers that determine the invasive potential of such neoplasms, can serve in the future as a fundamental basis in solving questions concerning possible factors of prognosis upon malignant tumors of such a localization. Aim of research — to study the morphological and immunohistochemical features of ductal pancreatic adenocarcinoma. Materials and methods. The study included 84 patients with pancreatic cancer T1-4N0-2M0-1 stage, aged from 37 to 83, who underwent surgical treatment. Morphological study of the operating material was carried out. The condition for inclusion in the study was a histotype of the tumor, namely ductal pancreatic adenocarcinoma. Posting of the material, preparation of histological preparations, coloring, immunohistochemical examination were carried out according to a standard procedure. Results and conclusion. The study made it possible to characterize the tumor morphology, as well as the features of expression of markers associated with more evident invasive characteristics of the tumor. The results of this work may be of interest in terms of their further comparison with the parameters of various forms of progression upon pancreatic cancer.

Formation of Green Pigment and Colour Changes in Orthoptera

1953 ◽  
Vol 44 (2) ◽  
pp. 299-315 ◽  
Author(s):  
Salâhattin Okay
Keyword(s):  
Fat Body ◽  
Colour Change ◽  
Blue Pigment ◽  
Breakdown Product ◽  
Bile Pigment ◽  
Green Pigment ◽  
Yellow Colour ◽  
Blue Component ◽  
Colour Changes ◽  
Background Reaction

The colour change and formation of green pigment in Mantis, Acrida, Locusta, Schistocerca and Dixippus are studied.There is no background reaction to green and brown or yellow colour in these species.Usually the young nymphs of Mantis are green; some ofthe old nymphs and adults have a tendency to lose the green pigment. Phytophagous nymphsbecome green only when fed on fresh or growing grass. Green individuals may be obtained in darkness on this food (Locusta). The green pigmentdisappears on a diet of dry grass.The colour change from non-green to green, or vice versa, is dependent on the formation or disappearance of the blue component (bile pigment-protein) of green pigment. The blue pigment generally appears first in the blood and is deposited in the integument at the following moult; it does not appear to be a breakdown product of chlorophyll or haematin. It is probably synthesised from a colourless precursor in the peripheral fat body.Observations made on the pericardial cells of Locusta suggest that the blue pigment may be converted into insectorubin.

CLINICAL AND MORPHOLOGICAL CHARACTERISTICS OF CHRONIC RECURRENT HEMATOGENOUS OSTEOMYELITIS

2020 ◽  
Vol 93 (1) ◽  
pp. 93-99
Author(s):  
Azamat Shamsiev ◽  
◽  
Sukhrob Zainiev ◽  
N. Alieva
Keyword(s):  
Electron Microscopy ◽  
Microbial Contamination ◽  
Morphological Characteristics ◽  
Medullary Canal ◽  
Pathological Changes ◽  
Morphological Studies ◽  
Hematogenous Osteomyelitis ◽  
Transmission Electron ◽  
Bone Fragments ◽  
Tubular Bones

The studied material of scanning and transmission electron microscopy were bone fragments of 40 patients obtained during surgery from various pathologically altered sections of the affected tubular bones. Morphological studies revealed microscopic foci of necrosis, leukocyte infiltrates and microabscesses both in the main focus and in other parts of the bone marrow canal. Microabscesses detected by microscopy represent the morphological basis of chronic hematogenous osteomyelitis, can be located at a considerable distance from the main necrotic purulent focus and, under appropriate conditions, cause a relapse of the disease. Morphological studies have shown that surgical debridement of the lesion with ultrasonic cavitation of the lesion and the medullary canal contributes to a significant reduction in the degree of microbial contamination, followed by a decrease in pathological changes in bone tissue.

scholarly journals Regeneration of experimental long bone defect after implantation in its cavity of osteoplastic material “Calc-i-oss®”

2016 ◽  
Vol 33 (02) ◽  
pp. 099-102
Author(s):  
O. Korenkov
Keyword(s):  
Bone Tissue ◽  
Morphological Characteristics ◽  
Compact Bone ◽  
Long Bone ◽  
Electron Microscopic ◽  
Time In Literature ◽  
Microscopic Features ◽  
Definition Of ◽  
Osteoplastic Material ◽  
Long Bone Defect

Abstract Introduction: There is a significant divergence of data on the rate of resorption and replacement by the bone tissue of osteoplastic materials based on β-tricalcium phosphate in cancellous bone. At the same time in literature missing morphometric and electron microscopic features of bone tissue of the regenerate of compact substance of bone in these conditions. This study was aimed at the assessment of the healing of compact bone tissue defect after implantation of osteoplastic material “Calc-i-oss®” with the definition of the dynamics of resorption and morphological characteristics of bone tissue of the regenerate. Material and Methods: In the middle third of the diaphysis of the femur of rats there was reproduced the perforated defect to the bone-brain channel that was filled with osteoplastic material “Calc-i-oss®”. After surgery the fragments of injured bones were studied at the 60th and 120th day by methods of light microscopy with morphometry and scanning electron microscopy. Results: The conducted research revealed no inflammatory reaction at the site of the defect, signs of necrobiosis and necrosis of osteocytes in adjacent to the site of implantation maternal bone. The site of defect was filled with lamellar bone tissue high in osteoblasts, osteocytes and with integrated into its structure remains of “Calc-i-oss®”. On the surface and inside the implant there were found osteogenic cells and bone foci. It was established that the osteoplastic material throughout the observation period is subjected to development and replacement by bone tissue of the regenerate, the ratio of which on the 60th day of the experiment was 25.72 ± 2.06% to 74.28 ± 2.06%, and on the 120th day - 18.31 ± 1.54% to 81.69 ± 1.54%. Conclusion: Osteoplastic material “Calc-i-oss®” exhibits biocompatibility, osteoconductive properties, ability to resorption and is replaced by bone tissue, with which it integrates well.

scholarly journals Bioinspired Synthesis of Acacia senegal Leaf Extract Functionalized Silver Nanoparticles and Its Antimicrobial Evaluation

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Edwina Olohirere Uzunuigbe ◽  
Abidemi Paul Kappo ◽  
Sixberth Mlowe ◽  
Neerish Revaprasadu
Keyword(s):  
Silver Nanoparticles ◽  
Colour Change ◽  
Silver Ions ◽  
Antibacterial Activities ◽  
Cubic Phase ◽  
X Ray Diffraction ◽  
Leaf Extracts ◽  
Acacia Senegal ◽  
Transmission Electron ◽  
Antimicrobial Evaluation

Synthesizing nanoparticles with the less environmentally malignant approach using plant extract is of great interest; this is because most of the chemical approaches can be very costly, toxic, and time-consuming. Herein, we report the use of Acacia senegal leaf extracts to synthesize silver nanoparticles (AgNPs) using an environmentally greener approach. Silver ions were reduced using the bioactive components of the plant extracts with observable colour change from faint colourless to a brownish solution as indication of AgNP formation. The structural properties of the as-synthesized AgNPs were characterized using powder X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), and UV-Vis absorption spectrum. Antimicrobial assessment of the as-synthesized AgNPs was explored on some strains of gram-positive and gram-negative bacteria. The obtained results indicate that the as-synthesized AgNPs are pure crystallite of cubic phase of AgNPs, fairly dispersed with a size range of 10–19 nm. The AgNPs were found to be small in size and exhibit significant antibacterial activities, suggesting that the as-synthesized AgNPs could be used in the pharmaceutical and food industries as bactericidal agents.

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