amorphous substance
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Author(s):  
М. Ш. Саламанова

В работе исследовано влияние микрокремнезема на кинетику набора прочности, изменение плотности и порового пространства цементного камня, рецептурно-технологических факторов и условий твердения. Обоснованы химические превращения микрокремнезема в условиях щелочной среды, приводящие к изменениям водородного показателя. Структура цементного камня характеризуется присутствием гидроалюмосиликатов натрия и кальция, кристаллических новообразований, близких к ларниту, и их гидратов, аморфной субстанции, сульфоалюминатов кальция, гидроалюминатов кальция. The paper investigates the effect of microsilica on the kinetics of strength gain, changes in the density and pore space of cement stone, formulation and technological factors and hardening conditions. The chemical transformations of silica fume under alkaline conditions, leading to changes in the pH value, have been substantiated. The structure of the cement stone is characterized by the presence of sodium and calcium hydroaluminosilicates, crystalline neoplasms similar to larnite and their hydrates, amorphous substance, calcium sulfoaluminates, calcium hydroaluminates.


Molecules ◽  
2020 ◽  
Vol 25 (22) ◽  
pp. 5437
Author(s):  
Roman P. Terekhov ◽  
Irina A. Selivanova ◽  
Nonna A. Tyukavkina ◽  
Igor R. Ilyasov ◽  
Anastasiya K. Zhevlakova ◽  
...  

A large amount of the current literature dedicated to solid states of active pharmaceutical ingredients (APIs) pays special attention to polymorphism of flavonoids. Taxifolin (also known as dihydroquercetin) is an example of a typical flavonoid. Some new forms of taxifolin have been reported previously, however it is still unclear whether they represent polymorphic modifications. In this paper, we tried to answer the question about the taxifolin polymorphism. Taxifolin microtubes and taxifolin microspheres were synthesized from raw taxifolin API using several methods of crystal engineering. All forms were described with the help of spectral methods, scanning electron microscopy (SEM), X-ray powder diffraction (XRPD), and thermal analysis (TA). SEM reveals that the morphology of the solid phase is very specific for each sample. Although XRPD patterns of raw taxifolin and microtubes look similar, their TA profiles differ significantly. At the same time, raw taxifolin and microspheres have nearly identical thermograms, while XRPD shows that the former is a crystalline and the latter is an amorphous substance. Only the use of complex analyses allowed us to put the puzzle together and to confirm the polymorphism of taxifolin. This article demonstrates that taxifolin microtubes are a pseudopolymorphic modification of raw taxifolin.


Diversity ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 102 ◽  
Author(s):  
Anastasia Rizouli ◽  
Frithjof C. Küpper ◽  
Paraskevi Louizidou ◽  
Andrew O. M. Mogg ◽  
Elaine Azzopardi ◽  
...  

Substratum collected during diving surveys of sublittoral communities off the Greek island of Rhodes (Dodecanese, South-East Aegean) in late 2015 was incubated in the laboratory. Among the emerging macroalgal germlings, there was the second-ever record and isolate of the small benthic multicellular alga Schizocladia ischiensis of the poorly known monotypic Schizocladiophyceae, the sister group of the brown algae (Phaeophyceae). Its nuclear ribosomal small subunit, Rubisco spacer (rbcL, psaA, and psbC sequences (in total 5237 bp)) were similar to those of the only previous isolate of the species from Ischia, western Mediterranean. Our new strain formed branched upright thalli attached to the substratum by an amorphous substance secreted at the bottom of the basal cell. It is possible that S. ischiensis is a common member of the infralittoral and circalittoral communities in the Mediterranean and generally overlooked because of its minute size. Germling emergence appears to represent the method of choice to reveal benthic algae of this small size.


2019 ◽  
Vol 485 (6) ◽  
pp. 682-685
Author(s):  
D. S. Sanditov

In this communication, a condition based on the deactivation of the trigger mechanism of creep is proposed for the liquid-glass transition of an amorphous substance. This mechanism is confined to the atom delocalization process, which in silicate glasses represents the ultimate displacement of the bridging oxygen atom in the Si-O-Si bridge due to the local low-activation elastic strain of the silicon-oxygen network.


Author(s):  
D. A. Petrochenkov

For the first time, the mineral composition and gemological characteristics of the petrified wood from the Ulyanovsk region, of jewelry and ornamental quality, have been studied. The petrified wood is associated with the Lower Cretaceous deposits and consists mainly of calcite (up to 73 mass. %); pyrite, apatite, gypsum are present; dolomite, anhydrite, hematite, pyrolusite, organic matter and X-ray amorphous substance have been fixed. According to the technological and decorative characteristics, the petrified wood of the Ulyanovsk region is a quality jewelry and ornamental material of the florogenic group.


2018 ◽  
Vol 24 (2) ◽  
pp. 50-56
Author(s):  
О.Ye. Маievskyi ◽  
К.S. Volkov ◽  
Z.M. Nebesna ◽  
Ye.V. Mironov ◽  
A.V. Shayuk

For pathogenetically grounded therapy of burn disease, aimed at reducing the severity of the pathological process, the rapid recovery of microcirculation and stimulation of reparative processes, it is necessary to study the fine mechanisms of reparative regeneration in the skin on the microscopic and biochemical levels. The purpose of the study is to investigate the state of elastic and collagen fibers, as well as glycoproteins and glycosaminoglycans in the intercellular substance of the dermis of rats 1, 3, 7, 14, 21 and 30 days after the burning of the II-III degree, with the background of the injection during first 7 days of 0.9% NaCl solution. An experimental study of structural changes in the skin after burn injury was performed on laboratory white rats, males weighing 150-160 g. Rats were divided into 2 groups, which previously, under the conditions of propofol anesthesia 60 mg/kg internally, catheterization of the femoral vein and depilation lateral surfaces of the trunk of rats. Group 1 - animals without thermal trauma of the skin, which once a day for the first 7 days were injected intravenous infusion of 0.9% NaCl solution in a dose of 10 ml per kg. Group 2 - animals who were also injected once a day with the first 7 days of infusion of 0.9% NaCl solution in a dose of 10 ml per kg after 2-3 degree skin burns, with a total area of 21-23% of the body surface of the rat. Euthanasia of rats was performed after propofol anesthesia (60 mg/kg i/v) by decapitation. Changes in the histochemical structure of bits of skin from the edge of the wound were studied after 1, 3, 7, 14, 21, and 30 days from the beginning of the experiment. Histological sections 5-6 microns thick were stained with Weigert’s elastic stain and dyed with picric acid by Van Gieson’s method (for the detection of elastic and collagen fibers); the PAS + Hale reaction was performed by the Moury method (detection of glycoproteins and glycosaminoglycans in the intercellular substance of the dermis). The histochemical investigations of the area of the II-III degree of skin damaged by burns on the background of the injection of 0.9% NaCl solution found that the degree of change depends on the duration of the experiment. In the early stages of the experiment, the reorganization of the intercellular substance of the dermis manifests itself as damage to the fibrous structures of its papillary and reticular layers. Histochemically, the components of amorphous connective tissue substance are dominated by glycoproteins, the content of acidic glycosaminoglycans is small. In the late stages of the experiment (after 14, 21 and 30 days) in the connective tissue of the affected skin in the central and marginal regions poorly structured collagen and elastic fibers are observed. The pronounced “Hale”-positive coloration reflects an increase in the content of sulfated glycosaminoglycans in the amorphous substance of the connective tissue. Thus, the experimental thermal trauma of skin II-III degree on the background of the introduction during the first 7 days, 0.9% of the NaCl solution is histochemically characterized by reorganization of the intercellular substance of the connective tissue of the dermis. In the early stages of the experiment there is damage to the fibrous structures of the papillary and reticular layers, the prevalence of glycoproteins and the insignificant content of acidic glycosaminoglycans in the amorphous substance, indicating a significant inhibition of adaptive-compensatory processes. In the long term, after the thermal defeat in the dermis, histochemically, an increase in the amount of acid glycosaminoglycans is detected and the PAS positivity of the collagen fibers of the intercellular substance is well expressed. This indicates a slow updating of the amorphous substance and fibrous structures of the connective tissue of the dermis, a violation of regenerative processes.


2016 ◽  
Vol 6 (2) ◽  
pp. 31
Author(s):  
José Lucas Soares Ferreira ◽  
Ingrid Carneiro Cavalcante Souto ◽  
Emanuelle Ferreira Alves ◽  
Heloísa Mara Batista Fernandes de Oliveira ◽  
Maria Angélica Satyro Gomes Alves ◽  
...  

O presente estudo objetiva realizar uma revisão critica da literatura sobre sialólitos do ponto de vista de desenvolvimento, etiologia, sintomatologia, diagnóstico e tratamento. Os sialólitos são calcificações que obstruem o interior das glândulas salivares ou o interior de seus ductos, compostos por um núcleo de substância amorfa envolto de íons provenientes da saliva. A sialolitíase é a doença mais comum das glândulas salivares, possui uma predileção por homens de meia idade. Os sialólitos são mais relatados nas glândulas submandibulares por suas características anatômicas e pelas características da saliva excretada. Sabe-se muito pouco sobre a etiologia real da doença, porém são elencados como predisponentes a anatomia da glândula e seu ducto e a composição da saliva excretada. Os métodos de diagnósticos mais utilizados são a radiografia oclusal e panorâmica, mas atualmente os exames imaginológicos como a tomografia computadorizada, ressonância magnética e ultra-som vêm ganhando espaço na odontologia. Os métodos de tratamento variam conforme os aspectos cínicos do caso variando de métodos conservadores como a ordenha e manipulação da glândula até tratamentos mais invasivos como acessos cirúrgicos intra ou extra-orais.Salivary glands stones: a critical review of the literatureAbstract: This study aims to conduct a critical review of the literature on sialolith the viewpoint of development, etiology, symptoms, diagnosis and treatment. The sialolith calcifications are obstructing the interior of the salivary glands or within their ducts, comprising a core of amorphous substance wrapped ions from saliva. The sialolithiasis is the most common disease of the salivary glands, has a predilection for middle-aged men. The sialoliths are more reported in the submandibular glands by their anatomical characteristics and the characteristics of excreted saliva. We know very little about the actual etiology of the disease, but are listed as predisposing the anatomy of the gland and its duct and the composition of the secreted saliva. The methods most commonly used diagnostics are the occlusal and panoramic x-ray, but currently the imaging tests such as computed tomography, magnetic resonance and ultrasound are gaining space in dentistry. Treatment methods vary cynics aspects case ranging from conservative methods such as the milking and handling of the gland to more invasive treatments such as intra- or extra-oral surgical approaches.


2016 ◽  
Vol 9 ◽  
pp. MBI.S33394 ◽  
Author(s):  
Sudipta Roy ◽  
Sahana Yasmin ◽  
Subhadeep Ghosh ◽  
Somesankar Bhattacharya ◽  
Debdulal Banerjee

This study was conducted to isolate endophytic bacteria possessing anti-infective property from Kalmegh ( Andrographis paniculata Nees.), a well-known medicinal plant. A total of 23 strains were isolated from this plant among which the strain KL1, isolated from surface-sterilized leaf of this medicinal herb, showed broad-spectrum antagonism against an array of Gram-positive and -negative bacterial pathogens. Ethyl acetate extract of KL1-fermented media yielded a greenish amorphous substance retaining anti-infective property. Solvent-extracted crude material was separated by thin-layer chromatography, and the active ingredient was located by autobiogram analysis. The purified anti-infective compound was found as anthracene derivative as analyzed by ultraviolet and Fourier transform infrared spectroscopy. The strain was identified as Bacillus thuringiensis KL1 from cultural, physiochemical, and molecular aspects. The above results indicate the pharmaceutical potential of the candidate isolate.


2015 ◽  
Vol 40 (1) ◽  
pp. 3-19 ◽  
Author(s):  
M. Podbielkowska

The nucleolus structure in the cells of numerous <i>Angiospermae</i> plants was studied with light microscope. The living material was examined under phase and anoptral contrast. Microscopical observations were also carried out on the material fixed in chrome-formalin or in uranyl-formalin. An occurrence of two structural components of nucleolus was demonstrated: an amorphous ground substance and nucleolonema. Cytochemical analysis have shown that considerable amounts of RNA and acid proteins were located in the amorphous substance while nucleolonema was composed of basic proteins and slight quantities of RNA.


2011 ◽  
Vol 287-290 ◽  
pp. 1189-1192
Author(s):  
Bo Wang ◽  
Yuan Ming Song

There is much difference among the amorphous substances of different coal ashes, the important basis for their utilization. The micromorphology and content of the amorphous substances were measured by scanning electron microscopy (SEM) and chemical method respectively, and the 28d compressive strength ratio was also used to characterize their contribution to the cement-coal ashes system. The results show that the amorphous substances of BFBC/CFBC ashes are irregular and loose textured, which are significantly different from those of PC fly ashes that are spherical and compact. The content and the pozzolanic activity of the amorphous substance of BFBC ashes are greater than that of PC fly ashes.


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