Features Of Micro Research Articles

Space‐ and Time‐resolved Emission Features of Micro‐ and Nano‐sized Perylene‐based Zr Metal‐Organic Frameworks

AbstractWhile many photoresponsive metal‒organic frameworks (MOFs) have been reported to date, finding applications in several technologically relevant fields such as photocatalysis, sensors, and light‐emitting devices, significantly scarcer are the reports addressing the relationship between the MOFs emissive features and their crystalline domain size (i.e., micro‐ and nano‐sized materials). Herein, a valuable contribution is offered to this issue which consists of the use of reticular chemistry to prepare a Zr‐MOF featuring spatially separated tetracarboxylated‐functionalized perylenes as ligand. Single crystal X‐ray analysis of such Zr‐MOF revealed the formation of micro‐ and meso‐porous channels. The perylene‐based Zr‐MOF exhibited notable optoelectronic features, including a relatively small optical bandgap of 1.82 eV and emission features different from that of the constituting perylene ligand in the solid state. Additionally, local probe techniques are used to unveil the emission properties of isolated Zr‐MOF crystals. Space‐ and time‐resolved fluorescence studies revealed a strong dependence of the emissive features of the Zr‐MOF, both in terms of its intensity and lifetime, to the crystalline domain size.

Microfabrics impact on rock salt geomechanical diversity – an experimental investigation

Geomechanical studies of rock salt serve as the foundation for designing and ensuring the long-term stability of storage caverns. Research conducted in recent years has shown that rock salt exhibit highly variable mechanical parameters. Even macroscopically similar rock salt samples from the same formation have very different mechanical parameters in standard strength tests. In this paper, the effect of microfabrics on the mechanical behaviour of rock salt was studied using a uniaxial compression device with simultaneous observation under a microscope. The tests were carried out on rock salt samples, previously tested on standard uniaxial compression (UCS). Tested samples showed different strength values despite macroscopic similarity and similar anhydrite content. The tests revealed that the microfabrics, such as fluid inclusions and anhydrite crystals distributed along the halite grain boundaries, play a significant role in the strength of a rock salt sample. Four types of grain boundaries were recognized in both group of samples: (1) dominated by anhydrite crystals with a small number of fluid inclusions (FIs), (2) with FIs prevailing over anhydrite crystals, (3) only with FIs, and (4) without anhydrite crystals or FIs. The experimental uniaxial compression tests in microscale (mUCS) showed that the damage process is initiated by FIs activity at the halite grain boundaries and consists of three main stages. The samples dominated by anhydrite crystals at halite grain boundaries were characterised by the highest mUCS. Conversely, if FIs prevail at the grain boundaries the lowest mUCS values were registered. Therefore, anhydrite crystals located along halite grain boundaries influenced the mechanical behaviour and deformation process. On the contrary, anhydrite crystals dispersed within halite grains had no impact on failure and mechanical parameters. The experiment showed that apart from impurity content, the distribution of these impurities within halite grains should be examined during geomechanical evaluation of rock salt samples. Thus, the overall strength of rock salt samples determined in standard test results from the local variations of petrological features in micro- and macro scale.

The efficacy of clinicopathological and imaging features in differentiating benign from malignant parotid micro- and minitumors: a retrospective analysis

ObjectiveTo compare clinicopathological and imaging and features of micro- and minitumors of the parotid gland and provide a reference for preoperative prediction of benign vs. malignant status. Study DesignPatients with parotid gland tumors treated surgically were selected. Relevant clinicopathological and imaging data were collected for patients with maximum tumor diameters ≤ 20 mm on preoperative computed tomography (CT). The lesions were divided into two groups, microtumors and minitumors, based on maximum tumor diameter. CT imaging features of benign and malignant tumors were compared through binary logistic regression analysis. ResultsMicrotumors and minitumors were categorized by maximum diameters < 10 mm (n = 74) and 10-20 mm (n = 611), respectively. Benign and malignant minitumors exhibited significant differences in boundary, tumor density, margin morphology, spiculation margin, and CT values in the plain and arterial phase (P < 0.05), resembling those found in typical malignant parotid gland tumors. However, no significant differences were observed between benign and malignant microtumors. Logistic regression analysis identified boundary, margin morphology, and spiculation margin as independent predictors of malignancy. The prediction model excelled in identifying benign lesions but was less successful in identifying malignancies. ConclusionParotid gland minitumors had imaging features similar to typical larger malignant tumors. Active exclusion of the malignant risk and early surgical treatment is recommended for these tumors. Statement of Clinical RelevanceThis study analyzed the clinicopathological and imaging features of micro- and minitumors of the parotid gland to provide a reference for preoperative prediction and treatment. Active exclusion of malignant risk and early surgical treatment is recommended for small parotid tumors.

Review of Micro- and Nanobubble Technologies: Advancements in Theory and Applications and Perspectives on Adsorption Cooling and Desalination Systems

Adsorption refrigerators are a compelling ecological alternative to compressor refrigerators; global warming forces us to constantly look for alternative sources of energy and cold. Cold production in adsorption chillers is based on the use of heat generated by other processes running in the company. Waste heat from production processes, which has, until now, been irretrievably lost, is a potential source of energy for generating cold via an adsorption unit producing chilled water. Cooling optimizes the use of the heating network in summer and can lead to increased electricity production while reducing heat supply losses. Thus far, attempts to implement adsorption refrigerators for widespread use have not been successful as a result of the low efficiency of these devices; this is directly related to the poor heat and mass transfer conditions in the beds and heat exchangers of adsorption refrigerators. The solutions used so far, such as new working pairs, glued beds or modifications to the structure or cycle length, are still not strong enough for these devices. Therefore, it is necessary to look for new solutions. Using micro- and nanobubbles as media to increase mass and heat transfer in refrigerators is an innovative and pioneering solution. Thus, this document describes the most important features of micro- and nanobubble technology applications in adsorption refrigerators. This article is an introduction and a basis for the implementation of further research, consolidating the existing literature as a review.

Correlative Fluorescent Scanning Probe Nanotomography Used to Study the Intracellular Distribution of Doxorubicin in MCF-7 Human Breast Adenocarcinoma Cells

Developing technologies for efficient targeted drug delivery for oncotherapy requires new methods to analyze the features of micro- and nanoscale distributions of antitumor drugs in cells and tissues. A new approach to three-dimensional analysis of the intracellular distribution of cytostatics was developed using fluorescence scanning optical-probe nanotomography. A correlative analysis of the nanostructure and distribution of injected doxorubicin in MCF-7 human breast adenocarcinoma cells revealed the features of drug penetration and accumulation in the cell. The technology is based on the principles of scanning optical probe nanotomography and is applicable to studying the distribution patterns of various fluorescent or fluorescence-labelled substances in cells and tissues.

INVESTIGATION OF THE INTRACELLULAR DISTRIBUTION OF DOXORUBICIN IN MCF-7 HUMAN BREAST ADENOCARCINOMA CELLS BY THE METHOD OF CORRELATIVE SCANNING FLUORESCENT PROBE NANOTOMOGRAPHY

The development of technologies for effective targeted drug delivery for oncotherapy requires the elaboration of new methods to analyze the features of micro- and nanoscale distributions of antitumor drugs in cells and tissues. This paper presents a new approach to three-dimensional analysis of intracellular distribution of cytostatics using fluorescence scanning optical-probe nanotomography technology. Correlative analysis of nanostructure and distribution of injected doxorubicin in studied MCF-7 human breast adenocarcinoma cells made it possible to reveal the features of drug penetration and accumulation in cells. The developed technology based on the principles of scanning optical probe nanotomography is applicable to study the distribution patterns of various fluorescent or fluorescence-labelled substances in cells and tissues.

Micro and nanobubbles technologies as a new horizon for CO2-EOR and CO2 geological storage techniques: A review

CO2 capture, utilization, and storage technology are one of the most effective methods to reduce CO2. Although this technology has been relatively mature, the main problems limiting the large-scale application are the security of geological storage. The advantage of micro and nanobubbles is widely acknowledged due to their size and stability. Micro and nanobubbles are tiny gas-liquid dispersion systems with unique physical characteristics. The important features of micro and nanobubbles include their excellent stability, high internal pressure, extremely large surface-to-volume ratio, and high gas dissolution rate, which lead to promising applications in various fields. This review discussed the studies conducted in the areas of micro and nanobubbles with a special emphasis on CO2-EOR and CO2 geological storage. The micro and nanobubbles classifications and their composition were briefly introduced. The preparation methods of micro and nanobubbles and the main factors affecting their properties were investigated in detail. The characterization parameters with state- of – the art measuring and analysis techniques of microbubble and nanobubble technologies were summarized. Furthermore, the major applications in CO2-EOR and CO2 geological storage were discussed. Base on this review, various potential areas,and gaps for MNB research in CO2– EOR and CO2 geological storage fields are identified for further investigations.

Removal Methods of Plastic Waste and Interactions of Micro- and Nano-Plastics with Plants

The presence of plastic waste in large quantities in the environment is a major problem and therefore a challenge for many researchers to examine the most effective methods of their disposal. In this paper, the source of microplastic and its hazardous effect on human health and interactions of plastics with plants were studied. Due to the specific physical-chemical features of micro- and nano-plastics, they are ideal candidates for the adsorption of organic pollutants, pathogens and heavy metals. The uptake and accumulation of nanoplastics by plants, adsorption studies, and bioaccumulation are shown here. In addition, recent research on the interaction of polystyrene micro- and nanoplastics with plants has been discussed. Many studies have shown that the most affected part of the plant was the roots, followed by leaves, shoots, and then the stem. Nanoplastics are found to be more harmful than microplastics due to permeation through the biological membranes of plants, while microplastics adhere to leaves.

The adoption of artificial intelligence powered workforce management for effective revenue growth of micro, small, and medium scale enterprises (MSMEs)

Artificial intelligence (AI) has been used in various industries to provide innovative and intelligent features in micro, small and medium enterprises (MSMEs). Big industries started adopting AI for their HR and workforce management (WFM) activities, however, past literature suggests a lack of AI adoption in MSMEs. In the ongoing pandemic, a large number of job loss is reported in the literature. Thus, artificial intelligence-powered intelligent workforce management (WFM) may be critical during or post-pandemic to manage the huge employment in MSMEs. In this study, we develop and test a conceptual framework based on three areas where AI-powered WFM adoption for MSMEs revenue development has been highlighted. These are (a) risk management (workforce), (b) business and marketing, and (c) information exchange. Six hypotheses have been proposed and tested using structural equation modelling (SEM) with responses from 307 employees. According to the research findings, all of the offered hypotheses are significant. The findings suggest to MSME decision-makers that AI-powered WFM may help revenue growth, workforce risk reduction, intelligent business and marketing, and thoughtful, innovative, and safe information exchange. MSMEs are required to use AI in the information sharing that help in workforce risk management, business and marketing, and intelligent workforce management that scale-up the economic growth.

Digital emotion analytics: a pilot study of human emotion recognition using mobile device sensors

Affective computing is a rapidly developing area at the intersection of psychology and the development of artificial intelligence systems. At the moment, systems for recognising human emotions from photos and videos (facial expressions), voice recordings (intonation), gestures, posture, gait and other data using various machine learning algorithms are actively developed. This research project is devoted to the recognition of emotions and mental states of a person through the sensors of mobile devices (accelerometer, gyroscope, etc.), which record the features of micro- and macro-hand motor skills characteristic of the states under study. The pilot study considered the possibility of fixing and differentiating psychoemotional states according to the readings of sensors of mobile devices (tablet, smartphone), using machine learning models. As a result, it was possible to obtain models that determine, according to the readings of the sensors of a mobile device in the hands of a person, whether it is in a neutral emotional state or under stress. Moreover, it was possible to differentiate the state of stress according to two modalities – stress caused by psychological reasons ("fulfillment of obligations") and psychophysiological reasons (unpleasant noise in the headphones). The statistically significant differences, as well as the relatively high accuracy of the constructed machine learning model, allow us to speak about the reliability of the results obtained, and they confirm the hypothesis about the possibility of identifying and classifying emotional states using the sensors of mobile devices.

Morphological features of micro- and nanoporous silver and copper films synthesized by the substitution reaction method

The results of a study of the structural features of thin silver and copper films synthesized by the chemical substitution reaction are presented. Silver films were obtained by immersing copper substrates in a solution of silver nitrate. Copper films were synthesized by immersing iron and tin-plated iron substrates in a copper sulfate solution. The study of the morphology and composition of the synthesized layers was carried out using a scanning electron microscope. It has been shown that metal nanoporous layers up to 1 μm thick are formed on the substrates as early as 2-3 s after the start of the reaction. The layers consist of microcrystalline hexagonal plates and micro- and nanodendrites. As the reaction time increases, the layers become denser. In this case, the minimum pore size is 20 nm. The synthesized nanoporous films can be used for photocatalytic decomposition of water and enhancement of Raman scattering. Keywords: morphology, porous film, silver, copper, substitution reaction.

LANDSCAPE AND FOREST RECLAMATION APPROACH TO ASSESSING THE STATE OF PROTECTIVE FOREST PLANTINGS

Background. Previously, an inventory of protective forest belts was carried out, described within the boundaries of the administrative districts of the Rostov region. However, the forest-growing conditions of protective forest stands are determined by the landscape of the territory, so to assess the state of the Don-Salo-Manych interfluve, a landscape-forest-reclamation approach was used.&#x0D; Purpose. On the basis of the landscape-forest-reclamation approach, the assessment of the state of protective forest stands was carried out, as well as the study of polygons using remote sensing data.&#x0D; The novelty of research. For the first time, a landscape-catchment approach is applied to the assessment and grouping of protective forest plantations of the Dono-Salo-Manych interfluve of the Rostov region.&#x0D; Materials and methods. Studies of the inter-river polygon of agroforestry landscapes were carried out on the basis of a cameral analysis of remote cartographic data and landscape-forest-reclamation interpretation of space photo information.&#x0D; Results. There are 9 land-shaft areas with a weak and medium degree of land erosion. Test plots with model forest belts were laid out in each landscape area. The main tree species of protective forest belts is Robinia pseudoacacia (Robínia pseudoacácia), it occupies 65%. Оставшиеся 8% площади лесных полос относится к ясеневым (Fraxinus).&#x0D; Conclusion. The landscape-forest reclamation approach to assessing the state of field-protective forest stands includes studying the features of micro- and mesorelief, the structure of the soil cover and assessing the state of forest stands, consisting in agroforestry landscapes of the prevailing species: robinia false acacia, squat elm and green ash. Robinia false acacia occupies 65-70% of the total plantation area. Elm trees occupy 27% of the total area of planted forests, dominated by mature and over-mature stands. This approach makes it possible to plan measures for the arrangement of the landscape territory, based on knowledge of forest growing conditions.

X-ray Fluorescence Spectroscopy Features of Micro- and Nanoscale Copper and Nickel Particle Compositions.

The study is devoted to X-ray fluorescence spectroscopy (XRF) features of micro- and nanosized powder mixtures of copper and nickel. XRF is a high accuracy method that allows for both qualitative and quantitative analysis. However, the XRF measurement error due to the size of the studied particles is not usually taken into account, which limits the use of the method in some cases, such as analysis of Ni-Cu mixtures and coatings. In this paper, a method for obtaining copper and nickel nanoparticles was investigated, and the XRF of powder compositions was considered in detail. The initial micro- and nanoparticles of copper and nickel were studied in detail using SEM, TEM, XRD, and EDX. Based on experimental data, calibration curves for copper-nickel powder compositions of various sizes were developed. According to the results, it was experimentally established that the calibration curves constructed for nanoscale and microscale powders differ significantly. The presented approach can be expanded for other metals and particle sizes.

The informal features of micro and small enterprises and its incompatibility with the partnership law in Ethiopia

This paper aims to analyze unfitness of micro and small enterprises with the existing trade law particularly partnership rules in Ethiopia. Qualitative research methodology is utilized in order to capture and analyze accurate and in-depth insight of the fact that micro and small enterprises in Ethiopia are not compatible with the existing partnership law though partnership form of firms are suitable for small business. The available literatures related to the issue were professionally scrutinized and analyzed for the purpose of the research. The results of this research shows that micro and small enterprises in Ethiopia are formed as simply business organization which does not specify the kind of firm structure. Formation, management, liability and dissolution of micro and small enterprises deviate from the partnership requirements stipulated under the Ethiopian commercial code. Furthermore, micro and small enterprises are operating as informal sector business though the sectors‘ development strategy clearly states that they should be organized under trade law. Therefore, micro and small enterprises system should be reformed in order to make them to be compatible with the existing commercial law.

Symbiotic Properties of Sinorhizobium meliloti and Ethylene Production by Alfalfa Plants at the Early Stages of the Symbiosis Formation under Different Water Supply and Seed Treatment by Lectin

The symbiotic properties of bacteria significantly influence on the effectiveness of symbiosis and the yield capacity of plants. Therefore, it is important and relevant to study the features of micro- and macrosymbionts interactions, in particular under stressful conditions, and to find ways to improve the productivity of symbiotic systems. Aim. The investigation of the nodulation and nitrogen-fixing activities of Sinorhizobium meliloti as well as the ethylene production by alfalfa plants at the early stages of the formation of symbiotic system under conditions of both optimal and insufficient water supply and the pre-sowing treatment of seeds by lectin. Methods. Microbiological (cultivation of bacteria culture, seed inoculation), physiological (pot experiment), biochemical (nitrogenase activity and ethylene production determination). Results. It was observed a decrease of the nodulation activity of Sinorhizobium meliloti under drought as well as under lectin application, which was accompanied by an increase in the amount of produced by macrosymbiont ethylene at the early stages of the symbiosis formation. At the same time, the nitrogen fixing activity was inhibited at the insufficient water supply only. The use of lectin promoted the symbiotic apparatus functioning under optimal and insufficient water supply. After renewal of irrigation an increase of the nodule weight and nitrogen fixing activity as well as the aboveground mass of alfalfa plants were noted under lectin treatment. Conclusions. It was identified the role of ethylene as a negative regulator of the nodulation processes at pre-sowing treatment of alfalfa seeds with lectin. The formation of the effective nitrogen-fixing system capable of full recovery after drought under lectin application confirms the prospects for further research in the use of lectins to create optimal conditions for the realization of the symbiotic potential of rhizobia and to increase the symbiotic systemˊ resistance to the action of stress factors.

Features of micro- and ultrastructure of low-fat butter and its low-fat analogues

The aim of the research was to study the features of the structure of low-fat butter and butter pastes, which, in terms of composition and properties, more fully meet the requirements of a healthy diet than high-fat types of butter. The objects of research were: butter with fat content of 72.5%; butter with fat content of 55% made with the addition of skimmed milk powder; butter of the same fat content with the addition of stabilizers based on guar and xanthan gums and emulsifiers based on monoand diglycerides of fatty acids; butter pastes with fat content of 45% with similar additives used to increase the stability of the process of butter formation and improve the texture. The microstructure was studied using an MBI-6 microscope, and the ultramicrostructure was studied using a Phillips electron microscope. In the first case, the sample was prepared by crushing the sample, in the second one — by the method of ultrafast freeze-fracture and etching. Researches have shown that the use of the introduced ingredients improves the homogeneity of the structure of the studied products. Due to the ability of milk proteins and stabilizers to retain moisture, it is more evenly distributed and well retained in the fat matrix of the product, formed from crystalline and liquid fat in the form of a continuous phase, which is confirmed by a sufficient penetration depth of the fat-soluble dye. Plasma droplets in butter with fat content of 72.5% and 55% are more isolated than in butter pastes, as indicated by the greater penetration depth of the water-soluble dye. The average diameter of isolated moisture droplets in low-fat products was 3.3–5.4 μm, and the average diameter of the fat globules that form the basis of the crystalline framework was 5.4–7.4 μm, depending on the composition of the product. For butter with fat content of 72.5%, the values of these indicators were 2.8 and 4.0 μm. The results of the study indicate the presence of differences in the sizes of structural elements, but at the same time confirm the uniformity of the structure of low-fat products, allowing them to be attributed to dispersions «water-in-oil».

Influence of the wall material on the moisture sorption properties and conditions of stability of sesame oil hydrogel beads by ionic gelation

Sesame oil was encapsulated by ionic gelation using matrices of sodium alginate and nopal mucilage as wall material. Moisture sorption isotherms of three different types of hydrogels beads formed by SA-NM (1:0 w/w), SA-NM (1:1 w/w) and SA-NM (1:1.5 w/w) were performed at 25, 35 and 45 °C. Experimental isotherms were described by means of the GAB model, showing sigmoidal shape. Pore radius values of beads ranged from 0.81 to 7.59 nm, corresponding to micropores and mesopores classification. The integral thermodynamic properties were estimated to define conditions of maximum stability of the hydrogel beads. The point of maximum stability, linked to minimum integral entropy, was in the range 3.31–5.59 kg H2O/100 kg d.s. (corresponding to water activity, aW, of 0.23–0.59) in the studied temperature range. Enthalpy-entropy compensation for the beads exhibited the presence of two isokinetic temperatures; one at low moisture contents (0–5.95 kg H2O/100 kg d.s.) controlled by variations of the water entropy, and a second given by enthalpy-driven mechanisms. Overall, the results showed that the hydrogel beads exhibited features of micro- and meso-porous biomaterials. Besides, the composition of the wall material has central implications for the characteristics of the sorption process.

Accumulation Features of Micro and Macroelements in Indigenous and Alien Molluscs in Saldanha Bay, South Africa

Abstract Alien Mediterranean mussels Mytilus galloprovincialis, Pacific oysters Crassostrea gigas and indigenous Cape mussels Choromytilus meridionalis were used as sentinel biomonitors of inorganic pollutants in Saldanha Bay, South Africa. Neutron activation analysis was used to determine the concentrations of 33 macro and microelements in the soft tissues of molluscs. The Mediterranean mussels significantly demonstrated the higher accumulation ability to S, Se and Br than the Pacific oysters, whereas the Pacific oysters - to Fe, Cu, Zn and As. The Cape mussels are more sensitive to Mn and As and the Mediterranean mussels were sensitive to Zn and Se.

An extended EDAS method under four-branch fuzzy environments and its application in credit evaluation for micro and small entrepreneurs

With Chinese economic development in a new normal state, micro and small corporations have increasingly played an important role. The credit evaluation for micro and small corporations can contribute to efficient financial decisions. Traditional methods for the corporate credit evaluation rarely consider fuzzy features of micro and small entrepreneurs. Since the credit evaluation procedure for entrepreneurs consists of some alternatives and influential indicators, it can be recognized as a multi-criteria decision-making (MCDM) problem. To better express uncertainty information, a four-branch fuzzy set (FBFS) is presented to deal with the issue, which is characterized by a truth-membership function, an unknown-membership function and a falsity-membership function. In the paper, to handle the MCDM problems under four-branch fuzzy environments, the evaluation based on distance from average solution (EDAS) method is extended and utilized. These obvious improvement places include integrating an interval weight vector, determining an average solution, transforming a decision matrix and analyzing a change trend of the coefficients. To demonstrate the applicability and rationality of the proposed method in practice, an illustrative example is implemented, concerning a credit evaluation for some micro and small entrepreneurs. Its feasibility and validity are further verified by a sensitivity analysis and a comparative analysis. The results show the FBFSs and extended EDAS method can well match the reality and appropriately handle the credit evaluation problems for micro and small entrepreneurs.

Micro- and submicroscopic changes of the cerebellar cortex 21 days after modeling the burn

The cerebellum is a complexly organized multifunctional component of the brain and a target in numerous lesions, so the study of its morphofunctional state in various pathological conditions and burns does not lose its relevance. The aim of our study was to establish the features of micro- and submicroscopic changes in the structural components of the cerebellar cortex after 21 days under conditions of experimental thermal trauma. The experimental study was simulated on white laboratory male rats. Grade III burns were applied under thiopental-sodium anesthesia with copper plates heated in boiled water to a temperature of 97-100°C. The size of the affected area was 18-20% of the epilated surface of the body of rats. Histological changes were studied for 21 days from the beginning of the experiment. Semi-thin sections for light microscopy were stained with methylene blue, for electron microscopy the obtained ultra-thin sections were contrasted with uranyl acetate and lead citrate according to the Reynolds method. With the help of micro- and submicroscopic studies, significant alternative changes of both neurons of all layers of the cerebellar cortex and parts of the microcirculatory tract of the organ were revealed. Neurons are disorganized, their shape is changed, there is low functional activity, due to a decrease in the area of the chromatophilic substance. Often there are cell-free areas in the ganglion layer, there is a shift of Purkinje cells deep into the granular layer, and grain cells are pushed sharply into the higher molecular layer. Thus, 21 days after the experimental thermal injury, destructive-degenerative changes of neurons of the cerebellar cortex, paravasal edema and disorders of transendothelial metabolism were established.