Changes In Morphology Structure Research Articles

МОРФОЛОГИЧЕСКИЕ ОСОБЕННОСТИ СЛИЗИСТОЙ ОБОЛОЧКИ ПРОТЕЗНОГО ЛОЖА ПРИ ВОЗДЕЙСТВИИ БАЛЬНЕОЛОГИЧЕСКИХ ФАКТОРОВ

Subject. Removable orthopedic dentures able to have a negative effect on oral cavity homeostasis. Removable partial dentures bases directly situated on soft tissues which cover toothless alveolar part and partly hard palate. Dentures bases has a direct action on mucosa, causing abnormal changes from exudation to chronic inflammation. The work reviewed morphology structure changes of the prosthesis bed mucosa under mechanical action of removable orthopedic dentures construction. Further benchmark analysis of mucosa structure feature after low balneotheraphy with "Fateevskaya" mineral water. (well number 6, Fateevskoye village, Kirovo-Chepetsky District, Kirov region). 
 Objective ― make benchmarking study of oral mucosa structure features when exposed to balneology factors.
 Methods. For this purpose, bioptates from 45 patients of prosthetic dentistry clinic have been investigated. 40 patients using removable dentures no more than 4 years was devided 2 groups of 20 people. One of them is group recived the threatment with low balneotheraphy. 5 patients not used removable dentures. As a result 25 patients out of the total included in the clinical control group without balneology procedures. The medicines were subject to histological inspection.
 Results. Data evaluation: The findings of morphometric parameters testified about prosthetic bed mucosa changes, wich characteristic for chronic inflammatory gingival enlargement. Noted, using of mineral water improves histogenesis of oral mucosa and increases epithelization rate. 
 Conclusions. Thu, positive effects of balneology factors in violation of the morphological structure of the mucosa were established.
 Based on the results obtained the patent for an invention RU 2015 114 198 A «Treatment modality of oral mucosa traumatic lesions».

Deposition of polydopamine on the surface of Polyvinylidene Fluoride (PVDF) membrane as A UV-Shielding layer

This paper discusses about the influence of polydopamine layer in enhancing UV resistance of PVDF membrane for membrane photocatalytic reactor application. The PVDF membrane was prepared by common NIPS method using DMAc as a solvent and PEG as a pore-forming additive. The polydopamine layer was deposited on the membrane surface by the facile dip-coating method through Tris-buffered dopamine polymerization. The UV-shielding effect of PDA layer was studied by comparing the changes in pure and PDA coated membrane coating before and after UV irradiation. The studied effects are in terms of changes in chemical, morphological structure and mechanical properties which observed by means of ATR-FTIR, FESEM instrumental analysis, and tensile measurement, respectively. The IR analysis showed that after PDA coating, the membrane surface is rich of catecholamine groups which greatly contributed as free radical scavengers. The change in chemical structure was seen on pure membrane which attributed to the rearrangement of polymer chemical structure caused by UV-induced photodegradation. FESEM imaging results showed that with PDA coating the membrane surface showed minimal damage in comparison to that of non-coated PVDF membrane. These results altogether confirmed, that the PDA layer can protect the membrane surface from UV-initiated free radicals attack.

Maillard-Reacted Whey Protein Isolates and Epigallocatechin Gallate Complex Enhance the Thermal Stability of the Pickering Emulsion Delivery of Curcumin.

In this study, whey protein isolates (WPI), lactose (Lac) Maillard-reacted products, and epigallocatechin gallate (EGCG) complex were used to enhance the thermal stability of the Pickering emulsion delivery of curcumin. Atomic force microscopy combined with Fourier transform infrared spectroscopy were employed to study the morphological characteristics and structural changes of WPI-Lac/EGCG nanoparticles. Results proved that WPI-Lac and EGCG were combined by hydrogen bonding and hydrophobic interaction. The mechanism underlying WPI-Lac/EGCG-stabilized Pickering emulsion was further characterized by confocal laser scanning microscopy. The optimal binding ratio of WPI-Lac to EGCG was 1:1 (w/w) at pH 3.0. The particle size and zeta potential of the WPI-Lac/EGCG nanoparticles were about 110 nm and 27 mV, respectively. Analysis of microstructure and droplet size distribution revealed that the glycated WPI-Lac/EGCG-stabilized emulsions exhibited more uniform droplet distribution, stronger thermal stability, and higher curcumin percentage retention than WPI. These results indicate that the WPI-Lac/EGCG nanoparticles are potential stabilizers for Pickering emulsion requirements. This study provides a basis for the construction of Pickering emulsion systems while carrying pro-/hydrophobic bioactive components.

ADAPTATION PROCESSES IN BIOCOENOSES OF CONTAMINATED PLOTS OF THE SEMIPALATINSK TEST SITE

The article presents results of adaptation processes of main types of ecosystems (steppe, meadow, halophytic) and various types of disturbed ecosystems territories of the Semipalatinsk test site (STS). It was found that radiation pollution provokes change of morphological and anatomical structure of plants and leads to formation of some adaptation signs. Formation of adaptation signs of perennials and shrubs is expressed more clearly. Change of morphological and anatomical structure of plants happens more often in meadow (mesophyte) communities and at disturbed areas.

Downregulation of AKT and MDM2, Melatonin Induces Apoptosis in AGS and MGC803 Cells.

Melatonin, a neurohormone secreted by the pineal gland, has a variety of biological functions, such as circadian rhythms regulation, anti-oxidative activity, immunomodulatory effects, and anittumor, etc. At present, its antitumor effect has attracted people's attention due to its extensive tissue distribution, good tissue compatibility, and low toxic and side effects. In the gastrointestinal tract, there is high level of melatonin and many studies showed melatonin has effects of anti-gastric cancer. In this experiment, human gastric cancer cell lines AGS and MGC803 were used to investigate the intracellular molecular mechanism of melatonin against gastric cancer. After AGS and MGC803 have been treated with melatonin, the changes of cell morphology and cellular structure were observed under electron microscope. Flow cytometer and apoptosis detection kits were used to analyze the effect of apoptosis on AGS and MGC803. The alterations of apoptosis-related proteins Caspase 9, Caspase 3, and upstream regulators AKT, MDM2 including expression, phosphorylation, and activation were detected to analyze the intracellular molecular mechanism of melatonin inhibiting gastric cancer. In AGS and MGC803 cells with melatonin exposure, cleaved Caspase 9 was upregulated and Caspase 3 was activated; moreover, MDM2 and AKT expression and phosphorylation were downregulated. Melatonin promoted apoptosis of AGS and MGC803 cells by the downregulation of AKT and MDM2. Anat Rec, 302:1544-1551, 2019. © 2019 American Association for Anatomy.

A Screen for Synaptic Growth Mutants Reveals Mechanisms That Stabilize Synaptic Strength.

Synapses grow, prune, and remodel throughout development, experience, and disease. This structural plasticity can destabilize information transfer in the nervous system. However, neural activity remains stable throughout life, implying that adaptive countermeasures exist that maintain neurotransmission within proper physiological ranges. Aberrant synaptic structure and function have been associated with a variety of neural diseases, including Fragile X syndrome, autism, and intellectual disability. We have screened 300 mutants in Drosophila larvae of both sexes for defects in synaptic growth at the neuromuscular junction, identifying 12 mutants with severe reductions or enhancements in synaptic growth. Remarkably, electrophysiological recordings revealed that synaptic strength was unchanged in all but one of these mutants compared with WT. We used a combination of genetic, anatomical, and electrophysiological analyses to illuminate three mechanisms that stabilize synaptic strength despite major disparities in synaptic growth. These include compensatory changes in (1) postsynaptic neurotransmitter receptor abundance, (2) presynaptic morphology, and (3) active zone structure. Together, this characterization identifies new mutants with defects in synaptic growth and the adaptive strategies used by synapses to homeostatically stabilize neurotransmission in response.SIGNIFICANCE STATEMENT This study reveals compensatory mechanisms used by synapses to ensure stable functionality during severe alterations in synaptic growth using the neuromuscular junction of Drosophila melanogaster as a model system. Through a forward genetic screen, we identify mutants that exhibit dramatic undergrown or overgrown synapses yet express stable levels of synaptic strength, with three specific compensatory mechanisms discovered. Thus, this study reveals novel insights into the adaptive strategies that constrain neurotransmission within narrow physiological ranges while allowing considerable flexibility in overall synapse number. More broadly, these findings provide insights into how stable synaptic function may be maintained in the nervous system during periods of intensive synaptic growth, pruning, and remodeling.

Alkaline deep eutectic solvent: a novel green solvent for lignocellulose pulping

This work studied the feasibility of potassium carbonate-glycerol deep eutectic solvent (K2CO3-Gly DES) as a potential green solvent applied in lignocellulose pulping. Cellulose fibers were extracted from rice straw via novel alkaline DES pulping technique using 1:7 molar ratio of K2CO3-Gly DES. Optimum pulping parameters were determined using the one-factor-at-a-time (OFAT) method. The cellulose fibers were characterized for chemical composition of cellulose, hemicellulose, lignin and extractives. Changes in physical structure, chemical structure, morphological structure, functional groups and crystallinity index (CrI) were investigated using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results revealed that the optimum pulping temperature at 140 °C, reaction time of 100 min and 1:10 rice straw to DES mass ratio produced the highest cellulose content of 73.8% for unbleached DES treated pulp. Chemical composition analysis and FTIR verified that this alkaline DES pulping method was able to achieve partial removal of hemicellulose and lignin from lignocellulosic matrix. Moreover, XRD result demonstrated that the CrI of cellulose fiber increased from 52.8 to 60.0% after pretreatment. The cellulose fibers had diameters ranging from 3.58 to 5.68 µm. This study proved that the specifically-designed K2CO3-Gly DES could successfully isolate cellulose from lignocellulosic biomass through alkaline DES pulping.

Morphology and Ventilation of the Olfactory Organ in the Indo-Pacific Sergeant Abudefdufvaigiensis (Pomacentridae)

The structure of the olfactory organ in Indo-Pacific sergeant Abudefduf vaigiensis has been studied by electron microscopy. The single olfactory opening (nostril) in Indo-Pacific sergeant is large; the olfactory rosette of an arrow-shaped type lies on the medial wall of the olfactory cavity, which is comparatively large in volume. The number of lamellae in the rosette is small; their peculiar form is associated with water flow regulation in the olfactory organ. Two ventilation sacs, large lacrimal and small ethmoidal, are attached to the olfactory cavity. The scheme of the olfactory organ ventilation is proposed. Changes in the main morphological structures of the olfactory organ with an increase in the body length of fish are observed.

Feasibility study of the positronium imaging with the J-PET tomograph

A detection system of the conventional PET tomograph is set-up to record data from annihilation into two photons with energy of 511 keV, and it gives information on the density distribution of a radiopharmaceutical in the body of the object. In this paper we explore the possibility of performing the three gamma photons imaging based on ortho-positronium annihilation, as well as the possibility of positronium mean lifetime imaging with the J-PET tomograph constructed from plastic scintillators. For this purposes simulations of the ortho-positronium formation and its annihilation into three photons were performed taking into account distributions of photons’ momenta as predicted by the theory of quantum electrodynamics and the response of the J-PET tomograph. In order to test the proposed ortho-positronium lifetime image reconstruction method, we concentrate on the decay of the ortho-positronium into three photons and applications of radiopharmaceuticals labeled with isotopes emitting a prompt gamma. The proposed method of imaging is based on the determination of hit-times and hit-positions of registered photons which enables the reconstruction of the time and position of the annihilation point as well as the lifetime of the ortho-positronium on an event-by-event basis. We have simulated the production of the positronium in point-like sources and in a cylindrical phantom composed of a set of different materials in which the ortho-positronium lifetime varied from 2.0 ns to 3.0 ns, as expected for ortho-positronium created in the human body. The presented reconstruction method for total-body J-PET like detector allows to achieve a mean lifetime resolution of ∼40 ps. Recent positron annihilation lifetime spectroscopy measurements of cancerous and healthy uterine tissues show that this sensitivity may allow to study the morphological changes in cell structures.

Effect of steam explosion on dietary fiber, polysaccharide, protein and physicochemical properties of okara

Okara is the byproduct of tofu and soymilk industries. A large amount of okara is produced annually in the world, but only a small amount is fully utilized. The effect of steam explosion (SE) treatment on dietary fiber, protein and physiochemical properties of okara was investigated in this paper. The results showed that untreated okara contained 76.38% total dietary fiber (TDF) and 18.10% protein, but the content of soluble dietary fiber (SDF) was only 1.34%. After SE treatment, SDF content increased significantly. When the SE strength was 1.5 MPa for 30s, SDF content increased to 36.28%, higher by 26 times compared to the control okara. However, the contents of TDF and SDF both decreased when the SE strength enhanced further. Gel filtration chromatography showed that molecular weight of okara polysaccharides were distributed from 55 KDa to 2087 KDa. With the increase of SE strength, the ratio of low molecular weight polysaccharides increased and the molecular weight range of polysaccharides became narrower. Okara protein showed two molecular weight peaks. After SE treatment, the area of high molecular weight peak decreased and low molecular weight peak increased. Sodium dodecyl sulfate polyacrylamide gel electrophoresis showed that okara protein appeared in five bands: 73.7 KDa, 55 KDa, 41.1 KDa, 32.7 KDa and 20.2 KDa. After SE treatment, the bands of 73.7 KDa, 55 KDa and 41.1 KDa weakened markedly, indicating high SE strength can dissociate macromolecular protein aggregates. Water solubility of okara increased significantly, while swelling capacity, oil and water holding capacities decreased after SE treatment. Scanning electron microscopy (SEM) demonstrated that the loose sheet structure of okara surface was destroyed into small fragments after SE treatment and the internal nucleated structure was disintegrated into small particles at high SE strength. The change in morphological structure also produced important influences on physiochemical properties of okara. This study suggested that SE treatment is an effective method for improving SDF content and quality of okara, so as to expand its development and utilization.

Demographic and morphological shrinkage of urban neighbourhoods in a post-socialist city: the case of Łódź, Poland

ABSTRACTThe paper contributes to the discussion concerning methods used to analyse urban shrinkage and points to the need to comprehensively examine the reasons, course and effects of the process by expanding the research perspective with morphological aspect. In accordance with theoretical assumption adopted for this paper, morphology acts as an element that complements demographic changes in the identification of urban shrinkage since the observed quantitative and qualitative changes in the urban fabric are indicative of the direction of economic and social transformations in cities. The paper aims at identifying the course of shrinkage in a selected post-socialist CEE city and discusses demographic and morphological ways of identifying the process. Łódź (Poland), one of the largest and the fastest shrinking cities in the CEE region was selected for the case study. The paper provides intra-urban scale analyses conducted at the level of individual neighbourhoods taking account of quantitative and qualitative changes in demographic and morphological structure of the city. The picture of changes at a neighbourhood level has helped identify spatial traits of urban shrinkage experienced throughout the city. Spatial scope of the area that undergoes demographic and morphological shrinkage was confronted with the crisis area intended for regeneration within the policy pursued by the city.

Three-dimensional pattern of extraretinal neovascular development in retinopathy of prematurity

The application of three-dimensional (3D) visualization techniques to evaluate the earliest visible onset of abnormal retinal vascular development in preterm infants with retinopathy of prematurity (ROP), using bedside non-contact optical coherence tomography (OCT) imaging to characterize morphology and sequential structural changes of abnormal extraretinal neovascularization. Thirty-one preterm infants undergoing routine ROP screening with written informed consent for research imaging were enrolled in this prospective observational study. We imaged the macula and temporal periphery of preterm infants using a handheld OCT system (Envisu 2300 or handheld swept-source research system). The scans obtained were segmented and, using enhanced ray casting, were converted to 3D volumes to which color filter was applied. Using colorized 3D visualization, we defined extraretinal neovascular structures as buds, bridging networks, and placoid lesions. We could longitudinally follow progression and regression of extraretinal neovascularization in stage 3 ROP after treatment in one infant over 12weeks and document the appearance of early buds, and formation of florid neovascularization. From stages 2 to 3 ROP, we observed progression from sessile buds to a complex plaque that corresponded to stage 3 ROP on clinical examination. We demonstrated regression of neovascular complexes to small pre-retinal tufts after treatment with anti-VEGF. The extension of OCT processing to include surface flattening and colorization that further improved structural analysis rendered better understanding of extraretinal tissue. Our ability to image similar areas in the same infant over multiple visits enabled us to study the evolution of these structural components and follow pathological vascular events longitudinally in development and regression after treatment. These methods can be applied to further study which are likely contribute to our understanding of the pathophysiology of neovascularization in ROP.

Abstract P2-14-18: Achiveing rapid intrao-operative diagnosis during breast cancer surgery using high-reloution full-field optical coherence imaging and dynamic cell imaging

Abstract Background: Intraoperative pathological diagnosis such as frozen section and imprint cytology is not routinely recommended in clinical practice because of time and accuracy concerns. Full-field optical coherence tomography (FF-OCT) is a new optical imaging technique that could generate sectioning tomogram from fresh tissue and provide depiction of the morphological structure and pathological changes in minutes without conventional tissue preparation, slicing, and staining, and dynamic cell imaging (DCI) added the viability information of cells/tissue, which could be more important in cancer diagnosis. This study was to evaluate the feasibility and diagnostic value of FF-OCT and DCI in breast lesions and lymph node specimens during breast cancer surgery. Methods: We evaluated normal breast tissue, benign breast lesions, breast cancer and axillary lymph node specimens from 107 patients using FF-OCT and DCI. After the optical assessment, the tissue was paraffin embedded and sent to conventional H&E diagnosis. The similar layer of OCT and H&E images were compared and diagnostic criteria were generated. The diagnostic sensitivity and specificity by two trained surgeons without pathology diagnosis experience were evaluated. Results: A total of 194 specimens were examined, including 143 breast tissue(101 malignant and 42 benign/normal) and 51 lymph nodes(26 metastatic and 25 non-metastatic). On FF-OCT and DCI, normal morphological structures such as adipose, collagen, mammary ducts, and lobules in breast tissue and lymphoid follicle and hilum in lymph nodes were easily recognized. Breast cancer characteristics on H&E imaging correspond to collagen distortion, focal hypointensity, micro-calcification, clustered or linear lively cells et etc on FF-OCT or DCI, which could also be easily distinguished. We included the previously mentioned features to build diagnosis criteria for cancer on FF-OCT and DCI. The average acquisition time is 14±11 minutes. The sensitivity and specificity for breast cancer diagnosis were 92.1% and 94.3% respectively. The sensitivity and specificity for lymph node involvement were 92.3% and 84% respectively. Conclusion: The time- and tissue-saving optical imaging technique yielded high accuracy that was comparable to that of traditional intraoperative and postoperative pathological diagnosis in breast cancer and lymph node metastasis. These results implied the promising application in the intraoperative evaluation and possible decrease of the re-excision rate for breast cancer surgery. Citation Format: Yang H, Zhang S, Guo J, Xie F, Tong F, Cao Y, Liu P, Zhou B, Cheng L, Liu M, Wang S, Peng Y, Wang C, Yang Y, Ma Y, Chen D, Shen D, Wang S. Achiveing rapid intrao-operative diagnosis during breast cancer surgery using high-reloution full-field optical coherence imaging and dynamic cell imaging [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P2-14-18.

PRECISE MONITORING OF TEMPORAL TOPOGRAPHIC CHANGE DETECTION VIA UNMANNED AIR VEHICLE

Gunumuzde hizli gelisen uzay ve hava kaynakli uzaktan algilama teknolojileri, harita, jeoloji, cevre ve madencilik gibi araziye bagli muhendislik disiplinleri icin vazgecilmez hale gelmistir. Dijital fotogrametri ve hava kaynakli lazer tarama (Airborne Laser Scanning-ALS) ile cok yuksek cozunurluklu (Very High Resolution – VHR), hizli ulasilabilen hassas nokta bulutlari sayesinde topografik yuzey tanimlamasi kolay hale gelmistir. Fotogrametrik tekniklerin en guncellerinden biri olan optik donanimli insansiz hava araclari (IHA), farkli amaclar icin oldukca revactadir. IHA’lar dusuk ucus irtifasinin avantajini kullanarak yuksek cozunurluklu veri saglamaktadir. Bu calismada, Bulent Ecevit Universitesi Kampusu icerisinde yer alan bir insaat calismasi ve onun cevresel etkileri el yapimi bir optik IHA ile gozlemlenmistir. Uygulamada, topografyaya ait es yukseklik egrileri, sayisal arazi modeli (Digital Terrain Model - DTM) ve fark DTM’leri (Differential DTM- DiffDTM) kullanilarak zamansal degisimler belirlenmistir. DiffDTM’ler kullanilarak, topografya uzerindeki degisimler, es yukseklik egrilerinin morfolojik yapinin degisimini gosteren renk yukseklik skalasi ile gorsellestirilmistir.

Morphofunctional Features of The Diaphragm in Patients With Chronic Heart Failure

to study changes in the volumes of muscle, fat, and connective tissue in postmortem issue samples (autoptates) from diaphragm, right ventricle, lower limb (gastrocnemius muscle), as well as morphological changes of the diaphragm muscular structure in patients with different functional classes of heart failure (HF), and to compare them with some intravital parameters of external respiration (with maximal inspiratory pressure and its amplitude simultaneously measured by ultrasound method in particular). Autoptates of the diaphragm muscle, right ventricle, lower limb (n=39) from 20 men and 19 women (with in vivo diagnosis CHF NYHA functional class (FC) I-IV, hypertension, ischemic heart disease) were examined within 24 hours after the fatal outcome. Light optical microscopy was used to assess the percentages of muscle, connective, adipose tissue, numbers of fibroblasts, and collagen fibers. Spirometric measurements, measurement of respiratory muscles strength, and examination of the diaphragm contractile function were performed by echolocation 56.7±11.9 days before death. In patients of all NYHA FCs most pronounced changes of volume of muscle tissue were observed in the right ventricle and diaphragm, while less pronounced - in the gastrocnemius muscle. The increase in the volume of adipose tissue in patients with I-III FC CHF was most pronounced in the right ventricle and diaphragm, and less pronounced - in the gastrocnemius muscle. The greatest increase in the adipose tissue volume was recorded in the diaphragm of patients with IV FC. Changes of connective tissue volume did not follow linear dependence. The largest "leap-like" increase in the volume of connective tissue occurred in the diaphragm of patients with III FC, what significantly outstripped this process in peripheral muscles and right ventricular myocardium. There was stable relationship between structure of tissue of the diaphragm, maximal inspiratory thickness of diaphragmatic muscle, and maximal inspiratory pressure. This relation (correlation) was positive for pairs muscle tissue volume - muscle thickness and muscle tissue volume - inspiratory pressure, and negative for pairs connective tissue volume - muscle thickness, connective tissue volume - inspiratory pressure, adipose tissue volume - inspiratory pressure (r>0.85, p<0.01 for all these correlations). Morphofunctional changes in the diaphragm are caused by progressive decrease in the content of muscle tissue, increases of volumes of adipose and connective tissues. These changes correlate with the CHF FC, maximal inspiratory thickness of diaphragmatic muscle, and maximal inspiratory pressure. Severity of these morphological changes is maximal in patients with FC III CHF.

Influences of nano zero valent ion and Fe2+ supported kaolin nanoparticles for metal ion separation thorough ultrafiltration

In this work, clay based nanocomposite material was synthesized by wet chemical route and nano zero valent ion of kaolin (nZVI:Kaolin) were prepared using sodium borohydride reduction method. The nZVI:Kaolin and Fe:Kaolin nanoparticles were characterized using XRD, FTIR and SEM and antimicrobial activity. The nZVI:Kaolin and Fe:Kaolin were incorporated into polyethersulfone (PES) membranes for metal ion separation through ultrafiltration. The influences of nZVI:Kaolin and Fe supported clay nanoparticles on PES membranes were characterized their modification in functional properties, hydrophilicity and morphological structure. The clean water flux was enhanced to PES membrane by addition of nZVI:Kaolin and Fe:Kaolin nanoparticles. The Cu (ii), Ni (ii) and Cd (ii) metal ions flux was increased for 0.15 wt% of nZVI and Fe:Kaolin nanoparticles in PES which is due to increase in hydrophilicity and change in morphological structure.

Mitigation of PEM Fuel Cell Catalyst Degradation with Porous Carbon Supports

Maintaining high performance after extensive use remains a key challenge for low-Pt proton exchange membrane fuel cells for transportation applications. Strategically improving catalyst durability requires better understanding of the relationship between degradation mechanisms and catalyst structure. To investigate the effects of the carbon support morphology, we compare the electrochemical performance and durability of membrane electrode assemblies (MEAs) using Pt and PtCox catalysts with a range of porous, solid, and intermediate carbon supports (HSC, Vulcan, and acetylene black). We find that electrochemical surface area (ECSA) retention after a catalyst-targeted durability test tends to improve with increasing support porosity. Using electron microscopy, we investigate microstructural changes in the catalysts and reveal the underlying degradation mechanisms in MEA specimens. Pt migration to the membrane and catalyst coarsening, measured microscopically, together were quantitatively consistent with the ECSA loss, indicating that these were the only two significant degradation pathways. Changes in catalyst particle size, morphology, and PtCo core-shell structure indicate that Ostwald ripening is a significant coarsening mechanism for catalysts on all carbons, while particle coalescence is only significant on the more solid carbon supports. Porous carbon supports thus appear to protect against particle coalescence, providing an effective strategy for mitigating catalyst coarsening.

The sudden death among the young persons under effect of the different forms of physical loads

The present review of the literature publications concerns the problem of sudden death (SD) among the young persons under effect of the different forms of physical loads. The statistical data on the frequency of sudden death are presented together with information about risk factors of SD, the morphological substrates and structural changes that promote death coming. The cases of sudden death among the young persons associated with the amateur sports activities and the professional sport of records are presented. The role of physical exercises and psycho-emotional stresses in the development of the terminal processes is considered with special reference to the risk factors and genetic predisposition to sudden cardiac death, largely among male athletes. The questions of sudden death in connection with cardiac pathologies as its main causes are discussed.

Mechanical alloying of iron-coated NbC and Si in stirred media mill

In the current research, the effect of mechanical alloying (MA) of iron-coated NbC and Si on the material?s fineness and crystal structure was investigated. The MA experiments were carried out in a batch-type laboratory scale stirred media mill for various residence times up to 240 min in isopropanol. During MA, milling energy was measured, and stress energy (SE) was calculated. Morphology and material structural changes, during the mechanical alloying process, were determined by means of scanning electron microscopy (SEM) and powder X-ray diffraction (XRD), respectively. The particle size distribution of the product was measured by a Horiba 950 LA laser particle size analyser. Evolution of phases during highenergy milling of NbC, Al-Fe-carbide, Fe, and Si was studied as a function of specific milling energy. Transformations in the crystal structure were revealed, namely the generation of cementite and Nb-Si-carbide, which was proved by XRD results and thermodynamic calculations. As result of the experiments, optimum MA conditions were determined. The application of the mechanical alloying method gives the opportunity to produce nanocrystalline phase from the initial ironcoated NbC and Si powder

Consequences of diabetes mellitus on neuronal connectivity in limbic regions

Diabetes mellitus (DM) is characterized by high levels of blood glucose. In recent years, its prevalence has increased, which was 422 million in the world in 2014. In elderly patients, DM is associated with deficits in memory and learning processes. The cognitive deficits lead to dementia. With the development of animal models in DM, it has been possible to better understand quantitative morphological changes in numerous neuronal structures belonging to the limbic system, such as the prefrontal cortex (PFC), the hippocampus and basolateral amygdala (BLA). These structures are in close relationship with processes of memory and learning. Several reports have demonstrated that chronic hyperglycemia reduces spinogenesis and dendritic arborization in the aforementioned regions along with a decline in memory and learning processes, especially in streptozotocin (STZ)-induced diabetic rats. In the present review, we discuss animal models, the effects of chronic hyperglycemia on dendritic morphology of limbic regions and memory and learning processes, the effect on neural transmission in these regions, the pathologic mechanisms involved, and the relevance of dendritic morphology in diabetes. All of this information can help us to have a better understanding of dementia in diabetes mellitus and propose strategies for its prevention and treatment.