Pronounced Narrowing Research Articles

Defect-induced modification of electronic and optical properties of CeO2 unveiled by many-body Green's function theory.

We explore the impact of point defects, including oxygen vacancies (Ov), cerium interstitials (Ce-int), and hydroxyl groups (Hy), on the electronic and optical properties of bulk CeO2 using many-body Green's function theory (GW method and Bethe-Salpeter equation). Although these three defects all produce occupied electronic levels near the conduction band minimum, they impose quite different effects. Ov and Ce-intinduce strong peaks in the low-energy region of the imaginary part of the microscopic dielectric function, indicating stronger electronic screening compared to the pristine CeO2. This causes pronounced narrowing of the bandgap, e.g., by 0.8eV in G0W0 and 1.6eV in the eigenvalue self-consistent GW for Ov. Comparatively, Hy affects little electronic screening and bandgap at different levels of GW calculations. For the lowest several 4f orbitals, the exchange part of the self-energy (|Σx| > 9eV) in GW is much stronger than the correlation part (|Σc| < 5eV) for Ov and Ce-int, while |Σc| is much stronger than |Σx| instead for the pristine CeO2 and Hy. Quasiparticle weights in Ov and Ce-intdecrease by a large quantity compared to the pristine CeO2. Consideration of Ov and Ce-intmight to some extent relieve the discrepancy between the GW bandgap of the pristine CeO2 and the experimental gap. Ov and Ce-intcould reduce the excitonic binding energy several times and result in optical absorption, which corresponds to the experiments.

Exploring the Relation Between Peripapillary Retinal Vessel Caliber and Visual Field Defects in Primary Open-Angle Glaucoma.

Background Primary open-angle glaucoma (POAG) is a progressive optic neuropathy characterized by loss of retinal ganglion cells, optic nerve head changes, and visual field defects. Vascular factors, alongside intraocular pressure, play a crucial role in POAG pathogenesis, and this study aims to explore the relationship between retinal vessel caliber and visual field defects in POAG patients. Purpose To evaluate the association between retinal vessel calibers in the peripapillary area with visual field defects in one or both hemifields. Materials and Methods This cross-sectional study was conducted at a tertiary eye care center in northern Karnataka for one year, enrolling 100 eyes from 50 primary open-angle glaucoma (POAG) patients with visual field abnormalities. Fundus color stereoscopic photographs were taken using a Canon digital camera, and diameters of the superior and inferior temporal arteries (STA and ITA) and veins (STV and ITV) in the peripapillary area were measured. Visual field defects were categorized, and statistical analyses were performed to correlate retinal vessel calibers with field defect locations. Results Participants had a mean age of 89.68 years, with 72% male. Visual field defects included superior arcuate scotoma (20%), inferior arcuate scotoma (32%), double arcuate scotoma (30%), and tubular vision (18%). Significant vessel caliber changes were observed: for superior hemifield defects, the mean STA: ITA ratio was 1.15 (p = 0.001), and for inferior defects, it was 0.94 (p = 0.04). STV: ITV ratios also showed significant changes corresponding to visual field defects. Eyes with defects in both hemifields showed pronounced narrowing, particularly in inferotemporal vessels. Conclusions Decreased retinal vessel caliber is significantly associated with visual field defects in primary open-angle glaucoma and can be a valuable diagnostic parameter tool for assessing glaucomatous damage and the progression and severity of POAG.

Emergence of defects-mediated diluted ferromagnetic semiconductor (ZnS: La3+) Quantum Dots: A versatile platform for optoelectronic and spintronic applications

For the first time, La3+ ions incorporated into semiconductor Zinc Sulfide-Quantum Dots (ZnS-QDs), Zn1-xLaxS, were effectively produced via a straightforward co-precipitation approach, with diverse La ratios (0.00 ≤ x ≤ 0.15 at%). The phase analysis of the acquired QDs, conducted through Raman analysis and X-ray diffractometer (XRD), revealed a singular cubic ZnS structure, devoid of any impurities. Morphology studies by HR-TEM showed a nearly spherical particle with a size of approximately 6.4 nm. X-ray photoelectron spectroscope (XPS) investigation disclosed the significant presence of sulfur vacancies, along with the existence of the trivalent oxidation state of lanthanum (La3+) within the ZnS structure. Optical absorbance studies exhibited that all QDs were positioned approximately at the absorption edges of around 270 nm (4.59 eV), surpassing the bulk ZnS energy gap of 337 nm (3.67 eV), harmonically with the quantum confinement effect. Additionally, a pronounced band gap narrowing was observed with increasing the doping level of La ions, on account of the presence of defects that result in the creation of localized states inside the ZnS band structure. The optical results indicated the capability to fine-tune the optical energy gap, dispersion parameters, and enhance the nonlinear optical parameters, which makes these QDs well-suited for use in optoelectronic devices. Furthermore, the photoluminescence (PL) spectra indicated that the La3+-doped ZnS nanocrystals (NCs) exhibited a wide visible emission band (blue emission) at room temperature, influenced by the La-doping concentration. Besides, the La3+-doped ZnS QDs elucidated ferromagnetic behavior at room temperature, which may be accredited to the vacancy-assisted bound magnetic polaron model. Exploring the intriguing magnetic features of ZnS: La3+ QDs could open avenues for developing innovative spintronic devices.

Crystal and band structures of N-doped Ti3O5 coatings: Experiments and first-principles calculations

N-doped α-phase Ti3O5 has received limited attention in both theoretical and experimental studies compared to N-doped TiO2. This work focuses on the production and analysis of N-doped Ti3O5 coatings, which can be facilely produced using air-based sputtering. First-principles calculations were employed to investigate the crystal and band structures of N-doped Ti3O5. The results revealed that substitutional nitrogen doping within the investigated range preserved the orthorhombic structure of Ti3O5. As the N-doping concentrations increased, Ti3O5 exhibited a transition from metallic to semiconducting characteristics, confirmed by the density of states and refined band calculations. The calculated bandgaps in the semiconductor regime aligned well with the limited experimental results, demonstrating the pronounced narrowing effect of nitrogen doping. Integrating these calculations with experimental findings enhances the understanding of the crystalline and physical properties of N-doped Ti3O5 coatings.

Arachnoid granulations in idiopathic intracranial hypertension: Do they have an influence?

The aim of this study was to investigate whether the relative narrowing of the dural venous sinuses by arachnoid granulations (AGs) is more pronounced in patients with idiopathic intracranial hypertension (IIH) compared to healthy controls. IIH is characterized by increased intracranial pressure, which is associated with symptoms such as headache and visual disturbances. The role of cerebral venous drainage obstruction in IIH is the subject of ongoing research. In this retrospective case-control study, 3D contrast-enhanced magnetic resonance images of a cohort of 43 patients with IIH were evaluated for (1) the number of AGs per venous sinus and (2) the diameters of the dural venous sinuses at the site of an AG and at standardized measurement points. In addition, the minimum width of the transverse/sigmoid sinus was measured. All data were compared to the same data from a cohort of 43 control participants. Patients with IIH showed less relative sinus narrowing by AG compared to controls (median: 7%, interquartile range [IQR] 10% vs. 11%, IQR 9% in controls; p = 0.009). In patients with IIH, sinus diameter was larger at the site of an AG (70 ± 25 mm2) compared to its diameter at the standardized measurement point (48 ± 23 mm2; p = 0.010). In the superior sagittal sinus (SSS), patients with IIH had smaller AGs (median: 3 mm2, IQR 2 mm2 vs. 5 mm2, IQR 3 mm2 in controls; p = 0.023) while the respective sinus segment was larger (median: 69 mm2; IQR 21 mm2 vs. 52 mm2, IQR 26 mm2 in controls; p = 0.002). The right transverse sinus was narrower in patients with IIH (41 ± 21 mm vs. 57 ± 20 mm in controls; p < 0.001). In contrast to our hypothesis, patients with IIH showed less pronounced relative sinus narrowing by AG compared to controls, especially within the SSS, where AGs were smaller and the corresponding sinus segment wider. Smaller AGs could result in lower cerebrospinal fluid resorption, favoring the development of IIH. Conversely, the smaller AGs could also be a consequence of IIH due to backpressure in the SSS because of the narrower transverse/sigmoid sinus, which widens the SSS and compresses the AG.

Association Between Automated 3D Measurement of Coronary Luminal Narrowing and Risk of Future Myocardial Infarction

This study focuses on identifying anatomical markers with predictive capacity for long-term myocardial infarction (MI) in focal coronary artery disease (CAD). Eighty future culprit lesions (FCL) and 108 non-culprit lesions (NCL) from 80 patients underwent 3D quantitative coronary angiography. The minimum lumen area (MLA), minimum lumen ratio (MLR), and vessel fractional flow reserve (vFFR) were evaluated. MLR was defined as the ratio between MLA and the cross-sectional area at the proximal lesion edge, with lower values indicating more abrupt luminal narrowing. Significant differences were observed between FCL and NCL in MLR (0.41 vs. 0.53, p < 0.001). MLR correlated inversely with translesional vFFR (r = − 0.26, p = 0.0004) and was the strongest predictor of MI at 5 years (AUC = 0.75). Lesions with MLR < 0.40 had a fourfold increased MI incidence at 5 years. MLR is a robust predictor of future adverse coronary events.Graphical The minimum lumen ratio (MLR) is defined as the ratio between the minimum lumen area (MLA) and the cross-sectional area at the proximal edge of the lesion (PROXA). A lower MLR suggests a more pronounced luminal narrowing upstream of the MLA. This specific anatomical lesion characteristic correlates with higher translesional pressure gradients and has been found to be highly predictive of lesion destabilization over a 5-year period. Notably, lesions exhibiting MLR values below 0.399 were associated with a fourfold increase in the incidence of myocardial infarction (MI) within the same timeframe.

Evaluation of dental anomalies in pupils of educational institutions of the Ministry of Defense of Russia and its impact on the level of anxiety

Relevance. Distoclusion is the most common anomaly of occlusion in childhood. Genetic predisposition, bad habits, premature loss of teeth, somatic pathologies are predisposing factors for impaired growth and development of the maxillofacial region. Pupils of general educational organizations of the Russian Ministry of Defense serve as a personnel reserve for law enforcement agencies and services, and their health, including dental health, is a priority for its preservation and strengthening Intention – To assess effects of distoclusion on the child’s social and psychological adaptation.Methodology. 50 children of 11–12 years with distoclusion (К07.20 by ICD-10) who were enrolled in the 1st year of study underwent survey along with their legal representatives to identify complaints and somatic pathology, as well as an assessment of the psychological status using the Children’s Form of Manifest Anxiety Scale (CMAS); clinical examination; photo protocol; calculation of 3D control and diagnostic models by the method of Pont, Ton, Korkhaus.Results and Discussion. When being taken anamnesis, children and their parents complained of aesthetic and functional disorders. A significant correlation was found between the narrowing of the upper jaw in the area of the premolars by (5.4 ± 0.)7 mm, in the area of the molars by (5.7 ± 1.3) mm; narrowing of the lower jaw in the area of premolars by (6.0 ± 0.3) mm and molars by (4.1 ± 0.7) mm and the psychological state of the examined children. The average CMAS level was (7.3 ± 2.3), which indicates increased anxiety in the children. 8 (16 %) pupils had a high level of anxiety and required measures of psychological correction and psychoprophylaxis.Conclusion. In pupils with distoclusion, there is a pronounced narrowing of the dentition in the area of premolars and molars, significant overjet, protrusion of the anterior group of teeth, which affects the aesthetic perception by others and is reflected in the psychological state of the examined children.

QUANTITATIVE MORPHOLOGICAL ASPECTS OF THE STUDY OF THE FEATURES OF THE REMODELING OF THE HEMOMICROCIRCULATORY CHANNEL OF THE TESTICLES UNDER THE ACTION OF ALUMINUM CHLORIDE ON THE BODY.

The aim: To conduct a morphometric analysis of the features of the remodeling of vessels of the hemomicrocirculatory channel of the testicles under the action of aluminum chloride on the body. Materials and methods: The testicles of 52 white male Wistar rats were morphologically studied, which were divided into two groups: intact and animals injected with aluminum chloride at a dose of 100 mg/kg. Results: The long-term effect of aluminum chloride on the body led to pronounced changes in the quantitative morphological indicators of the vessels of the hemomicrocirculatory channel of the testes compared to the control ones. The diameter of arterioles of the left testicle decreased by 18.4%, precapillary arterioles by 19.1%, hemocapillaries by 10.1%. The diameter of the postcapillary venules of the left testicle increased by 26.3%, the venules by 26.4%, and the density of microvessels decreased by 30.0%, which indicated the deterioration of its blood supply. The degree of remodeling of microvessels in the right testis was less pronounced. The diameter of arterioles of the right testicle decreased by 17.1%, precapillary arterioles by 18.4 %, and hemocapillaris by 9.1%. The diameter of the postcapillary venules of the right testicle increased by 25.5%, the venules by 27.0%, and the density of microvessels decreased by 25.8%. Conclusions: Long-term action (during the month) of aluminum chloride on the body leads to pronounced remodeling of the vessels of the hemomicrocirculatory channel of the testicles, which is characterized by a pronounced narrowing of its supply (arterioles, precapillary arterioles), exchange (hemocapillaries) links.

Сравнительная клиническая эффективность кальций-силикатных цементов и кальция гидроксида в витальной терапии пульпы постоянных зубов

BACKGROUND: Preservation of pulp viability allows to preserve the integrity of tooth structures, the correct relationship with other elements of the dental system, therefore, the improvement of materials aimed at preventing endodontic treatment with preservation of the entire pulp is of great clinical importance. AIM: Comparison of clinical effectiveness of various materials in the vital therapy of permanent tooth pulp. MATERIALS AND METHODS: The study involved 30 patients (20 male and 10 female patients aged 11 to 25 years) divided into 3 groups. Vital pulp therapy of permanent molars and premolars with formed and unformed roots diagnosed as reversible pulpitis was carried out by direct and indirect coating with calcium hydroxide in group 1 (9 patients/18 teeth) (Calasept, with Dycal-isolated surface), with ProRootMTA in group 2 (10 patients/15 teeth) and with Biodentine in group 3 (11 patients/15 teeth). IRM (methyl methacrylate-reinforced zink-oxide-eugenol cement) was used as temporary filling. The research data were processed using nonparametric statistics. RESULTS: After 4 years of follow-up: After the first stage of observation, not in a single of 14 remaining teeth in group 1 (4 teeth were subjected to endodontic treatment), clinical and radiological signs of pulp pathology were found; in 3 teeth (21.4%), pronounced narrowing of the pulp chamber and obliteration of the pulp of canal orifice were noted, which did not require endodontic intervention. In group 2, of 13 teeth (2 teeth previously received endodontic treatment), 1 tooth (7.6%) was diagnosed with irreversible symptomatic pulpitis and 2 teeth (16.6%) — with pronounced narrowing of the pulp chamber, obliteration of the root pulp, 3 teeth (25%) — with denticles in the pulp chamber. In group 3, 2 teeth (13.3% of cases) were subjected to endodontic treatment for irreversible symptomatic pulpitis in 1.5 year after the beginning of the observation, and in 1 tooth (6.6%), the formation of multiple denticles in the pulp chamber was noted. CONCLUSION: Thus, the clinical and radiological effectiveness of use of calcium hydroxide in vital pulp therapy of permanent teeth after 12 months was 77.7% (14 of 18 teeth), of ProRootMTA — 86.6% (13 of 15 teeth) and of Biodentine — 100%, which absolutely correlates with the data of modern literature sources. In direct pulp coating (pulpcap) in permanent teeth, 100% excellent treatment results within 1 year were achieved only with Biodentine.

Оценка синовита голеностопного сустава при диабетической нейроостеоартропатии в зависимости от воспалительной фазы хронического остеомиелита

Diabetic neuroosteoarthropathy complicated by osteomyelitis is one of the severe conditions of the ankle joint in patients with diabetes. The role of the synovium in the pathogenesis of this disease remains poorly understood. Purpose To identify structural changes in the synovium of the Charcot ankle depending on the inflammatory phase of chronic osteomyelitis. Material and methods The synovium and osteochondral fragments of the ankle were studied in 33 patients. Paraffin sections stained according to the three-color Masson method, hematoxylin and eosin, and semi-thin sections stained with methylene blue and basic fuchsin were studied using an AxioScope. A1 microscope with an AxioCam digital camera (Carl Zeiss MicroImaging GmbH, Germany) and Zenblue software (Carl Zeiss MicroImaging GmbH, Germany). The phase of the inflammatory process of chronic osteomyelitis was assessed according to the HOES of Tiemann et al (2014) and synovitis according to Krenn et al (2006). Results Full-thickness articular cartilage defects, synovial pannus, foci of osteonecrosis in the subchondral zone, bone microsequesters, osteoclastic resorption of the subchondral bone plate, replacement of bone marrow structures with granulation tissue, the severity which depended on the inflammatory stage of chronic osteomyelitis, were recorded in the process of studying osteochondral fragments. In 82 % of patients, the inflammatory phase of chronic osteomyelitis was characterized as active and subacute. In all the cases, hyperplasia, hypervascularization and hyperemia of the synovium with the presence of bone and cartilage fragments were observed, as well as inflammatory infiltrate, synovial pannus invading the articular cartilage. The vessels featured a pronounced narrowing of the lumens or their complete closure. The severity of synovitis correlated positively with the inflammatory phase of chronic osteomyelitis; Spearman's correlation coefficient of 0.76 indicated high relationship. Conclusions In diabetic osteoarthropathy of the ankle joint complicated by chronic osteomyelitis, the irreversible structural changes revealed in the synovium contribute to the formation of synovial pannus and the progression of destruction of the articular cartilage and subchondral bone. The severity of synovitis positively correlates with the inflammatory phase of chronic osteomyelitis.

Impact of Postthrombotic Vein Wall Biomechanics on Luminal Flow during Venous Angioplasty and Stent Placement: Computational Modeling Results

This study characterized the impact of vein wall biomechanics on inflow diameter and luminal flow during venous angioplasty and stent placement, using postthrombotic and healthy biomechanical properties from an ovine venous stenosis and thrombosis model. Finite element analysis demonstrated more pronounced inflow channel narrowing in the postthrombotic vein compared with the healthy control vein during angioplasty and stent placement (relative inflow diameter reduction of 42% versus 13%, P < .0001). Computational fluid dynamics modeling showed increased relative areas of low wall shear rate in the postthrombotic vein compared with the normal vein (0.46 vs 0.24 for shear rate < 50 s−1; 0.13 vs 0.07 for shear rate < 15 s−1; P < .05), with flow stagnation and recirculation. Since inflow narrowing and low wall shear rate are associated with in-stent restenosis and reintervention, these computational results based on experimentally obtained biomechanical values highlight the significance of postthrombotic venous properties in optimizing venous intervention outcomes.

Peculiarities of the upper airways condition in patients with snoring and obstructive apnea during sleeping

Aim: study the anatomical features of the upper respiratory tract in patients with ronchopathy of varying degrees of clinical manifestations. Materials and methods: 60 patients with persistent snoring were under supervision. They were divided into four clinical groups depending on the degree of snoring and obstructive sleep apnea. All patients underwent clinical and instrumental examination, which included cardio-respiratory monitoring and MRI examination of the upper respiratory tract. Results: In the comparative analysis of results of clinical studies of the upper respiratory tract of patients with and without obstructive sleeping apnea, there was a statistically significant narrowing of the retroglossal space in 45,7% and 16%, respectively. In the analysis of morphometric parameters of the upper respiratory tract in patients with sleep-disordered breathing of varying severity, there was a narrowing of the retropalatinal and retroglossal lumens of the pharynx due to the increase in the soft palate and tongue with its dislocation posteriorly. It is stated that more pronounced narrowing of the lumen of the upper respiratory tract leads to respiratory disorders during sleeping. The most severe manifestation of respiration deterioration during sleeping were observed in the narrowing of the upper respiratory tract at several levels.

Pronounced Linewidth Narrowing of Vertical Metallic Split-Ring Resonators via Strong Coupling with Metal Surface.

We theoretically study the plasmonic coupling between magnetic plasmon resonances (MPRs) and propagating surface plasmon polaritons (SPPs) in a three-dimensional (3D) metamaterial consisting of vertical Au split-ring resonators (VSRRs) array on Au substrate. By placing the VSRRs directly onto the Au substrate to remove the dielectric substrates effect, the interaction between MPRs of VSRRs and the SPP mode on the Au substrate can generate an ultranarrow-band hybrid mode with full width at half maximum (FWHM) of 2.2 nm and significantly enhanced magnetic fields, compared to that of VSRRs on dielectric substrates. Owing to the strong coupling, an anti-crossing effect similar to Rabi splitting in atomic physics is also obtained. Our proposed 3D metamaterial on a metal substrate shows high sensitivity (S = 830 nm/RIU) and figure of merit (FOM = 377), which could pave way for the label-free biomedical sensing.

Optical outcoupling in monochromatic top-emitting organic light-emitting diodes with an Au/Ag semi-transparent electrode

Top-emitting organic light-emitting diodes can achieve high efficiencies due to the strong cavity effect resulting from the relatively thick semi-transparent metallic top electrode. The strong cavity resonance, however, simultaneously brings along negative side effects such as pronounced angular-dependent emission and spectral narrowing. In this work, through numerical simulations, we demonstrate that top-emitting organic light-emitting diodes using a thin Au(2 nm)/Ag(7 nm) top electrode can achieve light-outcoupling efficiency comparable to a thick silver electrode, while reducing spectral narrowing. This can be realized by tuning the organic capping layer thickness without affecting the electrical properties, which can be applied to diodes based on either intrinsic or efficiently doped charge transport layers.

Predictors of suicidal behavior in patients with cognitive impairments in depressive disorders

The aim of the study was to determine predictors of suicide risk in patients with cognitive impairment in depressive disorders.Material and methods. 362 patients with cognitive impairment in depressive disorders were examined: 123 patients with recurrent depressive disorder, 141 patients with bipolar affective disorder and 98 patients with prolonged depressive reaction. A set of research methods was used to study the factors of suicidal behavior in patients with cognitive impairment in depressive disorders: clinical-psychopathological, psychodiagnostic (questionnaire "Self-assessment of the severity of autoaggressive predictors") and mathematical-statistical. Results of the research. Predictors of suicide risk in patients with cognitive impairment in depressive disorders were identified. The moderate level of autoaggression and aggression, low level of impulsivity, high and severe narrowing of cognitive functions, severe narrowing of interpersonal relationships, severity of affective disorders, moderate and severe autonomic disorders were identified in patients with recurrent depressive disorder. Pronounced and moderate level of autoaggression, aggression and impulsivity, high and pronounced level of narrowing of cognitive functions, pronounced narrowing of interpersonal relationships, severity of affective disorders, moderate and severe level of autonomic disorders were identified in patients with bipolar affective disorder. Moderate levels of autoaggression and narrowing of cognitive functions, low levels of aggression, severe impulsivity, affective disorders and narrowing of interpersonal relationships, and high levels of autonomic disorders were identified in patients with prolonged depressive reaction.Conclusions. As a result of the study, the features of suicidal behavior in patients with cognitive impairment in depressive disorders were identified. It can act as diagnostic criteria and predictors of suicidal behavior in differential diagnostics and could take into account when creating psychocorrectional programs aimed at reducing suicidal risk in patients with cognitive dysfunctions in depressive disorders.

Metal Nanoparticle Film Deposition by Femtosecond Laser Ablation at Atmospheric Pressure.

Nanoparticle gold films were deposited using femtosecond laser ablation in argon at atmospheric pressure in an arrangement where a flat Au target was irradiated through a transparent substrate in close proximity. Spatially extended films were made by rastering the target and substrate assembly together in the laser beam. Fast imaging clearly showed pronounced narrowing of the ablation plume, which can be understood in terms of laser induced multiphoton ionisation and heating of the gas near the ablation site. Deposition was possible for target-substrate separation up to 2 mm. The equivalent thickness of the nanoparticle film was controlled in the range 0.4–28 nm by changing the target-substrate separation and the shot-to-shot spacing of ablation spot raster. The mean Feret diameter varied in the range 14–40 nm depending on the deposition conditions, and all the films showed a surface plasmon resonance at about 525 nm, which was nearly independent of the equivalent thickness. The technique can readily be applied to other materials for the fabrication of nanoparticulate films at atmospheric pressure.

Study of gamma-ray effects on relaxation oscillator based on unijunction transistor

The object of this research is all the semiconductor unijunction transistor device (UJT) parameters that affect its operation as 1.67 kHz saw-tooth relaxation oscillator circuit under the influence of gamma-irradiation dose. Relaxation oscillators are widely used in function generators, electronic beepers, inverters, blinkers, and voltage-controlled oscillators. The properties of UJTs are like those of other semiconductor devices are greatly affect by irradiation. Its electrical characteristics and the output voltage waveforms of the relaxation oscillator circuit were investigated and plotted as a function of different gamma-dose levels. The type of semiconductor, the design of the device and the type of radiation are affected the magnitude of this change. Where, it is shown that increasing gamma dose up to 3.0 MGy leads, the peak voltage (VP) to be decreased from 3.71 Volts down to 2.9 Volts, while the valley voltage (VV) to be increases from 1.54 Volts up to 1.89 Volts, leading to a pronounced narrowing on the negative resistance region. As a result, both the output signal voltage amplitude and the frequency of the relaxation oscillator circuit were shown to be functions of the gamma-irradiation dose. Where, the initial values of the output signal voltage amplitude were reported to be 2.54 Volts decreased to the value of 2.13 Volts, while its frequency was 1.67 kHz increased up to 1.85 kHz, respectively, due to gamma-exposure levels up to 3.0 MGy using the GammaCell-220 (National Center for Radiation Research and Technology of Egypt).

Fibromuscular dysplasia of aortic aneurysm vasa vasorum (a rare case report)

Aim. To describe a rare occurrence of fibromuscular vasa vasorum dysplasia of the aortic aneurysm wall.Materials and methods. Surgical material from the ascending aortic aneurysm wall was examined. Longitudinal strips of the aortic wall were excised for histological examination with subsequent 24-h fixation in 10% buffered formalin. A histological isopropanol assay was performed with an automated Logos microwave tissue processor (Milestone, Italy) with subsequent sample embedding into paraffin. Sections were obtained with a rotary microtome (Leica, Germany). Staining was performed with haematoxylin-eosin, van Gieson’s picrofuchsin, orcein for elastic fibres, Hotchkiss’ PAS reaction with alcian blue for glycosaminoglycans. Histological and histochemical properties of the aortic wall were studied and imaged with a Leica DM 1000 microscope (Germany) equipped with a camera ICC50 E at magnifications 40x, 100x, 200x, 400x.Results. The conducted histological examination of the aortic aneurysm wall revealed most pronounced changes in media and adventitia layers. Elastic fibres in media were swollen, homogeneous, crimped, with pronounced dystrophic and necrobiotic changes in smooth myocytes. Regions of compromised cells and elastic fibres in media contained pockets of alcian-positive glycosaminoglycans. Specific changes were revealed in adventitia vasa vasorum in the form of a pronounced wall thickening and lumen narrowing due to dysplastic fibromuscular tissues.Conclusion. A rare form of fibromuscular dysplasia of the vasa vasorum of the ascending aortic aneurysm wall observed in a 43 years-old woman demonstrated the morbid morphology of smooth myocytes, as well as fibrous collagenous and elastic structures. The described features were likely associated with the aortic wall trophic structure and aneurysm morphogenesis.

CURRENT ASPECTS OF CORONARY HEART DISEASE DIAGNOSIS AND TREATMENT

Among the cardiovascular diseases associated with atherosclerosis, chronic coronary heart disease, including angina, is the most common form. It is the myocardium lesion that develops as a result of an imbalance between the coronary circulation and metabolic needs of heart muscle. The presence of angina symptoms often indicates a pronounced narrowing of one or more coronary arteries, but also occurs in non−obstructive arterial impairment and even in normal coronary arteries. Factors of functional damage to the coronary arteries are spasm, temporary platelet aggregation and intravascular thrombosis. Today there are opportunities not only to use the therapy with proven effectiveness, aimed at reducing the risk of complications, including fatal, but also to treat angina (ischemia), which improves the patient's life quality. The drug protocol includes the ones with a proven positive effect on this disease prognosis, which are mandatory if there are no direct contraindications to use, as well as a large group of antianginal or anti−ischemic drugs. The choice of a particular drug or its combinations with other drugs is carried out in accordance with generally accepted recommendations: taking into account the individual approach, the severity of angina, hemodynamic parameters (heart rate and blood pressure, presence of comorbid conditions). If drug therapy is ineffective, the option of coronary myocardial revascularization (percutaneous coronary angioplasty or coronary artery bypass grafting) is considered. Due to the high mortality and morbidity rates of coronary heart disease worldwide, one of the priorities of practical health care is the prevention of diseases caused by atherosclerosis. Key words: coronary heart disease, angina, family physician, prognosis, drug therapy.

Abstract 166: Physiological Effects of Adrenaline in Human Cardiac Arrest With Pulseless Electrical Activity: A Pilot Study

Introduction: During resuscitation from cardiac arrest with Pulseless Electrical Activity (PEA), studies show that adrenaline facilitates return of spontaneous circulation (ROSC) and possibly leads to an isolated increase in the heart rate (HR). In this study, we investigated the immediate effects of adrenaline on ECG characteristics; HR and QRS duration (duration of ventricle depolarization). Method: We studied 19 ECG segments of 300 s duration from emergency defibrillators in 10 adult patients during resuscitation from in-hospital cardiac arrest. Information on the exact timing of adrenaline administration (between 0.5 and 1 mg i.v.) was obtained from the defibrillators or the emergency personnel involved. HR (1/min) and QRS duration (ms) were annotated and registered using an ad-hoc Matlab (Mathworks, Natic, MA) graphical Data Annotator, and interpolated linearly between individual observations. Trends were identified with LOWESS. Results: The plots show the individual observations (red points) along with the trends (blue lines) of HR and QRS Duration during resuscitation, relative to the time of adrenaline administration. We observed a gradual increase in heart rate (peaking at 150 s after adrenaline administration) and a more pronounced narrowing of the QRS (levelling off also at about 150 s). Discussion: In this pilot study, administration of adrenaline was associated with narrowing of the QRS complex, while the relation to heart rate was less apparent. A limitation is that no adjustment for the individual patient’s trajectory was made. However, the results are fairly consistent with earlier studies on out-of-hospital resuscitation, when adrenaline was typically given much later.