Characterization of nanoscale atomic motion of Si in polycrystalline Cu layer.

Atomic migration of silicon through grain boundaries of a thin polycrystalline Cu film and island formation on the Cu surface were studied in the temperature range of 403-520 K. Samples used in these experiments was prepared on Si(111) wafers by room temperature magnetron sputtering and they consisted of amorphous Si layer (80 nm) and polycrystalline Cu layer (40 nm). The silicon layer served as the source layer of diffusion, while the copper surface was the accumulation surface. Detection of Si atoms on the accumulation surface after penetration through the Cu layer was made by low energy ion scattering spectroscopy and the grain boundary diffusion coefficient DGB was determined from the appearance time. The depth distribution of Si in the Cu film was analysed by secondary neutral mass spectroscopy. From this depth distribution, DGB was also determined. By scanning probe microscope and electron microscope measurements, it was experimentally detected that Si atoms on the Cu surface did not form a continuous layer. Instead, amorphous Si islands were formed at the accumulation surface with surface protrusions in their centres.

Experimental Analysis and Optimization Approach of Self-Clocked Rate Adaptation for Multimedia Congestion Control Algorithm in Emulated 5G Environment.

The congestion problem has driven many researchers to address it, among other networking issues. In a packet-switched network, congestion is essential; it leads to a high response time to deliver packets due to heavy traffic, which eventually causes packet loss. Hence, congestion control mechanisms are utilized to prevent such cases. Several interesting algorithms are proposed to focus on this dilemma, such as the Self-Clocked Rate Adaptation for Multimedia (SCReAM) designed for interactive real-time video streaming applications. One of the main issues of SCReAM is the high design complexity due to the large size of its documentation and coding. Furthermore, there is a considerable number of parameters that can be adjusted to accomplish the desired performance. This study proposes a guided parameters' tuning approach to assess and optimize the SCReAM algorithm in an emulated 5G environment through a detailed exploration of its parameters. The proposed approach consists of three phases, namely, the initialization phase, the standalone experimentation phase, and the hybrid experimentation phase. In the first phase, we illustrate the method of initializing and implementing the environment, followed by specifying the investigated parameters' settings, testing, and validation. The second phase aims to investigate SCReAM parameters in isolation to identify the effect on the performance in relation to network queue delay, smoothed Round Trip Time (sRTT), and throughput. The final phase discusses the possibility of achieving the optimum performance by combining various sets to provide researchers with clear and explicit guidelines to establish an adequate SCReAM behavior for the desired application. To the best of our knowledge, this is the first study that proposes a preliminary and comprehensive analysis of the SCReAM algorithm. Based on the proposed approach, when L4S/ECN is disabled, we reduced the network queue delay by 63.36% and increased the network throughput by 48.6% as compared to the results generated by the original design. In L4S/ECN-enabled mode, the network queue delay is reduced by 16.17% while the network throughput increased by 93%.

Leveraging Blockchain Technology for Ensuring Security and Privacy Aspects in Internet of Things: A Systematic Literature Review.

As the Internet of Things (IoT) concept materialized worldwide in complex ecosystems, the related data security and privacy issues became apparent. While the system elements and their communication paths could be protected individually, generic, ecosystem-wide approaches were sought after as well. On a parallel timeline to IoT, the concept of distributed ledgers and blockchains came into the technological limelight. Blockchains offer many advantageous features in relation to enhanced security, anonymity, increased capacity, and peer-to-peer capabilities. Although blockchain technology can provide IoT with effective and efficient solutions, there are many challenges related to various aspects of integrating these technologies. While security, anonymity/data privacy, and smart contract-related features are apparently advantageous for blockchain technologies (BCT), there are challenges in relation to storage capacity/scalability, resource utilization, transaction rate scalability, predictability, and legal issues. This paper provides a systematic review on state-of-the-art approaches of BCT and IoT integration, specifically in order to solve certain security- and privacy-related issues. The paper first provides a brief overview of BCT and IoT's basic principles, including their architecture, protocols and consensus algorithms, characteristics, and the challenges of integrating them. Afterwards, it describes the survey methodology, including the search strategy, eligibility criteria, selection results, and characteristics of the included articles. Later, we highlight the findings of this study which illustrates different works that addressed the integration of blockchain technology and IoT to tackle various aspects of privacy and security, which are followed by a categorization of applications that have been investigated with different characteristics, such as their primary information, objective, development level, target application, type of blockchain and platform, consensus algorithm, evaluation environment and metrics, future works or open issues (if any), and further notes for consideration. Furthermore, a detailed discussion of all articles is included from an architectural and operational perspective. Finally, we cover major gaps and future considerations that can be taken into account when integrating blockchain technology with IoT.

Vesicovaginal fistula repair after a failed Lehoczky's island flap procedure.

Vesicovaginal fistula (VVF) is the most common genitourinary fistula associated with significant, detrimental impact on the quality of life. Surgical repair of VVF may be complex requiring tissue interposition techniques to bring fresh blood supply, minimize recurrence, and improve functional outcomes. The international literature is scarce regarding complications related to interposition tissue. However, caution is particularly recommended in selecting the tissue interposition technique to avoid unexpected and frustrating problems. We present a 57-year-old woman following multiple failed transvaginal and transabdominal VVF repairs involving a labium majus skin island flap (Lehoczky flap) after radical hysterectomy for cervical cancer.

Utilization of acute vascular imaging and neurointervention for acute ischaemic stroke patients in 20 Hungarian stroke centers.

BACKGROUND AND PURPOSE: Acute mortality rate of stroke in Hungary is significantly higher than in Western Europe, which is likely to be partially attributable to suboptimal treatment. METHODS: We examined the use of acute vascular imaging and mechanical thrombectomy for acute ischaemic stroke patients. We collected data on 20 consecutive patients from Hungarian stroke centers before 31st August 2016. RESULTS: Out of the reported 410 patients, 166 (40.4%) underwent CT angiography and 44 (10.7%) had mechanical thrombectomy. CONCLUSION: Only about 1/3 of acute ischaemic stroke patients eligible for thrombectomy actually had it. The underlying reasons include long onset-to-door time, low utilization of acute vessel imaging and a limited neuro-intervention capacity needing improvement.

Comparing the agrochemical properties of compost and vermicomposts produced from municipal sewage sludge digestate.

The aim of this work was to investigate whether the agronomic traits of vermicompost prepared from partially stabilised sewage sludge digestate after thermophilic composting were more favourable than those of conventional compost. The effects of various additives (green waste, spent mushroom compost, wheat straw, biochar) were also tested after 1.5 months precomposting followed by 3 months vermicomposting with Eisenia fetida or by compost maturing. Vermicomposting did not result in significantly more intensive mineralisation than composting; the average organic carbon contents were 21.2 and 22.2% in vermicomposts and composts, respectively. Hence, the average total (N: 2.4%; P: 1.9%; K: 0.9%) and available (N: 160 mg/kg; P: 161 mg/kg; K: 0.8%) macronutrient concentrations were the same in both treatments. The processing method did not influence the organic matter quality (E4/E6) either. However, on average the concentration of the plant growth regulator kinetin was more than twice as high in vermicomposts.

Hypertension-induced subclinical vascular and cognitive changes are reversible-An observational cohort study.

Beside the well-known complications of poorly controlled, long-standing hypertension, milder abnormalities induced by early-stage hypertension have also been described. In our study, the authors examined the reversibility of changes induced by early-stage hypertension. The authors performed laboratory testing, ambulatory blood pressure monitoring, carotid intima-media thickness (IMT) measurement, evaluation of stiffness parameters, assessment of various cardiac and cerebral hemodynamic parameters during head-up tilt table (HUTT) testing, and neuropsychological examinations in 49 recently diagnosed hypertensive patients. Following baseline assessment, antihypertensive therapy was commenced. After one year of therapy, lower IMT values were found. Pulse wave velocity showed a borderline significant decrease. During HUTT, several hemodynamic parameters improved. The patients performed better on neuropsychological testing and reached significantly lower scores on questionnaires evaluating anxiety. The present study shows that early vascular changes and altered cognitive function observed in newly diagnosed hypertensive patients may improve with promptly initiated antihypertensive management.

A two-agent model applied to the biological control of the sugarcane borer (Diatraea saccharalis) by the egg parasitoid Trichogramma galloi and the larvae parasitoid Cotesia flavipes.

The paper is aimed at a methodological development in biological pest control. The considered one pest two-agent system is modelled as a verticum-type system. Originally, linear verticum-type systems were introduced by one of the authors for modelling certain industrial systems. These systems are hierarchically composed of linear subsystems such that a part of the state variables of each subsystem affect the dynamics of the next subsystem. Recently, verticum-type system models have been applied to population ecology as well, which required the extension of the concept a verticum-type system to the nonlinear case. In the present paper the general concepts and technics of nonlinear verticum-type control systems are used to obtain biological control strategies in a two-agent system. For the illustration of this verticum-type control, these tools of mathematical systems theory are applied to a dynamic model of interactions between the egg and larvae populations of the sugarcane borer (Diatraea saccharalis) and its parasitoids: the egg parasitoid Trichogramma galloi and the larvae parasitoid Cotesia flavipes. In this application a key role is played by the concept of controllability, which means that it is possible to steer the system to an equilibrium in given time. In addition to a usual linearization, the basic idea is a decomposition of the control of the whole system into the control of the subsystems, making use of the verticum structure of the population system. The main aim of this study is to show several advantages of the verticum (or decomposition) approach over the classical control theoretical model (without decomposition). For example, in the case of verticum control the pest larval density decreases below the critical threshold value much quicker than without decomposition. Furthermore, it is also shown that the verticum approach may be better even in terms of cost effectiveness. The presented optimal control methodology also turned out to be an efficient tool for the "in silico" analysis of the cost-effectiveness of different biocontrol strategies, e.g. by answering the question how far it is cost-effective to speed up the reduction of the pest larvae density, or along which trajectory this reduction should be carried out.

Elevated LDL-C combined with hypertension worsens subclinical vascular impairment and cognitive function.

Hypertension and dyslipidemia belong to the most prevalent modifiable risk factors for cerebrovascular and cardiovascular diseases. Hereby, we aimed to examine the combined effects of newly diagnosed hypertension and hyperlipidemia on the characteristics of the arterial wall and on cognitive function. We examined 72 hypertensive and 85 apparently healthy individuals. Based on serum lipid levels, four subgroups were created ranging from normotensive-normolipidemic to hypertensive-hyperlipidemic subjects. Carotid intima-media thickness (IMT), arterial stiffness, and cognitive function were assessed. IMT of controls was the lowest, whereas that of patients with both risk factors the highest. Stiffness parameters increased when both risk factors were present, whereas subjects with only one risk factor exhibited intermediate values. Hypertensive patients performed worse when memory, attention, reaction time, and trait anxiety were assessed. Significant worsening of IMT, arterial stiffness, and sum of neuropsychological scores was observed along with increasing mean arterial pressure. Generally, hyperlipidemia combining with hypertension resulted in further worsening of all examined parameters. Subclinical changes of the vascular wall and cognitive performance are already present in recently diagnosed hypertensive patients. Combination of hyperlipidemia and hypertension results in more severe impairments, therefore, early and intensive treatment may be crucial to prevent further deterioration.

Anxiety, depression and autonomic nervous system dysfunction in hypertension.

OBJECTIVES: This study examined the relationship between autonomic nervous system dysfunction, anxiety and depression in untreated hypertension. PATIENTS AND METHODS: 86 newly diagnosed hypertensive patients and 98 healthy volunteers were included in the study. The psychological parameters were assessed with Spielberger State-Trait Anxiety Inventory and Beck Depression Inventory by a skilled psychologist. Autonomic parameters were examined during tilt table examination (10min lying position, 10min passive tilt). Heart rate variability (HRV) was calculated by autoregressive methods. Baroreflex sensitivity (BRS) was calculated by non-invasive sequence method from the recorded beat to beat blood pressure values and RR intervals. RESULTS: Significantly higher state (42.6±9.3 vs. 39.6±10.7 p=0.05) and trait (40.1±8.9 vs. 35.1±8.6, p<0.0001) anxiety scores were found in the hypertension group. There was no statistically significant difference in the depression level. LF-RRI (Low Frequency-RR interval) of HRV in passive tilt (377.3±430.6 vs. 494.1±547, p=0.049) and mean BRS slope (11.4±5.5 vs. 13.2±6.4, p=0.07) in lying position were lower in hypertensives. Trait anxiety score correlates significantly with sympatho/vagal balance (LF/HF-RRI) in passive tilt position (Spearman R=-0.286, p=0.01). CONCLUSIONS: Anxiety could play a more important role than depression in the development of hypertension. Altered autonomic control of the heart could be one of the pathophysiological links between hypertension and psychological factors.

Cerebro- and cardiovascular reactivity and neuropsychological performance in hypertensive patients.

BACKGROUND: Hypertensive (HT) patients are at higher risk of cognitive decline than normotensive individuals, because high blood pressure is a risk factor for mild cognitive deterioration. In this study cardio- and cerebrovascular reactivity along with cognitive performance was assessed on newly diagnosed HT patients. METHODS: Diagnosis of hypertension was based on international recommendations. None of the patients had diabetes, and all of them had normal cerebral CT scan. Eighty-one patients (43.5±10.2 years, male/female ratio: 42/39) were compared with 94 healthy controls (44±9.4 years, male/female ratio: 50/44). In both groups continuous, non-invasive and simultaneous monitoring of cerebral and cardiac hemodynamical parameters were recorded during head-up tilt table testing (HUTT). Reaction time, attention and memory skills, anxiety and depression rate were determined by neuropsychological tests. RESULTS: During HUTT significant differences were found in certain cardiovascular parameters (blood pressure, total peripheral resistance index, stroke index), but no differences were detected in cerebral blood flow velocity. While there was no significant difference in reaction time between the two groups, tests estimating short-term memory (Digit Span Test) differed significantly. Moreover, sum of standardized test scores was significantly lower, while anxiety level was significantly increased in HT patients compared to controls. CONCLUSION: Decrease in neuropsychological performance along with alterations of cardiovascular parameters is an early manifestation of hypertension. Aim for an early intervention and accurate treatment is crucial for preventing further impairments.

[Management of Fabry disease]. / Fabry-betegség - terápiás útmutató

Fabry disease is a rare, X-linked lysosomal storage disorder that leads to accumulation of globotriaosylceramide in different tissues of the body. The disease is progressive and the first symptoms usually present in childhood. Consequences of the disease are disability and premature death. The disease in females could be as severe as in males although women may be asymptomatic. The possibility of enzyme replacement therapy has made it necessary to elaborate a comprehensive guideline for the diagnosis and treatment follow-up. The guideline has been summarized by a Hungarian multi-disciplinary working group consisting of physicians who are involved in diagnosis and care of Fabry patients. Previous clinical studies, published articles, and recently established international treatment guidelines were reviewed by the group.

[Fabry disease--diagnostic guideline]. / Fabry-betegség. Diagnosztikai útmutató.

Fabry disease is a rare, X-linked lysosomal storage disorder that leads to accumulation of globotriaosylceramide in different tissues of the body. The disease is progressive, first symptoms usually present in childhood. Consequencies of the diseases are disability and premature death. The disease in females could be as severe as in males although women may also be asymptomatic. The possibility of enzyme replacement therapy has made it necessary to elaborate a comprehensive guideline for the diagnosis and treatment follow-up. The guideline was established by a Hungarian multi-disciplinary working group, consisting of physicians who are involved in health care of Fabry patients. Previous clinical studies, published materials, and recently established international treatment guidelines were reviewed by the group.

Effect of smoking cessation on visually evoked cerebral blood flow response in healthy volunteers.

BACKGROUND/AIMS: In our previous study, impaired visually evoked flow velocity response was demonstrated in young chronic smokers. Our aim was to study whether impaired cerebrovascular reactivity is reversible 6-18 months after smoking cessation. METHODS: Flow velocity changes, evoked by visual stimulus, were recorded in the posterior cerebral arteries in 15 smokers, 15 former smokers and 15 nonsmokers. The stimulation protocol consisted of 10 cycles with a resting phase of 20 s (baseline) and a stimulating phase of 40 s for each cycle. Relative changes of flow velocity were expressed in relation to baseline. Breath holding index, visual evoked potential and intima-media thickness were also examined. RESULTS: Repeated measures ANOVA revealed marked difference in the flow velocity time courses between the 3 groups (p < 0.01). The flow response was significantly worse in former smokers than in nonsmokers (p < 0.002), however, no significant difference was found between former and current smokers (p = 0.0556). CONCLUSION: This is the first transcranial Doppler study demonstrating long-term impairment of visually evoked cerebrovascular response after smoking cessation. These findings indicate that the impairment of neurovascular coupling caused by smoking is due to structural changes of the vessels, rather than acute effect of smoking.

Acetazolamide-induced vasodilation does not inhibit the visually evoked flow response.

Different methods are used to assess the vasodilator ability of cerebral blood vessels; however, the exact mechanism of cerebral vasodilation, induced by different stimuli, is not entirely known. Our aim was to investigate whether the potent vasodilator agent, acetazolamide (AZ), inhibits the neurovascular coupling, which also requires vasodilation. Therefore, visually evoked flow parameters were examined by transcranial Doppler in ten healthy subjects before and after AZ administration. Pulsatility index and peak systolic flow velocity changes, evoked by visual stimulus, were recorded in the posterior cerebral arteries before and after intravenous administration of 15 mg/kg AZ. Repeated-measures ANOVA did not show significant group main effect between the visually evoked relative flow velocity time courses before and after AZ provocation (P=0.43). Visual stimulation induced significant increase of relative flow velocity and decrease of pulsatility index not only before but also at the maximal effect of AZ. These results suggest that maximal cerebral vasodilation cannot be determined by the clinically accepted dose of AZ (15 mg/kg) and prove that neurovascular coupling remains preserved despite AZ-induced vasodilation. Our observation indicates independent regulation of vasodilation during neurovascular coupling, allowing the adaptation of cerebral blood flow according to neuronal activity even if other processes require significant vasodilation.

Correlations between the atherosclerotic changes of femoral, carotid and coronary arteries: a post mortem study.

OBJECTIVE: To compare the severity of atherosclerosis in the carotid, coronary and femoral arteries in autopsy findings of stroke patients. METHODS AND RESULTS: 40 patients (age: 75.2 (12.3) years, 21 men, 19 women) were investigated, who died of ischemic stroke. Carotid, femoral and coronary arteries were removed and cut into slices. Atherosclerotic changes were scored and compared. The severity of atherosclerotic changes of the common carotid artery did not correlate with any other arteries. Atherosclerotic parameters of the internal carotid artery correlated with those of the deep femoral and common femoral arteries (r=0.457-0.459; P=0.022-0.028 respectively). We found significant correlations between the deep femoral artery and left anterior descendent coronary arteries (r=0.513; P=0.012). External carotid artery correlated with both the left anterior descendent coronary and deep femoral arteries (r=0.458-0.473 and P=0.028-0.017 respectively). CONCLUSIONS: The severity of atherosclerosis in the external carotid arteries and/or the femoral arteries showed a stronger correlation with the atherosclerosis in the coronaries than that of the common carotid arteries.

Visually evoked cerebral vasomotor response in smoking and nonsmoking young adults, investigated by functional transcranial Doppler.

Smoking has been known to cause endothelial dysfunction and is an important risk factor for ischemic stroke. In our study we investigated whether chronic cigarette smoking affects the cerebral blood flow velocity response to a physiological, visual stimulus. By using a visual cortex stimulation paradigm, the flow velocity response in the posterior cerebral arteries (PCA) was measured bilaterally, in 32 young healthy adults (16 smokers, 16 nonsmokers). The stimulation protocol consisted of 10 cycles with a resting phase of 20 s and a stimulating phase of 40 s for each cycle. Besides functional transcranial Doppler (TCD), laboratory tests and measurement of intima-media-thickness (IMT) were also performed. Repeated-measure analysis of variance (ANOVA) was used to detect differences in visually evoked relative flow velocity time courses between smokers and nonsmokers. Repeated-measure ANOVA revealed marked difference in the peak systolic flow velocity time courses between smokers and nonsmokers (p< .001). Maximum percent change of visually evoked flow velocity after visual stimulation was 19+/-4% and 30+/-3% in smokers and nonsmokers, respectively (p< .0001). IMT values did not indicate atherosclerosis in young smokers. Infectious disease and hyperlipidemia were also ruled out by measurement of sensitive C-reactive protein and serum lipids. This is the first functional TCD study demonstrating impaired visually evoked flow velocity response caused by chronic cigarette smoking in otherwise healthy, young subjects. The impaired cerebral vasodilatory mechanism together with atherosclerosis may influence stroke occurrence and outcome in chronic smokers.

Severity of carotid atherosclerosis unrelated to Chlamydia pneumoniae infection in acute ischemic stroke patients: a clinicopathological study.

BACKGROUND: Both clinical and pathological alterations of the carotid arteries were correlated with Chlamydia pneumoniae infection in 67 acute ischemic stroke patients with severe neurological symptoms. METHODS: In the clinical study, intima-media thickness (IMT) of the common carotid arteries was determined in vivo by B-mode ultrasound measurement and C. pneumoniae-specific IgG and IgA responses were detected. In the pathological study, the absolute wall thickness of the common, internal and external carotid arteries was measured postmortem in specimens obtained at the autopsy of patients who died due to complications of acute stroke. In the atherosclerotic plaques of the autopsy specimens, C. pneumoniae genomic DNA was detected by polymerase chain reaction amplification. RESULTS: The Spearman's rho correlation coefficient of IMT with the average wall thickness of the common, internal and external carotid arteries was 0.51 (p = 0.002), 0.34 (p = 0.052) and 0.58 (p < 0.001), respectively. Anti-C. pneumoniae IgG and IgA antibodies were detected in 43 (73%) and 29 (49%) patients, but neither antibody marker correlated with IMT (median: 0.91 mm in IgG positives vs. 0.90 mm in IgG negatives, p = 0.86; 0.88 mm in IgA positives vs. 0.90 mm in IgA negatives, p = 0.53). The presence of C. pneumoniae DNA was detected in the carotid plaques of 21 (54%) of the 39 tested patients, independently of either IMT values or the average wall thickness of all carotid arteries. CONCLUSIONS: In acute ischemic stroke patients, C. pneumoniae infection was frequently detected in the arteriosclerotic plaques of the carotid arteries but it did not correlate with the severity of carotid arteriosclerosis.

Calcium distribution in the vessel wall and intima-media thickness of the human carotid arteries.

Increased common carotid artery (CCA) intima-media thickness (IMT) measured by B-mode ultrasound is an early marker of the atherosclerotic process. Arterial calcification is not clearly understood. Using the particle-induced X-ray emission (PIXE) method, we have looked for the location in the artery wall where calcium accumulated in the early phase of atherosclerosis. Twelve segments of CCAs of deceased stroke patients were investigated. In-vivo, carotid duplex ultrasound was performed with bilateral CCA IMT measurement at plaque-free sections. During autopsy, segments of carotid arteries were collected and filled under pressure with a stained histologic embedding material. The frozen arteries were cut into 60-microm-thick slices. Calcium distribution maps from the segments of arteries were determined by PIXE method. IMT measured by ultrasound and calcium distribution maps measured by PIXE were compared. In our cross-sectional study, using the PIXE analysis and ultrasound images, we could demonstrate early calcium accumulation in the media layer. Our results have also shown a significant relationship between calcium content of distributional maps measured by PIXE analysis and corresponding IMT on B-mode ultrasound images of human CCAs.

Activation-flow coupling differentiates between vascular and Alzheimer type of dementia.

The activation-flow coupling describes a mechanism, which adapts local cerebral blood flow in accordance with the underlying neuronal activity. It was suggested that the mechanism helps in differentiation between Alzheimer and vascular type of dementia. We combined EEG and Doppler techniques and assessed integrity of the activation-flow coupling in the occipital cortex utilizing a visual stimulation task. Alzheimer patients (MMSE: 18+/-8 points, DemTect 5+/-4 points) without signs of vascular lesions on a MRI scan and vascular demented patients (MMSE: 20+/-6 points, DemTect 6+/-3 points; MRI Fazekas score 7+/-3 points) were compared with data from an age-matched control group. Evoked flow velocity responses in the posterior cerebral artery were analysed according to a control system model specifying the parameters gain, attenuation, natural frequency and rate time. Evoked potentials were analysed for the N(75)-P(100) amplitude difference. Vascular demented patients exhibited a significant decreased gain parameter and increased attenuation parameter indicating severe cerebrovascular dysfunction. Also, the potential amplitudes were significantly decreased indicating neuronal damage due to the vascular disease process. Alzheimer patients did not differ in parameters as compared to the control group supporting other reports of intact occipital function at this stage of disease. Simultaneous assessment of electrical as well as vascular integrity might help in differentiating the most frequent forms of dementia.