Breakup of Liquid Feedstock in Plasma Spraying

Suspension plasma spray is an emerging technology to produce functional nanostructured coatings at moderate cost. In general, in this technique, the liquid is injected radially into a high-velocity high-temperature plasma flow. After liquid breakup and evaporation, solid particles remain in the field and impact the substrate. Preliminary studies have shown that liquid jet atomization is the primary phenomenon that controls the coating quality. However, due to the complex thermophysical properties of plasma and its intricate flow physics, the breakup processes of liquid jets in plasma crossflows have not been investigated comprehensively yet. In general, the gaseous Reynolds number and the liquid-to-gas density ratio in this process are around 50 and 10,000, respectively, which are far outside the limits commonly observed in engines and wind tunnels. In this regard, detailed features of the breakup phenomena of the liquid jets injected in plasma and air crossflow are provided. Moreover, a case study has been established to analyze the effect of changing the surface tension of the liquid in the plasma spray process. The finite volume scheme is used to solve the incompressible variable-density Navier-Stokes equations. In addition, the volume of fluid (VOF) approach is utilized to track the gas-liquid interfaces. Finally, qualitative results such as instantaneous snapshots and shape of the liquid jet cross-sections, in company with quantitative data like including fracture point location, length of surface waves and size of the droplets have been presented

More evidence for H2O2-mediated oxidative stress in vitiligo-increased epidermal DNA damage / repair.

Nowdays there is a plethora of evidence for H2O2-mediated oxidative stress in the epidermis as well as in the system in patients with vitiligo (for review see (Schallreuter, Bahadoran et al. 2008). Xanthine dehydrogenase / xanthine oxidase (XDH / XO) catalyses the oxidative hydroxylation of hypoxanthine to xanthine followed by xanthine to uric acid, the last two steps in purine degradation pathway. Under oxidative conditions, XDH is converted to XO. The reactions catalysed by this enzyme generate H2O2 and O2 ¿- , yielding in the presence of ROS accumulation, allantoin from uric acid. Therefore XO has been considered a major biologic source of oxygen-derived free radicals in many organs. The presence of XO in the human epidermis has not been shown so far. In this study several techniques were utilised to nail the presence and activity of XO in epidermal melanocytes and keratinocytes. The enzyme is regulated by H2O2 in a concentration dependent manner, where concentrations of 10-6M upregulate activity. Importantly, the results showed that the activity of XO is little affected by H2O2 in the mM range. H2O2-mediated oxidation of tryptophan and methionine residues in the sequence of XO yields only subtle alterations in the enzyme active site. These findings are in agreement with enzyme kinetics in the presence of 10-3M H2O2. Since uric acid is the end product of XO activity and this can be oxidised to allantoin by H2O2, we wanted to know whether allantoin is formed in the epidermis of patients with vitiligo. In order to address this issue, we utilised HPLC/mass spectrometry analysis. Analysis of epidermal cell extracts from suction blister tissue identified the presence of allantoin in patients with acute vitiligo, while this product was absent in healthy controls. In conclusion, our results provide evidence for functioning epidermal XO in the human epidermis which 4 can be a major source for the production of H2O2 contributing to oxidative stress in vitiligo. In addition, this thesis also demonstrates for the first time the presence of XO in melanosomes, and we showed that both 7BH4 and 7-biopterin inhibit XO activity in a concentration dependent manner. Moreover, XO has the potential to bind to 6/7BH4 and 6/7-biopterin from the pterin/tyrosinase inhibitor complex. This discovery adds another receptor independent mechanism for regulation of tyrosinase within the melanocyte similar to ¿/ß-MSH as shown earlier (Moore, Wood et al. 1999; Spencer, Chavan et al. 2005). Since the entire epidermis of patients with vitiligo is under H2O2-mediated oxidative stress, oxidative DNA damage would be highly expected. This thesis shows for the first time that epidermal 8-oxoG levels as well as plasma level of this oxidised DNA base are significantly increased in patients compared to healthy controls. We have shown that epidermal cells from patients with vitiligo respond to oxidative DNA damage via the overexpression of p21 and Gadd45¿ leading to a functioning increased short-patch base-excision repair (BER), while increased apoptosis can be ruled out due to lower caspase 3 and cytochrome c response compared to healthy controls. Our results show that patients develop effective DNA repair machinery via hOgg1, APE1 and DNA polymeraseß. Taking into consideration that these patients do not have an increased prevalence for solar-induced skin cancers, our data suggest that BER is a major player in the hierarchy to combat H2O2-mediated oxidative stress preventing ROS-induced tumourigenesis in the epidermis of these patients

cerebellar infarction in a 9 years old child presenting with fever and ataxia

Background: Cerebellar acute ischemic stroke (AIS) can be a complication of minor head trauma, vertebral artery dissection, vasospasm or systemic hypoperfusion. Computed Tomography (CT) scan usually is negative few hours after acute infarction. Magnetic resonance imaging (MRI) is superior to CT scan for posterior fossa lesions and also in acute phase of cerebellar stroke specially in children. Case summary: The patient was a 9 years Old girl presenting with sudden onset of headache and recurrent vomiting, ataxia and history of 3 consecutive days of fever and malaise. In the report of MRI there were abnormal low T1 and high T2 signal intensity in left cerebellar hemisphere involving superior and middle cerebellar peduncles. After 4 days of admission, the patient became drowsy, symptoms progressed and transfered to the pediatric intensive care unit (PICU). The patient underwent hemispherectomy surgery of the left cerebellar hemisphere because of acute obstructive hydrocephaly. After 5 months of occupational therapy the force of her extremities were normal and the ataxia completely disappeared. Conclusion: Childhood acute ischemic stroke although rare can happen with cerebellar involvement. Because in our patient the first brain CT scan was nearly normal and a false negative rate for initial computed tomography (CT) scanning of 60-80 percent also contributes to missed and delayed diagnosis of childhood AIS, we conclude that for every child presenting with acute ataxia without identified cause in addition to CT scan, MRI also being ordered and from the beginning beside other causes, stroke be contemplated as a cause of ataxia

Symmetric Duality in Mathematical Programming

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Cerebellar infarction in a 9 year old child presenting with fever and ataxia: A case report

Cerebellar acute ischemic stroke (CAIS) can be a complication of minor head trauma, vertebral artery dissection, vasospasm or systemic hypoperfusion. CT scan usually is negative few hours after acute infarction. Magnetic resonance imaging (MRI) is superior to CT scan for posterior fossa lesions and also in acute phase of cerebellar stroke especially in children. Here we report a 9-year-old girl referred to the Pediatric Emergency Room, Moosavi Hospital, Zanjan, Iran in January 2017 presenting with sudden onset of headache and recurrent vomiting, ataxia, and history of 3 consecutive days of fever and malaise. In the report of MRI, there were abnormal low T1 and high T2 signal intensity in left cerebellar hemisphere involving superior and middle cerebellar peduncles. After 4 days of admission, the patient became drowsy, symptoms progressed and transferred to the pediatric intensive care unit (PICU). The patient underwent hemispherectomy surgery of the left cerebellar hemisphere because of acute obstructive hydrocephaly. After 5 months of occupational therapy, the force of her extremities was normal and the ataxia completely disappeared. Childhood acute ischemic stroke although rare can happen with cerebellar involvement. Because in our patient the first brain CT scan was nearly normal and a false negative rate for initial computed tomography (CT) scanning of 60-80 also contributes to missed and delayed diagnosis of childhood AIS, for every child presenting with acute ataxia without identified cause in addition to CT scan, MRI also being ordered and from the beginning besides other causes, stroke be contemplated as a cause of ataxia. © 2019, Iranian Child Neurology Society. All rights reserved

Left ventricle wall motion quantification from echocardiographic images by non-rigid image registration

Purpose: The aim of this study is to evaluate the efficiency of applying a new non-rigid image registration method on two-dimensional echocardiographic images for computing the left ventricle (LV) myocardial motion field over a cardiac cycle. Methods: The key feature of our method is to register all images in the sequence to a reference image (end-diastole image) using a hierarchical transformation model, which is a combination of an affine transformation for modeling the global LV motion and a free-form deformation (FFD) transformation based on B-splines for modeling the local LV deformation. Registration is done by minimizing a cost function associated with the image similarity based on a global pixel-based matching and the smoothness of transformation. The algorithm uses a fast and robust optimization strategy using a multiresolution approach for the estimation of parameters of the deformation model. The proposed algorithm is evaluated for calculating the displacement curves of two expert-identified anatomical landmarks in apical views of the LV for 10 healthy volunteers and 14 subjects with pathology. The proposed algorithm is also evaluated for classifying the regional LV wall motion abnormality using the calculation of the strain value at the end of systole in 288 segments as scored by two consensual experienced echocardiographers in a three-point scale: 1: normokinesia, 2: hypokinesia, and 3: akinesia. Moreover, we compared the results of the proposed registration algorithm to those previously obtained using the other image registration methods. Results: Regarding to the reference two experienced echocardiographers, the results demonstrate the proposed algorithm more accurately estimates the displacement curve of the two anatomical landmarks in apical views than the other registration methods in all data set. Moreover, the p values of the t test for the strain value of each segment at the end of systole measured by the proposed algorithm show higher differences than the other registration method. These differences are between each pair of scores in all segments and in three segments of septum independently. Conclusions: The clinical results show that the proposed algorithm can improve both the calculation of the displacement curve of every point of LV during a cardiac cycle and the classification of regional LV wall motion abnormality. Therefore, this diagnostic system can be used as a useful tool for clinical evaluation of the regional LV function. © 2012 CARS

Epidemiological aspects and clinical outcome of patients with rhinocerebral zygomycosis: A survey in a referral hospital in Iran

Introduction: No comprehensive reports have been published on epidemiological status of Rhinocerebral zygomycosis infections and its outcome in our population, Hence, the current study came to address epidemiological characteristics as well as clinical outcome of patients with Rhinocerebral zygomycosis infection referred to a referral hospital in Iran. Methods: This retrospective study was performed at the Rasoul-e-Akram hospital, an 800-bed tertiary care teaching hospital in Tehran, Iran. The pathology recorded charts were reviewed to identify all cases of Rhinocerebral zygomycosis from patients admitted between April 2007 and March 2014. A diagnosis of Rhinocerebral zygomycosis was based on histopathological assessments. Results: Sixty four patients with Rhinocerebral zygomycosis were assessed. The mean age of the patients was 46.07 ± 22.59 years and 51.6 were female. Among those, 67.2 were diabetic, 26.6 were hypertensive and 29.7 had history of cancer. Different sinuses were infected in 73.4 of the patients. Out of all the patients 26.6 underwent surgical procedures and 17.2 were controlled medically. Extensive debridement was carried out in 40.6. Neutropenia ( 14 days) was found in 60.9. According to the Multivariable logistic regression analysis, the main predictors of in-hospital mortality included female gender, advanced age, the presence of sinus infection, and neutropenia, while higher dosages of amphotericin administered had a protective role in preventing early mortality. In a similar Multivariate model, history of cancer could predict prolonged hospital stay, whereas using higher dose of amphotericin could lead to shortening length of hospital stay. Conclusion: There is no difference in demographic characteristics between our patients with Rhinocerebral zygomycosis and other nations. The presence of diabetes mellitus is closely associated with the presence of this infection. Sinus involvement is very common in those with Rhinocerebral zygomycosis leading to high mortality and morbidity. Besides female gender, advanced age, and presence of neutropenia was a major risk factor for increasing early mortality. The use of higher doses of antifungal treatment such as amphotericin can prevent both mortality and prolonged hospital stay. The cancer patients may need longer hospital stay because of needing comprehensive in-hospital treatment. © Vida Bozorgiet al

Instantaneous 3D EEG Signal Analysis Based on Empirical Mode Decomposition and the Hilbert–Huang Transform Applied to Depth of Anaesthesia

Depth of anaesthesia (DoA) is an important measure for assessing the degree to which the central nervous system of a patient is depressed by a general anaesthetic agent, depending on the potency and concentration with which anaesthesia is administered during surgery. We can monitor the DoA by observing the patient’s electroencephalography (EEG) signals during the surgical procedure. Typically high frequency EEG signals indicates the patient is conscious, while low frequency signals mean the patient is in a general anaesthetic state. If the anaesthetist is able to observe the instantaneous frequency changes of the patient’s EEG signals during surgery this can help to better regulate and monitor DoA, reducing surgical and post-operative risks. This paper describes an approach towards the development of a 3D real-time visualization application which can show the instantaneous frequency and instantaneous amplitude of EEG simultaneously by using empirical mode decomposition (EMD) and the Hilbert–Huang transform (HHT). HHT uses the EMD method to decompose a signal into so-called intrinsic mode functions (IMFs). The Hilbert spectral analysis method is then used to obtain instantaneous frequency data. The HHT provides a new method of analyzing non-stationary and nonlinear time series data. We investigate this approach by analyzing EEG data collected from patients undergoing surgical procedures. The results show that the EEG differences between three distinct surgical stages computed by using sample entropy (SampEn) are consistent with the expected differences between these stages based on the bispectral index (BIS), which has been shown to be quantifiable measure of the effect of anaesthetics on the central nervous system. Also, the proposed filtering approach is more effective compared to the standard filtering method in filtering out signal noise resulting in more consistent results than those provided by the BIS. The proposed approach is therefore able to distinguish between key operational stages related to DoA, which is consistent with the clinical observations. SampEn can also be viewed as a useful index for evaluating and monitoring the DoA of a patient when used in combination with this approach

Prediction of autoimmune connective tissue disease in an at-risk cohort: prognostic value of a novel two-score system for interferon status

Objective: To evaluate clinical, interferon and imaging predictors of progression from ‘At Risk’ to autoimmune connective tissue diseases (AI-CTDs). Methods: A prospective observational study was conducted in At-Risk of AI-CTD (defined as antinuclear antibody (ANA) positive; ≤1 clinical systemic lupus erythematosus (SLE) criterion; symptom duration <12 months and treatment-naïve). Bloods and skin biopsy (non-lesional) were analysed for two interferon-stimulated gene expression scores previously described (IFN-Score-A and IFN-Score-B). Forty-nine healthy controls (HCs) and 114 SLE were used as negative and positive controls. Musculoskeletal ultrasound was performed. Progression was defined by meeting classification criteria for AI-CTDs at 12 months. Results: 118 individuals with 12-month follow-up were included. Of these, 19/118 (16%) progressed to AI-CTD (SLE=14, primary Sjogren’s=5). At baseline, both IFN scores differed among At-Risk, HCs and SLE groups (p<0.001) and both were elevated in At-Risk who progressed to AI-CTD at 12 months versus non-progressors, to a greater extent for IFN-Score-B (fold difference (95% CI) 3.22 (1.74 to 5.95), p<0.001) than IFN-Score-A (2.94 (1.14 to 7.54); p=0.018). Progressors did not have significantly greater baseline clinical characteristics or ultrasound findings. Fold difference between At-Risk and HCs for IFN-Score-A was markedly greater in skin than blood. In multivariable logistic regression, only family history of autoimmune rheumatic disease, OR 8.2 (95% CI 1.58 to 42.53) and IFN-Score-B, 3.79 (1.50–9.58) increased the odds of progression. Conclusion: A two-factor interferon score and family history predict progression from ANA positivity to AI-CTD. These interferon scores may allow stratification of individuals At-Risk of AI-CTD permitting early intervention for disease prevention and avoid irreversible organ damage