1,422 research outputs found

    Simulation of Impedance Measurements at Human Forearm Within 1 KHz to 2 MHz

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    This work presents a simulation analysis of the bioimpedance measurements at human forearm. The Ansysยฎ High Frequency Structure Simulator (HFSS) has been used to analyze the electrical response of a section of human forearm with three domains of di-electric behavior- fat, muscle and artery (blood). The impedance values were calculated as the ratio of the output voltage at the electrodes to the applied known current (1mA). A model was developed and was simulated for impedance values obtained within a frequency range of 1 kHz to 2MHz. The measurements were done at three instances of radial artery diameter. The maximum resistance and reactance values were calculated as 445ฮฉ and 178.5ฮฉ, 356ฮฉ and 138ฮฉ, and 368ฮฉ and 144.3ฮฉ for diameters 2.3mm, 2.35mm, and 2.4mm respectively. The set of impedance values obtained followed Cole-plot trend. The results obtained were found to be in excellent agreement with the Cole theory. The set of values obtained at three different diameters reflected the effect of blood flow on impedance values

    Diagnostic Accuracy of Computed Tomography by Fungal Sinusitis: A Case-control Study

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    Introduction: Recent decades show a considerable increase in fungal infections, hence can lead to fungal sinusitis. Immunosuppression, post organ transplant, diabetes mellitus, and Human Immunodeficiency Virus (HIV) infection have led to a rise in the incidence of fungal infections. Recent advances in nasal endoscopy, Computed Tomography (CT), and Histopathological Examination (HPE) Techniques have led to better detection of fungal aetiology. Aim: To determine the most significant CT findings in fungal sinusitis or combination of findings in comparison to HPE. Materials and Methods: This retrospective case-control study was done at Sri Manakula Vinayagar Medical College and Hospital, Puducherry from January 2017 to December 2020. Total number of patients were 90. Total 50 cases of fungal sinusitis confirmed with histopathological confirmation and available non contrast CT Paranasal Sinus (PNS) images where time interval between CT and Functional Endoscopic Sinus Surgery (FESS) not exceeding ten days were included. The control group had 40 patients with chronic sinusitis with HPE negative results. CT PNS were performed on PHILIPS 16 slice scanner without contrast administration. Data was entered into Microsoft excel and analysed using Statistical Package for the Social Sciences (SPSS) 22.0 version software. Results: Mean age of the cases (fungal sinusitis) were 46.7ยฑ17 years and 39ยฑ13.1 years of controls. Of the total 90 subjects, heterogeneous mucosal thickening was seen in 41 (45.6%), intrasinus hyperattenuation in 36 (40%), bone sclerosis in 44 (48.9%), bone erosion in 36 (40%), sinus expansion in 23 (25.6%) subjects. Fungal sinusitis patients had more proportion of these findings when compared to control group and hence p-value was significant. Conclusion: The CT diagnostic features of the fungal sinusitis are heterogeneous mucosal thickening, intrasinus hyperattenuation, bone sclerosis, bone erosion and sinus expansion which were significant. These findings help to differentiate fungal sinusitis from non fungal sinusitis

    Comparison of the tetrahedron method to smearing methods for the electronic density of states

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    The electronic density of states (DOS) highlights fundamental properties of materials that oftentimes dictate their properties, such as the band gap and Van Hove singularities. In this short note, we discuss how sharp features of the density of states can be obscured by smearing methods (such as the Gaussian and Fermi smearing methods) when calculating the DOS. While the common approach to reach a "converged" density of states of a material is to increase the discrete k-point mesh density, we show that the DOS calculated by smearing methods can appear to converge but not to the correct DOS. Employing the tetrahedron method for Brillouin zone integration resolves key features of the density of states far better than smearing methods

    sCompile: Critical path identification and analysis for smart contracts

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    Ethereum smart contracts are an innovation built on top of the blockchain technology, which provides a platform for automatically executing contracts in an anonymous, distributed, and trusted way. The problem is magnified by the fact that smart contracts, unlike ordinary programs, cannot be patched easily once deployed. It is important for smart contracts to be checked against potential vulnerabilities. In this work, we propose an alternative approach to automatically identify critical program paths (with multiple function calls including inter-contract function calls) in a smart contract, rank the paths according to their criticalness, discard them if they are infeasible or otherwise present them with user friendly warnings for user inspection. We identify paths which involve monetary transaction as critical paths, and prioritize those which potentially violate important properties. For scalability, symbolic execution techniques are only applied to top ranked critical paths. Our approach has been implemented in a tool called sCompile, which has been applied to 36,099 smart contracts. The experiment results show that sCompile is efficient, i.e., 5 seconds on average for one smart contract. Furthermore, we show that many known vulnerabilities can be captured if user inspects as few as 10 program paths generated by sCompile. Lastly, sCompile discovered 224 unknown vulnerabilities with a false positive rate of 15.4% before user inspection.Comment: Accepted by ICFEM 201

    The male fetal biomarker INSL3 reveals substantial hormone exchange between fetuses in early pig gestation

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    The peptide hormone INSL3 is uniquely produced by the fetal testis to promote the transabdominal phase of testicular descent. Because it is fetal sex specific, and is present in only very low amounts in the maternal circulation, INSL3 acts as an ideal biomarker with which to monitor the movement of fetal hormones within the pregnant uterus of a polytocous species, the pig. INSL3 production by the fetal testis begins at around GD30. At GD45 of the ca.114 day gestation, a time at which testicular descent is promoted, INSL3 evidently moves from male to female allantoic compartments, presumably impacting also on the female fetal circulation. At later time-points (GD63, GD92) there is less inter-fetal transfer, although there still appears to be significant INSL3, presumably of male origin, in the plasma of female fetuses. This study thus provides evidence for substantial transfer of a peptide hormone between fetuses, and probably also across the placenta, emphasizing the vulnerability of the fetus to extrinsic hormonal influences within the uterus

    Adapted motivational interviewing to improve the uptake of treatment for glaucoma in Nigeria: study protocol for a randomized controlled trial.

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    BACKGROUND: Glaucoma is a chronic eye disease associated with irreversible visual loss. In Africa, glaucoma patients often present late, with very advanced disease. One-off procedures, such as laser or surgery, are recommended in Africa because of lack of or poor adherence to medical treatment. However, acceptance of surgery is usually extremely low. To prevent blindness, adherence to treatment needs to improve, using acceptable, replicable and cost-effective interventions. After reviewing the literature and interviewing patients in Bauchi (Nigeria) motivational interviewing (MI) was selected as the intervention for this trial, with adaptation for glaucoma (MIG). MI is designed to strengthen personal motivation for, and commitment to a specific goal by eliciting and exploring a person's reasons for change within an atmosphere of acceptance and compassion. The aim of this study is to assess whether MIG increases the uptake of laser or surgery amongst glaucoma patients where this is the recommended treatment. The hypothesis is that MIG increases the uptake of treatment. This will be the first trial of MI in Africa. METHODS: This is a hospital based, single centre, randomized controlled trial of MIG plus an information sheet on glaucoma and its treatment (the latter being "standard care") compared with standard care alone for glaucoma patients where the treatment recommended is surgery or laser.Those eligible for the trial are adults aged 17ย years and above who live within 200ย km of Bauchi with advanced glaucoma where the examining ophthalmologist recommends surgery or laser. After obtaining written informed consent, participants will be randomly allocated to MIG plus standard care, or standard care alone. Motivational interviewing will be delivered in Hausa or English by one of two MIG trained personnel. One hundred and fifty participants will be recruited to each arm. The primary outcome is the proportion of participants undergoing laser or surgery within two months of the date given to re attend for the procedure. MIG quality will be assessed using the validated MI treatment integrity scale. DISCUSSION: Motivational interviewing may be an important tool to increase the acceptance of treatment for glaucoma. The approach is potentially scalable and may be useful for other chronic conditions in Africa. TRIAL REGISTRATION: ISRCTN79330571 (Controlled-Trials.com)

    Genetic influences on disease course and severity, 30 years after a clinically isolated syndrome

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    Multiple sclerosis risk has a well-established polygenic component, yet the genetic contribution to disease course and severity remains unclear and difficult to examine. Accurately measuring disease progression requires long-term study of clinical and radiological outcomes with sufficient follow-up duration to confidently confirm disability accrual and multiple sclerosis phenotypes. In this retrospective study, we explore genetic influences on long-term disease course and severity; in a unique cohort of clinically isolated syndrome patients with homogenous 30-year disease duration, deep clinical phenotyping and advanced MRI metrics. Sixty-one clinically isolated syndrome patients [41 female (67%): 20 male (33%)] underwent clinical and MRI assessment at baseline, 1-, 5-, 10-, 14-, 20- and 30-year follow-up (mean age ยฑ standard deviation: 60.9 ยฑ 6.5 years). After 30 years, 29 patients developed relapsing-remitting multiple sclerosis, 15 developed secondary progressive multiple sclerosis and 17 still had a clinically isolated syndrome. Twenty-seven genes were investigated for associations with clinical outcomes [including disease course and Expanded Disability Status Scale (EDSS)] and brain MRI (including white matter lesions, cortical lesions, and brain tissue volumes) at the 30-year follow-up. Genetic associations with changes in EDSS, relapses, white matter lesions and brain atrophy (third ventricular and medullary measurements) over 30 years were assessed using mixed-effects models. HLA-DRB1*1501-positive (n = 26) patients showed faster white matter lesion accrual [+1.96 lesions/year (0.64-3.29), P = 3.8 ร— 10-3], greater 30-year white matter lesion volumes [+11.60โ€…ml, (5.49-18.29), P = 1.27 ร— 10-3] and higher annualized relapse rates [+0.06 relapses/year (0.005-0.11), P = 0.031] compared with HLA-DRB1*1501-negative patients (n = 35). PVRL2-positive patients (n = 41) had more cortical lesions (+0.83 [0.08-1.66], P = 0.042), faster EDSS worsening [+0.06 points/year (0.02-0.11), P = 0.010], greater 30-year EDSS [+1.72 (0.49-2.93), P = 0.013; multiple sclerosis cases: +2.60 (1.30-3.87), P = 2.02 ร— 10-3], and greater risk of secondary progressive multiple sclerosis [odds ratio (OR) = 12.25 (1.15-23.10), P = 0.031] than PVRL2-negative patients (n = 18). In contrast, IRX1-positive (n = 30) patients had preserved 30-year grey matter fraction [+0.76% (0.28-1.29), P = 8.4 ร— 10-3], lower risk of cortical lesions [OR = 0.22 (0.05-0.99), P = 0.049] and lower 30-year EDSS [-1.35 (-0.87,-3.44), P = 0.026; multiple sclerosis cases: -2.12 (-0.87, -3.44), P = 5.02 ร— 10-3] than IRX1-negative patients (n = 30). In multiple sclerosis cases, IRX1-positive patients also had slower EDSS worsening [-0.07 points/year (-0.01,-0.13), P = 0.015] and lower risk of secondary progressive multiple sclerosis [OR = 0.19 (0.04-0.92), P = 0.042]. These exploratory findings support diverse genetic influences on pathological mechanisms associated with multiple sclerosis disease course. HLA-DRB1*1501 influenced white matter inflammation and relapses, while IRX1 (protective) and PVRL2 (adverse) were associated with grey matter pathology (cortical lesions and atrophy), long-term disability worsening and the risk of developing secondary progressive multiple sclerosis

    Arterial oxygen content is precisely maintained by graded erythrocytotic responses in settings of high/normal serum iron levels, and predicts exercise capacity: an observational study of hypoxaemic patients with pulmonary arteriovenous malformations.

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    Oxygen, haemoglobin and cardiac output are integrated components of oxygen transport: each gram of haemoglobin transports 1.34 mls of oxygen in the blood. Low arterial partial pressure of oxygen (PaO2), and haemoglobin saturation (SaO2), are the indices used in clinical assessments, and usually result from low inspired oxygen concentrations, or alveolar/airways disease. Our objective was to examine low blood oxygen/haemoglobin relationships in chronically compensated states without concurrent hypoxic pulmonary vasoreactivity.165 consecutive unselected patients with pulmonary arteriovenous malformations were studied, in 98 cases, pre/post embolisation treatment. 159 (96%) had hereditary haemorrhagic telangiectasia. Arterial oxygen content was calculated by SaO2 x haemoglobin x 1.34/100.There was wide variation in SaO2 on air (78.5-99, median 95)% but due to secondary erythrocytosis and resultant polycythaemia, SaO2 explained only 0.1% of the variance in arterial oxygen content per unit blood volume. Secondary erythrocytosis was achievable with low iron stores, but only if serum iron was high-normal: Low serum iron levels were associated with reduced haemoglobin per erythrocyte, and overall arterial oxygen content was lower in iron deficient patients (median 16.0 [IQR 14.9, 17.4]mls/dL compared to 18.8 [IQR 17.4, 20.1]mls/dL, p<0.0001). Exercise tolerance appeared unrelated to SaO2 but was significantly worse in patients with lower oxygen content (p<0.0001). A pre-defined athletic group had higher Hb:SaO2 and serum iron:ferritin ratios than non-athletes with normal exercise capacity. PAVM embolisation increased SaO2, but arterial oxygen content was precisely restored by a subsequent fall in haemoglobin: 86 (87.8%) patients reported no change in exercise tolerance at post-embolisation follow-up.Haemoglobin and oxygen measurements in isolation do not indicate the more physiologically relevant oxygen content per unit blood volume. This can be maintained for SaO2 โ‰ฅ78.5%, and resets to the same arterial oxygen content after correction of hypoxaemia. Serum iron concentrations, not ferritin, seem to predict more successful polycythaemic responses

    A Review of CAM for Procedural Pain in Infancy: Part I. Sucrose and Non-nutritive Sucking

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    There is increasing concern regarding the number of painful medical procedures that infants must undergo and the potential risks of alleviating infant pain with conventional pharmacologic agents. This article is Part I of a two-part series that aims to provide an overview of the literature on complementary and alternative (CAM) approaches for pain and distress related to medical procedures among infants up to six weeks of age. The focus of this article is a review of the empirical literature on sucrose with or without non-nutritive sucking (NNS) for procedural pain in infancy. Computerized databases were searched for relevant studies including prior reviews and primary trials. The most robust evidence was found for the analgesic effects of sucrose with or without NNS on minor procedural pain in healthy full-term infants. Despite some methodological weaknesses, the literature to date supports the use of sucrose, NNS and other sweetened solutions for the management of procedural pain in infancy

    Linkage Specific Fucosylation of Alpha-1-Antitrypsin in Liver Cirrhosis and Cancer Patients: Implications for a Biomarker of Hepatocellular Carcinoma

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    We previously reported increased levels of protein-linked fucosylation with the development of liver cancer and identified many of the proteins containing the altered glycan structures. One such protein is alpha-1-antitrypsin (A1AT). To advance these studies, we performed N-linked glycan analysis on the five major isoforms of A1AT and completed a comprehensive study of the glycosylation of A1AT found in healthy controls, patients with hepatitis C- (HCV) induced liver cirrhosis, and in patients infected with HCV with a diagnosis of hepatocellular carcinoma (HCC).Patients with liver cirrhosis and liver cancer had increased levels of triantennary glycan-containing outer arm (alpha-1,3) fucosylation. Increases in core (alpha-1,6) fucosylation were observed only on A1AT from patients with cancer. We performed a lectin fluorophore-linked immunosorbent assay using Aleuria Aurantia lectin (AAL), specific for core and outer arm fucosylation in over 400 patients with liver disease. AAL-reactive A1AT was able to detect HCC with a sensitivity of 70% and a specificity of 86%, which was greater than that observed with the current marker of HCC, alpha-fetoprotein. Glycosylation analysis of the false positives was performed; results indicated that these patients had increases in outer arm fucosylation but not in core fucosylation, suggesting that core fucosylation is cancer specific.This report details the stepwise change in the glycosylation of A1AT with the progression from liver cirrhosis to cancer and identifies core fucosylation on A1AT as an HCC specific modification
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