3,412 research outputs found

    Detection of Nitro-aromatic Compound in Soil and Sand using Time Gated Raman Spectroscopy

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    Laser based time-gated Raman Spectroscopy experiments for detection and identification of nitro-aromatic sample which premixed with soil and sand in different concentrations are conducted. A back-scattered stand-off Raman spectroscopy set-up using a frequency double Nd:YAG pulsed laser (532 nm, 8 ns, 10 Hz) was employed to evaluate samples made up of standard nitro- aromatic compounds, p-nitro Benzoic acid (PNBA) premixed with soil and sand at different concentrations. A sensitive ICCD detector was used to capture the weak Raman signals buried in high background noise at optimised experiments parameters like laser pulse energy, ICCD gate width, background subtraction, number of laser pulses averaging etc. p- nitro benzoic acid up to 5 per cent (v/v) concentration in sand with appreciable signal to noise ratio has been detected. This feasibility study also becomes relevant to evaluate the remnants for post-blast detection of explosives in terrorist attack as most of the explosives used in such attacks contain nitro-aromatic based high energetic explosives

    Deep Reinforcement Learning Based Secure Transmission for UAV-Assisted Mobile Edge Computing

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    The increasing computational demand for real-time mobile applications has led to the development of mobile edge computing (MEC), with support from unmanned aerial vehicles (UAVs), as a promising paradigm for constructing high-throughput line-of-sight links for ground users and pushing computational resources to network edges. Users can reduce processing latency and the load on their local computers by delegating tasks to the UAV in its role as an edge server. The coverage capacity of a single UAV is, however, very limited. Moreover, it will be easy to intercept the data that is transferred to the unmanned aerial vehicle. Thus, for UAV-assisted mobile edge computing, we proposed a transmission technique based on multi-agent deep reinforcement learning in this study. The recommended approach to maximize UAV deployment first applies the particle swarm optimization algorithm. Then, deep reinforcement learning is utilized to optimize the secure offloading to maximize the system utility and minimize the quantity of information eavesdropping, taking into consideration different user task types with diverse preferences for processing time and residual energy of computing equipment. The results of the simulation demonstrate that, in comparison to the single-agent strategy and the benchmark, the multi-agent approach can optimize offloading more successfully and produce higher system utility

    High resolution CT (HRCT) in miliary tuberculosis (MTB) of the lung: correlation with pulmonary function tests & gas exchange parameters in North Indian patients

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    Background & Objective: High resolution computed tomography (HRCT) scans are known to be helpful in early diagnosis and management of patients with miliary tuberculosis (MTB). We made an attempt in this study to identify patterns of pulmonary MTB on HRCT and to correlate the HRCT disease extent with pulmonary function tests (PFT) and gas exchange analysis (GEA). Methods: A total of 16 non-HIV patients with MTB underwent HRCT of the chest, PFT and GEA. All the investigations in these patients were completed within 20 days of presentation. Evidence of TB was diagnosed by biopsy from lymph nodes (3/16), organ biopsy [skin, liver, bone marrow and lung (transbronchial) (6/16)]. In one patient fundoscopy revealed choroid tubercles. In 6 patients, diagnosis was confirmed by clinical/radiological improvement following anti-tuberculosis therapy. Radiological patterns of involvement on HRCT of the lungs were studied and disease extent was estimated in each case by consensus between two radiologists using specially devised visual scoring system. Disease extent was correlated with PFT and GEA. Spearman rank correlation was used for statistical analysis. Results: Findings on HRCT in MTB included miliary nodularity (16/16), alveolar lesions such as ground glass attenuation and/or consolidation (5/16), lymphadenopathy (8/16), peribronchovascular interstitial thickening (1/16), emphysema (1/16), pleural pathology (2/16), and pericardial effusion (2/16). A significant correlation was noted between disease extent score and forced vital capacity (FVC) (r = −0.76; P=0.003), forced expiratory volume in one second (FEV1)(r = −0.74; P = 0.005), total lung capacity (TLC) (r = −0.66; P = 0.037), oxygen saturation in arterial blood (SaO2) (r = −0.69, P = 0.01), diffusion capacity of the lung (DLco) (r = −0.8; P = 0.02). Interpretation & Conclusion: Our findings showed that HRCT reliably diagnosed MTB, and thus could help in predicting derangement of pulmonary function tests and GEA in these patients

    Ovine pulmonary adenocarcinoma (OPA) in sheep: an update on epidemiology, pathogenesis and diagnosis

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    Ovine pulmonary adenocarcinoma (OPA) is a spontaneous lung tumor in sheep caused by Jaagsiekte sheep retrovirus (JSRV) belonging to the Retroviridae. The primary aim of this review work is to give brief insights into the epidemiological aspects of OPA based on a meta-analysis of available research work. This review article also discussed pathogenesis, diagnostic tests and control strategies available for OPA in Sheep. This will help in developing future strategies for disease-free status in India. This disease is endemic in Europe, Africa, Asia, and American continents, causing significant economic losses due to chronic respiratory illness and persistent infections in flocks. The virus is unique among retroviruses with selective affinity to lungs and is the only virus known to cause spontaneous lung tumors in sheep. The incubation time ranges for sheep with naturally occurring OPA ranged from one to four years. There are two pathological forms of the disease: classical and atypical. At an early stage, OPA is difficult to detect in sheep due to a lack of preclinical diagnostic methods, as JSRV is poorly immunogenic and doesn't induce an immune response. PCR, histopathology, and immunohistochemistry are recommended methods for OIE diagnosis. To become a JSRV-free country, mandatory surveillance, detection, and removal of positive animals are required, as OPA is difficult to control due to a lack of vaccines and preclinical diagnostic tests. Due to its similar histological and molecular pathogenesis to that of human lung cancer, OPA is considered an ideal large animal model of human lung adenocarcinoma

    Defects in Human Methionine Synthase in cblG Patients

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    Inborn errors resulting in isolated functional methionine synthase deficiency fall into two complementation groups, cblG and cblE. Using biochemical approaches we demonstrate that one cblG patient has greatly reduced levels of methionine synthase while in another, the enzyme is specifically impaired in the reductive activation cycle. The biochemical data suggested that low levels of methionine synthase activity in the first patient may result from mutations in the catalytic domains of the enzyme, reduced transcription, or generation of unstable message or protein. Using Northern analysis, we demonstrate that the molecular basis for the biochemical phenotype in this patient is associated with greatly diminished steady-state levels of methionine synthase mRNA. The biochemical data on the second patient cell line implicated mutations specific to reductive activation, a function that is housed in the C-terminal AdoMet-binding domain and the intermediate B12-binding domain, in the highly homologous bacterial enzyme. We have detected two mutations in a compound heterozygous state, one that results in conversion of a conserved proline (1173) to a leucine residue and the other a deletion of an isoleucine residue (881). The crystal structure of the C-terminal domain of the Escherichia coli MS predicts that the Pro to Leu mutation could disrupt activation since it is embedded in a sequence that makes direct contacts with the bound AdoMet. Deletion of isoleucine in the B12-binding domain would result in shortening of a β-sheet. Our data provide the first evidence for mutations in the methionine synthase gene being culpable for the cblG phenotype. In addition, they suggest directly that mutations in methionine synthase can lead to elevated homocysteine, implicated both in neural tube defects and in cardiovascular disease

    Congestion Aware WSN-IoT-Application Layer Protocols for Healthcare Services

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    In the healthcare industry, WSN-IoT networks can be used to gather patient data for statistical purposes. IoT-based application-level protocols do not take into account these facts while forwarding the data to the gateway or server, which may degrade the network performance if the data was collected from a patient with ordinary/critical health issues and the route was busy or congested. In this paper, we'll look at the performance of two application layer protocols (i.e. CoAP and MQTT) within the constraints of a scalable network by integrating a congestion-aware scheme with them

    Coronary microvascular ischemia in hypertrophic cardiomyopathy - a pixel-wise quantitative cardiovascular magnetic resonance perfusion study.

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    BACKGROUND: Microvascular dysfunction in HCM has been associated with adverse clinical outcomes. Advances in quantitative cardiovascular magnetic resonance (CMR) perfusion imaging now allow myocardial blood flow to be quantified at the pixel level. We applied these techniques to investigate the spectrum of microvascular dysfunction in hypertrophic cardiomyopathy (HCM) and to explore its relationship with fibrosis and wall thickness. METHODS: CMR perfusion imaging was undertaken during adenosine-induced hyperemia and again at rest in 35 patients together with late gadolinium enhancement (LGE) imaging. Myocardial blood flow (MBF) was quantified on a pixel-by-pixel basis from CMR perfusion images using a Fermi-constrained deconvolution algorithm. Regions-of-interest (ROI) in hypoperfused and hyperemic myocardium were identified from the MBF pixel maps. The myocardium was also divided into 16 AHA segments. RESULTS: Resting MBF was significantly higher in the endocardium than in the epicardium (mean ± SD: 1.25 ± 0.35 ml/g/min versus 1.20 ± 0.35 ml/g/min, P < 0.001), a pattern that reversed with stress (2.00 ± 0.76 ml/g/min versus 2.36 ± 0.83 ml/g/min, P < 0.001). ROI analysis revealed 11 (31%) patients with stress MBF lower than resting values (1.05 ± 0.39 ml/g/min versus 1.22 ± 0.36 ml/g/min, P = 0.021). There was a significant negative association between hyperemic MBF and wall thickness (β = −0.047 ml/g/min per mm, 95% CI: −0.057 to −0.038, P < 0.001) and a significantly lower probability of fibrosis in a segment with increasing hyperemic MBF (odds ratio per ml/g/min: 0.086, 95% CI: 0.078 to 0.095, P = 0.003). CONCLUSIONS: Pixel-wise quantitative CMR perfusion imaging identifies a subgroup of patients with HCM that have localised severe microvascular dysfunction which may give rise to myocardial ischemia
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