89 research outputs found

    Nitrate reduction in Haloferax alexandrinus: the case of assimilatory nitrate reductase

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    Haloferax alexandrinus Strain TM JCM 10717T = IFO 16590T is an extreme halophilic archaeon able to produce significant amounts of canthaxanthin. Its genome sequence has been analysed in this work using bioinformatics tools available at Expasy in order to look for genes encoding nitrate reductase-like proteins: respiratory nitrate reductase (Nar) and/or assimilatory nitrate reductase (Nas). The ability of the cells to reduce nitrate under aerobic conditions was tested. The enzyme in charge of nitrate reduction under aerobic conditions (Nas) has been purified and characterised. It is a monomeric enzyme (72 ± 1.8 kDa) that requires high salt concentration for stability and activity. The optimum pH value for activity was 9.5. Effectiveness of different substrates, electron donors, cofactors and inhibitors was also reported. High nitrite concentrations were detected within the culture media during aerobic/microaerobic cells growth. The main conclusion from the results is that this haloarchaeon reduces nitrate aerobically thanks to Nas and may induce denitrification under anaerobic/microaerobic conditions using nitrate as electron acceptor. The study sheds light on the role played by haloarchaea in the biogeochemical cycle of nitrogen, paying special attention to nitrate reduction processes. Besides, it provides useful information for future attempts on microecological and biotechnological implications of haloarchaeal nitrate reductases.This work was funded by research grant from the MINECO Spain (CTM2013-43147-R) and by funds from the Department of Biology, Faculty of Science, Anadolu University (Turkey)

    Mean-shift and sparse sampling based SMC-PHD filtering for audio informed visual speaker tracking

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    The probability hypothesis density (PHD) filter based on sequential Monte Carlo (SMC) approximation (also known as SMC-PHD filter) has proven to be a promising algorithm for multi-speaker tracking. However, it has a heavy computational cost as surviving, spawned and born particles need to be distributed in each frame to model the state of the speakers and to estimate jointly the variable number of speakers with their states. In particular, the computational cost is mostly caused by the born particles as they need to be propagated over the entire image in every frame to detect the new speaker presence in the view of the visual tracker. In this paper, we propose to use audio data to improve the visual SMC-PHD (VSMC-PHD) filter by using the direction of arrival (DOA) angles of the audio sources to determine when to propagate the born particles and re-allocate the surviving and spawned particles. The tracking accuracy of the AV-SMC-PHD algorithm is further improved by using a modified mean-shift algorithm to search and climb density gradients iteratively to find the peak of the probability distribution, and the extra computational complexity introduced by mean-shift is controlled with a sparse sampling technique. These improved algorithms, named as AVMS-SMCPHD and sparse-AVMS-SMC-PHD respectively, are compared systematically with AV-SMC-PHD and V-SMC-PHD based on the AV16.3, AMI and CLEAR datasets

    Secondary prevention of coronary heart disease in elderly population of Turkey: A subgroup analysis of ELDERTURK study

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    Background: Secondary prevention plays an important role after acute coronary event due to high risk of adverse events in elderly. In present study we aimed to evaluate the lifestyle, management of risk factors and medical treatment for secondary protection in elderly patients with known coronary heart disease (CHD). Methods: ELDERTURK is a non-interventional, multi-centered, observational study, which included total of 5694 elderly patients ( > 65 years) from 50 centers in Turkey. In this study elderly patients from the ELDERTURK population with known CHD were evaluated for cardiovascular risk factors, comor- bidities and medication usage. Results: A total of 2976 (52.3% of study) out of 5694 patients included in the ELDERTURK study were evaluated. All had known CHD with a mean age of 73.4 ± 6.2 years and 60.3% were male. 13.0% of patients were smokers, 42.4% were overweight and 21.1% were obese. Only 23.6% of patients reported to do regular exercise, 73.4% had history of hypertension, 47.4% had dyslipidemia and 33.9% had diabetes mellitus. The rate of patients with systolic blood pressure > 140 mmHg were 31.1% and only 13.9% of patients had a recommended ≤ 70 mg/dL level of low-density lipoprotein cholesterol. Anti- platelet, statin, beta-blocker and angiotensin-converting enzyme inhibitor/angiotensin receptor blocker usage was limited to 27.3%. Conclusions: The ELDERTURK study shows that many patients with CHD have a high prevalence of modifiable risk factors and unhealthy lifestyle. Apart from this, many patients are not receiving thera- peutic intervention and as a consequence most were not achieving the recommended goals.   

    Lymphocyte-to-monocyte ratio is a valuable marker to predict prostate cancer in patients with prostate specific antigen between 4 and 10 ng/dl

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    Objective: To evaluate the diagnostic value of serum inflammation markers derived from complete blood count in diagnosis of prostate cancer (PCa). Methods: We retrospectively analyzed the data of 621 patients who underwent prostate biopsy between March 2013 and April 2018. Age, prostate specific antigen (PSA), free PSA, platelet count, neutrophil count, lymphocyte count, monocyte count, prostate volume (PV) and pathology result of the patients were recorded. Patients were grouped as benign prostatic hyperplasia (BPH), prostatitis and PCa. Patients were also grouped according to PSA values, as PSA 10 ng/dl. Results: The mean lymphocyte-to-monocyte ratio (LMR) value of the patients with PCa was significantly lower in the entire cohort (p = 0.047). In the PSA 4-10 ng/dl range, LMR value wassignificantly lower in patients with PCa than those with BPH or prostatitis (p = 0.012). In this PSA range, free/total PSA ratio and LMR were significant factors to predict PCa. The cut-off values of LMR, free/total PSA were 3.05 and 0.15 respectively. The sensitivities, spesificities, positive predictive values (PPV) and negative predictive values using LMR cut-off, free/total PSA cut-off and their combination were assessed. Specificity and PPV of the combination group were higher (97.2%, 83.3% respectively) compared to free/total PSA cut-off group (91.6%, 76.6%) and LMR cut-off group (67.8%, 43.7%). Conclusions: LMR is a useful tool at detecting PCa especially in patients with PSA value between 4 and 10 ng/dl. The combination of free/total PSA ratio and LMR improves the diagnostic accuracy more than the use of free/total PSA ratio alone

    A Portable Smartphone-Based Platform with an Offline Image Processing Tool for Rapid Paper-Based Colorimetric Detection of Glucose in Artificial Saliva

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    Paper-based sensors have great potential for use in a variety of areas, from environmental monitoring to clinical and pointof-care testings. Here, a microfluidic paper-based analytical device (µPAD) was integrated with a smartphone app capable of offline (without internet access) image processing and analysis for rapid colorimetric detection of glucose. A self-inking stamp was used to form hydrophobic channels on a piece of paper-towel due to its superior water absorption efficiency. As demonstrated, the developed sensor was employed for colorimetric detection of glucose in artificial saliva in the linear scope of 0-1 mM with a calculated detection limit of 29.65 µM. In addition, experimental results show that quantitative analysis of glucose with the proposed smartphone platform could be completed in less than one minute. The app developed for the smartphone platform is capable of extracting the color changing area with an embedded image processing tool which could address the problem of color uniformity in detection zones of µPAD. The total cost of a µPAD is less than $0.2. By integrating µPAD with a smartphone and user-friendly app together, the proposed smartphone-based platform could be used for the quantitative analysis of glucose with advantages such as portability, simple operation, rapid response, ultra-low cost, field-deployable, selectivity and sensitivity. The results show that the integrated platform has great potential to be used for non-invasive measurement of glucose in body fluids like a tear, sweat and saliva

    Reproductive toxicity after levetiracetam administration in male rats: Evidence for role of hormonal status and oxidative stress.

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    Levetiracetam (LEV) is an antiepileptic drug commonly used in the treatment of epilepsy because of its excellent safety profile in all age groups. It is remarkable that there are no studies evaluating the toxic effects of this drug on the male reproductive system, as it is commonly used in male patients of reproductive age. From this point of view, our aim was to evaluate the possible toxic effects of LEV on the male reproductive system. Therefore, LEV was administered to male rats orally at 50, 150, and 300 mg/kg for 70 consecutive days. At the end of this period, alterations to body and organ weights were calculated, and sperm concentration, motility, and morphology were investigated by a computer-assisted sperm analysis system. Sperm DNA damage was determined by comet assay and histopathological examination of the testes was carried out. Serum testosterone, follicle-stimulating hormone (FSH), and luteinizing hormone (LH) levels were measured by ELISAs to determine the effects of hormonal status, while glutathione, superoxide dismutase, catalase, and malondialdehyde levels in the testes were measured by colorimetric assay kits to determine the role of oxidative status in potential toxicity. According to the results, sperm quality was decreased by LEV treatment in a dose-dependent manner. LEV induced significant DNA damage in the 150 and 300 mg/kg LEV-administered groups. Histopathology of the testes showed that LEV resulted in testicular injury in the 300 mg/kg LEV-administered group. Serum testosterone, FSH, and LH levels were significantly decreased in the 300 mg/kg LEV-administered group. Glutathione, superoxide dismutase, and catalase levels were significantly decreased in all experimental groups while malondialdehyde levels were significantly increased in 150 and 300 mg/kg LEV-administered groups. According to these results, it was determined that LEV administration decreased sperm quality and it was alleged that hormonal alteration and oxidative stress are potential contributors to reproductive toxicity

    Coupling and power transfer efficiency enhancement of modular and array of planar coils using in-plane ring-shaped inner ferrites for inductive heating applications

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    We propose and demonstrate a highly effective method of enhancing coupling and power transfer efficiency in inductive heating systems composed of planar coils. The proposed method is based on locating ring-shaped ferrites in the inner side of the coils in the same plane. Measurement results of simple inductive heating systems constructed with either a single or a pair of conventional circular coils show that, with the in-plane inner ferrites, the total dissipated power of the system is increased by over 65%. Also, with three-dimensional full electromagnetic solutions, it is found that power transfer efficiency of the system is increased up to 92% with the inner ferrite placement. The proposed method is promising to be used for efficiency enhancement in inductive heating applications, especially in all-surface induction hobs.Published versio

    Wireless Metal Detection and Surface Coverage Sensing for All-Surface Induction Heating

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    All-surface induction heating systems, typically comprising small-area coils, face a major challenge in detecting the presence of a metallic vessel and identifying its partial surface coverage over the coils to determine which of the coils to power up. The difficulty arises due to the fact that the user can heat vessels made of a wide variety of metals (and their alloys). To address this problem, we propose and demonstrate a new wireless detection methodology that allows for detecting the presence of metallic vessels together with uniquely sensing their surface coverages while also identifying their effective material type in all-surface induction heating systems. The proposed method is based on telemetrically measuring simultaneously inductance and resistance of the induction coil coupled with the vessel in the heating system. Here, variations in the inductance and resistance values for an all-surface heating coil loaded by vessels (made of stainless steel and aluminum) at different positions were systematically investigated at different frequencies. Results show that, independent of the metal material type, unique identification of the surface coverage is possible at all freqeuncies. Additionally, using the magnitude and phase information extracted from the coupled coil impedance, unique identification of the vessel effective material is also achievable, this time independent of its surface coverage

    Audio constrained particle filter based visual tracking

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    We present a robust and efficient audio-visual (AV) approach to speaker tracking in a room environment. A challenging problem with visual tracking is to deal with occlusions (caused by the limited field of view of cameras or by other speakers). Another challenge is associated with the particle filtering (PF) algorithm, commonly used for visual tracking, which requires a large number of particles to ensure the distribution is well modelled. In this paper, we propose a new method of fusing audio into the PF based visual tracking. We use the direction of arrival angles (DOAs) of the audio sources to reshape the typical Gaussian noise distribution of particles in the propagation step and to weight the observation model in the measurement step. Experiments on AV16.3 datasets show the advantage of our proposed method over the baseline PF method for tracking occluded speakers with a significantly reduced number of particles. © 2013 IEEE
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