416 research outputs found

    Multi-Vehicle Speed Estimation Algorithm Based on Real-Time Inter-Frame Tracking Technique

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    Inappropriate vehicle speeding remains a central factor that causes road accidents claiming millions of lives every year. This challenge has raised concerns for vehicle speed estimation as an attempt to promote speed enforcement methods. Traditionally, radar and lidar systems have widely been used for this purpose, despite their several shortfalls: cosine error effects, need for direct line-of-sight, and inability to simultaneously and accurately measure speed from multiple vehicles. The current work proposes an algorithm and a multi-vehicle speed estimation system in a multi-lane road environment to address multi-vehicle speed estimation shortfalls. The proposed solution exploits image processing and computer vision techniques to flag vehicles with inappropriate speeding patterns. A series of experiments showed that the developed system generates more accurate results than those given by the lidar system. In essence, the proposed system can estimate the speed of up to six vehicles concurrently. It can produce an average percentage error of 2.7% relative to the actual speed measured by a speedometer. This error is 5.4% lower than that demonstrated by the lidar system, emphasizing that the proposed system may be a more suitable approach to traffic laws enforcement. Keywords: Computer vision; image processing; inter-frame differencing; vehicle tracking; road acciden

    Intraoperative Organ Motion Models with an Ensemble of Conditional Generative Adversarial Networks

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    In this paper, we describe how a patient-specific, ultrasound-probe-induced prostate motion model can be directly generated from a single preoperative MR image. Our motion model allows for sampling from the conditional distribution of dense displacement fields, is encoded by a generative neural network conditioned on a medical image, and accepts random noise as additional input. The generative network is trained by a minimax optimisation with a second discriminative neural network, tasked to distinguish generated samples from training motion data. In this work, we propose that 1) jointly optimising a third conditioning neural network that pre-processes the input image, can effectively extract patient-specific features for conditioning; and 2) combining multiple generative models trained separately with heuristically pre-disjointed training data sets can adequately mitigate the problem of mode collapse. Trained with diagnostic T2-weighted MR images from 143 real patients and 73,216 3D dense displacement fields from finite element simulations of intraoperative prostate motion due to transrectal ultrasound probe pressure, the proposed models produced physically-plausible patient-specific motion of prostate glands. The ability to capture biomechanically simulated motion was evaluated using two errors representing generalisability and specificity of the model. The median values, calculated from a 10-fold cross-validation, were 2.8+/-0.3 mm and 1.7+/-0.1 mm, respectively. We conclude that the introduced approach demonstrates the feasibility of applying state-of-the-art machine learning algorithms to generate organ motion models from patient images, and shows significant promise for future research.Comment: Accepted to MICCAI 201

    Value of systematic sampling in an mp-MRI targeted prostate biopsy strategy

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    The clinical utility of systematic prostate biopsy in addition to multi-parametric magnetic resonance imagining (mp-MRI) targeted biopsy pathways remains unclear. Despite radiological advancements in mp-MRI and utilisation of international standardised reporting systems (i.e., PI-RADS, LIKERT), undetected clinically significant prostate cancer (csPCa) on imaging persists. This has prevented the widespread adoption of an exclusively targeted biopsy approach. The current evidence on csPCa cancer detection rates in mp-MRI targeted alone and combined with a non-targeted systematic sampling is presented. Arguments for and against routine limited systematic sampling as an adjunct to an mp-MRI targeted biopsy are discussed. Our review will report the clinical utility of a combined sampling strategy on csPCa detection rate. The available evidence suggests that we are yet to reach a stage where non-targeted systematic prostate biopsy can be routinely omitted in mp-MRI targeted prostate biopsy pathways. Research should focus on improving the accuracy of mp-MRI, prostate biopsy techniques, and in identifying those men that will most benefit from a combined prostate biopsy. Such strategies may help future urologists reduce the burden of non-targeted cores in modern mp-MRI prostate biopsy pathways

    Effect of Chilled Air Coolant on Surface Roughness and Tool Wear When Machining 2205 Duplex Stainless Steel

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    Cutting fluid is important to enhance machinability. However, conventional cutting fluid is uneconomical and hazardous to environment and health. Thus, non conventional coolant method is studied in order to overcome these problems. In this study, the effect of chilled air coolant on surface roughness and tool wear when machining 2205 duplex stainless steel is investigated. The compressed air is chilled by using vortex tube. Cold air and hot air is produced by means of vortex tube from the source of compressed air. This study also investigated the comparison of machining performance between conventional flood coolant and chilled air coolant. The tests were conducted on a conventional turning machine with TiAlN coated carbide tools and the constant parameters were feed rate, cutting depth, and cutting speed. Surface roughness and tool wear were measured after each run and the results were analysed. The experiment results showed that chilled air coolant gave better surface finish compared to conventional flood coolant. However, tool life was better when using conventional flood coolant compared to chilled air coolant. For both coolant method, the result showed decreasing trend for surface roughness and tool wear values when the temperature of chilled air coolant decreased

    An electrochemical DNA biosensor based gold-thiolate conjugation utilizing ruthenium complex [Ru(dppz)2(qtpy)]Cl2

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    Non toxicity and high isoelectric point of zinc oxide nanorods (ZnO NRs) are the promising materials widely used in biomolecule detection and biomedicine application. An electrochemical DNA biosensor was successfully fabricated by depositing (3-Aminopropyl)triethoxysilane and gold nanoparticles (GNPs) on the hydrothermal growth ZnO NRs. The modified surface with GNPs (35 ± 5 nm) was characterized by field emission scanning electron microscopy with energy dispersive X-ray and X-ray diffraction. The fabricated electrode was used for the label-free detection of DNA. Thiolated (–SH) single stranded DNA was immobilized onto the GNPs surface to form a gold-thiolate bond. Hybridization with complementary target DNA was performed with the presence of ruthenium complex. Immobilization and hybridization detection were performed using µAUTOLAB with cyclic voltammetric software. The measured sensitivity of the fabricated electrode for hybridization is up to 1.6 times larger than immobilization

    Diagnostic accuracy of magnetic resonance imaging targeted biopsy techniques compared to transrectal ultrasound guided biopsy of the prostate: a systematic review and meta-analysis

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    Background: Multiparametric MRI localizes cancer in the prostate, allowing for MRI guided biopsy (MRI-GB) 43 alongside transrectal ultrasound-guided systematic biopsy (TRUS-GB). Three MRI-GB approaches exist; visual estimation (COG-TB); fusion software-assisted (FUS-TB) and MRI ‘in-bore’ biopsy (IB-TB). It is unknown whether any of these are superior. We conducted a systematic review and meta-analysis to address three questions. First, whether MRI-GB is superior to TRUS-GB at detecting clinically significant PCa (csPCa). Second, whether MRI-GB is superior to TRUS-GB at avoiding detection of insignificant PCa. Third, whether any MRI-GB strategy is superior at detecting csPCa. Methods: A systematic literature review from 2015 to 2019 was performed in accordance with the START recommendations. Studies reporting PCa detection rates, employing MRI-GB and TRUS-GB were included and evaluated using the QUADAS-2 checklist. 1553 studies were found, of which 43 were included in the meta-analysis. Results: For csPCa, MRI-GB was superior in detection to TRUS-GB (0.83 vs. 0.63 [p = 0.02]). MRI-GB was superior in detection to TRUS-GB at avoiding detection of insignificant PCa. No MRI-GB technique was superior at detecting csPCa (IB-TB 0.87; COG TB 0.81; FUS-TB 0.81, [p = 0.55]). There was significant heterogeneity observed between the included studies. Conclusions: In patients with suspected PCa on MRI, MRI-GB offers superior rates of csPCa detection and reduces detection of insignificant PCa compared to TRUS-GB. No individual MRI-GB technique was found to be better in csPCa detection. Prospective adequately powered randomized controlled trials are required

    Systematic Review of Complications of Prostate Biopsy

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    AbstractContextProstate biopsy is commonly performed for cancer detection and management. The benefits and risks of prostate biopsy are germane to ongoing debates about prostate cancer screening and treatment.ObjectiveTo perform a systematic review of complications from prostate biopsy.Evidence acquisitionA literature search was performed using PubMed and Embase, supplemented with additional references. Articles were reviewed for data on the following complications: hematuria, rectal bleeding, hematospermia, infection, pain, lower urinary tract symptoms (LUTS), urinary retention, erectile dysfunction, and mortality.Evidence synthesisAfter biopsy, hematuria and hematospermia are common but typically mild and self-limiting. Severe rectal bleeding is uncommon. Despite antimicrobial prophylaxis, infectious complications are increasing over time and are the most common reason for hospitalization after biopsy. Pain may occur at several stages of prostate biopsy and can be mitigated by anesthetic agents and anxiety-reduction techniques. Up to 25% of men have transient LUTS after biopsy, and <2% have frank urinary retention, with slightly higher rates reported after transperineal template biopsy. Biopsy-related mortality is rare.ConclusionsPreparation for biopsy should include antimicrobial prophylaxis and pain management. Prostate biopsy is frequently associated with minor bleeding and urinary symptoms that usually do not require intervention. Infectious complications can be serious, requiring prompt management and continued work into preventative strategies

    Economical, environmental friendly synthesis, characterization for the production of zeolitic imidazolate framework-8 (ZIF-8) nanoparticles with enhanced CO2 adsorption

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    Zeolitic imidazole framework 8 (ZIF-8) nanoparticles were successfully synthesized in an aqueous solution at the ambient condition with a relatively low molar ratio of zinc salt and an organic ligand, Zn+2/Hmim (1: 8). ZIF-8 has remarkable thermal and chemical stability, tunable microporous structure, and a great potential for absorption, adsorption, and separation. Various physicochemical characterization techniques like X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), attenuated total reflected infrared spectroscopy (ATR-IR), thermogravimetric analysis (TGA), and surface area with pore textural properties by micromeritics gas adsorption equipment were performed to investigate the effect of base type additive triethylamine (TEA) on the morphology, crystallinity, yield, particle and crystal size, thermal stability and microporosity of ZIF-8 nanoparticles. The total quantity of basic sites and carbon dioxide (CO2) desorption aptitude was also calculated using CO2 temperature-programmed desorption (CO2-TPD) system. The pure ZIF-8 nanoparticles of 177 nm were formed at TEA/total mole ratio of 0.002. Furthermore, the size of ZIF-8 nanoparticles was decreased to 77 nm with increasing TEA/total mole ratio up to 0.004. The structures, particle sizes and textural properties of ammonia modified ZIF-8 particle can easily be tailored by the amount of aqueous ammonium hydroxide solution. The smallest ZIF-8 nanoparticles obtained were 75 nm after ammonia modification which shows excellent thermal stability and improved microporosity. The ZIF-8 basicity and uptakes of CO2 improved with TEA and ammonia modification which followed the order: A25ml–Z4 > Z4 > Z3 > Z5 > Z2 > A50ml–Z4. The proposed economical and efficient synthesis method has great potential for large-scale production of ZIF-8

    Rapid synthesis and characterization of leaf-like zeolitic imidazolate framework Sintesis cepat dan pencirian kerangka seperti daun imidazolat zeolitik

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    A two-dimensional zeolitic imidazolate framework with a leaf-like structure (ZIF-L) was synthesized in aqueous solution at room temperature with a molar ratio of Zn+2/Hmim (1: 8). Various triethylamine (TEA) concentrations were also used for the rapid production of ZIF-L. Different characterization techniques like X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) and thermogravimetric analysis (TGA) were performed to investigate the effect of base type additive triethylamine (TEA) on the crystal morphology, crystallinity, particle size and thermal stability of ZIF-L particles. From the experimental results, it was found that ZIF-L with a particle size of 5.3 μm was formed at TEA/total mole ratio of 0, but particle size was decreased when TEA/total mole ratio was increased up to 0.0003. The smallest ZIF-L particles obtained were 3 μm that showed excellent thermal stability. It can be concluded that this promising synthesis method with base-type additive would provide the new insights in the development of ZIFs materials in economical ways. © 2018, Malaysian Society of Analytical Sciences

    Optimising the Diagnosis of Prostate Cancer in the Era of Multiparametric Magnetic Resonance Imaging : A Cost-effectiveness Analysis Based on the Prostate MR Imaging Study (PROMIS)

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    Background The current recommendation of using transrectal ultrasound-guided biopsy (TRUSB) to diagnose prostate cancer misses clinically significant (CS) cancers. More sensitive biopsies (eg, template prostate mapping biopsy [TPMB]) are too resource intensive for routine use, and there is little evidence on multiparametric magnetic resonance imaging (MPMRI). Objective To identify the most effective and cost-effective way of using these tests to detect CS prostate cancer. Design, setting, and participants Cost-effectiveness modelling of health outcomes and costs of men referred to secondary care with a suspicion of prostate cancer prior to any biopsy in the UK National Health Service using information from the diagnostic Prostate MR Imaging Study (PROMIS). Intervention Combinations of MPMRI, TRUSB, and TPMB, using different definitions and diagnostic cut-offs for CS cancer. Outcome measurements and statistical analysis Strategies that detect the most CS cancers given testing costs, and incremental cost-effectiveness ratios (ICERs) in quality-adjusted life years (QALYs) given long-term costs. Results and limitations The use of MPMRI first and then up to two MRI-targeted TRUSBs detects more CS cancers per pound spent than a strategy using TRUSB first (sensitivity = 0.95 [95% confidence interval {CI} 0.92–0.98] vs 0.91 [95% CI 0.86–0.94]) and is cost effective (ICER = £7,076 [€8350/QALY gained]). The limitations stem from the evidence base in the accuracy of MRI-targeted biopsy and the long-term outcomes of men with CS prostate cancer. Conclusions An MPMRI-first strategy is effective and cost effective for the diagnosis of CS prostate cancer. These findings are sensitive to the test costs, sensitivity of MRI-targeted TRUSB, and long-term outcomes of men with cancer, which warrant more empirical research. This analysis can inform the development of clinical guidelines. Patient summary We found that, under certain assumptions, the use of multiparametric magnetic resonance imaging first and then up to two transrectal ultrasound-guided biopsy is better than the current clinical standard and is good value for money. The use of multiparametric magnetic resonance imaging before transrectal ultrasound-guided biopsy can detect more clinically significant prostate cancer and be cost effective compared with the use of imaging post-biopsy
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