114 research outputs found

    An augmented Lagrangian method for image reconstruction with multiple features

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    We present an Augmented Lagrangian Method (ALM) for solving image reconstruction problems with a cost function consisting of multiple regularization functions with a data fidelity constraint. The presented technique is used to solve inverse problems related to image reconstruction, including compressed sensing formulations. Our contributions include an improvement for reducing the number of computations required by an existing ALM method, an approach for obtaining the proximal mapping associated with p-norm based regularizers, and lastly a particular ALM for the constrained image reconstruction problem with a hybrid cost function including a weighted sum of the p-norm and the total variation of the image. We present examples from Synthetic Aperture Radar imaging and Computed Tomography

    An augmented Lagrangian method for autofocused compressed SAR imaging

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    We present an autofocus algorithm for Compressed SAR Imaging. The technique estimates and corrects for 1-D phase errors in the phase history domain, based on prior knowledge that the reflectivity field is sparse, as in the case of strong scatterers against a weakly-scattering background. The algorithm relies on the Sparsity Driven Autofocus (SDA) method and Augmented Lagrangian Methods (ALM), particularly Alternating Directions Method of Multipliers (ADMM). In particular, we propose an ADMM-based algorithm that we call Autofocusing Iteratively Re-Weighted Augmented Lagrangian Method (AIRWALM) to solve a constrained formulation of the sparsity driven autofocus problem with an ℓp-norm, p ≤ 1 cost function. We then compare the performance of the proposed algorithm's performance to Phase Gradient Autofocus (PGA) and SDA [2] in terms of autofocusing capability, phase error correction, and computation time

    A Rare Coronary Artery Anomaly Presented With Acute Myocardial Infarction in a Young Patient

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    Single coronary artery (SCA) anomaly is a rare angiographic finding and majority of the patients are asymptomatic; however, myocardial ischemia and sudden death have been reported. We report a 26 year old male patient with SCA with acute myocardial infarction, in whom successful coronary angioplasty was performed to the left anterior descending artery through an anomalous of the right coronary artery, originating from the proximal part of the circumflex coronary artery. The patient was discharged with uneventful recovery

    Znaczenie badania krwi pobranej z żył tarczowych górnych i dolnych w rozpoznawaniu raka tarczycy

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    Introduction: We aimed to determine whether levels of thyroglobulin measured in blood from the inferior-superior thyroid veins and the peripheral antecubital vein could predict the presence of thyroid carcinoma in patients undergoing surgery for thyroid diseases. Material and methods: Sixty-one patients were prospectively enrolled in the study. Levels of thyroglobulin were analysed. Sensitivity, specificity, positive predictive values (PPV) and negative predictive values (NPV) of these markers were investigated. Results: Twenty-six out of 61 patients (42.6%) with malignancy were diagnosed. The levels of thyroglobulin in the inferior-superior thyroid veins were higher than those in the peripheral antecubital vein (p = 0.001). The levels of thyroglobulin in the blood taken from the antecubital vein and the inferior-superior thyroid veins did not differ between benign and malignant thyroid disorders. For thyroglobulin, sensitivity was 33.3%, specificity 60.6%, PPV 27.8%, and NPV 66.7% respectively. Conclusion: Thyroglobulin levels in the antecubital vein compared to the inferior-superior thyroid veins were not significant either in benign or malignant disorders.Wstęp: Celem badania było ustalenie, czy oznaczenie stężeń tyreoglobuliny we krwi pobranej z żył tarczowych górnych i dolnych oraz z żyły przedłokciowej ma wartość prognostyczną w wykrywaniu nowotworów tarczycy u chorych poddawanych zabiegom chirurgicznym z powodu chorób tarczycy. Materiał i metody: Do tego prospektywnego badania włączono 61 chorych. Analizowano wartości stężeń tyreoglobuliny. Badano czułość, swoistość oraz wartość prognostyczną dodatnią (PPV) i ujemną (NPV) tych wskaźników. Wyniki: U 26 spośród 61 chorych (42,6%) rozpoznano chorobę nowotworową. Stężenia tyreoglobuliny w żyłach tarczowych dolnych i górnych były wyższe niż stężenia mierzone we krwi pobranej z żyły przedłokciowej (p = 0,001). Stężenia tyreoglobuliny w próbkach krwi pobranych z żyły przedłokciowej i żył tarczowych nie różniły się istotnie między osobami z łagodnymi i złośliwymi guzami tarczycy. Oznaczenie tyreoglobuliny cechowało się czułością wynoszącą 33,3%, swoistością równą 60,6%, PPV — 27,8% i NPV — 66,7%. Wnioski: Porównanie stężeń tyreoglobuliny w żyle przedłokciowej i w żyłach tarczowych górnych i dolnych nie miało istotnego znaczenia diagnostycznego w wykrywaniu zarówno zmian łagodnych, jak i złośliwych

    The effects of prenatal and neonatal exposure to electromagnetic fields on infant rat myocardium

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    Introduction: Electromagnetic fields (EMF) have adverse effects as a result of widespread use of electromagnetic energy on biological systems. The aim of this study was to investigate the effects of prenatal exposure to EMF on rat myocardium by biochemical and histopathological evaluations

    Evaluation of sexual functional status and consistency of scales in patients with hypogonadotropic hypogonadism before and after testosterone replacement therapy: a single-center experience

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    ABSTRACT Objective: This study aimed to investigate the frequency of sexual dysfunction and the effect of short-term testosterone replacement therapy on sexual functions in congenital hypogonadism patients. Furthermore, we sought to reveal the consistency of the self-report scales used for the diagnosis of sexual dysfunction and the relationship between biochemical parameters. Materials and methods: The study was conducted on 47 young male patients aged above 18 years who were diagnosed with hypogonadotropic hypogonadism. Short (IIEF-5) and long (IIEF-15) forms of the International Index of Erectile Function and Arizona Sexual Experiences Scale (ASEX) were applied before treatment under the supervision of a physician. The patients’ blood pressure, height, and weight were measured, and their luteinizing hormone (LH), FSH, and total testosterone levels were recorded. Patients who started their treatments were called for a follow-up checkup after 6 months. Their blood pressure, height, and weight were measured by reapplying the ASEX, IIEF-5, and IIEF-15. In addition, their LH, FSH, and total testosterone levels in the biochemical tests were rerecorded. Results: In this study, the sexual dysfunction status of patients diagnosed with hypogonadotropic hypogonadism before and after treatment was evaluated using the ASEX, IIEF-15, and IIEF-5 scales. A decrease in sexual dysfunction was observed in all three scales after treatment compared with that before treatment. The IIEF-5 and IIEF-15 scales were found to be uncorrelated in terms of the pretreatment values but were correlated in terms of the post-treatment values. Although a correlation was observed between ASEX and IIEF-5 before treatment, no correlation was detected between ASEX and IIEF-15. After the treatment, ASEX was found to be correlated with both IIEF-5 and IIEF-15. The results of the scales indicated the correlation in all categories, except the pretreatment results of the IIEF-15 scale. Conclusion: The results of the current study demonstrated a significant improvement in the sexual function of hypogonadism patients undergoing short-term testosterone therapy. The ASEX, IIEF-5, and IIEF-15 scales used in the diagnosis and follow-up of sexual dysfunction were useful for evaluating sexual functions in hypogonadotropic hypogonadism patients

    VSC-Based D-STATCOM With Selective Harmonic Elimination

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    This paper describes the design, implementation, and performance of a medium-size distribution-type static synchronous compensator (D-STATCOM) with the simplest two-level three-leg voltage-source converter (VSC) topology. Reactive-power control is achieved by phase-shift-angle control, and VSC harmonies are eliminated by selective harmonic elimination method (SHEM). VSC has been designed at the highest low-voltage level of 1 kV and connected to a medium-voltage (W) bus through a, low-pass input filter and Delta/Y-connected MV/1-kV coupling transformer. At the MV side of D-STATCOM, line-current harmonics are minimized to comply with the IEEE Std. 519-1992 for the weakest supply conditions by applying 8-angle TLN2 elimination technique. This necessitates switching the water-cooled high-voltage insulated-gate bipolar transistor (HV-IGBT) modules at 850 Hz, thus eliminating 5th, 7th, 11th, 13th, 17th, 19th, 23rd, and 25th voltage harmonics at the input of VSC. By carefully designing the laminated bus system and selecting minimum stray-inductance dc-link capacitors directly mountable on the laminated bus, stray inductance of the commutation path is brought to a nearly absolute minimum of 60 nH, thus maximizing the utilization of wire-bond single-side cooled RV IGBTs and eliminating the need for RCD clamping snubbers. The performance of SHEM, together with the phase-shift-angle control, has been tested in the field on a 0-1780-kVAr capacitive 6.3-kV VSC-based D-STATCOM (-750/+ 900 kVAr VSC) prototype. Field-test results show that SHEM, together with phase-shift-angle control, leads to optimum switching frequency and device utilization for RV IGBTs and high system performance at the expense of slower response as compared to the other known control techniques

    Prolonged pleural catheters in the management of pleural effusions due to breast cancer

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    WOS: 000332779900012PubMed ID: 24605219Background: Breast cancer is the second most common etiologic cause in malignant pleural effusions (MPE). The aim of this study was to investigate the efficacy of long term pleural catheters in inducing self sclerosis in pleural effusions of breast cancer patients. Methods: In this study, 26 patients with breast cancer relapleural effusions that occurred between January 2011 and July 2013, who were considered not to undergo any other treatments and managed with prolonged pleural catheters (Jackson-Pratt silicone flat drain), were retrospectively analyzed. Thirty pleural catheters were inserted in 26 patients. All patients were female, mean age was 52 (range, 37-66) years old. Drainage over 1,500 mL per day was not allowed in order to avoid a lung edema. The catheters were removed in patients who had restoration of lung expansion and drainage under 50 mL/day. Results: The histologic subtypes in pleural effusions were invasive ductal carcinoma in 18 patients, ductal carcinoma in situ in 4, invasive lobular carcinoma in 2, tubular carcinoma in 1, and medullary carcinoma in 1. Three of the 26 patients underwent bilateral catheter insertion, and one patient underwent a reinsertion of the catheter into the same hemithorax due to a recurrence. The catheters were retained for a mean period of 18 days (range, 11-38 days). In one patient with invasive ductal carcinoma and paramalignant pleural effusion (PMPE) (3.8%), a recurrent pleural effusion was seen 34 days after removal of the catheter. There were no complications. One patient died while the catheter was in place. Conclusions: Prolonged catheters for the management of pleural effusions in selected patients have become more popular than other treatment alternatives due to a shorter length of stay and lower costs. We recommend the use of Jackson Pratt (JP) silicone flat drains which in our opinion provide effective pleurodesis in addition to easy application in recurrent effusions caused by breast cancer
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