339 research outputs found

    Performance of Unsupervised Change Detection Method Based on PSO and K-means Clustering for SAR Images

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    This paper presents unsupervised change detection method to produce more accurate change map from imbalanced SAR images for the same land cover. This method is based on PSO algorithm for image segmentation to layers which classify by Gabor Wavelet filter and then K-means clustering to generate new change map. Tests are confirming the effectiveness and efficiency by comparison obtained results with the results of the other methods. Integration of PSO with Gabor filter and k-means will providing more and more accuracy to detect a least changing in objects and terrain of SAR image, as well as reduce the processing time

    Effect of Deposition Time on the Optical Characteristics of Chemically Deposited Nanostructure PbS Thin Films

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    AbstractPbS thin films are good materials for antireflection coatings and for solar thermal applications in flat-plat collectors, house heating for solar chick brooding, etc. Nanocrystalline PbS thin films were deposited on glass substrates with various deposition times using chemical bath deposition technique. The study was carried out for thicknesses in the range (500-660nm). The crystalline size of these films was studied by atomic force microscope AFM. A dense surface composed of multilayered grains of films was obtained with the crystal size around 37.67nm. The optical properties of these films have been studied and show that PbS thin films have allowed direct transition and the values of energy gap varied between (1.88-1.55eV) with increasing film thickness, The large optical band gap in the films is attributed to the quantum coefficient effect. Influences of thermal treatments under various annealing temperatures on the optical properties for some deposition films were studied

    Least Squares Method For Solving Integral Equations With Multiple Time Lags

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    The main purpose of this work is to propose an approximate method to solveintegral equation with multiple time lags (IEMTL) namely least squares methodwith aid of Chebyshev polynomials of (first, second, third, and fourth)kinds.Example is given as an application of least squares method with aid of four kindsof Chebyshev polynomials

    Left atrial pump strain predicts long-term survival after transcatheter aortic valve implantation

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    BACKGROUND This study aims at investigating left atrial (LA) deformation by left atrial reservoir (LARS) and pump strain (LAPS) and its implications for long-term survival in patients with severe aortic stenosis (AS) undergoing transcatheter aortic valve implantation (TAVI). METHODS Speckle tracking echocardiography was performed in 198 patients with severe AS undergoing TAVI. Association of strain parameters with cardiovascular mortality was determined. RESULTS Over a follow-up time of 5 years, 49 patients (24.7%) died. LAPS was more impaired in non-survivors than survivors (P = 0.010), whereas no difference was found for LARS (P = 0.114), LA ejection fraction (P = 0.241), and LA volume index (P = 0.292). Kaplan-Meier analyses yielded a reduced survival probability according to the optimal threshold for LAPS (P = 0.002). A more impaired LAPS was associated with increased mortality risk (HR 1.12 [95% CI 1.02-1.22]; P = 0.014) independent of LVEF, LAVI, age, and sex. Addition of LAPS improved multivariable echocardiographic (LVEF, LAVI) and clinical (age, sex) models with potential incremental value for mortality prediction (P = 0.013 and P = 0.031, respectively). In contrast, LARS and LAVI were not associated with mortality. CONCLUSIONS In patients undergoing aortic valve replacement for severe AS, LAPS was impaired in patients dying during long-term follow-up after TAVI, differentiated survivors from non-survivors, was independently associated with long-term mortality, and yielded potential incremental value for survival prediction after TAVI. LAPS seems useful for risk stratification in severe AS and timely valve replacement

    Deriving measures of intensive care unit antimicrobial use from computerized pharmacy data: Methods, validation, and overcoming barriers

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    OBJECTIVE: To outline methods for deriving and validating intensive care unit (ICU) antimicrobial utilization (AU) measures from computerized data and to describe programming problems that emerged. DESIGN: Retrospective evaluation of computerized pharmacy and administrative data. SETTING: ICUs from four academic medical centers over 36 months. INTERVENTIONS: Investigators separately developed and validated programming code to report AU measures in selected ICUs. Antibacterial and antifungal drugs for systemic administration were categorized and expressed as antimicrobial days (each day that each antimicrobial drug was given to each patient) and patient-days on antimicrobials (each day that any antimicrobial drug was given to each patient). Monthly rates were compiled and analyzed centrally with ICU patient-days as the denominator. Results were validated against data collected from manual medical record review. Frequent discussion among investigators aided identification and correction of programming problems. RESULTS: AU data were successfully programmed though a reiterative process of computer code revision. After identifying and resolving major programming errors, comparison of computerized patient-level data with data collected by manual medical record review revealed discrepancies in antimicrobial days and patient-days on antimicrobials ranging from <1% to 17.7%. The hospital for which numerator data were derived from electronic medication administration records had the least discrepant results. CONCLUSIONS: Computerized AU measures can be derived feasibly, but threats to validity must be sought and corrected. The magnitude of discrepancies between computerized AU data and a gold standard based on manual chart review varies, with electronic medication administration records providing maximal accuracy

    Isolated hepatic actinomycosis: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>Actinomyces are slow growing, non-spore forming, gram-positive, branching bacilli that thrive in anaerobic and microareophilic conditions. Actinomyces are more commonly associated with oral and cervicofacial infections. Hepatic involvement in infections of the abdomen (known as isolated hepatic actinomycosis) is rare, accounting for only 5% of all cases of actinomycosis.</p> <p>Case presentation</p> <p>We present the case of a 75-year-old Caucasian woman with a 3-month history of night sweats, fever, chills, abdominal bloating, anorexia, weight-loss, and early satiety. The patient was found to have isolated hepatic actinomycosis infection after undergoing a laparotomy with a biopsy of the liver. The patient has now recovered.</p> <p>Conclusion</p> <p>Isolated hepatic actinomycosis is a rare and often overlooked etiology for a liver mass. Given its subacute presentation and nondescript symptomatology, physicians should be aware of this differential and the potential pitfalls in diagnosis and management.</p

    The effectiveness of neuromuscular warm-up strategies, that require no additional equipment, for preventing lower limb injuries during sports participation: a systematic review

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    PMCID: PMC3408383The electronic version of this article is the complete one and can be found online at: http://www.biomedcentral.com/1741-7015/10/75. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited

    Heart rate variability and target organ damage in hypertensive patients

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    Background: We evaluated the association between linear standard Heart Rate Variability (HRV) measures and vascular, renal and cardiac target organ damage (TOD). Methods: A retrospective analysis was performed including 200 patients registered in the Regione Campania network (aged 62.4 ± 12, male 64%). HRV analysis was performed by 24-h holter ECG. Renal damage was assessed by estimated glomerular filtration rate (eGFR), vascular damage by carotid intima-media thickness (IMT), and cardiac damage by left ventricular mass index. Results: Significantly lower values of the ratio of low to high frequency power (LF/HF) were found in the patients with moderate or severe eGFR (p-value < 0.001). Similarly, depressed values of indexes of the overall autonomic modulation on heart were found in patients with plaque compared to those with a normal IMT (p-value <0.05). These associations remained significant after adjustment for other factors known to contribute to the development of target organ damage, such as age. Moreover, depressed LF/HF was found also in patients with left ventricular hypertrophy but this association was not significant after adjustment for other factors. Conclusions: Depressed HRV appeared to be associated with vascular and renal TOD, suggesting the involvement of autonomic imbalance in the TOD. However, as the mechanisms by which abnormal autonomic balance may lead to TOD, and, particularly, to renal organ damage are not clearly known, further prospective studies with longitudinal design are needed to determine the association between HRV and the development of TOD

    Overview On Surgical Management Of Overactive Bladder

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    Overactive bladder syndrome is a persistent and incapacitating disorder that has profound medical, psychological, and social implications, greatly impacting the wellbeing of countless individuals globally. A significant number of individuals experience urine urgency, which can be extremely bothersome. The primary indicator of overactive bladder (OAB) is a sense of urgency, often accompanied by increased urine frequency and nocturia. After ruling out other medical conditions with similar symptoms, the initial approach to managing OAB is providing guidance on fluid consumption and bladder training. If needed, antimuscarinic medicines may be added as a supplement. If patients have significant distress from OAB symptoms even after maximizing medicinal treatment, they may choose to undergo invasive procedures. There is currently a limited understanding of the hierarchical structure of central nervous system control. However, the use of functional imaging is starting to reveal the difficulties that need to be addressed in this area. Current research is exploring the use of botulinum neurotoxin-A injection, oral β3-adrenergic agonists, and innovative methods for nerve stimulation as potential therapies. The inherent subjectivity of urine urgency, the absence of animal models, and the complex pathophysiology of overactive bladder (OAB) pose substantial obstacles to achieving effective clinical therapy
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