100 research outputs found

    Model following control with discrete time SMC for time-delayed bilateral control systems

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    This paper proposes a new algorithm based on model following control to recover the uncompensated slave disturbance on time delayed motion control systems having contact with environment. In the previous works, a modified Communication Disturbance Observer (CDOB) was shown to be successful in ensuring position tracking in free motion under varying time delay. However, experiments show that due to the imperfections in slave plant Disturbance Observer (DOB) when there is rapid change of external force on the slave side, as in the case of environment contact, position tracking is degraded. This paper first analyzes the effect of environment contact for motion control systems with disturbance observers. Following this analysis, a model following controller scheme is proposed to restore the ideal motion on the slave system. A virtual plant is introduced which accepts the current from the master side and determines what the position output would be if there was no environment. Based on the error bet ween actual system and model system, a discrete time sliding mode controller is designed which enforces the real slave system to track the virtual slave output. In other words, convergence of slave position to the master position is achieved even though there is contact with environment. Experimental verification of the proposed control scheme also shows the improvement in slave position tracking under contact forces

    LiDAR Buoy Detection for Autonomous Marine Vessel Using Pointnet Classification

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    Maritime autonomy, specifically the use of autonomous and semi-autonomous maritime vessels, is a key enabling technology supporting a set of diverse and critical research areas, including coastal and environmental resilience, assessment of waterway health, ecosystem/asset monitoring and maritime port security. Critical to the safe, efficient and reliable operation of an autonomous maritime vessel is its ability to perceive on-the-fly the external environment through onboard sensors. In this paper, buoy detection for LiDAR images is explored by using several tools and techniques: machine learning methods, Unity Game Engine (herein referred to as Unity) simulation, and traditional image processing. The Unity Game Engine (herein referred to as Unity) simulation data was used for the training and testing of a Pointnet neural network model while the labeled real-world maritime environment point cloud data was used for the model validation. Fitting the Pointnet model on the simulation data, after some data alignment with the LiDAR images allowed for accurate classification of buoys on the real-world data with the 93% of accuracy. A traditional image processing approach using 2D occupancy maps to detect the buoys by shape was used as well and is outlined in the paper

    Potential benefits of hyperbaric oxygen therapy on atherosclerosis and glycaemic control in patients with diabetic foot

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    Wstęp: Celem badania była ocena wpływu leczenia tlenem w komorze hiperbarycznej (HBOT, hyperbaric oxygen therapy) na kontrolę glikemii, czynniki ryzyka miażdżycy, wskaźniki zapalenia oraz inne kliniczne i laboratoryjne parametry u chorych z owrzodzeniem w przebiegu zespołu stopy cukrzycowej poddanych systemowej HBOT. Materiał i metody: Do badania włączono 28 chorych z owrzodzeniem stopy 2-4 stopnia według skali Wagnera. Wszyscy chorzy odbyli 30 sesji terapii 100-procentowym tlenem przy ciśnieniu 2,4 ATA przez około 105 minut, 5 razy w tygodniu. Zmierzono następujące parametry: glikemię na czczo, odsetek HbA1c, wskaźnik insulinooporności HOMA-IR, stężenie wysokoczułego białka C-reaktywnego (hs-CRP, high sensitivity C-reactive protein), stężenie kwasu moczowego, średnią objętość płytek krwi, a ponadto zbadano morfologię krwi i profil lipidowy. Wyniki: Po zakończeniu terapii stwierdzono istotną poprawę średnich wartości wszystkich badanych parametrów. Wnioski: Wykazano, że HBOT wpływa korzystnie na czynniki ryzyka miażdżycy i kontrolę glikemii u chorych na cukrzycę. Potrzebne są dalsze, prowadzone na szeroką skalę badania z randomizacją, aby ocenić ogólnoustrojowe efekty HBOT. (Endokrynol Pol 2010; 61 (3): 275-279)Introduction: The aim of this study was to investigate the effects of hyperbaric oxygen therapy (HBOT) on glycaemic control, atherosclerosis, inflammatory markers, and other clinical and laboratory parameters in patients undergoing systemic HBOT for diabetic foot ulcerations. Material and methods: Twenty-eight patients with Wagner grade 2-4 diabetic foot ulcerations were included. All patients were given 100% oxygen at 2.4 absolute atmosphere (ATA) for about 105 minutes, five times a week for a total of 30 sessions. Fasting blood glucose (FBG), haemoglobin A1c (HbA1c), homeostasis model measurement-insulin resistance (HOMA-IR), high sensitivity C-reactive protein (hs-CRP), uric acid, mean platelet volume (MPV), complete blood count, and lipid profile were tested. Results: Upon completion of treatment, a statistically significant improvement was observed in the mean values of all assessed parameters. Conclusions: HBOT was shown to have beneficial effects on atherosclerosis and glycaemic control in diabetic patients. Further large-scale randomized studies are needed to study the systemic effects of HBOT. (Pol J Endocrinol 2010; 61 (3): 275-279

    Can proliferative hypertrophic scars of the median sternotomy incision predict the occurrence and characteristics of urethral stricture?

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    Conclusion: A poorly healed median stemotomy incision scar can predict a poor wound healing in the urethra tissue. Further large scale, multi-center and prospective studies are needed to clarify this relationship

    Obstrüktif uyku apneli ve horlayan erişkin erkek hastaların dentofasiyal özelliklerinin değerlendirilmesi

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    Amaç: Bu çalışmanın amacı obstrüktif uyku apne sendromu (OUAS) olan erişkin erkek hastaların kraniofasiyal morfolojik özellikleri değerlendirmektir. Gereç ve Yöntem: Çalışmada 80 erkek hastanın (60 sefalogramları değerlendirildi. Bireyler Grup 1: horlama (AHİ5); Grup 2: hafif OUAS (5AHİ15); Grup 3: orta OUAS(15 AHİ30) ; Grup 4: şiddetli OUAS (AHİ30) olarak değerlendirildi. Sefalogramlar üzerinde hyoid, dil kökü ve yumuşak damak konumu, kranioservikal postür ve havayolu genişliğini belirleyen ölçümler yapıldı. Gruplar arasındaki farklar normal dağılım gösteren değişkenlerde tek yönlü varyans analizi ve Duncan testiyle, normal dağılım göstermeyen değişkenlerde Kruskal düzeltmesi uygulanarak Mann Whitney U testiyle yapıld

    Štetni učinci pušenja tijekom trudnoće na DNA i razine reaktivnih oblika kisika (ROS) u krvi majke i novorođenčeta

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    Some of the genotoxic/carcinogenic substances or metabolites in cigarette smoke are capable of passing through the placenta and harming a newborn’s health. Smoking is also known as a factor in the formation of oxidative damage and the main mechanism involved in the carcinogenic process. Predetermining this genotoxic risk can be successfully achieved by measuring certain parameters of oxidative stress. The comet assay is considered an important biomarker for the evaluation of genotoxic substances and is effective for detecting DNA damage caused by smoking. This study examined third trimester bloods and the cord blood of 28 actively smoking and 22 non-smoking mothers in terms of DNA damage and oxidative stress parameters. Cu/Zn superoxide dismutase (CuZn-SOD), malondialdehyde (MDA), catalase (CAT), plasma nitrite/nitrates (NO2•/NO3•), selenium-dependent glutathione peroxidase (Se-GPx), Cu, and Zn levels were measured as indicators of oxidative damage. There were no significant increases in DNA damage of the actively smoking pregnant group in comparison with the non-smoking pregnant group, either in the third trimester or cord blood. Oxidative stress parameters of smoker and non-smoker groups were statistically different for MDA (p<0.05), CuZn-SOD (p<0.01), Se-GPx (p<0.05) values while the difference was not significant for NO2•/NO3•, CAT, Zn, and Cu values. The same values were also investigated in cord blood, and only NO2•/NO3• (p<0.01), Se-GPx (p<0.01 and CAT (p<0.001) values were found statistically different. Smoking mothers may have been exposed to more oxidative stress than non-smoking mothers.Pojedine genotoksične/kancerogene supstancije ili metaboliti u cigaretnom dimu mogu proći kroz posteljicu i naštetiti zdravlju novorođenčeta. Pušenje je također poznato kao čimbenik pri nastanku oksidacijskog oštećenja DNA i u procesu kancerogeneze. Ovaj genotoksični rizik može se uspješno odrediti mjerenjem određenih parametara oksidacijskog stresa. Komet-test smatra se važnim biološkim biljegom pri evaluaciji genotoksičnih supstancija i iznimno učinkovitim sredstvom pronalaženja oštećenja DNA uzrokovanih pušenjem. Ova studija proučava krv trudnica u trećem tromjesečju trudnoće i fetalnu krv 28 majki aktivnih pušačica te 22-ju majki nepušačica vezano za oksidacijska oštećenja DNA i parametre oksidacijskog stresa. Razine Cu/Zn superoksidne dismutaze (CuZn-SOD), malondialdehida (MDA), katalaze (CAT), nitrita/nitrata u plazmi (NO2-/NO3-), selenijeve glutation peroksidaze (Se-GPx), Cu i Zn mjerene su kao pokazatelji oksidacijskog oštećenja. Nije bilo značajnih povećanja oštećenja DNA u skupini trudnica aktivnih pušačica u usporedbi sa skupinom trudnica nepušačica, ni u krvi iz trećeg tromjesečja ni u fetalnoj krvi. Parametri oksidacijskog stresa pušačke i nepušačke skupine bili su statistički različiti za vrijednosti MDA (p<0,05), CuZn-SOD (p<0,01), Se-GPx (P<0,05), dok razlika nije bila značajna za vrijednosti NO2-/NO3-, CAT, Zn i Cu. Iste su vrijednosti ispitane i u fetalnoj krvi, a jedino su vrijednosti NO2-/NO3- (p<0,01), Se-GPx (p<0,01) i CAT (p<0,001) bile statistički različite. Vjerojatno je da su majke pušačice bile izložene većem oksidacijskom stresu od majki nepušačica

    Atrial natriuretic peptide and posterior pituitary neurohormone changes in patients with acute schizophrenia

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    Conclusion: The obtained data indicate that the AVP level was higher, but OXT and ANP levels were lower in the patients having acute schizophrenia. Specifically OXT is related with reduced disease severity and increased functionality

    Antinuclear antibody testing in a Turkish pediatrics clinic: is it always necessary?

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    Introduction:&nbsp;the term anti-nuclear antibody (ANA) is used to define a large group of autoantibodies which specifically bind to nuclear elements. Although healthy individuals may also have ANA positivity, the measurement of ANA is generally used in the diagnosis of autoimmune disorders. However, various studies have shown that ANA testing may be overused, especially in pediatrics clinics. Our aim was to investigate the reasons for antinuclear antibody (ANA) testing in the general pediatrics and pediatric rheumatology clinics of our hospital and to determine whether ANA testing was ordered appropriately by evaluating chief complaints and the ultimate diagnoses of these cases. Methods:&nbsp;the medical records of pediatric patients in whom ANA testing was performed between January 2014 and June 2016 were retrospectively evaluated. Subjects were grouped according to the indication for ANA testing and ANA titers. Results:&nbsp;ANA tests were ordered in a total of 409 patients during the study period, with 113 positive ANA results. The ANA test was ordered mostly due to joint pain (50% of the study population). There was an increased likelihood of autoimmune rheumatic diseases (ARDs) with higher ANA titer. The positive predictive value of an ANA test was 16% for any connective tissue disease and 13% for lupus in the pediatric setting. Conclusion:&nbsp;in the current study, more than one-fourth of the subjects were found to have ANA positivity, while only 15% were ultimately diagnosed with ARDs. Our findings underline the importance of an increased awareness of correct indications for ANA testing

    Volume CXIV, Number 4, November 7, 1996

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    Objective: Turner syndrome (TS) is a chromosomal disorder caused by complete or partial X chromosome monosomy that manifests various clinical features depending on the karyotype and on the genetic background of affected girls. This study aimed to systematically investigate the key clinical features of TS in relationship to karyotype in a large pediatric Turkish patient population.Methods: Our retrospective study included 842 karyotype-proven TS patients aged 0-18 years who were evaluated in 35 different centers in Turkey in the years 2013-2014.Results: The most common karyotype was 45,X (50.7%), followed by 45,X/46,XX (10.8%), 46,X,i(Xq) (10.1%) and 45,X/46,X,i(Xq) (9.5%). Mean age at diagnosis was 10.2±4.4 years. The most common presenting complaints were short stature and delayed puberty. Among patients diagnosed before age one year, the ratio of karyotype 45,X was significantly higher than that of other karyotype groups. Cardiac defects (bicuspid aortic valve, coarctation of the aorta and aortic stenosis) were the most common congenital anomalies, occurring in 25% of the TS cases. This was followed by urinary system anomalies (horseshoe kidney, double collector duct system and renal rotation) detected in 16.3%. Hashimoto's thyroiditis was found in 11.1% of patients, gastrointestinal abnormalities in 8.9%, ear nose and throat problems in 22.6%, dermatologic problems in 21.8% and osteoporosis in 15.3%. Learning difficulties and/or psychosocial problems were encountered in 39.1%. Insulin resistance and impaired fasting glucose were detected in 3.4% and 2.2%, respectively. Dyslipidemia prevalence was 11.4%.Conclusion: This comprehensive study systematically evaluated the largest group of karyotype-proven TS girls to date. The karyotype distribution, congenital anomaly and comorbidity profile closely parallel that from other countries and support the need for close medical surveillance of these complex patients throughout their lifespa
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