17 research outputs found

    Force and impedance control for hydraulically driven hexapod robot walking on uneven terrain

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    A variety approach of multi-legged robot designs, especially on a large scale design with hydraulically driven actuators exist, but most of it still unsolved and used primitive techniques on control solutions. This made this area of research still far from demonstrating the scientific solutions, which is more towards developing and optimizing the algorithm, control technique and software engineering for practical locomotion (flexibility and reliability). Therefore in this thesis,the study is done to propose two categories of solution for statically stable and hydraulically driven hexapod robot, named COMET-IV, which are dynamic walking trajectory generation and force/impedance control implementation (during body start patching), in order to solve the stability problems (horizontal) that encountered when walking on extremely uneven terrains.Only three sensors are used for control feedback; potentiometers (each leg joint), pressure sensors (hydraulic cylinders) and attitude sensor (center of body). For dynamic walking trajectory generation, the fixed/determined of tripod walking trajectory is modified with force threshold-based, named as environment trailed trajectory (ETT),on each first step of foot during support phase (preliminary sensing uneven terrain surfaces). Moreover,the proposed dynamic trajectory generation is then upgraded with capability of omni-directional walking with a proposed center of body rotational-based method. The instability of using the ETT module alone and with proposed hybrid force/position control in the previous progress, during body patching on walking session is then solved using the proposed pull-back position-based force control (PPF). PPF controller is derived from the ETT module itself and supported by proposed compliant (switching) mechanism, logical attitude control and dynamic swing rising control. The limitation of PPF controller applied with ETT module for walking on uneven terrain contains extreme soft surface makes the study narrowed to the impedance control approaches as a replacement of PPF controller. Three new adaptive impedance controller are designed and proposed: Optimal single leg impedance control based on body inertia, Optimal center of mass—based impedance control based on body inertia and Single leg impedance control with self-tuning stiffness. To reduce the hard swinging/shaking of the robot's body in motion that arise after applying the proposed impedance controllers, fuzzy logic control via Takagaki-Sugeno-Kang (TSK) model is proposed to be cascaded on the input feedback of the controller.The study has verified the effectiveness of both categories of control unit (dynamic trajectory,force controller and impedance controllers) combination throughout several experiments of COMET-IV walking on uneven/unstructured terrains

    Insights into the pathogenesis of nicotine addiction. Could a salivary biosensor be useful in Nicotine Replacement Therapy (NRT)?

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    Nicotine has gained the attention of the medical community due to its insidious addictive mechanisms which lead to chronic consumption. The multitude of compounds derived from tobacco smoke have local and systemic negative impacts, resulting in a large number of smoking-related pathologies. The present review offers insights into nicotine addiction physiopathology, as well as social and medical implications, with emphasis on its correlation with Advanced Glycation End Products (AGEs). Therapeutic strategies and new approaches to nicotine assessment and cessation treatment are discussed, noting that such strategies could take into account the possibility of slow and gradual nicotine release from a device attached to a prosthetic piece, based on salivary nicotine-concentration feedback. This approach could offer real-time and home-based self-therapy monitoring by the physician and the patient for follow-up and improve long-term cessation treatment success- Graphical abstract

    Insights into the pathogenesis of nicotine addiction. Could a salivary biosensor be useful in Nicotine Replacement Therapy (NRT)?

    Get PDF
    Nicotine has gained the attention of the medical community due to its insidious addictive mechanisms which lead to chronic consumption. The multitude of compounds derived from tobacco smoke have local and systemic negative impacts, resulting in a large number of smoking-related pathologies. The present review offers insights into nicotine addiction physiopathology, as well as social and medical implications, with emphasis on its correlation with Advanced Glycation End Products (AGEs). Therapeutic strategies and new approaches to nicotine assessment and cessation treatment are discussed, noting that such strategies could take into account the possibility of slow and gradual nicotine release from a device attached to a prosthetic piece, based on salivary nicotine-concentration feedback. This approach could offer real-time and home-based self-therapy monitoring by the physician and the patient for follow-up and improve long-term cessation treatment success- Graphical abstract

    RABDOMIOSARCOMUL ALVEOLAR MIMÂND LEUCEMIA ACUTĂ LA O ADOLESCENTĂ CU TROMBOZĂ VENOASĂ PROFUNDĂ – CAZ CLINIC

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    Rabdomiosarcomul este cel mai frecvent tip de sarcom al ţesuturilor moi şi se caracterizează prin invadarea şi distrugerea rapidă a ţesuturilor din vecinătate, tendinţa la metastazare fiind mare. Prezintă parţial diferenţiere mioblastică, iar tipul alveolar este cel mai agresiv. Prezentăm cazul unei paciente în vârstă de 13 ani, care a acuzat tumefiere, durere şi impotenţă funcţională la nivelul membrului inferior stâng. În urma investigaţiilor imagistice, s-a decelat tromboză venoasă profundă la nivelul venei femurale stângi şi al venei iliace comune. Tromboza a avut la bază sumarea modificărilor genetice de trombofilie împreună cu activitatea factorilor tisulari tumorali. Examinările imagistice au decelat mase adenopatice retroperitoneale ce înglobau vasele mari, mase tumorale localizate la nivelul regiunii fesiere stângi şi perianale, masă tumorală la nivelul pancreasului şi multiple leziuni nodulare osoase. Neoplazia nonhematopoietică a mimat leucemia acută, lucru evidenţiat în urma efectuării medulogramei, care a decelat infliltrare medulară cu 80% blaşti atipici. Pacienta a fost diagnosticată prin examen anatomopatolgic, în urma biopsierii unei adenopatii inghinale stângi, cu rabdomiosarcom alveolar de regiune gluteală în stadiul IV, cu inflitrare medulară şi metastaze osoase, ganglionare (inghinale, pelvine, lomboaortice, perihepatice), pancreatice şi osoase

    ALVEOLAR RHABDOMYOSARCOMA MIMICKING ACUTE LEUKEMIA IN AN ADOLESCENT WITH DEEP VENOUS THROMBOSIS – CASE PRESENTATION

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    Rhabdomyosarcoma is the most common type of soft-tissue sarcoma, who invade and destroy nearby tissues. Rhabdomyosarcoma has defective myogenic differentiation and the alveolar subtype is the most aggressive, with hithgrade malignancy. We present the case of a 13-years-old girl, with a history of pain, functional impairment, red skin colour and swollen of the left thigh. The investigations have shown thrombosis on the left femoral and iliac vein, thrombosis that resulted from genetic predisposition together with the mechanisme of paraneoplastic thrombosis. The imagistic investigation documented retroperitoneal adenopathic masses encompassing the large vesels, gluteal and perianal mases, solid mass in the pancreatic head and multiple bone nodular lesions. The nonhematopoietic malignancies has masquerading acute leukemia on the bone marrow aspirate with atypical blasts (80% from cells population). The histological examination of the biopsy sample following excision of the left inguinal lymphadenopaty have revealed the final diagnosis: Stage IV alveolar rhabdomyosarcoma, with bone marrow infiltration and multiple metastases (inguinal, pelvic, periaortic, perihepatic), pancreatic and orbital metastases

    Does Diabetes Influence Oral Health in Children?

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    Background and aims: Diabetes has a high prevalence in both pediatric as well as adult populations in present times. Dental caries represents also a very serious problem form the health point of view in all population. Our study wishes to emphasize the relation between diabetes and oral health status in pediatric patients, also inquiring upon their awareness of the link between the two

    A Validated HPLC Multichannel DAD Method for the Simultaneous Determination of Amoxicillin and Doxycycline in Pharmaceutical Formulations and Wastewater Samples

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    The quality of marketed pharmaceutical formulations must be guaranteed to attain better remedial effects and lower toxicity. The wide exploitation of antibiotics may lead to their presence as residues in body fluids and wastewaters, potentially toxic to human health. Consequently, determining antibiotics in pharmaceutical formulations and water samples is of significant importance. This paper aims to explore the possibilities of a high-performance liquid chromatography coupled with diode array detection (HPLC-DAD) method to obtain a simple, fast, and efficient analytical tool for the simultaneous determination of antibiotics in pharmaceutical formulations and environmental samples. The method was completely validated with regard to specificity, linearity, detection and quantification limits, precision, accuracy, and robustness according to the requirements of existing guidelines, and was proven to be reliable and suitable for the envisioned application. The linearity study was conducted for the calibration curves in the range of 10–100 μg/mL. The limits of detection and quantification were found to be 0.2 and 0.7 μg/mL for amoxicillin and 0.3 and 1.0 μg/mL for doxycycline, respectively. The high recovery of drugs from their commercial pharmaceutical formulations (93%) and from wastewater samples (98%) indicated good accuracy and precision. The method is robust for small or deliberate changes to the chromatographic parameters, and it was successfully applied for the quantitative determination of amoxicillin and doxycycline in wastewater and commercial tablets. The obtained results proved that the validated method is appropriate for its intended use in the routine quality control and assay of both antibiotics studied
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