185 research outputs found
Modeling and fabrication of electrostatically actuated diaphragms for on-chip valving of MEMS-compatible microfluidic systems
This paper presents an analytical model to estimate the actuation potential of an electrostatic parylene-C diaphragm, processed on a glass wafer using standard microelectromechanical systems (MEMS) process technology, and integrable to polydimethylsiloxane (PDMS) based lab-on-a-chip systems to construct a normally-closed microvalve for flow manipulation. The accurate estimation of the pull-in voltage of the diaphragm is critical to preserve the feasibility of integration. Thus, we introduced an analytical model, in a good agreement with the finite element method (FEM), to extend the solution of the pull-in instability by including the effect of nonlinear stretching for multilayered circular diaphragms. We characterized the operation of fabricated diaphragms with a 300 mu m radius for the parameters, including pull-in voltage (221 V on average), opening and closing response times (in microseconds), repeatability (more than 50 times), and touch area (25.3% +/- 2.6% at pull-in potential). The experimental pull-in voltage shows close accuracy with the predicted results. Moreover, the diaphragm, sealed with a PDMS microchannel, was tested under fluid flow to prove the applicability of microfluidic integration. The hybrid fabrication method enables the realization of optically transparent and durable electrostatic microvalves for complex functioning of polymer-based microfluidic systems, as the extended analytical formulation permits accurate modeling of operation.This paper presents an analytical model to estimate the actuation potential of an electrostatic parylene-C diaphragm, processed on a glass wafer using standard microelectromechanical systems (MEMS) process technology, and integrable to polydimethylsiloxane (PDMS) based lab-on-a-chip systems to construct a normally-closed microvalve for flow manipulation. The accurate estimation of the pull-in voltage of the diaphragm is critical to preserve the feasibility of integration. Thus, we introduced an analytical model, in a good agreement with the finite element method (FEM), to extend the solution of the pull-in instability by including the effect of nonlinear stretching for multilayered circular diaphragms. We characterized the operation of fabricated diaphragms with a 300 µm radius for the parameters, including pull-in voltage (221 V on average), opening and closing response times (in microseconds), repeatability (more than 50 times), and touch area (25.3% ± 2.6% at pull-in potential). The experimental pull-in voltage shows close accuracy with the predicted results. Moreover, the diaphragm, sealed with a PDMS microchannel, was tested under fluid flow to prove the applicability of microfluidic integration. The hybrid fabrication method enables the realization of optically transparent and durable electrostatic microvalves for complex functioning of polymer-based microfluidic systems, as the extended analytical formulation permits accurate modeling of operation
Is Routine Diagnostic Radioiodine Whole-Body Scintigraphy Needed in Patients who Received Ablative doses of Radioiodine for Differentiated Thyroid Carcinoma?
Aim: The present large-series retrospective sought to assess DWBS findings 6‒12 weeks after RIAT in DTC patients in various risk groups. In addition, the study compared patients’ simultaneous sTg levels.Material and Methods: The follow-up data of 2879 patients who had received RIAT for DTC between 1998 and 2016 were evaluated for inclusion in the study. The study retrospectively evaluated the following: age at the time of diagnosis; gender; histopathological features of thyroidectomy materials (histological subtype, variant, dimension, multi-focality, thyroid capsule, and vascular invasion of tumors); TNM stage; ATA classification; sTg, suppressed-serum Tg, and antiTg antibody levels; and DWBS findings. Patients were categorized according to sTg level (undetectable, 1‒10 ng/ml, and >10 ng/ml). Then, the DWBS findings were analyzed according to sTg level.Results: The study analyzed 2184 patients (1805 F, 379 M; mean age: 43.54±12.64). In 2077 (95%) patients, the DWBSs performed 6‒12 months after RIAT had shown no pathological uptake throughout the entire body. Pathological uptake had been detected in the neck and outside the neck in 88 (4%) and 19 (1%) patients, respectively. All patients who had had normal DWBSs also had had undetectable simultaneous sTg levels. In addition, the DWBSs had been normal in 187 (8%) patients who had had simultaneous sTg levels> 1 ng/ml and in 286 (13%) patients who had had levels > 10 ng/ml. In all patients who had pathological uptake in DWBSs, simultaneous sTg levels were > 1ng/ml, and in 47, they were> 10 ng/ml.Conclusion: Routine DWBS seems to be unnecessary, even in high-risk DTCs. However, in patients who have detectable levels of serum sTg, it could be performed to localize the disease and plan patient management
Ga-68 DOTATATE Accumulation in Sarcoidosis
We aimed in this case series to show Ga-68 DOTATATE uptake in relation with disease activity in sarcoidosis cases. 8 patients with previous diagnosis of sarcoidosis were included to the study. Ga-68 DOTATATE PET/CT was performed to evaluate of disease activity. Disease activity was described clinically by chest disease specialist by evaluation of lung function tests, serum ACE measurements and thorax CT. Correlation between Ga-68 DOTATATE uptake and disease activity was analyzed. Ga-68 DOTATATE PET/CT as a combination of SSR scintigraphy and anatomical imaging might be beneficial in the evaluation of active sarcoidosis
The Role of 18F-Flourodeoxyglucose (18F-FDG) Positron Emission Tomography/Computed Tomography (PET/CT) in Pelvic and Paraaortic Lymph Node Staging of Uterine Cervical Cancer
 Abstract: Aim: We aimed to evaluate the sensitivity of 18F-Flourodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) in the detection of pelvic and paraaortic lymph node metastases of uterine cervical cancer.Material and Method: 32 female patients (mean age: 56.1±12.6) who underwent 18F-FDG PET/CT for preoperative staging of uterine cervical cancer between April 2009 and October 2013 were included to the study. Ethical committee approval was taken from Ankara University Medical Faculty Ethics Committee. All the patients had been performed trans-vaginal examination and diagnosed as uterine cervical cancer before 18F-FDG PET/CT. 18F-FDG PET/CT findings were compared with histopathological examination results. Sensitivity, specificity and accuracy of pelvic MRI and 18F-FDG PET/CT were calculated in the detection of pelvic and paraaortic lymph node metastases.Results: 18F-FDG uptake was seen in primary cervical lesions of all the patients. Mean SUV max of primary cervical lesions was calculated as 13.6±6.6 (range: 6.7-25). In 16 (50%) patients, 18F-FDG uptake was not seen in pelvic and paraaortic lymph nodes. In the remaining patients, 18F-FDG uptake was detected in pelvic nodes in all the patients (50%) and in paraaortic nodes in 6 (18%) patients. Mean SUV max of pelvic lymph nodes were calculated as 8.4±5.2 and of paraaortic lymph nodes 12.45±6.41. 18F-FDG uptake was detected in a total of 47 lymph node stations in 16 patients. Mean SUVmax of all lymph nodes were calculated as 8.9±5.83 (range: 2.6-21.9). According to 18F-FDG PET/CT findings, disease was upstaged from I to IV in 1 (3%) patient, II to III in 2 (6%) patients, III to IV in 1 (3%) patients and I to III in 2 (6%) patients, and down staged from III to I in 1 (3%) patient, respectively. In the patient-based analysis, 18F-FDG PET/CT was TP, TN, FP and FN in 14 (%44), 14 (44%), 2 (6%) and 2 (6%) patients, respectively. Patients based sensitivity; specificity and accuracy of 18F-FDG PET/CT were calculated as 87%, 87% and 87%, respectively. In the lesion-based analysis, 18F-FDG PET/CT was TP, FP, TN and FN in 30, 7, 37 and 5 lymph node stations, respectively. Lesion based sensitivity; specificity and accuracy of 18F-FDG PET/CT were calculated as 85%, 84% and 84%, respectively.Conclusion: 18F-FDG PET/CT is a reliable imaging tool with its high sensitivity and specificity in the pelvic and paraaortic lymph node staging of uterine cervical cancer. When performed in the preoperative staging it changes disease stage about in ¼ of patients. In combination of pelvic MRI, primary staging of primary cervical lesions and also pelvic/paraaortic lymph nodes can be done successfully
The Role of 18F-Flourodeoxyglucose (18F-FDG) Positron Emission Tomography/Computed Tomography (PET/CT) in Pelvic and Paraaortic Lymph Node Staging of Uterine Cervical Cancer
Aim: We aimed to evaluate the sensitivity of 18F-Flourodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) in the detection of pelvic and paraaortic lymph node metastases of uterine cervical cancer.  Material and Method: 32 female patients (mean age: 56.1±12.6) who underwent 18F-FDG PET/CT for preoperative staging of uterine cervical cancer between April 2009 and October 2013 were included to the study. Ethical committee approval was taken from Ankara University Medical Faculty Ethics Committee. All the patients had been performed trans-vaginal examination and diagnosed as uterine cervical cancer before 18F-FDG PET/CT. 18F-FDG PET/CT findings were compared with histopathological examination results. Sensitivity, specificity and accuracy of pelvic MRI and 18F-FDG PET/CT were calculated in the detection of pelvic and paraaortic lymph node metastases.  Results: 18F-FDG uptake was seen in primary cervical lesions of all the patients. Mean SUV max of primary cervical lesions was calculated as 13.6±6.6 (range: 6.7-25). In 16 (50%) patients, 18F-FDG uptake was not seen in pelvic and paraaortic lymph nodes. In the remaining patients, 18F-FDG uptake was detected in pelvic nodes in all the patients (50%) and in paraaortic nodes in 6 (18%) patients. Mean SUV max of pelvic lymph nodes were calculated as 8.4±5.2 and of paraaortic lymph nodes 12.45±6.41. 18F-FDG uptake was detected in a total of 47 lymph node stations in 16 patients. Mean SUVmax of all lymph nodes were calculated as 8.9±5.83 (range: 2.6-21.9). According to 18F-FDG PET/CT findings, disease was upstaged from I to IV in 1 (3%) patient, II to III in 2 (6%) patients, III to IV in 1 (3%) patients and I to III in 2 (6%) patients, and down staged from III to I in 1 (3%) patient, respectively. In the patient-based analysis, 18F-FDG PET/CT was TP, TN, FP and FN in 14 (%44), 14 (44%), 2 (6%) and 2 (6%) patients, respectively. Patients based sensitivity; specificity and accuracy of 18F-FDG PET/CT were calculated as 87%, 87% and 87%, respectively. In the lesion-based analysis, 18F-FDG PET/CT was TP, FP, TN and FN in 30, 7, 37 and 5 lymph node stations, respectively. Lesion based sensitivity; specificity and accuracy of 18F-FDG PET/CT were calculated as 85%, 84% and 84%, respectively.  Conclusion: 18F-FDG PET/CT is a reliable imaging tool with its high sensitivity and specificity in the pelvic and paraaortic lymph node staging of uterine cervical cancer. When performed in the preoperative staging it changes disease stage about in ¼ of patients. In combination of pelvic MRI, primary staging of primary cervical lesions and also pelvic/paraaortic lymph nodes can be done successfully
An interesting journey of an ingested needle: a case report and review of the literature on extra-abdominal migration of ingested Foreign bodies
Swallowed foreign bodies encounter a major problem especially in children, but fortunately they mostly do not cause any related complication and are easily passed with the stool. In this paper, an interesting journey of a needle is presented. A 20-year old female admitted to our emergency service after she had swallowed a sewing machine needle, which is initially observed in the stomach in the plain abdominal radiography. During the follow-up period, the needle traveled through bowels, and surprisingly was observed in the left lung on 10th day of the follow-up. It was removed with a thoracotomy and pneumotomy under the fluoroscopic guidance. The postoperative period was uneventful and the patient was discharged from the hospital on the day 5. We also review the literature on interesting extra-abdominal migrations of swallowing foreign bodies
European Position Paper on Rhinosinusitis and Nasal Polyps 2020
The European Position Paper on Rhinosinusitis and Nasal Polyps 2020 is the update of similar evidence based position papers published in 2005 and 2007 and 2012. The core objective of the EPOS2020 guideline is to provide revised, up-to-date and clear evidence-based recommendations and integrated care pathways in ARS and CRS. EPOS2020 provides an update on the literature published and studies undertaken in the eight years since the EPOS2012 position paper was published and addresses areas not extensively covered in EPOS2012 such as paediatric CRS and sinus surgery. EPOS2020 also involves new stakeholders, including pharmacists and patients, and addresses new target users who have become more involved in the management and treatment of rhinosinusitis since the publication of the last EPOS document, including pharmacists, nurses, specialised care givers and indeed patients themselves, who employ increasing self-management of their condition using over the counter treatments. The document provides suggestions for future research in this area and offers updated guidance for definitions and outcome measurements in research in different settings. EPOS2020 contains chapters on definitions and classification where we have defined a large number of terms and indicated preferred terms. A new classification of CRS into primary and secondary CRS and further division into localized and diffuse disease, based on anatomic distribution is proposed. There are extensive chapters on epidemiology and predisposing factors, inflammatory mechanisms, (differential) diagnosis of facial pain, allergic rhinitis, genetics, cystic fibrosis, aspirin exacerbated respiratory disease, immunodeficiencies, allergic fungal rhinosinusitis and the relationship between upper and lower airways. The chapters on paediatric acute and chronic rhinosinusitis are totally rewritten. All available evidence for the management of acute rhinosinusitis and chronic rhinosinusitis with or without nasal polyps in adults and children is systematically reviewed and integrated care pathways based on the evidence are proposed. Despite considerable increases in the amount of quality publications in recent years, a large number of practical clinical questions remain. It was agreed that the best way to address these was to conduct a Delphi exercise. The results have been integrated into the respective sections. Last but not least, advice for patients and pharmacists and a new list of research needs are included.Peer reviewe
Device Server for a Miniature Mobile Robot
This paper describes a device server for a miniature mobile robot. Generally, miniature robots have low-size memory and relatively slow microcontroller to realize complicated tasks. Therefore, a device server for small sized mobile robots is proposed with the intention of increasing their capabilities. The proposed software system runs on the microcontroller of the robot, and serves a collection of sensors and actuators over serial rf transceiver to authorized clients. The system has modularity and multi-tasking capability. The proposed system is implemented on a Z-80 microprocessor-controlled mobile robot. It is shown that proposed system is capable of serving one client and two processes
On Soft β-Open Sets and Soft β-Continuous Functions
We introduce the concepts soft β-interior and soft β-closure of a soft set in soft topological spaces. We also study soft β-continuous functions and discuss their relations with soft continuous and other weaker forms of soft continuous functions
Numerical analysis of confined and unconfined hydrogen turbulent flames
In this study, CFD modelling of confined and unconfined turbulent jet flames were carried out. Investigations were performed for different air:fuel ratios including stoichiometric conditions. Confined and unconfined combustions of hydrogen were investigated for different power inputs. As the combustion chamber is cylindrical and axisymmetrical, CFD modelling was made two dimensional and axisymmetrical
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