37 research outputs found

    Modeling and fabrication of electrostatically actuated diaphragms for on-chip valving of MEMS-compatible microfluidic systems

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    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

    Utjecaj dodatka praha sluzi chia sjemenki (Salvia hispanica L.) na neka fizikalno-kemijska i reološka svojstva ayrana

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    In this study, chia seed mucilage powder (MP) was added into ayran drinks at different ratios (0.05, 0.10 and 0.15%, w/v), and its effect on physicochemical, rheological, microbiological and sensory properties of ayran drinks was determined during 10 days of storage at 4±1 °C. MP addition did not influence their major chemical composition significantly (p>0.05). Increasing MP ratio in drinks decreased the colour L* values of drinks while increasing their colour a* and b* values. Addition of 0.05, 0.10 and 0.15% MP reduced serum separation values of drinks by 25, 67 and 83%, respectively. The apparent viscosity value of control samples was 103.20 cP and increased to 134.25, 185.35 and 223.38 cP in ayran drinks with 0.05, 0.10 and 0.15% MP, respectively. The obtained results indicated that chia seed MP up to 0.05% can be used in ayran drink production to reduce serum separation and improve viscosity without any adverse effect on sensory liking scores.U ovom istraživanju, prah sluzi chia sjemenki (MP) dodan je u ayran napitke u različitim omjerima (0,05, 0,10 i 0,15 %, w/v) te je ispitivan njegov učinak na fizikalno-kemijska, reološka, mikrobiološka i senzorska svojstva ayran napitaka tijekom 10 dana skladištenja na 4±1 °C. Dodatak MP nije značajno utjecao na njihov glavni kemijski sastav (p>0,05). Povećanje omjera MP u pićima smanjilo je L* vrijednosti boje pića dok je povećalo njihove a* i b* vrijednosti boje. Dodatak 0,05, 0,10 i 0,15 % MP smanjio je vrijednosti sinereze napitaka za 25, 67 odnosno 83 %. Prividna viskoznost kontrolnih uzoraka bila je 103,20 cP i porasla je na 134,25, 185,35 i 223,38 cP u ayran napicima s 0,05, 0,10 i 0,15 % MP. Rezultati su pokazali da se MP chia sjemenki do 0,05 % može koristiti u proizvodnji ayrana, kako bi se smanjila sinereza i poboljšala viskoznost bez ikakvih negativnih učinaka na senzorska svojstva

    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

    Type 1 Regulations

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    I developed a PID controller through Matlab for a DC motor speed.Also I summerized development of Type 1 regulation.BSc/BAElectrical Engineerin

    Increasing the Stimulation Dose of rFSH in Unexpected Poor Responders Is Not Associated with Better IVF Outcome

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    The aim of this retrospective study is to determine whether increasing the stimulation dose of rFSH in unexpected poor responders is associated with better in vitro fertilization (IVF) outcome or not. A total of forty eligible women who fulfilled our definition of poor responders and who did not achieve an ongoing pregnancy in the first cycle and returned for a second higher rFSH dose IVF cycle with a long-agonist protocol were included to the study. The first low-dose cycles and the second high-dose cycles were compared to each other. Main outcome measures of the study were duration of stimulation, number of follicles, number of oocytes retrieved, number of embryos, and E2 level on day of hCG injection. There were no significant differences in duration of stimulation, number of follicles, number of oocytes retrieved, number of embryos, and E2 level on day of hCG injection between the first low- and second high-dose cycles. Daily dose and total dose of rFSH were significantly higher in the second high-dose cycles. Increasing the dose of rFSH in a second stimulation cycle after first unsuccessful treatment cycle will add only to the cost and discomfort of the treatment and might adversely affect pregnancy rates

    Removal of Antimony(III) and Antimony(V) from water samples through water-soluble polymer-enhanced ultrafiltration

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    Addressing antimony (Sb) contamination, which is caused by the use of Sb compounds in various industries, is crucial. This study aims to compare two different Sb removal mechanisms: ion exchange and chelation. There-fore, two different water-soluble polymers-glycidyl methacrylate-N-methyl-D-glucamine and poly 2-(acryl-oyloxy)ethyl trimethylammonium chloride-were synthesized and used to remove Sb(III) and Sb(V) using the polymer-enhanced ultrafiltration (PEUF) method. The removal of Sb(III) was pH-dependent and extremely difficult at a pH of 1.2. However, when the pH of the solution was increased to 11, the Sb(III) removal rate increased to 77%. The Sb(III) removal rate was 28% at an Sb(III):polymer mole ratio of 1:5, which increased to 77% at a mole ratio of 1:20. Sb(III) removal was discovered to be unaffected by the low concentrations of Na+, K+, Ca2+, and Mg2+ ions in the solution, maintaining a Sb(III) removal rate of 77%. The test parameters showed different characteristics for Sb(V) removal. Increasing the pH of the solution from 1 to 9 correspondingly increased the removal rate from 0% to 45%, but increasing it further to 11 decreased the removal rate to 14%. The removal rate of Sb(V) was 67% at a Sb(V):polymer mole ratio of 1:60. Sb(V) removal was discovered to be unaffected by low concentrations of SO42-, NO3-, and PO43- anions in the solution. However, notably, the Sb(V) removal rate decreased from 67% to 58% in the presence of Cl ions. The results demonstrate that Sb removal via chelation was more effective than by ion exchange, and it remained unaffected by the presence of interfering ions.Scientific Research Projects Coordination Office of Ege University [FGA -2019-20716]; Ege University Planning and Monitoring Coordination of Organizational Development and Directorate of Library and DocumentationThis study is supported by the Scientific Research Projects Coordination Office of Ege University (project number: FGA -2019-20716) . We are grateful to Ege University Planning and Monitoring Coordination of Organizational Development and Directorate of Library and Documentation for their support in editing and proofreading this paper

    The Effects of Six-Month L-Thyroxine Treatment on Cognitive Functions and Event-Related Brain Potentials in Children with Subclinical Hypothyroidism

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    Objective: The aim of this study was to investigate the cognitive status of children with subclinical hypothyroidism (SH) before and after L-thyroxine (L-T4) treatment using event-related potentials (ERPs) and neuropsychological tests. Methods: This prospective study was conducted on a series of 20 children with mild SH (free T4 normal and thyroid-stimulating hormone level within 5-10 mu IU/L) who underwent clinical and cognitive assessment before L-T4 treatment and 6 months afterwards. The recordings of ERPs were done at the time of diagnosis and after 6 months of euthyroid state. Neuropsychiatric tests for attention, perception, close and remote memory were performed on all patients and on the control group which consisted of 20 healthy children of normal intelligence. Results: While pretreatment verbal memory (VM) and verbal recall (VR) scores of the SH group were significantly lower than those of the control group (p=0.004 and 0.012, respectively), no significant differences between the post-treatment and control groups were found in these scores after 6 months of L-T4 treatment. Post-treatment VM and VR scores were significantly higher than the pretreatment scores in the SH group (p=0.008 and p=0.0001). There were no significant differences between the pre- and post-treatment values of electrophysiological evaluation in N1, P2, P3 latencies or P3 amplitude (p>0.05), although there was a significant decrease in N2 latency in the post-treatment group (p=0.03). Conclusion: SH affects cognition in children and L-T4 replacement therapy leads to normalization of cognitive functions. Neuropsychological tests can be used as complementary measures in the evaluation of children with SH. Determining the association between ERPs and SH would contribute to the comprehensive evaluation of these children

    Removal of boron from aqueous solution by modified cellulose

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    Cellulose is a promising alternative material as a sorbent for the removal of pollutants. The availability of hydroxyl groups on cellulose allows for the application of various modification reactions for the development of novel sorbents with different functional groups. In this work, a cellulose sorbent modified with N-methyl-glucamine was prepared and tested for the removal of boron. A batch adsorption process was used to further explore the boron sorption kinetics, isotherms, thermodynamics, mechanism, and reuse of the prepared sorbent. It was found that the optimum sorbent dose for boron removal was 0.2 g/25 mL. Moreover, the initial pH of the solution was found to affect the removal rate and was found to be >= 4. The sorption of boron reached equilibrium within 60 min. The maximum sorption capacity was calculated to be 4.7 mg B/g sorbent. The sorption process was found to be exothermic and the negative value of increment S in the range of 30-60 degrees C is related to a decrease in randomness at the solid/solution interface during the sorption of boron on the sorbent. The sorption/regeneration experiments have shown that the removal rate of the sorbent remains the same over 5 cycles.Ege University [FLP-2020-22167]This study is supported by Ege University Scientific Research Projects Coordination Unit (Project Number: FLP-2020-22167).; Ege Universitesi,FLP-2020-22167,Ozgur Ara

    The prognostic value of gene expressions of ERCC1 and RRM1 in non-small cell lung cancer.

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    49th Annual Meeting of the American-Society-of-Clinical-Oncology (ASCO) -- MAY 31-JUN 04, 2013 -- Chicago, ILWOS: 000335419604603…Amer Soc Clin Onco

    Effect of chia (Salvia hispanica L.) seed mucilage powder on some physicochemical and rheological properties of ayran drinks

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    In this study, chia seed mucilage powder (MP) was added into ayran drinks at different ratios (0.05, 0.10 and 0.15%, w/v), and its effect on physicochemical, rheological, microbiological and sensory properties of ayran drinks was determined during 10 days of storage at 4±1 °C. MP addition did not influence their major chemical composition significantly (p>0.05). Increasing MP ratio in drinks decreased the colour L* values of drinks while increasing their colour a* and b* values. Addition of 0.05, 0.10 and 0.15% MP reduced serum separation values of drinks by 25, 67 and 83%, respectively. The apparent viscosity value of control samples was 103.20 cP and increased to 134.25, 185.35 and 223.38 cP in ayran drinks with 0.05, 0.10 and 0.15% MP, respectively. The obtained results indicated that chia seed MP up to 0.05% can be used in ayran drink production to reduce serum separation and improve viscosity without any adverse effect on sensory liking scores
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