Wos Kapalı Erişimli Yayınlar

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Adrenergic receptor behaviors of mesenchymal stem cells obtained from different tissue sources and the effect of the receptor blockade on differentiation
(2021) Maytalman, Erkan; Alizadeh Yegani, Arash; Kozanoglu, Ilknur; Aksu, Fazilet; 0000-0002-5268-1210; 34323168; AAE-1241-2021
In this study, it was aimed to analyze behavioral changes of adrenergic receptors (ARs) in first three passages and osteogenic/adipogenic differentiation of mesenchymal stem cells (MSCs) derived from placenta fetal membrane (FM) and bone marrow (BM). It was also aimed to evaluate effects of receptor blockade on differentiation. We obtained first three passages of MSCs from placenta and BM samples. For cell identification, the cells were analyzed by flow cytometry using CD34, CD45 and CD3, CD105 antibodies in each passage. The effects of propranolol and phenoxybenzamine at incremental doses were analyzed by MTT. In addition, cell cultures were separately maintained with the blockers or without after second passage. After each passage and differentiation, alpha 1A, alpha 1B, alpha 2A, alpha 2B, beta 1, beta 2, beta 3 AR-mRNA expressions analyzed by RT-qPCR technique. BMP6 and PPARG mRNA expressions only after differentiation and passage 3 were analyzed. A microscopic examination was also performed. Our results showed that AR expression behaviors were different in MSCs obtained from different tissue sources. In particular, alpha(1A)-AR and alpha(2A)-AR were expressed with considerably high coefficients in differentiation under blocker effect in BM-derived MSCs. No such coefficients were observed in any group of placental MSCs. In addition, it was found that the blockers stimulated adipogenesis in BM-derived MSCs during osteogenic differentiation. MSCs exhibit protein expressions that vary according to source of tissue and differentiation. Given that MSCs from different sources are used for repair and modulation, our study makes implications of this variable expression intriguing in the clinical practice.
After a Workshop on the Novel Antivirals for Treatment of Hepatitis C Virus Infection (4-6 December 2015, Istanbul)
(2016) Tekin, Suda; Aygen, Bilgehan; Aydin, Mehtap; Simsek, Funda
Age estimation in Turkish children and young adolescents using fourth cervical vertebra
(2020) Gulsahi, Ayse; Cehreli, Sevi Burcak; Galic, Ivan; Ferrante, Luigi; Cameriere, Roberto; 31915966
This study aimed to test radiographic projections of the posterior and anterior sides of the C4 vertebral body for age estimation in a cross-sectional sample of Turkish children and adolescents from the Baskent University Faculty of Dentistry. A sample of 232 x-rays from individuals aged between 5 and 15 years (101 boys and 131 girls) was analysed to investigate the correlation of age and changes in the projection ratio of the anterior and posterior sides of the body of the fourth cervical vertebra (Vba) in lateral cephalograms. The Normal Bayesian Calibration (NBC) model for age estimation was used to assess the relationship between Vba and age. The intra-observer repeatability and inter-observer agreement were 0.95 and 0.94, respectively. Age distribution gradually increased as Vba increased up to 14 years in both sexes. The difference between chronological and estimated ages did not increase with the increase in age. Calibration distributions of the dataset by the evaluation of Vba suggested mean absolute errors (MAEs) of 0.879 years and 0.906 years (mean interquartile ranges (MIQRs) 1.290 and 1.435 years)) in boys and girls, respectively. The biases of the estimates (beta(ERR)) were 0.013 and 0.027 for boys and girls, respectively. In conclusion, the NBC method on Vba variable appears to be suitable for age estimation in Turkish children and adolescents.
Age- and Gender-Related Variability in Nasal Tip Support
(2020) Koycu, Alper; Erol, Ozan; Buyuklu, Fuat Adnan; Jafarov, Sabuhi; Berker, Sinem; 0000-0003-1528-0036; 0000-0003-1290-3509; 0000-0002-7302-4199; 31834522; W-5941-2018; AAF-3650-2021; AAI-8044-2021
Background The age at which nasal tip support changes start to occur is unknown. Evaluation of nasal tip support is difficult, especially as the ideal nasal tip support pressure remains elusive. The aim of this study is to determine the nasal tip support pressure alterations relative to age and sex. Objectives The aim of this study is to determine the changers in resistance of the nasal tip support in relation to age and sex. Methods This prospective clinical study was conducted between January and April 2019 at a tertiary health facility. Nasal tip resistances were measured in four different age-groups (20-29, 30-39, 40-64, and > 65 years) with a digital Newton meter. A total of 159 patients with a minimum of 36 patients per group were included in the study. Nasal tip resistance measurements were compared among nasal tip displacement distances of 2, 3, and 4 mm, focusing on age and sex. Results The nasal tip resistance of the 20-29 age-group was significantly higher at 2, 3, and 4 mm nasal tip displacement distances, when compared with the 30-39 and 40-64 age-groups, whereas compared to the > 65 years group, it was significantly higher at 3 and 4 mm nasal tip displacement distances (p < 0.005). Nasal tip resistance of males was found to be significantly higher than that of females, at 3 and 4 mm nasal tip displacement distances (p < 0.001). Conclusions Nasal tip resistance is higher in males and universally decreases significantly after 30 years of age while remaining constant at later ages. Therefore, surgeons should prefer nasal tip resistance increasing techniques in the rhinoplasty operations that are performed on patients even from early years of age, in order to maintain and strengthen the nasal tip resistance.
Airfoil-slat arrangement model design for wind turbines in fuzzy environment
(2020) Atalay, Kumru Didem; Dengiz, Berna; Yavuz, Tahir; Koc, Emre; Ic, Yusuf Tansel
In this study, a multi-element wind turbine blade that consists of NACA 6411 and NACA 4412 leading-edge slat design is investigated computationally. Optimum design parameters of the slatted wind turbine blade leading to maximum value of C-L/C-D related to the turbine power are obtained. In the optimization process, a new fuzzy logic linear programming methodology integrating with fuzzy linear regression and 2D CFD analysis is proposed. The aerodynamic characteristics of the slatted blade are computed by using Incompressible Navier-Stokes equations and k-omega turbulence modeling. Results are compared with the results of linear programming method and direct search optimization method. The computational results reveal that the proposed methodology for performance optimization is more effective than other methods to obtain high-performance value of the C-L/C-D. The maximum value of the C-L/C-D is obtained as 25.1 leading the maximum efficiency of 0.52.
Altered pulmonary functions due to biomass smoke in a rural population of Turkish women: a descriptive study
(2018) Ozsancak Ugurlu, Aylin; Balcan, Baran; Akan, Selcuk; Ceyhan, Berrin; 30246655; A-4721-2018
Introduction: Wood or other organic sources of fuel are used as source of energy for heating or cooking particularly in developing countries. The aim of the current study was to evaluate the association between biomass exposure time and parameters of pulmonary function tests. Materials and Methods: Four hundred twenty-four consecutive women who lived and exposed to biomass smoke in a small province in Eastern Turkey were involved. This study was performed with women who had come to pulmonology out-patient clinic with symptom of dyspnea. Results: The independent variables assessed in the study patients were age, BMI, starting age of cooking, hours per day and weeks per month spent cooking, and cooking years; the dependent variables were PFT parameters. Ninety-two (21.6%) patients had an obstructive PFT pattern. Sixty-seven (73%) of these patients were classified as GOLD 2 and 25 (27%) patients were classified as GOLD 3. Seventy-five (17.6 %) of the patients had restrictive lung disease; 54 (72%) of these patients were found to have a mild and 21 (27%) had a moderate restrictive pattern. Increased number of years in cooking and to start cooking at younger ages were a risk factors for the development of obstructive and restrictive disease. There was a statistically significant and negative correlation between increased number of years and the value of FEV1 (r=-0.917; p=<0.001), FEV1/FVC (r=-0.739; p<0.001), and FVC (r=-0.906; p<0.001). The median time of cooking required was 23 years for the development of obstruction, and 25 years for restriction, respectively. Conclusion: Cumulative biomass exposure time is associated with impairment in PFT parameters; results in both obstructive and restrictive lung disease. Biomass exposure is a public health problem and pre-cautions should be taken in order to prevent impaired pulmonary functions.
An Alternative Low-Cost Solution for Tracking Laboratory Animals
(2020) Kiziltan, Erhan; Aydin, Leyla; 0000-0001-6029-3835; AAD-6090-2021
Objectives: Monitoring animal behavior under various conditions can provide important information on their neuropsychological status, including learning, memory, and cognitive activity. Several commercial tracking systems are available, but they may be too expensive for low-budget projects. This study developed an alternative solution for automated animal tracking in behavioral experiments. Methods: The proposed system was designed to analyze a set of images sampled from a recorded video file in chronological order. The instantaneous location of the animal in each image frame was defined automatically, using a feature-extraction algorithm. Distances traveled were calculated using the coordinates of the successive instantaneous locations. The algorithm was tested using two arenas: the Morris water maze and open field test. The calculated measures were compared with those obtained manually. The internal consistency of the dataset was checked using Cronbach's alpha. The accuracy of the results was evaluated using the paired samples t-test and Pearson correlation, with the level of statistical significance set at p<0.01. Results: A statistical comparison of the distances traveled, which were derived from the coordinates of successive locations, did not differ significantly between the manual and automatic methods (r=0.954 and p=0.792 for the Morris water maze; r=0.996 and p=0.024 for the open field test). Conclusions: These results suggest that the algorithm is reliable and valid for estimating coordinates and may serve as a high-resolution tool for animal behavior experiments. We intend to make this software freely available to interested readers and to open feedback channels for further development.
Analysis of Bcl-2, PTEN, p53, and Ki-67 expressions in endometrial cancer arising from endometrial polyp
(2019) Karakas, L. A.; Tohma, Y. A.; Kuscu, E.; Ozen, O.; Ayhan, A.
Objective: To compare the expression of the proliferation marker Ki-67, the antiapoptotic protein Bcl-2, and the tumor suppressor genes p53 and PTEN between endometrial cancer arising from endometrial polyp and benign endometrial polyps. Materials and Methods: The study was performed retrospectively in 40 patients treated at the present institution between 2006-2011. A total of 20 cases that had endometrial cancer arising from endometrial polyp that met study criteria were included consecutively in the study. For each malign case, one case that had a benign endometrial polyp diagnosed at hysterectomy specimen was included in the study. Results: The Ki-67 score was significantly higher in endometrial cancer arising from endometrial polyp group in comparison to the benign polyps (p < 0.05). However, the Bcl-2 expression was significantly lower in the endometrial cancer arising from endometrial polyp when compared to the benign polyps (p < 0.05). PTEN and p53 expressions were not different between groups (p > 0.05). in patients with endometrial cancer, Ki-67, Bcl-2, PTEN, and p53 expressions were not different among histological type, stage, grade, myometrial invasion, polyp size, and lymphovascular space invasion, with an exception of p53. p53 expression was significantly increased in higher grade tumors (p < 0.05). Conclusion: The results of the present study indicate that there is an inhibition of apoptosis and a decrease in proliferation in benign endometrial polyps. Possibly, at carcinogenesis step of endometrial cancer developed from benign polyp, other additional mutations cause a reverse effect and they increase proliferation and prevent the apoptosis inhibition.
Analysis of Probiotic Bacteria Genomes: Comparison of CRISPR/Cas Systems and Spacer Acquisition Diversity
(2021) Ilikkan, Ozge Kahraman; 0000-0001-5843-6868; 35068602; Q-9641-2019
Clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated (Cas) genes constitute an adaptive (acquired) defense system of bacteria and archaea. Here 72 probiotic bacteria genomes were investigated in terms of the presence of CRISPR/Cas systems and phage/plasmid invaders through spacer analysis. 49 CRISPR/Cas systems were detected within probiotic strains, namely,17 type II-A, 10 type I-C, 8 type I-E, 5 Type I-U (I-G), 4 type III-A, 2 type I-B, 1 type I-A, 1 type IV-B, and 1 type II-C. The predicted target of spacers was determined in 25 strains and consequently, three different spacer and target patterns were revealed. The diversity of CRISPR spacers provides insight and understanding to determine strain-specific invaders of probiotic bacteria as well as their relationships between strains. CRISPR systems were clarified in many studies for genomic characterization. However, recently, endogenous genome editing with CRISPR has provided an approach for various genome editing projects. Thus, in the future, producing strain-specific phage-resistant starter cultures or probiotics by endogenous genome editing methods according to phage/plasmid survey can be utilized for industrial and pharmaceutical applications. Therefore, this study intended a comprehensive investigation of CRISPR systems of probiotic bacteria.
Analysis of the IR-Raman Modes and the Heat Capacity Near the alpha-Inc-beta Transitions in Quartz
(2021) Yurtseven, H.; Gunay, E.; Karacali, H.; Ates, S.
This study gives our analysis for the temperature dependence of the infrared frequency and the integrated intensity of the 695 cm(-1) mode near the alpha-beta transition at 847.5 K and the temperature dependence of the Raman scattering cross section of the 355 cm(-1) mode near the beta-INC (incommensurate) transition which occurs within a small temperature (similar to 1.3 K) interval in relation to the order parameter in quartz. Both analyses are performed according to a power-law formula for the order parameter Q with the critical index beta using the experimental data from the literature. We also analyze the temperature dependence of the heat capacity C p according to the renormalization-group expression including first-order corrections to scaling term close to the alpha-INC-beta transitions in quartz by using the literature data. From our analyses, values of the critical exponent beta for the frequency and the integrated intensity of the 695 cm(-1) infrared mode and for the Raman scattering cross section of the 355 cm(-1) mode as a measure of the order parameter, are extracted. From the analysis of C p , the values of the critical exponent alpha are also extracted. Additionally, by means of scaling relations the critical exponent gamma of the isothermal compressibility kappa T and the renormalized components ( beta R , alpha R and gamma R ) are predicted for the alpha-INC-beta transitions in quartz. Our analyses given here indicate that weakly first-order transition occurs from the alpha phase to the incommensurate (INC) phase, which changes to the nearly second-order transition to the beta phase with increasing temperature in quartz, as also observed experimentally.
Analysis of the manufacturing flexibility parameters with effective performance metrics: a new interactive approach based on modified TOPSIS-Taguchi method
(2022) Ic, Yusuf Tansel; Sasmaz, Turgut; Yurdakul, Mustafa; Dengiz, Berna; 0000-0001-9274-7467; AGE-3003-2022
Flexibility is one of the most important strategy parameters to achieve a long-term successful performance for a manufacturing company. Studies in the literature aim to operate a manufacturing system at optimum levels of flexibility parameters under its own manufacturing environment. This study aims to present an interactive analysis framework based on TOPSIS and Taguchi parameter design principles for investigating the effects of different levels of flexibility parameters on the performance of a flexible manufacturing cell (FMC). The main performance metric used in this study is manufacturing lead time. Other important metrics to evaluate quality control and inspection policies are also investigated in this study. To conclude, a combined model of an interactive approach based on TOPSIS and Taguchi methods are used to assess the effectiveness of the flexibility parameters for a FMC.
Analysis of The Performance of A Solar Air Heater With Different Configurations: Effect of Fins And Turbulators
(2022) Erol, Ozgur
Solar air heaters are simple tools used to harvest the energy of the sun. The main objective of the solar air heater design is to get the highest thermal energy from the sun. In order to do this different kinds of fins and turbulators are placed in the flow channel of the solar air heater, which also affects the flow characteristic of the working fluid. In this study, the performance of two different configurations, a turbulator placed at the bottom of the channel and a longitudinal rectangular fin placed on the absorber plate, are investigated using different performance parameters. These parameters are the thermal efficiency, rational exergy management method (REMM) efficiency, flow work, and the temperature distribution on the absorber plate. According to the results, both of the test cases have nearly the same performance, which is higher than the flat solar air except the flow work. When the heat gain per unit flow work is investigated, it can be said that turbulator configuration is the best choice among the configurations that are investigated.
Analysis of the Robustness of the Operational Performance Using a Combined Model of the Design of Experiment and Goal Programming Approaches for a Flexible Manufacturing Cell
(2023) Ic, Yusuf Tansel; Yurdakul, Mustafa; Dengiz, Berna; Sasmaz, Turgut
A combined model of a 2(k) design of experiment (DOE) and goal programming (GP) approaches is presented to determine optimum levels of input variables and analyze their robustness for a multiobjective performance of a flexible manufacturing cell (FMC) in this study. Two main performance metrics, namely, manufacturing lead time (MLT) and surface roughness (SR), are considered performance outputs for the FMC. Machine sequence, robot speed, tool type, and material type are selected as the four input variables on the input side of the proposed model. The study shows that even with a limited number of experiments, one can determine optimum input levels for the multiobjective performance of the FMC and determine their robustness.
An analysis of Turkey's solar PV auction scheme: What can Turkey learn from Brazil and South Africa?
(2021) Sirin, Selahattin Murat; Sevindik, Irem
As global investments continue in renewable energy technologies, investment costs have declined significantly. Meanwhile, many governments have shifted from pre-set renewable support schemes to auction schemes in order to introduce competition in price setting. Turkey has initiated Renewable Energy Resource Zone (RERZ) auctions to promote solar photovoltaic (PV) and wind technologies. We examine the first of these auctions, Solar PV RERZ, which has ambitious targets in terms of increasing solar PV capacity and enhancing domestic competence in solar technologies. Despite the auction being hailed as a success in terms of low prices, we utilize the Levelized Cost of Electricity generation (LCOE) analysis to demonstrate that the project is vulnerable to macroeconomic shocks and financial risks. Model results show that the capacity factor is the most prominent factor in costs, and 10% change in the capacity factor affects the LCOE about the same rate. Investment cost and interest rate are the other major factors affecting the LCOE. Based on these results, we make recommendations by discussing how Turkey can improve its auction design by incorporating some of the elements used by Brazil and South Africa.
Angiopoietin-1, Angiopoietin-2, and Periostin Levels in Children with Recurrent Wheeze
(2018) Koksal, Burcu Tahire; Aydin, Beril Ozdemir; Tekindal, Agah; Ozbek, Ozlem Yilmaz
Background: Recurrent wheeze (RW) is frequent in preschool children. Wheezing phenotypes, asthma predictive index (API), and modified API (mAPI) have been described for clinical purposes. Our aim was to examine whether inflammatory markers including serum angiopoietin (Ang)-1, Ang-2, and periostin levels differ according to wheezing phenotypes and mAPI. Materials and Methods: Ninety-eight children who were <4 years of age with history of at least 4 episodes of wheezing during the past 12 months and 51 age-matched healthy controls were included in the study. Children with RW were classified according to wheezing phenotypes as episodic viral wheeze or multitrigger wheeze, and positive or negative mAPI. Blood for Ang-1, Ang-2, and periostin levels was drawn during wheezing episode-free periods. Results: Atopic children with RW (31.4 +/- 34.4 ng/mL) demonstrated higher serum Ang-1 levels than nonatopic children (16.5 +/- 13.8 ng/mL) with RW (P = 0.03). When we compared children according to wheezing phenotypes, we could not find any difference in serum Ang-1, Ang-2, and periostin levels between groups. Children with positive mAPI showed similar Ang-1, Ang-2, and periostin levels with children having negative API and healthy children. Conclusions: We have found higher serum Ang-1 levels in atopic children with RW, and this result might be explained by increased inflammation. The evidence was not strong enough to associate serum Ang-1, Ang-2, or periostin and asthma in preschool children with RW. However, Ang-1 can be a candidate for investigating its role in predicting atopic children and diagnosing atopic childhood asthma.
Anocutaneous Reflex Revisited: How Valuable Is Its Determination in Children with Spina Bifida? A Descriptive Study in A Cohort of 217 Patients
(2022) Ozel, Kerem; Canmemis, Arzu; Goknar, Nilufer; Candan, Cengiz; Alizada, Orkhan; Alatas, Ibrahim; 35147971
AIM: To determine the clinical value of anocutaneous reflex (AR) in children with neurogenic bladder due to spina bifida (SB). MATERIAL and METHODS: Patients who were diagnosed with SB were prospectively evaluated; moreover, AR and bulbocavernous reflex were examined. Patients were divided into those with and without AR. Age, gender, diagnosis, ventriculoperitoneal shunt presence, symptomatic urinary tract infections, leg movements, clean intermittent catheterization and anticholinergic therapy, lesion level, urodynamic detrusor, and sphincter activity were evaluated. Chi-square test and univariate regression analysis were done. The AR value was evaluated by two by two contingency table. RESULTS: This study evaluated 217 patients (109 boys and 108 girls). AR was present and absent in 53 and 164 patients, respectively. Anticholinergic therapy was necessary in 37.7% and 23.8% of patients with and without AR (p=0.015), respectively. Patients with AR had higher lesion level (p=0.005), more detrusor overactivity, and less detrusor underactivity (p=0.007). Less detrusor sphincter dyssynergia (DSD) was noted in patients with AR (p=0.029). AR specificity was 83%, and positive predictive value in predicting detrusor overactivity and DSD was 76% and 80, respectively. CONCLUSION: AR determination is a valuable and simple tool in neurogenic bladder. This report delineates the clinical significance of this reflex and is the largest cohort describing this significance. This simple examination should not be skipped in the initial evaluation and follow-up of these patients
Antecedents of Nurse Burnout During a Pandemic: Managerial Way Out
(2022) Basar, Ufuk; Dogan, Aysun; Ertugrul, Bekir
The aim of this research is to uncover whether nurses' fear of contracting Coronavirus Disease 2019 (COVID-19) has resulted in stress-related presenteeism and burnout, and whether perceived organisational support is effective in dealing with both nurses' fear of contracting COVID-19 and its undesired consequences. For this purpose, a cross-sectional and descriptive research has been conducted. The data are collected from 513 nurses working in Ankara, Turkey, through a questionnaire survey. Independent samples t-test, one-way analysis of variance test and partial least squares structural equation modelling technique are employed to analyse the data. Findings indicate that nurses fear infection and experience stress-related presenteeism and burnout considerably. However, they perceive slightly inadequate level of organisational support. Fear of infection has resulted in stress-related presenteeism and burnout. Stress-related presenteeism has mediated the relationship between fear of infection and burnout. Perceived organisational support has negatively related to fear of infection and its negative consequences. In this research, to our knowledge, for the first time, the burnout, stress-related presenteeism, fear of infection and perceived organisational support levels of nurses are compared according to the pandemic-related criteria. Besides, the mediating role of nurses' stress-related presenteeism between their fear of contracting COVID-19 and burnout is discovered.
Antecedents of tourist food consumption: food choice motives of foreign tourists in Turkey
(2023) Ekizler, Huseyin; Oksuz, Merve; Durmus, Beril; Shipman, Zehra Dilistan; 0000-0003-2470-7919
Culinary or gastronomy tourism has become a rising issue nowadays. People want to discover new flavour while travelling. Food consumption is the combination of one's cultural, social, psychological and sensory acceptance factors and it is a very complex decision-making process. Food consumption is also associated with motivational factors which are mood, health, sensory appeal, familiarity, convenience, price and natural content. The antecedents of tourist food consumption and food choice motives of foreign tourists in Istanbul were examined. The results show that sensory appeal, mood, natural content, health content and convenience had positive and direct connection with tourist food consumption intentions. There is no statistically significant evidence to support the associations of familiarity and price with the tourist food consumption intentions.
Anterior Spinal Artery Syndrome: Rare Precedented Reason of Postoperative Plegia After Spinal Deformity Surgery: Report of 2 Cases
(2020) Bahadir, Sinan; Nabi, Vugar; Adhikari, Prashant; Ayhan, Selim; Acaroglu, Emre; 0000-0003-0153-3012; 32502625; U-5409-2018
BACKGROUND: Complications in spinal deformity surgery vary from insignificant to severe. Apart from direct mechanical insult, ischemia can also cause spinal cord injury. Ischemic injury may be detected during surgery or may manifest itself postoperatively. We present 2 cases of anterior spinal artery syndrome. CASE DESCRIPTION: In the first case, a 12-year-old girl developed anterior spinal artery syndrome resulting in total quadriplegia 8 hours after spinal deformity surgery. She was treated with a steroid, immunoglobulin, and lowmolecular-weight heparin. She showed complete recovery at 1 year postoperatively both clinically and radiographically. In the second case, a 62-yearold woman experienced sudden loss of motor evoked potentials intraoperatively during dural tear repair after sagittal and coronal alignment was established. The paraplegic patient was diagnosed with anterior spinal artery syndrome at the thoracic level postoperatively. She was treated with a steroid and heparin. At 1 year postoperatively, she has gained much of her strength and has myelomalacia in her spinal cord. CONCLUSIONS: Anterior spinal artery syndrome is a serious condition with a generally poor prognosis. Though treatment should be directed at the underlying cause, the best strategy is to prevent it from occurring. Peroperative blood pressure control, intraoperative neuromonitoring, avoidance from mechanical stress during surgery, and close neurologic and hemodynamic monitorization postoperatively should be performed.
Antibody Immobilization Techniques in Mass Sensitive Immunosensor: Enhanced Sensitivity through Limited Mass Load
(2022) Kirali, Kubra; Brimo, Nura; Serdaroglu, Dilek Cokeliler; https://orcid.org/0000-0002-3053-2169; https://orcid.org/0000-0002-9604-263X; https://orcid.org/0000-0001-8645-9047
Background: Biosensors are analytical devices that include a sample-delivery approach between a biological recognition element and a transducer required to convert the physicochemical change produced from the interaction of biological molecule-receptor interaction into a signal. The immunosensor is a special type of biosensor that includes an antibody as a biorecognition element to detect analytes as antigens. In mass sensitive sensors, antigen-antibody interactions can be specified by measuring the frequency change and the most commonly knowns are the surface acoustic wave, bulk acoustic wave, quartz crystal microbalance and microcantilevers. Methods: Different methods for antibody immobilization, including functionalization of the transducer surface with specific groups, have been reported for antibody immobilization. This stage affects the limit of detection and overall performance. In this review, perspectives on immobilization strategies of mass sensitive immunosensors according to transducer types will be presented. The choice of immobilization methods and their impact on performance in terms of capture molecule loading, orientation and signal improvement will also be discussed. Results: One of the most critical points during the configuration of the biorecognition layer is to improve the sensitivity. Therefore, we initially focused on comparisons of the antibody immobilization strategies in the biorecognition layer in terms of mass load level and high sensitivity. Conclusion: The lack of significant data on the mass accumulations up to the functionalization and antibody immobilization steps, which are the basis of immusensor production, has been identified. However, mass sensitive immunosensors have the potential to become more common and effective analytical devices for many application areas.