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Dna Nanopores as Artificial Membrane Channels for Bioprotonics
No full textBiological membrane channels mediate information exchange between cells and facilitate molecular recognition. While tuning the shape and function of membrane channels for precision molecular sensing via de-novo routes is complex, an even more significant challenge is interfacing membrane channels with electronic devices for signal readout, which results in low efficiency of information transfer - one of the major barriers to the continued development of high-performance bioelectronic devices. To this end, we integrate membrane spanning DNA nanopores with bioprotonic contacts to create programmable, modular, and efficient artificial ion-channel interfaces. Here we show that cholesterol modified DNA nanopores spontaneously and with remarkable affinity span the lipid bilayer formed over the planar bio-protonic electrode surface and mediate proton transport across the bilayer. Using the ability to easily modify DNA nanostructures, we illustrate that this bioprotonic device can be programmed for electronic recognition of biomolecular signals such as presence of Streptavidin and the cardiac biomarker B-type natriuretic peptide, without modifying the biomolecules. We anticipate this robust interface will allow facile electronic measurement and quantification of biomolecules in a multiplexed manner. © 2023, Springer Nature Limited.National Science Foundation, NSF: 20-518; University of California, UC: 22-601; University of Washington, UW; Türkiye Bilimsel ve Teknolojik Araştırma Kurumu, TÜBİTAK: 2214-AL.L., S.M., Y.P., B.D., J.S., M.P.A., E.E.O., A.G. and M.R. acknowledge the main financial support of the National Science Foundation (NSF 20-518). L.L. thanks to Dr. Tom Yuzvinsky in BSOE at University of California, Santa Cruz for his help about the fabrication of bioprotonic devices. B.D. acknowledges the support of the Hyak supercomputer system at the University of Washington and financial support from the TUBITAK International Doctoral Research Fellowship program (TUBITAK 2214-A). J.S. acknowledges the support of the University of California, Santa Cruz Research Experiences for Undergraduates (REU) in sustainable materials, which is supported by the National Science Foundation (NSF 22-601)
Recent Advances in Endoscopic Management of Gastric Neoplasms
No full textThe development and clinical application of new diagnostic endoscopic technologies such as endoscopic ultrasonography with biopsy, magnification endoscopy, and narrow-band imaging, more recently supplemented by artificial intelligence, have enabled wider recognition and detection of various gastric neoplasms including early gastric cancer (EGC) and subepithelial tumors, such as gastrointestinal stromal tumors and neuroendocrine tumors. Over the last decade, the evolution of novel advanced therapeutic endoscopic techniques, such as endoscopic mucosal resection, endoscopic submucosal dissection, endoscopic full-thickness resection, and submucosal tunneling endoscopic resection, along with the advent of a broad array of endoscopic accessories, has provided a promising and yet less invasive strategy for treating gastric neoplasms with the advantage of a reduced need for gastric surgery. Thus, the management algorithms of various gastric tumors in a defined subset of the patient population at low risk of lymph node metastasis and amenable to endoscopic resection, may require revision considering upcoming data given the high success rate of en bloc resection by experienced endoscopists. Moreover, endoscopic surveillance protocols for precancerous gastric lesions will continue to be refined by systematic reviews and meta-analyses of further research. However, the lack of familiarity with subtle endoscopic changes associated with EGC, as well as longer procedural time, evolving resection techniques and tools, a steep learning curve of such high-risk procedures, and lack of coding are issues that do not appeal to many gastroenterologists in the field. This review summarizes recent advances in the endoscopic management of gastric neoplasms, with special emphasis on diagnostic and therapeutic methods and their future prospects
Latis Malzemelerin Enerji Emme ve Ezilme Davranışlarının Statik ve Dinamik Yüklemeler Altında İncelenmesi
No full textLattice materials have a number of superior properties compared to dense solids, such as low weight, high strength and high energy absorption capacity. Because of these superior properties, lattice materials are widely used as structural components in various industries, including machinery, construction, aerospace, automotive, biomedical and personal protective equipment. In recent years, advancements in additive manufacturing technologies have made it possible to produce lattice materials with complex geometries that cannot be produced with traditional production methods. Furthermore, with the development of technology, the need for materials with higher energy absorption capacity has increased, making the study of energy absorption and crushing behavior of lattice materials with different unit cell geometries an important research area. However, although the research on such materials is growing rapidly, it is predominantly limited to hexagonal and other classical lattice materials. In this study, the in-plane energy absorption and crushing behaviors of five new isotropic lattice materials (C Tekoğlu. Truss-lattice materials consisting of mixed polygons, 2023. World Intellectual Property Organization, Application Number: PCT/TR2022/051154.) with superior mechanical properties, namely Mixed Hexagonal-2 Triangular, Hierarchical-3 Triangular, Modified Kagome-I, Modified Kagome-II and Modified Kagome-III, were investigated by finite element analyses. The results were compared with analyzes of Hexagonal and Triangular-Triangular lattices. By observing crushing behaviors of lattice matertials, three different deformation modes were defined according to the crushing velocity: quasi-static, transition and dynamic mode. The energy absorption and crushing behaviors were compared using five different metrics that are often used in the literature: densification strain, peak crushing stress, mean plateau stress, energy absoprtion and ideality parameter. Modified Kagome-II lattice together with Triangular-Triangular lattice structure have the lowest energy absorption capacity in quasi-static and transition modes. The Mixed Hexagonal-2 Triangular, Hierarchical-3 Triangular, Modified Kagome-I, and Modified Kagome-III lattice structures exhibited, compared to the Hexagonal lattice, approximately 19.6%, 20.2%, 19%, and 27% higher energy absorption capacities in static mode, and 17%, 11.6%, 10.8%, and 29.5% higher energy absorption capacities in transition mode, respectively. In dynamic mode, the hexagonal lattice has the lowest energy absorption capacity. The Mixed Hexagonal-2 Triangular, Hierarchical-3 Triangular, Triangular-Trianglar, Modified Kagome-I, Modified Kagome-II, and Modified Kagome-III lattice structures have higher energy absorption capacities in dynamic mode compared to the Hexagonal lattice, 22.5%, 5%, 5.1%, 9.9%, 10.8%, and 26.1% higher energy absorption capacities, respectively. The lattice with the highest energy absorption capacity in all deformation modes is the Modified Kagome-III. In terms of the ideality parameter, the Hierarchical-3 Triangular lattice structure exhibited the closest behavior to an ideal energy absorber. Overall, this study clearly reveals that the lattices studied in the thesis are important competitors to Hexagonal and other classical lattice materials, which are frequently used in energy absorption and crushing applications.Latis malzemeler, yoğun katılara kıyasla, hafiflik, yüksek mukavemet ve yüksek enerji emme kapasitesi gibi bir dizi üstün özelliklere sahiptir. Bu üstün özelliklerinden dolayı latis malzemeler makine, inşaat, havacılık, uzay, otomotiv, biyomedikal ve kişisel koruyucu ekipmanlar dâhil olmak üzere çeşitli endüstrilerde yapısal bileşenler olarak yaygın şekilde kullanılmaktadır. Eklemeli imalat teknolojilerinde son yıllarda yaşanan ilerlemeler, geleneksel üretim metotları ile üretilemeyen geometriye sahip latis malzemelerin üretilebilir hale gelmesini mümkün kılmıştır. Bununla birlikte, teknolojinin gelişmesiyle daha yüksek enerji emme kapasitesine sahip malzemelere olan ihtiyaçların artması, farklı birim hücre geometrilerine sahip latis malzemelerin enerji emme ve ezilme davranışlarının incelenmesini önemli bir araştırma konusu haline getirmiştir. Ancak, bu tür malzemeler üzerine yapılan çalışmalar, günden güne artmakla birlikte, genellikle Altıgen ve diğer klasik latis malzemelerle sınırlıdır. Bu çalışmada, üstün mekanik özelliklere sahip, Karma Altıgen-2 Üçgen, Hiyerarşik-3 Üçgen, Değiştirilmiş Kagome-I, Değiştirilmiş Kagome-II ve Değiştirilmiş Kagome-III adında beş yeni izotropik latis malzemenin (C Tekoğlu. Truss-lattice materials consisting of mixed polygons, 2023. World Intellectual Property Organization, Başvuru numarası:PCT/TR2022/051154.) düzlem içi enerji emme ve ezilme davranışları sonlu elemanlar analizleri ile incelenmiştir. Sonuçlar, Altıgen ve Üçgen-Üçgen latislere ait analizlerle karşılaştırılmıştır. Latislerin ezilme davranışları gözlemlenerek yükleme hızına göre 3 farklı deformasyon modu tanımlanmıştır: sanki statik, geçiş ve dinamik mod. Enerji emme ve ezilme davranışları, literatürde sıklıkla kullanılan beş farklı metrik kullanılarak karşılaştırılmıştır: yoğunlaşma birim şekil değiştirmesi, tepe çarpışma gerilmesi, ortalama plato gerilmesi, toplam enerji emilimi ve ideallik parametresi. Sanki statik ve geçiş modlarında Üçgen-Üçgen latis ile birlikte Değiştirilmiş Kagome-II latis yapısı en düşük enerji emme kapasitesine sahiptirler. Karma Altıgen-2 Üçgen, Hiyerarşik-3 Üçgen, Değiştirilmiş Kagome-I ve Değiştirilmiş Kagome-III latis yapıları, Altıgen latise kıyasla sanki statik modda sırasıyla, %19.6, %20.2, %19 ve %27, geçiş modunda ise sırasıyla, %17, %11.6, %10.8 ve %29.5 daha yüksek enerji emme kapasitesi sergilemiştir. Dinamik modda ise Altıgen latis en düşük enerji emme kapasitesine sahiptir. Karma Altıgen-2 Üçgen, Hiyerarşik-3 Üçgen, Üçgen- Üçgen, Değiştirilmiş Kagome-I, Değiştirilmiş Kagome-II ve Değiştirilmiş Kagome-III latis yapıları dinamik modda sırasıyla, Altıgen latise kıyasla, %22.5, %5, %5.1, %9.9, %10.8 ve %26.1 daha yüksek enerji emme kapasitelerine sahiptir. Tüm deformasyon modlarında en yüksek enerji emme kapasitesine sahip latis Değiştirilmiş Kagome-III'tür. İdeallik parametresi açısından ise Hiyerarşik-3 Üçgen latis yapısı ideal bir enerji emiciye en yakın davranışı sergilemiştir. Bu çalışma, tez kapsamında incelenen latislerin enerji emme ve ezilme uygulamalarında sıklıkla kullanılan Altıgen ve diğer klasik latis malzemelere önemli rakipler olduklarını açıkça ortaya koymaktadır
Gender Wage Determinants: Theory and Evidence
No full textOver the past century, women's roles in society and their labor market participation have changed significantly. Even though there have been big steps toward equal pay for men and women in the workplace, the gender pay gap still exists in many places. Policymakers in certain states of the U.S. have enacted "gender pay discrimination" bans to combat the pervasive discrimination against women. These bans make it illegal to pay individuals differently based on their gender. The main goal of this thesis is to find out what causes the pay gap between men and women in the U.S. by focusing on how state bans affect the wages of women workers by using administrative data between the years 1997 and 2020. In this regard, based on the Solovian growth model, we first develop a theoretical framework with a steady state solution to investigate the long run determinants of the gender pay gap using an empirical pay gap model. Our theoretical model signifies the importance of the "share difference", defined as the difference between the shares of women and men in the total labor force. At state level, we test the importance of "share difference" in reducing the gender pay gap using state fixed effects and quantile regression techniques. While our findings highlight the significance of labor force participation, the effect is larger at higher quantiles. Regarding the gender pay discrimination bans, we conclude that the passage of a law against gender discrimination decreases the gender gap if the wage gap is narrow. At the household level, using the difference-in-differences (DID) technique and the human capital wage equation, we find that gender pay discrimination bans significantly increase women's wages, especially among the high-paid workers at the top of the wage distribution.Son yüzyılda, kadınların toplumdaki rolleri ve iş gücüne katılımları önemli ölçüde değişmiştir. Birçok alanda erkekler ve kadınlar için eşit ücret yönünde büyük adımlar atılmış olmasına rağmen, cinsiyetler arasındaki ücret farkı hala varlığını sürdürmektedir. Amerika Birleşik Devletleri'nin birtakım eyaletlerinde politika yapıcılar, kadınlar aleyhindeki ayrımcılığı önlemek için "cinsiyete dayalı ücret ayrımcılığını yasaklayan" mevzuatları çıkarmıştır. Bu mevzuatlar, cinsiyete göre farklı ödeme yapılmasını yasa dışı hale getirmektedir. Bu tezin temel amacı, Amerika Birleşik Devletleri'nin 1997 ve 2020 yılları arasındaki idari verilerini kullanarak erkekler ve kadınlar arasındaki ücret farkının nedenlerini, eyalet mevzuatlarının kadın işçilerin ücretleri üzerindeki etkisine odaklanarak bulmaktır. Bu bağlamda, öncelikle, Solovian büyüme modeline dayalı ampirik bir ücret farkı modeli kullanarak cinsiyetler arası ücret farkının uzun vadedeki belirleyicilerini soruşturmak üzere durağan durum çözümüne sahip teorik bir çerçeve geliştirilmiştir. Teorik çerçeve, kadınların ve erkeklerin iş gücündeki toplam payları arasındaki fark olarak tanımlanan "pay farkının" önemini vurgulamaktadır. Eyaletler düzeyinde, eyalet sabit etkiler ve kantil regresyon teknikleri kullanılarak "pay farkının" cinsiyetler arası ücret farkını azaltmadaki önemi test edilmiştir. Bulgular kadınların işgücüne katılımının önemini vurgularken, ücret farkının yüksek olduğu kantillerde etkinin daha büyük olduğunu ortaya koymuştur. Cinsiyete dayalı ücret ayrımcılığını yasaklarına gelindiğinde, ücret farkının az olduğu durumlarda cinsiyetler arası ücret ayrımcılığına karşı bir mevzuat çıkarmanın ücret farkını azalttığı sonucuna varılmıştır. Hanehalkı düzeyinde farkların farkı tekniği ve beşerî sermaye ücret denklemi kullanılarak cinsiyete dayalı ücret ayrımcılığına yönelik yasakların yürürlüğe girmesinin kadınların ücretlerini artırdığı bulunmuştur. Bu yasakların en çok, ücret dağılımının en tepesindeki yüksek ücretli işçiler arasındaki kadınlar üzerinde etkili olduğu gözlemlenmiştir
Centralized Bargaining With Pre-Donation in a Vertically Related Industry
No full textThis paper studies the incentives for, and the welfare effects of, pre-donation in a vertically related industry where two downstream firms that produce a homogenous good jointly bargain, using the generalized Nash rule, with an upstream firm over a linear input price before they engage in Cournot competition. We theoretically show that the downstream industry has no incentive to make any pre-donation and this is irrespective of its bargaining power and also irrespective of whether it is a monopoly or a symmetric or asymmetric duopoly. Also, irrespective of the said structures of the downstream industry, we show computationally that (i) the upstream firm finds to make unilateral pre-donation optimal if and only if its bargaining power is sufficiently small and (ii) its optimal pre-donation (whenever positive) always yields Pareto welfare gains
Real-Time Detection of Acromegaly From Facial Images With Artificial Intelligence
No full textOBJECTIVE: Despite improvements in diagnostic methods, acromegaly is still a late-diagnosed disease. In this study, it was aimed to automatically recognize acromegaly disease from facial images by using deep learning methods and to facilitate the detection of the disease. DESIGN: Cross-sectional, single-centre study. METHODS: The study included 77 acromegaly (52.56 ± 11.74, 34 males/43 females) patients and 71 healthy controls (48.47 ± 8.91, 39 males/32 females), considering gender and age compatibility. At the time of the photography, 56/77 (73%) of the acromegaly patients were in remission. Normalized images were obtained by scaling, aligning, and cropping video frames. Three architectures named ResNet50, DenseNet121, and InceptionV3 were used for the transfer learning-based convolutional neural network (CNN) model developed to classify face images as "Healthy" or "Acromegaly". Additionally, we trained and integrated these CNN machine learning methods to create an Ensemble Method (EM) for facial detection of acromegaly. RESULTS: The positive predictive values obtained for acromegaly with the ResNet50, DenseNet121, InceptionV3, and EM were calculated as 0.958, 0.965, 0.962, and 0.997, respectively. The average sensitivity, specificity, precision, and correlation coefficient values calculated for each of the ResNet50, DenseNet121, and InceptionV3 models are quite close. On the other hand, EM outperformed these three CNN architectures and provided the best overall performance in terms of sensitivity, specificity, accuracy, and precision as 0.997, 0.997, 0.997, and 0.998, respectively. CONCLUSIONS: The present study provided evidence that the proposed AcroEnsemble Model might detect acromegaly from facial images with high performance. This highlights that artificial intelligence programs are promising methods for detecting acromegaly in the future. © The Author(s) 2023. Published by Oxford University Press on behalf of (ESE) European Society of Endocrinology. All rights reserved. For permissions, please e-mail: [email protected]
Lmca Aneurysm and a Fistula Resulting With a Giant Extracardiac Aneurysm
No full textA 54-year-old, asymptomatic, disease-free female patient was operated for an incidentally detected left main coronary artery aneurysm (CAA) associated with fistula to a giant aneurysm associated with the right atrium (RA). The patient had an extremely rare left main CAA and a fistula connection of a giant aneurysm connecting to the RA
Identification of a Lumped Element Modeled Ring Shaped Structure Via Peak Pickıng Method
No full textASME International Design Engineering Technical Conferences / 43rd Annual Computers and Information in Engineering Conference (IDETC-CIE) / 35th Conference on Mechanical Vibration and Sound (VIB) -- AUG 20-23 -- 2023 -- Boston -- MAThis paper presents an application of a well-known modal system identification method (i.e., Peak Picking Method) on ring shaped structures with imbalances in terms of natural frequency and damping ratio mismatches, in-silico. To the best of our knowledge, the application of this method to ring shaped structures is novel in the literature. The system is modeled at secondary vibration pattern (n=2) via zero dimension lumped element modeling approach. Hence the model has two orthogonal modes (i.e., 2-DOF) with coupling terms of natural frequency and time constant mismatch azimuth angles in-between. Natural frequencies and damping ratios in modal coordinates are estimated using Peak Picking Method based on Real and Imaginary parts of Direct and Cross Frequency Response Functions (FRFs). For this purpose, sine-sweep force signals are applied to the model and displacement values of the both modes are collected. Additionally, eigenvalue decomposition method is utilized to obtain the system characteristic as well as to derive system parameters and coupling terms in generalized coordinates. This identification approach is applied to model with varying quality factors (ranging between 2,5001,000,000), natural frequencies (ranging between 500-3501 Hz) with numerous natural frequency differences of 0.2 Hz, 1 Hz, and 5 Hz, and different natural frequency azimuth mismatch angle values of pi/6 and pi/12 while keeping the time constant azimuth mismatch angle value at pi/8 for performance evaluations. Results show that Peak Picking Method can accurately estimate the natural frequencies in all scenarios, on the other hand damping ratio estimations present higher errors in lower quality factors. Also, both azimuth mismatch angle estimations always converge to the highest value given, which is a shortcoming of this method.This study is supported by Roketsan Inc.Amer Soc Mech Engineers, Design Engn Div,Amer Soc Mech Engineers, Comp ; Informat Engn Div, Tech Comm Micro ; Nano SystRoketsan Inc