Cascading and modifying nonradiative energy transfer mechanisms in strong coupling region of plasmons and excitons in semiconductor quantum dots

Ankara : The Department of Electrical and Electronics Engineering and the Institute of Engineering and Sciences of Bilkent University, 2010.Thesis (Master's) -- Bilkent University, 2010.Includes bibliographical references leaves 57-60.Nonradiative energy transfer finds important applications in nanophotonics and nanobiotechnology including nanoscale optical waveguiding and biological nanosensors. Various fluorophores can take part in such energy transfer interactions in close proximity of each other. Their emission kinetics can be strongly modified and controlled as a result. For example, colloidal semiconductor quantum dots, also known as nanocrystals, have widely been shown to serve as donors and acceptors among themselves or with other fluorescent species to transfer excitation energy nonradiatively. In their close proximity, emission characteristics of such fluorophores can also be altered when coupled with plasmonic structures, e.g., metal nanoparticles. One favored result of these plasmon-exciton interactions is the emission enhancement. In principle it is possible to plasmon-couple acceptor-donor pairs of nonradiative energy transfer to modify their transfer rate. Such plasmon-mediated energy transfer has been demonstrated, where both acceptor-donor pairs are plasmoncoupled. In these cases, however, the resulting plasmon-exciton interactions are not controlled to take place either at the donor site or the acceptor site but at both of the sites. Therefore, it has previously not been possible to identify the coupled interactions. In this thesis, we propose and demonstrate cascaded plasmonic - nonradiative energy transfer interactions that are controlled by selectively plasmon-coupling either only the donor quantum dots or only the acceptor quantum dots. For that, we designed a novel self-assembly architecture of our hybrid layered systems of semiconductor nanocrystals and metal nanoparticles in a bottom-up fashion through precise spatial and spectral control. This scheme uniquely allowed for the ability to spatially control plasmonexciton interactions to take place either at the “start” site (donors) or “finish” site (acceptors) of the energy transfer. This control was achieved by placing the plasmonic layer in the right proximity of the donors (for strong donor-exciton plasmon-coupling) while sufficiently being far away from the acceptors (for weak acceptor-exciton plasmon-coupling), or vice versa. Here we comparatively studied and analyzed consequent modifications of quantum dot emission kinetics in response to both cases of plasmon-coupling to only the donors and to only the acceptors through steady-state and time-resolved photoluminescence measurements, along with their lifetime and rate calculations. Such cascaded energy transfer interactions in the strong exciton-plasmon coupling region hold great promise for innovative near-field photonic devices and biological tags. system.Akın, OnurM.S

Experimental Investigation of the Effect of Temperature on Friction Pressure Loss of Polymeric Drilling Fluid Through Vertical Concentric Annulus

Accurate estimation of annular friction pressure loss is necessary to perform drilling and well completion operations without lostcirculation, pipe sticking or more serious well control problems. Determination of friction pressure loss for Newtonian and non-Newtonianfluids has been investigated in several experimental and theoretical works by considering the effects of eccentricity, pipe rotation or pipegeometry. However, there is a gap in the studies about the temperature effect that is important especially in geothermal wells.This study experimentally investigated the effect of temperature on friction pressure loss through vertical concentric annulus by usingwater and the polymer based drilling fluid including Polyanionic Cellulose and Xanthan Gum. Experiments were conducted in flow loophaving 21-ft smooth and concentric annular test section (2.91 in ID casing x 1.85 in OD pipe).The effect of temperature on rheological model parameters, apparent viscosity, Reynolds number was examined. It was found thatconsistency index and yield point were more sensitive to change in temperature than flow behavior index. Also, apparent viscositydecreased exponentially with increasing temperature and this decrease was more obvious in low shear rate values. Then, according toReynolds number – temperature plot, earlier regime transition was observed with increasing temperature.As a result, increasing temperature caused the decrease in friction pressure loss, and temperature effect should be considered in futureexperimental and theoretical studies in order to estimate friction pressure loss in annuli precisely

Efficient hardware implementations of high throughput SHA-3 candidates keccak, luffa and blue midnight wish for single- and multi-message hashing

In November 2007 NIST announced that it would organize the SHA-3 competition to select a new cryptographic hash function family by 2012. In the selection process, hardware performances of the candidates will play an important role. Our analysis of previously proposed hardware implementations shows that three SHA-3 candidate algorithms can provide superior performance in hardware: Keccak, Luffa and Blue Midnight Wish (BMW). In this paper, we provide efficient and fast hardware implementations of these three algorithms. Considering both single- and multi-message hashing applications with an emphasis on both speed and efficiency, our work presents more comprehensive analysis of their hardware performances by providing different performance figures for different target devices. To our best knowledge, this is the first work that provides a comparative analysis of SHA-3 candidates in multi-message applications. We discover that BMW algorithm can provide much higher throughput than previously reported if used in multi-message hashing. We also show that better utilization of resources can increase speed via different configurations. We implement our designs using Verilog HDL, and map to both ASIC and FPGA devices (Spartan3, Virtex2, and Virtex 4) to give a better comparison with those in the literature. We report total area, maximum frequency, maximum throughput and throughput/area of the designs for all target devices. Given that the selection process for SHA3 is still open; our results will be instrumental to evaluate the hardware performance of the candidates

Geospatial technologies for physical planning: Bridging the gap between earth science and planning

The application of geospatial information technologies has increased recently due to increase in data sources from the earth sciences. The systematic data collection, storage and processing together with data transformation require geospatial information technologies. Rapidly developing computer technology has become an effective tool in design and physical planning in international platforms. Especially, the availability of geospatial information technologies (remote sensing, GIS, spatial models and GPS) for diverse disciplines and the capability of these technologies in data conversion from two dimensions to the three dimensions provide great efficiency. Thus, this study explores how digital technologies are reshaping physical planning and design. While the potential of digital technologies is well documented within physical planning and visualization, its application within practice is far less understood. This paper highlights the role of the geospatial information technologies in encouraging a new planning and design logic that moves from the privileging of the visual to a focus on processes of formation, bridging the interface of the earth science and physical planning

Farklı Laboratuvarlarca Dökümü Yapılmış Tek Parça Döküm Parsiyel Protezlerde Kullanılan Metal Alaşımların Sitotoksisite Yönünden Değerlendirilmesi

Amaç: Bu araştırmanın amacı farklı laboratuvarlarca dökümü yapılmış tek parça döküm parsiyel protezlerde kullanılan metal alaşımların değerlendirilmesidir.sitotoksisite yönünden Gereç ve Yöntem: Sivas’ta faaliyet gösteren 4 farklı laboratuvardan, kumlama ve kumlama+cila işlemi uygulanmış 1 mm çapında,1.5 mm kalınlıkta disk şeklindeki metal örnekler elde edildi. Hazırlanan metal örnekler etilen oksit gazıyla sterilize edildi ve L929 fibroblast hücre serisi kullanlarak elde edilen kültüre yerleştirildi. Agar overley testi kullanılarak sitotoksisitenin belirlenmesinde ISO 2009 yılı 10993-5 numaralı protokolü takip edildi.Bulgular: Hücrelerin lizis miktarna göre yapılan laboratuvardan 3 tanesinden elde edilen örnekler sitotoksik bulunmamışken, 1 tanesinden elde edilen bulunmuştur. Ayrıca çalışmamızda tüm gruplarda kumlama ve kumlama+cila arasında sitotoksite açısından fark bulunamamıştı

Prevalence of mastocytosis and hymenoptera venom allergy in the United States

Background : Mastocytosis is a risk factor for hymenoptera venom anaphylaxis (HVA). Current guidelines recommend measuring tryptase in HVA patients and that those with mastocytosis pursue lifelong venom immunotherapy (VIT). Available data on HVA and mastocytosis largely derives from European single-center studies and the prevalence of HVA with and without mastocytosis in the United States (US) is unknown. Objective : We sought to determine the prevalence of HVA and mastocytosis in the US using an insurance claims database and evaluate the impact of mastocytosis on VIT in HVA patients in a US cohort. Methods :The IBM Watson Database, consisting of insurance claims from approximately 27 million US patients in 2018, was queried to identify patients with HVA and/or mastocytosis. Further, a retrospective study of 161 patients undergoing VIT between 2015 – 2018 at the University of Michigan (U-M) was conducted. Results :In the IBM Watson Database, the prevalence of HVA was 167 per 100,000 (0.167%) and the prevalence of mastocytosis 10 per 100,000 (0.010%) overall and 97 per 100,000 (0.097%) among those with HVA. Mastocytosis showed a 9.7-fold increase among HVA patients versus the general population. In the U-M cohort, 2.6% of VIT patients had mastocytosis. Tryptase level did not correlate with venom reaction severity but was higher in patients with systemic VIT reactions. Conclusions :We observed a lower US HVA prevalence than previously reported. Mastocytosis was more common in US HVA patients, though at lower rates than previously reported. In VIT patients there was no correlation between tryptase level and reaction severity. Key words :Tryptasevenom allergyvenom immunotherapyanaphylaxismastocytosismast cell activation syndromemast cell disease Abbreviations Hymenoptera venom allergyHVAUnited StatesUSVenom immunotherapyVITMast Cell DiseaseMCDAmerican Academy of Allergy, Asthma, and ImmunologyWOS:000717466600002Scopus - Affiliation ID: 60105072PMID: 33895259Science Citation Index ExpandedQ1ArticleUluslararası işbirliği ile yapılan - EVETKasım2021YÖK - 2021-2

Triglyceride-glucose index levels in patients with congenital hypogonadotropic hypogonadism and the relationship with endothelial dysfunction and insulin resistance

Introduction: The risk of cardiometabolic diseases is increased in patients with hypogonadism. The triglyceride-glucose (TyG) index is a novel surrogate marker of insulin resistance and is associated with cardiovascular diseases. We investigated the TyG index levels and the relationship with endothelial dysfunction and insulin resistance in patients with congenital hypogonadotropic hypogonadism (CHH). Material and methods: A total of 98 patients with CHH (mean age 21.66 ± 1.99 years) and 98 healthy control subjects (mean age 21.69 ± 1.21 years) were enrolled. The demographic parameters, TyG index, asymmetric dimethylarginine (ADMA), high-sensitivity C-reactive protein (hs-CRP), and homeostatic model assessment of insulin resistance (HOMA-IR) levels were measured for all participants. Results: The patients had higher waist circumference (p < 0.001), triglycerides (p = 0.001), insulin (p = 0.003), HOMA-IR (p = 0.002), ADMA (p < 0.001), and TyG index (p < 0.001) levels and lower HDL-C (p = 0.044) and total testosterone (p < 0.001) levels compared to healthy control subjects. TyG index levels significantly correlated with the ADMA (r = 0.31, p = 0.003) and HOMA-IR (r = 0.32, p < 0.001) levels. TyG index was also determinant of HOMA-IR levels (ß = 0.20, p = 0.018). Conclusion: The results of the present study show that patients with CHH had increased TyG index levels. Also, the TyG index is independently associated with insulin resistance in patients with CHH. Long-term follow-up studies are warranted to find out the role of the TyG index in determining cardiometabolic risk in patients with hypogonadism.

Dijagnostička točnost sastojaka mlijeka kod dijagnostike gravidnosti u krava srednje i kasne laktacije

The aims of this study were to establish a cut-off point by evaluating the usability of the somatic cell count (SCC) and milk components (fat, fat-free dry matter (FFDM), protein, lactose, freezing point, electrical conductivity and pH) to observe the pregnancy status, and to determine the practical usage of these parameters as diagnostic biomarker of pregnancy status. In the present study, primiparous Holstein cows (n=133) were included in the mid and late lactation. Milk samples were collected in sterile tubes for SCC and milk components analysis. In each lactation period, SCC, milk yield and milk component parameters were analysed by Student\u27s t test according to pregnancy status. Receiver operating characteristic curves were used to determine the predictive threshold using SCC and milk component parameters to discriminate between pregnant and non-pregnant cows. SCC levels were similar for all cows in the mid and late-lactation. In the mid lactation, FFDM, protein, lactose and electrical conductivity were higher and milk yield, fat, freezing point and pH were lower in pregnant cows (p<0.05). In the late lactation, FFDM, protein, lactose and electrical conductivity were significantly higher and milk yield, fat and pH were significantly lower in pregnant cows (p<0.05). Furthermore, fat, FFDM, protein, lactose, freezing point, electrical conductivity, and pH were the best predictors for pregnancy diagnosis in mid-lactating cows with the AUC values of 0.840, 0.768, 0.780, 0.772, 0.693, 0.792, and 0.901 respectively. Furthermore, fat, FFDM, protein, lactose, electrical conductivity, and pH could be useful diagnostic tools for pregnancy determination in late lactating cows with the AUC values of 0.869, 0.684, 0.661, 0.689, 0.756, and 0.841 respectively. In conclusion, the milk components could be used as rapid, easily accessible, and inexpensive markers for the evaluation of the diagnosis of pregnancy status in primiparous Holstein cows.Ciljevi ove studije bili su utvrditi granične vrijednosti procjenom mogućnosti upotrebe broja somatskih stanica (SCC) i pojedinih fizikalno-kemijskih parametara mlijeka (udio masti, bezmasne suhe tvari (FFDM), proteina, laktoze, točke zamrzavanja, električne vodljivosti i pH) za promatranje statusa gravidnosti kao i u svrhu korištenja navedenih parametara kao bioloških markera u dijagnozi statusa gravidnosti. U ovu su studiju bile uključene prvotelke holstein pasmine (n=133) u srednjoj i kasnoj laktaciji. Uzorci mlijeka sakupljani su u sterilne epruvete za analizu SCC i fizikalno-kemijskih parametara. U svakom razdoblju laktacije, SCC, prinos mlijeka i fizikalno-kemijski parametri analizirani su Student t-testom u odnosu na status gravidnosti. Za određivanje prediktivnog praga korištene su krivulje odnosa specifičnosti i osjetljivosti klasifikatora (ROC), korištenjem SCC i fizikalno-kemijskih parametara mlijeka za razlikovanje gravidnih i negravidnih krava. Za sve krave u srednjoj i kasnoj laktaciji razine SCC bile su slične. Sredinom laktacije, FFDM, udjeli proteina i laktoze te električna vodljivost bili su viši, a prinos mlijeka, udio masti, točka ledišta i pH bili su niži u gravidnih krava (p<0,05). U kasnoj laktaciji, FFDM, udjeli proteina i laktoze te električna vodljivost bili su značajno viši, a prinos mlijeka, udio masti i pH bili su značajno niži u gravidnih krava (p<0,05). Udjeli masti, proteina i laktoze, FFDM, točka ledišta, električna vodljivost i pH bili su najbolji prediktori za dijagnozu gravidnosti kod krava u srednjoj laktaciji s vrijednostima površina ispod ROC krivulje (AUC) 0,840, 0,768, 0,780, 0,772, 0,693, 0,792 i 0,901. Udjeli masti, proteina i laktoze, FFDM, električna vodljivost i pH mogu biti korisni dijagnostički alati za određivanje gravidnosti kod krava u kasnoj laktaciji s AUC vrijednostima 0,869, 0,684, 0,661, 0,689, 0,756 i 0,841. Zaključno, komponente mlijeka mogu se koristiti kao brzi, lako dostupni i jeftini markeri za procjenu dijagnoze statusa gravidnosti kod prvotelki holstein krava

Clinical characteristics and growth hormone treatment in patients with prader-willi syndrome

Objective: To investigate clinical characteristics and response to growth hormone (GH) treatment in patients with Prader-Willi syndrome (PWS) in Turkey. Methods: The data of 52 PWS patients from ten centers was retrospectively analyzed. A nation-wide, web-based data system was used for data collection. Demographic, clinical, genetic, and laboratory data and follow-up information of the patients were evaluated. Results: The median age of patients at presentation was 1.5 years, and 50% were females. Genetic analysis showed microdeletion in 69.2%, uniparental disomy in 11.5%, imprinting defect in 1.9% and methylation abnormality in 17.3%. Hypotonia (55.7%), feeding difficulties (36.5%) and obesity (30.7%) were the most common complaints. Cryptorchidism and micropenis were present in 69.2% and 15.3% of males, respectively. At presentation, 25% had short stature, 44.2% were obese, 9.6% were overweight and 17.3% were underweight. Median age of obese patients was significantly higher than underweight patients. Central hypothyroidism and adrenal insufficiency were present in 30.7% and 4.7%, respectively. Hypogonadism was present in 75% at normal age of puberty. GH treatment was started in 40% at a mean age of 4.7±2.7 years. After two years of GH treatment, a significant increase in height SDS was observed. However, body mass index (BMI) standard deviation (SDS) remained unchanged. Conclusion: The most frequent complaints were hypotonia and feeding difficulty at first presentation. Obesity was the initial finding in 44.2%. GH treatment was started in less than half of the patients. While GH treatment significantly increased height SDS, BMI SDS remained unchanged, possibly due to the relatively older age at GH start. Keywords: Prader-Willi syndrome, endocrine dysfunction, growth hormone treatment, body compositio

Outcomes of high-risk breast lesions diagnosed using image-guided core needle biopsy: results from a multicenter retrospective study

PURPOSEThe clinical management of high-risk lesions using image-guided biopsy is challenging. This study aimed to evaluate the rates at which such lesions were upgraded to malignancy and identify possible predictive factors for upgrading high-risk lesions.METHODSThis retrospective multicenter analysis included 1.343 patients diagnosed with high-risk lesions using an image-guided core needle or vacuum-assisted biopsy (VAB). Only patients managed using an excisional biopsy or with at least one year of documented radiological follow-up were included. For each, the Breast Imaging Reporting and Data System (BI-RADS) category, number of samples, needle thickness, and lesion size were correlated with malignancy upgrade rates in different histologic subtypes. Pearson’s chi-squared test, the Fisher–Freeman–Halton test, and Fisher’s exact test were used for the statistical analyses.RESULTSThe overall upgrade rate was 20.6%, with the highest rates in the subtypes of intraductal papilloma (IP) with atypia (44.7%; 55/123), followed by atypical ductal hyperplasia (ADH) (38.4%; 144/375), lobular neoplasia (LN) (12.7%; 7/55), papilloma without atypia (9.4%; 58/611), flat epithelial atypia (FEA) (8.7%; 10/114), and radial scars (RSs) (4.6%; 3/65). There was a significant relationship between the upgrade rate and BI-RADS category, number of samples, and lesion size Lesion size was the most predictive factor for an upgrade in all subtypes.CONCLUSIONADH and atypical IP showed considerable upgrade rates to malignancy, requiring surgical excision. The LN, IP without atypia, pure FEA, and RS subtypes showed lower malignancy rates when the BI-RADS category was lower and in smaller lesions that had been adequately sampled using VAB. After being discussed in a multidisciplinary meeting, these cases could be managed with follow-up instead of excision