Search

In the present work, new and efficient Cobalt Titanium Boride (Co-Ti-B) catalysts were developed for catalytic hydrolysis reaction of alkaline NaBH4 solution. Hydrogen generation rate was measured using the ternary Co-Ti-B catalyst as a function of different Ti concentration, solution temperature, NaBH4 concentration, and NaOH (a base-stabilizer) concentration. The performance of the system was analyzed from thermodynamic points of view and compared with the pristine Co-B catalyst. In addition to high catalytic efficiency, the catalyst must also comprise important features like high stability in severe conditions and should have high tolerance against deactivation. The highest hydrogen generation rate was obtained with 5% Ti/(Ti + Co) molar ratio, and for this catalyst the optimum fuel concentration was identified as 5 wt.% NaBH4 with 5 wt.% NaOH. (C) Copyright 2015, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.

ABS TRACT Objective: Pre o pe ra ti ve pre pa ra ti on of hyperth yro id pa ti ents is ex tre mely im por tant to avo id comp li ca ti ons du e to se ve re thyro to xi co sis during surgery. We in ves ti ga ted the ef fects of lu gol’s so lu ti on (LS) with or wit ho ut thi o na mi des in the ra pid pre pa ra ti on of the patients for thy ro id sur gery and com pa red the ef fect of LS in pa ti ents with Gra ves’ di se a se (GD) and to xic mul ti no du lar go i ter (TMNG). Material and Met hods: Da ta we re col lec ted ret ros pec ti vely from 44 pa ti ents with hyperth yro i dism who we re fol lo wed up in our cli nic. Twenty-two pa ti ents with GD, 19 pa ti ents with TMNG and three pa ti ents with so li tary to xic ade no ma we re en rol led in to the study. To res to re euth yro i dism be fo re sur gery, 27 pa ti ents we re tre a ted with LS (gro up 1) whi le 17 pa ti ents re ce i ved LS and thi o na mi des (gro up 2). Re sults: Me an da ily to tal do sa ge of LS and du ra ti on of tre at ment to res to re euth yro i dism we re not sta tis ti cally dif fe rent bet we en gro ups 1 and 2. When the two tre at ment gro ups we re com pa red, the re was no sig ni fi cant dif fe ren ce in ba se li ne pa ra me ters and per cen ta ge of chan ges of se rum fT4 and fT3 le vels. Du ra ti on of LS tre at ment and do sa ges of LS and thi o na mi des we re al so si mi lar in pa ti ents with GD and TMNG. Per cen ta ge of chan ges in se rum fT4 and fT3 le vels af ter LS tre at ment we re not sta tis ti cally dif fe rent in two gro ups of pa ti ents. All pa ti ents we re cli ni cally euth yro id be fo re sur gery. Conc lu si on: LS tre at ment, ei t her alo ne or to get her with an tith yro id drugs, is a sa fe and ef fec ti ve cho i ce for the ra pid pre pa ra ti on of hyperth yro id pa ti ents for thyro i dec tomy, in de pen dent from the eti o logy of hyper th yro i dism.

Although the effects of hypothyroidism or hyperthyroidism on weight have clearly been demonstrated, data regarding the effects of relatively minor defects in thyroid function are limited. In the present study, the relationship between body mass index (BMI) and alterations in thyroid function within the normal range was investigated in obese patients. Three hundred fifty-seven euthyroid, obese patients (309 female and 48 male; mean age, 42 years) were included in the study. The patients were divided into 2 groups based on a BMI threshold value of 40 kg/m(2). Thyroid function, BMI, and the epidemiologic characteristics of the patients were retrospectively evaluated. No statistically significant difference was detected between the groups with respect to gender, place of birth, place of residence, smoking habits, and family history. Severely obese patients with a BMI >= 40 kg/m(2) were older and had a lower serum-free thyroxine level (fT4) than obese patients with a BMI < 40 kg/m(2) (P < 0.01). In patients with normal thyroid function, a negative correlation between fT4 and BMI existed. No statistically significant association was detected between BMI and epidemiologic characteristics in euthyroid, obese patients.

The corrosion inhibition characteristics of quaternized 1,(4)-tetrakis[(2-mercapto)pyridine]phthalocyanine (I) and 2,3-octakis[(2-mercapto)pyridine] phthalocyanine (II) on aluminum in 0.1 M HCl solution has been studied by means of potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques. The maximum inhibition efficiency was obtained for compound I with two-electrochemical techniques applied. Langmuir isotherm fits well the experimental data. The inhibition efficiency increases with increase in the phthalocyanine concentration, but decreases with an increase in temperature. The phthalocyanines act predominately as cathodic inhibitor.

The aim of the present work is to investigate the kinetic properties of Co-B nanoparticles which are deposited on graphene sheets by simultaneous chemical reduction of Co+2 and graphite oxides using NaBH4 as the reducing agent. The reduced Co-B/graphene nanocomposites were characterized by X-ray diffraction, and the effects of the concentration of NaBH4, NaOH, and hydrolytic temperature were discussed in detail. The results show that the concentration of NaBH4 and NaOH indeed exerted a significant impact on the hydrogen generation rate of Co-B/graphene catalysts. Reaction rate of hydrolysis first rises up and then decreases subsequently with the rising of NaOH and NaBH4 concentration. The results show that the Co-B/graphene catalyst has the high catalytic activity with activation energy of 52.45 kJ.mol(-1), and showed high resistance against deterioration and stability as a function of time. The present method is promising for the synthesis of effective supported catalysts for hydrolysis of NaBH4. (C) 2015 AIP Publishing LLC.

Recurrent episodes of hypoglycemia in patients with diabetes are often associated with the ongoing treatment regimen. However, despite changes in treatment modalities, assessment of the causes of hypoglycemia in nondiabetic patients in the presence of severe and recurrent hypoglycemia is very important. The treatment that had been provided for 6 years in a 67-year-old female patient with type 2 diabetes mellitus was discontinued due to hypoglycemic episodes that presented for the previous 2 years. The patient experienced persistent hypoglycemia after cessation of the treatment and was hospitalized for further examination. Spontaneous hypoglycemia with a final diagnosis of insulinoma was established following histopathologic evaluation and was relieved postoperation. Insulinoma is rarely encountered as a cause of hypoglycemia in patients with type 2 diabetes. Insulin-secreting tumors should be considered where hypoglycemic episodes occur despite discontinuation of insulin and other antidiabetic treatment with endogenous hyperinsulinemia being noncompliant with the blood glycemic levels.

Purpose: The purpose of the present study was to evaluate the effects of different loading doses of clopidogrel on ST segment resolution on ECG, changes in cardiac enzyme levels and serum levels of high-sensitivity C-reactive protein (Hs-CRP) in patients with ST elevated myocardial infarction (STEMI) treated with fibrinolytic therapy. Methods: Patients admitted to our cardiology clinic with a diagnosis of STEMI and treated with fibrinolytic therapy were included: Group 1 (n=58) received a 300 mg loading dose of clopidogrel, Group 2 (n=55) a 450 mg loading dose and Group 3 (n=59) a 600 mg loading dose. A 75 mg/d maintanence dose of clopidogrel was given in all groups. Results: All demographic characteristics and baseline laboratory parameters were statistically similar among three groups (p > 0.05). When ST resolution periods were compared, most patients in Group 3 had ST resolution at 30 minutes; Group 2 at 60 minutes and Group 1 at 90 minutes (p < 0.05). Peak levels of creatine kinase (CK) and CK-MB were as follows: Group 3, 8th hour, Group 1 and 2, 12th hour. Peak levels of those enzymes were significantly lower in Group 3 than in Group 1 and 2 ( < 0.05). Although basal hs-CRP levels of all groups were similar, the increase in hs-CRP levels at 48 hours was lower with higher clopidogrel loading doses (p < 0.05). Conclusion: In this study comparing three different clopidogrel loading doses, the higher doses provided earlier ECG resolution, earlier and lower peak CK and CK-MB levels and lower levels of hs-CRP.

Bu tez çalışmasında Değişken Ardışık Hücre Yönlü Kapalı Formülasyon Metodu, Yaklaşık Çarpanlara Ayırma yaklaşımıyla birleştirilmiştir. Bu uygulama, Değişken Ardışık Hücre Yönlü Kapalı Formülasyon Metodu'nun matematiksel olarak daha iyi tanımlanmış bir versiyonunu ortaya koymayı ve kısmi diferansiyel denklemlerin çözümü için kullanılan bu metodun başarısını arttırmayı hedeflemektedir.Burada sunulan iterasyon şeması daimi difüzyon denklemi, Laplace denklemi ve konveksiyon-difüzyon denklemi kullanılarak test edilmiştir. Şemanın doğruluk, yakınsama ve kararlılık karakterleri yapısal ve yapısal olmayan dörtgen sayısal ağlar kullanılarak uygun iterasyon şemalarıyla karşılaştırılmıştır. Ayrıca önerilen şemanın üçgen ve hibrit çokgen sayısal ağlara uygulanabilir olduğu gösterilmiştir.Şema kullanılarak transonik tam potansiyel bir çözücü geliştirilmiştir. 2-B silindir etrafında kritik altı ve kritik üstü akış çözülmüştür. Problem olarak eksenel simetrik silindir probleminin seçilmiş olmasının sebebi küt hücum kenarlı cisimler etrafındaki akış çözümlerinin ince cisimler etrafındaki akış çözümlerinden daha zor olmasıdır.Aynı zamanda metodun doğası gereği paylaşımlı bellek kullanımında paralelleştirmeye uygun olduğu gösterilmiştir. Burada uygulanan paralelleştirme kısmen çizgi, kısmen nokta paralelliğidir. Uygulamanın performansı basit bir 3-B daimi difüzyon problemi üzerinde Kartezyen elemanlar kullanılarak ve 2-B daimi difüzyon denklemi üzerinde yapısal ve yapısal olmayan dört kenarlı elemanlar kullanılarak sunulmaya çalışılmıştır. In this thesis study, a fast implicit iteration scheme called Alternating Cell Directions Implicit method is combined with Approximate Factorization scheme. This application aims to offer a mathematically well defined version of the Alternating Cell Directions Implicit Method and increase the accuracy of the iteration scheme that is being used for the numerical solutions of the partial differential equations.The iteration scheme presented here is tested using unsteady diffusion equation, Laplace equation and advection-diffusion equation. The accuracy, convergence character and the stability character of the scheme compared with suitable iteration schemes for structured and unstructured quadrilateral grids. Besides, it is shown that the proposed scheme is applicable to triangular and hybrid polygonal grids.A transonic full potential solver is generated using the current scheme. The flow around a 2-D cylinder is solved for subcritical and supercritical cases. Axi-symmetric flow around cylinder is selected as a benchmark problem since the potential flow around bodies with a blunt leading edge is a more challenging problem than slender bodies.Besides, it is shown that, the method is naturally appropriate for parallelization using shared memory approach without using domain decomposition applications. The parallelization that is performed here is partially line, partially point parallelization. T he performance of the application is presented for a 3-D unsteady diffusion problem using Cartesian cells and 2-D unsteady diffusion problem using both structured and unstructured quadrilateral cells. 114

The objective of this study was to investigate the effect of G870A gene polymorphism of CCND1 on the formation and behavioral features of prolactinomas. One hundred and thirteen patients with prolactinoma and 108 age and gender matched control were included in the study. The patients were divided into two groups as noninvasive and invasive tumors. CCND1 G870A gene polymorphism was compared in patients/control and invasive/noninvasive groups. A and G allele frequencies were found as 41.7% and 58.3% in the controls, and 61.1% and 38.9% in the patients (p

Aim Sitagliptin is not associated with weight gain and has neutral effects on body weight. It is unclear whether sitagliptin treatment alters serum ghrelin levels in people with type 2 diabetes. Methods Forty-four subjects with type 2 diabetes were randomly assigned to receive sitagliptin or medical nutrition therapy (MNT) for 12 weeks. Changes in anthropometric variables, glycemic control, insulin resistance, lipid parameters, and total ghrelin levels were evaluated at baseline and following 12 weeks of treatment. Results Significant decreases in body weight and body mass index were observed over the entire study period in both treatment groups. Glycosylated hemoglobin and postprandial plasma glucose levels were statistically significant decreased in the groups receiving sitagliptin compared with baseline values ( p = 0.021 and p = 0.021, respectively), while they were unchanged in the groups receiving MNT. There was a significant decrease in total ghrelin in the groups receiving sitagliptin ( p = 0.04) compared with baseline values but not in the groups receiving MNT ( p = 0.46) at the end of the 12 weeks. Conclusions In this study of patients with type 2 diabetes, treatment with sitagliptin was associated with a significant decrease in serum ghrelin levels. These results suggest that the neutral effect of sitagliptin on weight might be associated with the suppression of fasting serum ghrelin levels.

Mobile agents (MAs) are a promising technology which directly address physical limitations of mobile devices such as limited battery life, intermittent and low-bandwidth connections, with their capability of providing disconnected operation. This chapter addresses the problem of digital contract signing with MAs, which is an important part of any mobile commerce activity and one special challenging case of computing with secrets remotely in public. The authors use a multi-agent model together with simple secret splitting schemes for signing with shares of a secret key carried by MAs, cooperating to accomplish a trading task. In addition to known key splitting techniques of RSA, authors introduce similar techniques for El Gamal and DSS public key cryptosystems. The objective is to achieve a simple and ubiquitous solution by using the well-known public-key cryptosystem implementations, which conform to the established standards.

A series of thin Pt films were deposited by dc magnetron sputtering directly on a commercial hydrophobic carbon paper substrate having a thin microporous Vulcan-XC72 layer or upon a thin Ti sublayer sputtered on the top of the microporous carbon film. The electrocatalytic properties of the sputtered Pt films toward the oxygen reduction reaction were investigated in 0.5 M H2SO4 solution and in a hydrogen PEM fuel cell. The catalyst with ultralow Pt loading of 22 mu g cm(-2) deposited on a 33 angstrom thick Ti sublayer is robust, mechanically stable, possesses highly developed surface area and improved catalytic efficiency. Its performance as a MEA cathode in a single hydrogen PEM fuel cell (577 mA cm(-2) at 0.4 V cell voltages and a maximum power of 0.954W) proved to be much superior compared to that of MEA with the same cathode Pt loading but without Ti sublayer (173 mA cm(-2) at 0.4 V, 0.231W, respectively). (C) 2010 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.

Purpose: Diastolic heart failure is characterized by the presence of heart failure symptoms despite preserved systolic function. Cytokines released during allergic reactions may impair diastolic heart function, either through their direct toxic effects or by inducing coronary artery spasm. The purpose of this study was to examine the effects of acute allergic reactions on diastolic heart function. Methods: Fifty patients, randomly selected from those who were admitted to the emergency room between May 2010 and December 2010 with the complaints of rash and itching, and who were subsequently diagnosed with allergic reactions based on the clinical and laboratory findings, were included in the study as the allergy group. Thirty healthy volunteers, in whom the diagnosis of allergy was ruled out based on the clinical and laboratory data, were use as the control group. Diastolic heart functions were evaluated in patients presenting with allergic reaction as well as in control subjects. Results: There was no significant difference between the two groups in terms of basal systolic functions, diameters of the cavities and wall thicknesses, and biochemical parameters. Color M mode flow progression velocities, E ratios, E/A ratios and mitral lateral annulus tissue Doppler velocities measured by echocardiography at Day 0 and Day 5 were significantly altered in the allergy group (p < 0.05). Conclusion: Impairment in diastolic functions was observed following acute allergic reactions. Acute allergic reactions could be a cause of mortality and morbidity if they lead to the development of diastolic heart failure.

Corrigendum to “Effect of cyclin D1 (CCND1) gene polymorphism on tumor formation and behavior in patients with prolactinoma” [Gene 509 (2012) 158–163] Soner Cander ⁎, Erdinc Erturk , Mutlu Karkucak , Ozen Oz Gul , Orhan Gorukmez , Tahsin Yakut , Oguz Kaan Unal, Canan Ersoy , Ercan Tuncel , Sazi Imamoglu a a Uludag University, Medical School, Department of Endocrinology and Metabolism, Bursa, Turkey b Uludag University, Medical School, Department of Medical Genetic, Bursa, Turkey c Bursa Sevket Yilmaz Education and Research Hospital, Department of Endocrinology and Metabolism, Bursa, Turkey

Due to its empirical success on few shot classification and reinforcement learning, meta-learning recently received a lot of interest. Meta-learning leverages data from previous tasks to quickly learn a new task, despite limited data. In particular, model agnostic methods look for initialisation points from which gradient descent quickly adapts to any new task. Although it has been empirically suggested that such methods learn a good shared representation during training, there is no strong theoretical evidence of such behavior. More importantly, it is unclear whether these methods truly are model agnostic, i.e., whether they still learn a shared structure despite architecture misspecifications. To fill this gap, this work shows in the limit of an infinite number of tasks that first order ANIL with a linear two-layer network architecture successfully learns a linear shared representation. Moreover, this result holds despite misspecifications: having a large width with respect to the hidden dimension of the shared representation does not harm the algorithm performance. The learnt parameters then allow to get a small test loss after a single gradient step on any new task. Overall this illustrates how well model agnostic methods can adapt to any (unknown) model structure.

Data augmentation is a widely adopted technique for avoiding overfitting when training deep neural networks. However, this approach requires domain-specific knowledge and is often limited to a fixed set of hard-coded transformations. Recently, several works proposed to use generative models for generating semantically meaningful perturbations to train a classifier. However, because accurate encoding and decoding are critical, these methods, which use architectures that approximate the latent-variable inference, remained limited to pilot studies on small datasets. Exploiting the exactly reversible encoder-decoder structure of normalizing flows, we perform on-manifold perturbations in the latent space to define fully unsupervised data augmentations. We demonstrate that such perturbations match the performance of advanced data augmentation techniques -- reaching 96.6% test accuracy for CIFAR-10 using ResNet-18 and outperform existing methods, particularly in low data regimes -- yielding 10--25% relative improvement of test accuracy from classical training. We find that our latent adversarial perturbations adaptive to the classifier throughout its training are most effective, yielding the first test accuracy improvement results on real-world datasets -- CIFAR-10/100 -- via latent-space perturbations., In Proceedings of the IEEE International Conference on Computer Vision

Objective: To evaluate the ovarian reserve function in female patients with metabolic syndrome (MetS). Methods: This study evaluated 136 subjects, 67 with MetS and 69 controls. Subjects were divided into three age groups. Group I included 49 subjects aged 20–29 years, 22 with MetS and 27 controls; group II included 45 subjects aged 30–39 years, 22 with MetS and 23 controls; and group III included 42 subjects aged 40–49 years, 23 with MetS and 19 controls. Demographic characteristics, anthropometrics, blood biochemistry, and gonadotrophic hormones were compared as total ovarian volume and antral follicle count on ovarian transvaginal ultrasonography. Results: Serum levels of FSH, LH, E2 and progesterone were similar in the MetS and control groups, while testosterone levels were significantly higher in MetS patients than controls, both in the overall population (p = 0.024) and in those aged 20–29 years (p = 0.018). Total ovarian volume was significantly lower in MetS patients than controls, in both the overall population (p = 0.003) and those aged 20–29 years (p = 0.018), while antral follicle counts were similar. Ovarian volume correlated positively with antral follicle count (AFC) (r = 0.37; p < 0.001) and negatively with age (r = 0.34; p < 0.001) and FSH concentration (r = 0.21; p = 0.013). AFC was negatively correlated with age (r = 0.36; p < 0.001). Conclusion: Ovarian reserve function is significantly lower in MetS patients than in healthy control subjects, particularly in women aged 20–29 years.