Increased cerebral blood flow in the right anterior cingulate cortex and fronto-orbital cortex during go/no-go task in children with ADHD

Objective Arterial spin labeling (ASL) is a relatively new imaging modality in the field of the cognitive neuroscience. In the present study, we aimed to compare the dynamic regional cerebral blood flow alterations of children with ADHD and healthy controls during a neurocognitive task by using event-related ASL scanning. Methods The study comprised of 17 healthy controls and 20 children with ADHD. The study subjects were scanned on 3 Tesla MRI scanner to obtain ASL imaging data. Subjects performed go/no-go task during the ASL image acquisition. The image analyses were performed by FEAT (fMRI Expert Analysis Tool) Version 6. Results The mean age was 10.88 +/- 1.45 and 11 +/- 1.91 for the control and ADHD group, respectively (p = .112). The go/no-go task was utilized during the ASL scanning. The right anterior cingulate cortex (BA32) extending into the frontopolar and orbitofrontal cortices (BA10 and 11) displayed greater activation in ADHD children relative to the control counterparts (p < .001). With a lenient significance threshold, greater activation was revealed in the right-sided frontoparietal regions during the go session, and in the left precuneus during the no-go session. Conclusion These results indicate that children with ADHD needed to over-activate frontopolar cortex, anterior cingulate as well as the dorsal and ventral attention networks to compensate for the attention demanded in a given cognitive task

Psychiatric Comorbidity in the Subtypes of ADHD in Children and Adolescents with ADHD According to DSM-IV

Introduction: The prevalence rate of psychiatric comorbidity in children and adolescents with Attention Deficit Hyperactivity Disorder (ADHD) was 60-80%. The objective of this study was to examine comorbid disorders associated with ADHD and the subtypes of ADHD in children and adolescents with the diagnosis of ADHD. Method: The study included 326 children and adolescents aged between 8-15 years who were diagnosed with ADHD for the first time as a result of an interview by psychiatry, in a child adolescent psychiatry clinic in Izmir. Sociodemographic form, Turgay DSM-IV Disruptive Behavior Disorders Rating Scale and Kiddie Schedule for Affective Disorders and Schizophrenia for School-Age Children Present and Lifetime version were used to assess psychiatric comorbidity. Results: The comorbidities accompanied ADHD were disruptive behavior disorder (28.8%), depressive disorder (13.2%), obsessive-compulsive disorder (9.5%) and anxiety disorder (6.1%), in respectively. When the subtypes of ADHD were assessed according to psychiatric comorbidity, oppositional defiant disorder and conduct disorder were frequently seen with ADHD combined type, whereas anxiety disorder was seen more frequent in children diagnosed with ADHD inattentive type. Discussion: Especially the presents of comorbidities in cases with ADHD Combined type increases the severity of disease, causes to retard in responses to treatment and exacerbates prognosis. Therefore, it is very important to determine which psychiatric diagnosis accompany with ADHD

Patterns of multiple primaries in fortyfour cancer patients: a single-center clinical experience

Introduction. Multiple primaries are defined as the existence of more than one synchronous or metachronous cancer type in the same individual. Due to a longer follow-up time after a primary cancer diagnosis, the likelihood of detection of a second primary is also increased. We report on patterns of multiple primaries in a cohort of cancer patients from a single institution.  Material and methods. We identified 44 patients with multiple primaries that were diagnosed, treated, and followed up between March 2011 and January 2022 from our prospectively maintained database at the Hatay Education and Research Hospital Cancer Unit.  Results. The median follow-up time was 60 months (range; 3–103). The median time between the diagnosis of the first primary and the second primary was 29 months (range; 0–94). The median OS was 76 months (95% Cl 26.6–125.4) from the first diagnosis and 27 months (95% Cl 0.65–53.4) from the diagnosis of the second primary for the entire cohort. The first diagnosed tumor was localized in the gastrointestinal system in 43.2% of patients and 65.9% of all tumors were adenocarcinoma. The first diagnosed cancer was at an early stage (Stages I and II) in 63.6% of patients. At the staging evaluation of the second primary, 54.5% of patients were found to be in the early stage (Stages I and II) and 45.5% were found to be in the late stage (Stages III and IV).  Conclusions. Our study is important as this is the largest cohort study about practical implications of managing multiple primaries. The risk of second and further primaries should be kept in mind in the active follow-up Introduction and surveillance of cancer patients

Investıgatıon Of The Fluıd Flow And Heat Transfer In Narrow Radıator Channels

Bu çalışmada, sıcaklık ve akış alan denklemleri yeni bir nümerik çözüm yöntemi kullanılarak, ikizkenar üçgen, sinüzoit ve parabolik kesitli radyatör hava kanallarının akış ve ısı transferi karakteristikleri belirlenmiştir. Hava kanallarındaki akış ve ısı transferi, hem tam gelişmiş akış hem de gelişmekte olan akış için modellenmiştir. Her iki durumda, akışın sıkışmaz ve laminer olduğu kabul edilmiştir. Giriş bölgesinde hız ve sıcaklık sınır tabaklarının eş zamanlı olarak geliştiği kabul edilmektedir. Kanalların giriş bölgesindeki akış alanları 3 boyutlu momentum denklemleri ile süreklilik ve momentum denklemlerinin bileşiminden elde edilen Poisson tipi bir basınç alan denklemi ile modellenmiştir. Sinüzoidal, parabolik ve ikizkenar üçgen şeklindeki kanal kesitleri ısı transferi ve akış alan denklemleri için düzensiz çözüm bölgeleri olduğundan bir takım zorluklarla karşılaşılmaktadır. Bu zorlukları yok etmek için kanalların kesit alanları uygun transformasyonlar kullanılarak kare şeklindeki çözüm bölgelerine dönüştürülmüştür. Yönetici denklemlerin içerdiği sıcaklık ve hız bileşenleri de uygun transformasyonlar kullanılarak boyutsuz büyüklüklere dönüştürülmüştür. Yönetici denklemler sonlu fark şekline dönüştürüldükten sonra Newton-Raphson yöntemi kullanılarak sayısal yöntemle çözülmüştür. Tam gelişmiş akış bölgesindeki ısı transferi, sabit ısı akısı (H1) ve sabit duvar sıcaklığı (T) olmak üzere iki farklı ısıl duvar şartı ile incelenmiştir. Kanalların farklı boy/en oranları için Nusselt ve Poiseuille sayıları belirlenmiştir. Sonuçlar literatür verileri ile kıyaslanmış ve uyumlu olduğu görülmüştür. Maksimum sapmanın % 3'ten az olduğu görülmüştür. Giriş bölgesindeki ısı transferinin analizinde sabit duvar sıcaklığı şartı uygulanmıştır. Reynolds sayısının 250, 500, 750, 1000 ve 12000 değerlerine karşılık gelen eksenel Nusselt sayısı dağılımları belirlenmiştir. Sabit duvar sıcaklığına haiz ve boy/en oranı 1,0 olan bir ikizkenar üçgenin giriş bölgesindeki eksenel Nusselt sayısı dağılımı ANSYS Fluent yazılımı ile de hesaplanmış ve bu tezde geliştirilen metotdan elde edilen Nusselt sayısı dağılımı ile karşılaştırılmıştır. Sonuçların birbiri ile çok uyumlu olduğu görülmüştür.In this study, the flow and heat transfer characteristics of the radiator air ducts with isosceles triangular, sinusoidal and parabolic cross sections are investigated by using a new numerical solution method for temperature and flow field equations. The flow and heat transfer in air ducts are modeled for both the fully developed and developing flows. For both situations, the flow was assumed to be incompressible and laminar. In the entrance region, the velocity and temperature boundary layers are assumed to be simultaneously developing. The flow field in the entrance regions of the ducts are modeled with three dimensional momentum equations and a Poisson type pressure field equation obtained from the combination of the continuity and momentum equations. Due to that the sinusoidal, parabolic and isosceles triangles are non-regular solution domains of the governing equations of the flow and heat transfer fields, some difficulties are confronted. To eliminate these difficulties, the cross-sectional areas of ducts were transformed into square-shaped solution domains by using appropriate transformations. Velocity components and fluid temperature involved by governing equations are converted to dimensionless quantities by means of using appropriate transformations as well. Governing equations are solved numerically via Newton-Raphson method after being converted to the finite difference form. The heat transfer in the fully developed flow zone are investigated for two different thermal wall conditions as constant heat flux (H1) and constant wall temperature (T). Nusselt and Poiseuille numbers are calculated for various height /width ratios of the ducts. The results are compared with the literature data and found to be consistent. The maximum deviation is determined to be less than 3 %. In the analysis of entrance flow heat transfer, the condition of constant wall temperature is implemented. Axial distributions of Nusselt numbers are determined corresponding to 250, 500, 750, 1000 and 1200 values of Reynolds numbers. The axial distribution of the Nusselt number of a triangular duct with constant wall temperature is calculated for 1,0 of height/width ratio via ANSYS Fluent software and compared with the results of the developed method in the thesis. Result were found to be very compatible with each other

Fonksiyonel Derecelendirilmiş Konik Kesitli Mikro Kirişlerin Serbest Titreşim Analizi

In this thesis a theoretical investigation in free vibration of a functionally graded tapered (FG) micro beam is presented. It is assumed that material properties vary along the beam thickness according to power law distributions. The governing equation is reduced to an ordinary differential equation in spatial coordinate for cross-section geometries with exponentially varying width. The vibration behaviors of micro-beams made of functionally graded materials are analytically investigated on the basis of the modified couple stress theory in the elastic range. The governing equations of motion and boundary conditions are derived on the basis of Hamilton principle. Analytical solutions of the natural frequencies are obtained for exponential FG beams with hinged-hinged, clamped-clamped and clamped-free end supports. Solutions for the natural frequencies are obtained FGM distribution functions of properties and as a function of the ratio of the beam characteristic size to the internal material length scale parameter.Bu tezde değişken kesite alanlı fonksiyonel derecelendirilmiş (FD) bir mikro kirişin serbest titreşimi teorik olarak incelenmiştir. Malzeme özelliklerinin kirişin kalınlığı doğrultusunda kuvvet yasası dağılımına göre olduğu varsayılmıştır. Ana denklem, vektörel koordinat sisteminde genişliği üstel olarak değişen kesit alan geometrisi için adi diferansiyel bir denkleme indirgenmiştir. Fonksiyonel derecelendirilmiş malzemeden yapılan mikro kirişlerin titreşim davranışları modifiye gerilme çifti teorisi baz alınarak elastik değişim aralığında analitik olarak incelenmiştir. Ana hareket denklemleri ve sınır koşulları Hamilton prensibi ile türetilmiştir. Doğal frekansların analitik sonuçları, her iki ucu basit mesnetli, her iki ucu ankastre ve bir ucu ankastre diğer ucu serbest üstel FD kirişler için elde edilmiştir. Doğal frekanslar için çözümler kirişin karakteristik büyüklüğünün malzeme iç uzunluk parametresine oranı olarak ve FDM dağılım fonksiyonu özelliklerine göre elde edilmiştir

Methylphenidate significantly improves neurocognitive impairments in children with ADHD

This study aimed to investigate the effects of methylphenidate (MPH) on scores on a neurocognitive test battery for individuals with various presentations of attention deficit/hyperactivity disorder (ADHD) and the effect of comorbidities on executive function. This study included 861 children and adolescents aged 7-17 years who were diagnosed with ADHD according to DSM-V criteria. The CNS Vital Signs Battery was utilized to compare the neuropsychological characteristics and MPH treatment responses of patients with predominantly inattentive (ADHD-I) and combined (ADHD-C) presentations of ADHD. Before MPH administration, a statistically significant difference was observed between groups only for complex attention. In addition, the overall prevalence rate of psychiatric comorbidities was 45.5%, and no statistically significant differences were found in the ADHD-I group pre-versus post-MPH administration. Prior to the administration of MPH, statistically significant differences were observed within the ADHD-C group between those with or without comorbidities. However, after MPH administration, these differences between the groups disappeared. The effects of MPH on improving scores on neuropsychological subtests were similar between the groups with different presentations of ADHD. Additionally, MPH treatment was effective despite the presence of comorbidities

CONTROL OF COMBUSTION PHASE WITH DIRECT INJECTION TIMING FOR DIFFERENT INLET TEMPERATURES IN AN RCCI ENGINE

The increasingly stringent emission regulations for the road transport sector require the implementation of new emission reduction techniques for internal combustion engines. In order to reduce exhaust emissions, some precautions must be taken after or during combustion. Low temperature combustion cycles are a popular research subject because they provide both low emission levels and high energy conversion rate. Reactive controlled compression ignition (RCCI) combustion mode is advantageous in that the combustion phase is more controllable and offers a wider operating range than other low temperature combustion modes. However, in RCCI mode, the start of the direct injection must be controlled instantaneously in order to ensure the highest efficiency in every operating condition. In this study, a direct injection gasoline engine with a compression ratio of 9,2 was operated in RCCI mode, and the start of the direct injection was controlled according to the instantaneous change of the combustion phase (KA50) and the injection advance map and operation maps were obtained for different inlet air temperatures. The widest operating range was achieved at an inlet temperature of 80 degrees C. The minimum specific fuel consumption was measured as 232,3 g/kWh. Although the compression ratio of the engine used is very low, the specific fuel consumption values are quite low, which is an indication of successful combustion phase contro