HfO2, Al2O3, and ZnO based Metal-Insulator-Metal photovoltaic structures for solar cell applications

Currently, the solar cell market is dominated by silicon-based solar cell since the bandgap of the silicon is an appropriate match to solar spectrum and silicon is most abundant material on the earth. However, the efficiency of the silicon-based solar cells is limited hence the research and development are concentrated on alternative methods. The Metal-Insulator-Metal(MIM) diode consists of an insulator layer sandwiched between two metals. The current generation mechanism is based on the photovoltaic effect that enables to form Metal-Insulator-Metal solar cells. The technological development allows leading investigations about developing highly efficient MIM diode promising broad applications. MIM diodes have several advantages such as low cost, potentially having high conversion efficiency, integrated circuit (IC) compatibility. Therefore, the feasibility of MIM diodes for solar cell application is explored. In the MIM diode, insulator layers are an integral part of the devices, preponderantly determining the performance parameters. MIM diodes with different material selections based on three insulators (HfO2, Al2O3, and ZnO) and three metals (Au, Cr, and Ni) are evaluated to compare performance parameters, with conversion efficiency being prioritized. Based on the responsivities of the devices, the HfO2-based MIM diode gives the highest efficiency under visible light due to the fact that hot electron and leading electrons tunnel through thin energy barrier more asymmetric than the other MIM diodes enabling more number of hot electrons tunneling through. Hence insulating layer is a critical parameter in terms of tunneling probability of hot electrons and optimizing conversion efficiency. At the end of this study, Metal Insulator Metal structure is combined with a converter module that charges a battery that demonstrates the feasibility of MIM solar cel

Genotoxicity of anti-tumor necrosis factor therapy in patients with juvenile idiopathic arthritis

Objective. To assess the possible effects of both inflammation and the anti-tumor necrosis factor agents (anti-TNF) on DNA damage with a specific assay, and their effects on the repair capacity of DNA. Methods. From a group of 20 children with juvenile idiopathic arthritis (JIA), 16 patients who completed the study and 16 control subjects were evaluated. DNA damage and repair capacity were analyzed by the comet assay at the level of peripheral lymphocytes before anti-TNF (etanercept) injections and on the 15th, 90th, and 180th days after the first injection. Results. The amount of damage as detected by the aforementioned assay was higher in patients with JIA compared with controls. On the 15th day after the initial anti-TNF injection, there was a decrease in the mean DNA tail length of JIA patients, however on the 90th day an increase was observed; thereafter, an upward trend was observed until the end of the study. JIA patients had a DNA repair capacity that was significantly less than that of controls. Conclusion. The results of the comet technique suggests that JIA patients already have increased basal DNA damage before anti-TNF therapy; they are more sensitive to the DNA damage produced by H 2O 2, and have a less efficient DNA repair system in comparison with control cells. After an initial improvement at 2 weeks, parameters of genotoxicity worsened, and DNA repair was further impaired 6 months after the addition of an anti-TNF agent to treatment. © 2010, American College of Rheumatology

Highly efficient MIM diodes for NIR and SWIR applications

Metal-insulator-metal (MIM) diodes are highly considered in high frequency applications in form of rectennas for energy harvesting applications due to their fast speed, small size, and ease of fabrication and IC compatibility. In these diodes, insulators are integral part of the device, determining performance parameters. In this study, we have evaluated HfO2 and Al2O3 based MIM diode structures to compare and determine performance parameters, with conversion efficiency being prioritized. The fabrication processes in physical vapor deposition (PVD) systems for the MIM diodes resulted in the devices having high non-linearity and responsivity. Also, to achieve uniform and very thin insulator layer atomic layer deposition (ALD) was used. We implemented the same MIM structure in 10x10 array form, with active area of 200×325 nm2. The efficiency values of same arrays tested with 1200 and 1600 nm wavelength LEDs for 200×325 nm2 diode active area without applying bias. The conversion efficiency value of the HfO2 based structures calculated as 5% for 1200 nm wavelength. These measured values of conversion efficiency are reported for the first time in the literature for MIM diodes in SWIR operation

Array size and area impact on nanorectenna performance properties

The metal-insulator-metal (MIM) diodes have high speed and compatibility with integrated circuits (IC's) making MIM diodes very attractive to detect and harvest energy for infrared (IR) regime of the electromagnetic spectrum. Due to the fact that small size of the MIM diodes, it is possible to obtain large volume of devices in same unit area. Hence, MIM diodes offer a feasible solution for nanorectennas (nano rectifiying antenna) in IR regime. The aim of this study is to design and develop MIM diodes as array format coupled with antennas for energy harvesting and IR detection. Moreover, varying number of elements which are 4x4, and 40x30 has been fabricated in parallel having 0.040, 0.065 and 0.080 μm2 diode area. For this work we have studied given type of material; Ti-HfO2-Ni, is used for fabricating MIM diodes as a part of rectenna. The effect of the diode array size is investigated. Furthermore, the effect of the array size is also investigated for larger arrays by applying given type of material set; Cr-HfO2-Ni. The fabrication processes in physical vapor deposition (PVD) systems for the MIM diodes resulted in the devices having high non-linearity and responsivity. Also, to achieve uniform and very thin insulator layer atomic layer deposition (ALD) was used. The nonlinearity 1.5 mA/V2 and responsivity 3 A/W are achieved for Ti-HfO2-Ni MIM diodes under low applied bias of 400 mV. The responsivity and nonlinearity of Cr-HfO2-Ni are found to be 5 A/W and 65 μA/V2, respectively. The current level of Cr-HfO2-Ni and Ti-HfO2-Ni is around μA range therefore corresponding resistance values are in 1-10 kΩ range. The comparison of single and 4x4 elements revealed that 4x4 elements have higher current level hence lower resistance value is obtained for 4x4 elements. The array size is 40x30 elements for Cr-HfO2-Ni type of MIM diodes with 40, 65 nm2 diode areas. By increasing the diode area, the current level increases for same size of array. The current level is increased from10 μA to100 μA with increasing the diode area. Therefore resistance decreased in the range of 10 kΩ and nonlinearity is increased from 58 μA/V2 to 65 μA/V2

A low-power CMOS readout IC design for bolometer applications

A prototype of a readout IC (ROIC) designed for use in high temperature coefficient of resistance (TCR) SiGe microbolometers is presented. The prototype ROIC architecture implemented is based on a bridge with active and blind bolometer pixels with a capacitive transimpedance amplifier (CTIA) input stage and column parallel integration with serial readout. The ROIC is designed for use in high (≥ 4 %/K) TCR and high detector resistance Si/SiGe microbolometers with 17x17 μm2 pixel sizes in development. The prototype has been designed and fabricated in 0.25- μm SiGe:C BiCMOS process

Štetni učinci pušenja tijekom trudnoće na DNA i razine reaktivnih oblika kisika (ROS) u krvi majke i novorođenčeta

Some of the genotoxic/carcinogenic substances or metabolites in cigarette smoke are capable of passing through the placenta and harming a newborn’s health. Smoking is also known as a factor in the formation of oxidative damage and the main mechanism involved in the carcinogenic process. Predetermining this genotoxic risk can be successfully achieved by measuring certain parameters of oxidative stress. The comet assay is considered an important biomarker for the evaluation of genotoxic substances and is effective for detecting DNA damage caused by smoking. This study examined third trimester bloods and the cord blood of 28 actively smoking and 22 non-smoking mothers in terms of DNA damage and oxidative stress parameters. Cu/Zn superoxide dismutase (CuZn-SOD), malondialdehyde (MDA), catalase (CAT), plasma nitrite/nitrates (NO2•/NO3•), selenium-dependent glutathione peroxidase (Se-GPx), Cu, and Zn levels were measured as indicators of oxidative damage. There were no significant increases in DNA damage of the actively smoking pregnant group in comparison with the non-smoking pregnant group, either in the third trimester or cord blood. Oxidative stress parameters of smoker and non-smoker groups were statistically different for MDA (p<0.05), CuZn-SOD (p<0.01), Se-GPx (p<0.05) values while the difference was not significant for NO2•/NO3•, CAT, Zn, and Cu values. The same values were also investigated in cord blood, and only NO2•/NO3• (p<0.01), Se-GPx (p<0.01 and CAT (p<0.001) values were found statistically different. Smoking mothers may have been exposed to more oxidative stress than non-smoking mothers.Pojedine genotoksične/kancerogene supstancije ili metaboliti u cigaretnom dimu mogu proći kroz posteljicu i naštetiti zdravlju novorođenčeta. Pušenje je također poznato kao čimbenik pri nastanku oksidacijskog oštećenja DNA i u procesu kancerogeneze. Ovaj genotoksični rizik može se uspješno odrediti mjerenjem određenih parametara oksidacijskog stresa. Komet-test smatra se važnim biološkim biljegom pri evaluaciji genotoksičnih supstancija i iznimno učinkovitim sredstvom pronalaženja oštećenja DNA uzrokovanih pušenjem. Ova studija proučava krv trudnica u trećem tromjesečju trudnoće i fetalnu krv 28 majki aktivnih pušačica te 22-ju majki nepušačica vezano za oksidacijska oštećenja DNA i parametre oksidacijskog stresa. Razine Cu/Zn superoksidne dismutaze (CuZn-SOD), malondialdehida (MDA), katalaze (CAT), nitrita/nitrata u plazmi (NO2-/NO3-), selenijeve glutation peroksidaze (Se-GPx), Cu i Zn mjerene su kao pokazatelji oksidacijskog oštećenja. Nije bilo značajnih povećanja oštećenja DNA u skupini trudnica aktivnih pušačica u usporedbi sa skupinom trudnica nepušačica, ni u krvi iz trećeg tromjesečja ni u fetalnoj krvi. Parametri oksidacijskog stresa pušačke i nepušačke skupine bili su statistički različiti za vrijednosti MDA (p<0,05), CuZn-SOD (p<0,01), Se-GPx (P<0,05), dok razlika nije bila značajna za vrijednosti NO2-/NO3-, CAT, Zn i Cu. Iste su vrijednosti ispitane i u fetalnoj krvi, a jedino su vrijednosti NO2-/NO3- (p<0,01), Se-GPx (p<0,01) i CAT (p<0,001) bile statistički različite. Vjerojatno je da su majke pušačice bile izložene većem oksidacijskom stresu od majki nepušačica

Genetics of immunoglobulin-A vasculitis (Henoch-Schönlein purpura): An updated review

Immunoglobulin-A vasculitis (IgAV) is classically a childhood small-sized blood vessel vasculitis with predominant involvement of the skin. Gastrointestinal and joint manifestations are common in patients diagnosed with this condition. Nephritis, which is more severe in adults, constitutes the most feared complication of this vasculitis. The molecular bases underlying the origin of IgAV have not been completely elucidated. Nevertheless, several pieces of evidence support the claim that genes play a crucial role in the pathogenesis of this disease. The human leukocyte antigen (HLA) region is, until now, the main genetic factor associated with IgAV pathogenesis. Besides a strong association with HLA class II alleles, specifically HLA-DRB1 alleles, HLA class I alleles also seem to influence on the predisposition of this disease. Other gene polymorphisms located outside the HLA region, including those coding cytokines, chemokines, adhesion molecules as well as those related to T-cells, aberrant glycosylation of IgA1, nitric oxide production, neoangiogenesis, renin-angiotensin system and lipid, Pyrin and homocysteine metabolism, may be implicated not only in the predisposition to IgAV but also in its severity. An update of the current knowledge of the genetic component associated with the pathogenesis of IgAV is detailed in this review.Acknowledgements: RL-Mis supported by the Miguel Servet I programme of the Spanish Ministry of Economy and Competitiveness through the grant CP16/ 00033. FG is recipient of a Sara Borrell postdoctoral fellowship from the “Instituto Carlos III de Salud” at the Spanish Ministry of Health (Spain) (CD15/00095). SR-M is supported by funds from the RETICS Program (RIER) (RD16/0012/0009). FDC is supported by the Ramón y Cajal programme of the Spanish Ministry of Economy and Competitiveness through the grant RYC-2014-16458

AFğİN-ELBİSTAN TERMİK SANTRALİ ÇEVRESİNDE YAğAYAN BİREYLERDE TERMİK SANTRALDEN KAYNAKLANAN TOKSİK MADDELERE MARUZİYETE BAĞLI OLASI GENOTOKSİK RİSKLERİN COMET VE KROMOZOM ABERASYONU YÖNTEMLERİYLE SAPTANMASI

Afsin-Elbistan A Termik Santrali&#8217;dir kurulduğu 1984 yılından bu yana desülfirizasyon ünitesi olmadan çalısmaktadır. Ayrıca partikül tutucu filtrelerin veriminin azalmasının sağlık için tehlike olusturabilecek maddelerin daha fazla miktarda çevreye yayılmasına neden olduğu düsünülmektedir. Çalısmamızda bu tür çevresel risklerin erken dönemde belirlenmesini sağlayabilen biyogöstergelerden yararlanılmıstır. Çalısmamızda A Santrali çevresinde yasayan bireylerde; termik santralden kaynaklanan atıkların maruziyetine bağlı, olası genotoksik risklerin Comet ve kromozom aberasyonu(CA) yöntemleriyle saptanması, DNA onarım kapasitelerinin belirlenmesi ve PAH bilesiklerine maruziyetin göstergesi olarak kabul edilen 1-Hidroksipiren (1-OHP) bilesiğinin, idrardaki miktarlarının HPLC yöntemi ile ölçülmesi gerçeklestirilmistir. Çalısmamızda Comet testinde genotoksik hasarının göstergesi olarak seçilen % kuyruk yoğunluğu±ss ortalaması; maruz grupta (8,79±1,88) kontrol grubuna göre göre (7,12±1,88) yüksek bulunmustur. Bu durum A Santrali çevresinde yasayan bireylerin genotoksik hasar miktarının kontrol grubuna göre fazla olduğu sonucunu ortaya koymaktadır (p<0.001). Çoklu regresyon analizi ile bu değerlerin yas ve yasanan yer ile birlikte değistiğini göstermektedir. Maruz grup ve kontrol grubundaki bireylerin %CA ortalamaları karsılastırıldığında; maruz grubun sonuçları (0,71±0,94) kontrol grubuna göre (0,49±0,71) yüksek olduğu görülmekle birlikte bu fark istatistiksel olarak anlamlı değildir. DNA onarım kapasiteleri değerlendirildiğinde maruz gruptaki bireylerin 20. ve 60. dakika için hesaplanan % onarım kapasitesi ortalamalarının (%34,15 ve 56,75) kontrol grubuna göre(%41,59 ve 64,19) düsük olduğu görülmüstür (p<0,05). Tek değiskenli modelde 1-OHP değerleri ve yasanan yer onarım kapasitesi üzerine etkiliyken, çoklu regresyon analizi ile yasanan yer ve 1- OHP dahil olmak üzere belirlenen risk faktörleri arasında istatistiksel anlamlılık bulunmamıstır. Maruz grubun H2O2&#8217; e olan duyarlılığı (13,46±4,36), kontrol grubuna (12,48±4,26) göre yüksek olmakla birlikte bu fark istatistiksel açıdan anlamlı değildir(p>0.05). Çalısmamızda 1-OHP ortalamaları maruz grupta (0,42±0,13) kontrol grubuna (0,25±0,07) göre yüksek bulunmustur. (p<0,001).Afsin-Elbistan A Thermal Power Plant (TPP) has been established and on duty without a desulphurization unite since 1984. Also the reduced capacity of particulate filter of the power plant introduce more potential risk for human health as more compounds released to the environment. In our study, biomarkers that can predict the environmental risks in early period have been used. Our study, our exposed group was consisted of individuals who were living near Afsin-Elbistan TPP. Possible genotoxic risks caused by TPP emissions exposure were evaluated by comet and Chromosomal Aberration (CA) tests. DNA repair capacities of the exposed population were also analyzed by comet test. 1-OHP which is thought to be biomarker of exposure to PAH compounds were determined by HPLC method in urine. Tail intensity levels which were selected as a marker of the genotoxic damage were found significantly higher (p<0,001) in exposed individuals then control group, respectively (8,79±1,88 , 7,12±1,88). According to the multiple regression analyze, age and living area has effects on the impact. The frequencies of the CA found higher but not significant in exposed group than controls, respectively (0,71±0,94, 0,49±0,71). When we compare repair capacitie % percentages of the groups in 20th and 60th minutes, exposed population has significantly lower levels then control group. We found that, % repair capacities of 20th and 60th minutes are not affected by risk factors according to the multiple regressions. The genotoxic susceptibility to H2O2 treatment was found to be not-significantly higher in exposed group than control group respectively (13,46±4,36, 12,48±4,26). The mean levels for 1-OHP for exposed group was found significantly higher than (p<0,001) controls, respectively (0,42±0,13, 0,25±0,07)

Compare of transparented leaf method and nail polish method in determination of stomatal density in grapevine

Bu araştırmada Tekirdağ Bağcılık Araştırma İstasyonu arazisinde bulunan kültür asması çeşitlerinden Semillon, Narince, Gamay, Michele Paleri ve Çavuş ile 3309 Coudere, SO4, 5BB, 41B, 1103P anaç çeşitlerinin güneş gören ve gölgede olan yapraklarında stoma yoğunluğunun kalıp alma ve saydamlaştırma yöntemleri kullanılarak belirlenmesi ve yöntemlerin karşılaştırılması amaçlanmıştır. Kültür asması ve anaç çeşitlerinin güneş gören ve gölgede olan sürgünlerinden, 4. ile 5. boğumlarında gelişmesini tamamlamış ve katılaşmamış, hastalıksız ve çeşide özgü normal formda olan yapraklardan alınan örnekler saydamlaştırma yöntemi ve kalıp alma yöntemi ile incelenmiştir. İnceleme sonucunda kültür çeşitleri arasında stoma sayıları güneş gören yaprakta 1 mm2 ’de 276.04 ± 5.31 ile 170.58 ± 4.03 stoma/mm2 arasında, gölgede olan yaprakta ise 1mm2 'de 194.27 ± 16.83 ile 155.49 ± 7.43 stoma/mm2 arasında değişim göstermiştir. Anaçlarda ise stoma sayıları güneş gören yaprakta 1 mm 2 ’de 256.25 ± 15.83 ile 172.27 ± 3.55 stoma/mm2 arasında, gölgede olan yapakta ise 1mm2 'de 210.94 ± 22.63 ile 150.54 ± 8.80 stoma/mm2 arasında bulunmuştur. Saydamlaştırma yönteminde, aynı çeşidin güneş gören ve gölgede olan yaprakları arasında stoma sayısı açısından bir faklılığın izlendiği, güneş gören yapraklarda stoma sayısının daha fazla olduğu ve bu farklılığın kalıp alma yönteminde de saptandığı görülmüştür. Benzer farklılıklar hem çeşitlerde hem de anaçlarda saptanmıştır. İki yöntemi karşılaştırdığımızda hem çeşitlerde hemde anaçlarda, saydamlaştırma yönteminde, birim alanda saptanan stoma sayısının daha fazla olduğu, bu yöntemin kalıp alma yöntemine göre daha güvenilir bir yöntem olduğu sonucuna varılmıştır.In this research, it was aimed to determine stoma density of Semillon, Gamay, Narince, Michele Paleri, Çavuş cultivars and 3309 C, SO4, 5BB, 41B, 1103P rootstocks leaves which was in sunlight and in shade located in Tekirdağ Viticulture Research Station. Two methods were used; transparented leaf method and nail polish method. Two methods were compared in point of stomal density. Stomal density changed between cultivars in sunlight between 276.04 ± 5.31 and 170.58 ± 4.03 stoma/mm2 and in shaded leaves between 194.27 ± 16.83 and 155.49 ± 7.43 stoma/mm2 . Stomal density changed in rootstocks in sunlight between 256.25 ± 15.83 and 172.27 ± 3.55 stoma/mm2 , and in shaded leaves between 210.94 ± 22.63 ile 150.54 ± 8.80 stoma/mm2 . No differences were found between cultivars and rootstocks with transparented leaf method in terms of the number of stomata in shaded leaves and sunlight exposed leaves. Same results found with nail polish method. When we compare this two methods, in cultivars and rootstocks, in sunlight exposed leaves the stomal density were found much more than in shaded leaves. Consequently, it was found that determining stomal density with using transparanted leaf methot was more reliable than nail polish method