Printed graphene films with positive temperature coefficient of resistivity

0.5μm thick graphene films printed on plastic substrates exhibit metallic type conduction with a positive value of 1.5×〖10〗^(-3) K^(-1) for the temperature coefficient of resistance over the temperature range from 260K to 330K . The crystallites of approximately 6.5 nm in their average size in the film are found from the X-Ray diffraction pattern to be oriented preferentially along [002] plane.Dr. Indrani Banerjee is grateful to Commonwealth Association, UK for funding the present research work under the fellowship placement scheme (grant reference INCF-2014-66). The studentship of Ms Faris is partially sponsored by the Air Force Office of Scientific Research, Air Force Material Command, USAF, under Grant No. FA8655-08-1-3056

On R-duals and the duality principle in Gabor analysis

The concept of R-duals of a frame was introduced by Casazza, Kutyniok and Lammers in 2004, with the motivation to obtain a general version of the duality principle in Gabor analysis. For tight Gabor frames and Gabor Riesz bases the three authors were actually able to show that the duality principle is a special case of general results for R-duals. In this paper we introduce various alternative R-duals, with focus on what we call R-duals of type II and III. We show how they are related and provide characterizations of the R-duals of type II and III. In particular, we prove that for tight frames these classes coincide with the R-duals by Casazza et el., which is desirable in the sense that the motivating case of tight Gabor frames already is well covered by these R-duals. On the other hand, all the introduced types of R-duals generalize the duality principle for larger classes of Gabor frames than just the tight frames and the Riesz bases; in particular, the R-duals of type III cover the duality principle for all Gabor frames

Graphene films printable on flexible substrates for sensor applications

Fifteen-layered graphene films have been successfully deposited onto flexible substrates using a commercial ink consisting of graphene particles dispersed in an acrylic polymer binder. A value of 74.9 × 105cm−2 was obtained for the density of defects, primarily located at the flake edges, from the ratio of the D and G Raman peaks located at 1345cm1 and 1575cm1 respectively. 0.5μm thick drop-cast films on interdigitated silver electrodes exhibited Ohmic conduction with a small activation energy of 12meV over the temperature range from 260K to 330K . The photo-thermoelectric effect is believed to be responsible for photoconduction through graphene films under illumination intensity of 10mWm-2 at 270 nm, corresponding to the UV absorption peak. The photo-transient decay at the bias of 1V involves two relaxation processes when the illumination is switched off and values of 8.9 × 103 and 4.3 × 104 are found for the relaxation time constant using the Kohlrauch stretched exponential function analysis.Dr. Indrani Banerjee is grateful to Commonwealth Association, UK for funding the present research work under the fellowship placement scheme (Grant reference INCF-2014-66). The studentship of Ms Faris is partially sponsored by the Air Force Office of Scientific Research, Air Force Material Command, USAF, under Grant No. FA9550-15-1-0123. We are also thankful to Miss V. M. Torrejon of Brunel University for support in computer graphics

DYNAMICS OF THE RADIOACTIVE POLLUTION IN THE SURFACE LAYER OF SOILS IN BULGARIA TWENTY YEARS AFTER THE CHERNOBYL NUCLEAR POWER PLANT ACCIDENT

The twenty years period past after the contamination with radionuclides in 1986, as a result of the accident in the Chernobyl’s NPP, allowed the accumulation of rich data base for the radiation status of the soils in Bulgaria. Objective of many years studies were virgin soils from high mountain areas, hilly and flat (the region of Kozlodouy NPP and the Danube river valley). Ceasium-137 and strontium-90 were the main men-made radionuclides detected in the examined Bulgarian soils, few years after the accident. The content of ceasium-137 and strontium-90 in the soils from high mountain areas (Rodopa and Rila mountains) is several times higher then that in the soils from Northern Bulgaria and Sofia field. High non-homogeneity in the pollution within small areas (scores of square meters even) was determined. No significant horizontal redistribution was observed for the period after 1986. The tendency of changes in the radioactive status of the soils in Bulgaria after the accident at the Chernobyl Nuclear Power Plant is not due to trans-border transfer of radioactive materials or to any breakdown at the Kosloduy Nuclear Power Plant.Изминалият двадесетгодишен период след масираното отлагане на радионуклиди през 1986 година, като резултат от аварията в Чернобилската АЕЦ, даде възможност да бъде натрупана богата база данни за радиационния статус на почвите в България. Обект на дългогодишни изследвания бяха целинни почви от високопланински райони, полупланински и равнинни (района на АЕЦ “Козлодуй” и поречието на р. Дунав. Няколко години след инцидента цезий- 137 и стронций-90 са основните техногенни радионуклиди се детектират в изследваните български почви. Съдържанието на цезий-137 и стронций-90 в почвите от високопланинските райони (Родопите и Рила планина) е неколкократно по-високо от това в Северна България и Софийското поле. Установенеа бе силна нехомогенност на замърсяването, дори в рамките на малки площи (десетки квадратни метра). За периода след 1986 година не се наблюдав значимо хоризонтално преразпределение. Тенденциите в изменението на радиационния статус на почвите в България след авариятав Чернобилската АЕЦ не се дължат на трансграничен пренос на радиоактивни материали или някакво нарушение в дейността на АЕЦ Козлодуй

Nutrigenomics: DNA-based individualized nutrition

In the past decade, nutrition research has undergone an important shift from epidemiology and physiology to molecular biology, adipobiology and genetics, thus launching the science of nutrigenomics. To at molecular level study effects of nutrition on health and disease. The completion of several large genome projects has markedly altered the research agenda by drawing attention to the importance of genes in human nutrition. There has been a growing recognition that micronutrients and macronutrients can be potent dietary signals that influencethemetabolic pathways of cells and have an important role in the control of energy, vascular and neuronal homeostasis. Accordingly, nutrition researchers have increasingly started to recognize that gene-environment interactions can be implicated in the pathogenesis of lifestyle-related diseases, particularly cardiometabolic diseases, fatty liver diseases, cancers, and Alzheimer's disease. An adiponutrigenomic insight into life expectancy is also outlined. Overall, the present Dance Round focuses on a mater of nationwide importance for Bulgaria, a country at the epicenter of today's global healthquake, the obesity and related diseases.Biomedical Reviews 2006; 17: 117-122

Effect of arsenic-phosphorus interaction on arsenic-induced oxidative stress in chickpea plants

Arsenic-induced oxidative stress in chickpea was investigated under glasshouse conditions in response to application of arsenic and phosphorus. Three levels of arsenic (0, 30 and 60 mg kg−1) and four levels of P (50, 100, 200, and 400 mg kg−1) were applied to soil-grown plants. Increasing levels of both arsenic and P significantly increased arsenic concentrations in the plants. Shoot growth was reduced with increased arsenic supply regardless of applied P levels. Applied arsenic induced oxidative stress in the plants, and the concentrations of H2O2 and lipid peroxidation were increased. Activity of superoxide dismutase (SOD) and concentrations of non-enzymatic antioxidants decreased in these plants, but activities of catalase (CAT) and ascorbate peroxidase (APX) were significantly increased under arsenic phytotoxicity. Increased supply of P decreased activities of CAT and APX, and decreased concentrations of non-enzymatic antioxidants, but the high-P plants had lowered lipid peroxidation. It can be concluded that P increased uptake of arsenic from the soil, probably by making it more available, but although plant growth was inhibited by arsenic the P may have partially protected the membranes from arsenic-induced oxidative stress

Frame Theory for Signal Processing in Psychoacoustics

This review chapter aims to strengthen the link between frame theory and signal processing tasks in psychoacoustics. On the one side, the basic concepts of frame theory are presented and some proofs are provided to explain those concepts in some detail. The goal is to reveal to hearing scientists how this mathematical theory could be relevant for their research. In particular, we focus on frame theory in a filter bank approach, which is probably the most relevant view-point for audio signal processing. On the other side, basic psychoacoustic concepts are presented to stimulate mathematicians to apply their knowledge in this field

Preliminary data on COVID-19 in patients with hemoglobinopathies : A multicentre ICET-A study

Objectives: This study aims to investigate, retrospectively, the epidemiological and clinical characteristics, laboratory results, radiologic findings, and outcomes of COVID-19 in patients with transfusion-dependent β thalassemia major (TM), β-thalassemia intermedia (TI) and sickle cell disease (SCD). Design: A total of 17 Centers, from 10 countries, following 9,499 patients with hemoglobinopathies, participated in the survey. Main outcome data: Clinical, laboratory, and radiologic findings and outcomes of patients with COVID-19 were collected from medical records and summarized. Results: A total of 13 patients, 7 with TM, 3 with TI, and 3 with SCD, with confirmed COVID-19, were identified in 6 Centers from different countries. The overall mean age of patients was 33.7±12.3 years (range:13-66); 9/13 (69.2%) patients were females. Six patients had pneumonia, and 4 needed oxygen therapy. Increased C-reactive protein (6/10), high serum lactate dehydrogenase (LDH; 6/10), and erythrocyte sedimentation rate (ESR; 6/10) were the most common laboratory findings. 6/10 patients had an exacerbation of anemia (2 with SCD). In the majority of patients, the course of COVID-19 was moderate (6/10) and severe in 3/10 patients. A 30-year-old female with TM, developed a critical SARS-CoV-2 infection, followed by death in an Intensive Care Unit. In one Center (Oman), the majority of suspected cases were observed in patients with SCD between the age of 21 and 40 years. A rapid clinical improvement of tachypnea/dyspnea and oxygen saturation was observed, after red blood cell exchange transfusion, in a young girl with SCD and worsening of anemia (Hb level from 9.2 g/dl to 6.1g/dl). Conclusions: The data presented in this survey permit an early assessment of the clinical characteristics of COVID 19 in different countries. 70% of symptomatic patients with COVID-19 required hospitalization. The presence of associated co-morbidities can aggravate the severity of COVID- 19, leading to a poorer prognosis irrespective of age

The nucleotide addition cycle of RNA polymerase is controlled by two molecular hinges in the Bridge Helix domain

Abstract Background Cellular RNA polymerases (RNAPs) are complex molecular machines that combine catalysis with concerted conformational changes in the active center. Previous work showed that kinking of a hinge region near the C-terminus of the Bridge Helix (BH-HC) plays a critical role in controlling the catalytic rate. Results Here, new evidence for the existence of an additional hinge region in the amino-terminal portion of the Bridge Helix domain (BH-HN) is presented. The nanomechanical properties of BH-HN emerge as a direct consequence of the highly conserved primary amino acid sequence. Mutations that are predicted to influence its flexibility cause corresponding changes in the rate of the nucleotide addition cycle (NAC). BH-HN displays functional properties that are distinct from BH-HC, suggesting that conformational changes in the Bridge Helix control the NAC via two independent mechanisms. Conclusions The properties of two distinct molecular hinges in the Bridge Helix of RNAP determine the functional contribution of this domain to key stages of the NAC by coordinating conformational changes in surrounding domains.</p