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

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

Restaging role of 18F-FDG-PET/CT in a patient with a Malignant Peripheral Nerve Sheath Tumor (MPNST) caused by neurofibromatosis – case report

Malignant Peripheral Nerve Sheath Tumors (MPNST) are a malignant disease that originates in the cells that cover and protect the peripheral nerves. They are a rare disease, accounting for 6% of soft tissue sarcomas. We present a patient with a malignant peripheral nerve sheath tumor on the left brachium with neurofibromatosis. The patient underwent whole body PET/CT for restaging after total extirpation of a tumor formation originated from n. musculocutaneous in 09.2017, an excision of a recurrent tumor formation in the proximal half of the brachium invading into m. biceps brachii in 12.2017, a performed MRI in 02.2018 - with data for multiple MPSNT in the area between the two previous operations - and subsequent definitive radiotherapy (boost) in the area of the tumor formation and 6 cycles of chemotherapy with Epirubicin. After restaging PET/CT scan of the whole body was performed, progression of the disease was defined - increased in size and activity subpleural lesion in the lower lobe of the right lung

ЕФЕКТ НА ЕКЗОГЕННИЯ ПОЛИАМИН ДИЕТИЛЕНТРИАМИН ВЪРХУ ОКСИДАТИВНИТЕ ПРОМЕНИ И ФОТОСИНТЕЗАТА В ТРЕТИРАНИ С АРСЕН ЦАРЕВИЧНИ РАСТЕНИЯ (Zea mays L.)

The antioxidant effect of the exogenous polyamine Diethylentriamine (DETA) on the oxidative changes in young maize plants treated with different As concentrations was studied. The plants were grown in a climatic box in a Hogland-Arnon nutrient solution. Arsenic was applied as Na3As04 in concentrations 0, 2 and 5 mg dm-3 (pH 5.5). The polyamine DETA (concentration 10-4 М) was added to the nutrient environment of some of the plants 24 hours prior to the As treatment. Five days later the lipid peroxidation level, the peroxidase activity, the growth and leaf gasexchange, and the protein and plastid pigments content were studied. The physiological analyses proved that DETA had positive effect on the As-treated maize plants by increasing the leaf gas-exchange, the plastid pigments content and soluble protein. The exogenous polyamine DETA, applied 24 hours prior to the As treatment, decreased considerably the lipid peroxidation level and the peroxidase itself in maize plants. DETA had protective effect on the As-induced oxidative stress, but in order to clarify its role as an antioxidant, more detailed and profound studies should be made.Проучен беше aнтиоксидантният ефект на екзогенния полиамин Диетилентриамин (ДЕТА) върху оксидативните промени в млади царевични растения, третирани с различни концентрации арсен. Растенията бяха отгледани в климатичен бокс в хранителна среда на Хогланд-Арнон. Арсенът (As) беше приложен като Na3As04 в концентрации 0, 2 и 5 mg dm-3 (pH 5.5). Полиаминът ДЕТА (концентрация 10-4 М), беше прибавен към хранителната среда на част от растенията 24 h преди третирането с Аs. След пет дни беше отчетено нивото на липидната пероксидация, активността на ензима пероксидаза, растежът и листният газообмен, и съдържанието на белтък и пластидни пигменти. Физиологичните анализи показаха, че полиаминът Дета оказва положителен ефект върху третираните с арсен царевични растения, като повишава листния газообмен, съдържанието на пластидни пигменти и разтворим белтък. Екзогенният полиамин Дета, приложен 24 преди третирането с As намалява съществено нивото на липидната пероксидация и ензима пероксидаза в царевичните растения. Изследванията показват, че ДЕТА изпълнява протекторен ефект срещу As-индуцирания оксидативен стрес, но за изясняване на неговата роля като антиоксидант са необходими по-детайлни и задълбочени изследвания

Monitoring the effect of therapy on a patient with a neuroendocrine tumor of the pancreas with PET/CT, 68Ga-DOTATATE - case report

Neuroendocrine tumors (NET) are a rare diagnosis, often without symptoms or mimicking other different symptoms. Тhey are a heterogeneous group of tumors derived from neuroendocrine cells, most commonly of the gastrointestinal tract, but may originate also from other organs including the pancreas, lungs, ovaries, thyroid, pituitary, and adrenal glands (3). Due to the difficult diagnosis, NET‘s are detected at a late stage in their development, often already locally advanced or metastasized. PET/CT with 68Gallium DOTATATE proved to be an effective imaging method not only for the primary diagnosis of NET and subsequent therapeutic behavior, but also for evaluating the effect of the treatment. (1) We present a case of a positive PET/CT scan, performed with Ga-68 DOTATATE in the topical location of the tail of the pancreas after therapy with Sandostain lar

Graphene-based strain sensing in composites for structural and health monitoring applications

Copyright © 2022 The Author(s). Composite structures are attracting more interest due to their outstanding mechanical properties; thus, their inspection and health assessment are key items for their safe use. In this article we present a graphene-based sensor that evaluates the strain generated within a composite. A finite element model was developed to investigate the mechanism driving the graphene to act as a strain sensor. A prototype sensor was manufactured, using a commercially available graphene ink. The strain in composite samples was measured and the gauge factor identified by applying different load scenarios. The graphene sensor proved to be able to evaluate strain at various levels providing a gauge factor (exceeding 6) higher than commercially available strain gauges.Innovate UK for the project GRAPHOSITE “A Graphene Sensor for Defect Detection and Predictive Maintenance in Composite Materials” [grant number 104266]

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