30 research outputs found

    Brane World Cosmology In Jordan-Brans-Dicke Theory

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    We consider the embedding of 3+1 dimensional cosmology in 4+1 dimensional Jordan-Brans-Dicke theory. We show that exponentially growing and power law scale factors are implied. Whereas the 4+1 dimensional scalar field is approximately constant for each, the effective 3+1 dimensional scalar field is constant for exponentially growing scale factor and time dependent for power law scale factor.Comment: 11 page

    Higher Dimensional Cylindrical or Kasner Type Electrovacuum Solutions

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    We consider a D dimensional Kasner type diagonal spacetime where metric functions depend only on a single coordinate and electromagnetic field shares the symmetries of spacetime. These solutions can describe static cylindrical or cosmological Einstein-Maxwell vacuum spacetimes. We mainly focus on electrovacuum solutions and four different types of solutions are obtained in which one of them has no four dimensional counterpart. We also consider the properties of the general solution corresponding to the exterior field of a charged line mass and discuss its several properties. Although it resembles the same form with four dimensional one, there is a difference on the range of the solutions for fixed signs of the parameters. General magnetic field vacuum solution are also briefly discussed, which reduces to Bonnor-Melvin magnetic universe for a special choice of the parameters. The Kasner forms of the general solution are also presented for the cylindrical or cosmological cases.Comment: 16 pages, Revtex. Text and references are extended, Published versio

    An Autonomous Interface Circuit Based on Self-Investing Synchronous Energy Extraction for Low Power Piezoelectric Energy Harvesters

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    This paper presents a self-powered interface circuit to rectify and manage the AC output of the piezoelectric energy harvesters (PEH) by utilizing Self-Investing Synchronous Electric Charge Extraction technique (SI-SECE). The system invests charges from the battery to PEH to improve the electromechanical coupling factor and consequently the energy extraction by utilizing only one external component. The circuit was implemented in 180 nm CMOS technology where high voltage (HV) MOS transistors are utilized to tolerate high open circuit output voltages of PEHs. MEMS PEH with 4.7 nF inherent capacitance has been used to charge a 1 mu F storage capacitor. Proposed interface circuit extracts 18.55 mu W that is 33 % more than traditional SECE (13.95 mu W) for 250 Hz PEH excitation frequency and 2.3 V piezoelectric open circuit voltage amplitude. At the output power of 48.5 mu W, maximum power conversion efficiency of 62.4% is achieved as charge investment and corresponding conduction and switching losses on investing transistors. SI-SECE delivers power with 4.5x relative performance improvement over on-chip full-bridge rectifier

    First Report of Canker and Dieback Caused by Botryosphaeria dothidea on Apple in Turkey.

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    WOS: 000375634200040Apple is one of the most commercially profitable fruit crops in Turkey, and is grown on 150,847 ha with 2,889,000 tons of fruit produced annually. In June 2015, we observed trees with sunken and reddish-brown limb cankers. Blighted shoots had circular spots or blisters around lenticels with lesions extending along the entire branch, often leading to bark cracking. More than 20% of the 8-year-old apple trees (Malus domestica Borkh) in a 15-ha orchard (37°59ʹ29ʺ N; 38°02ʹ11ʺ E) near Malatya planted with ‘Golden Delicious’ were affected. Samples from the inner cambium from cankered branches were collected from declining trees, surface sterilized in 70% ethanol, plated on potato dextrose agar (PDA), and incubated at 22°C..

    Demodex spp. Infestation in a breast-cancer patient: A case report

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    Demodex folliculorum and Demodex brevis are obligatory parasites that live in sebaceous glands and follicles. When immune system becomes suppressed by any reason, patients become vulnerable to obligatory parasites like D. folliculorum and D. brevis. Immune system becomes suppressed in cancer patients who undergo chemotherapy, and as a result these patients become vulnerable to infestations. In our case, a 45 year-old female has been admitted to oncology clinic for a medical treatment of breast cancer. Her systematic physical examination was normal, except redness on her cheeks and forehead. There was no abnormality in biochemical and haematological laboratory values. We have decided to apply chemotherapy of Adriamycin, cyclophosphamide and 5-fluorouracil. Due to the itchy redness on her cheeks and forehead, we had performed an examination for demodex before chemotherapy; and we have identified 20 mites/cm² on her right and left cheeks, and 15 mites/cm² on her forehead. When our patient had came our clinic with increasing complaint of itchy rash, after the first course of chemotherapy we have reexamined demodex. The result of microscopic examination revealed large amount of demodex of 50 mites/cm² on her right and left cheeks and 30 mites/cm² on her forehead, which were nearly 2.5-times higher than the previous examination. This increase probably was associated with immune suppression of chemotherapy.Keywords: Chemotherapy, demodex, infestatio

    Curcumin abates formaldehyde-induced neurotoxicity via NO pathway and the change of minerals (calcium, iron, zinc, copper, magnesium) in brain tissue

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    Oxidative stress has been defined as an imbalance between higher cellular levels of reactive oxygen species (ROS). If ROS are not controlled by enzymatic and non-enzymatic antioxidants, they can cause oxidative injury. Brains are protected by antioxidants from nitro-oxidative and peroxidative damage. The antioxidant enzymes are superoxide dismutase and catalase, which contain zinc (Zn) and copper (Cu) as cofactors. Also, trace elements have important effects on brain development and function. In this study, we aimed to investigate the effect of curcumin administration on the exchange of nitric oxide (NO) and on the calcium (Ca), iron (Fe), Zn, Cu, and magnesium (Mg) levels in brain tissue. Animals (a total of 30 adult Wistar albino rats, 4-6 months old) were randomly divided into three groups (n = 10): control, formaldehyde-exposed, and treated daily with curcumin after formaldehyde exposure (100 mg kg-1). At the end of the experimental period (the 14th day), NO levels were measured by ELISA. Ca, Fe, Zn, Cu, and Mg levels in whole-brain tissues were determined by Atomic Absorption Spectrophotometry in all groups. NO and Mg levels were increased and Cu and Ca levels were decreased in the group treated with curcumin when compared with the formaldehyde-only group. These changes were not statistically significant (P > 0.05). However, Fe levels were significantly reduced and Zn levels were significantly increased (P < 0.05). In conclusion, the administration of curcumin as an antioxidant may be a factor in regulating the mineral balance of the brain in conditions of oxidative stress caused by the application of FA. Curcumin may play a role in reducing FA-induced cellular damage, and may contribute to the treatment of neurodegenerative diseases such as Alzheimer’s and Parkinson’s

    Curcumin abates formaldehyde-induced neurotoxicity via NO pathway and the change of minerals (calcium, iron, zinc, copper, magnesium) in brain tissue

    No full text
    Oxidative stress has been defined as an imbalance between higher cellular levels of reactive oxygen species (ROS). If ROS are not controlled by enzymatic and non-enzymatic antioxidants, they can cause oxidative injury. Brains are protected by antioxidants from nitro-oxidative and peroxidative damage. The antioxidant enzymes are superoxide dismutase and catalase, which contain zinc (Zn) and copper (Cu) as cofactors. Also, trace elements have important effects on brain development and function. In this study, we aimed to investigate the effect of curcumin administration on the exchange of nitric oxide (NO) and on the calcium (Ca), iron (Fe), Zn, Cu, and magnesium (Mg) levels in brain tissue. Animals (a total of 30 adult Wistar albino rats, 4-6 months old) were randomly divided into three groups (n = 10): control, formaldehyde-exposed, and treated daily with curcumin after formaldehyde exposure (100 mg kg-1). At the end of the experimental period (the 14th day), NO levels were measured by ELISA. Ca, Fe, Zn, Cu, and Mg levels in whole-brain tissues were determined by Atomic Absorption Spectrophotometry in all groups. NO and Mg levels were increased and Cu and Ca levels were decreased in the group treated with curcumin when compared with the formaldehyde-only group. These changes were not statistically significant (P > 0.05). However, Fe levels were significantly reduced and Zn levels were significantly increased (P < 0.05). In conclusion, the administration of curcumin as an antioxidant may be a factor in regulating the mineral balance of the brain in conditions of oxidative stress caused by the application of FA. Curcumin may play a role in reducing FA-induced cellular damage, and may contribute to the treatment of neurodegenerative diseases such as Alzheimer’s and Parkinson’s
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