bluuebunny/crossref_metadata_2025 huggingface dataset:
Dihydroneopterin as a scavenger of nitrogen centered radicals
Authors: Oettl Karl , Greilberger Joachim , Reibnegger Gilbert
Published: March 2013

Dihydroneopterin has recently been shown to either promote or decrease formation of free radicals or radicalmediated reactions, depending on the conditions. We report here the scavenging activity of dihydroneopterin on nitrogen centered radicals. Diphenylpicrylhydrazyl (DPPH) and tl. e radical cation of 2,2' -azino-di-[3- ethylbenzthiazoline sulphonate] (ABTS) were used. Dihydroneopterin showed scavenging properties against either compound. In the case of DPPH radical scavenging by dihydroneopterin was comparable with trolox. In the ABTS system, dihydroneopterin had an even better capacity of radical scavenging as compared to trolox .
Impairment of Lipid Metabolism Due to Deficiency of Pyridoxal-5-phosphate and/or Activated Immune system: its Interpretation
Authors: Rudzite Vera , Jurika Edite , Jäger Matthias , Fuchs Dietmar
Published: March 2013

Impairment of lipid metabolism due to excess metabolite accumulation induced by pyridoxal-5-phosphate (P-5-P)-deficiency and/or stimulated immune system has been studied and interpreted. Decreased amounts of phospholipids as well as deviations in phospholipid classes and fatty acid composition of phospholipids have been demonstrated due to kynurenine accumulation in the blood of P-5-P-deficient cardiovascular patients and white rats as well as in cardiovascular patients with activated immune system identified by an increased neopterin concentration in the blood (dilated cardiomyopathy). The addition of P-5-P to the incubation medium for phospholipid biosynthesis in vitro did not change fatty acid incorporation into phospholipids, whereas it normalised fatty acid incorporation into phospholipids in liver homogenates received from P-5-P-deficient rats: The addition of kynurenine, neopterin and noradrenalin (accumulated m isolated heart tissue after addition of kynurenine and neopterin to incubation medium for isolated heart) to incubation medium for phospholipid biosynthesis in vitro induced an increase of saturated and a decrease of polyunsaturated fatty acid incorporation into phospholipids. These changes in fatty acid incorporation into phospholipids were followed by increased cholesterol concentrations in samples and an increased cholesterol/phospholipid ratio. Our results suggest that these changes in lipids are characteristic for decreased membrane fluidity, depressed cell cycle and lowered possibility of phospholipids to keep cholesterol in solution. P-5-P-deficiency is also accompanied with excess accumulation of homocysteine in the blood. The addition of L-homocysteine to the incubation medium for phospholipid biosynthesis in vitro was followed by inverse changes in fatty acid incorporation into phospholipids when compared with kynurenine, neopterin and noradrenalin. L-homocysteine induced a decrease of saturated and an increase of polyunsaturated fatty acid incorporation into phospholipids. The cholesterol concentration decreased in samples and the cholesterol/ phospholipid ratio decreased, too . These findings suggest that changes in lipids induced by L-homocysteine are characteristic for increased membrane fluidity and stimulated cell cycle. In this study, we have observed a similar effect to L-homocysteine effect when L-homocysteine, L-tryptophan and 5,6,7,8-tetrahydrobiopterin were added to the incubation medium for phospholipid biosynthesis in vitro. The comparison of our results with data from the literature allows to suggest that excess metabolite accumulation due to activated formation and inactivated catabolism of it plays a significant role in quantitative and qualitative changes of lipids, especially phospholipids, and therefore participates in the regulation of membrane fluidity, cell cycle of normal and malignant cells as well as in keeping cholesterol in the state of solution.
A Case of Dihydropteridine Reductase Deficiency
Authors: Furujo Mahoko , Ichiba Yozo , Sintaku Haruo , Asada Minoru
Published: March 2013

Tetrahydrobiopterin (BH4) is the essential cofacter of phenylalanine (Phe), tyrosine (Tyr), and tryptophan (Trp) hydroxylases . BH4 deficiency, a rare but severe type of hyperphenylalaninemia, is characterized by progressive neurologic symptoms despite early detection and treatment with a Phe-restricted formula. An expensive dose of BH4 is needed to keep with the Phe, Tyr and Trp hydroxylation reaction. Severe BH4 deficiency is a naturally occurring model of cerebral catecholamine and serotonin shortage. Here we present a patient in which the hyperpheny lalaninelTIia could be reversed with BH4 therapy, but the concentrations of homo vanillic acid (HVA ) and 5- hydroxy indole acetic acid (5HIAA) in cerebrospinal fluid (CSF) remained low. Administration of the neurotransmitter precursors iL-DOPA/carbidopa and 5-hydroxytryptophan jappeared to be the most effective treatment and may prevent neurological damage if started early in life
Stimulation of Tetrahydrobiopterin Synthesis by 17β-Estradiol in Brain Microvascular Endothelial Cells
Authors: Shiota Kazuhiro , Ishii Masakazu , Yamamoto Toshinori , Shimizu Shunichi , Kiuchi Yuji
Published: March 2013

The purpose of this study was to examine whether 17β-estradiol stimulates the synthesis of tetrahydrobiopterin : BH4), which is one of the cofactors of nitric oxide (NO) synthase, in mouse brain microvascular endothelial cells. Addition of 17()-estradiol to endothelial cells time- and concentration-dependently increased intracellular BH4 level. 17β-Estradiol also stimulated the mRNA level of GTP-cyclohydrolase I (GTPCH), which is a rate-limiting enzyme of the de novo BH4 synthetic pathway. In addition, the 17β-estradiol-induced expression of GTPCH mRNA was strongly attenuated by treatment with an inhibitor of 17β-estradiol receptor 4-hydroxy-tamoxlfen. These results suggest that 17β-estradiol stimulates BH4 synthesis through the induction of GTPCH by tamoxifensensitive receptor in vascular endothelial cells. The 17β-estradiol-induced increase in BH4 level might be implicated in not only NO production, but also protective effects of 17β-estradiol against ischemic brain damage and atherosclerosis, since BH4 is an intracellular antioxidant.
Serum Neopterin Levels in Renal Cell Carcinoma
Authors: Yoshida Naomasa , Ikemoto Shinichi , Narita Keisuke , Sugimura Kazunobu , Wada Seiji , Yasumoto Ryouji , Nakatani Tatsuya
Published: March 2013

Concentrations of neopterin, which is produced by human monocytesl macrophages when stimulated by interferon- γ, were measured in serum specimens from 109 patients with renal cell carcinoma (RCC). Results showed that neopterin levels were significantly higher in the patients with grade 3 RCC compared to the control subjects and patients with grade 1 or grade 2 RCC. When the patients were divided according to serum C-reactive protein (CRP), neopterin levels were significantly higher in the CRP-positive patients compared to the control subjects and CRP-negative patients. A significant correlation was shown between serum neopterin levels and CRP. Our study suggests that serum neopterin levels may supplement laboratory examinations for patients wilh RCC, providing useful information in evaluating the tumor stage and follow-up of the disease.
Troglitazone Stimulates the Insulin-induced Tetrahydrobiopterin Synthesis In Vascular Endothelial Cells
Authors: Ishii Masakazu , Shimizu Shunichi , Shiota Kazuhiro , Kiuchi Yuji , Yamamoto Toshinori
Published: March 2013

We investigated the effects of troglitazone, which is a ligand of nuclear transcription factor peroxisome proliferator- activated receptor-γ (PPAR-γ), on insulin-induced tetrahydrobiopterin (BH4) synthesis in mouse brain microvascular endothelial cells (MBMECs). BH4 content was determined as biopterin, by reversed-phase high performance liquid chromatography using fluorometric detection. Measurement of mRNA level of GTP cyclohydrolase I (GTPCH), which is a rate-limiting enzyme for de novo BH4 synthesis, was performed by reverse transcription- polymerase chain reaction (RT -PCR). Addition of insulin (10µg/ml) to endothelial cells increased intracellular BH4 content and GTPCH mRNA level, and the insulin-induced increase in BH4 content and GTPCH mRNA level was further stimulated by co-treatment with troglitazone (0.3-3 µM). However, the expression of PPAR-γ mRNA in untreated and insulin-treated endothelial cells was not detected. Moreover, bezafibrate (1-10 µM), a ligand of PPAR-δ, did not affect BH4 synthesis in insulin-treated endothehal cells. These findings suggest that troglitazone stimulates insulin-induced BH4 synthesis in endothelial cells with the induction of GTPCH through PPAR-γ- and PPAR-δ-independent mechanism
Neopterin and Cytokines in Non-pleocytotic Cerebrospinal Fluid in Child Patients
Authors: Kawakami Yasuhiko , Kuwabara Kentaro , Fujita Takehisa , Fujino Osamu , Fukunaga Yoshitaka
Published: March 2013

CSF and serum levels of neopterin and several kinds of CSF cytokines were measured in child patients with non-pleocytotic CSF. The CSF neopterin levels with febrile convulsions (FCs) were 27.4±33.0 nmol/1 and the CSF neopterinlserum neopterin ratio (C/S ratio) with FCs was 2.07±2.06. The longer the FCs patients' convulsions lasted, the higher their CSF neopterin levels tended to be come. The CSF neopterin levels with FCs were significantly higher than in those with pyrexia without convulsions (6.5±2.5 nmol/L) or convulsions without pyrexia, including epilepsy (4.9±2.9 nmol/L). The C/S ratio was also higher in patients with FCs than in those with pyrexia without convulsions (0.31±0.17) or convulsions without pyrexia (0.82±0.50).In addition, there was a tendency for CSF IFN-γ levels to be higher in patients with FCs than in those with pyrexia without convulsions or convulsions without pyrexia. However, TNF-α and IL-1α were under measurable levels in cases of non-pi eocytotic CSF. The CSF neopterin levels in patients with exanthem subitum with FCs were higher than in those without FCs. It has been reported that there is a possibility of neopterin production by microglial cells. Our finding that CSF neopterin levels were elevated in patients with FCs, whose CSF had no pleocytosis, are consistent with the possibility of neopterin production by microglia. Our results further suggest that immune activation of microgrial cells is one of the mechanisms involved in the onset of FCs.
Chemical structure of 1-O-(L-erythro-biopterin-2'-yl)-a-glucose isolated from a cyanobacterium Synechococcus sp. PCC 7942
Authors: Choi Yong Kee , Hwang Yoon Kyung , Kang Yong Han , Park Young Shik
Published: March 2013

Abstract A pteridine glycoside in Synechococcus sp. PCC 7942, the structure of which had been tentatively identified as biopterin-glucoside, was isolated and characterized for its exact chemical structure by 2D-NMR spectroscopy. The determined structure is 1-0-(L-erythro-biopterin-2'-yl)-α-glucose. It is the first report on the occurrence of a biopterin-glucoside having a α-configured sugar directly attached at the pteridine ring. This result also supports that the previously purified UDP-glucose: BH4 glucosyltransferase from Synechococcus sp. PCC 7942, which catalyzes the synthesis of BH4-glucoside from UDP-glucose and BH4, is a α-glucosyltransferase.
Association between increased serum neopterin and homocysteine concentrations as well as pyridoxal-5-phosphate deficiency in patients with coronary heart disease
Authors: Rudzite Vera , Silava Anita , Kalnins Uldis , Erglis Andrejs , Jäger Matthias , Trushinskis Karlis , Fuchs Dietmar
Published: March 2013

Abstract Concentrations of serum neopterin and homocysteine concentrations as well as pyridoxal-5-phosphate (P-5-P) deficiency have been determined in 30 healthy individuals and 61 patients with coronary heart disease (CHD) verified by coronary angiography. Patients have been observed before percutaneus trans luminal coronary angioplasty followed by balloon angioplasty (10 patients; group I), 1st time stent implantation (27 patients; group II), repeated stent implantation (8 patients; group III) and due to restenosis (16 patients; group IV). An increase of serum homocysteine concentrations as well as P-5-P deficiency was observed in all groups of CHD patients, while elevated serum neopterin concentrations were identified only in CHD patients of groups III and IV i.e. mainly in patients presenting with serious coronary events. The grade of P-5-P deficiency and serum homocysteine concentrations was higher in patients with restenosis than in patients before the 1st time stent implantation, suggesting that both, normalization of P-5-P and of serum homocysteine concentrations could be significant in the prevention of CHD as well as in the treatment of CHD patients.
Suppressive Effects of Neopterin on Inducible Nitric Oxide Synthase Gene Expression in Ovarian Carcinoma Cells in vitro
Authors: Rieder Josef , Amann Anton , Schloesser Michaela , Czechowski Monika , Seibel Maja , Marth Christian , Hoffmann Georg
Published: March 2013

In a Number of malignant diseases including ovarian carcinomas, increased serum or urine levels of neopterin serve as a valuable marker for the state of activation of the cellular immune system. Reported correlations benveen elevated neopterin concentrations and shorter survival time of the tumor host might be explained by direct biochemical actions exhibited by the pteridine compound. In the present study, we investigated the influence of neopterin on inducible nitric oxide synthase (iNOS) gene expression in two ovarian carcinoma cell lines. Qualitative and quantitative analyses of iNOS as well as measurements of nitric oxide (NO) metabolites in the cell supernatant revealed an inhibitory effect of neopterin (1000 11M) on NO generation induced by a combination ofinterferon-γ (100 U/ml), tumor necrosis factor-a (500 U/ml), and interleukin-1β (10 U/ml). Since NO is most likely involved in apoptotic cell death in ovarian carcinoma cells, it is conceivable that suppression of NO synthesis represents a biochemical mechanism mediated by neopterin that is advantageous to tumor progression and thus harmful to the host.
Characterization of Pteridines: a New Approach by Fluorescence Correlation Spectroscopy and Analysis of Assay Sensitivity
Authors: Demel U. , Foldes-Papp Z. , Fuchs D. , Tilz G. P.
Published: March 2013

In the present investigation, fluorescence con-elation spectroscopy (FCS) was used to measure the molecular motion of the pteridine derivative neopterin. However, technical limitations in the present optical setup precluded the identification of ,single neopterin molecules. FCS measurements with a fluorophore were also can-ied out for comparison. Exemplified by rhodamine green, we have introduced a concept that allows the detection, identification and analysis of assays in solution at the single-molecule level in tenns of bulk concentration. This concept is based on FCS and Poisson distribution analysis of assay sensitivity. The molecules had not to be quantified in a more concentrated fonn, or in flow and trapping experiments. The study demonstrated an ultrasensitive, reliable, rapid and direct tool for analytics and diagnostics in solution. We discuss a possible application of our new concept in activation control of cell-mediated immunity via neopterin determination.
Negative Regulation of Insulin-induced Tetrahydrobiopterin Synthesis by Protein Kinase C in Vascular Endothelial Cells
Authors: Ishii Masakazu , Shimizu Shunichi , Nagai Tsutomu , Kazuhiro Shiota , Kiuchi Yuji , Yamamoto Toshinori
Published: March 2013

We examined the role ofprotein kinase C (PKC) in the insulin-induced biosynthesis oftetrahydrobiopterin (BH4)' which is one of the co factors of nitric oxide (NO) synthase (NOS), in vascular endothelial cells. The BH. level was determined as biopterin by reversed-phase high performance liquid chromatography with fluorometric detection. Measurement of the level ofrnRNA for GTP cyclohydrolase I (GTPCH), which is the fust and the rate-limiting enzyme for the novo pathway for BH4 synthesis, was performed by reverse transcription-polymerase chain reaction (RT-PCR). Treatment with insulin increased the BH4 level and the GTPCH rnRNA level in endothelial cells. The insulin-induced increases of both GTPCH rnRNA and BH4 levels were enhanced by co-treatment with bisindolylmaleimide I or Ro 31-8220, inhibitors of PKC. On the other hand, the insulin-induced increases of BH4 synthesis and expression of GTPCH rnRNA were also enhanced by co-incubation with a PKC activator, phorbol 12-myristate 13-acetate (PMA) for 24 h. Long-term treatment with PMA is known to down-regulate PKC. Addition of insulin after pretreatment with PMA for 24 h markedly enhanced BH4 synthesis and expression of .:JTPCH rnRNA. These findings suggest that PKC negatively regulates the induction of BH4 synthesis by insulin -:ndothelial cells. Insulin-induced BH4 synthesis may be suppressed in diabetes mellitus, since PKC has been shown to be up-regulated in diabetes mellitus.
Effect of Interferon-γ and LPS on Tetrahydrobiopterin in Rat PC 12 and Human KNA Cells
Authors: Vrecko Karoline , Pfragner Roswitha , Siegl Veronika , Schauenstein Konrad , Reibnegger Gilbert
Published: March 2013

The first human phaeochromocytorna cell line KNA was tested with regard to stimulation of dopamine biosynthesis by nicotinamide adenine dinucleotide (NADH). Differently from rat phaeochromocytoma cells - clone PC12, where NADH increased dopamine biosynthesis significantly, no stimulation in KNA cells was found. NADH is effective on speeding up the formation of the active cofactor tetrahydrobiopterin by a recycling pathway via the dihydropteridinreductase system. Another way of formation of tetrahydrobiopterin is the induction of de novo synthesis by cytokines such as interferon-y or by lipopolysaccharide via activation of GTP cyclohydrolase I, as shown in rnacrophages. Neither rat PC12 nor human KNA cells showed in vitro a stimulation of tetrahydrobiopterin de novo synthesis by interferon-y and/or lipopolysaccharide.
Synthesis and Regulation of Folate Coenzymes During early Germination in Vigna radiata
Authors: Kesavan V. , Singh N. , Pote M.S. , Viswanathan G.
Published: March 2013

Folate profiles and DNA synthesis were studied during the early germinating period in Vigna radiata. Total folate andmethyl folate forms were increased from 4 to 32 hours during germination period studied. Formyl folates, involved in purine synthesis, were raised 30-fold after 26 hours of incubation followed by DNA synthesis, indicatmg that folate synthesis precedes nucleotide synthesis channelising the one-carbon moieties into nucleotide precursors. This is also supported by the observation of folate mediated one-carbon pool incorporation of 2-'4C-Histidine into nucleic acid during this period. The two folate enzymes, folylpolyglutamate hydrolase which was greatly lowered and folylpolyglutamate synthetase which was significantly elevated, might playa crucial role regulating a balanced supply of the required folate precursors during the early germination period of Vigna radiata.
Supra- versus intra-molecular ππ interactions in M(S2COCH2Ph)2(dafone) compounds: M = Zn and Cd; dafone = 4,5-diazafluoren-9-one-N,N´
Authors: Câmpian Marius , Haiduc Ionel , Tiekink Edward R. T.
Published: March 2013

Remarkable differences are observed in the molecular structures of Zn(S2COCH2Ph)2(dafone) (1) and Cd(S2COCH2Ph)2(dafone) (2); where dafone is 4,5-diazafluoren-9-one-N,N′. In 1, an S,O mode of coordination of one of the xanthate ligands is observed, an orientation that facilitates the formation of intramolecular π…π interactions between the benzyl and dafone rings. The second xanthate ligand coordinates in an S,S mode and the dafone ligand is chelating. The resulting N2OS3 donor set defines a distorted octahedral coordination geometry. A similar geometry is found in 2 but based on an N2S4 donor set. Despite the different molecular structures, the global crystal packing patterns for 1 and 2 are almost identical, comprising layers.
New rare-topology [Cu4] cluster coordination polymer employing 2-(oxyimino)propionate as a ligand
Authors: Hołyńska Małgorzata
Published: March 2013

The reported compound, {Na2[Cu4(HCOO)2(pa)4(CH3OH)] · CH3OH}
n
(1, H2pa = 2-(hydroxyimino)propionic acid), is a sodium salt of an anionic coordination polymer, comprising rare-topology tetranuclear cluster units, linked through Cu–O bonds to form a polymeric chain. Each cluster unit comprises four Cu2+ cations, chelating 2-(oxyimino)propionate ligands, two formate ligands and one terminal methanol ligand. The neighbouring polymeric chains contact through O–H…O hydrogen bonds and are interconnected by Na–O coordination bonds to form a three-dimensional network.
Effect of Twin Structure on Strain Dependences of Critical Current
Authors: Semenov Alexey V. , Tretiatchenko Constantin G. , Svetchnikov Vassily L. , Pan Volodymyr M. , Wiesmann Harold
Published: March 2013

We suggest a model explaining nonlinear dependences of critical current Jc in YBCO epitaxial films. Two features of YBCO are taken into account: twin domain structure in orthorhombic phase and the anisotropy of uniaxial strain dependence of Tc. Applied strain changes elementary pinning force of the defects located at low-angle dislocation boundaries between differently oriented twin domains. Account of Tc dependence on strain this leads to approximately parabolic strain behavior of Jc. We have obtained analytical expressions for the “initial strain”, which actually describes a natural misbalance between numbers of grain boundaries separating a and b oriented domains, as well as for “strain sensitivity”, which is determined by Tc dependence on uniaxial a and b strains and by the effective redistribution of vortices. Other experimentally observed effects, such as temperature, magnetic field and two-peak strain dependences of Jc, are shown to be described in the framework of suggested model.
A Portable Setup for Molecular Detection by Transmission LSPR
Authors: Cappi Giulia , Accastelli Enrico , Spiga Fabio M. , Cantale Vera , Rampi Maria A. , Benini Luca , Guiducci Carlotta
Published: March 2013

In the framework of bioanalytics and multiple array detection, we developed a fully portable and low-cost detection system based on Localized Surface Plasmon Resonance (LSPR) in a transmission configuration (T-LSPR). The transmission approach is suitable to be scaled to small dimension systems and to enable high-density array measurements on the same platform. Our setup is made out of off-the-shelf components and consists of a set of discrete light sources and a couple of light-detectors which enable a differential measurement setup. An algorithm fits the measured data and extracts the information of the plasmon peak position in the spectrum.

The performance of our T-LSPR measurement system has been characterized on a set of Fluorinated Tin Oxide-coated glass slides covered with gold Nanoislands (NIs). The samples have been modified with a single-stranded DNA layer and a real-time DNA hybridization experiment has been performed. Here we demonstrate that the proposed T-LSPR device, based on the characterization of the plasmon peak with a differential approach, is able to monitor real-time DNA hybridization on surface, and to precisely measure the position of the peak with a standard deviation in wavelength of 0.2 nm.
Thermal Conductivity of Composites with Carbon Nanotubes: Theory and Experiment
Authors: Ordonez-Miranda J. , Vales-Pinzon C. , Alvarado-Gil J. J.
Published: March 2013

In this work, the thermal conductivity of composites made up of carbon nanotubes embedded in a polyester resin is investigated by comparing experimental data with theoretical predictions. The composite samples were prepared with a random and aligned distribution of carbon nanotubes. Its thermal conductivity is then measured by using the photothermal radiometry technique. The obtained experimental data is accurately described by the proposed theoretical model, which takes into account the size effects of the nanotubes. It is expected that the obtained results can provide useful insights on the thermal design of composites based on carbon nanotubes.
Nanoscale Heat Transport in Self-Organized Ge Clusters on Si(001)
Authors: Frigge Tim , Kalus Annika , Klasing Friedrich , Kammler Martin , Hanisch-Blicharski Anja , Horn-von Hoegen Michael
Published: March 2013

Ultrafast time resolved transmission electron diffraction (TED) in a reflection geometry was used to study the cooling behavior of self-organized, well defined nanoscale germanium hut and dome clusters on Si(001). The clusters were heated in a pump-probe scheme by fs-laser pulses. The resulting transient temperature rise was then determined from the drop in diffraction intensity caused by the Debye-Waller effect. From a cooling time of τ =177 ps we estimated a strongly reduced heat transfer compared with homogeneous films of equivalent thickness.
Investigation of the valence band structure of PbSe by optical and transport measurement
Authors: Chasapis Thomas C. , Lee Yeseul , Polymeris Georgios S. , Stefanaki Eleni C. , Hatzikraniotis Euripides , Zhou Xiaoyuan , Uher Ctirad , Paraskevopoulos Konstantinos M. , Kanatzidis Mercouri G.
Published: March 2013

We investigated the valence band structure of PbSe by a combined study of the optical and transport properties of p-type Pb1-xNaxSe, with Na concentrations ranging from 0 – 4%, yielding carrier densities in a wide range of 1018 – 1020 cm−3. Room temperature infrared reflectivity studies showed that the susceptibility (or conductivity) effective mass m* increases from ∼ 0.06mo to ∼ 0.5mo on increasing Na content from 0.08% to 3%. The Seebeck coefficient scales with doping in the whole temperature range, yielding lower values for higher Na contents, while the Hall coefficient increases on heating from room temperature showing a peak close to 650 K. The room temperature Pisarenko plot is well described by the simple parabolic band model up to ∼ 1·1020 cm−3. In order to describe the behaviour in the whole concentration range, the application of the two band model, i.e. light hole and heavy hole, was used giving density of states effective masses 0.28mo and 2.5mo for the two bands respectively.
Laser Flash Analysis Determination of the Thermal Diffusivity of Si/SiGe Superlattices
Authors: Davidson Anthony L. , Thomas James P. , Worchesky Terrance , Twigg Mark E. , Thompson Phillip E.
Published: March 2013

Applications that produce a large amount of heat, such as combustion engines, can benefit from high temperature thermoelectrics to reduce the amount of energy lost. Superlattice (SL) structures have shown reduced thermal conductivity at room temperature and below, suggesting applicability at high temperatures may be possible. This reduction could greatly increase the thermoelectric figure of merit. The Si/SiGe material system is studied here for high temperature application. Two growth temperatures of 300 C and 500 C are examined. Two superlattice periods were studied (8 nm and 20 nm) to determine the effects of lattice spacing on thermal conductivity. Laser Flash Analysis is applied to determine the thermal diffusivity, hence thermal conductivity, from 100 C to 500 C. Thermal diffusivity was found to be an order of magnitude lower than the constituent alloy at 100 C. Superlattice spacing and growth temperature showed little effect on the diffusivity within the error of this measurement.
Patterned Micro/ Nanowires by Electroplate and Lift Lithography on Reusable Ultrananocrystalline Diamond Template
Authors: Machovec Jeffrey , Lepak Lori A. , Sumant Anirudha V. , Divan Ralu , Miller C. Suzanne , Rosenmann Daniel , Zach Michael P.
Published: March 2013

Patterned micro-and nanowires composed of Iron Oxide (FexOy) were electrochemically deposited from an ionic liquid solution of choline chloride (ChCl) and urea, using ultrananocrystalline diamond (UNCD) ™ templates originally developed for Electroplate and Lift (E&L) Lithography. The wires were electroplated under varying rigor of anhydrous and inert atmosphere techniques, at voltages of either -2V or -5V vs. an Al/Al(III) reference electrode. The morphology of the deposited FexOy wires was studied by scanning electron microscopy (SEM), while their oxygen content was evaluated using energy dispersive spectroscopy (EDS). By using sublimed grade reagents and minimizing exposure to atmospheric water vapor and oxygen, the oxygen content of the electroplated wires decreased from 15 at% to 5 at%.
COMPENSATION OF THE INTERNAL STRESS GRADIENT IN ULTRANANOCRYSTALLINE DIAMOND FOR THE FABRICATION OF MICROACTUATORS AND TRIBOMETERS ON A CHIP
Authors: Buja Federico , Divan Ralu , Sumant Anirudha V. , Czaplewski David , van Spengen W. Merlijn
Published: March 2013

The excellent tribological performance of ultrananocrystalline diamond (UNCD) makes this material a potential candidate for the fabrication of long endurance micro/nano-electro-mechanical systems (MEMS/NEMS) that could involve contacting surfaces. In this work, UNCD and nitrogen incorporated UNCD (N-UNCD) microstructures have been produced and investigated, in order to analyze their intrinsic stress component. A solution for stress reduction is proposed: the application of a titanium stress-compensation coating seems to be an optimum route to obtain flat, free-standing N-UNCD films.
Attrition-enhanced nanocomposite synthesis of indium-filled, iron-substituted skutterudite antimonides for improved performance thermoelectrics
Authors: Eilertsen James , Trottmann Matthias , Populoh Sascha , Berthelot Romain , Cooke Charles M. , Cinibulk Michael K. , Pokrant Simone , Weidenkaff Anke , Subramanian M. A.
Published: March 2013

Nanostructuring has been the foremost approach to the manufacture of high-performance thermoelectric materials for nearly a decade. This study explores a novel nanostructuring technique, attrition-enhanced nanocomposite synthesis, in maximum indium-filled, iron-substituted cobalt antimonide skutterudites. In0.3Fe0.8Co3.2Sb12 was synthesized and subjected to varying degrees of mechanical attrition (via ball milling). These samples exhibited increased indium precipitation coincident with the duration of mechanical attrition. Indium readily diffused through the skutterudite crystal structure and rapidly precipitated forming 20-50 nm-sized indium-rich inclusions during sintering.
Análise de trilha para carotenoides em milho
Authors: Rios Sara de Almeida , Borém Aluízio , Guimarães Paulo Evaristo de Oliveira , Paes Maria Cristina Dias
Published: March 2013

Ainda que sejam considerados os aspectos de magnitude e significância, o estudo de correlações entre caracteres por si só não garante causa e efeito entre eles. Dessa forma, o objetivo deste trabalho foi desdobrar as correlações fenotípicas em seus efeitos diretos e indiretos, pela análise de trilha, considerando o perfil de carotenoides em genótipos de milho. Foram utilizados dados obtidos do ensaio nacional de cultivares de milho conduzido pela Embrapa Milho e Sorgo, no ano agrícola 2004/2005, com média de 10 genótipos em cinco ambientes. Avaliaram-se os teores de carotenoides totais (CT), α e β-carotenos, luteína, zeaxantina e β-criptoxantina. A xantofila zeaxantina apresenta o maior efeito direto sobre β-caroteno. As altas correlações entre β-caroteno e carotenoides totais e entre β-caroteno e β-criptoxantina são devidas ao efeito indireto, via zeaxantina. A seleção direta de genótipos com altos teores de β-caroteno apresenta-se como a alternativa de maior efetividade, mas se outras frações de carotenoides também forem consideradas, esquemas de seleção simultânea de caracteres, por meio da utilização de índices de seleção, mostram-se mais eficientes na obtenção de genótipos com altos teores de β-caroteno do que a resposta correlacionada.
Variation in adult body mass of roe deer: early environmental conditions influence early and late body growth of females
Authors: Douhard Mathieu , Gaillard Jean-Michel , Delorme Daniel , Capron Gilles , Duncan Patrick , Klein François , Bonenfant Christophe
Published: March 2013

There is increasing evidence that environmental conditions experienced early in life can markedly affect an organism's life history, but the pathways by which early environment influences adult phenotype are poorly known. We used long‐term data from two roe deer (Capreolus capreolus) populations (Chizé and Trois‐Fontaines, France) to investigate the direct and indirect (operating through fawn body mass) effects of environmental conditions during early life on adult body mass. We found that environmental conditions (population size and spring temperatures) around birth influenced body mass of adult females through both direct and indirect effects in both populations. The occurrence of direct effects means that, for a given fawn body mass, adult female mass decreases with adverse conditions in early life. In contrast, we found no evidence for direct effects of early‐life conditions on adult body mass of males, suggesting the existence of sex‐specific long‐term responses of body mass to stressful early conditions. Our results provide evidence that early environmental conditions influence the adult phenotype through persistent effects over the body development in wild mammal populations.
The moral status of contraception and openness to procreation
Authors: Prijic-Samarzija Snjezana
Published: March 2013

Permissibility of contraception as a method of birth control is closely
connected with issues of moral justification of reproductive autonomy, namely
the question whether or not individuals should be allowed to autonomously and
freely decide if they are going to have children, when and how many. The
development of medical and scientific technologies led to the usage of
artificial methods of contraception that can prevent concep?tion with the
goal of postponing and planning the birth of a child. In the first part I
analyze the bioethical arguments that appear in debates about reproductive
autonomy and which can be mobilized against the permissibility of
contraception. In the second part I have compared the bioethical arguments
to those used against the artificial contraception in the literature about
the philosophy of sexuality. In the third and final part, I have argued
against the stance of G.E.M. Anscombe and J. Finnis that there is morally
relevant distinction be?tween artificial and natural methods of birth
control.
On feminist engagements with bioethics
Authors: Drezgic Rada
Published: March 2013

The article explores two questions: what is feminist bioethics, and how
different it is from standard bioethics. Development of feminist bioethics,
it is argued, began as a response to standard bioethics, challenging its
background values, and philosophical perspectives. The most important
contribution of feminist bioethics has been its re-examination of the basic
conceptual underpinnings of mainstream bioethics, including the concepts of
?universality?, ?autonomy?, and ?trust?. Particularly important for feminists
has been the concept of autonomy. They challenge the old liberal notion of
autonomy that treats individuals as separate social units and argue that
autonomy is established through relations. Relational autonomy assumes that
identities and values are developed through relationships with others and
that the choices one makes are shaped by specific social and historical
contexts. Neither relational autonomy, nor feminist bioethics, however,
represents a single, unified perspective. There are, actually, as many
feminist bioethics as there are feminisms-liberal, cultural, radical,
postmodern etc. Their different ontological, epistemological and political
underpinnings shape their respective approaches to bioethical issues at hand.
Still what they all have in common is interest in social justice-feminists
explore mainstream bioethics and reproductive technologies in order to
establish whether they support or impede gender and overall social justice
and equality. Feminist bioethics thus brings a significant improvement to
standard bioethics.
Serbian bioethics from an international perspective: Genetics and bioethics
Authors: Marinkovic Dragoslav , Magic Zvonko
Published: March 2013

Global interests in bioethics have increased drastically since the end of
20th century. The reason for this should be ascribed to a broad application
of molecular-genetic methods introduced in human bio-medicine. This has, in
turn, produced an involvement and development of numerous inter-disciplines,
which have started to apply bioethics as a part of their own subject of
interest. This article presents more than a decade of experience of teaching
bioethics in our country, particularly under the auspices of the National
Com?mittee for Bioethics of UNESCO-commission of Serbia.
Sajmiste as a European site of Holocaust remembrance
Authors: Browning Christopher
Published: March 2013

The article analyzes the peculiarities of the destruction of Serbian Jews
during Second Wolrd War in the local and European context. Of all the sites
in Serbia relevant to the destruction of the Serbian Jews, Sajmiste is the
most important. After the consideration of the attitude of Germans and
Nedic?s regime toward Jews and ?Gypsies? in the context of the Final
Solution, the author highlights that the Sajmiste internment camp was
transformed into a local death camp-the only such site outside the
territories of Poland and the Soviet Union. Serbia was the one country
outside Poland and the Soviet Union where all Jewish victims were killed on
the spot without deportation. It was the first country after Estonia to be
declared ?judenfrei.? Moreover, in Serbia the German army was not only
complicit in the Holocaust but was in fact the main instigator and
executioner in the killing of the Jewish men. For this reason, in particular,
Sajmiste is a unique site for Holocaust remembrance not only in the Serbian
but also in the European context.
Germany’s memorial to the murdered Jews of Europe: Debates and reactions
Authors: Neumärker Uwe
Published: March 2013

The article outlines the history of the Memorial to the Murdered Jews of
Europe in Berlin as a very good example of how long any such procedure is,
from idea to realization, as well as how strong the debate how and whom to
commemorate. Federal Foundation Memorial to the Murdered Jews of Europe also
supervised Memorial to the Murdered Sinti and Roma, Memorial to the
Homosexuals Persecuted under the National Socialist Regime and the Memorial
to mass murder of patients from mental hospitals. Besides that, the author
analyzes the initiatives and sollutions for other monuments in Germany?s
capital New Guard Room, as well as the Concentration Camp Sachsenhausen near
Berlin.
Integrating agonism with deliberation: Realising the benefits
Authors: Knops Andrew
Published: March 2013

In ?Agonism as Deliberation? (Knops 2007) I suggest a reconciliation between
Mouffe?s agonist version of democracy, adjusted to preserve consistency, and
deliberation. Here I reply to two subsequent criticisms of this project:
G?rs?zl? (2009) and Fives (2009). Although both hold agonism and deliberation
incompatible impossible, they do so from opposing perspectives. G?rs?zl?
defends Mouffe?s agonism as distinct and coherent on the basis of what he
considers a correct understanding of her concept of hegemony. Fives argues
Mouffe?s approach is separate but incoherent, and should be rejected. Against
these two conflicting positions, I seek to demonstrate not only that
integration between agonism and democracy is possible, but that it has
distinct benefits for both agonism and deliberative theory. Divested of its
contradictory assertion that universal rational consensus is impossible in
principle, agonism can be interpreted as theory of the moment of difference
within a broader deliberative dialectic that seeks to move from more to less
partial consensus. Conceived in this way, we can better appreciate how these
two approaches can complement one another, in pursuing shared goals, rather
than the static and unnecessary opposition offered by the two critics I
address here.
Integration of deliberative democracy and policy-making: A vision of a deliberative system
Authors: Savic Vanja
Published: March 2013

The paper examines major propositions of deliberative democratic theory,
divided into problems of inclusion, deliberation and citizenship and their
parallel articulation, as well as empirical examination and specification, in
literature on post-empiricist policy-making. The theory of deliberative
democracy and literature on deliberative policy-making have raised similar
concerns and made parallel proposals about possible remedies of ills of
contemporary democracy i.e. policy-making, specifically concerning broader
inclusion in democratic and policy-making practices, deliberative
consideration of issues in both policy-making and democratic politics and
enhanced civic skills of democratic participants i.e. policy-takers. Authors
in both sets of literature reach a similar conclusion about incorpora?tion of
democratic i.e. policy-making deliberative efforts into institutions of
liberal democracy so as to create a larger ?deliberative system? of
interconnected chains of communication and legitimacy.
Reparations for U.S. war crimes against Iraq
Authors: Corlett Angelo
Published: March 2013

Given the basic tenets of just war theory and those of United States law
regarding compensatory justice, it is argued that the U.S. invasion of Iraq
from 2003-present is morally unjust and that the U.S. owes substantial
reparations to Iraq.
Cultural aspects of the current Scandinavian identity crisis: The case of Denmark-purity under attack
Authors: Møller Tine
Published: March 2013

In this article I will attempt to show examples of the cultural
manifestations of the identity crisis that is currently sweeping over
Scandinavia. What is particular about this crisis is that it seems to have
struck on most sides of society, while the ?Scandinavian model? of the
welfare state is slowly crumbling in the wake of the global financial
problems. At the center of both this struggle and crisis is the notion of the
Homo Scandinavicus; this seems at the same time a threat to existence (by
different enemies, depending on one?s stand in the struggle) and contested in
its very content. In all Scandinavian countries a so-called ?cultural battle?
has been articulated and used as heavy artillery when articulating
characteristics of either side. It is this battle I will highlight and
demonstrate through examples how the ?general public? has been taken hostage
on this identity battle field. Furthermore, I will give examples of
alternative strategies (notably found in the art worlds), and why these have
also failed to provide actual functioning alternatives to the leading,
rivaling, identity strategies. The nature of this crisis and the ways it
manifests itself, are by no means strictly restricted to Scandinavia.
Therefore, considerations about manifestations and consequences presents some
highly relevant and much more general insights.
Phänomenologisch-kritische Destruktion des Aprioriproblems beim frühen Heidegger
Authors: Radinkovic Zeljko
Published: March 2013

Der Beitrag pr?ft zun?chst, inwiefern beim fr?hen Heidegger (vor
Sein und Zeit) eine Verschiebung des Schwerpunktes von dem umweltlichen
Charakter der Erlebnisse auf das ?faktisch? daseiende Leben bzw. auf das
Ph?nomen ?Ich bin? zu beobachten ist. Es gilt, den Seinssinn vom ?Ich bin? zu
fassen und zwar, indem der Unterschied der Selbsterfahrung zum
reflexiv-theoretischen Einstellung bestimmt wird. Diese Bestimmung soll von
allen Regions - und Sachgebietsfremdheiten ferngehalten werden. Die
Individuation des ?Ich bin? soll nicht als Vereinzelung im Hinblick auf das
Allgemeine, sondern als das historische Vereinzelung gefasst werden. Der
Seinssinn als Existenzsinn ist in der Eigener?fahrung zu fassen und hat einen
Vollzugscharakter. Die Grunderfahrung des Selbst bzw. die Geschichtlichkeit
des Vollzuugscharakters des Selbst werden in ein neues grundlegendes
Verh?ltnis zu Apriorit?t gesetzt. Die zentrale Rolle kommt dabei der
Destruktion des historischen Horizontes des Aprioriproblems, worunter eine
Radikalisierung der Ph?nomenologie zu verstehen ist, die versucht, die eigene
Geschichtlichkeit bzw. geschichtliche Situation immer urspr?nglicher zu
vollziehen. Es wird die inhaltliche Struktur des Aprioriproblems gekl?rt,
indem die Geschichte des Aprioriauffassungen nach dem Grad ihrer
Daseinsim-manenz bestimmt werden. Die Destruktion des Aprioriproblems wird an
den rekonstruktiven Psychologie Paul Natorps und der Kritik der historischen
Vernunft Wilhelm Diltheys versucht, wobei diesen die Verdinglichung der
Sph?re des Lebendigen vorgeworfen wird.
Pseudorandom position encoder with improved zero position adjustment
Authors: Denic Dragan , Miljkovic Goran , Lukic Jelena , Arsic Miodrag
Published: March 2013

Pseudorandom position encoder, which employs two code tracks for absolute
position measurement, represents one of the latest trends in the development
of the absolute position encoders. One sensor head is used for pseudorandom
code reading and two additional sensor heads are used for generating
synchronization pulses and motion direction determination. Special attention
is devoted to the zero position adjustment after the installation of the
encoder on the motor shaft. A novel solution for the improved zero position
adjustment incorporated in the functional algorithm of the encoder is
presented in this paper. The presented solution offers a reliable procedure
for the zero position adjustment, taking into account possible motion
direction changes during the zero position adjustment process. The algorithm
for the zero position adjustment executes only once and does not participate
further in the absolute position measurement process. The functioning of the
proposed algorithm is described in more details considering one concrete
example of the encoder.
Multiband sensors for wireless electromagnetic field monitoring system - SEMONT
Authors: Milutinov Miodrag , Djuric Nikola , Pekaric-Nadj Neda , Miskovic Dragisa , Knezevic Dragan
Published: March 2013

Substantial effort has been made to employ wireless sensor network and
Internet technologies for environmental and habitat protection. Several
monitoring systems are designed to collect data regarding temperature,
humidity, pressure and some other environmental parameters, amongst which
recently there is the exposure to electromagnetic field. In this paper, some
basic features of the multiband sensors that are incorporated into the
Serbian electromagnetic field monitoring network - SEMONT are presented. The
SEMONT information network is designed and aimed for the remote, long-term,
24 hours a day, permanent broadband monitoring of the electromagnetic field
in the environment.
Linearization of symmetrical and asymmetrical two-way Doherty amplifier
Authors: Atanaskovic Aleksandar , Males-Ilic Natasa , Milovanovic Bratislav
Published: March 2013

The linearization effects on two-way Doherty amplifiers are presented in this
paper. Symmetrical Doherty amplifier with the additional circuit for
linearization has been realized and measurements of the linearization
influence on the third- and fifth-order intermodulation products have been
carried out. Asymmetrical Doherty amplifier has been designed and effects of
the applied linearization technique have been considered through the
simulation process. The linearization approach uses the fundamental signals?
second harmonics and fourth-order nonlinear signals that are extracted at the
output of the peaking cell, adjusted in amplitude and phase and injected at
the input and output of the carrier cell in Doherty amplifier.
Software solution for control and data acquisition in the pulse calorimetry method
Authors: Babic Marijana , Milosevic Nenad , Stepanic Nenad
Published: March 2013

This work presents a software solution for adjusting, controlling,
displaying, and acquiring parameters and data in the pulse calorimetry
experimental technique for specific heat capacity, electrical resistivity,
total hemispherical emissivity, and normal spectral emissivity measurements.
The software has been developed under the LabVIEW platform, V.7.11, and an
example of its application with measurement results is presented in a
separate section. The total expanded uncertainty of obtained results for the
specific heat capacity and electrical resistivity of palladium was 5% and 1 -
2%, respectively.