129 research outputs found
Little-Parks effect in single YBaCuO sub-micron rings
The properties of single submicron high-temperature superconductor (HTS)
rings are investigated. The Little-Parks effect is observed and is accompanied
by an anomalous behavior of the magnetic dependence of the resistance, which we
ascribe to non-uniform vorticity (superfluid angular momentum) within the ring
arms. This effect is linked to the peculiar HTS-relationship between the values
of the coherence length and the London penetration depth.Comment: 14 pages, 3 figure
THz characterization of a metamaterial-based Spatial Light Modulator
The aim of this work is to investigate new classes of artificial materials exhibiting unconventional properties in order to build novel devices operating in the Terahertz regime. We focus on the design, fabrication and characterization of tunable metamaterials with unit cells based on Split Ring Resonators. By incorporation of a nematic liquid crystal in the structure, we observe a frequency shift in the resonant response over 10% in bandwidth and more than 10 dB change in the signal absorption. We discuss how such a hybrid structure can be exploited for the development of a THz spatial light modulator
Effective EMI shielding behaviour of thin graphene/PMMA nanolaminates in the THz range
The use of graphene in a form of discontinuous flakes in polymer composites limits the full exploitation of the unique properties of graphene, thus requiring high filler loadings for achieving- for example- satisfactory electrical and mechanical properties. Herein centimetre-scale CVD graphene/polymer nanolaminates have been produced by using an iterative ‘lift-off/float-on’ process and have been found to outperform, for the same graphene content, state-of-the-art flake-based graphene polymer composites in terms of mechanical reinforcement and electrical properties. Most importantly these thin laminate materials show a high electromagnetic interference (EMI) shielding effectiveness, reaching 60 dB for a small thickness of 33 μm, and an absolute EMI shielding effectiveness close to 3·105 dB cm2 g−1 which is amongst the highest values for synthetic, non-metallic materials produced to date
Investigation of primary microcephaly in Bushehr province of Iran: novel STIL and ASPM mutations
Geometrical vortex lattice pinning and melting in YBaCuO submicron bridges
Since the discovery of high-temperature superconductors (HTSs), most efforts of researchers have
been focused on the fabrication of superconducting devices capable of immobilizing vortices,
hence of operating at enhanced temperatures and magnetic fields. Recent findings that geometric
restrictions may induce self-arresting hypervortices recovering the dissipation-free state at high fields
and temperatures made superconducting strips a mainstream of superconductivity studies. Here we
report on the geometrical melting of the vortex lattice in a wide YBCO submicron bridge preceded by
magnetoresistance (MR) oscillations fingerprinting the underlying regular vortex structure. Combined
magnetoresistance measurements and numerical simulations unambiguously relate the resistance
oscillations to the penetration of vortex rows with intermediate geometrical pinning and uncover the
details of geometrical melting. Our findings offer a reliable and reproducible pathway for controlling
vortices in geometrically restricted nanodevices and introduce a novel technique of geometrical
spectroscopy, inferring detailed information of the structure of the vortex system through a combined
use of MR curves and large-scale simulations
Tensor voting for robust color edge detection
The final publication is available at Springer via http://dx.doi.org/10.1007/978-94-007-7584-8_9This chapter proposes two robust color edge detection methods based on tensor voting. The first method is a direct adaptation of the classical tensor voting to color images where tensors are initialized with either the gradient or the local color structure tensor. The second method is based on an extension of tensor voting in which the encoding and voting processes are specifically tailored to robust edge detection in color images. In this case, three tensors are used to encode local CIELAB color channels and edginess, while the voting process propagates both color and edginess by applying perception-based rules. Unlike the classical tensor voting, the second method considers the context in the voting process. Recall, discriminability, precision, false alarm rejection and robustness measurements with respect to three different ground-truths have been used to compare the proposed methods with the state-of-the-art. Experimental results show that the proposed methods are competitive, especially in robustness. Moreover, these experiments evidence the difficulty of proposing an edge detector with a perfect performance with respect to all features and fields of application.This research has been supported by the Swedish Research Council
under the project VR 2012-3512
A novel point mutation in P450c17 (CYP17) causing combined 17 alpha-hydroxylase/17,20-lyase deficiency
Context: Combined 17 alpha-hydroxylase/17,20-lyase deficiency is a rare cause of congenital adrenal hyperplasia and hypogonadism. Novel single amino acid changes in P450c17 provide potentially important insights into key structural domains for enzyme function.Objective, Design, and Setting: We report a novel missense mutation in P450c17 in a 17-yr-old female presenting with a malignant mixed germ cell tumor with yolk sac elements who demonstrated clinical and biochemical features of combined 17 alpha-hydroxylase/17,20-lyase deficiency.Methods: Quantitative urinary steroid analysis was performed by high resolution gas chromatography. All eight coding exons of CYP17 were PCR amplified and sequenced. The position of arginine at codon 96 was modeled using the CYP17 structure 2c17 (www.rcsb.org). The CYP17 genes were subcloned into pcDNA3, expressed in HEK-293 cells, and chromatographed.Patient and Results: 17 beta-Hydroxylase deficiency was confirmed by marked reductions in urinary and serum cortisol, androgens, and estradiol. Mutational analysis revealed a novel homozygous R96Q missense mutation in P450c17, affecting an amino acid in a key substrate-binding region of the enzyme, leading to complete inactivity.Conclusion: The description of a second missense mutation at codon 96 (R96W and R96Q) in the substrate-binding region of P450c17 provides strong evidence for the key role of this amino acid in 17 alpha-hydroxylase/17,20-lyase function. An association between a malignant germ cell tumor and 17 alpha-hydroxylase deficiency has not been reported previously, although the presence of gonadoblastoma in the ovary of a patient with this condition has recently been described
Efficiency of shrimp trawl nets polyamide and polyethylene with standard mesh in the coastal waters of Bushehr Province
This study was carried out in August – september 2009 in Bushehr province waters. Two different shrimp bottom trawls were used in which were woven by Poly Amid and Poly Ethylene with mesh sizes (stretched) of 50 mm and sack with 35 mm. Also 2 different vessels of two dhows and one steel ship each with 26 and 30 hauls were used and taken in to comparison from point of obtained results. Total catch of PA and PE trawels were 4592 and 5535 kg of which the ratio of shrimp catch and by catch for PA trawl was 32.4 and 67.6 % respectively; and for PE trawl was 34.2 and 65.8%. Total catch of PA and PE trawls of steel trawler ( ship ) were estimated 3158.0 and 4784.7 kg, respectively, of which the shrimp/ bycatch ratio was 6.6 : 93.4%. There was a higher amount of bycatch for PE comparing to PA trawl (p<0.05). on the other hand the decrease of shrimp and bycatch for PA comparing to PE dhow trawlers were 21.3 and 15.0% and for ship were 34.6 and 34.0% respectively. The weight ratio is 1:15 i.e . in PE ship trawl, in proportion to on kg shrimp, 15 kg bycatch was harvested. it is proposed to standardize the mesh size and also to do obligtory the instal of squared mesh size panel
Genetics of intellectual disability in consanguineous families
Autosomal recessive (AR) gene defects are the leading genetic cause of intellectual disability (ID) in countries with frequent parental consanguinity, which account for about 1/7th of the world population. Yet, compared to autosomal dominant de novo mutations, which are the predominant cause of ID in Western countries, the identification of AR-ID genes has lagged behind. Here, we report on whole exome and whole genome sequencing in 404 consanguineous predominantly Iranian families with two or more affected offspring. In 219 of these, we found likely causative variants, involving 77 known and 77 novel AR-ID (candidate) genes, 21 X-linked genes, as well as 9 genes previously implicated in diseases other than ID. This study, the largest of its kind published to date, illustrates that high-throughput DNA sequencing in consanguineous families is a superior strategy for elucidating the thousands of hitherto unknown gene defects underlying AR-ID, and it sheds light on their prevalence
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