326 research outputs found

    Geochemistry and Petrogenesis of metabasites from the Gol-e-Gohar Complex in southern Sanandaj-Sirjan metamorphic zone, South of Iran; Evidences for crustal extension and magmatism at early Palaeozoic

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    In Gol-e-Gohar metamorphic Complex from south-eastern Sanandaj-Sirjan metamorphic zone (Kerman province, Iran), there are two types of metabasites contain layered metamorphosed lava flows and the younger meta-gabbros. The protoliths formed in the Paleozoic era and were metamorphosed during the early Cimmerian orogenic phase in the late Triassic, under temperatures of 640–680ºC and pressures of ~7–10.5kbar (amphibolite facies). These rocks are garnet-bearing amphibolites, garnet free amphibolites and metamorphosed gabbros. Many mineralogical and chemical aspects of these metabasites are similar, although the layered metabasites show tholeiitic and the meta-gabbros depict alkaline affinities. Evidences such as whole rock geochemical characteristics, Sr and Nd isotopic data, (143Nd/144Ndinitial=0.511913–0.512067; εNd550Ma=-0.31–2.68), relatively flat patterns of chondritenormalized Rare Earth Elements and multi-elemental diagrams, the enrichment in TiO2 (average content ~2.16) and high Zr/Y ratios (3–8), indicate that all of Gol-e-Gohar metabasites are formed in an extentional intracontinental rift zone from tholeiitic to alkaline magmas. The data suggest that the paren magmas could derived by low degrees of partial melting of spinel-lherzolite sources in subcontinental lithospheric mantle. These evidences confirm the existence of extentional environments in southern part of the Sanandaj-Sirjan metamorphic zone in the Paleozoic era, when large extensional depressions developed in the Sanandaj-Sirjan metamorphic zone and underlying asthenosphere ascent and partially melted during this time. Gradually, thick sequences of continental detritic sediments and tholeiitic lava flows accumulated in these troughs. Subsequent magmatic event in the area characterizes by emplacement of alkaline gabbro intrusions. At the early Cimmerian orogeny, these sedimentaryigneous rocks associations metamorphosed and the Gol-e Gohar metabasites formed

    Modification of 10 cGy neutron or gamma-rays induced chromosomal damages by hyperthermia: an in vitro study

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    Background: To evaluate the effects of hyperthermia (HT) on the frequency of chromosomal aberrations induced by a low dose of neutron or Y-rays in human peripheral blood lymphocytes. Materials and Methods: Blood samples were exposed to HT (41.5 degrees C for 30 and 60min, 43 degrees C for 15 and 30min), 10 cGy neutron or Y-rays, HT + neutron/Y, and neutron/Y + HT. After standard cell culture, harvesting, fixation and staining, the chromosomal damages were scored in metaphase plates. Results: HT alone at 41.5 degrees C did not induce chromatid or chromosome aberrations, however, the frequency of damages was significantly higher at 43 C (P<0.05). Furthermore, the chromosomal damages was significantly different when cells were irradiated with neutron or Y-rays alone (P<0.01). HT 1 hr post neutron/Y irradiation significantly induced higher chromosome damages in comparison to HT 1 hr before irradiation (P<0.05). The chromosomal damages were remarkably higher when cells were irradiated with neutron then heated at 43 C for 30 min. Conclusion: Since increasing frequency of chromosome damages increases probability of cell death, application of HT after neutron irradiation (instead of X- or gamma- rays) might be considered as a procedure for cells killing in radiotherapy. Iran. J. Radiat. Res., 2009; 7 (2): 69-7

    Accelerated design of architectured ceramics with tunable thermal resistance via a hybrid machine learning and finite element approach

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    Abstract Topologically interlocked architectures can transform brittle ceramics into tougher materials, while making the material design procedure a cumbersome task since modeling the whole architectural design space is not efficient and, to a degree, is not viable. We propose an approach to design architectured ceramics using machine learning (ML), trained by finite element analysis data and together with a self-learning algorithm, to discover high-performance architectured ceramics in thermomechanical environments. First, topologically interlocked panels are parametrically generated. Then, a limited number of designed architectured ceramics subjected to a thermal load is studied. Finally, the multilinear perceptron is employed to train the ML model in order to predict the thermomechanical performance of architectured panels with varied interlocking angles and number of blocks. The developed feed-forward artificial neural network framework can boost the architectured ceramic design efficiency and open up new avenues for controllability of the functionality for various high-temperature applications. This study demonstrates that the architectured ceramic panels with the ML-assisted engineered patterns show improvement up to 30% in frictional energy dissipation and 7% in the sliding distance of the tiles and 80% reduction in the strain energy, leading to a higher safety factor and the structural failure delay compared to the plain ceramics

    Effects of cell phone waves on granular cells migration of cerebellum in neonatal rat

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    زمینه و هدف: استفاده روز افزون از تلفن های همراه باعث افزایش نگرانی ها در مورد آثار بیولوژیک امواج این دستگاه بر بافت های بدن، بخصوص سیستم عصبی مرکزی شده است. این مطالعه با هدف بررسی اثر امواج تلفن همراه بر مهاجرت سلول‌های گرانولار مخچه در رت انجام شده است. روش بررسی: در این مطالعه تجربی 40 سر نوزاد رت به طور تصادفی به 4 گروه ده تایی تقسیم شدند. یک گروه شاهد و سه گروه آزمایشی I، II و III که در روزهای 7 تا 13 بعد از تولدشان روزانه بترتیب 5/0، 2 و 8 ساعت از فاصله cm10 مورد تابش امواج تلفن همراه قرار ‌گرفتند. در روز چهاردهم، پس از کشتن رت ها و تهیه مقاطع بافتی، با استفاده از نرم‌افزار موتیک سلول های گرانولار مخچه شمارش شدند؛ همچنین ضخامت لایه گرانولار با نرم‌افزار Nikon اندازه‌گیری شد. یافته‌ها: جمعیت سلولی ناحیه گرانولار داخلی مخچه در گروه آزمایشی III نسبت به گروه شاهد، به طور معنی ‌داری کاهش یافت (05/0

    Polymer Translocation Dynamics in the Quasi-Static Limit

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    Monte Carlo (MC) simulations are used to study the dynamics of polymer translocation through a nanopore in the limit where the translocation rate is sufficiently slow that the polymer maintains a state of conformational quasi-equilibrium. The system is modeled as a flexible hard-sphere chain that translocates through a cylindrical hole in a hard flat wall. In some calculations, the nanopore is connected at one end to a spherical cavity. Translocation times are measured directly using MC dynamics simulations. For sufficiently narrow pores, translocation is sufficiently slow that the mean translocation time scales with polymer length N according to \propto (N-N_p)^2, where N_p is the average number of monomers in the nanopore; this scaling is an indication of a quasi-static regime in which polymer-nanopore friction dominates. We use a multiple-histogram method to calculate the variation of the free energy with Q, a coordinate used to quantify the degree of translocation. The free energy functions are used with the Fokker-Planck formalism to calculate translocation time distributions in the quasi-static regime. These calculations also require a friction coefficient, characterized by a quantity N_{eff}, the effective number of monomers whose dynamics are affected by the confinement of the nanopore. This was determined by fixing the mean of the theoretical distribution to that of the distribution obtained from MC dynamics simulations. The theoretical distributions are in excellent quantitative agreement with the distributions obtained directly by the MC dynamics simulations for physically meaningful values of N_{eff}. The free energy functions for narrow-pore systems exhibit oscillations with an amplitude that is sensitive to the nanopore length. Generally, larger oscillation amplitudes correspond to longer translocation times.Comment: 13 pages, 13 figure

    Geochemistry and petrogenesis of metabasites from the Gol-e-Gohar Complex in southern Sanandaj-Sirjan metamorphic zone, South of Iran; Evidences for crustal extension and magmatism at early Palaeozoic

    Get PDF
    In Gol-e-Gohar metamorphic Complex from south-eastern Sanandaj-Sirjan metamorphic zone (Kerman province, Iran), there are two types of metabasites, wich contain layered metamorphosed lava flows and younger meta-gabbros. The protoliths formed in the Paleozoic era and were metamorphosed during the early Cimmerian orogenic phase in the late Triassic, under temperatures of 640-680ºC and pressures of ~7-10.5kbar (amphibolite facies). These rocks are garnet-bearing amphibolites, garnet-free amphibolites and metamorphosed gabbros. Many mineralogical and chemical aspects of these metabasites are similar, although the layered metabasites show tholeiitic and the metagabbros depict alkaline affinities. Evidences such as whole rock geochemical characteristics, Sr and Nd isotopic data, (143Nd/144Ndinitial=0.511913-0.512067; εNd550Ma=-0.31-2.68), relatively flat patterns of chondrite-normalized Rare Earth Elements and multi-elemental diagrams, the enrichment in TiO2 (average content ~2.16) and high Zr/Y ratios (3-8), indicate that all of Gol-e-Gohar metabasites were formed in an extensional intra-continental rift zone from tholeiitic to alkaline magmas. The data suggest that the parent magmas could derive from low degrees of partial melting of spinel-lherzolite sources in subcontinental lithospheric mantle. These evidences confirm the existence of extensional environments in the southern part of the Sanandaj-Sirjan metamorphic zone in the Paleozoic era, when large extensional depressions developed in the Sanandaj-Sirjan metamorphic zone with underlying asthenosphere ascent. Partial melting took place during this time. Gradually, thick sequences of continental detritic sediments and tholeiitic lava flows accumulated in these troughs. A subsequent magmatic event in the area was characterized by emplacement of alkaline gabbro intrusions. At the early Cimmerian orogeny, these sedimentary-igneous rock associations metamorphosed and the Gol-e-Gohar metabasites formed

    TRANSFER LEARNING METHOD FOR SLEEP STAGES CLASSIFICATION USING DIFFERENT DOMAIN

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    Sleep stages classification using the signal analysis includes electroencephalogram (EEG), Electrooculography (EOG), Electromyography (EMG), Photoplethysmogram (PPG), and electrocardiogram (ECG). In this study, the proposed method using transfer learning to sleep stages classification. First, we have used the PPG and ECG signals, because they are less complex. This signal has the least complexity, and in this article we used this signal for transitional learning. n this study, we extracted 52 features from two signals and prepared for the classification stage. This method includes two steps, (a) Train data PPG and Test data ECG, (b) Train data ECG and Test data PPG. Results proved that our method has acceptable reliability for classification. The accuracy of 95.25% and 94.63% has been reached

    Description of combined ARHSP/JALS phenotype in some patients with SPG11 mutations

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    Background: SPG11 mutations can cause autosomal recessive hereditary spastic paraplegia (ARHSP) and juvenile amyotrophic lateral sclerosis (JALS). Because these diseases share some clinical presentations and both can be caused by SPG11 mutations, it was considered that definitive diagnosis may not be straight forward. Methods: The DNAs of referred ARHSP and JALS patients were exome sequenced. Clinical data of patients with SPG11 mutations were gathered by interviews and neurological examinations including electrodiagnosis (EDX) and magnetic resonance imaging (MRI). Results: Eight probands with SPG11 mutations were identified. Two mutations are novel. Among seven Iranian probands, six carried the p.Glu1026Argfs*4-causing mutation. All eight patients had features known to be present in both ARHSP and JALS. Additionally and surprisingly, presence of both thin corpus callosum (TCC) on MRI and motor neuronopathy were also observed in seven patients. These presentations are, respectively, key suggestive features of ARHSP and JALS. Conclusion: We suggest that rather than ARHSP or JALS, combined ARHSP/JALS is the appropriate description of seven patients studied. Criteria for ARHSP, JALS, and combined ARHSP/JALS designations among patients with SPG11 mutations are suggested. The importance of performing both EDX and MRI is emphasized. Initial screening for p.Glu1026Argfs*4 may facilitate SPG11 screenings in Iranian patients. © 2020 The Authors. Molecular Genetics & Genomic Medicine published by Wiley Periodicals LL
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