229 research outputs found

    Modeling the effects of high strain rate loading on RC columns using Arbitrary Lagrangian Eulerian (ALE) technique

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    In recent years, many studies have been conducted by governmental and nongovernmental organizations across the world in an attempt to better understand the effect of explosive loads on buildings in order to better design against specific threats. This study is intended to contribute to increase the knowledge about how explosions affect reinforced concrete (RC) columns. In this study, a nonlinear model is developed to study the blast response of RC columns subjected to explosive loads. Numerical modeling of RC column under explosive load is presented using advanced finite element code LS DYNA. The obtained numerical model is validated with the experimental test and the results are in substantial agreement with the experimental data. ALE method for blast analysis is presented in the current research. The effects of scaled distance on the damage profile of RC columns are investigated. The results demonstrate that the level of damage increased with describing the scaled distance. Also the results shown duration for the blast loading, and hence the impulse, varies with charge masses at the specified scaled distance. Higher magnitude charge masses produced longer blast loading durations than lower magnitude charge masses. This means that at the same scaled distance, a charge mass of higher magnitude produced a higher impulse than the lower magnitude charge mass. The findings of this research represent the scaled distance is an important parameter that should be taken into account when analyzing the behavior of RC columns under explosive effects. The data collected from this research are being used to improve the knowledge of how structures will respond to a blast event, and improve finite element models for predicting the blast performance of concrete structures.Peer Reviewe

    Langerhans cells in odontogenic cysts. A retrospective study based on 142 cases

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    Dendritic cells with the ultrastructural and immunocytochemical characteristics of Langerhans cells are commonly identified in lymphoid organs and in keratinized and non-keratinized epithelia, such as oral mucosa. These types of cells were previously described in the epithelial wall of periapical odontogenic cysts.S-100 protein positive cells were demonstrated immunocytochemically in all of our 142 cases of odontogenic cysts (32 developmental cysts; 110 inflammatory cysts). Their tropism for squamous epithelia may explain their presence in the epithelial wall of odontogenic cysts. Their number is not always correlated with an inflammatory condition.Des cellules dendritiques présentent les caractéristiques immunocytochimiques et ultrastructurales des cellules de Langerhans sont communément observées dans les épithélium kératinisés et non kératinisés, telle que la muqueuse orale. Des cellules de ce type ont déjà été décrites précédemment dans la paroi épithéliale des kystes odontogènes périapicaux.Des cellules protéine S-100 positives ont été démontrées par immunocytochimie dans tous nos 142 cas de kystes odontogènes (32 kystes dus à une anomalie de développement; 110 kystes inflammatoires). Leur tropisme pour les revêtements malpighiens peut expliquer leur présence dans la paroi épithéliale des kystes odontogènes. Leur nombre élevé n’est pas exclusivement en corrélation avec les états inflammatoires

    Gingival neoplasm presenting as an ossifying epulis in a parrot cichlid fish (Hoplarchus psittacus)

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    This report describes the histopathological features of an ossifying epulis, measuring 1.5 × 1 × 1 cm in length, width and height, respectively, on the lingual surface of the lower jaw of a 2.5 year-old parrot cichlid (Hoplarchus psittacus) from a commercial aquarium. The tumor had appeared in the oral cavity three months prior to its introduction to the laboratory for diagnosis. Grossly, the neoplastic mass was pale-tan with a shiny, smooth surface and coalescing areas of hemorrhage. Microscopically, the overlying epithelium was hyperplastic and extended deeply into the underlying stroma. The stroma consisted of well vascularized collagenous tissue and neoplastic fibroblasts associated with irregular cords and islands of mineral deposition as dentin-like materials confirmed by Masson's trichrome and Goldner's trichrome staining

    Conjugated linoleic acid stimulates apoptosis in RH and tehran strains of Toxoplasma gondii, in vitro

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    Background: The aim of this study was to evaluate the effects of conjugated linoleic acid (CLA) on apoptosis of tachyzoites of T. gondii, RH strain (type I) and the cyst-forming Tehran strain (type II) in vitro. Methods: Toxoplasma strains were injected into the peritoneal cavity of BALB/c mice. The Tehran strain forms cysts in the brain of mice. Bradyzoites within the cysts are reactivated to proliferative tachyzoites, by dexamethasone. Tachyzoites were aspirated from the peritoneum of infected mice, and the percentage of viable parasites was estimated with trypan blue staining. Tachyzoites were inoculated into HeLa cells cultivated in DMEM medium. Different concentrations of CLA were evaluated on T. gondii in HeLa cells by the tetrazolium (MTT) colorimetric assay. Differentiation between apoptosis and cell death was determined by flow cytometry using Annexin V and propidium iodide (PI) double staining. The statistical analysis performed by GraphPad Prism version 6.00. Results: CLA induces apoptosis in virulent (RH) and avirulent (Tehran) strains of T. gondii. The results of MTT indicated that CLA could decrease the proliferation of tachyzoites of both strains in HeLa cells. Conclusion: Conjugated linoleic acid has anti-toxoplasmacidal activity on tachyzoites of T. gondii. Therefore, we recommended further studies on this component in order to achieve a new drug against the parasite. © 2015, Tehran University of Medical Sciences (TUMS). All rights reserved

    Association of TNF-α G308A gene polymorphism in essential hypertensive patients without type 2 diabetes mellitus

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    This study aims to investigate the effects of tumor necrosis factor alpha (TNF-α) G308A gene polymorphism on essential hypertension (EHT) with or without type 2 diabetes mellitus (T2DM). The project was conducted on buccal epithelial and blood cells for case and control patients, respectively. Epithelial cells were obtained from the inner part of the cheeks. Techniques including DNA extraction, polymerase chain reaction (PCR), and restriction fragment length polymorphism (RFLP) were utilized to assess biomarkers of DNA damage. Our results demonstrated significant differences between wild and mutated genotypes among EHT patients without T2DM. We also found a significant association between wild and mutated allele frequencies in EHT patients (P < 0.05). Clinical characteristics between the groups (EHT with or without T2DM and controls) showed statistically significant association (P < 0.05). Overall, we show that G308A polymorphism of the TNF-αgene may be a significant genetic risk factor for EHT without T2DM patients in Malaysia

    Dientamoeba fragilis diagnosis by fecal screening: Relative effectiveness of traditional techniques and molecular methods

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    Introduction: Dientamoeba fragilis, an intestinal trichomonad, occurs in humans with and without gastrointestinal symptoms. Its presence was investigated in individuals referred to Milad Hospital, Tehran. Methodology: In a cross-sectional study, three time-separated fecal samples were collected from 200 participants from March through June 2011. Specimens were examined using traditional techniques for detecting D. fragilis and other gastrointestinal parasites: direct smear, culture, formalin-ether concentration, and iron-hematoxylin staining. The presence of D. fragilis was determined using PCR assays targeting 5.8S rRNA or small subunit ribosomal RNA. Results: Dientamoeba fragilis, Blastocystis sp., Giardia lamblia, Entamoeba coli, and Iodamoeba butschlii were detected by one or more traditional and molecular methods, with an overall prevalence of 56.5. Dientamoeba was not detected by direct smear or formalin-ether concentration but was identified in 1 and 5 of cases by culture and iron-hematoxylin staining, respectively. PCR amplification of SSU rRNA and 5.8S rRNA genes diagnosed D. fragilis in 6 and 13.5, respectively. Prevalence of D. fragilis was unrelated to participant gender, age, or gastrointestinal symptoms. Conclusions: This is the first report of molecular assays to screen for D. fragilis in Iran. The frequent finding of D. fragilis via fecal analysis indicated the need to include this parasite in routine stool examination in diagnostic laboratories. As the length of amplification target correlates to the sensitivity of PCR, this assay targeting the D. fragilis 5.8S rRNA gene seems optimal for parasite detection and is recommended in combination with conventional microscopy for diagnosing intestinal parasites. © 2018 Hamidi et al

    Dientamoeba fragilis diagnosis by fecal screening: Relative effectiveness of traditional techniques and molecular methods

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    Introduction: Dientamoeba fragilis, an intestinal trichomonad, occurs in humans with and without gastrointestinal symptoms. Its presence was investigated in individuals referred to Milad Hospital, Tehran. Methodology: In a cross-sectional study, three time-separated fecal samples were collected from 200 participants from March through June 2011. Specimens were examined using traditional techniques for detecting D. fragilis and other gastrointestinal parasites: direct smear, culture, formalin-ether concentration, and iron-hematoxylin staining. The presence of D. fragilis was determined using PCR assays targeting 5.8S rRNA or small subunit ribosomal RNA. Results: Dientamoeba fragilis, Blastocystis sp., Giardia lamblia, Entamoeba coli, and Iodamoeba butschlii were detected by one or more traditional and molecular methods, with an overall prevalence of 56.5. Dientamoeba was not detected by direct smear or formalin-ether concentration but was identified in 1 and 5 of cases by culture and iron-hematoxylin staining, respectively. PCR amplification of SSU rRNA and 5.8S rRNA genes diagnosed D. fragilis in 6 and 13.5, respectively. Prevalence of D. fragilis was unrelated to participant gender, age, or gastrointestinal symptoms. Conclusions: This is the first report of molecular assays to screen for D. fragilis in Iran. The frequent finding of D. fragilis via fecal analysis indicated the need to include this parasite in routine stool examination in diagnostic laboratories. As the length of amplification target correlates to the sensitivity of PCR, this assay targeting the D. fragilis 5.8S rRNA gene seems optimal for parasite detection and is recommended in combination with conventional microscopy for diagnosing intestinal parasites. © 2018 Hamidi et al

    Processing of aluminum-graphite particulate metal matrix composites by advanced shear technology

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    Copyright @ 2009 ASM International. This paper was published in Journal of Materials Engineering and Performance 18(9) and is made available as an electronic reprint with the permission of ASM International. One print or electronic copy may be made for personal use only. Systematic or multiple reproduction, distribution to multiple locations via electronic or other means, duplications of any material in this paper for a fee or for commercial purposes, or modification of the content of this paper are prohibited.To extend the possibilities of using aluminum/graphite composites as structural materials, a novel process is developed. The conventional methods often produce agglomerated structures exhibiting lower strength and ductility. To overcome the cohesive force of the agglomerates, a melt conditioned high-pressure die casting (MC-HPDC) process innovatively adapts the well-established, high-shear dispersive mixing action of a twin screw mechanism. The distribution of particles and properties of composites are quantitatively evaluated. The adopted rheo process significantly improved the distribution of the reinforcement in the matrix with a strong interfacial bond between the two. A good combination of improved ultimate tensile strength (UTS) and tensile elongation (e) is obtained compared with composites produced by conventional processes.EPSR

    Mapping coherence in measurement via full quantum tomography of a hybrid optical detector

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    Quantum states and measurements exhibit wave-like --- continuous, or particle-like --- discrete, character. Hybrid discrete-continuous photonic systems are key to investigating fundamental quantum phenomena, generating superpositions of macroscopic states, and form essential resources for quantum-enhanced applications, e.g. entanglement distillation and quantum computation, as well as highly efficient optical telecommunications. Realizing the full potential of these hybrid systems requires quantum-optical measurements sensitive to complementary observables such as field quadrature amplitude and photon number. However, a thorough understanding of the practical performance of an optical detector interpolating between these two regions is absent. Here, we report the implementation of full quantum detector tomography, enabling the characterization of the simultaneous wave and photon-number sensitivities of quantum-optical detectors. This yields the largest parametrization to-date in quantum tomography experiments, requiring the development of novel theoretical tools. Our results reveal the role of coherence in quantum measurements and demonstrate the tunability of hybrid quantum-optical detectors.Comment: 7 pages, 3 figure

    Comprehensive detection of recurring genomic abnormalities : a targeted sequencing approach for multiple myeloma

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    Recent genomic research efforts in multiple myeloma have revealed clinically relevant molecular subgroups beyond conventional cytogenetic classifications. Implementing these advances in clinical trial design and in routine patient care requires a new generation of molecular diagnostic tools. Here, we present a custom capture next-generation sequencing (NGS) panel designed to identify rearrangements involving the IGH locus, arm level, and focal copy number aberrations, as well as frequently mutated genes in multiple myeloma in a single assay. We sequenced 154 patients with plasma cell disorders and performed a head-to-head comparison with the results from conventional clinical assays, i.e., fluorescent in situ hybridization (FISH) and single-nucleotide polymorphism (SNP) microarray. Our custom capture NGS panel had high sensitivity (&gt;99%) and specificity (&gt;99%) for detection of IGH translocations and relevant chromosomal gains and losses in multiple myeloma. In addition, the assay was able to capture novel genomic markers associated with poor outcome such as bi-allelic events involving TP53. In summary, we show that a multiple myeloma designed custom capture NGS panel can detect IGH translocations and CNAs with very high concordance in relation to FISH and SNP microarrays and importantly captures the most relevant and recurrent somatic mutations in multiple myeloma rendering this approach highly suitable for clinical application in the modern era
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