383 research outputs found
Combustors based on addition and recirculation of energy
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The effect of temperature on the physical properties of bioceramic sealers
INTRODUCTION: The compatibility of EndoSequence BC Sealer (BC Sealer; Brasseler USA, Savannah, GA) for warm vertical compaction has been questioned due to changing physical properties under higher temperature. The aim was to evaluate the effect of heating on the physical properties (flowability and radiopacity) of a new calcium-based root canal sealer (EndoSequence BC Sealer HiFlow [HiFlow]) in comparison with EndoSequence BC Sealer.
METHODS: The flow, and radiopacity of the 2 sealers were measured according to ISO 6786/2012 at different temperatures. Forty real printed plastic teeth (incisor) were used to evaluate the flowability of the two Standard EndoSequence BC Sealer and HiFlow EndoSequence BC Sealer into the lateral and apical accessory canals. These evaluation was done with two obturation techniques including single cone and warm vertical condensation.
RESULT: The mean flowability was ranging from 22.25 mm to 9.52 mm. The results indicate that there is a statistical difference between the flowability of the two calcium silicate based sealers under all three different temperatures (37˚C, 100˚C and 150˚C). Radiopacity was measured at two different temperatures including 21˚C and 100˚C. The mean gray value ranged from 213.55 to 202.25. Results showed that HiFlow is more radiopaque and there is a statistically significant difference at both temperatures. The results of single cone and warm vertical obturation techniques show that there is no significant difference between the flowability of the two calcium silicate based sealers into the lateral and apical accessory canals at 21°C and there is a significant difference at higher temperatures.
CONCLUSIONS: HiFlow BC sealer had higher flow and was more radiopaque, especially at high temperatures, which are generated by the commonly used warm vertical compaction technique
Characterization of Dynamic Regulatory Gene and Protein Networks in Wheat Roots Upon Perceiving Water Deficit Through Comparative Transcriptomics Survey
A well-developed root system benefits host plants by optimizing water absorption and nutrient uptake and thereby increases plant productivity. In this study we have characterized the root transcriptome using RNA-seq and subsequential functional analysis in a set of drought tolerant and susceptible genotypes. The goal of the study was to elucidate and characterize water deficit-responsive genes in wheat landraces that had been through long-term field and biochemical screening for drought tolerance. The results confirm genotype differences in water-deficit tolerance in line with earlier results from field trials. The transcriptomics survey highlighted a total of 14,187 differentially expressed genes (DEGs) that responded to water deficit. The characterization of these genes shows that all chromosomes contribute to water-deficit tolerance, but to different degrees, and the B genome showed higher involvement than the A and D genomes. The DEGs were mainly mapped to flavonoid, phenylpropanoid, and diterpenoid biosynthesis pathways, as well as glutathione metabolism and hormone signaling. Furthermore, extracellular region, apoplast, cell periphery, and external encapsulating structure were the main water deficit-responsive cellular components in roots. A total of 1,377 DEGs were also predicted to function as transcription factors (TFs) from different families regulating downstream cascades. TFs from the AP2/ERF-ERF, MYB-related, B3, WRKY, Tify, and NAC families were the main genotype-specific regulatory factors. To further characterize the dynamic biosynthetic pathways, protein-protein interaction (PPI) networks were constructed using significant KEGG proteins and putative TFs. In PPIs, enzymes from the CYP450, TaABA8OH2, PAL, and GST families play important roles in water-deficit tolerance in connection with MYB13-1, MADS-box, and NAC transcription factors
Alkali Metasomatism and Th-REE Mineralization in the Choghart deposit, Bafq district, Central Iran
The Choghart iron oxide-apatite (IOA) deposit is located 124 km southeast of Yazd, in the Bafq district within the Central Iranian microcontinent. The Choghart deposit is hosted by the rhyolitic rocks of the Early Cambrian volcano-sedimentary sequence (the Esfordi formation). Both host rocks and the orebodies are crosscut by diabase dykes. Tectonically, the Choghart rhyolites represent the continental margin setting and the Choghart diabase dykes formed in the back-arcbasin environment, respectively, indicating that the evolution of the Bafq district is associated with subduction of Palaeotethys oceanic crust beneath the Central Iranian microcontinent followed by formation of continental arc related granitoids and rhyolites and then formation of back-arc basin diabase dykes. Similar to the other subduction-related rhyolites, the Choghart rhyolite is enriched in Th and LREE compared to Ia, Nb, and HREE.The main host minerals of Th and REE in the Th-REE mineralization zone are thorite and sphene. Albitization is the most important alteration aspect related to Th-REE mineralization (mainly Th, La, Ce, Nd, and Y). In addition to albite, Th-REE mineralization is associated with actinolite, augite, diopside, minor microcline and orthoclase, plus magnetite, calcite, pyrite, rutile, and minor amounts of chalcopyrite. The negative Eu anomaly in Th mineralization zone, as well as the paragenetic occurrence of magnetite, pyrite and chalcopyrite with thorite suggest that Th-REE mineralization formed in relatively reduced condition. The presence of paragenetic calcite accompanied by thorite and sphene in the Th-REE mineralization zone indicates that Th and REE were likely transported by the carbonate complexes in the mineralizing fluids. The similarity betweenthe chondrite-normalized REE patterns of the host rhyolite and the Th-REE mineralization zone suggests that post-magmatic driven fluids of continental margin rhyolitic magma played an important role in Th-REE mineralization.</p
Chemical chaperone treatment reduces intracellular accumulation of mutant collagen IV and ameliorates the cellular phenotype of a COL4A2 mutation that causes haemorrhagic stroke
Haemorrhagic stroke accounts for approximately 20% of stroke cases and porencephaly is a clinical consequence of perinatal cerebral haemorrhaging. Here we report the identification of a novel dominant G702D mutation in the collagen domain of COL4A2 (collagen IV alpha chain 2) in a family displaying porencephaly with reduced penetrance. COL4A2 is the obligatory protein partner of COL4A1 but in contrast to most COL4A1 mutations, the COL4A2 mutation does not lead to eye or kidney disease. Analysis of dermal biopsies from patient and his unaffected father, who also carries the mutation, revealed that both display basement membrane (BM) defects. Intriguingly, defective collagen IV incorporation into the dermal BM was only observed in the patient and was associated with endoplasmic reticulum (ER) retention of COL4A2 in primary dermal fibroblasts. This intracellular accumulation led to ER-stress, unfolded protein response activation, reduced cell proliferation and increased apoptosis. Interestingly, absence of ER retention of COL4A2 and ER-stress in cells from the unaffected father indicate that accumulation and/or clearance of mutant COL4A2 from the ER may be a critical modifier for disease development. Our analysis also revealed that mutant collagen IV is degraded via the proteasome. Importantly, treatment of patient cells with a chemical chaperone decreased intracellular COL4A2, ER-stress and apoptosis, demonstrating that reducing intracellular collagen accumulation can ameliorate the cellular phenotype of COL4A2 mutations. Importantly, these data highlight that manipulation of chaperone levels, intracellular collagen accumulation and ER-stress are potential therapeutic options for collagen IV diseases including haemorrhagic stroke
Construction and characterization of a new chimeric antibody against HER2
Aim: Immunotherapy with anti-HER2 antibodies has shown promising results in patients with HER2-positive breast cancer. We have recently reported characterization of a mouse monoclonal antibody (mAb) against HER2, which binds to an epitope different from that recognized by trastuzumab and specifically inhibits proliferation of tumor cells overexpressing HER2. In the present study we report chimerization of this antibody.
Materials & methods: The immunoglobulin variable region heavy and light chain genes of 1T0 hybridoma cells were amplified and ligated to human -1 and constant region genes using splice overlap extension PCR. The chimeric antibody was subsequently expressed and characterized by ELISA, western blot and flow cytometry.
Results: The purified chimeric antibody specifically binds to recombinant HER2 and HER2-overexpressing tumor cells and inhibits proliferation of these cells. The binding affinity of the chimeric mAb was comparable with the parental mouse mAb.
Conclusion: This chimeric anti-HER2 mAb is a potentially valuable tool for targeted immunotherapy.noneManuscrip
Amino Acids Are an Ineffective Fertilizer for Dunaliella spp. Growth
Autotrophic microalgae are a promising bioproducts platform. However, the fundamental requirements these organisms have for nitrogen fertilizer severely limit the impact and scale of their cultivation. As an alternative to inorganic fertilizers, we investigated the possibility of using amino acids from deconstructed biomass as a nitrogen source in the genus Dunaliella. We found that only four amino acids (glutamine, histidine, cysteine, and tryptophan) rescue Dunaliella spp. growth in nitrogen depleted media, and that supplementation of these amino acids altered the metabolic profile of Dunaliella cells. Our investigations revealed that histidine is transported across the cell membrane, and that glutamine and cysteine are not transported. Rather, glutamine, cysteine, and tryptophan are degraded in solution by a set of oxidative chemical reactions, releasing ammonium that in turn supports growth. Utilization of biomass-derived amino acids is therefore not a suitable option unless additional amino acid nitrogen uptake is enabled through genetic modifications of these algae
Comparative expression profile of orphan receptor tyrosine kinase ROR1 in Iranian patients with lymphoid and myeloid leukemias
It has recently been shown that ROR1, a member of the receptor tyrosine kinase family, is overexpressed in leukemic B cells of Chronic Lymphocytic Leukemia (CLL) and a subset of Acute Lymphoblastic Leukemia (ALL). In this comparative study the expression profile of ROR1 mRNA was investigated in Iranian patients with CLL and Acute Myelogenous Leukemia (AML) and the results were compared with those previously reported in our Iranian ALL patients. RT-PCR was performed on bone marrow and/or peripheral blood samples of 84 CLL and 12 AML patients. CLL samples were classified into immunoglobulin heavy chain variable region (IGHV) gene mutated (n = 55) and unmutated (n = 29) and also indolent (n = 42) and progressive (n = 39) subtypes. ROR1 expression was identified in 94% of our CLL patients, but none of the AML patients expressed ROR1. No significant differences were observed between different CLL subtypes for ROR1 expression. Taken together the present data and our previous results on ROR1 expression in ALL, our findings propose ROR1 as a tumor-associated antigen overexpressed in a large proportion of lymphoid (CLL and ALL), but not myeloid (AML) leukemias. Expression of ROR1 seems to be associated to lineage and differentiation stages of leukemic cells with a potential implication for immunotherapy.Tehran University of Medical SciencesPublishe
Comparative expression profile of orphan receptor tyrosine kinase ror1 in iranian patients with lymphoid and myeloid leukemias
It has recently been shown that ROR1, a member of the receptor tyrosine
kinase family, is overexpressed in leukemic B cells of Chronic Lymphocytic
Leukemia (CLL) and a subset of Acute Lymphoblastic Leukemia (ALL). In this
comparative study the expression profile of ROR1 mRNA was investigated in
Iranian patients with CLL and Acute Myelogenous Leukemia (AML) and the
results were compared with those previously reported in our Iranian ALL
patients. RT-PCR was performed on bone marrow and/or peripheral blood
samples of 84 CLL and 12 AML patients. CLL samples were classified into immunoglobulin
heavy chain variable region (IGHV) gene mutated (n=55) and
unmutated (n=29) and also indolent (n=42) and progressive (n=39) subtypes.
ROR1 expression was identified in 94% of our CLL patients, but none of the
AML patients expressed ROR1. No significant differences were observed between
different CLL subtypes for ROR1 expression. Taken together the present
data and our previous results on ROR1 expression in ALL, our findings propose
ROR1 as a tumor-associated antigen overexpressed in a large proportion of
lymphoid (CLL and ALL), but not myeloid (AML) leukemias. Expression of
ROR1 seems to be associated to lineage and differentiation stages of leukemic
cells with a potential implication for immunotherapy.Tehran University of Medical Sciences and the Ministry of Health and Medical Education of Iran.Publishe
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Influence of the Location and Zone of Tumor in Prostate Cancer Detection and Localization on 3-T Multiparametric MRI Based on PI-RADS Version 2.
OBJECTIVE. The objective of our study was to determine the performance of 3-T multiparametric MRI (mpMRI) for prostate cancer (PCa) detection and localization, stratified by anatomic zone and level, using Prostate Imaging Reporting and Data System version 2 (PI-RADSv2) and whole-mount histopathology (WMHP) as reference. MATERIALS AND METHODS. Multiparametric MRI examinations of 415 consecutive men were compared with thin-section WMHP results. A genitourinary radiologist and pathologist collectively determined concordance. Two radiologists assigned PI-RADSv2 scores and sector location to all detected foci by consensus. Tumor detection rates were calculated for clinical and pathologic (tumor location and zone) variables. Both rigid and adjusted sector-matching models were used to account for fixation-related issues. RESULTS. Of 863 PCa foci in 16,185 prostate sectors, the detection of overall and index PCa lesions in the midgland, base, and apex was 54.9% and 83.1%, 42.1% and 64.0% (p = 0.04, p = 0.02), and 41.9% and 71.4% (p = 0.001, p = 0.006), respectively. Tumor localization sensitivity was highest in the midgland compared with the base and apex using an adjusted match compared with a rigid match (index lesions, 71.3% vs 43.7%; all lesions, 70.8% vs 36.0%) and was greater in the peripheral zone (PZ) than in the transition zone. Three-Tesla mpMRI had similarly high specificity (range, 93.8-98.3%) for overall and index tumor localization when using both rigid and adjusted sector-matching approaches. CONCLUSION. For 3-T mpMRI, the highest sensitivity (83.1%) for detection of index PCa lesions was in the midgland, with 98.3% specificity. Multiparametric MRI performance for sectoral localization of PCa within the prostate was moderate and was best for index lesions in the PZ using an adjusted model
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