Identification of rice hybrids using microsatellite and RAPD markers

Having produced a series of hybrid rice varieties especially the first Iranian hybrid rice (IRH1), fingerprinting and genetic purity determination of hybrid seeds were conducted using microsatellite(SSR) and random amplified polymorphic DNA (RAPD) markers. Sixteen rice genotypes including 3 cytoplasmic male sterile (CMS) lines, 5 restorer lines and their 8 hybrid combinations were used in thisstudy. Ten out of fourteen SSR markers produced polymorphic bands in the 16 rice genotypes. The first Iranian hybrid rice, IRH1, could be differentiated from other hybrids possessing a unique SSRfingerprint. Although the SSR markers amplified the unique fingerprints for the restorer lines, they could not differentiate between 2 CMS lines (Neda-A and Nemat-A) and their resultant hybrids. The rice CMSlines and restorer lines could be uniquely identified by RAPD multilocus amplified profile at 7 informative loci. Cluster analysis based on shared alleles and Jaccard’s similarity coefficient using UPGMA algorithm, grouped the rice genotypes into 3 and 4 major clusters according to their microsatellite and RAPD fragment similarities respectively. Non-parental bands were also observed in addition to parental bands which probably correspond to heteroduplex molecules formed by two allelic sequences of different amplified fragments. This demonstrates that heteroduplex bands can be an indicative feature for identifying hybrid individuals

Application of a hazard and operability study method to hazard evaluation of a chemical unit of the power station.

BACKGROUND: The aim of this study was to identify the hazards, evaluate their risk factors and determine the measure for promotion of the process and reduction of accidents in the chemical unit of the power station. METHODS: In this case and qualitative study, HAZOP technique was used to recognize the hazards and problems of operations on the chemical section at power station. Totally, 126 deviations were documented with various causes and consequences. RESULTS: Ranking and evaluation of identified risks indicate that the majority of deviations were categorized as "acceptable" and less than half of that were "unacceptable". The highest calculated risk level (1B) related to both the interruption of acid entry to the discharge pumps and an increased density of the acid. About 27% of the deviations had the lowest risk level (4B). CONCLUSION: The identification of hazards by HAZOP indicates that it could, systemically, assess and criticize the process of consumption or production of acid and alkali in the chemical unit of power plant

Influence of spark plasma sintering and baghdadite powder on mechanical properties of hydroxyapatite

AbstractSince hydroxyapatite-based materials have similar composition and crystallinity as natural calcified tissues, can be used for bone/tissue engineering. In the present study a novel nanocomposite based on bioceramics such as Natural Hydroxyapatite (NHA) and Baghdadite (BAG), was sintered by spark plasma sintering (SPS) technique. The prepared composite was characterized using scanning electron microscopy (SEM), X-ray diffractometer (XRD) and Brunauer–Emmett–Teller (BET) techniques. The porosity of the samples was measured by Archimedes method. The cold crushing strength (CCS) test was applied to evaluate their mechanical properties. Our results demonstrated that NHA-30wt. %BAG nanocomposite specimens have the lower CCS in comparison with other examined composites. Consequently, NHA/BAG samples exhibited acceptable mechanical properties and could be suitable candidates for bone tissue engineering applications especially orthopaedic fields

A process mineralogy approach to optimize molybdenite flotation in copper � molybdenum processing plants

The Sungun copper-molybdenum operation in Iran uses a typical copper-molybdenum flowsheet to produce separate copper and molybdenum concentrates through flotation and regrinding of the rougher concentrates arising from the primary circuit. This site was used as a case study limited to the feed and products of the copper-molybdenum separation circuit, in which process mineralogy might improve the quality of the molybdenum concentrate thorough diagnostic analysis of key flowsheet streams. The undesirable presence of copper in the molybdenum concentrate was identified as a key focus for the investigation by process mineralogy, which has a history of successful process diagnosis. This is because it develops information on minerals, which is far more informative than chemical assays alone. Together with the assays, the mineralogical data inform the investigator of the type and quantity of minerals present, their state of liberation and textural associations, and metal recovery. A key finding was that the appearance of chalcopyrite in the molybdenum concentrate was due to the presence of a chalcopyrite-pyrite texture that avoided the chalcopyrite depression in the molybdenum circuit because of suitable pyrite flotation conditions. Recovery of liberated pyrite to this concentrate also diluted the molybdenum concentrate. The open-circuit format of the regrind circuit also contributed to the unnecessary production of ultrafine particles. This flaw expressed itself as ultrafine losses of molybdenite to the flotation tailings. © 202

A Comparative Study of Cervical Composite Restorations Microleakage Using Dental Universal Bonding and Two-step Self-etch Adhesive

© 2021. The Author(s). Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by-nc/4.0/), which permits unrestricted use, distribution, and non-commercial reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.Aim: The aim of this study is to compare microleakage of cervical restorations using universal bonding and two-step self-etch adhesive with or without enamel etching through a dye penetration testing method. Materials and methods: In this in vitro experimental study, 70 maxillary premolar teeth with no anomaly or decay were randomly divided into five groups of 14. Conventional cervical cavities were prepared with diamond bur on the facial surface of the teeth. The teeth were prepared using G-Premio Bond/self-etch technique, G-Premio Bond/total-etch technique, G-Premio Bond/selective-etch technique, Clearfil SE Bond/ self-etch technique, and Clearfil SE Bond/selective-etch technique in Groups I to V, respectively, and restored with composite. Microleakage at the occlusal enamel margin and the cervical dentinal margin was ranked from 0 to 4 based on dye penetration using stereomicroscope (×32). Statistical analysis was carried out using Kruskal-Wallis and Mann-Whitney tests at a significance level of α = 0.05. Results: The mean occlusal microleakage in the five study groups was 1.07, 0.57, 0.57, 1.28, and 0.78, respectively. The mean cervical microleakage was 0.97, 0.85, 0.64, 1.35, and 1.14, respectively. Kruskal-Wallis test showed significant difference between the microleakage scores of different groups in enamel (p = 0.022) and dentin (p = 0.01). Clearfil SE Bond/self-etch technique group showed the highest mean score of microleakage in enamel margins, and G-Premio Bond/total-etch technique and G-Premio Bond/selective-etch technique groups showed lowest enamel microleakage mean. Clearfil SE Bond/self-etch group showed the highest mean score of microleakage in dentin margins, while G-Premio Bond/ selective-etch technique group showed the lowest mean score of dentin microleakage. Conclusion: Selective etching of enamel will decrease enamel microleakage. G-Premio Bond shows better microleakage results in comparison to Clearfil SE Bond in dentinal margins. Clinical significance: A major problem in cervical composite restorations is the presence of microleakage in the cervical wall. Different adhesive systems have been designed to overcome this problem

Titanium mesh-reinforced calcium sulfate for structural bone grafts

Calcium sulfate (CS) possesses many of the requirements for an ideal bone graft material: it is biodegradable, biocompatible, and osteoconductive. However, its relatively low strength and brittleness are major obstacles to its use as a structural bone implant. Although the strength of CS can be improved by reducing porosity, its brittleness remains a major obstacle towards its use as bone graft. Here we combine two powerful toughening strategies which are found in advanced ceramics and in natural bone: Multi-layered architectures and ductile reinforcements. We first used stress analysis and micromechanics to generate design guidelines that ensure the proper failure sequence and maximize properties. We then fabricated and tested fully dense CS by hydrostatic compression layered with layers of titanium woven mesh. Flexural experiments in hydrated conditions confirmed that the ductility and strength of titanium and the adhesion at the titanium-CS interfaces (controlled by the size of the Ti mesh) are critical factors in the mechanical performance of the composite. Our best design exhibited a toughness 180 times larger than that of plain CS, together with a 46% increase in strength.</p