2,624 research outputs found

    A unified numerical model of collisional depolarization and broadening rates due to hydrogen atom collisions

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    Interpretation of solar polarization spectra accounting for partial or complete frequency redistribution requires data on various collisional processes. Data for depolarization and polarization transfer are needed but often missing, while data for collisional broadening are usually more readily available. Recent work by Sahal-Br\'echot and Bommier concluded that despite underlying similarities in the physics of collisional broadening and depolarization processes, relationships between them are not possible to derive purely analytically. We aim to derive accurate numerical relationships between the collisional broadening rates and the collisional depolarization and polarization transfer rates due to hydrogen atom collisions. Such relationships would enable accurate and efficient estimation of collisional data for solar applications. Using earlier results for broadening and depolarization processes based on general (i.e. not specific to a given atom), semi-classical calculations employing interaction potentials from perturbation theory, genetic programming (GP) has been used to fit the available data and generate analytical functions describing the relationships between them. The predicted relationships from the GP-based model are compared with the original data to estimate the accuracy of the method.Comment: 10 pages, 7 figures, Accepted for publication in Astronomy & Astrophysic

    Nanomagnetic-Mediated Drug Delivery for The Treatment of Dental Disease

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    Maintaining the vitality of the dental pulp, the highly innervated and highly vascular, innermost layer of the tooth, is a critical goal of any dental procedure. Upon injury, targeting the pulp with specific therapies is challenging because it is encased in hard tissues. This project describes a method that can effectively deliver therapeutic agents to the pulp. This method relies on the use of nanoparticles that can be actively steered using magnetic forces to the pulp, traveling through naturally occurring channels in the dentin (the middle layer of the tooth). This method can reduce the inflammation of injured pulp and improve the penetration of dental adhesives into dentin. Such a delivery method would be less expensive, and both less painful and less traumatic than existing therapeutic options available for treatment of injured dental pulp. This technique would be simple and could be readily translated to clinical use

    Outcomes of deep hypothermic circulatory arrest in pediatric cardiac surgery: A single center experience

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    AbstractBackgroundDeep hypothermic circulatory arrest (DHCA) is a technique used in the repair of complex congenital cardiac lesions that require aortic arch or pulmonary vein repair. DHCA has been linked to adverse outcomes and neurologic complications. Selective cerebral perfusion (SCP) may be added to DHCA to prevent neurological complication. Air embolism and hyperperfusion injury may be encountered. The aim of this study was to evaluate the safety and efficacy of simple DHCA and to outline the early outcomes especially the neurological ones.MethodsTwenty nine patients underwent surgical repair of congenital cardiac lesion with DHCA at a single institution from January 2010 to November 2015. DHCA was conducted with a target esophageal temperature of 18° and placement of an ice pack on the head. No selective perfusion was done. Demographic, operative and postoperative data were reviewed. Mortality, any neurological complications including seizers, coma, and stroke were recorded.ResultsThe mean age was 20.6 ± 8.2 months (range: 9 days to 154 months). The majority were males (20, 69%). The mean weight was 5.57 ± 4.2 kg (range: 2.3–17.5 kg). DHCA time was 20.03 min (range 3–52 min). There were three (10.3%) deaths. Two deaths occurred after Norwood operation, and one after interrupted aortic arch repair. None of the deaths were related to neurological injury. None of the patients developed seizers, coma, abnormal movement or neurological deficits.ConclusionsSimple DHCA without SCP is a safe, expeditious and reliable method for brain protection during repair of complex cardiac lesions, with acceptable outcomes

    Applying of No-fines concretes as a porous concrete in different construction application

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    Recently, the demands on the concretes with no fines aggregate has been increased as a results of the industry revolution. Many researchers are trying to recycle the concretes and rubble. In addition, the increase in noise in the surrounding environment as a result of the growing population and cars has generated an urgent need to produce concretes characterized by good sound insulation. No-fines concretes is considered as a kind of porous lightweights concretes, gained by removing the sand from the ordinary concretes mixture. The aim of this study is replace the coarse aggregate by waste ceramics in order to reduce the wastes as well as investigate strengths against compression s, density and porosity of No-fines concretes before and after substitution the coarse aggregate by waste ceramics. The methodology of this research paper has been mainly depending on strengths against compression s test and the measured ultrasonic pulse velocity as well as the density. The investigational research has been implemented by 54 samples cast by six various blending proportion consisting of (cement, coarse aggregate, water) utilizing ceramic wastes (CWs) as a substation ratio of coarse aggregates in making concretes free of fine aggregate, so that the proportions of ceramic residues are (0, 10%, 20, 30, 40, 50) as a partial substation of the coarse aggregates and examined at the ages of (7, 28 and 90) days. The mechanism of failure has been detected and categorized beside the concrete’s density and void percentage have been collected. The results show that, the increasing the substitution ratio for waste ceramic within the no-fine mixtures cause a decrease in the density with increasing the strengths against compression s for the specimens

    EXAMINATION OF AGILITY FACTORS OF JUNIOR FOOTBALL PLAYERS INBAÄŒKA TOPOLA, SERBIA

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    The project was designed to collect data about junior football players using complex instrumental measurements. Agility is the ability to move easily and quickly; it infers rapid onset, sudden stops and changes in direction. The execution of these requires complex skill set. In modern football, this factor is considered the most important one in terms of efficiency. Several previous studies have, with no significant results, tried to find a link between individual skills and agility. In the present research we were looking for answers to what factors influence agility among junior football players.According to the of the movement-structure analysis of these tests, it is possible, that separately they do not cover the whole scale of movement patterns which could be present during a match. Because of this, we promoted two new variables: There are the "Agility without ball" and the "Agility with ball". This test of movement structure contains all the components which could be expected of the players during a match, such as changes of direction, dribbles, using the dominant and subdominant leg separately and optionally.In modern football, agility is an extremely complex skill, and the exact structure of its performance components is hard to define. The factors influencing players' agility should be emphasized and methodically developed in youth training in the light of future efficiency

    Evaluation of FHIT gene alterations in ovarian cancer.

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    The FHIT gene, recently cloned and mapped on chromosome 3p14.2, has frequently been found to be abnormal in several established cancer cell lines and primary tumours. As alterations of chromosome 3p are common events in ovarian cancers with breakpoint sites at 3p14.2, we decided to investigate the role of FHIT in human ovarian tumorigenesis. Fifty-four primary ovarian carcinomas were studied by reverse transcription of FHIT mRNA followed by polymerase chain reaction (PCR) amplification and sequencing of products. The same tumours and matched normal tissues were also investigated for loss of heterozygosity using three microsatellite markers located inside the gene. We found an abnormal transcript of the FHIT gene in two cases (4%) and allelic losses in eight cases (15%). Twelve (22%) of the 54 tumours investigated belonged to young patients with a family history of breast/ovarian cancer. In none of these cases was the FHITgene found to be altered. Our results indicate that FHITplays a role in a small proportion of ovarian carcinomas
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