43 research outputs found
Recommended from our members
Downward heat transfer in a miscible melting system
The integrity of an ex-vessel core-retention system in the event of core meltdown is of concern in PAHR safety assessment. Several ex-vessel core retention concepts incorporate sacrificial beds. The integrity of the ex-vessel core-retention system is dependent on the directional growth of the molten pool into soluble boundaries of the sacrificial bed. Mutual dissolution of the molten pool of core-debris and the sacrificial material is expected to change the thermal characteristics of the pool and thus affect the heat transfer to the boundaries. The two-dimensional simulation study of the penetration of a dense, hot liquid pool into the boundaries of a meltable, soluble solid revealed the dependency of the directional pool growth on the density ratio, rho*, of the liquid pool to the meltable solid. In the one-dimensional study of the downward penetration of the hot pool into a soluble boundary four different hydrodynamic flow regimes were identified that occurred at different ranges of rho*. The downward heat transfer enhanced beyond rho* approx. = 1.1. The present study investigates the effect of test cell geometry and material properties on the downward heat transfer in a horizontal melting system
Expression of genes for bone morphogenetic proteins BMP-2, BMP-4 and BMP-6 in various parts of the human skeleton
BACKGROUND: Differences in duration of bone healing in
various parts of the human skeleton are common experience for
orthopaedic surgeons. The reason for these differences is not obvious
and not clear.METHODS: In this paper we decided to
measure by the use of real-time RT-PCR technique the level of expression
of genes for some isoforms of bone morphogenetic proteins (BMPs), whose
role is proven in bone formation, bone induction and bone turnover.
Seven bone samples recovered from various parts of skeletons from six
cadavers of young healthy men who died in traffic accidents were
collected. Activity of genes for BMP-2, -4 and -6 was measured by the
use of fluorescent SYBR Green I.RESULTS: It was found
that expression of m-RNA for BMP-2 and BMP-4 is higher in trabecular
bone in epiphyses of long bones, cranial flat bones and corpus
mandibulae then in the compact bone of diaphyses of long bones. In all
samples examined the expression of m-RNA for BMP-4 was higher than for
BMP-2.CONCLUSION: It was shown that m-RNA for BMP-6 is
not expressed in the collected samples at all. It is postulated that
differences in the level of activation of genes for BMPs is one of the
important factors which determine the differences in duration of bone
healing of various parts of the human skeleton.Author has checked copyrightDG 16/11/1
Genome-Wide Association Study for Femoral Neck Bone Geometry
Poor femoral neck bone geometry at the femur is an important risk factor for hip fracture. We conducted a genome-wide association study (GWAS) of femoral neck bone geometry, examining approximately 379,000 eligible single-nucleotide polymorphisms (SNPs) in 1000 Caucasians. A common genetic variant, rs7430431 in the receptor transporting protein 3 (RTP3) gene, was identified in strong association with the buckling ratio (BR, P = 1.6 Γ 10β7), an index of bone structural instability, and with femoral cortical thickness (CT, P = 1.9 Γ 10β6). The RTP3 gene is located in 3p21.31, a region that we found to be linked with CT (LOD = 2.19, P = 6.0 Γ 10β4) in 3998 individuals from 434 pedigrees. The replication analyses in 1488 independent Caucasians and 2118 Chinese confirmed the association of rs7430431 to BR and CT (combined P = 7.0 Γ 10β3 for BR and P = 1.4 Γ 10β2 for CT). In addition, 350 hip fracture patients and 350 healthy control individuals were genotyped to assess the association of the RTP3 gene with the risk of hip fracture. Significant association between a nearby common SNP, rs10514713 of the RTP3 gene, and hip fracture (P = 1.0 Γ 10β3) was found. Our observations suggest that RTP3 may be a novel candidate gene for femoral neck bone geometry. Β© 2010 American Society for Bone and Mineral Researc
Preoperative neutrophil-to-lymphocyte ratio is an independent prognostic marker in patients with laryngeal squamous cell carcinoma
Identification of microRNA profile specific to cancer stem-like cells directly isolated from human larynx cancer specimens
Experimental Studies of Penetration of a Hot Liquid Pool into a Melting Miscible Substrate
Effect of the Fluid Media Viscosities on the Downward Heat Transfer in a Miscible, Melting System
Recommended from our members
Simulation experiments on the radial pool growth in gas-releasing melting system. [PWR; BWR]
Following an HCDA, molten core-debris can contact the concrete foundation of the reactor building resulting in a molten UO/sub 2//concrete interaction and considerable gas release. The released gas can pressurize the containment building potentially leading to radiological releases. Furthermore, directional growth of the molten core-debris pool can reduce the reactor building structural integrity. To implement design changes that insure structural integrity, an understanding of the thermal-hydraulic and mass-transfer process associated with such a growth is most desirable. Owing to the complex nature of the combined heat, mass, and hydrodynamic processes associated with the two-dimensional problem of gas release and melting, the downward and radial penetration problems have been investigated separately. The present experimental study addresses the question of sideward penetration of the molten core debris into a gas-releasing, meltable, miscible solid