71 research outputs found
Chromosome 9p deletion in clear cell renal cell carcinoma predicts recurrence and survival following surgery
BACKGROUND: Wider clinical applications of 9p status in clear cell renal cell carcinoma (ccRCC) are limited owing to the lack of validation and consensus for interphase fluorescent in situ hybridisation (I-FISH) scoring technique. The aim of this study was to analytically validate the applicability of I-FISH in assessing 9p deletion in ccRCC and to clinically assess its long-term prognostic impact following surgical excision of ccRCC. METHODS: Tissue microarrays were constructed from 108 renal cell carcinoma (RCC) tumour paraffin blocks. Interphase fluorescent in situ hybridisation analysis was undertaken based on preset criteria by two independent observers to assess interobserver variability. 9p status in ccRCC tumours was determined and correlated to clinicopathological variables, recurrence-free survival and disease-specific survival. RESULTS: There were 80 ccRCCs with valid 9p scoring and a median follow-up of 95 months. Kappa statistic for interobserver variability was 0.71 (good agreement). 9p deletion was detected in 44% of ccRCCs. 9p loss was associated with higher stage, larger tumours, necrosis, microvascular and renal vein invasion, and higher SSIGN (stage, size, grade and necrosis) score. Patients with 9p-deleted ccRCC were at a higher risk of recurrence (P=0.008) and RCC-specific mortality (P=0.001). On multivariate analysis, 9p deletion was an independent predictor of recurrence (hazard ratio 4.323; P=0.021) and RCC-specific mortality (hazard ratio 4.603; P=0.007). The predictive accuracy of SSIGN score improved from 87.7% to 93.1% by integrating 9p status to the model (P=0.001). CONCLUSIONS: Loss of 9p is associated with aggressive ccRCC and worse prognosis in patients following surgery. Our findings independently confirm the findings of previous reports relying on I-FISH to detect 9p (CDKN2A) deletion
Dynamic replication strategies in data grid systems: A survey
In data grid systems, data replication aims to increase availability, fault tolerance, load balancing and scalability while reducing bandwidth consumption, and job execution time. Several classification schemes for data replication were proposed in the literature, (i) static vs. dynamic, (ii) centralized vs. decentralized, (iii) push vs. pull, and (iv) objective function based. Dynamic data replication is a form of data replication that is performed with respect to the changing conditions of the grid environment. In this paper, we present a survey of recent dynamic data replication strategies. We study and classify these strategies by taking the target data grid architecture as the sole classifier. We discuss the key points of the studied strategies and provide feature comparison of them according to important metrics. Furthermore, the impact of data grid architecture on dynamic replication performance is investigated in a simulation study. Finally, some important issues and open research problems in the area are pointed out
Bauteil mit Schweissnaht und Verfahren zur Herstellung einer Schweissnaht
(A1) Beim Schweissen treten oft Risse am Ende der Schweissnaht auf. Beim erfindungsgemaessen Verfahren, bei dem die Leistung am Ende (53) der Schweissnaht (10) reduziert wird, wird die Entstehung von Rissen reduziert
The relationship between riveting lithium isotope composition and silicate weathering rates in Iceland
This study presents lithium isotope and elemental data for the dissolved phase and suspended and bedload sediments of the major Icelandic rivers. For the dissolved phase, δ7Li values range between 10.1‰ and 23.8‰, while river sediments display lower and much more homogeneous values (δ7Li = 3.1‰-4.8‰), close to the composition of unweathered Mid-Ocean Ridge Basalt (MORB). High δ7Li values are associated with high K/Li, Na/Li and Mg/Li ratios, in waters draining mainly old and weathered basalt catchments, whereas low δ7Li rivers are located in younger parts of the island. Simple mixing between precipitation, Li-rich hydrothermal springs and basalt weathering is unable to explain the entire range of δ7Li values. Instead, a simple model of Li uptake by secondary minerals, associated with clay-water Li isotope fractionation (Δ7Li ranging from - 1‰ to - 7.5‰) can explain both water and sediment δ7Li values. A negative correlation is observed between basalt chemical erosion rates and δ7Li measured in Icelandic rivers, and an empirical law is inferred. Comparison with literature data suggests that this relationship may be applicable at a more global scale, and, if confirmed, could be of particular use for estimating the evolution of continental weathering preserved in marine sedimentary records. However, more data are now needed for rivers draining silicates typical of the continental crust, in order to refine large scale modelling. © 2009 Elsevier B.V. All rights reserved
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238U–230Th disequilibrium in recent basalts and dynamic melting beneath the Kenya rift.
Trace element and U-series isotope analyses are presented for a suite of recent ( 10 × chondrite and the LREE between 60 and 200 × chondrite. REE fractionation is consistent with melting a garnet lherzolite source region with between 2% and 6% modal garnet. Other trace element ratios are distinct from OIB, notably Zr/Hf which ranges from 43 to 48, whilst at a given Zr content the Zr/Hf ratio is significantly greater than that found in OIB. (238U/232Th) range from 0.362 to 1.036, (230Th/232Th) from 0.503 to 1.109, with (230Th/238U) ranging from 0.783 to 2.966. All but two samples are in 230Th excess or in secular equilibrium. Samples with elevated (238U/232Th), also have Rb/Cs > 120, but unexceptional 208Pb/206Pb and hence κPb values. These samples have experienced U and Cs loss and are excluded from further consideration. Of the unaltered samples, all have (238U/232Th) generally lower than OIB, with maximum values of < 0.8, and some < 0.6. The maximum (230Th/238U) is 1.39, similar to OIB. Although none of the basalts has a primary composition, (230Th/238U) does not vary systematically with indices of fractionation, and comparison with evolved rocks from Kenya indicates that 238U–230Th disequilibrium in the basalts is not the product of fractionation and crustal residence, but a product of melt generation. The maximum (230Th/238U) that can be generated by batch melting, assuming a source mineralogy consistent with the REE variation is 1.05 and so the variation in (230Th/238U) is attributed to more complex models of melt generation and/or transport. Both dynamic melting and equilibrium porous flow suggest mantle upwelling rates of ≤ 2 cm year− 1. It is suggested that the Kenya basalts represent melts derived from lithospheric mantle that has been thermally reactivated by and incorporated into the underlying (East African) mantle plume
Occurrence, contamination evaluation and health risks of trace metals within soil, sediments and tailings in southern Tunisia
The current study highlights the impacts of mining and ore processing activities on the environment and human health in a south Mediterranean area of southern Tunisia. A geochemical characterization was achieved by analyzing urban soil, stream sediments, mine wastes (tailings, sludge) and phosphate ore, for trace metals "TM" (Cd, Cr, Zn, Mn) have revealed that the samples are highly enriched with metals. An evaluation of the contamination status was attained by calculating pollution indices. Results showed that samples are ranging between moderately and very strongly polluted with TM. Human health risk was evaluated by calculating hazard quotient (HQ), total non-carcinogenic risk (NCR) expressed as hazard index (HI) and carcinogenic risk (CR). The non-carcinogenic risk (NCR) did not exceed the established threshold (NCR > 1) in all studied cases (age or gender based). Thus, local residents of the study area are likely far from developing non-carcinogenic diseases arising from TM exposure. Conversely, CR did exceed the proposed standards (CR > 10(-4)) in some cases. Accordingly, there is a carcinogenic risk associated with children's exposure to Cr. Globally, our findings prove that children of Gafsa-Metlaoui mining area are more vulnerable to TM contamination than adults could develop health complications. To a lesser extent, females are also more vulnerable than males in the concerned area. In order to eliminate any potential health risks, waste management's legislation should be established in Tunisia and similar areas worldwide (open cast-mining, abandoned mine sites, etc.) to control and mitigate the effects of mining and industrial activities on the environment and the human health
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