30 research outputs found

    Down-regulation of miR-133a and miR-539 are associated with unfavorable prognosis in patients suffering from osteosarcoma

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    Background: MicroRNAs (miRNAs) play key roles in cancer development and progression. The purpose of the present study was to determine the expression levels of miR-133a and miR-539 in osteosarcoma patients and to further investigate the clinicopathological, and prognostic value of these miRNAs. Methods: The expression levels of miR-133a and miR-539 were determined by qRT-PCR. Associations between miRNAs expressions and various clinicopathological characteristics were analyzed. Survival rate was determined with Kaplan-Meier and statistically analyzed with the log-rank method between groups. Survival data were evaluated through multivariate Cox regression analysis Results: Our findings revealed that the miR-133a expression was significantly decreased in clinical osteosarcoma tissues compared to adjacent normal bone tissues. The expression level of miR-539 was decreased in clinical osteosarcoma tissues as compared to those adjacent normal tissues. Low expressions of miR-133a and miR-539 were significantly association with advanced TNM stage (P=0.002; P=0.001), and metastasis or recurrence (P=0.001; P=0.01). Furthermore, Kaplan-Meier survival analysis and log-rank test showed that the low expressions of miR-133a and miR-539 were correlated with the reduced overall survival of osteosarcoma patients. Multivariate Cox proportional hazards model showed that decreased expressions of miR-133a and miR-539 (P=0.007; P=0.02), TNM stage (P=0.001; P=0.002), and metastasis or recurrence (P=0.005; P=0.026) were independent prognostic markers of overall survival of patients. Conclusion: These results suggest that decreased miR-133a and miR-539 expressions may participate in the progression of osteosarcoma. Together, these results showed that miR-133a and miR-539 may have their role in both progression and prognosis of osteosarcoma. © 2015 Mirghasemi et al

    Stress-strain behavior and geometrical properties of packings of elongated particles

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    We present a numerical analysis of the effect of particle elongation on the quasistatic behavior of sheared granular media by means of the Contact Dynamics method. The particle shapes are rounded-cap rectangles characterized by their elongation. The macroscopic and microstructural properties of several packings subjected to biaxial compression are analyzed as a function of particle elongation. We find that the shear strength is an increasing linear function of elongation. Performing an additive decomposition of the stress tensor based on a harmonic approximation of the angular dependence of branch vectors, contact normals and forces, we show that the increasing mobilization of friction force and the associated anisotropy are key effects of particle elongation. These effects are correlated with partial nematic ordering of the particles which tend to be oriented perpendicular to the major principal stress direction and form side-to-side contacts. However, the force transmission is found to be mainly guided by cap-to-side contacts, which represent the largest fraction of contacts for the most elongated particles. Another interesting finding is that, in contrast to shear strength, the solid fraction first increases with particle elongation, but declines as the particles become more elongated. It is also remarkable that the coordination number does not follow this trend so that the packings of more elongated particles are looser but more strongly connected.Comment: Submited to Physical Review

    Tissue expression levels of miR-29b and miR-422a in children, adolescents, and young adults� age groups and their association with prediction of poor prognosis in human osteosarcoma

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    Osteosarcoma is the most common type of bone cancer in children and adolescents. MicroRNAs (miRNAs) play important roles in the development, differentiation, and function of different cell types and in the pathogenesis of various human diseases. miRNAs are differentially expressed in normal and cancer cells. The investigation of miRNA expression between healthy subjects and patients with osteosarcoma is crucial for future clinical trials. In this study, the expression levels of miRNAs were detected by qRT-PCR. Correlation between expression levels of tow miRNAs and different clinicopathological characteristics were analyzed using the �2 test. Survival rate was detected using the log-rank test and Kaplan�Meier method. qRT-PCR was shown that expression levels of miR-29b and miR-422a were strongly decreased in osteosarcoma bone tissue compared with noncancerous bone tissues. Our result indicated that the low expression levels of miR-29b and miR-422a showed strong correlation with large tumor size (P = 0.20; 0.029), advanced TNM stage (P = 0.001; 0.012), distant metastasis (P = 0.008; 0.019), and grade of tumor (P = 0.009; 0.016). Kaplan�Meier survival analysis showed that the low expressions of miR-29b/miR-422a were correlated with shorter time overall survival (log-rank test, P = 0.009; P = 0.013). Moreover, multivariate Cox proportional hazards model indicated that miR-29b and miR-422a (P = 0.024; P = 0.016) were independent prognostic markers of overall survival of patients. Our result indicated that downregulation of miR-29b and miR-422a may be linked to the prediction of poor prognosis, indicating that miR-29b and miR-422a may be a valuable prognostic marker for osteosarcoma patients. © 2015, International Society of Oncology and BioMarkers (ISOBM)

    Retraction Note to: Tissue expression levels of miR-29b and miR-422a in children, adolescents, and young adults� age groups and their association with prediction of poor prognosis in human osteosarcoma (Tumor Biol, (2016), 37, (3091-3095), 10.1007/s13277-015-4140-5)

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    This article has been retracted at the request of the Editorin- Chief, the International Society of Oncology and BioMarkers (ISOBM) and the Publisher per the Committee on Publication Ethics guidelines. The article shows evidence of irregularities in authorship, there is strong reason to believe that the peer review process was compromised and the article is showing similarities with the following article which was submitted within a close timeframe: Seyad Alireza Bassampour, Reza Abdi, Reza Bahador, Mohammadreza Shakeri, Ali Torkaman, Emad Yahaghi, Afshin Taheriazam, Downregulation of miR-133b/miR-503 acts as efficient prognostic and diagnostic factors in patients with osteosarcoma and these predictor biomarkers are correlated with overall survival. Tumor Biol. First online: 16 August 2015 DOI: 10.1007/s13277-015-3918-9. © 2016, International Society of Oncology and BioMarkers (ISOBM)

    Retraction to: Down-regulation of miR-133a and miR-539 are associated with unfavorable prognosis in patients suffering from osteosarcoma Cancer Cell Int, 15, (2015), (86) DOI 10.1186/s12935-015-0237-6

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    The Editors-in-Chief and Publisher have retracted this article 1 because the scientific integrity of the content cannot be guaranteed. An investigation by the Publisher found it to be one of a group of articles we have identified as showing evidence suggestive of attempts to subvert the peer review and publication system to inappropriately obtain or allocate authorship. This article showed evidence of plagiarism (most notably from the articles cited 2, 3) and authorship manipulation. © The Author(s) 2016

    Strengthening livelihood resilience in upper catchments of dry areas by integrated natural resources management

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    The Livelihood Resilience project evolved around the hypothesis that better integrated management can improve the livelihoods of poor farming communities and increase the environmental integrity and water productivity of upstream watersheds in dry areas. This hypothesis was tested by researchers from different Iranian research and executive organizations and farming communities in two benchmark research watersheds in upper Karkheh River Basin in Iran, under the guidance of the ICARDA scientists. Participatory technology development, water, soil, erosion, land degradation and vegetation assessments, livelihood, gender and policy analyses, and integrated workshops delivered a set of principles for watershed management in dry areas

    Construction and performance of the Karkheh Dam Complementary Cut-off Wall: an innovative engineering solution

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    Construction of a dam cut-off wall is one of the most challenging tasks in dam engineering given the deep excavations involved and the complex interactions between stiff cut-off walls and soft surrounding soils. Here, we present innovative solutions for the development of the Karkheh dam’s complementary cut-off wall in southwest Iran which is among the largest structures of this type worldwide with a maximum depth of 115 m. Due to excessive water seepage and high hydraulic gradient following the reservoir impoundment, additional measures were considered among which was the extension of the existing cut-off wall. The main goal was to decrease the hydraulic gradient of the seepage through the dam foundation. The construction of this new wall, which is called as the complementary wall here, was associated with a number of technical challenges among which were: the connection between the new and old walls; trenching and placing of plastic concrete wall through different dam body zones; and slurry loss during trenching through the dam body zones. The complementary wall was constructed successfully producing invaluable engineering experiences including: design of a U-shaped panel as the connecting panel; design of a new method for grouting through uniformly distributed filter/drain materials; and adding cement-based grouts to the cut-off wall panels to prevent slurry loss. The complementary wall helped to decrease both total seepage and the hydraulic gradient; for instance, in the right abutment, total seepage was cut for 25% and the hydraulic gradient was reduced from 0.2 to 0.095

    A laboratory-numerical approach for modelling scale effects in dry granular slides

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    Granular slides are omnipresent in both natural and industrial contexts. Scale effects are changes in physical behaviour of a phenomenon at different geometric scales, such as between a laboratory experiment and a corresponding larger event observed in nature. These scale effects can be significant and can render models of small size inaccurate by underpredicting key characteristics such as ow velocity or runout distance. Although scale effects are highly relevant to granular slides due to the multiplicity of length and time scales in the flow, they are currently not well understood. A laboratory setup under Froude similarity has been developed, allowing dry granular slides to be investigated at a variety of scales, with a channel width configurable between 0.25-1.00 m. Maximum estimated grain Reynolds numbers, which quantify whether the drag force between a particle and the surrounding air act in a turbulent or viscous manner, are found in the range 102-103. A discrete element method (DEM) simulation has also been developed, validated against an axisymmetric column collapse and a granular slide experiment of Hutter and Koch (1995), before being used to model the present laboratory experiments and to examine a granular slide of significantly larger scale. This article discusses the details of this laboratory-numerical approach, with the main aim of examining scale effects related to the grain Reynolds number. Increasing dust formation with increasing scale may also exert influence on laboratory experiments. Overall, significant scale effects have been identified for characteristics such as ow velocity and runout distance in the physical experiments. While the numerical modelling shows good general agreement at the medium scale, it does not capture differences in behaviour seen at the smaller scale, highlighting the importance of physical models in capturing these scale effects

    On the Capacity of the One-Bit Deletion and Duplication Channel

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