Miracle-dz/UniFAR-FTUs huggingface dataset:
Cobalt ions induce chemokine secretion in primary human osteoblasts

Chemokines are major regulators of the inflammatory response and have been shown to play an important role in periprosthetic osteolysis. Titanium particles have previously been shown to induce IL‐8 and MCP‐1 secretion in osteoblasts. These chemokines result in the chemotaxis and activation of neutrophils and macrophages, respectively. Despite a resurgence in the use of cobalt‐chromium‐molybdenum alloys in metal‐on‐metal arthroplasty, cobalt and chromium ion toxicity in the periprosthetic area has been insufficiently studied. In this study we investigate the in vitro effect of cobalt ions on primary human osteoblast activity. We demonstrate that cobalt ions rapidly induce the protein secretion of IL‐8 and MCP‐1 in primary human osteoblasts. This elevated chemokine secretion is preceded by an increase in the transcription of the corresponding chemokine gene. Using a Transwell migration chemotaxis assay we also demonstrate that the chemokines secreted are capable of inducing neutrophil and macrophage migration. Furthermore, cobalt ions significantly inhibit osteoblast function as demonstrated by reduced alkaline phosphatase activity and calcium deposition. In aggregate these data demonstrate that cobalt ions can activate transcription of the chemokine genes IL‐8 and MCP‐1 in primary human osteoblasts. Cobalt ions are not benign and may play an important role in the pathogenesis of osteolysis by suppressing osteoblast function and stimulating the production and secretion of chemokines that attract inflammatory and osteoclastic cells to the periprosthetic area. © 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 27: 855–864, 2009
Psychological Contracts and Job Satisfaction: Clustering Analysis using Evidential C-Means and Comparison with Other Techniques

The psychological contract refers to an individual employee's belief in mutual obligations between them and their employer. Psychological contracts are a key management concern, as they can impact employees' attitudes and behaviors in ways that influence organizational efficiency and effectiveness. In this paper, we analyse the relationship between the psychological contract and facets of job satisfaction among non-profit sector employees, using the nascent non-hierarchical evidential c-means (ECM) clustering technique. To date, this technique has been theoretically discussed but not widely applied. Based on the Dempster–Shafer theory of evidence, ECM is novel in facilitating the assignment of objects, not only to single clusters, but to sets of clusters, and no clusters (outliers). The paper compares the theoretical underpinnings and findings from ECM with those of three other well-known clustering techniques, namely (1) the hierarchical Ward's method, (2) the non-hierarchical crisp k-means and (3) the non-hierarchical fuzzy c-means approaches. We present and interpret the cluster solutions from each clustering technique. We establish three clusters differentiated by the content of the employees' psychological contracts. These clusters are validated by considering their relationship with facets of job satisfaction, to ensure the clusters are theoretically meaningful. Comparisons of the findings from each technique: (1) provide insights into the relationship between the psychological contract and job satisfaction; (2) reveal what ECM encompasses, relative to other clustering techniques; (3) inform the selection of an appropriate clustering technique for a specific research problem; and (4) demonstrate potential future directions in the development of cluster analysis. Copyright © 2012 John Wiley & Sons, Ltd.
FACTORS INFLUENCING MOBILE-LEARNING ADOPTION INTENTION: AN EMPIRICAL INVESTIGATION IN HIGH EDUCATION

This study investigates the use of mobile phones and tablets for learning purposes among university students in Vietnam. For this purpose, the research is based on relevant technology acceptance literature and the Technology Acceptance Model (TAM) is proposed to analyze the adoption of mobile devices and smart phones by Vietnam students for accessing course materials, searching the web for information related to their discipline, sharing knowledge, conducting assignments etc. Employing structural equation modeling (SEM) technology, the model was assessed based on the data collected from 301 participants using a survey questionnaire. These results validate the power of TAM constructs and its appropriateness for predicting acceptance of mobile learning. Usefulness had the highest path coefficients and was a strong predictor of behavioral intention and attitude to use and thus actual use. The proposed TAM model also can improve the understanding of students’ motivation by suggesting what external factors are the most important in enhancing students acceptance of mobile learning.
Electrospun polyimide/organic montmorillonite composite nanofibrous membranes with enhanced mechanical properties and flame retardancy

Polyimide/organic montmorillonite nanofibrous membranes were fabricated through electrospinning of polyamic acid/organic montmorillonite precursors followed by a thermal imidization process. Scanning electron microscopy micrographs showed small amounts of organic montmorillonite addition (<3%) and increase in the diameter of polyimide nanofibers. However, higher organic montmorillonite fraction generated microspheres due to the aggregation of clay nanoplatelets. Transmission electron microscopy images indicated that both exfoliated and intercalated organic montmorillonites existed in polyimide nanofibers when low quantity of clay was loaded (<3%). As the clay amount increased, exfoliated structure disappeared and stacked clay layers were observed. The optimum concentration of organic montmorillonite is 3%. By incorporating 3% clay, the tensile strength and modulus of membrane increased by 92.1 and 48.6%, respectively. Moreover, the limiting oxygen index value arose from 29.2 to 30.4%. Higher thermal stability was also achieved because of the heat barrier effect of clay layers. The onset decomposition temperature increased by 17℃ by adding 5% clay. These results demonstrate that tiny organic montmorillonite incorporation is relatively effective for improving the mechanical properties as well as flame retardancy of polyimide nanofibrous membrane.
Biotribocorrosion of Hard-on-Hard Bearing Surfaces in Orthopaedic Hip Replacements

Following higher than acceptable failure rates, the most recent generation of Metal-on-Metal THRs have all but been removed from the market. Many recent studies in the literature attribute their failure to higher wear rates as a result of so-called ‘adverse loading’ scenarios. In order to investigate the in situ corrosive degradation of 28 mm Metal-on-Metal and Metal-on-Ceramic Total Hip Replacement components under these ‘adverse loading’ scenarios, two hip simulators were instrumented with three-electrode electrochemical cells. Various DC electrochemical analysis techniques, including Linear Polarisation Resistance and Potentiostatic Polarisation, were used to quantify the corrosion currents released from the bearings during sliding. Under 0.8 mm of Microseparation the corrosion currents were found to increase by a near order of magnitude compared to Standard Gait; which resulted in an increase of estimated corrosive volume loss from approximately 0.03 - 0.05 mm3 to as much as 0.24 mm3. A similar increase was observed for Metal-on-Ceramic bearings whereby the contribution of corrosion to total material loss from the bearing shifted from approximately 4 - 8 % to as much as 17 %. Under potentiostatic polarisation the resultant anodic current transient was found to increase with increased angle of acetabular inclination. The magnitude of peak current increased from approximately 5 - 10 µA at 30° inclination to 80 - 120 µA at 50°. Corrosion at the bearing surface of 28 mm Total Hip Components was found to be a significant source of corrosive material loss and ion release. This was also sensititve to the articulations conditions and did not necessarily scale linearly with total mass loss. Consideration of the mechanisms of degradation is therefore critical to pre-clinical assessment of devices in order to better predict in vivo performance.
Association of a microRNA/TP53 feedback circuitry with pathogenesis and outcome of B-cell chronic lymphocytic leukemia.

CONTEXT Chromosomal abnormalities (namely 13q, 17p, and 11q deletions) have prognostic implications and are recurrent in chronic lymphocytic leukemia (CLL), suggesting that they are involved in a common pathogenetic pathway; however, the molecular mechanism through which chromosomal abnormalities affect the pathogenesis and outcome of CLL is unknown. OBJECTIVE To determine whether the microRNA miR-15a/miR-16-1 cluster (located at 13q), tumor protein p53 (TP53, located at 17p), and miR-34b/miR-34c cluster (located at 11q) are linked in a molecular pathway that explains the pathogenetic and prognostic implications (indolent vs aggressive form) of recurrent 13q, 17p, and 11q deletions in CLL. DESIGN, SETTING, AND PATIENTS CLL Research Consortium institutions provided blood samples from untreated patients (n = 206) diagnosed with B-cell CLL between January 2000 and April 2008. All samples were evaluated for the occurrence of cytogenetic abnormalities as well as the expression levels of the miR-15a/miR-16-1 cluster, miR-34b/miR-34c cluster, TP53, and zeta-chain (TCR)-associated protein kinase 70 kDa (ZAP70), a surrogate prognostic marker of CLL. The functional relationship between these genes was studied using in vitro gain- and loss-of-function experiments in cell lines and primary samples and was validated in a separate cohort of primary CLL samples. MAIN OUTCOME MEASURES Cytogenetic abnormalities; expression levels of the miR-15a/miR-16-1 cluster, miR-34 family, TP53 gene, downstream effectors cyclin-dependent kinase inhibitor 1A (p21, Cip1) (CDKN1A) and B-cell CLL/lymphoma 2 binding component 3 (BBC3), and ZAP70 gene; genetic interactions detected by chromatin immunoprecipitation. RESULTS In CLLs with 13q deletions the miR-15a/miR-16-1 cluster directly targeted TP53 (mean luciferase activity for miR-15a vs scrambled control, 0.68 relative light units (RLU) [95% confidence interval {CI}, 0.63-0.73]; P = . 02; mean for miR-16 vs scrambled control, 0.62 RLU [95% CI, 0.59-0.65]; P = . 02) and its downstream effectors. In leukemic cell lines and primary CLL cells, TP53 stimulated the transcription of miR-15/miR-16-1 as well as miR-34b/miR-34c clusters, and the miR-34b/miR-34c cluster directly targeted the ZAP70 kinase (mean luciferase activity for miR-34a vs scrambled control, 0.33 RLU [95% CI, 0.30-0.36]; P = .02; mean for miR-34b vs scrambled control, 0.31 RLU [95% CI, 0.30-0.32]; P = .01; and mean for miR-34c vs scrambled control, 0.35 RLU [95% CI, 0.33-0.37]; P = .02). CONCLUSIONS A microRNA/TP53 feedback circuitry is associated with CLL pathogenesis and outcome. This mechanism provides a novel pathogenetic model for the association of 13q deletions with the indolent form of CLL that involves microRNAs, TP53, and ZAP70.
A conversation with Margaret Becklake.

Margaret Becklake was born in 1922 and grew up in Pretoria, South Africa. She trained in medicine at the University of the Witwaterstrand, Johannesburg, graduated with MB and BCh degrees in 1944, and then interned at the Johannesburg General Hospital. This was followed by postgraduate studies at what was then the British Postgraduate Medical School, Hammersmith, London, U.K., where she focused on respiratory function. On her return to Johannesburg in 1950, she was appointed a Junior Lecturer in Medicine at her alma mater and also Respiratory Physiologist to the Pneumoconiosis Bureau in Johannesburg. There she carried out her first epidemiologic studies, including the documentation of lung function in subjects living 1 mile above sea level, and of the effects of mine dust exposure and silicosis on lung function in Witwaterstrand gold miners. In 1957, she moved to Montreal, Canada, and worked in the Lung Function Laboratory of the Department of Medicine, Royal Victoria Hospital. In 1967, she set up a lung function laboratory in support of Professor Corbett McDonald’s research program into the effects of exposure to asbestos in the chrysotile miners and millers of Québec. She was the recipient of a Medical Research Council of Canada Career Investigator award from 1968 to 1993. She is currently an Emeritus Professor at McGill University, with appointments in the Department of Epidemiology and Biostatistics and the Department of Medicine, as well as in the Respiratory Epidemiology and Clinical Research Unit of the Montreal Chest Institute and the Meakins Christie Laboratories.
Identification of a novel component C2ORF3 in the lariat–intron complex: lack of C2ORF3 interferes with pre‐mRNA splicing via intron turnover pathway

To identify the novel factors involved in the postsplicing intron turnover pathway, we carried out immunoprecipitation with known postsplicing factors, hPrp43 and TFIP11. As an interacting factor, we identified C2ORF3 protein by mass spectrometry. We found that C2ORF3 protein is present in the previously characterized Intron Large (IL) complex with an excised lariat intron. In vitro splicing using C2ORF3‐depleted nuclear extracts showed significant repression of splicing, suggesting that C2ORF3 protein is required for pre‐mRNA splicing through its presumable role in efficient intron turnover. Interestingly, C2ORF3 protein is localized in both the nucleoplasm and nucleoli, which suggests a potential function in rRNA processing.
Predictors of the evolution of microalbuminuria.

Albuminuria, either micro- or macro-, is considered as an independent cardiovascular and renal risk factor that must be determined in any patient with diabetes and with arterial hypertension. The presence of microalbuminuria has also been shown to be a risk factor of similar magnitude in the general population,1 although the possibility of its estimation in the whole population remains as an elusive objective. Recently, 2 relevant issues related to albuminuria have been published: first, prevention of development of microalbuminuria has been demonstrated as an attainable objective in type 2 diabetic patients2 and, second, diminution of the urinary excretion of albumin has been shown to be followed by a significant decrease in the development of cardiovascular events and death.3 All of these facts enhance the need to improve our knowledge on predictors of the development and evolution of microalbuminuria. Further progression to macroalbuminuria occurs in a significant number of cases, particularly, but not solely, in diabetic patients, indicating the presence of overt renal disease. Such a progression can be seen in nondiabetic patients with arterial hypertension4 and also in patients with advanced cardiovascular disease.5 The present issue of Hypertension contains a …
On the usefulness of higher-order disturbance observers in real control scenarios based on perturbation estimation and mitigation

In this paper, a technique of increasing the effectiveness of estimating the overall system uncertainty with a class of high-gain disturbance observers is discussed. In theory, by introducing a particular set of additional, fictitious states to the system model, the considered observers can more effectively estimate wider variety of disturbances than in their classical forms. This work describes the verification of such theoretical statement also in practice. Both advantages and disadvantages of the proposed framework are pointed out in the paper using an Extended State Observer (ESO), that serves as an working example. An evaluation of the considered technique is carried out through a combination of numerical simulations and laboratory experiments.
Repeated Low-Dose Influenza Virus Infection Causes Severe Disease in Mice: a Model for Vaccine Evaluation

ABSTRACT Influenza infection causes severe disease and death in humans. In traditional vaccine research and development, a single high-dose virus challenge of animals is used to evaluate vaccine efficacy. This type of challenge model may have limitations. In the present study, we developed a novel challenge model by infecting mice repeatedly in short intervals with low doses of influenza A virus. Our results show that compared to a single high-dose infection, mice that received repeated low-dose challenges showed earlier morbidity and mortality and more severe disease. They developed higher vial loads, more severe lung pathology, and greater inflammatory responses and generated only limited influenza A virus-specific B and T cell responses. A commercial trivalent influenza vaccine protected mice against a single high and lethal dose of influenza A virus but was ineffective against repeated low-dose virus challenges. Overall, our data show that the repeated low-dose influenza A virus infection mouse model is more stringent and may thus be more suitable to select for highly efficacious influenza vaccines. IMPORTANCE Influenza epidemics and pandemics pose serious threats to public health. Animal models are crucial for evaluating the efficacy of influenza vaccines. Traditional models based on a single high-dose virus challenge may have limitations. Here, we describe a new mouse model based on repeated low-dose influenza A virus challenges given within a short period. Repeated low-dose challenges caused more severe disease in mice, associated with higher viral loads and increased lung inflammation and reduced influenza A virus-specific B and T cell responses. A commercial influenza vaccine that was shown to protect mice from high-dose challenge was ineffective against repeated low-dose challenges. Overall, our results show that the low-dose repeated-challenge model is more stringent and may therefore be better suited for preclinical vaccine efficacy studies.
Additional value of combining low-dose computed tomography to V/Q SPECT on a hybrid SPECT-CT camera for pulmonary embolism diagnosis

ObjectivesThe aim of the study was to assess the potential interest of combining a low-dose computed tomography (ldCT) to ventilation/perfusion (V/Q) single-photon emission computed tomography (SPECT) for the diagnosis of pulmonary embolism (PE). We addressed three main questions: Could ldCT be used in substitution to ventilation SPECT? Could ldCT improve the diagnostic performance of V/Q SPECT? Could ldCT provide alternative diagnoses to PE? MethodsA total of 393 patients previously analysed in a management outcome study that aimed at assessing the safety of V/Q SPECT for PE diagnosis were assessed. All patients underwent an ldCT under the same SPECT-computed tomography camera, which was not used at the time of initial interpretation. Three retrospective analyses were performed: Q SPECT combined with ldCT, V/Q SPECT combined with ldCT and ldCT only. ResultsOn the basis of initial V/Q SPECT interpretation, 110 (28%) patients were positive and 283 (72%) were negative for PE.With Q SPECT-ldCT, 139 (35%) patients were positive and 254 (65%) were negative, with 55 (19%) discrepancies when compared with V/Q SPECT. Of the 283 patients with negative V/Q SPECT, 42 were positive with V/Q SPECT-ldCT, and among the 110 patients with positive V/Q SPECT 13 were negative with V/Q SPECT-ldCT. On using V/Q SPECT-ldCT, 97 (25%) patients were positive and 296 (75%) were negative, with 13 (3%) discrepancies when compared with V/Q SPECT (all had had a positive V/Q SPECT but a negative V/Q SPECT-ldCT). Finally, 67 (24%) ldCT scans showed a potential alternative diagnosis to PE. ConclusionFor PE diagnosis with lung SPECT, the use of ldCT in substitution to ventilation SPECT is associated with a high risk of overdiagnosis. The diagnostic value of ldCT in addition to V/Q SPECT remains unclear. Further studies are needed to determine its potential role in PE diagnosis.
PRIME: Peer-to-Peer Receiver-drIven MEsh-Based Streaming

The success of swarming content delivery has motivated a new approach to live peer-to-peer (P2P) streaming that we call mesh-based streaming. In this approach, participating peers form a random mesh and incorporate swarming content delivery to stream live content. Despite the growing popularity of this approach, neither the design tradeoffs nor the basic performance bottlenecks in mesh-based P2P streaming are well understood. This paper presents PRIME, the first mesh-based P2P streaming for live content that effectively incorporates swarming content delivery. We identify two performance bottlenecks in a mesh-based P2P streaming, namely bandwidth bottleneck and content bottleneck. We derive proper peer connectivity to minimize bandwidth bottleneck as well as an efficient pattern of delivery for live content over a random mesh to minimize content bottleneck. We show that the pattern of delivery can be divided into diffusion and swarming phases and then identify proper packet scheduling algorithm at individual peers. Using ns simulations, we examine key characteristics, design tradeoffs and the relationship between main system parameters.
Treatment of acromegaly by endoscopic transsphenoidal surgery: surgical experience in 214 cases and cure rates according to current consensus criteria.

OBJECT Acromegaly is a disease that has significant morbidity and mortality related to high levels of growth hormone (GH) and insulin-like growth factor-I (IGF-I), and is usually caused by pituitary adenomas. The goal in this study was to investigate the role of endoscopic transsphenoidal surgery and surgical experience in the treatment of GH adenoma cases in relation to surgical results and hormonal cure rates, and to perform a review of the literature. METHODS The authors present a retrospective analysis of 214 GH adenoma cases. Restoration of IGF-I levels to normal for age and sex, suppression of GH levels below 0.4 μg/L on the oral glucose tolerance test, and demonstration of the total removal of the tumor on MRI studies obtained after administration of contrast material at the 3-month postoperative follow-up visit were the criteria for cure. RESULTS In total 214 patients with a mean age of 41.9 ± 12 years (range 17-75 years) and a male/female ratio of 106/108 were enrolled in the study. Cure was achieved in 134 (62.6%) of 214 patients. One hundred sixty-nine patients were primary cases, and of these 109 (64.5%) were cured, whereas 61 patients were previously operated cases and of these 25 (41%) were cured. With a 51.1% decrease in the 1st month postoperatively, IGF-I levels were found to be predictive of cure (74.4% sensitivity and 73.7% specificity). Cut-off values for GH levels in predicting cure for the 1st day, 1st week, and 1st month postoperatively were 2.33, 2.05, and 2.25 μg/L, respectively. The cut-off value for surgical experience was 57 for primary surgeries (58.5% cure rate before this cut-off value compared with 72.6% after it; p = 0.025) and 108 for all operations (45.8% vs. 79.4%, p = 0.037). Although 28 patients were found to be in remission according to the criteria in 2000, they were not in remission according to the new consensus criteria. Nine of these cases (32.1%) had random GH levels < 1 μg/L at the 1-year follow-up. The 1-year IGF-I and GH levels in these 28 patients showed no significant difference when compared with the cases defined as cured according to the current criteria. CONCLUSIONS In acromegaly treatment, transsphenoidal endoscopic surgery performed by an expert senior surgeon and increased surgical experience are important for higher cure rates. Random GH levels < 2.33 μg/L after the 1st day postoperatively and a > 50% decrease in IGF-I levels after the 1st month postoperatively are predictive of cure. Moreover, there is no urgency for additional therapy in patients with GH levels of 0.4-1 μg/L and MRI sequences showing no tumor at the 3-month follow-up, because for these cases remission can be achieved at the 1-year follow-up.