119 research outputs found

    Valence change of praseodymium in Pr0.5Ca0.5CoO3 investigated by x-ray absorption spectroscopy

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    X-ray absorption spectroscopy measurements in Pr0.5Ca0.5CoO3 were performed at the Pr M4,5, Pr L3, and Ca L2,3 absorption edges as a function of temperature below 300 K. Ca spectra show no changes down to 10 K while a noticeable thermally dependent evolution takes place at the Pr edges across the metal-insulator transition. Spectral changes are analyzed by different methods, including multiple scattering simulations, which provide quantitative details on an electron loss at Pr 4f orbitals. We conclude that in the insulating phase a fraction [15(+5)%] of Pr3+ undergoes a further oxidation to adopt a hybridized configuration composed of an admixture of atomic-like 4f1 states (Pr4+) and f- symmetry states on the O 2p valence band (Pr3+L states) indicative of a strong 4f- 2p interaction.Comment: 19 pages (.doc), 4 figures, Phys. Rev. B, in pres

    Loot box purchases and their relationship with internet gaming disorder and online gambling disorder in adolescents: a prospective study

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    In recent years, the video game industry has introduced Loot Box (LB), a new type of microtransaction in which a gamer uses real currency to purchase a random virtual item within a video game. Recently, LBs became more widespread and there is evidence suggesting their similarity to online gambling. Although some studies have investigated the association between LBs with disordered gaming and disordered gambling, very few have done so with clinical indicators of these problems. Furthermore, to the best of our knowledge no longitudinal evidence of such relationships currently exists in the literature. Therefore, the present study aimed to 1) ascertain the stability of LB purchasing in minors and 2) investigate the associations between LB purchasing with gambling online and online gambling disorder within six months. A prospective cohort study was conducted at two time points six months apart. In total, 2.213 Spanish adolescents (1.067 [48.9%] boys) aged between 11 and 17 years participated in both waves. The purchase of LBs was prevalent and stable in the sample across the six months. While a positive relationship was found between purchasing LBs and online gambling six months later, the relationships between purchasing LBs and the presentation of online gambling disorder and gaming disorder require further study

    Apex scavengers from different European populations converge at threatened savannah landscapes

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    Over millennia, human intervention has transformed European habitats mainly through extensive livestock grazing. “Dehesas/Montados” are an Iberian savannah-like ecosystem dominated by oak-trees, bushes and grass species that are subject to agricultural and extensive livestock uses. They are a good example of how large-scale, low intensive transformations can maintain high biodiversity levels as well as socio-economic and cultural values. However, the role that these human-modified habitats can play for individuals or species living beyond their borders is unknown. Here, using a dataset of 106 adult GPS-tagged Eurasian griffon vultures (Gyps fulvus) monitored over seven years, we show how individuals breeding in western European populations from Northern, Central, and Southern Spain, and Southern France made long-range forays (LRFs) of up to 800 km to converge in the threatened Iberian “dehesas” to forage. There, extensive livestock and wild ungulates provide large amounts of carcasses, which are available to scavengers from traditional exploitations and rewilding processes. Our results highlight that maintaining Iberian “dehesas” is critical not only for local biodiversity but also for long-term conservation and the ecosystem services provided by avian scavengers across the continent

    Phase II randomised trial of raltitrexed–oxaliplatin vs raltitrexed–irinotecan as first-line treatment in advanced colorectal cancer

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    The purpose of this phase II randomised trial was to determine which of two schemes, raltitrexed-irinotecan or raltitrexed-oxaliplatin, offered better activity and less toxicity in patients with advanced colorectal cancer (CRC). A total of 94 patients with previously untreated metastatic CRC were included and randomised to receive raltitrexed 3 mg m−2 followed by oxaliplatin 130 mg m−2 on day 1 (arm A), or CPT-11 350 mg m−2 followed by raltitrexed 3 mg m−2 (arm B). In both arms treatment was repeated every 3 weeks. Intent-to-treat (ITT) analysis showed an overall response rate of 46% (95% CI, 29.5–57.7%) for arm A, and 34% (95% CI, 19.8–48.4%) for arm B. Median time to progression was 8.2 months for arm A and 8.8 months for arm B. After a median follow-up of 14 months, 69% of patients included in arm A were still alive, compared to 59% of those included in arm B. Overall, 31 patients (65%) experienced some episode of toxicity in arm A and 32 patients (70%) in arm B, usually grade 1–2. The most common toxicity was hepatic, with 29 patients (60%) in arm A and 24 patients (62%) in arm B, and was grade 3–4 in four (8%) and four (9%) patients, respectively. In all, 14 patients (29%) from arm A and 24 patients (52%) from arm B had some grade of diarrhoea (P<0.03). Neurologic toxicity was observed in 31 patients (64%) in arm A, and was grade 3–4 in five patients (10%), while a cholinergic syndrome was detected in nine patients (19%) in arm B. There were no differences in haematologic toxicity. One toxic death (2%) occurred in arm A and three (6.5%) in arm B. In conclusion, both schemes have high efficacy as first-line treatment in metastatic CRC and their total toxicity levels are similar. Regimens with raltitrexed seem a reasonable alternative to fluoropyrimidines

    Capecitabine and bevacizumab as first-line treatment in elderly patients with metastatic colorectal cancer

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    BACKGROUND: The efficacy and safety of capecitabine and bevacizumab in elderly patients with metastatic colorectal cancer (mCRC) considered unsuitable for receiving first-line chemotherapy with an irinotecan or oxaliplatin-based combination were assessed in a phase II, open, multicentre, uncontrolled study. METHODS: Treatment consisted of capecitabine 1250 mgm 2 (or 950 mgm 2 for patients with a creatinine clearance of 30–50ml min 1) twice daily on days 1–14 and bevacizumab (7.5 mg kg 1) on day 1 every 3 weeks. RESULTS: A total of 59 patients aged X70 years with mCRC were enrolled. In an intention-to-treat analysis, the overall response rate was 34%, with 71% of patients achieving disease control. Median progression-free survival and overall survival were 10.8 months and 18 months, respectively. In all, 32 patients (54%) had grade 3/4 adverse events (AEs), the most common being hand–foot syndrome (19%), diarrhoea (9%) and deep venous thrombosis (7%). Four patients died because of treatment-related AEs. A relationship was detected between creatinine clearance p50 ml min 1 and the development of non-bevacizumab-related grade 3/4 AEs. The incidence of bevacizumab-associated AEs (hypertension, thromboembolic events and proteinuria) was consistent with that of previous reports in elderly patients. CONCLUSION: Bevacizumab combined with capecitabine represents a valid therapeutic alternative in elderly patients considered to be unsuitable for receiving polychemotherapy.This study was supported by Hoffmann-La Roche, Nutley, NJ, USA

    Why ‘Good Governance’ Fails: Lessons from Regional Economic Development in Colombia

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    By critically reviewing different strands of literature on institutional change and development, this essay argues that, in order to fully understand subnational economic development, we need to move away from ‘good governance' explanations in which geography‐specific analyses of power structures and elite interests are largely absent. Using findings for Colombia and insights from economic geography and heterodox political economy theories, this essay gives theoretical and conceptual guidelines and approximations for future studies on regional economic development. The contribution provides a place‐based discussion of how the historically evolved distribution of power balances, context‐specific elite interests, and the interaction between place‐bound actors and place‐less dynamics affect subnational institutional arrangements shaping policies and development outcomes. The conclusions drawn are not limited to Colombia and will prove beneficial to researchers studying regional economic development in subnational contexts elsewhere in the world

    MALDI Profiling of Human Lung Cancer Subtypes

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    Proteomics is expected to play a key role in cancer biomarker discovery. Although it has become feasible to rapidly analyze proteins from crude cell extracts using mass spectrometry, complex sample composition hampers this type of measurement. Therefore, for effective proteome analysis, it becomes critical to enrich samples for the analytes of interest. Despite that one-third of the proteins in eukaryotic cells are thought to be phosphorylated at some point in their life cycle, only a low percentage of intracellular proteins is phosphorylated at a given time.In this work, we have applied chromatographic phosphopeptide enrichment techniques to reduce the complexity of human clinical samples. A novel method for high-throughput peptide profiling of human tumor samples, using Parallel IMAC and MALDI-TOF MS, is described. We have applied this methodology to analyze human normal and cancer lung samples in the search for new biomarkers. Using a highly reproducible spectral processing algorithm to produce peptide mass profiles with minimal variability across the samples, lineal discriminant-based and decision tree–based classification models were generated. These models can distinguish normal from tumor samples, as well as differentiate the various non–small cell lung cancer histological subtypes.A novel, optimized sample preparation method and a careful data acquisition strategy is described for high-throughput peptide profiling of small amounts of human normal lung and lung cancer samples. We show that the appropriate combination of peptide expression values is able to discriminate normal lung from non-small cell lung cancer samples and among different histological subtypes. Our study does emphasize the great potential of proteomics in the molecular characterization of cancer
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