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1.
Nature ; 507(7491): 221-4, 2014 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-24622201

RESUMO

The ultimate origin of water in the Earth's hydrosphere is in the deep Earth--the mantle. Theory and experiments have shown that although the water storage capacity of olivine-dominated shallow mantle is limited, the Earth's transition zone, at depths between 410 and 660 kilometres, could be a major repository for water, owing to the ability of the higher-pressure polymorphs of olivine--wadsleyite and ringwoodite--to host enough water to comprise up to around 2.5 per cent of their weight. A hydrous transition zone may have a key role in terrestrial magmatism and plate tectonics, yet despite experimental demonstration of the water-bearing capacity of these phases, geophysical probes such as electrical conductivity have provided conflicting results, and the issue of whether the transition zone contains abundant water remains highly controversial. Here we report X-ray diffraction, Raman and infrared spectroscopic data that provide, to our knowledge, the first evidence for the terrestrial occurrence of any higher-pressure polymorph of olivine: we find ringwoodite included in a diamond from Juína, Brazil. The water-rich nature of this inclusion, indicated by infrared absorption, along with the preservation of the ringwoodite, is direct evidence that, at least locally, the transition zone is hydrous, to about 1 weight per cent. The finding also indicates that some kimberlites must have their primary sources in this deep mantle region.

2.
Artigo em Inglês | MEDLINE | ID: mdl-28833865

RESUMO

Guidelines recommend surgery for Stage I-II, chemoradiation for Stage III and systemic therapy for Stage IV non-small cell lung cancer (NSCLC). However, patient related factors and patient preferences influence treatment decisions. We investigated patterns of care for Belgian NSCLC patients in 2010-2011, based on population-based data from the Belgian Cancer Registry and administrative databases. The relationship between patient characteristics, institutional diagnostic volume, type of treatment and survival was investigated. Overall, 20.8% of patients received no oncological treatment. 59% and 22.1% of Stage I-II patients received primary surgery or (chemo)radiation respectively. 34% of Stage III patients received chemoradiation and 17% of Stage IIIA patients had surgery. 70% of Stage IV patients received chemotherapy or targeted therapy. Moderate variability between centres was observed. For Stage IV, systemic therapy was less frequently used in higher volume centres and 1-year survival was lower in centres that had ≥ 50 new patients yearly. Although not all NSCLC patients received treatment as ideally recommended by guidelines, these results do not necessarily represent poor quality of care as patient characteristics and preferences need to be taken into account. Treatment options targeted towards patients with co-morbidity or unfit patients is warranted to improve outcomes of all NSCLC patients.


Assuntos
Adenocarcinoma/terapia , Carcinoma de Células Grandes/terapia , Carcinoma Pulmonar de Células não Pequenas/terapia , Carcinoma de Células Escamosas/terapia , Quimiorradioterapia , Neoplasias Pulmonares/terapia , Pneumonectomia , Padrões de Prática Médica , Adenocarcinoma/patologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Bélgica , Carcinoma de Células Grandes/patologia , Carcinoma Pulmonar de Células não Pequenas/patologia , Carcinoma de Células Escamosas/patologia , Feminino , Fidelidade a Diretrizes , Humanos , Modelos Logísticos , Neoplasias Pulmonares/patologia , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Estadiamento de Neoplasias , Guias de Prática Clínica como Assunto , Modelos de Riscos Proporcionais , Adulto Jovem
3.
Colorectal Dis ; 18(9): 883-8, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27586703

RESUMO

AIM: A fair to moderate concordance in grading of the total mesorectal excision (TME) surgical specimen by local pathologists and a central review panel has been observed in the PROCARE (Project on Cancer of the Rectum) project. The aim of the present study was to evaluate the difference, if any, in the accuracy of predicting the oncological outcome through TME grading by local pathologists or by the review panel. METHOD: The quality of the TME specimen was reviewed for 482 surgical specimens registered on a prospective database between 2006 and 2011. Patients with a Stage IV tumour, with unknown incidence date or without follow-up information were excluded, resulting in a study population of 383 patients. Quality assessment of the specimen was based on three grades including mesorectal resection (MRR), intramesorectal resection (IMR) and muscularis propria resection (MPR). Using univariable Cox regression models, local and review panel histopathological gradings of the quality of TME were assessed as predictors of local recurrence, distant metastasis and disease-free and overall survival. Differences in the predictions between local and review grading were determined. RESULTS: Resection planes were concordant in 215 (56.1%) specimens. Downgrading from MRR to MPR was noted in 23 (6.0%). There were no significant differences in the prediction error between the two models; local and central review TME grading predicted the outcome equally well. CONCLUSION: Any difference in grading of the TME specimen between local histopathologists and the review panel had no significant impact on the prediction of oncological outcome for this patient cohort. Grading of the quality of TME as reported by local histopathologists can therefore be used for outcome analysis. Quality control of TME grading is not warranted provided the histopathologist is adequately trained.


Assuntos
Procedimentos Cirúrgicos do Sistema Digestório , Mesentério/cirurgia , Recidiva Local de Neoplasia/epidemiologia , Neoplasias Retais/cirurgia , Reto/cirurgia , Idoso , Intervalo Livre de Doença , Feminino , Humanos , Masculino , Mesentério/patologia , Pessoa de Meia-Idade , Modelos de Riscos Proporcionais , Neoplasias Retais/mortalidade , Neoplasias Retais/patologia , Reto/patologia , Taxa de Sobrevida , Resultado do Tratamento
4.
Environ Sci Technol ; 46(2): 1178-84, 2012 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-22208159

RESUMO

Recent studies have suggested that exposure of the freshwater invertebrate Daphnia magna to dietary Zn may selectively affect reproduction without an associated increase of whole body bioaccumulation of Zn. The aim of the current research was therefore to investigate the hypothesis that dietary Zn toxicity is the result of selective accumulation in tissues that are directly involved in reproduction. Since under field conditions simultaneous exposure to both waterborne and dietary Zn is likely to occur, it was also tested if accumulation and toxicity under combined waterborne and dietary Zn exposure is the result of interactive effects. To this purpose, D. magna was exposed during a 16-day reproduction assay to Zn following a 5 × 2 factorial design, comprising five waterborne concentrations (12, 65, 137, 207, and 281 µg Zn/L) and two dietary Zn levels (49.6 and 495.9 µg Zn/g dry wt.). Tissue-specific Zn distribution was quantified by synchrotron radiation based confocal X-ray fluorescence (XRF). It was observed that the occurrence of reproductive inhibition due to increasing waterborne Zn exposure (from 65 µg/L to 281 µg/L) was accompanied by a relative increase of the Zn burdens which was similar in all tissues considered (i.e., the carapax, eggs, thoracic appendages with gills and the cluster comprising gut epithelium, storage cells and ovaries). In contrast, the impairment of reproduction during dietary Zn exposure was accompanied by a clearly discernible Zn accumulation in the eggs only (at 65 µg/L of waterborne Zn). During simultaneous exposure, bioaccumulation and toxicity were the result of interaction, which implies that the tissue-specific bioaccumulation and toxicity following dietary Zn exposure are dependent on the Zn concentration in the water. Our findings emphasize that (i) effects of dietary Zn exposure should preferably not be investigated in isolation from waterborne Zn exposure, and that (ii) XRF enabled us to provide possible links between tissue-specific bioaccumulation and reproductive effects of Zn.


Assuntos
Daphnia/efeitos dos fármacos , Daphnia/metabolismo , Poluentes Químicos da Água/toxicidade , Água/química , Zinco/toxicidade , Animais , Dieta , Contaminação de Alimentos , Espectrometria por Raios X , Síncrotrons , Poluentes Químicos da Água/química , Zinco/química
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