1,719 research outputs found

    Identification of the main driving mechanisms in the evolution of a small coastal wetland (Traba, Galicia, NW Spain) since its origin 5700 cal yr BP

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    This paper examines the interdependence among the different forcing factors in the evolution of the Traba coastal wetland (Galicia, NW Spain) based on lithofacies and diatom analyses of three cores reaching the basement. According to radiocarbon data, the wetland originated 5700 cal yr BP, a time when similar systems on the Atlantic coast of the Iberian Peninsula were formed. Diatom assemblage data allow the estimation of the sea level position at 5700 cal yr BP at least 7 m below present-day mean sea level. Attenuation of the sea-level rise at that time was a major driving mechanism that permitted the establishment of an incipient beach–dune complex, causing water-logging in the Traba basin. However, the location of this incipient wetland on a basement high, which prevented an open connection to the sea, made topographic inheritance the main forcing factor in the subsequent evolution of the wetland. Thus, Traba was never a coastal lagoon system, as it has sometimes been defined. The maximum permeability of the beach–dune complex enclosing the wetland was recorded after its origin until 2900 cal yr BP, when increased stormy conditions affected the Galician shelf waters. Since then, the evolution of the wetland has been mainly controlled by more local factors, especially the continental sediment supply. Changes in land use in the basin have accelerated the infilling of the water body since the 19th century. This rapid infilling makes the whole system more prone to total encroachment in the short term, rather than to sea drowning. Palaeoenvironmental analyses showing the main trends in the long-term evolution of coastal wetlands can be of key importance in any management decisions aimed at preserving these kinds of sensitive coastal environments.Ministerio de Ciencia y Tecnología; REN2000-0468Ministerio de Ciencia y Tecnología; CGL2004-0048BT

    Physical properties of soil in the early stage of an agroforestry system in the High Andean zone

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    In Nariño, Colombia, land use has generated some problems such as erosion, compaction, lack of fertility, among others, so it is necessary to search for alternatives to mitigate these impacts. The objective of this study was to evaluate some physical properties of the soil in an agroforest system with Morella pubescens (Humb. & Bonpl. ex Willd.) Wilbur with Smallanthussonchifolius (Poepp.) H.Rob, in the experimental farm of Botana, in the city of Pasto, Nariño, where the bulk density, real density, total porosity, structural stability properties and distribution of aggregates were analyzed. The datas were obtained in two phases: f1 and f2 before and after agroforestry system implementation, respectively. A randomized complete block design with three treatments and three replications were used. The treatments corresponded to plant densities, T1: S sonchifoliuos, sowed to 1x1m, T2:0.8x0.8m y T3:0.5x0.5m, with three replications. M pusescens was stablished to 4x4m between plants and 9 m between rows and the control (f1). The statistics have differences between f1 (control) and f2 (treatments), to the structural stability properties and distribution of aggregates. The ground suffered a structural stability change to stable lightly (0.97 D.P.M) in f1 to a stable moderate (2.53 D.P.M), in f2. The distribution of aggregates passed to 60% in f1 to 70.3% in f2, with a media aggregation status. The different agroforest systems management could help, in the long term, by improving the structure of the ground through the vegetal material of arboreal component, the application of a minimum farming and the addition of organic matter

    Bicellar systems to modify the phase behaviour of skin stratum corneum lipids

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    Bicellar systems are a fascinating category of versatile lipid assemblies that comprise bilayered disk-shaped nanoaggregates formed in water by long and short alkyl chain phospholipids. Bicelles bridge the gap between micelles and lipid vesicles by combining the attractive properties of both systems. These structures have recently been proposed in dermatological, cosmetic and pharmaceutical applications. Two new binary bicellar systems composed of cholesterol sulphate (SCHOL) and long-chain phospholipids (dimyristoyl- phosphatidylcholine, DMPC, or dipalmitoyl-phosphatidylcholine, DPPC) are characterised herein by differential scanning calorimetry, fluorescence spectroscopy, X-ray scattering and microscopy. Additionally, a comparative study on skin treated with the new SCHOL systems (DMPC/SCHOL and DPPC/SCHOL) and classic DHPC systems (DMPC/DHPC and DPPC/DHPC) was performed. These studies were conducted to determinate how deeply bicelles penetrate into the skin and the extension of their effect on the phase behaviour of stratum corneum (SC) lipids using attenuated total reflectance-Fourier transform infrared spectroscopy and two-photon excitation fluorescence microscopy. Our results show that SCHOL modified the typical discoidal morphology and the phase behaviour of the systems, inducing coexistence of two phases, liquid-ordered and ripple phases. The effect of the systems on SC lipids depends on their composition and is related to the fluidity of the SC lipid alkyl chains. Thus, systems with DMPC induced more disorder in SC lipids than systems with DPPC, and SCHOL did not modify the lipid arrangement. Perdeuterated systems in the infrared spectroscopy technique supported a different distribution in the tissue for every system. DMPC systems were primarily at the first layers of the SC, whereas DPPC systems were more widely distributed. Systems with SCHOL had enhanced distribution and penetration of bicellar systems throughout the SC. This journal is © 2012 the Owner Societies

    R353Q polymorphism in the factor VII gene and cardiovascular risk in Heterozygous Familial Hypercholesterolemia: a case-control study

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    <p>Abstract</p> <p>Background</p> <p>Heterozygous Familial Hypercholesterolemia (FH) is a genetic disorder characterized by a high risk of cardiovascular disease. Certain polymorphisms of the factor VII gene have been associated with the development of coronary artery disease and there is a known association between factor VII levels and polymorphic variants in this gene. To date, no study has evaluated the association between factor VII and coronary artery disease in patients with FH.</p> <p>Results</p> <p>This case-control study comprised 720 patients (546 with FH and 174 controls). We determined the prevalence and allele frequencies of the R353Q polymorphism of factor VII, the plasma levels of factor VII antigen (FVII Ag) and whether they could be predictive factors for cardiovascular risk. 75% (410) of the patients with FH were RR, 23% (127) RQ and 1.6% (9) QQ; in the control group 75.3% (131) were RR, 21.3% (37) RQ and 3.4% (6) QQ (p = 0.32). No statistically significant associations were observed in the distribution of genotypes and allele frequencies between case (FH) and control groups. Nor did we find differences when we evaluated the relationship between the R353Q polymorphism and cardiovascular risk (including coronary disease, ischemic stroke and peripheral arterial disease), either in the univariate analysis or after adjustment for sex, age, arterial hypertension, body mass index, xanthomas, diabetes, smoking, HDLc and LDLc and lipid-lowering treatment. The FVII Ag concentrations behaved in a similar fashion, with no differences for the interaction between controls and those with FH (RR vs. RQ/QQ; p = 0.96). In the subgroup of patients with FH no association was found among cardiovascular disease, genotype and FVII Ag levels (RR vs. RQ/QQ; p = 0.97).</p> <p>Conclusions</p> <p>Our study did not find a direct relationship between cardiovascular risk in patients with Heterozygous Familial Hypercholesterolemia, the R353Q polymorphism of factor VII and FVII Ag levels.</p

    Design and methodological characteristics of studies using observational routinely collected health data for investigating the link between cancer and neurodegenerative diseases: protocol for a meta-research study

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    Introduction: Health services generate large amounts of routine health data (eg, administrative databases, disease registries and electronic health records), which have important secondary uses for research. Increases in the availability and the ability to access and analyse large amounts of data represent a major opportunity for conducting studies on the possible relationships between complex diseases. The objective of this study will be to evaluate the design, methods and reporting of studies conducted using observational routinely collected health data for investigating the link between cancer and neurodegenerative diseases. Methods and analysis: This is the protocol for a meta-research study. We registered the study protocol within the Open Science Framework: https://osf.io/h2qjg. We will evaluate observational studies (eg, cohort and case-control) conducted using routinely collected health data for investigating the associations between cancer and neurodegenerative diseases (such as Alzheimer's disease, amyotrophic lateral sclerosis/motor neuron disease, Huntington's disease, multiple sclerosis and Parkinson's disease). The following electronic databases will be searched (from their inception onwards): MEDLINE, Embase and Web of Science Core Collection. Screening and selection of articles will be conducted by at least two researchers. Potential discrepancies will be resolved via discussion. Design, methods and reporting characteristics in each article will be extracted using a standardised data extraction form. Information on general, methodological and transparency items will be reported. We will summarise our findings with tables and graphs (eg, bar charts, forest plots). Ethics and dissemination: Due to the nature of the proposed study, no ethical approval will be required. We plan to publish the full study in an open access peer-reviewed journal and disseminate the findings at scientific conferences and via social media. All data will be deposited in a cross-disciplinary public repository.FC-L and RT-S are supported by the Institute of Health Carlos III/CIBERSAM. MJP is supported by an Australian Research Council Discovery Early Career Researcher Award (DE200101618). MR and EB-D are partially funded by the Spanish Health Services Research on Chronic Patients Network (REDISSEC)/Institute of Health Carlos III.S

    Minimizing acquisition-related radiomics variability by image resampling and batch effect correction to allow for large-scale data analysis

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    Objective: To identify CT-acquisition parameters accounting for radiomics variability and to develop a post-acquisition CTimage correction method to reduce variability and improve radiomics classification in both phantom and clinical applications. Methods: CT-acquisition protocols were prospectively tested in a phantom. The multi-centric retrospective clinical study included CT scans of patients with colorectal/renal cancer liver metastases. Ninety-three radiomics features of first order and texture were extracted. Intraclass correlation coefficients (ICCs) between CT-acquisition protocols were evaluated to define sources of variability. Voxel size, ComBat, and singular value decomposition (SVD) compensation methods were explored for reducing the radiomics variability. The number of robust features was compared before and after correction using two-proportion z test. The radiomics classification accuracy (K-means purity) was assessed before and after ComBat- and SVD-based correction. Results: Fifty-three acquisition protocols in 13 tissue densities were analyzed. Ninety-seven liver metastases from 43 patients with CT from two vendors were included. Pixel size, reconstruction slice spacing, convolution kernel, and acquisition slice thickness are relevant sources of radiomics variability with a percentage of robust features lower than 80%. Resampling to isometric voxels increased the number of robust features when images were acquiredwith different pixel sizes (p < 0.05). SVD-based for thickness correction and ComBat correction for thickness and combined thickness–kernel increased the number of reproducible features (p < 0.05). ComBat showed the highest improvement of radiomics-based classification in both the phantom and clinical applications (K-means purity 65.98 vs 73.20). Conclusion: CT-image post-acquisition processing and radiomics normalization by means of batch effect correction allow for standardization of large-scale data analysis and improve the classification accuracy

    Application of Machine Learning to Electroencephalography for the Diagnosis of Primary Progressive Aphasia: A Pilot Study

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    Primary progressive aphasia (PPA) is a neurodegenerative syndrome in which diagnosis is usually challenging. Biomarkers are needed for diagnosis and monitoring. In this study, we aimed to evaluate Electroencephalography (EEG) as a biomarker for the diagnosis of PPA. Methods. We conducted a cross-sectional study with 40 PPA patients categorized as non-fluent, semantic, and logopenic variants, and 20 controls. Resting-state EEG with 32 channels was acquired and preprocessed using several procedures (quantitative EEG, wavelet transformation, autoencoders, and graph theory analysis). Seven machine learning algorithms were evaluated (Decision Tree, Elastic Net, Support Vector Machines, Random Forest, K-Nearest Neighbors, Gaussian Naive Bayes, and Multinomial Naive Bayes). Results. Diagnostic capacity to distinguish between PPA and controls was high (accuracy 75%, F1-score 83% for kNN algorithm). The most important features in the classification were derived from network analysis based on graph theory. Conversely, discrimination between PPA variants was lower (Accuracy 58% and F1-score 60% for kNN). Conclusions. The application of ML to resting-state EEG may have a role in the diagnosis of PPA, especially in the differentiation from controls. Future studies with high-density EEG should explore the capacity to distinguish between PPA variants

    Impact of HLA Mismatching on Early Subclinical Inflammation in Low-Immunological-Risk Kidney Transplant Recipients

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    The impact of human leukocyte antigen (HLA)-mismatching on the early appearance of subclinical inflammation (SCI) in low-immunological-risk kidney transplant (KT) recipients is undetermined. We aimed to assess whether HLA-mismatching (A-B-C-DR-DQ) is a risk factor for early SCI. As part of a clinical trial (Clinicaltrials.gov, number NCT02284464), a total of 105 low-immunological-risk KT patients underwent a protocol biopsy on the third month post-KT. As a result, 54 presented SCI, showing a greater number of total HLA-mismatches (p = 0.008) and worse allograft function compared with the no inflammation group (48.5 ± 13.6 vs. 60 ± 23.4 mL/min; p = 0.003). Multiple logistic regression showed that the only risk factor associated with SCI was the total HLA-mismatch score (OR 1.32, 95%CI 1.06-1.64, p = 0.013) or class II HLA mismatching (OR 1.51; 95%CI 1.04-2.19, p = 0.032) after adjusting for confounder variables (recipient age, delayed graft function, transfusion prior KT, and tacrolimus levels). The ROC curve illustrated that the HLA mismatching of six antigens was the optimal value in terms of sensitivity and specificity for predicting the SCI. Finally, a significantly higher proportion of SCI was seen in patients with >6 vs. ≤6 HLA-mismatches (62.3 vs. 37.7%; p = 0.008). HLA compatibility is an independent risk factor associated with early SCI. Thus, transplant physicians should perhaps be more aware of HLA mismatching to reduce these early harmful lesions

    Colon cancer therapy with calcium phosphate nanoparticles loading bioactive compounds from Euphorbia lathyris: In vitro and in vivo assay

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    Amorphous calcium phosphate nanoparticles (ACP NPs) exhibit excellent biocompatibility and biodegradability properties. ACP NPs were functionalized with two coumarin compounds (esculetin and euphorbetin) extracted from Euphorbia lathyris seeds (BC-ACP NPs) showing high loading capacity (0.03% and 0.34% (w/w) for esculetin and euphorbetin, respectively) and adsorption efficiency (2.6% and 33.5%, respectively). BC-ACP NPs, no toxic to human blood cells, showed a more selective cytotoxicity against colorectal cancer (CRC) cells (T-84 cells) (IC50, 71.42 μg/ml) compared to non-tumor (CCD18) cells (IC50, 420.77 μg/ml). Both, the inhibition of carbonic anhydrase and autophagic cell death appeared to be involved in their action mechanism. Interestingly, in vivo treatment with BC-ACPs NPs using two different models of CRC induction showed a significant reduction in tumor volume (62%) and a significant decrease in the number and size of polyps. A poor development of tumor vasculature and invasion of normal tissue were also observed. Moreover, treatment increased the bacterial population of Akkermansia by restoring antioxidant systems in the colonic mucosa of mice. These results show a promising pathway to design innovative and more efficient therapies against CRC based on biomimetic calcium phosphate NPs loaded with natural products.Spanish GovernmentEuropean Commission PTQ-17-09172 RTC-2017-6540-1 RTI2018-100934-B-I00 RTC2019-006870-1 RYC2016-21042Junta de Andalucia FEDER program P18-TP-1420 A-CTS666-UGR20 B-CTS-122-UGR20 P18-HO-3882 P18-TP-0969Andalusian Government AGR145 FQM-368 CTS-10

    Clinical Relevance of Corticosteroid Withdrawal on Graft Histological Lesions in Low-Immunological-Risk Kidney Transplant Patients

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    The impact of corticosteroid withdrawal on medium-term graft histological changes in kidney transplant (KT) recipients under standard immunosuppression is uncertain. As part of an open-label, multicenter, prospective, phase IV, 24-month clinical trial (ClinicalTrials.gov, NCT02284464) in low-immunological-risk KT recipients, 105 patients were randomized, after a protocol-biopsy at 3 months, to corticosteroid continuation (CSC, n = 52) or corticosteroid withdrawal (CSW, n = 53). Both groups received tacrolimus and MMF and had another protocol-biopsy at 24 months. The acute rejection rate, including subclinical inflammation (SCI), was comparable between groups (21.2 vs. 24.5%). No patients developed dnDSA. Inflammatory and chronicity scores increased from 3 to 24 months in patients with, at baseline, no inflammation (NI) or SCI, regardless of treatment. CSW patients with SCI at 3 months had a significantly increased chronicity score at 24 months. HbA1c levels were lower in CSW patients (6.4 +/- 1.2 vs. 5.7 +/- 0.6%; p = 0.013) at 24 months, as was systolic blood pressure (134.2 +/- 14.9 vs. 125.7 +/- 15.3 mmHg; p = 0.016). Allograft function was comparable between groups and no patients died or lost their graft. An increase in chronicity scores at 2-years post-transplantation was observed in low-immunological-risk KT recipients with initial NI or SCI, but CSW may accelerate chronicity changes, especially in patients with early SCI. This strategy did, however, improve the cardiovascular profiles of patients
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