2,039 research outputs found

    The Correlated Block Renormalization Group

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    We formulate the standard real-space renormalization group method in a way which takes into account the correlation between blocks. This is achieved in a dynamical way by means of operators which reflect the influence on a given block of its neighbours. We illustrate our method in the example of the tight-binding model in 1D and 2D for various types of boundary conditions.Comment: LATEX file, 18 pages, 7 figures available upon reques

    Low-fat dairy consumption and reduced risk of hypertension: the Seguimiento Universidad de Navarra (SUN) cohort

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    BACKGROUND: Some observational studies have shown a beneficial effect of dairy consumption on blood pressure, especially in overweight and relatively young (<40 y) persons. However, no results from prospective studies conducted in a free-living population exist that show this association in middle-aged adults. OBJECTIVE: The aim of the present study was to assess whether total, low-fat, and whole-fat dairy consumption was associated prospectively with the risk of hypertension. DESIGN: This was a prospective study conducted in 5880 university graduates in Spain, aged >20 y in 2000 (mean age: 37 y), free of hypertension and cardiovascular disease at baseline, and followed-up with mailed questionnaires for a median of 27 mo. Dairy consumption was assessed with a previously validated semiquantitative food-frequency questionnaire. RESULTS: One hundred eighty new cases of hypertension were identified. The hazard ratio of hypertension between extreme quintiles of low-fat dairy product consumption was 0.46 (95% CI: 0.26, 0.84; P for trend = 0.02) after adjustment for the main known risk factors for hypertension and several dietary factors. No significant association between whole-fat dairy products or total calcium intake and incident hypertension was seen. CONCLUSION: In this Mediterranean cohort, low-fat dairy consumption, but not whole-fat dairy consumption, was associated with a lower risk of incident hypertension

    New Perspectives for Electrodialytic Remediation

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    Electrodialytic remediation has been widely used for the recovery of different contaminants from numerous matrices, such as, for example, polluted soils, wastewater sludge, fly ash, mine tailing or harbour sediments. The electrodialytic remediation is an enhancement of the electrokinetic remediation technique, and it consists of the use of ion-exchange membranes for the control of the acid and the alkaline fronts generated in the electrochemical processes. While the standard electrodialytic cell is usually built with three-compartment configuration, it has been shown that for the remediation of matrices that require acid environment, a two-compartment cell has given satisfactory removal efficiencies with reduced energy costs. Recycling secondary batteries, with growing demand, has an increasing economic and environmental interest. This work focusses on the proposal of the electrodialytic remediation technique as a possible application for the recycling of lithium-ion cells and other secondary batteries. The recovery of valuable components, such as lithium, manganese, cobalt of phosphorous, based on current recycling processes and the characterization of solid waste is addressed.This work has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No. 778045. Paz-Garcia acknowledges the financial support from the University of Malaga, project: PPIT.UMA.B5.2018/17. Villen-Guzman acknowledges the funding from the University of Malaga for the postdoctoral fellowship PPIT.UMA.A.3.2.2018. Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

    Electrodialytic Recovery of Cobalt from Spent Lithium-Ion Batteries

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    Contribución en congreso científicoRecycling lithium-ion batteries has an increasing interest for economic and environmental reasons. Disposal of lithium-ion batteries imposes high risk to the environment due to the toxicity of some of their essential components. In addition to this, some of these components, such as cobalt, natural graphite and phosphorus, are included in the list of critical raw materials for the European Union due to their strategic importance in the manufacturing industry. Therefore, in the recent years, numerous research studies have been focused on the development of efficient processes for battery recycling and the selective recuperation of these key components. LiCoO2 is the most common material use in current lithium-ion batteries cathodes. In the current work, an electrodialytic method is proposed for the recovery of cobalt from this kind of electrode. In a standard electrodialytic cell, the treated matrix is separated from the anode and the cathode compartments by means of ion-exchange membranes. A cation-exchange membrane (CEM) allows the passage of cations and hinders the passage of anions, while the behaviour of anion-exchange membrane (AEM) does the opposite. A three-compartment electrodialytic cell has been designed and assembled, as depicted in the figure. In the central compartment, a suspension of LiCoO2 is added. Different extracting agents, such as EDTA, HCl and HNO3, are tested to enhanced the dissolution and the selective extraction of the target metal. Dissolved cobalt-containing complexes migrate towards the cathode or the anode compartments depending on the ionic charge of the complexes. While cobalt extraction via extracting agents is an expensive treatment, as it requires the constant addition of chemicals, an efficient electrodialytic cell could allow the recirculation of the extracting agents and the economical optimization of the process.This work has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No. 778045. Paz-Garcia acknowledges the financial support from the University of Malaga, project: PPIT.UMA.B5.2018/17. Villen-Guzman acknowledges the funding from the University of Malaga for the postdoctoral fellowship PPIT.UMA.A.3.2.2018. Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

    First sexual intercourse and subsequent regret in three developing countries

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    Purpose: Adolescents who engage in sex can be affected by a range of negative physical and psychological consequences. We intend to analyze the reasons behind first sex, regret, and the association between reasons and regret. Methods: A questionnaire was implemented to 8495 high schools students, aged 14-18, in the Philippines, El Salvador and Peru. Sexually active participants responded whether several circumstances were reasons involved in their first sexual relationship. They also responded whether they regretted having already had sexual relationships. Results: More than a third of respondents reported at least one external pressure leading to first sex, and about half reported at least one reason implying getting carried away by sexual arousal. More females affirmed they regret having already had sex. Logistic regression shows that reasons for first sex associated with regret were partner insistence, "uncontrolled situations" and seeing sexual images. These reasons were associated with regret even when love was also reported as related to first sex. Conclusions: Adolescent sexual experience is often motivated by pressure and circumstances that lower the control over their decisions concerning sex, such as external pressure (because most friends already had sex or because of partner insistence) or getting carried away by sexual arousal (through an "uncontrolled situation" or viewing sexual images) rather than by mature decisions, and this may result in later regret. Adolescents should be helped by parents, educators and policy makers to be aware of these characteristics of adolescent sex and empowered to make assertive and informed decisions concerning their sexuality

    Naturally lignan-rich foods: a dietary tool for health promotion?

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    Dietary guidelines universally advise adherence to plant-based diets. Plant-based foods confer considerable health benefits, partly attributable to their abundant micronutrient (e.g., polyphenol) content. Interest in polyphenols is largely focused on the contribution of their antioxidant activity to the prevention of various disorders, including cardiovascular disease and cancer. Polyphenols are classified into groups, such as stilbenes, flavonoids, phenolic acids, lignans and others. Lignans, which possess a steroid-like chemical structure and are defined as phytoestrogens, are of particular interest to researchers. Traditionally, health benefits attributed to lignans have included a lowered risk of heart disease, menopausal symptoms, osteoporosis and breast cancer. However, the intake of naturally lignan-rich foods varies with the type of diet. Consequently, based on the latest humans’ findings and gathered information on lignan-rich foods collected from Phenol Explorer database this review focuses on the potential health benefits attributable to the consumption of different diets containing naturally lignan-rich foods. Current evidence highlight the bioactive properties of lignans as human health-promoting molecules. Thus, dietary intake of lignan-rich foods could be a useful way to bolster the prevention of chronic illness, such as certain types of cancers and cardiovascular disease

    Lipid Transfer Protein Sensitization: Risk of Anaphylaxis and Molecular Sensitization Profile in Pru p 3-Sensitized Patients

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    Background: Component-resolved diagnosis reveals the IgE response to many inhaled, food, and other allergens, improving the understanding and diagnosis of allergic diseases. Objective: The aims of the study are to study the recognition of different lipid transfer proteins (LTPs) and other allergen families in a large group of people sensitized to Pru p 3 and to analyze the relationship between the clinical entities and the allergens. Methods: This cross-sectional study included a large cohort of patients with positive skin tests to peach fruit and Pru p 3 specific IgE antibodies. Respiratory and food allergy symptoms were collected, and we performed prick tests with pollen, plant food, and other allergens plus the ImmunoCAP ISAC assay. Results: Our sample consisted of 421 people with a mean age of 33.25 years (range 16–68); 54.6% were women. Clinical entities included anaphylaxis (37.1%), urticaria (67.9%), and oral allergy syndrome (59.1%). Rhinitis, rhinoconjunctivitis, and/or asthma were diagnosed in 71.8% of the participants. The most pronounced correlation existed between sensitization to Pru p 3 and to Jug r 3, Pla a 3, Ara h 9, and Cor a 8. We found a higher incidence of anaphylaxis in people with 5 or more recognized LTPs. No association was observed between inhaled and food allergies. Conclusion: Most Pru p 3-sensitized participants were sensitized to additional allergens from the same family and, to a lesser extent, to other allergens, mainly in the profilin and PR-10 protein families. Anaphylaxis occurred in more than a third of the cases evaluated, and almost three-quarters of them had respiratory symptoms. Respiratory and food allergies involving LTPs do not seem to be associated

    Direct toxicity of six antibiotics on soil bacterial communities affected by the addition of bio-adsorbents

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    Reducing the toxicity caused by antibiotics on bacterial communities in the soil is one of the great challenges of this century. For this, the effectiveness of amending the soil with different bioadsorbents such as crushed mussel shell (CMS), pine bark (PB) and biomass ash (BA), as well as combinations of them (CMS + PB and PB + BA) was studied at different doses (0 g kg−1 to 48 g kg−1). Soil samples were spiked, separately, with increasing doses (0–2000 mg kg−1) of cefuroxime (CMX), amoxicillin (AMX), clarithromycin (CLA), azithromycin (AZI), ciprofloxacin (CIP) and trimethoprim (TMP). Their toxicity on bacterial growth was estimated using the tritium-labeled leucine (3H) incorporation method. Toxicity was observed to behave differently depending on the antibiotic family and bioadsorbent, although in different magnitude and at different doses. The toxicity of β-lactams (AMX and CXM) was reduced by up to 54% when the highest doses of bio-adsorbents were added due to the increase in pH (CMS and BA) and carbon (PB) contribution. Macrolides (CLA and AZI) showed slight toxicity in un-amended soil samples, which increased by up to 65% with the addition of the bio-adsorbents. The toxicity of CIP (a fluoroquinolone) increased with the dose of the bio-adsorbents, reaching up to 20% compared with the control. Finally, the toxicity of TMP (a diaminopyrimidine) slightly increased with the dose of bio-adsorbents. The by-products that increase soil pH are those that showed the highest increases of CLA, AZI, CIP and TMP toxicities. These results could help to prevent/reduce environmental pollution caused by different kinds of antibiotics, selecting the most appropriated bio-adsorbents and doses.Agencia Estatal de Investigación | Ref. RTI2018-099574-B-C21Agencia Estatal de Investigación | Ref. RTI2018-099574-B-C22Ministerio de Economía, Industria y Competitividad | Ref. RYC-2016-20411Xunta de Galicia | Ref. ED481B-2022-081Xunta de Galicia | Ref. ED481A-2021/309Financiado para publicación en acceso aberto: Universidade de Vigo/CISU

    Validation of self reported diagnosis of hypertension in a cohort of university graduates in Spain

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    Background: The search for risk factors of hypertension requires the study of large populations. Sometimes, the only feasible way of studying these populations is to rely on self-reported data of the outcome. The objective of this study was to evaluate validity of self-reported diagnosis of hypertension in a cohort of university graduates in Spain. Methods: The Seguimiento Universidad de Navarra (SUN) Study is a cohort of more than 15,000 university graduates in Spain. We selected a random sample of 79 cohort participants who reported a diagnosis of hypertension and 48 participants who did not report such diagnosis (76% participation proportion). Then, we compared information on the self-reported diagnosis of hypertension and hypertension status as assessed through two personal blood pressure measurements and an interview. Additionally, we compared self-reported and measured blood pressure levels with intraclass correlation coefficients and the survival-agreement plot. Results: From those 79 reporting a diagnosis of hypertension, 65 (82.3%, 95% CI 2.8–92.8) were confirmed through conventional measurement of blood pressure and the interview. From those 48 that did not report a diagnosis of hypertension, 41 (85.4%, 95% CI 72.4–89.1) were confirmed as non hypertensives. Results were similar among men and women, but were worse for overweight and obese individuals, and for those with a family history of hypertension. The greement between self-reported and measured blood pressure levels (as a continuous variable), as estimated by the intraclass correlation coefficient, was 0.35 for both systolic and diastolic blood pressure. Conclusion: Self-reported hypertension among highly educated participants in a cohort study is a relatively valid tool to assess the hypertensive status of participants. However, the investigators should be cautious when using self-reported blood pressure values
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