1,784 research outputs found

    Computational and analytical studies of the harmonic index on Erdös-Rényi models

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    A main topic in the study of topological indices is to find bounds of the indices involving several parameters and/or other indices. In this paper we perform statistical (numerical) and analytical studies of the harmonic index H(G), and other topological indices of interest, on Erdos-Rényi (ER) graphs G(n, p) characterized by n vertices connected independently with probability p ∈ (0, 1). Particularly, in addition to H(G), we study here the (−2) sum-connectivity index χ−2(G), the modified Zagreb index MZ(G), the inverse degree index ID(G) and the Randic index R(G). First, to perform the statistical study of these indices, we define the averages of the normalized indices to their maximum value: {H(G)}, {χ−2(G)}, {MZ(G)}, {ID(G)}, {R(G)}. Then, from a detailed scaling analysis, we show that the averages of the normalized indices scale with the product ξ ≈ np. Moreover, we find two different behaviors. On the one hand, hH(G)i and hR(G)i, as a function of the probability p, show a smooth transition from zero to n/2 as p increases from zero to one. Indeed, after scaling, it is possible to define three regimes: a regime of mostly isolated vertices when ξ 10 (H(G), R(G) ≈ n/2). On the other hand, hχ−2(G)i, hMZ(G)i and hID(G)i increase with p until approaching their maximum value, then they decrease by further increasing p. Thus, after scaling the curves corresponding to these indices display bell-like shapes in log scale, which are symmetric around ξ ≈ 1; i.e. the percolation transition point of ER graphs. Therefore, motivated by the scaling analysis, we analytically (i) obtain new relations connecting the topological indices H, χ−2, MZ, ID and R that characterize graphs which are extremal with respect to the obtained relations and (ii) apply these results in order to obtain inequalities on H, χ−2, MZ, ID and R for graphs in ER models.J.A.M.-B. acknowledges financial support from FAPESP (Grant No. 2019/ 06931-2), Brazil, CONACyT (Grant No. 2019-000009-01EXTV-00067) and PRODEP-SEP (Grant No. 511-6/2019.-11821), Mexico. J.M.R. and J.M.S. acknowledge financial support from Agencia Estatal de Investigación (PID2019-106433GB-I00/AEI/ 10.13039/501100011033), Spain

    Impact of global and subjective mini nutritional assessment (MNA) questions on the evaluation of the nutritional status: The role of gender and age

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    Undernutrition is a quite common condition in the elderly, often identified using the mini nutritional assessment (MNA) test. The aim of this research was to study the independent value of the global and the subjective MNA questions to predict the undernutrition according to the full MNA score, and to analyze the influence of gender and age on such items. A total of 22,007 Spanish people 65 years of age or older were evaluated using the MNA test. These data were obtained by trained community pharmacists by using receiver Operating Characteristic (ROC) curves. About 4.3% of the studied population were classified as undernourished according to the full MNA test. The subjective subscore (two questions) presented better predictive value than the global one (six questions). Indeed, 99.5% of subjects detected as well nourished using the MNA test were also correctly classified using the two subjective questions. In the present study, it was identified that the two subjective MNA questions can be an efficient tool for a quick screening to rule out non undernourished subjects

    Valoración de la circunferencia de la pantorrilla como indicador de riesgo de desnutrición en personas mayores

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    BACKGROUND: Undernutrition is a very common situation among elderly, that is associated with increased morbidity and mortality rates. On the other hand, calf circumference (CC) is a direct anthropometric measurement, related to fat free mass. An early detection of an elderly undernutrition situation, based on CC assessment, could contribute to prevent its development and consequences. OBJECTIVE: To analyse the relationship between CC and a possible undernutrition situation, based on the application of the Mini Nutritional Assessment (MNA) test, among Spanish subjects of 65 or more years old, including the gender and age influences. SUBJECTS AND METHODS: A cross-sectional study was carried out to assess the nutritional situation of an ambulatory population, from every area of Spanish geography (n = 22007), using the questionnaire MNA. Every subject surveyed was 65 or more years old when the test was done. RESULTS: There were statistically significant differences between subjects with a CC or= 31 cm, both men and women, in weight, height, body mass index (BMI), MNA total score and undernutrition classification. On the other hand, it was found that those elders with lower CC showed a higher undernutrition risk, both men and women, in every age range studied. CONCLUSIONS: It does exit an association between CC of Spanish subjects of 65 or more years old and the risk of developing undernutrition. That association is similar among men and women, and in all age ranges

    Food consumption analysis in Spanish elderly based upon the Mini Nutritional Assessment Test

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    Background/Aims: Aged people are an increasing population group worldwide, and nutritional impairments may contribute to additional health problems. The characterization of food consumption of elderly people is a good approach to implementing adequate nutritional policies in order to improve their nutritional status. The aim of this study was to describe and analyze specific aspects of food intake based upon the Mini Nutritional Assessment (MNA) test in a representative country sample. Methods: The survey consisted of a cross-sectional study assessing the nutritional status of 22,007 Spanish people aged 65 years or older using the MNA test. These data, including dietary information, were obtained by health professionals specifically trained to carry out the questionnaire. A multiple regression analysis was used to evaluate the contributing impact of the diet-related MNA questions on the total MNA score. Results: Differences in the food choices between men and women were found, but not in the mode of feeding. Obese and non-obese individuals, categorized by a body mass index (BMI) more or less than 30, showed similar intake patterns of protein-rich foods, but differences in fruits, vegetables and fluids. On the other hand, undernourished and non-undernourished subjects, according to the MNA criteria, revealed different food consumption. Loss of appetite and mode of feeding were the items with the highest influence the MNA total score. Conclusions: While age, gender and BMI considered together are responsible for 11.3% of the total MNA score, dietary-related items can predict the 62.4% of the total MNA classification in the overall elderly Spanish population

    Effect of resistance training and hypocaloric diets with different protein content on body composition and lipid profile in hypercholesterolemic obese women

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    Lifestyle changes such as following a hypocaloric diet and regular physical exercise are recognized as effective non-pharmacological interventions to reduce body fat mass and prevent cardiovascular disease risk factors. Purpose: To evaluate the interactions of a higher protein (HP) vs. a lower protein (LP) diet with or without a concomitant progressive resistance training program (RT) on body composition and lipoprotein profile in hypercholesterolemic obese women. Methods: Retrospective study derived from a 16-week randomized controlled-intervention clinical trial. Twentyfive sedentary, obese (BMI: 30-40 kg/m²) women, aged 40-60 with hypercholesterolemia were assigned to a 4-arm trial using a 2 x 2 factorial design (Diet x Exercise). Prescribed diets had the same calorie restriction (-500 kcal/day), and were categorized according to protein content as: lower protein ( 22% daily energy intake, HP). Exercise comparisons involved habitual activity (control) vs. a 16-week supervised whole-body resistance training program (RT), two sessions/wk. Results: A significant decrease in weight and waist circumference was observed in all groups. A significant decrease in LDL-C and Total-Cholesterol levels was observed only when a LP diet was combined with a RT program, the RT being the most determining factor. Interestingly, an interaction between diet and exercise was found concerning LDL-C values. Conclusion: In this study, resistance training plays a key role in improving LDL-C and Total-Cholesterol; however, a lower protein intake (< 22% of daily energy intake as proteins) was found to achieve a significantly greater reduction in LDL-C

    Versatile Graphene-Based Platform for Robust Nanobiohybrid Interfaces

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    Technologically useful and robust graphene-based interfaces for devices require the introduction of highly selective, stable, and covalently bonded functionalities on the graphene surface, whilst essentially retaining the electronic properties of the pristine layer. This work demonstrates that highly controlled, ultrahigh vacuum covalent chemical functionalization of graphene sheets with a thiol-terminated molecule provides a robust and tunable platform for the development of hybrid nanostructures in different environments. We employ this facile strategy to covalently couple two representative systems of broad interest: metal nanoparticles, via S-metal bonds, and thiol-modified DNA aptamers, via disulfide bridges. Both systems, which have been characterized by a multi-technique approach, remain firmly anchored to the graphene surface even after several washing cycles. Atomic force microscopy images demonstrate that the conjugated aptamer retains the functionality required to recognize a target protein. This methodology opens a new route to the integration of high-quality graphene layers into diverse technological platforms, including plasmonics, optoelectronics, or biosensing. With respect to the latter, the viability of a thiol-functionalized chemical vapor deposition graphene-based solution-gated field-effect transistor array was assessed

    Neuroprotective and anti-inflammatory effects of linoleic acid in models of parkinson’s disease: the implication of lipid droplets and lipophagy

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    Parkinson’s disease (PD) is the second most prevalent neurodegenerative disease after Alzheimer’s disease. The principal pathological feature of PD is the progressive loss of dopaminergic neurons in the ventral midbrain. This pathology involves several cellular alterations: oxidative stress, mitochondrial dysfunction, loss of proteostasis, and autophagy impairment. Moreover, in recent years, lipid metabolism alterations have become relevant in PD pathogeny. The modification of lipid metabolism has become a possible way to treat the disease. Because of this, we analyzed the effect and possible mechanism of action of linoleic acid (LA) on an SH-SY5Y PD cell line model and a PD mouse model, both induced by 6-hydroxydopamine (6-OHDA) treatment. The results show that LA acts as a potent neuroprotective and anti-inflammatory agent in these PD models. We also observed that LA stimulates the biogenesis of lipid droplets and improves the autophagy/lipophagy flux, which resulted in an antioxidant effect in the in vitro PD model. In summary, we confirmed the neuroprotective effect of LA in vitro and in vivo against PD. We also obtained some clues about the novel neuroprotective mechanism of LA against PD through the regulation of lipid droplet dynamics.This research was supported by the Health Institute “Carlos III”-CIBERNED (CB06/05/0041 and 2015/03), “MINECO” (SAF2014-52940-R, SAF2017-85199-P and SAF 2016-78666-R), “Comunidadde Madrid” (PEJ-2019-AI/SAL-12877), “Erasmus+ funding programme”, UCM-Santander (PR44/21-29931 to J.A.M.-G.), and partially supported by “Fondo Europeo de Desarrollo Regional” (FEDER) from the European Union

    Circulating Tumor Cells Enumeration from the Portal Vein for Risk Stratification in Early Pancreatic Cancer Patients

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    [Simple Summary] Effective biomarkers are needed to enable personalized medicine for pancreatic cancer patients. This study analyzes the prognostic value, in early pancreatic cancer, of circulating tumor cells and clusters from the central venous catheter and portal blood. Circulating tumor cells were isolated using an immunomagnetic selection and were detected by microscopy using immunocytochemistry staining. In conclusion, the circulating tumor cell number in portal blood identifies a death risk in patients with early pancreatic cancer.[Abstract] Background. Effective biomarkers are needed to enable personalized medicine for pancreatic cancer patients. This study analyzes the prognostic value, in early pancreatic cancer, of single circulating tumor cell (CTC) and CTC clusters from the central venous catheter (CVC) and portal blood (PV). Methods. In total, 7 mL of PV and CVC blood from 35 patients with early pancreatic cancer were analyzed. CTC were isolated using a positive immunomagnetic selection. The detection and identification of CTC were performed by immunocytochemistry (ICC) and were analyzed by Epi-fluorescence and confocal microscopy. Results. CTC and the clusters were detected both in PV and CVC. In both samples, the CTC number per cluster was higher in patients with grade three or poorly differentiated tumors (G3) than in patients with well (G1) or moderately (G2) differentiated. Patients with fewer than 185 CTC in PV exhibited a longer OS than patients with more than 185 CTC (24.5 vs. 10.0 months; p = 0.018). Similarly, patients with fewer than 15 clusters in PV showed a longer OS than patients with more than 15 clusters (19 vs. 10 months; p = 0.004). These significant correlations were not observed in CVC analyses. Conclusions. CTC presence in PV could be an important prognostic factor to predict poor prognosis in early pancreatic cancer. In addition, the number of clustered-CTC correlate to a tumor negative differentiation degree and, therefore, could be used as a diagnostic biomarker for pancreatic cancer.This research was funded by Carlos III Health Institute (Health Research Fund) grant number PI16/01465 and PI19/01821 (Co-financed by the European Regional Development Fund “A way to make Europe”)

    Involvement of stanniocalcins in the deregulation of glycaemia in obese mice and type 2 diabetic patients

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    Las estanniocalcinas se expresan en el tejido del páncreas, y se sugirió una correlación directa entre la insulina circulante y las concentraciones de STC2 en el ser humano. Aquí, mostramos una correlación significativa entre STC1 y tanto la glucemia como la hemoglobina glicosilada entre los pacientes con DM2, mientras que los pacientes con DM2 que presentan los mayores valores de hemoglobina glicosilada exhibieron la menor expresión de STC2. Sin embargo, el tratamiento de los pacientes con fármacos antiglicémicos no modifica significativamente la expresión de ambas STC. Por otra parte, los ratones STC2-/- que mostraron sobrepeso neonatal y adulto presentaron además una glucemia desregulada cuando fueron alimentados con una dieta hipercalórica (pellet de cría, BP). Esta alteración es más evidente en las primeras etapas de la vida animal. La glucemia desregulada en estos ratones se confirmó mediante una prueba oral de glucosa. Además, los ratones STC2-/- presentan un aumento del tamaño del páncreas; así, el análisis histológico revela que los ratones WT responden a la dieta BP aumentando el tamaño de los islotes pancreáticos a través de la inducción de la división celular, y los ratones STC2-/- carecen de este mecanismo compensatorio. Contrariamente, los ratones alimentados con STC2-/- muestran un mayor número de islotes pero de tamaño similar a los alimentados con el pellet regular. El análisis histopatológico demuestra la alteración de la estructura de los tejidos y las infiltraciones de eritrocitos en los ratones STC2-/-, posiblemente debido al estrés evocado por la dieta BP. Por último, se observó una mayor inmunotinción de glucagón en el islote de los ratones STC2-/-, y el ensayo ELISA de glucagón confirmó el aumento del glucagón circulante. En resumen, presentamos pruebas del papel de los STC, principalmente el STC2, como posible marcador temprano durante el desarrollo de la diabetes mellitus.Stanniocalcins are expressed in the pancreas tissue, and it was suggested a direct correlation between circulating insulin and STC2 concentrations in human. Here, we show a significant correlation between STC1 and both glycaemia and glycosylated haemoglobin among DM2 patients, while DM2 patients who present the greatest glycosylated haemoglobin values exhibited the lowest STC2 expression. However, treatment of patients with antiglycaemic drugs does not significantly modify the expression of both STCs. On the other hand, STC2-/- mice that exhibited neonatal and adult overweight further presented deregulated glycaemia when they were feed with a hypercaloric diet (breeding pellet, BP). This alteration is more evident at the early stages of the animal life. Deregulated glycaemia in these mice was confirmed using glucose oral test. In addition, STC2-/- mice present enhanced pancreas size; thus, the histological analysis reveals that WT mice respond to BP diet by increasing the size of the pancreatic islets through inducing cell division, and STC2-/- mice lack this compensatory mechanism. Contrary, BP fed STC2-/- mice show enhanced number of islets but of similar size than those fed with regular pellet. Histopathological analysis demonstrates tissue structure disruption and erythrocytes infiltrations in STC2-/- mice, possibly due to the stress evoked by the BP diet. Finally, enhanced glucagon immunostaining was observed in the islet of STC2-/- mice, and the glucagon ELISA assay confirmed the increase in the circulating glucagon. Summarizing, we present evidence of the role of STCs, mainly STC2, as a possible early marker during development of diabetes mellitus.• Ministerio de Economía y Competitividad. Becas 2013‐45564C2‐1‐P, BFU‐2016‐74932‐C2‐1‐P • Programa Juan de la Cierva. Becas IJCI‐2015‐25665, JC‐2012‐ 2934 • Junta de Extremadura. Beca PRIIB16046peerReviewe

    Dietary total antioxidant capacity and obesity in children and adolescents

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    Dietary antioxidant intake has been suggested to protect against oxidative damage and related clinical complications. The aim of this study was to assess the potential relationships between the dietary total antioxidant capacity (TAC) and obesity-related features in children and adolescents. Anthropometric variables from 369 children and adolescents were measured (184 obese and 185 control). A validated food-frequency questionnaire was used to calculate the TAC and the daily nutrient and energy intake. Dietary TAC showed positive associations with fiber, folic acid, magnesium, and vitamins A, C and E. BMI, SDS-BMI and total body fat were inversely associated with dietary TAC only in obese subjects. These data suggest that dietary TAC may be a potential indicator of the risk to develop obesity-related features and could be considered as a useful method in assessing antioxidant intake
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