7,051 research outputs found

    Human osteoblasts within soft peptide hydrogels promote mineralisation in vitro

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    Biomaterials that provide three-dimensional support networks for the culture of cells are being developed for a wide range of tissue engineering applications including the regeneration of bone. This study explores the potential of the versatile ionic-complementary peptide, FEFEFKFK, for such a purpose as this peptide spontaneously self-assembles into β-sheet-rich fibres that subsequently self-associate to form self-supporting hydrogels. Via simple live/dead cell assays, we demonstrated that 3 wt% hydrogels were optimal for the support of osteoblast cells. We went on to show that these cells are not only viable within the three-dimensional hydrogel but they also proliferate and produce osteogenic key proteins, that is, they behave like in vivo bone cells, over the 14-day period explored here. The gel elasticity increased over time when cells were present – in comparison to a decrease in control samples – indicating the deposition of matrix throughout the peptide scaffold. Moreover, significant quantities of calcium phosphate were deposited. Collectively, these data demonstrate that ionic-complementary octapeptides offer a suitable three-dimensional environment for osteoblastic cell function

    Osteogenic differentiation of human mesenchymal stem cells promotes mineralization within a biodegradable peptide hydrogel

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    An attractive strategy for the regeneration of tissues has been the use of extracellular matrix analogous biomaterials. Peptide-based fibrillar hydrogels have been shown to mimic the structure of extracellular matrix offering cells a niche to undertake their physiological functions. In this study, the capability of an ionic-complementary peptide FEFEFKFK (F, E, and K are phenylalanine, glutamic acid, and lysine, respectively) hydrogel to host human mesenchymal stem cells in three dimensions and induce their osteogenic differentiation is demonstrated. Assays showed sustained cell viability and proliferation throughout the hydrogel over 12 days of culture and these human mesenchymal stem cells differentiated into osteoblasts simply upon addition of osteogenic stimulation. Differentiated osteoblasts synthesized key bone proteins, including collagen-1 (Col-1), osteocalcin, and alkaline phosphatase. Moreover, mineralization occurred within the hydrogel. The peptide hydrogel is a naturally biodegradable material as shown by oscillatory rheology and reversed-phase high-performance liquid chromatography, where both viscoelastic properties and the degradation of the hydrogel were monitored over time, respectively. These findings demonstrate that a biodegradable octapeptide hydrogel can host and induce the differentiation of stem cells and has the potential for the regeneration of hard tissues such as alveolar bon

    Out-of-pocket health expenditures in Colombia: a systematic review

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    Objectives To review the evidence of out-of-pocket (OOPE) and catastrophic expenditures (CHE) in health in Colombia. Methods Systematic review of the literature (SLR). Searches were performed in PubMed, Scopus, Scielo and Google Scholar. We used the MESH terms: out-of-pocket, catastrophic health expenditure, health and Colombia. We included cost description or cost analysis studies. Cost-effectiveness analysis of health technologies and qualitative studies were excluded. Data about period of analysis, type of study, costing perspective, OOPE, and CHE were extracted. Studies were classified as macroeconomic, microeconomic, and diseases analysis. All costs were indexed to 2018 and reported in Colombian pesos (COP)

    Chemical composition and antibacterial and antioxidant activity of a citrus essential oil and its fractions

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    ABSTRACT Essential oils (EOs) from Citrus are the main by-product of Citrus-processing industries. In addition to food/beverage and cosmetic applications, citrus EOs could also potentially be used as an alternative to antibiotics in food-producing animals. A commercial citrus EO—Brazilian Orange Terpenes (BOT)—was fractionated by vacuum fractional distillation to separate BOT into various fractions: F1, F2, F3, and F4. Next, the chemical composition and biological activities of BOT and its fractions were characterized. Results showed the three first fractions had a high relative amount of limonene (≥10.86), even higher than the whole BOT. Conversely, F4 presented a larger relative amount of BOT’s minor compounds (carvone, cis-carveol, trans-carveol, cis-p-Mentha-2,8-dien-1-ol, and trans-p-Mentha-2,8-dien-1-ol) and a very low relative amount of limonene (0.08–0.13). Antibacterial activity results showed F4 was the only fraction exhibiting this activity, which was selective and higher activity on a pathogenic bacterium (E. coli) than on a beneficial bacterium (Lactobacillus sp.). However, F4 activity was lower than BOT. Similarly, F4 displayed the highest antioxidant activity among fractions (equivalent to BOT). These results indicated that probably those minor compounds that detected in F4 would be more involved in conferring the biological activities for this fraction and consequently for the whole BOT, instead of the major compound, limonene, playing this role exclusively

    PIH11 out-of-pocket health expenditures related to prenatal care: evidence from Colombia, 2018

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    To estimate the out-of-pocket expenditures (OOPE) and indirect costs related to prenatal check-ups and pregnancy complications in women seen in a maternity hospital in Cartagena-Colombia, 2018. Cost description study. A survey was constructed to estimate OOPE and indirect costs owing to prenatal check-ups. Women were asked about sociodemographic variables. The survey investigated how much pregnant women spend in the care of prenatal check-ups. Also, it explored OOPE linked to pregnancy complications. Productivity losses were quantified from the reduction of work time produced by the prenatal check-up. Absolute and relative frequencies, averages and interquartile ranges (IQR) were used to describe the population and estimate the OOPE and indirect costs in pregnant women. The latter were calculated from the percentile method. We performed a bootstrapping to generate an empirical estimate of the complete sample distribution. Costs were reported in Colombian pesos (COP), 2018. Fifty-six pregnant women were surveyed, with an average age of 25.9 years (±6.2). 96.4% of the respondents had completed at least primary school studies, 7.3% were married. All women surveyed had OOPE in at least one cost-item. Transportation was the item with the highest frequency of expenses. The mean of OOPE for women who attend their prenatal check-up were COP71,736(IQRCOP71,736 (IQR COP53,400-92,715).Twentyfivewomenreportedsomecomplicationrelatedtotheirpregnancystatus.ThemeanOOPEassociatedwithapregnancycomplicationwasCOP92,715). Twenty-five women reported some complication related to their pregnancy status. The mean OOPE associated with a pregnancy complication was COP57,539 (IQR COP28,68628,686-100,124). Women reported a time average of 4.2 hours (range 1-12) for attending the prenatal check-up, and their companions spent 4.5 (range 1-13). On average a woman had productivity losses of COP13,541(IQRCOP13,541 (IQR COP8,138- 16,276)andhercompanionCOP16,276) and her companion COP14,475 (range 8,1308,130-19,531). Expenses produced by prenatal care could totalize 9.2% (6.8-11.9) of the monthly income of a poor household, which unfortunately makes prenatal care an important source of economic burden, impacting poor population in Cartagena

    Influence of adiposity and sex on SARS-CoV-2 antibody response in vaccinated university students: A cross-sectional ESFUERSO study

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    Prior studies have identified various determinants of differential immune responses to COVID-19. This study focused on the Ig-G anti-RBD marker, analyzing its potential correlations with sex, vaccine type, body fat percentage, metabolic risk, perceived stress, and previous COVID-19 exposure. In this study, data (available in S1 Data) were obtained from 108 participants from the ESFUERSO cohort, who completed questionnaires detailing their COVID-19 experiences and stress levels assessed through the SISCO scale. IgG anti-RBD concentrations were quantified using an ELISA assay developed by UNAM. Multiple regression analysis was employed to control for covariates, including sex, age, body fat percentage, body mass index (BMI), and perceived stress. This sample comprised young individuals (average age of 21.4 years), primarily consisting of females (70%), with a substantial proportion reporting a family history of diabetes, hypertension, or obesity. Most students had received the Moderna or Pfizer vaccines, and 91% displayed a positive anti-RBD response. A noteworthy finding was the interaction between body fat percentage and sex. In males, increased adiposity was associated with decreased Ig-G anti-RBD concentration; in females, the response increased. Importantly, this pattern remained consistent regardless of the vaccine received. No significant associations were observed for dietary habits or perceived stress variables. This research reports the impact of sex and body fat percentage on the immune response through Ig-G anti-RBD levels to COVID-19 vaccines. The implications of these findings offer a foundation for educational initiatives and the formulation of preventive policies aimed at mitigating health disparities

    Functionalised peptide hydrogel for the delivery of cardiac progenitor cells.

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    Heart failure (HF) remains one of the leading causes of death worldwide; most commonly developing after myocardial infarction (MI). Since adult cardiomyocytes characteristically do not proliferate, cells lost during MI are not replaced. As a result, the heart has a limited regenerative capacity. There is, therefore, a need to develop novel cell-based therapies to promote the regeneration of the heart after MI. The delivery and retention of cells at the injury site remains a significant challenge. In this context, we explored the potential of using an injectable, RGDSP-functionalised self-assembling peptide - FEFEFKFK - hydrogel as scaffold for the delivery and retention of rat cardiac progenitor cells (CPCs) into the heart. Our results show that culturing CPCs in vitro within the hydrogel for one-week promoted their spontaneous differentiation towards adult cardiac phenotypes. Injection of the hydrogel on its own, or loaded with CPCs, into the rat after injury resulted in a significant reduction in myocardial damage and left ventricular dilation

    Neutralizing anti-RBD fraction for SARS-CoV-2 is associated with the interaction waist circumference and sex. An ESFUERSO preliminary report on university students

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    In a previous study we reported that 25% of college students had a family history of type 2 diabetes (T2D), and 39% of hypertension. Interestingly, between 17 to 47% reported not knowing about T2D or hypertension, neither the existing obesity-metabolic problems (ESFUERSO study). The COVID-19 pandemic forced confinement and modifications in food intake, physical activity, and psychological stress. This study aimed to analyze if the immune Ig-G anti-RBD (protective epitope in S protein) response associated with type of vaccination, metabolic risk, perceived stress, and history of COVID-19 contacts. We included 116 students at the 3th year of follow up in the ESFUERSO cohort at Reynosa. Mean age 21.4 (SD 1.04) years old, BMI 28 (6.6), females 70% (81/116). The serum concentration of Ig-G anti-RGB measured by ELISA adjusted by sex, age, body fat percentage, and BMI was analyzed. Researchers performed a multiple regression analysis with Stata V17.0. We found that 70% of the students had a family history of diabetes, hypertension, and/or obesity at baseline. Only 5 (4%) students did not have any vaccine at the time of the study, 102 (88%) were vaccinated with Moderna or Pfizer and 9 (8%) with other vaccines (Cansino, Sinovac). The prevalence of positive anti-RBD was 91%. The body fat percentage interacted with sex (p=0.034) explaining the serum concentration of anti-RBD decreased as adiposity increases in men, but increased in women. The interaction remained is spite of type of vaccination. We found no differences among metabolic risks for food consumption, distress, uncertainty, lack of sleep, sadness, and anxiety were associated with metabolic problems. Our model predicts neutralizing anti-RBD had multiplicative interaction by sex and body fat percentage (increases in females and decreases in males), with no effects on stress score or food consumption

    A CMOS Morlet Wavelet Generator

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    The design and characterization of a CMOS circuit for Morlet wavelet generation is introduced. With the proposed Morlet wavelet circuit, it is possible to reach a~low power consumption, improve standard deviation (σ) control and also have a small form factor. A prototype in a double poly, three metal layers, 0.5 µm CMOS process from MOSIS foundry was carried out in order to verify the functionality of the proposal. However, the design methodology can be extended to different CMOS processes. According to the performance exhibited by the circuit, may be useful in many different signal processing tasks such as nonlinear time-variant systems

    MINERvA neutrino detector response measured with test beam data

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    The MINERvA collaboration operated a scaled down replica of the solid scintillator tracking and sampling calorimeter regions of the MlNERvA detector in a hadron test beam at the Fermilab Test Beam Facility. This paper reports measurements with samples of protons, pions, and electrons from 0.35 to 2.0 GeV/c momentum. The calorimetric response to protons, pions, and electrons is obtained from these data. A measurement of the parameter in Birks\u27 law and an estimate of the tracking efficiency are extracted from the proton sample. Overall the data are well described by a Geant4-based Monte Carlo simulation of the detector and particle interactions with agreements better than 4% for the calorimetric response, though some features of the data are not precisely modeled. These measurements are used to tune the MINERvA detector simulation and evaluate systematic uncertainties in support of the MINERvA neutrino cross-section measurement program. (C) 2015 Published by Elsevier B.V
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