167 research outputs found

    Diet enrichment with a specific essential free amino acid mixture improves healing of undressed wounds in aged rats

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    Chronic wounds are a major, often underestimated, health problem for the elderly. Standard wound care products are not usuallymanufactured tomeet the increased demand of nutrients by skin cells in order to regenerate new tissue and accelerate healing. This work was therefore undertaken to establish whether wound healing could be accelerated by nutritional supplementation with a specific mixture tailored to human need of essential amino acids (EAAs) without topical medication. To this end, using a skin full-thickness excisional model in aged rats,we compared the closure dynamics of undressing wounds in animals fed an EAAs-enriched diet or standard diet. We assessed the degree of fibrosis and inflammation, as well as relevant signaling molecules such as COL1A1, iNOS and TGFβ1. The results showed wound healing was accelerated in EAAs-fed rats, which was accompanied by reduced inflammation and changes in TGFβ1 and COL1A1 expression. Collectively, our findings indicate that dietary supplementation with balanced EAAs diet could serve as a strategy to accelerate wound healing without inducing fibrosis and could therefore be a simple but pivotal therapeutic approach in human also

    Low-temperature stability and sensing performance of mid-infrared bloch surface waves on a one-dimensional photonic crystal

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    The growing need for new and reliable surface sensing methods is arousing interest in the electromagnetic excitations of ultrathin films, i.e., to generate electromagnetic field distributions that resonantly interact with the most significant quasi-particles of condensed matter. In such a context, Bloch surface waves turned out to be a valid alternative to surface plasmon polaritons to implement high-sensitivity sensors in the visible spectral range. Only in the last few years, however, has their use been extended to infrared wavelengths, which represent a powerful tool for detecting and recognizing molecular species and crystalline structures. In this work, we demonstrate, by means of high-resolution reflectivity measurements, that a one-dimensional photonic crystal can sustain Bloch surface waves in the infrared spectral range from room temperature down to 10 K. To the best of our knowledge, this is the first demonstration of infrared Bloch surface waves at cryogenic temperatures. Furthermore, by exploiting the enhancement of the surface state and the high brilliance of infrared synchrotron radiation, we demonstrate that the proposed BSW-based sensor has a sensitivity on the order of 2.9 cm–1 for each nanometer-thick ice layer grown on its surface below 150 K. In conclusion, we believe that Bloch surface wave-based sensors are a valid new class of surface mode-based sensors for applications in materials science

    Freestanding non-covalent thin films of the propeller-shaped polycyclic aromatic hydrocarbon decacyclene

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    Molecularly thin, nanoporous thin films are of paramount importance in material sciences. Their use in a wide range of applications requires control over their chemical functionalities, which is difficult to achieve using current production methods. Here, the small polycyclic aromatic hydrocarbon decacyclene is used to form molecular thin films, without requiring covalent crosslinking of any kind. The 2.5 nm thin films are mechanically stable, able to be free-standing over micrometer distances, held together solely by supramolecular interactions. Using a combination of computational chemistry and microscopic imaging techniques, thin films are studied on both a molecular and microscopic scale. Their mechanical strength is quantified using AFM nanoindentation, showing their capability of withstanding a point load of 26 ± 9 nN, when freely spanning over a 1 μm aperture, with a corresponding Young’s modulus of 6 ± 4 GPa. Our thin films constitute free-standing, non-covalent thin films based on a small PAH

    Protein Intake and Cognitive Function in Older Adults: A Systematic Review and Meta-Analysis

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    Introduction: The present study investigated the association between protein intake and cognitive function in older adults.Methods: We performed a literature search with no restriction on publication year in MEDLINE, SCOPUS, CINAHL, Age-Line from inception up to October 2020. Observational studies that investigated as a primary or secondary outcome the association of protein intake and cognitive function in older adults aged >= 60 years were included.Results : Nine cross-sectional studies that investigated a total of 4929 older adults were included in the qualitative analysis. Overall cognitive function was examined in 6 studies. Four investigations reported null associations and 2 studies found that older adults with a high protein intake had higher global cognitive function than their counterparts. Results from the meta-analysis suggested that there were no significant associations between protein consumption and global cognitive function in older adults, regardless of gender. Three studies investigated other cognitive domains. Memory and protein intake were significantly and positively correlated in all studies. In addition, visuospatial, verbal fluency, processing speed, and sustained attention were positively associated with protein consumption in 1 study each.Conclusion: No significant associations between protein intake and global cognitive function were observed in neither qualitative nor quantitative analyses. The association between protein consumption with multiple other cognitive domains were also tested. As a whole, 3 studies reported a positive and significant association between high protein intake and memory, while 1 study observed a significant and positive association with visuospatial, verbal fluency, processing speed, and sustained attention

    Body Weight Loss and Tissue Wasting in Late Middle-Aged Mice on Slightly Imbalanced Essential/Non-essential Amino Acids Diet

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    Objective: Inadequate protein intake can impair protein balance thus leading to skeletal muscle atrophy, impaired body growth, and functional decline. Foods provide both non-essential (NEAAs) and essential amino acids (EAAs) that may convey different metabolic stimuli to specific organs and tissues. In this study, we sought to evaluate the impact of six diets, with various EAA/NEAA blends, on body composition and the risk of developing tissue wasting in late middle-aged male mice. Methods: Six groups of late middle-aged male mice were fed for 35 days with iso-nutrients, iso-caloric and iso-nitrogenous special diets containing different EAA/NEAA ratios ranging from 100%/0% to 0%/100%. One group fed with standard laboratory rodent diet (StD) served as control. Preliminarily, we verified the palatability of the diets by recording the mice preference, and by making accessible all diets simultaneously, in comparison to StD. Body weight, food and water consumption were measured every three days. Blood and urine samples, as well as heart, kidneys, liver, spleen, triceps surae, retroperitoneal WAT, and BAT were harvested and weighed. Results: Mice consuming NEAA-based diets, although showing increased food and calorie intake, suffered the most severe weight loss. Interestingly, the diet containing a EAA/NEAA-imbalance, with moderate NEAAs prevalence, was able to induce catabolic stimuli, generalized body wasting and systemic metabolic alterations comparable to those observed with diet containing NEAA alone. In addition, complete depletion of retroperitoneal white adipose tissue and a severe loss (>75%) of brown adipose tissue were observed together with muscle wasting. Conversely, EAA-containing diets induced significant decreases in body weight by reducing primarily fat reserves, but at the same time they improved the clinical parameters. On these basis we can deduce that tissue wasting was caused by altered AA quality, independent of reduced nitrogen or caloric intake. Conclusion: Our results indicate that diets containing an optimized balance of AA composition is necessary for preserving overall body energy status. These findings are particularly relevant in the context of aging and may be exploited for contrasting its negative correlates, including body wasting

    Interaction of Skeletal and Left Ventricular Mass in Older Adults with Low Muscle Performance

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    BACKGROUND: It was recently hypothesized the existence of “cardiac-skeletal muscle axis.” However, the relationship between skeletal muscle mass (SMM) and left ventricular mass (LVM) has never been investigated in the specific group of older individuals with low skeletal mass and physical performance. We tested this hypothesis in the SPRINT-T (Sarcopenia and Physical Frailty IN older people: multicomponenT Treatment strategies Trial) population using LVM as independent variable and SMM as dependent variable. METHODS: SMM was assessed by dual-energy X-ray absorptiometry scan and expressed as appendicular lean mass (ALM), and LVM was estimated through echocardiography. Low ALM was defined according to Foundation for the National Institutes of Health Sarcopenia Project criteria, and Short Physical Performance Battery (SPPB) was used to assess physical performance.RESULTS: The population consisted of 100 persons (33 men and 67 women), aged 70 years or older (mean age = 79 5 years) with low ALM and SPPB ranged between 3 and 9, suggestive of physical frailty. Charlson Comorbidity Index median score was 0. Mean value of LVM was 193 67 g, indexed LVM/body surface area (LVM/BSA) was 112 33 g/m2, and cardiac output (CO) was 65 19 L/min. ALM was strongly and positively correlated with LVM (r = 0.54602; P < .0001), LVM/BSA (r = 0.30761; P < .002), CO (r = 0.49621; P < .0001), body mass index (BMI) (r = 0.52461; P < .0001), sex (r = 0.77; P < .001), fat mass (r = 0.38977; P < .0001), and hemoglobin (Hb) (r = 0.26001; P < .01). In the multivariate analysis, LVM (β = .019 .005; P < .0001), CO (β = .038 .016; P = .019), BMI (β = .286 .051; P < .0001), and Hb (β = .544 .175; P = .0025) remained associated to ALM. CONCLUSIONS: In a sample of older persons with low muscle mass and physical performance, LVM was positively and significantly correlated with ALM, independently from blood pressure, physical activity, and other potential confounders. Future studies are needed to address the effect of interventions targeting LVM and SMM

    Inter-Organelle Membrane Contact Sites and Mitochondrial Quality Control during Aging: A Geroscience View

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    Mitochondrial dysfunction and failing mitochondrial quality control (MQC) are major determinants of aging. Far from being standalone organelles, mitochondria are intricately related with cellular other compartments, including lysosomes. The intimate relationship between mitochondria and lysosomes is reflected by the fact that lysosomal degradation of dysfunctional mitochondria is the final step of mitophagy. Inter-organelle membrane contact sites also allow bidirectional communication between mitochondria and lysosomes as part of nondegradative pathways. This interaction establishes a functional unit that regulates metabolic signaling, mitochondrial dynamics, and, hence, MQC. Contacts of mitochondria with the endoplasmic reticulum (ER) have also been described. ER-mitochondrial interactions are relevant to Ca2+ homeostasis, transfer of phospholipid precursors to mitochondria, and integration of apoptotic signaling. Many proteins involved in mitochondrial contact sites with other organelles also participate to degradative MQC pathways. Hence, a comprehensive assessment of mitochondrial dysfunction during aging requires a thorough evaluation of degradative and nondegradative inter-organelle pathways. Here, we present a geroscience overview on (1) degradative MQC pathways, (2) nondegradative processes involving inter-organelle tethering, (3) age-related changes in inter-organelle degradative and nondegradative pathways, and (4) relevance of MQC failure to inflammaging and age-related conditions, with a focus on Parkinson's disease as a prototypical geroscience condition
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