2,094 research outputs found
A robotics platform for automated batch fabrication of high density, microfluidics-based DNA microarrays, with applications to single cell, multiplex assays of secreted proteins
Microfluidics flow-patterning has been utilized for the construction of chip-scale miniaturized DNA and protein barcode arrays. Such arrays have been used for specific clinical and fundamental investigations in which many proteins are assayed from single cells or other small sample sizes. However, flow-patterned arrays are hand-prepared, and so are impractical for broad applications. We describe an integrated robotics/microfluidics platform for the automated preparation of such arrays, and we apply it to the batch fabrication of up to eighteen chips of flow-patterned DNA barcodes. The resulting substrates are comparable in quality with hand-made arrays and exhibit excellent substrate-to-substrate consistency. We demonstrate the utility and reproducibility of robotics-patterned barcodes by utilizing two flow-patterned chips for highly parallel assays of a panel of secreted proteins from single macrophage cells
Collage Concert
Kennesaw State University School of Music presents the 3rd annual Collage Concert.https://digitalcommons.kennesaw.edu/musicprograms/1592/thumbnail.jp
John O. Newton Correspondence
Entries include brief biographical information, a typed biographical letter, and a handwritten letter of correspondence on plain paper
N+3 Small Commercial Efficient and Quiet Transportation for Year 2030-2035
This study develops a future scenario that enables convenient point-to-point commercial air travel via a large network of community airports and a new class of small airliners. A network demand and capacity study identifies current and future air travel demands and the capacity of this new network to satisfy these demands. A current technology small commercial airliner is defined to meet the needs of the new network, as a baseline for evaluating the improvement brought about by advanced technologies. Impact of this new mode of travel on the infrastructure and surrounding communities of the small airports in this new N+3 network are also evaluated. Year 2030-2035 small commercial airliner technologies are identified and a trade study conducted to evaluate and select those with the greatest potential for enhancing future air travel and the study metrics. The selected advanced air vehicle concept is assessed against the baseline aircraft, and an advanced, but conventional aircraft, and the study metrics. The key technologies of the selected advanced air vehicle are identified, their impact quantified, and risk assessments and roadmaps defined
Age-related endothelial dysfunction in human skeletal muscle feed arteries: the role of free radicals derived from mitochondria in the vasculature
Aim
This study sought to determine the role of free radicals derived from mitochondria in the vasculature in the recognized age-related endothelial dysfunction of human skeletal muscle feed arteries (SMFAs). Methods
A total of 44 SMFAs were studied with and without acute exposure to the mitochondria-targeted antioxidant MitoQ and nitric oxide synthase (NOS) blockade. The relative abundance of proteins from the electron transport chain, phosphorylated (p-) to endothelial (e) NOS ratio, manganese superoxide dismutase (MnSOD) and the mitochondria-derived superoxide () levels were assessed in SMFA. Endothelium-dependent and endothelium-independent SMFA vasodilation was assessed in response to flow-induced shear stress, acetylcholine (ACh) and sodium nitroprusside (SNP). Results
MitoQ restored endothelium-dependent vasodilation in the old to that of the young when stimulated by both flow (young: 68 ± 5; old: 25 ± 7; old + MitoQ 65 ± 9%) and ACh (young: 97 ± 4; old: 59 ± 10; old + MitoQ: 98 ± 5%), but did not alter the initially uncompromised, endothelium-independent vasodilation (SNP). Compared to the young, MitoQ in the old diminished the initially elevated mitochondria-derived levels and appeared to attenuate the breakdown of MnSOD. Furthermore, MitoQ increased the ratio of p-eNOS to NOS and the restoration of endothelium-dependent vasodilation in the old by MitoQ was ablated by NOS blockade. Conclusion
This study demonstrated that MitoQ reverses age-related vascular dysfunction by what appears to be an NO-dependent mechanism in human SMFAs. These findings suggest that mitochondria-targeted antioxidants may have utility in terms of counteracting the attenuated blood flow and vascular dysfunction associated with advancing age
Polymicrobial oral biofilm models: simplifying the complex
Over the past century, numerous studies have used oral biofilm models to investigate growth kinetics, biofilm formation, structure and composition, antimicrobial susceptibility and host–pathogen interactions. In vivo animal models provide useful models of some oral diseases; however, these are expensive and carry vast ethical implications. Oral biofilms grown or maintained in vitro offer a useful platform for certain studies and have the advantages of being inexpensive to establish and easy to reproduce and manipulate. In addition, a wide range of variables can be monitored and adjusted to mimic the dynamic environmental changes at different sites in the oral cavity, such as pH, temperature, salivary and gingival crevicular fluid flow rates, or microbial composition. This review provides a detailed insight for early-career oral science researchers into how the biofilm models used in oral research have progressed and improved over the years, their advantages and disadvantages, and how such systems have contributed to our current understanding of oral disease pathogenesis and aetiology
TRPV1 channels in human skeletal muscle feed arteries: implications for vascular function
New Findings
What is the central question of this study?
We sought to determine whether human skeletal muscle feed arteries (SFMAs) express TRPV1 channels and what role they play in modulating vascular function.
What is the main finding and its importance?
Human SMFAs do express functional TRPV1 channels that modulate vascular function, specifically opposing α-adrenergic receptor-mediated vasocontraction and potentiating vasorelaxation, in an endothelium-dependent manner, as evidenced by the α1-receptor-mediated responses. Thus, the vasodilatory role of TRPV1 channels, and their ligand capsaicin, could be a potential therapeutic target for improving vascular function. Additionally, given the ‘sympatholytic’ effect of TRPV1 activation and known endogenous activators (anandamide, reactive oxygen species, H+, etc.), TRPV1 channels might contribute to functional sympatholysis during exercise.
To examine the role of the transient receptor potential vanilloid type 1 (TRPV1) ion channel in the vascular function of human skeletal muscle feed arteries (SMFAs) and whether activation of this heat-sensitive receptor could be involved in modulating vascular function, SMFAs from 16 humans (63 ± 5 years old, range 41–89 years) were studied using wire myography with capsaicin (TRPV1 agonist) and without (control). Specifically, phenylephrine (α1-adrenergic receptor agonist), dexmedetomidine (α2-adrenergic receptor agonist), ACh and sodium nitroprusside concentration–response curves were established to assess the role of TRPV1 channels in α-receptor-mediated vasocontraction as well as endothelium-dependent and -independent vasorelaxation, respectively. Compared with control conditions, capsaicin significantly attenuated maximal vasocontraction in response to phenylephrine [control, 52 ± 8% length–tensionmax (LTmax) and capsaicin, 21 ± 5%LTmax] and dexmedetomidine (control, 29 ± 12%LTmax and capsaicin, 2 ± 3%LTmax), while robustly enhancing maximal vasorelaxation with ACh (control, 78 ± 8% vasorelaxation and capsaicin, 108 ± 13% vasorelaxation) and less clearly enhancing the sodium nitroprusside response. Denudation of the endothelium greatly attenuated the maximal ACh-induced vasorelaxation equally in the control and capsaicin conditions (∼17% vasorelaxation) and abolished the attenuating effect of capsaicin on the maximal phenylephrine response (denuded + capsaicin, 61 ± 20%LTmax). Immunohistochemistry identified a relatively high density of TRPV1 channels in the endothelium compared with the smooth muscle of the SMFAs, but because of the far greater volume of smooth muscle, total TRPV1 protein content was not significantly attenuated by denudation. Thus, SMFAs ubiquitously express functional TRPV1 channels, which alter vascular function, in terms of α1-receptors, in a predominantly endothelium-dependent manner, conceivably contributing to the functional sympatholysis and unveiling a therapeutic target
Further development of the talent development environment questionnaire for sport.
Given the significance of monitoring the critical environmental factors that facilitate athlete performance, this two-phase research aimed to validate and refine the revised Talent Development Environment Questionnaire (TDEQ). The TDEQ is a multidimensional self-report scale that assesses talented athletes’ environmental experiences. Study 1 (the first phase) involved the examination of the revised TDEQ through an exploratory factor analysis (n = 363). This exploratory investigationidentified a 28-item five-factor structure (i.e., TDEQ-5) with adequate internal consistency. Study 2 (the second phase) examined the factorial structure of the TDEQ-5, including convergent validity, discriminant validity, and group invariance (i.e., gender and sports type). The second phase was carried out with 496 talented athletes through the application of confirmatory factor analyses and multigroup invariance tests. The results supported the convergent validity, discriminant validity, and group invariance of the TDEQ-5. In conclusion, the TDEQ-5 with 25 items appears to be a reliable and valid scale for use in talent development environments
Vascular mitochondrial respiratory function: the impact of advancing age
Little is known about vascular mitochondrial respiratory function and the impact of age. Therefore, skeletal muscle feed arteries were harvested from young (33 ± 7 yr, n = 10), middle-aged (54 ± 5 yr, n = 10), and old (70 ± 7 yr, n = 10) subjects, and mitochondrial respiration as well as citrate synthase (CS) activity were assessed. Complex I (CI) and complex I + II (CI+II) state 3 respiration were greater in young (CI: 10.4 ± 0.8 pmol·s−1·mg−1 and CI+II: 12.4 ± 0.8 pmol·s−1·mg−1, P \u3c 0.05) than middle-aged (CI: 7 ± 0.6 pmol·s−1·mg−1 and CI+II: 8.3 ± 0.5 pmol·s−1·mg−1) and old (CI: 7.2 ± 0.4 pmol·s−1·mg−1 and CI+II: 7.6 ± 0.5 pmol·s−1·mg−1) subjects and, as in the case of complex II (CII) state 3 respiration, were inversely correlated with age [r = −0.56 (CI), r = −0.7 (CI+II), and r = 0.4 (CII), P \u3c 0.05]. In contrast, state 4 respiration and mitochondria-specific superoxide levels were not different across groups. The respiratory control ratio was greater in young (2.2 ± 0.2, P \u3c 0.05) than middle-aged and old (1.4 ± 0.1 and 1.1 ± 0.1, respectively) subjects and inversely correlated with age (r = −0.71, P \u3c 0.05). As CS activity was inversely correlated with age (r = −0.54, P \u3c 0.05), when normalized for mitochondrial content, the age-related differences and relationships with state 3 respiration were ablated. In contrast, mitochondrion-specific state 4 respiration was now lower in young (15 ± 1.4 pmol·s−1·mg−1·U CS−1, P \u3c 0.05) than middle-aged and old (23.4 ± 3.6 and 27.9 ± 3.4 pmol·s−1·mg−1·U CS−1, respectively) subjects and correlated with age (r = 0.46, P \u3c 0.05). Similarly, superoxide/CS levels were lower in young (0.07 ± 0.01) than old (0.19 ± 0.41) subjects and correlated with age (r = 0.44, P \u3c 0.05). Therefore, with aging, vascular mitochondrial respiratory function declines, predominantly as a consequence of falling mitochondrial content. However, per mitochondrion, aging likely results in greater mitochondrion-derived oxidative stress, which may contribute to age-related vascular dysfunction
Vasodilatory and vascular mitochondrial respiratory function with advancing age: evidence of a free radically mediated link in the human vasculature
Recognizing the age-related decline in skeletal muscle feed artery (SMFA) vasodilatory function, this study examined the link between vasodilatory and mitochondrial respiratory function in the human vasculature. Twenty-four SMFAs were harvested from young (35 ± 6 yr, n = 9) and old (71 ± 9 yr, n = 15) subjects. Vasodilation in SMFAs was assessed, by pressure myography, in response to flow-induced shear stress, acetylcholine (ACh), and sodium nitroprusside (SNP) while mitochondrial respiration was measured, by respirometry, in permeabilized SMFAs. Endothelium-dependent vasodilation was significantly attenuated in the old, induced by both flow (young: 92 ± 3, old: 45 ± 4%) and ACh (young: 92 ± 3, old: 54 ± 5%), with no significant difference in endothelium-independent vasodilation. Complex I and I + II state 3 respiration was significantly lower in the old (CI young: 10.1 ± 0.8, old: 7.0 ± 0.4 pmol·s−1·mg−1; CI + II young: 12.3 ± 0.6, old: 7.6 ± 0.4 pmol·s−1·mg−1). The respiratory control ratio (RCR) was also significantly attenuated in the old (young: 2.2 ± 0.1, old: 1.1 ± 0.1). Furthermore, state 3 (CI + II) and 4 respiration, as well as RCR, were significantly correlated (r = 0.49–0.86) with endothelium-dependent, but not endothelium-independent, function. Finally, the direct intervention with mitochondrial-targeted antioxidant (MitoQ) significantly improved endothelium-dependent vasodilation in the old but not in the young. Thus, the age-related decline in vasodilatory function is linked to attenuated vascular mitochondrial respiratory function, likely by augmented free radicals
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