Arterial hypertension is a common condition worldwide and an important predictor of several complicated diseases. Arterial hypertension can be triggered by many factors, including physiological, ...genetic, and lifestyle causes. Specifically, molecules of the renin-angiotensin-aldosterone system not only play important roles in the control of blood pressure, but they are also associated with the genesis of arterial hypertension, thus constituting a need for pharmacological interventions. Chronic high pressure generates mechanical damage along the vascular system, heart, and kidneys, which are the principal organs affected in this condition. In addition to mechanical stress, hypertension-induced oxidative stress, chronic inflammation, and the activation of reparative mechanisms lead to end-organ damage, mainly due to fibrosis. Clinical trials have demonstrated that renin-angiotensin-aldosterone system intervention in hypertensive patients lowers morbidity/mortality and inflammatory marker levels as compared to placebo patients, evidencing that this system controls more than blood pressure. This review emphasizes the detrimental effects that a renin-angiotensin-aldosterone system (RAAS) imbalance has on health considerations above and beyond high blood pressure, such as fibrotic end-organ damage.
Explanations for immigrant health outcomes often invoke culture through the use of the concept of acculturation. The over reliance on cultural explanations for immigrant health outcomes has been the ...topic of growing debate, with the critics’ main concern being that such explanations obscure the impact of structural factors on immigrant health disparities. In this paper, we highlight the shortcomings of cultural explanations as currently employed in the health literature, and argue for a shift from individual culture-based frameworks, to perspectives that address how multiple dimensions of inequality intersect to impact health outcomes. Based on our review of the literature, we suggest specific lines of inquiry regarding immigrants’ experiences with day-to-day discrimination, as well as on the roles that place and immigration policies play in shaping immigrant health outcomes. The paper concludes with suggestions for integrating intersectionality theory in future research on immigrant health.
► Cultural explanations for immigrant health outcomes obscure the impact of structural factors on immigrant health. ► A stronger emphasis on how place, racialization processes, and immigration policies impact immigrant health is necessary. ► We recommend an intersectional approach to the study of immigrant health. ► We suggest specific lines of inquiry regarding immigrants' experiences with racism and anti-immigrant policies, and their health impact. ► Interpreting available immigration-related measures requires fuller theorizing as to their context-specific meaning.
We have designed and synthesized an isoreticular series of luminescent metal–organic frameworks (LMOFs) by incorporating a strongly emissive molecular fluorophore and functionally diverse colinkers ...into Zn-based structures. The three-dimensional porous networks of LMOF-261, -262, and -263 represent a unique/new type of nets, classified as a 2-nodal, (4,4)-c net (mot-e type) with 4-fold, class IIIa interpenetration. All compounds crystallize in a body-centered tetragonal crystal system (space group I41/a). A systematic study has been implemented to analyze their interactions with heavy metals. LMOF-263 exhibits impressive water stability, high porosity, and strong luminescence, making it an excellent candidate as a fluorescent chemical sensor and adsorbent for aqueous contaminants. It is extremely responsive to toxic heavy metals at a parts per billion level (3.3 ppb Hg2+, 19.7 ppb Pb2+) and demonstrates high selectivity for heavy metals over light metals, with detection ratios of 167.4 and 209.5 for Hg2+/Ca2+ and Hg2+/Mg2+, respectively. Mixed-metal adsorption experiments also show that LMOF-263 selectively adsorbs Hg2+ over other heavy metal ions in addition to light metals. The Pb2+ KSV value for LMOF-263 (55,017 M–1) is the highest among LMOFs reported to date, and the Hg2+ KSV value is the second highest (459,446 M–1). LMOF-263 exhibits a maximum adsorption capacity of 380 mg Hg2+/g. The Hg2+ adsorption process follows pseudo-second-order kinetics, removing 99.1% of the metal within 30 min. An in situ XPS study provides insight to help understand the interaction mechanism between Hg2+ and LMOF-263. No other MOFs have demonstrated such a high performance in both the detection and the capture of Hg2+ from aqueous solution.
Probiotics, prebiotics and synbiotics have been suggested as dietary strategies to improve intestinal barrier function. This study aimed to assess the effect of two weeks synbiotic supplementation on ...intestinal permeability under basal and stressed conditions. Secondary aims were the assessment of two weeks synbiotic supplementation on systemic immune function and gastrointestinal symptoms including defecation pattern.
Twenty healthy adults completed a double-blind, controlled, randomized, parallel design study.
Groups either received synbiotic (1.5 × 1010 CFU Ecologic® 825 + 10 g fructo-oligosaccharides (FOS P6) per day) or control supplements for two weeks.
Intestinal segment specific permeability was assessed non-invasively by oral administration of multiple sugar probes and, subsequently, assessing the excretion of these probes in urine. This test was conducted at baseline and at the end of intervention, in the absence and in the presence of an indomethacin challenge. Indomethacin was applied to induce a compromised gut state. Plasma zonulin, cytokines and chemokines were measured at baseline and at the end of intervention. Gastrointestinal symptoms and stool frequency were recorded at baseline and daily during intervention.
Significantly more male subjects were in the synbiotic group compared to the control group (P = 0.025). Indomethacin significantly increased urinary lactulose/rhamnose ratio versus without indomethacin, both in the control group (P = 0.005) and in the synbiotic group (P = 0.017). Urinary sugar recoveries and ratios, plasma levels of zonulin, cytokines and chemokines, and gastrointestinal symptom scores were not significantly different after control or synbiotic intervention. Stool frequency within the synbiotic group was significantly increased during synbiotic intervention compared to baseline (P = 0.039) and higher compared to control intervention (P = 0.045).
Two weeks Ecologic® 825/FOS P6 supplementation increased stool frequency, but did not affect intestinal permeability neither under basal nor under indomethacin-induced stressed conditions, immune function or gastrointestinal symptoms in healthy adults.
This paper reports experimental and computational studies on the mechanism of a rhodium-catalyzed hydroformylation that is selective for branched aldehyde products from unbiased alkene substrates. ...This highly unusual selectivity relies on a phospholane–phosphite ligand prosaically called BOBPHOS. Kinetic studies using in situ high pressure IR (HPIR) and the reaction progress kinetic analysis methodology suggested two steps in the catalytic cycle were involved as turnover determining. Negative order in CO and positive orders in alkene and H2 were found and the effect of hydrogen and carbon monoxide partial pressures on selectivity were measured. Labeling studies found rhodium hydride addition to the alkene to be largely irreversible. Detailed spectroscopic HPIR and NMR characterization of activated rhodium-hydrido dicarbonyl species were carried out. In the absence of H2, reaction of the rhodium-hydrido dicarbonyl with allylbenzene allowed further detailed spectroscopic characterization of four- and five-coordinate rhodium-acyl species. Under single-turnover conditions, the ratios of branched to linear acyl species were preserved in the final ratios of aldehyde products. Theoretical investigations uncovered unexpected stabilizing CH−π interactions between the ligand and substrate which influenced the high branched selectivity by causing potentially low energy pathways to become unproductive. Energy span and degree of TOF control analysis strongly support experimental observations and mechanistic rationale. A three-dimensional quadrant model was built to represent the structural origins of regio- and enantioselectivity.
Acute myocardial infarction (AMI) and the heart failure that often follows, are major causes of death and disability worldwide. As such, new therapies are required to limit myocardial infarct (MI) ...size, prevent adverse left ventricular (LV) remodeling, and reduce the onset of heart failure following AMI. The inflammatory response to AMI, plays a critical role in determining MI size, and a persistent pro-inflammatory reaction can contribute to adverse post-MI LV remodeling, making inflammation an important therapeutic target for improving outcomes following AMI. In this article, we provide an overview of the multiple players (and their dynamic roles) involved in the complex inflammatory response to AMI and subsequent LV remodeling, and highlight future opportunities for targeting inflammation as a therapeutic strategy for limiting MI size, preventing adverse LV remodeling, and reducing heart failure in AMI patients.
Evidence suggests that, despite their lower socio-economic status, certain health outcomes are better for first-generation Mexican immigrants than their US-born counterparts. Socio-cultural ...explanations for this apparent epidemiological paradox propose that culture-driven health behaviors and social networks protect the health of the first generation and that, as immigrants acculturate, they lose these health-protecting factors. However, the prominence granted to acculturation within these explanations diverts attention from structural and contextual factors, such as social and economic inequalities, that could affect the health of immigrants and their descendants. The aim of this study is to offer a conceptual redirection away from individual-centered acculturation models towards a more complex understanding of immigrant adaptation in health research. To this end, 40 qualitative in-depth interviews were conducted with first- and second-generation Mexican immigrant women in Southeastern Michigan. The women's narratives highlighted a key process linked to their integration into US society, in which the second generation experienced a more pervasive and cumulative exposure to “othering” than the first generation. The findings point to “othering” and discrimination as potential pathways through which the health of immigrants and their descendants erodes. The paper concludes by proposing a conceptual model that locates “othering” processes within a structural framework, and by drawing implications for research on immigrant health and on discrimination and health.
Recent, compelling evidence indicates that kisspeptins, the products of KiSS‐1 gene, and their receptor GPR54, represent key elements in the neuroendocrine control of reproduction, and that they act ...primarily by regulating gonadotrophin‐releasing hormone (GnRH) secretion at the hypothalamus. Conversely, and despite earlier reports showing GPR54 expression in the pituitary, the potential physiological roles of kisspeptins at this gland have remained elusive. To clarify this issue, cultures of rat pituitary cells were used to evaluate expression of KiSS‐1 and GPR54, and to monitor the ability of kisspeptin‐10 to stimulate Ca2+ responses in gonadotrophs and to elicit luteinising hormone (LH) secretion in vitro. The results obtained show that both GPR54 and KiSS‐1 are expressed in the pituitary of peripubertal male and female rats. Moreover, kisspeptin‐10 induced a rise in free cytosolic Ca2+ concentration (Ca2+i) in approximately 10% of male rat pituitary cells. Intriguingly, kisspeptin‐responsive cells included not only gonadotrophs, in which a 62.8 ± 16.0%Ca2+i rise was observed, but also somatotrophs, wherein kisspeptin induced a 60.3 ± 5.5%Ca2+i increase. Accordingly, challenge of dispersed pituitary cells with increasing kisspeptin‐10 concentrations induced dose‐related LH and growth hormone (GH) secretory responses, which were nevertheless of lower magnitude than those evoked by the primary regulators GnRH and GH‐releasing hormone, respectively. In particular, 10−8 M kisspeptin caused maximal increases in LH release (218.7 ± 23.6% and 180.4 ± 7.2% in male and female rat pituitary cells, respectively), and also stimulated maximally GH secretion (181.9 ± 14.9% and 260.2 ± 15.9% in male and female rat pituitary cells, respectively). Additionally, moderate summation of kisspeptin‐ and GnRH‐induced LH responses was observed after short‐term incubation of male rat pituitary cells. In conclusion, our results provide unequivocal evidence that kisspeptins exert direct pituitary effects in peripubertal male and female rats and suggest a possible autocrine/paracrine mode of action. The precise relevance and underlying mechanisms of this potential new actions of kisspeptins (i.e. the direct modulation of gonadotrophic and somatotrophic axis at the pituitary) deserve further analysis.
Understanding and controlling water stability of MOF-74 Zuluaga, Sebastian; Fuentes-Fernandez, Erika M. A; Tan, Kui ...
Journal of materials chemistry. A, Materials for energy and sustainability,
01/2016, Volume:
4, Issue:
14
Journal Article
Peer reviewed
Open access
Metal organic framework (MOF) materials in general, and MOF-74 in particular, have promising properties for many technologically important processes. However, their instability under humid conditions ...severely restricts practical use. We show that this instability and the accompanying reduction of the CO
2
uptake capacity of MOF-74 under humid conditions originate in the water dissociation reaction H
2
O → OH + H at the metal centers. After this dissociation, the OH groups coordinate to the metal centers, explaining the reduction in the MOF's CO
2
uptake capacity. This reduction thus strongly depends on the catalytic activity of MOF-74 towards the water dissociation reaction. We further show that-while the water molecules themselves only have a negligible effect on the crystal structure of MOF-74-the OH and H products of the dissociation reaction significantly weaken the MOF framework and lead to the observed crystal structure breakdown. With this knowledge, we propose a way to suppress this particular reaction by modifying the MOF-74 structure to increase the water dissociation energy barrier and thus control the stability of the system under humid conditions.
The H
2
O → OH + H reaction poisons the metal centers and starts the degradation of the crystal structure of MOF-74.
Over a six-month trial, growth performance of juvenile tilapia Oreochromis niloticus, raised under biofloc cultivation, was recorded. Five treatments with three replicates and 237 juveniles per ...replicate at different C:N ratios were tested (10:1, 12.5:1, 15:1, 17.5:1, 20:1). Molasses was added every fourth day as the carbon source. Trials were performed in eighteen 3.14m3 circular tanks with constant aeration. Survival in all treatments with biofloc was similar and significantly higher (94.60±2.03%) than in the control treatment (84.96±1.53%). Best weight gain (g/day) occurred in the control treatment, but was influenced by low density. The 10:1 and 15:1 C:N treatments had similar weight gains, but not the 12.5:1 and 17.5:1 C:N treatments. Total production in the 10:1 ratio treatment was the highest (18.03±0.25kgm−3), with slightly declining production, in this order: control (17.86±0.16), 15:1 (17.73±0.18), 12.5:1 (17.20±0.28), 17.5:1 (16.44±0.04), and 20:1 (16.28±0.02). Water quality remained similar in all biofloc treatments, but lower concentrations of nitrogen compounds occurred in the 10:1 C:N ratio tanks. These results suggest a 10:1 C:N ratio provides good survival and growth of tilapia with no water exchange. Biofloc technology is a good strategy in areas where alkaline pH is a limiting factor for aquaculture activities because the pH decreases gradually as molasses is added.
The success and permanence of aquaculture sector relies on the implementation of sustainable and environment-friendly technology, the BFT optimizes energy and resources during production, so our results contribute significantly to the sector.
•Five C:N ration were evaluated in tilapia intensive culture.•Survival in all treatments with biofloc was higher than control treatment.•10:1 C:N ratio stimulated high production over the other treatments.•Ammonium and alkaline pH was reduced in biofloc culture.
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