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961.
Enriqueta Antic Ruben Vera Francisco Vzquez Cludia Fonts Changyong Lu Josep Ros 《Materials》2021,14(4)
Nanoparticle-doped polymer inclusion membranes (NP-PIMs) have been prepared and characterized as new materials for the removal of arsenate and phosphate from waters. PIMs are made of a polymer, cellulose triacetate (CTA), and an extractant, which interacts with the compound of interest. We have used the ionic liquid (IL) trioctylmethylammonium chloride (Aliquat 336) as the extractant and have investigated how the addition of nanoparticles can modify membrane properties. To this end, inorganic nanoparticles, such as ferrite (Fe3O4), SiO2 and TiO2, and multiwalled carbon nanotubes (MWCNTs), were blended with the polymer/extractant mixture. Scanning electron microscopy (SEM), infrared spectroscopy (FT-IR), and contact angle measurements have been used to characterize the material. Moreover, PIM stability was checked by measuring the mass loss during the experiments. Since Aliquat 336 acts as an anion exchanger, the NP-PIMs have been explored in two different applications: (i) as sorbent materials for the extraction of arsenate and phosphate anions; (ii) as an organic phase for the separation of arsenate and phosphate in a three-phase system. The presence of oleate-coated ferrite NP in the PIM formulation represents an improvement in the efficiency of NP-PIMs used as sorbents; nevertheless, a decrease in the transport efficiency for arsenate but not for phosphate was obtained. The ease with which the NP-PIMs are prepared suggests good potential for future applications in the treatment of polluted water. Future work will address three main aspects: firstly, the implementation of the Fe3O4-PIMs for the removal of As(V) in real water containing complex matrices; secondly, the study of phosphate recovery with other cell designs that allow large volumes of contaminated water to be treated; and thirdly, the investigation of the role of MWCNTs in PIM stability. 相似文献
962.
963.
David Martinez-Gomez Francisco B. Ortega Mark Hamer Esther Lopez-Garcia Ellen Struijk Kabir P. Sadarangani Carl J. Lavie Fernando Rodríguez-Artalejo 《Mayo Clinic proceedings. Mayo Clinic》2019,94(11):2209-2219
ObjectiveTo examine the association between physical activity (PA) and the risk for metabolically unhealthy obesity (MUO) or metabolically healthy obesity (MHO) in Asian adults.Patients and MethodsData were obtained from 205,745 healthy individuals 18 years or older. Individuals were classified as inactive, lower or upper insufficiently active, active, and high active. Metabolically unhealthy was defined as having 1 or more of the metabolic syndrome criteria, excluding the abdominal obesity criterion.ResultsThe percentages of metabolically healthy normal-weight (MHNW), metabolically healthy overweight (MHOW), MHO, and MUO in our cohort were 30.8% (63,408 of 205,745), 5.8% (12,002 of 205,745), 4.1% (8329 of 205,745), and 20.7% (42,564 of 205,745), respectively. During a mean follow-up of 6 (range, 0.5-19) years, among 63,408 MHNW participants, 1890 (3.0%) and 1174 (1.9%) developed MUO and MHO, respectively. Among 12,002 MHOW participants, 3404 (28.4%) developed MUO and 2734 (22.8%) developed MHO. A total of 5506 of 8329 (66.1%) participants moved from MHO to MUO, and 5675 of 42,564 (13.3%) moved from MUO to MHO. Compared with being inactive, MHNW individuals who were active or high active showed lower risk for MUO. Among those with MHOW, being high active was associated with reduced risk for MUO and MHO. Although among MHO participants, PA was not associated with incident MUO, being active or high active was linked to a greater likelihood of moving from MUO to MHO.ConclusionPA may prevent the development of both MHO and MUO. PA also helps increase the transition from MUO to MHO, which may contribute to reduce the subsequent development of type 2 diabetes mellitus and major cardiovascular disease complications. 相似文献
964.
965.
Benefits of Rhythm Control and Rate Control in Recent‐onset Atrial Fibrillation: The HERMES‐AF Study
966.
Luis David Alcaraz Gabriela Olmedo Germán Bonilla René Cerritos Gustavo Hernández Alfredo Cruz Enrique Ramírez Catherine Putonti Beatriz Jiménez Eva Martínez Varinia López Jacqueline L. Arvizu Francisco Ayala Francisco Razo Juan Caballero Janet Siefert Luis Eguiarte Jean-Philippe Vielle Octavio Martínez Valeria Souza Alfredo Herrera-Estrella Luis Herrera-Estrella 《Proceedings of the National Academy of Sciences of the United States of America》2008,105(15):5803-5808
The Cuatro Ciénegas Basin (CCB) in the central part of the Chihuahan desert (Coahuila, Mexico) hosts a wide diversity of microorganisms contained within springs thought to be geomorphological relics of an ancient sea. A major question remaining to be answered is whether bacteria from CCB are ancient marine bacteria that adapted to an oligotrophic system poor in NaCl, rich in sulfates, and with extremely low phosphorus levels (<0.3 μM). Here, we report the complete genome sequence of Bacillus coahuilensis, a sporulating bacterium isolated from the water column of a desiccation lagoon in CCB. At 3.35 Megabases this is the smallest genome sequenced to date of a Bacillus species and provides insights into the origin, evolution, and adaptation of B. coahuilensis to the CCB environment. We propose that the size and complexity of the B. coahuilensis genome reflects the adaptation of an ancient marine bacterium to a novel environment, providing support to a “marine isolation origin hypothesis” that is consistent with the geology of CCB. This genomic adaptation includes the acquisition through horizontal gene transfer of genes involved in phosphorous utilization efficiency and adaptation to high-light environments. The B. coahuilensis genome sequence also revealed important ecological features of the bacterial community in CCB and offers opportunities for a unique glimpse of a microbe-dominated world last seen in the Precambrian. 相似文献
967.
Aims/hypothesis. Alterations in the regulation of gene expression could be involved in the development of Type II (non-insulin-dependent) diabetes mellitus.¶Methods. We compared the mRNA concentrations of eight genes encoding proteins involved in insulin action and intermediary metabolism in skeletal muscle of healthy volunteers and Type II diabetic patients. The in vivo regulation of the expression of these genes was investigated after 5 days of hypocaloric diet (1045 kJ/day).¶Results. In the basal state, diabetic muscle showed reduced insulin receptor (–38 %), hexokinase II (–73 %), glycogen synthase (–45 %) and lipoprotein lipase (–70 %) mRNA expression. There was no difference in the mRNA abundances of IRS-1, GLUT 4, p85α phosphatidylinositol-3-kinase (p85αPI3K) or Rad. In both groups, caloric restriction induced weight loss, reduced glycaemia and increased plasma ketone body concentrations. The diet also increased plasma concentrations of fatty acids and decreased whole-body insulin sensitivity in control subjects. In control subjects, the diet increased p85αPI3K ( + 146 %), insulin receptor ( + 100 %) and Rad ( + 40 %) mRNA concentrations in muscle. In Type II diabetic patients, the diet increased insulin receptor ( + 41 %) and Rad ( + 31 %) mRNAs but the expression of p85αPI3K was not modified.¶Conclusion/interpretation. The regulation of the expression of p85αPI3K is altered during caloric restriction in skeletal muscle of Type II diabetic patients. Because we have shown in an earlier study that there is also a defective regulation of p85αPI3K gene expression in response to insulin, these data support the hypothesis that alterations in the regulation of gene expression could be involved in the pathogenesis of Type II diabetes. [Diabetologia (2000) 43: 356–363] 相似文献
968.
In situ activation of the type 2 ryanodine receptor in pancreatic beta cells requires cAMP-dependent phosphorylation 总被引:2,自引:0,他引:2
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Md. Shahidul Islam Ingo Leibiger Barbara Leibiger Daniela Rossi Vincenzo Sorrentino Tomas J. Ekstrm Hkan Westerblad Francisco H. Andrade Per-Olof Berggren 《Proceedings of the National Academy of Sciences of the United States of America》1998,95(11):6145-6150
Molecular mechanisms that regulate in situ activation of ryanodine receptors (RY) in different cells are poorly understood. Here we demonstrate that caffeine (10 mM) released Ca2+ from the endoplasmic reticulum (ER) in the form of small spikes in only 14% of cultured fura-2 loaded beta cells from ob/ob mice. Surprisingly, when forskolin, an activator of adenylyl cyclase was present, caffeine induced larger Ca2+ spikes in as many as 60% of the cells. Forskolin or the phosphodiesterase-resistant PKA activator Sp-cAMPS alone did not release Ca2+ from ER. 4-Chloro-3-ethylphenol (4-CEP), an agent that activates RYs in other cell systems, released Ca2+ from ER, giving rise to a slow and small increase in [Ca2+]i in beta cells. Prior exposure of cells to forskolin or caffeine (5 mM) qualitatively altered Ca2+ release by 4-CEP, giving rise to Ca2+ spikes. In glucose-stimulated beta cells forskolin induced Ca2+ spikes that were enhanced by 3,9-dimethylxanthine, an activator of RYs. Analysis of RNA from islets and insulin-secreting βTC-3-cells by RNase protection assay, using type-specific RY probes, revealed low-level expression of mRNA for the type 2 isoform of the receptor (RY2). We conclude that in situ activation of RY2 in beta cells requires cAMP-dependent phosphorylation, a process that recruits the receptor in a functionally operative form. 相似文献
969.
Oxytocin (OT) inhibits the uptake of serotonin (5HT) into uterine mast cells. This may modulate 5HT bioavailability in the
myometrium. Because 5HT is an important endogenous uterotonic compound, it has been postulated that this effect of OT may
contribute to its potency as a labor inducer. This also predicts the presence of oxytocin receptors (OTRs) and transducing
signals that will interact with 5HT transporters (SERT) in mast cells. In this study, OTR and SERT were characterized in murine
peritoneal mast cells by radioligandbinding studies. Saturation assays for OTR showed no changes in K
d
along the estrous cycle (6.95±2.76 nM in estrus and 4.07±1.73 nM in diestrus) but an increase in B
max in estrus (0.71±0.08 pmol/106 cells and 0.37±0.05 pmol/106 cells in estrus and diestrus, respectively). B
max and K
d
for SERT were not affected along the estrous cycle.
The signaling between the OTR and the SERT was analyzed by measuring the extent of inhibition of OT and PMA (activator of
protein kinase C on 5HT uptake and the capability of Ro318220 (specific inhibitor of PKC) to increase 5HT uptake and block
the effect of the above compounds in mast cells. The results showed that in murine peritoneal mast cells in vitro (1) ovarian
hormones modulate OTR but not SERT expression, (2) the magnitude of OT action on 5HT uptake depends on the number of OTRs
expressed in mast cells, and (3) the signaling between OTR and the SERT is mediated through the activation of protein kinase
C. It is concluded that the ovarian hormones have a modulatory action on 5HT uptake which involves OT-mediated mechanism. 相似文献
970.