The present work is focused on thermochemical energy storage (TCES) in Concentrated Solar Power (CSP) plants by means of the Calcium-Looping (CaL) process using cheap, abundant and non-toxic natural ...carbonate minerals. CaL conditions for CSP storage involve calcination of CaCO3 in the solar receiver at relatively low temperature whereas carbonation of CaO is carried out at high temperature and high CO2 concentration to use the heat of reaction for power production by means of a CO2 closed power cycle. Under these conditions, large CaO particles derived from limestone to be used in industrial processes are rapidly deactivated due to pore-plugging, which limits the extent of the reaction. This is favored by the relatively small pores of the CaO skeleton generated by low temperature calcination, the large thickness of the CaCO3 layer built upon the CaO surface and the very fast carbonation kinetics. On the other hand, at CaL conditions for CSP storage does not limit carbonation of CaO derived from dolomite (dolime). Dolime is shown to exhibit a high multicycle conversion regardless of particle size, which is explained by the presence of inert MgO grains that allow the reacting gas to percolate inside the porous particles.
Thermochemical Energy storage of CSP using the Calcium-Looping process Display omitted
•CSP can be stored by means of the Calcium-Looping process in thermochemical form.•The CaL process uses cheap, abundant and non-toxic natural calcium carbonate minerals.•These materials may exhibit a high multicycle activity at CaL conditions that maximize the global plant efficiency.•Natural limestone performance is limited by particle size at practical conditions due to pore plugging.•Pore plugging does not pose a significant limitation to the performance of natural dolomite.
Primary aldosteronism is the most common cause of secondary hypertension, most frequently due to an aldosterone-producing adenoma or idiopathic hyperaldosteronism. Somatic mutations of the potassium ...channel KCNJ5 in the region of the selectivity filter have been found in a significant number of aldosterone-producing adenomas. There are also familial forms of primary aldosteronism, one of which, familial hyperaldosteronism type 3 which to date has been found in one family who presented with a severe abnormality in aldosterone and 18-oxocortisol production and hypertrophy and hyperplasia of the transitional zone of the adrenal cortex. In familial hyperaldosteronism type 3, there is a genomic mutation causing a T158A change of amino acids within the selectivity filter region of the KCNJ5 gene.
We are reporting our studies demonstrating that lentiviral-mediated expression of a gene carrying the T158A mutation of the KCNJ5 in the HAC15 adrenal cortical carcinoma cell line causes a 5.3-fold increase in aldosterone secretion in unstimulated HAC15-KCNJ5 cells and that forskolin-stimulated aldosterone secretion was greater than that of angiotensin II. Expression of the mutated KCNJ5 gene decreases plasma membrane polarization, allowing sodium and calcium influx into the cells. The calcium channel antagonist nifedipine and the calmodulin inhibitor W-7 variably inhibited the effect. Overexpression of the mutated KCNJ5 channel resulted in a modest decrease in HAC15 cell proliferation.
These studies demonstrate that the T158A mutation of the KCNJ5 gene produces a marked stimulation in aldosterone biosynthesis that is dependent on membrane depolarization and sodium and calcium influx into the HAC15 adrenal cortical carcinoma cells.
There are two opposing welfare effects of market power in a model with monopolistic competition, loan defaults and moral hazard. The loss of output produced if firms set a higher mark‐up over ...marginal costs confronts with some gain due to higher expected profits and the reduction of defaults. Such tradeoff results in an optimal level of market power that decreases with the efficiency of liquidation following default on a loan. If moral hazard is pervasive, credit rationing cuts down the default rates and mitigates the welfare cost of financial frictions.
Immunotherapies for malignant melanoma seek to boost the anti‐tumoral response of CD8+ T cells, but have a limited patient response rate, in part due to limited tumoral immune cell infiltration. ...Genetic or pharmacological inhibition of the pannexin 1 (PANX1) channel‐forming protein is known to decrease melanoma cell tumorigenic properties in vitro and ex vivo. Here, we crossed Panx1 knockout (Panx1−/−) mice with the inducible melanoma model BrafCA, PtenloxP, Tyr::CreERT2 (BPC). We found that deleting the Panx1 gene in mice does not reduce BRAF(V600E)/Pten‐driven primary tumor formation or improve survival. However, tumors in BPC‐Panx1−/− mice exhibited a significant increase in the infiltration of CD8+ T lymphocytes, with no changes in the expression of early T‐cell activation marker CD69, lymphocyte activation gene 3 protein (LAG‐3) checkpoint receptor, or programmed cell death ligand‐1 (PD‐L1) in tumors when compared to the BPC‐Panx1+/+ genotype. Our results suggest that, although Panx1 deletion does not overturn the aggressive BRAF/Pten‐driven melanoma progression in vivo, it does increase the infiltration of effector immune T‐cell populations in the tumor microenvironment. We propose that PANX1‐targeted therapy could be explored as a strategy to increase tumor‐infiltrating lymphocytes to boost anti‐tumor immunity.
Although the PANX1 channel protein is highly expressed in melanoma, we found that global deletion of Panx1 did not prevent tumor onset, progression, or lymph node invasion in a mouse model of melanoma (Braf/Pten; BPC). However, BPC‐Panx1KO mice displayed splenomegaly and an increase of effector T lymphocytes and granzyme B+ cells (GzmB+) in the melanoma tumor microenvironment.
The Pittsburgh Sleep Quality Index (PSQI) and the Epworth Sleepiness Scale (ESS) are questionnaires used to assess sleep quality and excessive daytime sleepiness in clinical and population-based ...studies. The present study aimed to evaluate the construct validity and factor structure of the PSQI and ESS questionnaires among young adults in four countries (Chile, Ethiopia, Peru and Thailand).
A cross-sectional study was conducted among 8,481 undergraduate students. Students were invited to complete a self-administered questionnaire that collected information about lifestyle, demographic, and sleep characteristics. In each country, the construct validity and factorial structures of PSQI and ESS questionnaires were tested through exploratory and confirmatory factor analyses (EFA and CFA).
The largest component-total correlation coefficient for sleep quality as assessed using PSQI was noted in Chile (r = 0.71) while the smallest component-total correlation coefficient was noted for sleep medication use in Peru (r = 0.28). The largest component-total correlation coefficient for excessive daytime sleepiness as assessed using ESS was found for item 1 (sitting/reading) in Chile (r = 0.65) while the lowest item-total correlation was observed for item 6 (sitting and talking to someone) in Thailand (r = 0.35). Using both EFA and CFA a two-factor model was found for PSQI questionnaire in Chile, Ethiopia and Thailand while a three-factor model was found for Peru. For the ESS questionnaire, we noted two factors for all four countries.
Overall, we documented cross-cultural comparability of sleep quality and excessive daytime sleepiness measures using the PSQI and ESS questionnaires among Asian, South American and African young adults. Although both the PSQI and ESS were originally developed as single-factor questionnaires, the results of our EFA and CFA revealed the multi- dimensionality of the scales suggesting limited usefulness of the global PSQI and ESS scores to assess sleep quality and excessive daytime sleepiness.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The "assessment for learning" movement in education has increased attention to self-grading and peer-grading practices in primary and secondary schools. This research synthesis examined several ...questions pertaining to the use of self-grading and peer-grading in conjunction with criterion-referenced testing in 3rd- through 12th-grade-level classrooms. We investigated (a) the effects of students' participation in grading on subsequent test performance, (b) the difference between grades when assigned by students or teachers, and (c) the correlation between grades assigned by students and teachers. Students who engaged in self-grading performed better (g = .34) on subsequent tests than did students who did not. Moderator analyses suggested that the benefits of self-grading were estimated to be greater when the study controlled for group differences through random assignment. Students who engaged in peer-grading performed better on subsequent tests than did students who did not (g = .29). On average, students did not grade themselves or peers significantly differently than teachers (self-grades, g = .04; peer-grades, g = .04) and showed moderate correlation (self-grading, r = .67; peer-grading, r = .68) with teacher grades. Further, other moderator analyses and examination of studies suggested that self- and peer-grading practices can be implemented to positive effect in primary and secondary schools with the use of rubrics and training for students in a formative assessment environment. However, because of a limited number of studies, these mediating variables need more research to allow more conclusive findings.
Stream interaction regions (SIRs) dominate the large‐scale solar wind dynamics during the minimum of the solar cycle. The interaction of SIRs with the magnetosphere causes most of geomagnetic storms ...during this epoch. We used in‐situ solar wind observations at 1 AU to study 62 SIRs detected in the interval 2007–2008 (minimum of cycle 23) and 61 SIRs in the interval 2018–2019 (minimum of cycle 24). We compared distinct characteristics of SIRs, such as the solar wind streams velocities, the presence of forward and/or reverse shocks (RS), SIR radial widths, the relative position of the stream interface within the SIRs, SIR latitudinal orientation, and the geoeffectiveness. There were more geomagnetic storms driven by SIRs in cycle 23 than in cycle 24. The pattern of fast solar wind streams in cycle 23 tended to be faster than in cycle 24. We found more SIRs with RS in cycle 23 than in cycle 24. For the geoeffective SIRs, the momentum flows from the fast solar wind to the slow solar wind, as well as their stream interface is closer to the SIR front. Coronal holes associated with SIRs registered in cycle 23 tended to be wider in longitude near the solar equator and/or at midlatitudes. We did not find a clear relation between the geoeffectiveness of the SIRs and their latitudinal inclinations.
Key Points
Stream interaction regions at 1 AU had different characteristics in solar cycle minimum 23 and 24
We found differences in their patterns of solar wind streams, the presence of shock waves, and the relative position of their stream interface
Stream interaction regions were more geoeffective in the minimum of solar cycle 23 than in the minimum of cycle 24
Context:Approximately half of primary aldosteronism (PA) have clinically evident disease according to clinical (hypertension) and/or laboratory (aldosterone and renin levels) findings but do not have ...nodules detectable in routine cross-sectional imaging. However, the detailed histopathologic, steroidogenic and pathobiological features of cross-sectional image negative PA have not been well characterized.Objective:Examine histopathology, steroidogenic enzyme expression and somatic mutation status of aldosterone-driver genes in adrenals from cross-sectional image negative hyperaldosteronism.Methods:25 cross-sectional image negative cases were retrospectively reviewed. In situ adrenal aldosterone production capacity was determined using immunohistochemistry (IHC) of steroidogenic enzymes. Somatic mutation status of aldosterone-driver genes (ATP1A1, ATP2B3, CACNA1D and KCNJ5) was determined in the CYP11B2 immunopositive areas (n=35, micronodule: n=32, ZG: n=3) using next-generation sequencing (NGS) after macrodissection.Results:25 cases were classified as multiple adrenocortical micronodules (MN, n=13) or diffuse hyperplasia of zona glomerulosa (DH, n=12) based upon histopathological evaluation and CYP11B2 IHC. Somatic mutations in aldosterone-driver genes were detected in 21 of 26 (81%) of CYP11B2-positive cortical micronodules in MN, with 17 (65%) mutations in CACNA1D, two (8%) in KCNJ5, and one each (4% each) in ATP1A1 and ATP2B). One of six (17%) of nodules in DH harbored somatic aldosterone-driver gene mutations (in CACNA1D), however no mutations were detected in CYP11B2-positive non-nodular DH areas.Conclusion:Morphologic evaluation and CYP11B2 IHC enabled the classification of cross-sectional image negative hyperaldosteronism into MN and DH. Somatic mutations driving renin-independent aldosterone production are common in micronodules of MN, suggesting the novel histological entity possibly related to APCC development.
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In the recent decades, various controlled delivery systems have been introduced with the aim to improve solubility, stability and bioavailability of poorly absorbed drugs. Among all, ...lipid nanoparticles gather interesting properties as drug or gene delivery carriers. These systems, composed either of solid lipids (SLN) or of solid and liquid lipids (NLC) stabilized with surfactants, combine the advantages of other colloidal particles such as polymeric nanoparticles, fat emulsions and liposomes avoiding their main disadvantages. Lipid nanoparticles represent an interesting approach for eye drug delivery as they can improve the corneal absorption of drugs enhancing their bioavailability. The Generally Recognized as Safe status of formulation excipients, the scaling-up facilities and the possibility of sterilization, make them suitable for industrial production. In this review, the latest findings, potential applications, and challenges related to the use of lipid nanoparticles for ocular drug delivery are comprehensively discussed.
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