Concerns have recently grown regarding the safety of iodinated contrast agents used for CTA and CTP imaging. We tested whether the incidence of AN, defined by a >or=25% increase in the post-contrast ...scan creatinine level, was higher among patients with ischemic stroke who underwent a functional contrast-enhanced CT protocol compared with those who had no iodinated contrast administration.
The contrast-exposed group consisted of 575 patients with acute ischemic stroke who underwent CTA (n = 313), CTA/CTP (n = 224), or CTA/CTP followed by conventional angiography (n = 38) within 24 hours of stroke onset and were consecutively enrolled in a prospective cohort study. The nonexposed group consisted of 343 patients with ischemic stroke, consecutively admitted to the same institution, who did not receive iodinated contrast material. Patients were stratified by baseline eGFR. In the primary analysis, the Fisher exact test was used to compare the incidence of AN between the contrast-exposed and the nonexposed patients at 24, 48, and 72 hours and on a cumulative basis. A secondary analysis compared the incidence of AN in patients who underwent conventional angiography following CTA/CTP versus patients who underwent CTA/CTP only.
The incidence of AN was 5% in the exposed and 10% in the nonexposed group (P = .003). Patients who underwent conventional angiography after contrast CT were at no greater risk of AN than patients who underwent CTA/CTP alone (26 patients, 5%; and 2 patients, 5%, respectively; P = .7).
Administration of a contrast-enhanced CT protocol involving CTA/CTP and conventional angiography in selected patients does not appear to increase the incidence of CIN.
Abstract Background Recent studies suggested that advanced glycation end-products (AGEs) and their receptor (RAGE) interaction may be promoted by inflammation and oxidative stress. These processes ...could also contribute to the pathogenesis of atrial fibrillation (AF), but their roles remain poorly defined. We studied the association of AGE–RAGE axis with AF in diabetic and non-diabetic patients, since the axis appears to play a key role in the process. Methods Ninety-seven consecutive outpatients were included in this transversal study. Fifty-nine patients were in sinus rhythm (SR) and 38 in permanent AF. Plasma fluorescent AGEs and soluble RAGE (sRAGE) were measured and comparisons between patients with and without AF were performed. A multivariate logistic regression analysis was made to define the independent factors associated with AF. Results Fluorescent AGEs and sRAGE were higher in AF group (74.9 ± 25.6 vs . 61.8 ± 20.1 a.u. for fluorescent AGEs, p = 0.006; 1714.2 ± 1105.5 vs . 996.1 ± 820.7 pg/mL for sRAGE, p = 0.001). These differences were specially marked in non-diabetic patients. Both AGEs and sRAGE directly correlated with left atrial dimensions ( r = 0.496; r = 0.536 for atrial area and r = 0.491; r = 0.511 for atrial volume, for fluorescent AGEs and sRAGE, respectively, p < 0.001). In a multivariate analysis, fluorescent AGEs and sRAGE resulted as markers of AF independent of left atrial distension, diabetes and other confounding variables. Conclusions AGEs and sRAGE plasma levels were higher in patients with AF, independently of diabetes mellitus , and they positively correlated with atrial dimensions, indicating a role for the AGE–RAGE axis in the arrhythmogenic structural atrial remodelling.
Low-grade chronic inflammation plays a pivotal role among other pathophysiological mechanisms involved in obesity. Innate and adaptive immune cells undergo systemic proinflammatory polarization that ...gives rise to an increased secretion of proinflammatory cytokines, which in turn leads to insulin resistance. Bariatric surgery is currently the most effective treatment for obesity, as it brings on significant weight loss, glucose metabolism improvement, and a decrease in systemic inflammation biomarkers. After bariatric surgery, several changes have been reported to occur in adaptive immunity, including reduction in CD4+ and CD8+ T cell counts, a decrease in the Th1/Th2 ratio, an increase in B regulatory cells, and reduction in proinflammatory cytokine secretion. Overall, there seems to be a major shift in several lymphocyte populations from a proinflammatory to an anti-inflammatory phenotype. Furthermore, increased antioxidant activity and reduced lipid and DNA oxidation products have been reported after bariatric surgery in circulating mononuclear cells. This paper highlights the shift in the adaptive immune system in response to weight loss and improved insulin sensitivity, as well as the interplay between immunological and metabolic adaptations as a result of bariatric surgery. Finally, based on data from research, we propose several mechanisms such as changes in adaptive immune cell phenotypes and their by-products, recruitment in adipose tissue, reduced oxidative stress, and modification in metabolic substrate availability as drivers to reduce low-grade chronic inflammation after bariatric surgery in severe obesity.
Large admission DWI lesion volumes are associated with poor outcomes despite acute stroke treatment. The primary aims of our study were to determine whether CTA collaterals correlate with admission ...DWI lesion volumes in patients with AIS with proximal occlusions, and whether a CTA collateral profile could identify large DWI volumes with high specificity.
We studied 197 patients with AIS with M1 and/or intracranial ICA occlusions. We segmented admission and follow-up DWI lesion volumes, and categorized CTA collaterals by using a 5-point CS system. ROC analysis was used to determine CS accuracy in predicting DWI lesion volumes >100 mL. Patients were dichotomized into 2 categories: CS = 0 (malignant profile) or CS>0. Univariate and multivariate analyses were performed to compare imaging and clinical variables between these 2 groups.
There was a negative correlation between CS and admission DWI lesion volume (ρ = -0.54, P < .0001). ROC analysis revealed that CTA CS was a good discriminator of DWI lesion volume >100 mL (AUC = 0.84, P < .001). CS = 0 had 97.6% specificity and 54.5% sensitivity for DWI volume >100 mL. CS = 0 patients had larger mean admission DWI volumes (165.8 mL versus 32.7 mL, P < .001), higher median NIHSS scores (21 versus 15, P < .001), and were more likely to become functionally dependent at 3 months (95.5% versus 64.0%, P = .003). Admission NIHSS score was the only independent predictor of a malignant CS (P = .007).
In patients with AIS with PAOs, CTA collaterals correlate with admission DWI infarct size. A malignant collateral profile is highly specific for large admission DWI lesion size and poor functional outcome.
Abstract
Polyethylene (PE) is a non-biodegradable polymer and accumulate easily on environment due its high molecular weight. In order to reduce this problem low-density (LDPE), high-density (HDPE) ...and biodegradable (BIO-PE) polyethylene films were exposed to CO
2
laser radiation at different fluences and to domestic composting, the effects of CO
2
laser radiation and domestic composting were characterized by FTIR spectroscopy. LDPE, HDPE and BIO-PE exposed to CO
2
laser radiation underwent thermodegradation reactions causing changes in LDPE, HDPE and BIO-PE chemical and physical properties due to chain scission. LDPE, HDPE and BIO-PE biodegradation reactions leading to the formation of carbonyl (C=O), vinyl (CH2=CH) and hydroxyl (OH) groups.
In this paper two room-temperature ionic liquids (ILs), 1-hexyl-3-methylimidazolium tetrafluroborate HMIMBF
4 and 1-hexyl-3-methylimidazolium hexafluorophosphate HMIMPF
6, have been studied as 1%wt. ...additives of a mineral hydrocracking oil for steel–steel contacts. Rheological properties of the mixtures and base oil were determined over shear rates and temperatures ranging 1–1000
s
−1 and 40–100
°C, respectively. Friction and wear testing was made using a block-on-ring tribometer set for pure sliding contact and XPS was used to analyze wear surfaces. HMIMPF
6 and HMIMBF
4 increased the viscosity of the base oil and decreased friction and wear. Friction and wear reduction are related to reactivity of the anion of the ionic liquids with surfaces forming FeF
3, B
2O
3, and species such as P
2O
5 or PO
4
3−.
In this paper we aim to validate a methodology designed to obtain Hα emission line fluxes from J-PLUS photometric data. J-PLUS is a multi narrow-band filter survey carried out with the 2 deg2 field ...of view T80Cam camera, mounted on the JAST/T80 telescope in the OAJ, Teruel, Spain. The information of the twelve J-PLUS bands, including the J0660 narrow-band filter located at rest-frame Hα, is used over the first 42 deg2 observed to retrieve de-reddened and NII decontaminated Hα emission line fluxes of 46 star-forming regions with previous SDSS and/or CALIFA spectroscopic information. The agreement between the J-PLUS Hα fluxes and those obtained with spectroscopic data is remarkable, finding a median comparison ratio with a scatter of R = F H α J − PLUS / F H α spec = 1.05 ± 0.25 $ \mathcal{R}\,{=}\,F^{\mathrm{J-PLUS}}_{\mathrm{H\alpha}}/F^{\mathrm{spec}}_{\mathrm{H\alpha}}\,{=}\,1.05\,{\pm}\,0.25 $ . This demonstrates that it is possible to retrieve reliable Hα emission line fluxes from J-PLUS photometric data. With an expected area of thousands of square degrees upon completion, the J-PLUS dataset will allow the study of several star formation science cases in the nearby universe, as the spatially resolved star formation rate of nearby galaxies at z ≤ 0.015, and how it is influenced by the environment, morphology, stellar mass, and nuclear activity. As an illustrative example, the close pair of interacting galaxies NGC 3994 and NGC 3995 is analysed, finding an enhancement of the star formation rate not only in the centre, but also in outer parts of the disk of NGC 3994.
There are two alternative, main technologies for removal of nitrogen oxides (NOx) from vehicle exhaust gases, namely, selective catalytic reduction (SCR) and NOx storage and reduction (NSR). The SCR ...technology consists of using ammonia (NH3), produced by hydrolysis of urea that is stored into an on‐board tank in the vehicle, to reduce NOx selectively to nitrogen (N2). In the NSR strategy, the conversion of NOx into N2 occurs through a two‐step cyclic operation. During the fuel‐lean stage, the NOx is trapped on the catalyst; then, the engine is switched to a fuel‐rich condition, under which NOx is released and reduced preferentially to N2, although some NH3 can also be produced. The concept of coupling NSR with SCR is based on tuning the operation of the NSR catalyst to produce a controlled amount of NH3, which is stored on the SCR catalyst during the fuel‐rich stage and used to reduce the remaining NOx on the SCR catalyst, placed downstream of the NSR catalyst in a sequential NSR+SCR configuration. Alternatively, the same concept applies to the dual‐layer architecture, which comprises a SCR layer deposited on top of the NSR layer in a single monolith. The internal generation of NH3 in the NSR catalyst avoids the need of external supply from the on‐board tank, but also achieves impressive NOx‐to‐N2 efficiency, apparently allowing zero‐level pollutant emission.
Combined efforts: A comprehensive overview of the coupling of NOx storage and reduction (NSR) and NH3‐selective catalytic reduction (SCR) catalysts in the architecture of two sequential NSR+SCR monoliths, or alternatively as a dual‐layer NSR–SCR single monolith, is presented. The combination takes advantage of the benefits of individual NSR and SCR technologies, improving the global NOx elimination and maximizing the N2 selectivity, together with the prevention of the ammonia slip.
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