Right ventricular failure (RVF) is a major cause of morbidity and mortality after left ventricular assist device (LVAD) implantation. The pulmonary artery pulsatility index (PAPi) is a novel ...hemodynamic index that predicts RVF in the setting of myocardial infarction, although it has not been shown to predict RVF after LVAD implantation.
We performed a retrospective, single-center analysis to examine the utility of the PAPi in predicting RVF and RV assist device (RVAD) implantation in 85 continuous-flow LVAD recipients. We performed a multivariate logistic regression analysis incorporating previously identified predictors of RVF after LVAD placement, including clinical and echocardiographic variables, to determine the independent effect of PAPi in predicting RVF or RVAD after LVAD placement.
In this cohort, the mean PAPi was 3.4 with a standard deviation of 2.9. RVF occurred in 33% of patients, and 11% required a RVAD. Multivariate analysis, adjusting for age, blood urea nitrogen (BUN), and Interagency Registry for Mechanically Assisted Circulatory Support profile, revealed that higher PAPi was independently associated with a reduced risk of RVAD placement (odds ratio OR, 0.30; 95% confidence interval CI, 0.07-0.89). This relationship did not change significantly when echocardiographic measures were added to the analysis. Stratifying the analysis by the presence of inotropes during catheterization revealed that PAPi was more predictive of RVAD requirement when measured on inotropes (OR, 0.21; 95% CI, 0.02-0.97) than without (OR, 0.49; 95% CI, 0.01-1.94). Furthermore, time from catheterization to LVAD did not significantly affect the predictive value of the PAPi (maximum time, 6 months). Receiver operating characteristic curve analysis revealed that optimal sensitivity and specificity were achieved using a PAPi threshold of 2.0.
In LVAD recipients, the PAPi is an independent predictor of RVF and the need for RVAD support after LVAD implantation. This index appears more predictive in patients receiving inotropes and was not affected by time from catheterization to LVAD in our cohort.
Silver (Ag) clusters confined in matrices possess remarkable luminescence properties, but little is known about their structural and electronic properties. We characterized the bright green ...luminescence of Ag clusters confined in partially exchanged Ag-Linde Type A (LTA) zeolites by means of a combination of x-ray excited optical luminescence-extended x-ray absorption fine structure, time-dependent-density functional theory calculations, and time-resolved spectroscopy. A mixture of tetrahedral Ag
(H
O)
(
= 2 and
= 4) clusters occupies the center of a fraction of the sodalite cages. Their optical properties originate from a confined two-electron superatom quantum system with hybridized Ag and water O orbitals delocalized over the cluster. Upon excitation, one electron of the s-type highest occupied molecular orbital is promoted to the p-type lowest unoccupied molecular orbitals and relaxes through enhanced intersystem crossing into long-lived triplet states.
Proposed changes to the United Network for Organ Sharing heart transplant allocation protocol will prioritize patients receiving temporary mechanical circulatory support (tMCS), including ...extracorporeal membrane oxygenation (ECMO), percutaneous ventricular assist devices (PVADs), and intra-aortic balloon pumps (IABPs). We sought to evaluate contemporary trends in the incidence and outcomes of patients who required tMCS during the hospitalization before heart transplantation.
Using the National Inpatient Sample from 1998 to 2014, we identified 6,892 patients who received an orthotopic heart transplant and classified them by pre-transplant ECMO, PVAD, or IABP placement or no pre-transplant tMCS. We compared baseline characteristics and in-hospital outcomes between patients who underwent pre-transplant ECMO, PVAD, or IABP and patients who did not receive tMCS before heart transplantation.
Of patients who underwent heart transplantation, 456 (6.6%) received tMCS before transplant. During the study period, the use of tMCS more than doubled, from 17 cases per year from 1998 to 2002 to 40 cases per year from 2012 to 2014 (p < 0.001 for trend). Of patients with tMCS, 341 (74.8%) were supported by IABP, 130 (28.5%) were supported by ECMO, and 21 (4.6%) were supported by PVAD. Before 2007, patients who required tMCS had higher in-hospital mortality than patients who did not require tMCS before transplant (14.3% vs 7.5%, p = 0.05). In the subsequent era (2007 to 2014), mortality was not significantly different (4.7% vs 5.1%, p = 0.9). Hospital mortality improved over time for all patients but most significantly in patients who required tMCS (9.6% absolute risk reduction). However, patients who received tMCS had increased lengths of stays and rates of acute renal, hepatic, and respiratory failure, sepsis, bleeding complications, and surgical reoperations.
The use of tMCS before cardiac transplantation is increasing, with no difference in in-patient post-transplant mortality in the recent era between patients who did and did not receive tMCS but with increased complication rates among those who received tMCS. These data support the use of tMCS before cardiac transplantation in appropriately selected patients. Clinicians should balance the above outcomes when making decisions to implant tMCS, given the impending changes to the United Network for Organ Sharing heart allocation protocol.
A zeroth-order, non-diffracting Bessel beam, generated by picosecond laser pulses (1064 nm, 10 Hz, 30 ps) through an axicon, was utilized to perform pulse energy-dependent (12 mJ, 16 mJ, 20 mJ, 24 ...mJ) laser ablation of silver (Ag) substrates in air. The fabrication resulted in finger-like Ag nanostructures (NSs) in the sub-200 nm domain and obtained structures were characterized using the FESEM and AFM techniques. Subsequently, we employed those Ag NSs in surface-enhanced Raman spectroscopy (SERS) studies achieving promising sensing results towards trace-level detection of six different hazardous materials (explosive molecules of picric acid (PA) and ammonium nitrate (AN), a pesticide thiram (TH) and the dye molecules of Methylene Blue (MB), Malachite Green (MG), and Nile Blue (NB)) along with a biomolecule (hen egg white lysozyme (HEWL)). The remarkably superior plasmonic behaviour exhibited by the AgNS corresponding to 16 mJ pulse ablation energy was further explored. To accomplish a real-time application-oriented understanding, time-dependent studies were performed utilizing the AgNS prepared with 16 mJ and TH molecule by collecting the SERS data periodically for up to 120 days. The coated AgNSs were prepared with optimized gold (Au) deposition, accomplishing a much lower trace detection in the case of thiram (~50 pM compared to ~50 nM achieved prior to the coating) as well as superior EF up to ~108 (~106 before Au coating). Additionally, these substrates have demonstrated superior stability compared to those obtained before Au coating.
Deep-eutectic solvents (DESs) are used as a promising alternative to aqueous solutions for the recovery of valuable metals from NdFeB magnets. A deep-eutectic solvent based on choline chloride and ...lactic acid (molar ratio 1 : 2) was used for the leaching of rare earths and other metals from NdFeB magnets. A process for the separation of Fe, B and Co from Nd and Dy in the deep-eutectic solvent was developed by using the ionic liquid tricaprylmethylammonium thiocyanate (Aliquat 336 SCN, A336SCN) diluted in toluene (0.9 M). The extraction parameters were optimized and stripping of B was efficiently carried out by HCl, while EDTA was employed for the recovery of Fe and Co. The separation of Nd and Dy was assessed by using two different types of extractants, a mixture of trialkylphosphine oxides (Cyanex 923) and bis(2-ethylhexyl)phosphoric acid (D2EHPA). Based on the distribution ratios, separation factors and the ease of subsequent stripping, Cyanex 923 was chosen as the most effective extractant. The purified Dy present in the less polar phase was easily recovered by stripping with water, while the Nd present in the deep-eutectic solvent was recovered by precipitation stripping with a stoichiometric amount of oxalic acid. Nd 2 O 3 and Dy 2 O 3 were recovered with a purity of 99.87% and 99.94%, respectively. The feasibility to scale up this separation process was corroborated by a setup of mixer-settlers and highlighted by the possibility to fully recover and reuse the deep-eutectic solvent and the less polar phases employed in the extractions. The new proposed system based on a deep-eutectic solvent combined with traditional organic extraction phases presented higher selectivities and efficiencies than the analogous aqueous system. Extended X-ray absorption fine structure (EXAFS) was employed to elucidate the different mechanisms for extraction of Co and Fe from the deep-eutectic solvent and from an aqueous solution.
The reactivity of Fe(II) sorbed on clay edges towards U(VI) reduction is investigated at pH 6.0 using Fe-free synthetic montmorillonite (MONT), Fe-poor natural montmorillonite (Fe-MONT) and Fe-rich ...natural nontronite (NAu-2). Partial reduction of U(VI) by sorbed Fe(II) only occurred on MONT but neither on Fe-MONT nor NAu-2. In the former case, the formation of a hydrated uranyl silicate (soddyite)-like phase is demonstrated by U L
III
-edge EXAFS spectroscopy.
57
Fe Mössbauer spectrometry reveals that in this case 10% of the total sorbed Fe(II) was oxidized before- and an additional 6% after-addition of U(VI). The lack of reactivity towards U(VI) of Fe(II) sorbed on Fe-MONT or NAu-2 is likely due to inter-valence charge transfer (IVCT) between surface Fe(II) and structural Fe(III). The present study demonstrates that the reactivity of clay sorbed Fe
2+
towards U(VI) strongly depends on the nature of clay and correspondingly on the oxidation state of sorbed Fe.
Graphical abstract
Despite its benefits, the extraction of rare earths (REEs) from chloride solutions with neutral or basic extractants is not efficient, so that separation is currently carried out by using acidic ...extractants. This work aims to improve this process by replacing the conventional molecular diluents in the organic phase by ionic liquids (ILs) which contain coordinating anions. The extraction of La(iii), Ce(iii) and Pr(iii) from concentrated chloride solutions was tested with a quaternary ammonium and a phosphonium nitrate IL extractant. Dissolution of a trialkylphosphine oxide neutral extractant (Cyanex 923) in the nitrate ILs changed the preference of the organic phase from lighter to heavier REE and increased the overall extraction efficiency and the loading capacity of the organic phase. An increase of the CaCl
concentration in the feed solution resulted in higher extraction efficiencies, due to a lower activity of water and hence to a poorer hydration of the REE ions. In that respect, chloride ions were not coordinating to the REE ion after extraction from concentrated chloride solutions. To achieve selectivity, one should fine-tune the loading by varying the CaCl
and/or Cyanex 923 concentrations. Adjustment of the CaCl
concentration in the feed and stripping solutions is essential for the separation of mixtures of REE. However, and unlike in the case of acidic extractants, no control of equilibrium pH is required. The split-anion extraction offers the possibility to separate mixtures of REEs in different groups without having to change the chloride feed solution. It leads to safer and environmentally friendlier extraction processes by (1) using solvents that are not volatile, not flammable and do no accumulate static electricity, (2) consuming no acids or alkali, (3) easy stripping with water and (4) avoidance to create nitrate-containing effluents.
Hamartoma of mature cardiac myocytes (HMCM) is a rare, benign cardiac tumor. We report a case of a 19-year-old female with an atypical presentation, including significant weight loss and abnormal ...electrocardiogram. A transthoracic echocardiogram (TTE) revealed a mass causing left ventricular outflow tract (LVOT) obstruction, confirmed by cardiac magnetic resonance (CMR) imaging showing a 5 x 3 cm mass contiguous with the right ventricular free wall and exhibiting heterogeneous, diffuse late gadolinium enhancement. The patient subsequently underwent sternotomy for surgical biopsy and septal myectomy, with histology of the mass being consistent with HMCM. The patient remained asymptomatic during her 6-month follow-up.
Bacillus benzeovorans assisted and supported growth of ruthenium (bio-Ru) and palladium/ruthenium (bio-Pd@Ru) core@shell nanoparticles (NPs) as bio-derived catalysts. Characterization of the bio-NPs ...using various electron microscopy techniques and high-angle annular dark field (HAADF) analysis confirmed two NP populations (1-2 nm and 5-8 nm), with core@shells in the latter. The Pd/Ru NP lattice fringes, 0.231 nm, corresponded to the (110) plane of RuO
While surface characterization using X-ray photoelectron spectroscopy (XPS) showed the presence of Pd(0), Pd(II), Ru(III) and Ru(VI), X-ray absorption (XAS) studies of the bulk material confirmed the Pd speciation (Pd(0) and Pd(II)- corresponding to PdO), and identified Ru as Ru(III) and Ru(IV). The absence of Ru-Ru or Ru-Pd peaks indicated Ru only exists in oxide forms (RuO
and RuOH), which are surface-localized. X ray diffraction (XRD) patterns did not identify Pd-Ru alloying. Preliminary catalytic studies explored the conversion of 5-hydroxymethyl furfural (5-HMF) to the fuel precursor 2,5-dimethyl furan (2,5-DMF). Both high-loading (9.7 wt.% Pd, 6 wt.% Ru) and low-loading (2.4 wt.% Pd, 2 wt.% Ru) bio-derived catalysts demonstrated high conversion efficiencies (~95%) and selectivity of ~63% (~20% better than bio-Ru NPs) and 58%, respectively. These materials show promising future scope as efficient low-cost biofuel catalysts.
Deep eutectic solvents (DESs) based on choline chloride, chromium chloride, and their mixtures with water are emerging as one of the most promising sustainable alternatives to the banned and ...carcinogenic Cr(
vi
) electroplating process (REACH Annex XVII). However, the coordination chemistry of these liquids is still largely unresolved and only a limited number of compositions have been studied to date. Hence, an in-depth study using a large range of techniques was carried out on the complete composition range of stable liquids at room temperature. This resulted in detailed knowledge regarding the concentration profiles of all constituting components, and the discovery of an important link between the coordination chemistry and the conductivity of the mixtures. Additionally, a tool was developed to obtain 10 different variables and concentrations by the measurement of a single UV/Vis absorption spectrum. Based on these results, researchers in both industry and academia will be able to select a certain DES-water mixture to obtain specific characteristics, as well as concentrations of the constituting components and complexes. Additionally, these mixtures can be closely monitored before, during and after electroplating, by means of UV/Vis absorption spectroscopy. These results form an important step towards the industrial application of these promising green electrolytes as alternatives to the wide-spread and recently banned carcinogenic Cr(
vi
) electroplating baths.
A sustainable Cr(
iii
) electrolyte was brought one step closer to industrial application by in-depth understanding of the (coordination) chemistry.
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