Kinetic Isotope Effect as a Tool To Investigate the Oxygen Reduction Reaction on Pt-based Electrocatalysts - Part II: Effect of Platinum Dispersion.

We investigated the oxygen reduction reaction (ORR) mechanism on Pt nanoparticles (NPs) dispersed on several carbon blacks with various physicochemical properties (i. e. specific surface ranging from 80 to 900 m2 g-1 , different graphitization degree, etc.). Using the kinetic isotope effect (KIE) along with various electrochemical characterizations, we determined that the rate determining step (RDS) of the ORR is a proton-independent step when the density of Pt NPs on the surface of the carbon support is high. Upon decrease of the density of Pt NPs on the surface, the RDS of the ORR starts involving a proton, as denoted by an increase of the KIE >1. This underlined the critical role played by the carbon support in the oxygen reduction reaction electrocatalysis by Pt supported on high surface area carbon.

Factors associated with inappropriate intravenous antibiotic prescription in patients discharged from the emergency department.

WHAT IS KNOWN AND OBJECTIVE: Since 2011, a collaborative territorial network for urgent care has been deployed in Hospital de la Santa Creu i Sant Pau area, which allows direct and early transfer of patients with frailty from the hospital emergency department (ED) to other healthcare settings according to the destination's adequacy. This study aimed to identify factors associated with inappropriate intravenous antibiotic treatment prescribed on referral of patients with frailty based on microbiological culture and analyse the effect of inappropriate prescription on ED reconsultations for any cause 30 days after hospital discharge. METHODS: This observational, retrospective study was performed at a tertiary hospital between March 2018 and February 2019 and included 264 patients. A multivariate analysis, including variables with a P-value <.2 in the previous univariate analysis, was conducted. The variables included in the analysis were age, sex, patient comorbidities (COPD, diabetes and chronic kidney disease), antibiotic treatment in the last 30 days and patient referral (nursing home or family home). RESULTS AND DISCUSSION: Multidrug-resistant bacteria were isolated from 85 patients (51.5% of the isolates). In total, 159 patients received carbapenem, of whom 87 (54.7%) had non-drug-resistant bacteria. The antibiotic was considered inappropriate in 33 patients (12.5%) according to an antibiogram. Only 71 (26.8%) patients had a definitive culture on discharge. Moreover, 73 (28.3%) patients were readmitted after 30 days. Patients with an inappropriate antibiotic treatment had more reconsultations within 30 days than those with adequate treatment (59.3% vs 24.5%; P < .001). In a multivariate analysis, an inappropriate prescription was significantly associated with a higher number of reconsultations at 30 days (OR, 3.22 [1.37-7.57]). WHAT IS NEW AND CONCLUSION: In patients discharged from the ED with intravenous antibiotics, the empirical prescription of an inappropriate drug according to the final culture is a frequent problem and is related to a higher number of reconsultations. This highlights the need to implement early communication strategies with outpatient units to optimize antibiotic therapy once microbiological results are known.

A morphological database for 606 Colombian bird species.

Colombia is the country with the highest bird diversity in the world. Despite active research in ornithology, compelling morphological information of most bird species is still sparse. However, morphological information is the baseline to understand how species respond to environmental variation and how ecosystems respond to species loss. As part of a national initiative, the Instituto Alexander von Humboldt in collaboration with 12 Colombian institutions and seven biological collections, measured up to 15 morphological traits of 9,892 individuals corresponding to 606 species: 3,492 from individuals captured in field and 6,400 from museum specimens. Species measured are mainly distributed in high Andean forest, páramo, and wetland ecosystems. Seven ornithological collections in Colombia and 18 páramo complexes throughout Colombia were visited from 2013 to 2015. The morphological traits involved measurements from bill (total and exposed culmen, bill width and depth), wing (length, area, wingspan, and the distance between longest primary and longest secondary), tail (length and shape), tarsus (length), hallux (length and claw hallux), and mass. The number of measured specimens per species was variable, ranging from 1 to 321 individuals with a median of four individuals per species. Overall, this database gathered morphological information for >30% of Colombian bird diversity. No copyright, proprietary, or cost restrictions apply; the data should be cited appropriately when used.

Power generation in microbial fuel cells using platinum group metal-free cathode catalyst: Effect of the catalyst loading on performance and costs.

Platinum group metal-free (PGM-free) catalyst with different loadings was investigated in air breathing electrodes microbial fuel cells (MFCs). Firstly, the electrocatalytic activity towards oxygen reduction reaction (ORR) of the catalyst was investigated by rotating ring disk electrode (RRDE) setup with different catalyst loadings. The results showed that higher loading led to an increased in the half wave potential and the limiting current and to a further decrease in the peroxide production. The electrons transferred also slightly increased with the catalyst loading up to the value of ≈3.75. This variation probably indicates that the catalyst investigated follow a 2x2e- transfer mechanism. The catalyst was integrated within activated carbon pellet-like air-breathing cathode in eight different loadings varying between 0.1 mgcm-2 and 10 mgcm-2. Performance were enhanced gradually with the increase in catalyst content. Power densities varied between 90 ± 9 µWcm-2 and 262 ± 4 µWcm-2 with catalyst loading of 0.1 mgcm-2 and 10 mgcm-2 respectively. Cost assessments related to the catalyst performance are presented. An increase in catalyst utilization led to an increase in power generated with a substantial increase in the whole costs. Also a decrease in performance due to cathode/catalyst deterioration over time led to a further increase in the costs.

Enhancement of microbial fuel cell performance by introducing a nano-composite cathode catalyst.

Iron aminoantipyrine (Fe-AAPyr), graphene nanosheets (GNSs) derived catalysts and their physical mixture Fe-AAPyr-GNS were synthesized and investigated as cathode catalysts for oxygen reduction reaction (ORR) with the activated carbon (AC) as a baseline. Fe-AAPyr catalyst was prepared by Sacrificial Support Method (SSM) with silica as a template and aminoantipyrine (AAPyr) as the organic precursor. 3D-GNS was prepared using modified Hummers method technique. The Oxygen Reduction Reaction (ORR) activity of these catalysts at different loadings was investigated by using rotating ring disk (RRDE) electrode setup in the neutral electrolyte. The performance of the catalysts integrated into air-breathing cathode was also investigated. The co-presence of GNS (2 mg cm-2) and Fe-AAPyr (2 mg cm-2) catalyst within the air-breathing cathode resulted in the higher power generation recorded in MFC of 235 ±â€¯1 µW cm-2. Fe-AAPyr catalyst itself showed high performance (217 ±â€¯1 µW cm-2), higher compared to GNS (150 ±â€¯5 µW cm-2) while AC generated power of roughly 104 µW cm-2.

Bimetallic platinum group metal-free catalysts for high power generating microbial fuel cells.

M1-M2-N-C bimetallic catalysts with M1 as Fe and Co and M2 as Fe, Co, Ni and Mn were synthesized and investigated as cathode catalysts for oxygen reduction reaction (ORR). The catalysts were prepared by Sacrificial Support Method in which silica was the template and aminoantipyrine (AAPyr) was the organic precursor. The electro-catalytic properties of these catalysts were investigated by using rotating ring disk (RRDE) electrode setup in neutral electrolyte. Fe-Mn-AAPyr outperformed Fe-AAPyr that showed higher performances compared to Fe-Co-AAPyr and Fe-Ni-AAPyr in terms of half-wave potential. In parallel, Fe-Co-AAPyr, Co-Mn-AAPyr and Co-Ni-AAPyr outperformed Co-AAPyr. The presence of Co within the catalyst contributed to high peroxide production not desired for efficient ORR. The catalytic capability of the catalysts integrated in air-breathing cathode was also verified. It was found that Co-based catalysts showed an improvement in performance by the addition of second metal compared to simple Co- AAPyr. Fe-based bimetallic materials didn't show improvement compared to Fe-AAPyr with the exception of Fe-Mn-AAPyr catalyst that had the highest performance recorded in this study with maximum power density of 221.8 ± 6.6 µWcm-2. Activated carbon (AC) was used as control and had the lowest performances in RRDE and achieved only 95.6 ± 5.8 µWcm-2 when tested in MFC.

Baroreflex activity through the analysis of the cardio-respiratory variability influence over blood pressure in cardiomyopathy patients.

A large portion of the elderly population are affected by cardiovascular diseases. Early prognosis of cardiomyopathies remains a challenge. The aim of this study was to classify cardiomyopathy patients by their etiology based on significant indexes extracted from the characterization of the baroreflex mechanism in function of the influence of the cardio-respiratory activity over the blood pressure. Forty-one cardiomyopathy patients (CMP) classified as ischemic (ICM-24 patients) and dilated (DCM-17 patients) were considered. In addition, thirty-nine control (CON) subjects were used as reference. The beat-to-beat (BBI) time series, from the electrocardiographic (ECG) signal, the systolic (SBP), and diastolic (DBP) time series, from the blood pressure signal (BP), and the respiratory time (TT), from the respiratory flow (RF) signal, were extracted. The three-dimensional representation of the cardiorespiratory and vascular activities was characterized geometrically, by fitting a polygon that contains 95% of data, and by statistical descriptive indices. DCM patients presented specific patterns in the respiratory response to decreasing blood pressure activity. ICM patients presented more stable cardiorespiratory activity in comparison with DCM patients. In general, CMP shown limited ability to regulate changes in blood pressure. In addition, patients also shown a limited ability of their cardiac and respiratory systems response to regulate incremental changes of the vascular variability and a lower heart rate variability. The best classifiers were used to build support vector machine models. The optimal model to classify ICM versus DCM patients achieved 92.7% accuracy, 94.1% sensitivity, and 91.7% specificity. When comparing CMP patients and CON subjects, the best model achieved 86.2% accuracy, 82.9% sensitivity, and 89.7% specificity. When comparing ICM patients and CON subjects, the best model achieved 88.9% accuracy, 87.5% sensitivity, and 89.7% specificity. When comparing DCM patients and CON subjects, the best model achieved 87.5% accuracy, 76.5% sensitivity, and 92.3% specificity. In conclusion, this study introduced a new method for the classification of patients by their etiology based on new indices from the analysis of the baroreflex mechanism.

Selection of Mexican Medicinal Plants by Identification of Potential Phytochemicals with Anti-Aging, Anti-Inflammatory, and Anti-Oxidant Properties through Network Analysis and Chemoinformatic Screening.

Many natural products have been acquired from plants for their helpful properties. Medicinal plants are used for treating a variety of pathologies or symptoms. The axes of many pathological processes are inflammation, oxidative stress, and senescence. This work is focused on identifying Mexican medicinal plants with potential anti-oxidant, anti-inflammatory, anti-aging, and anti-senescence effects through network analysis and chemoinformatic screening of their phytochemicals. We used computational methods to analyze drug-like phytochemicals in Mexican medicinal plants, multi-target compounds, and signaling pathways related to anti-oxidant, anti-inflammatory, anti-aging, and anti-senescence mechanisms. A total of 1373 phytochemicals are found in 1025 Mexican medicinal plants, and 148 compounds showed no harmful functionalities. These compounds displayed comparable structures with reference molecules. Based on their capacity to interact with pharmacological targets, three clusters of Mexican medicinal plants have been established. Curatella americana, Ximenia americana, Malvastrum coromandelianum, and Manilkara zapota all have anti-oxidant, anti-inflammatory, anti-aging, and anti-senescence effects. Plumeria rubra, Lonchocarpus yucatanensis, and Salvia polystachya contained phytochemicals with anti-oxidant, anti-inflammatory, anti-aging, and anti-senescence reported activity. Lonchocarpus guatemalensis, Vallesia glabra, Erythrina oaxacana, and Erythrina sousae have drug-like phytochemicals with potential anti-oxidant, anti-inflammatory, anti-aging, and anti-senescence effects. Between the drug-like phytochemicals, lonchocarpin, vallesine, and erysotrine exhibit potential anti-oxidant, anti-inflammatory, anti-aging, and anti-senescence effects. For the first time, we conducted an initial virtual screening of selected Mexican medicinal plants, which was subsequently confirmed in vivo, evaluating the anti-inflammatory activity of Lonchocarpus guatemalensis Benth in mice.

Marine heatwaves can limit the role of surfgrasses as biofilters for wastewaters.

Marine heatwaves (MHWs) can have detrimental effects on seagrasses, but knowledge about the impacts on their ecosystem services remains scarce. This work evaluated Phyllospadix scouleri (surgrass) as a biofilter for wastewater discharges, and how warming associated with MHW may affect this ecological function. The nitrogen uptake kinetics and assimilation abilities for ammonium, nitrate, and urea were examined under two different warming scenarios (single and repeated events) simulated in a mesocosm. N-uptake kinetics were related to urban sewage discharges close to surfgrass meadows. Our results revealed that surfgrasses can serve as effective biofilters because of their high nitrogen uptake rates and above-average canopy biomass. Nonetheless, exposure to both experimental warmings resulted in a significant decline in their ability to incorporate and assimilate nitrogen. Consequently, MHWs may reduce the capacity of surfgrasses to function as nitrogen sinks and green filters for sewage waters, jeopardizing their role as Blue Nitrogen systems.

Risk factors for graft loss and death among kidney transplant recipients: A competing risk analysis.

INTRODUCTION: Kidney transplantation is the best therapeutical option for CKD patients. Graft loss risk factors are usually estimated with the cox method. Competing risk analysis could be useful to determine the impact of different events affecting graft survival, the occurrence of an outcome of interest can be precluded by another. We aimed to determine the risk factors for graft loss in the presence of mortality as a competing event. METHODS: A retrospective cohort of 1454 kidney transplant recipients who were transplanted between July 1, 2008, to May 31, 2019, in Colombiana de Trasplantes, were analyzed to determine risk factors of graft loss and mortality at 5 years post-transplantation. Kidney and patient survival probabilities were estimated by the competing risk analysis. The Fine and Gray method was used to fit a multivariable model for each outcome. Three variable selection methods were compared, and the bootstrapping technique was used for internal validation as split method for resample. The performance of the final model was assessed calculating the prediction error, brier score, c-index and calibration plot. RESULTS: Graft loss occurred in 169 patients (11.6%) and death in 137 (9.4%). Cumulative incidence for graft loss and death was 15.8% and 13.8% respectively. In a multivariable analysis, we found that BKV nephropathy, serum creatinine and increased number of renal biopsies were significant risk factors for graft loss. On the other hand, recipient age, acute cellular rejection, CMV disease were risk factors for death, and recipients with living donor had better survival compared to deceased-donor transplant and coronary stent. The c-index were 0.6 and 0.72 for graft loss and death model respectively. CONCLUSION: We developed two prediction models for graft loss and death 5 years post-transplantation by a unique transplant program in Colombia. Using a competing risk multivariable analysis, we were able to identify 3 significant risk factors for graft loss and 5 significant risk factors for death. This contributes to have a better understanding of risk factors for graft loss in a Latin-American population. The predictive performance of the models was mild.

Spatial and temporal variations in water quality of Todos Santos Bay, northwestern Baja California, Mexico.

Coastal pollution levels in Todos Santos Bay (TSB) recreational beaches have increased in recent years due to the uncontrolled disposal of wastewater and pollutants to the coast by human activities (urbanization and tourism). In this work, the concentration of water quality parameters along the coast of TSB was evaluated from February 2012 to January 2013. Sampling was carried out at monthly intervals on 29 beach locations. Results showed that the maximum values of all parameters were always found close to the treated wastewater discharge area at Arroyo El Gallo station. Temporally, both nutrients and biochemical oxygen demand reached notably high levels in winter-spring and close to wastewater discharges. During summer, maximum counts of total coliforms and parasite eggs were detected close to wastewater discharges. Overall, our study provides a diagnostic approach on the spatiotemporal variability of water quality parameters for future studies along the coastal waters of TSB.

Substrate evaluation for biobeds in the degradation of ethylene bis-dithiocarbamate in wastewater from pesticide application in banana.

The efficacy of biobeds was evaluated by testing three agricultural residues (sugarcane top, banana stem, and eucalyptus chip) as substrates for the degradation of ethylene bis-dithiocarbamate (EBDC) and ethylene thiourea (ETU) in wastewater from banana spraying. Acrylic columns with a capacity to treat 1 L/ea. of wastewater were used as experimental units. Each unit was filled with different proportions of the test substrate (30%, 50% and 70% v/v) and the difference in volume was made up of equal parts of sugar cane cachasse and Fluvisol soil. Subsequently, the units were contaminated with suspensions of 878 mgL-1 of EBDC, and the dose was repeated periodically. The ETU concentration and leachate toxicity were evaluated every month for six months. The mixtures with 30% sugarcane top and 50% eucalyptus chip gave the best results, with leachable ETU concentrations down to a level protective of the environment, and toxicity down to background levels or nearly so. This was only found in mixtures with a high C:N ratio (20-25), thus, the effectiveness of the biobeds appears to be related to high lignolytic activity. .

Multispectral imaging detects gastritis consistently in mouse model and in humans.

Gastritis constitutes the initial step of the gastric carcinogenesis process. Gastritis diagnosis is based on histological examination of biopsies. Non-invasive real-time methods to detect mucosal inflammation are needed. Tissue optical properties modify reemitted light, i.e. the proportion of light that is emitted by a tissue after stimulation by a light flux. Analysis of light reemitted by gastric tissue could predict the inflammatory state. The aim of our study was to investigate a potential association between reemitted light and gastric tissue inflammation. We used two models and three multispectral analysis methods available on the marketplace. We used a mouse model of Helicobacter pylori infection and included patients undergoing gastric endoscopy. In mice, the reemitted light was measured using a spectrometer and a multispectral camera. We also exposed patient's gastric mucosa to specific wavelengths and analyzed reemitted light. In both mouse model and humans, modifications of reemitted light were observed around 560 nm, 600 nm and 640 nm, associated with the presence of gastritis lesions. These results pave the way for the development of improved endoscopes in order to detect real-time gastritis without the need of biopsies. This would allow a better prevention of gastric cancer alongside with cost efficient endoscopies.

Acute Rejection in Kidney Transplantation and Early Beginning of Tacrolimus.

BACKGROUND: Although tacrolimus is an effective immunosuppressive drug used for preventing biopsy proven acute rejection (BPAR) in kidney transplanted patients, its nephrotoxicity may compromise renal function and lead to delayed initiation because of its side effects. This study aimed to evaluate the safety of early initiation of tacrolimus in the occurrence of BPAR during the first 90 days post transplant. METHODS: We conducted a retrospective cohort study involving 315 patients who underwent kidney transplantation from 2015 to 2017. Comparisons were performed between 2 groups according to whether the start time of tacrolimus therapy was delayed or not delayed. Cox proportional hazards models were used to examine the association between variables and the occurrence of BPAR. RESULTS: The incidence of BPAR was 14.9% (n = 47) and it was significantly higher in the delayed group (19.4% vs 6.4%; P = .002). Delayed initiation tacrolimus group was significantly associated with the risk of BPAR (hazard ratio: 2.95; P < .036). The overall mortality rate was 2.5% (n = 8) and there was no association between delayed initiation therapy and death (P = .56). CONCLUSION: Our study confirmed that delayed initiation of tacrolimus in patients with delayed graft function is associated with a high risk of BPAR.

Departments involved during the first episode of acute heart failure and subsequent emergency department revisits and rehospitalisations: an outlook through the NOVICA cohort.

OBJECTIVES: We investigated the natural history of patients after a first episode of acute heart failure (FEAHF) requiring emergency department (ED) consultation, focusing on: the frequency of ED visits and hospitalisations, departments admitting patients during the first and subsequent hospitalisations, and factors associated with difficult disease control. METHODS AND RESULTS: We included consecutive patients diagnosed with FEAHF (either with or without previous heart failure diagnosis) in four EDs during 5 months in three different time periods (2009, 2011, 2014). Diagnosis was adjudicated by local principal investigators. The clinical characteristics of the index event were prospectively recorded, and all post-discharge ED visits and hospitalisations [related/unrelated to acute heart failure (AHF)], as well as departments involved in subsequent hospitalisations were retrospectively ascertained. 'Uncontrolled disease' during the first year after FEAHF was considered if patients were attended at ED (≥ 3 times) or hospitalised (≥ 2 times) for AHF or died. Overall, 505 patients with FEAHF were included and followed for a mean of 2.4 years. In-hospital mortality was 7.5%. Among 467 patients discharged alive, 288 died [median survival 3.9 years, 95% confidence interval (CI) 3.5-4.4], 421 (90%) revisited the ED (2342 ED visits; 42.4% requiring hospitalisation, 34.0% AHF-related) and 357 (77%) were hospitalised (1054 hospitalisations; 94.1% through ED, 51.4% AHF-related). AHF-related hospitalisations were mainly in internal medicine (28.0%), short-stay unit (26.3%), cardiology (20.8%), and geriatrics (14.1%). Only 47.4% of AHF-related hospitalisations were in the same department as the FEAHF, and internal medicine involvement significantly increased with subsequent hospitalisations (P = 0.01). Uncontrolled disease was observed in 31% of patients, which was independently related to age > 80 years [odds ratio (OR) 1.80, 95% CI 1.17-2.77], systolic blood pressure < 110 mmHg at ED arrival (OR 2.61, 95% CI 1.26-5.38) and anaemia (OR 2.39, 95% CI 1.51-3.78). CONCLUSION: In the present aged cohort of AHF patients from Barcelona, Spain, the natural history after FEAHF showed different patterns of hospital department involvement. Advanced age, low systolic blood pressure and anaemia were factors related to uncontrolled disease during the year after debut.

Impact of a pharmaceutical care programme for patients with chronic disease initiated at the emergency department on drug-related negative outcomes: a randomised controlled trial.

BACKGROUND: The resolution of potential drug-related problems is a priority of pharmaceutical care programmes. OBJECTIVES: To assess the clinical impact on drug-related negative outcomes of a pharmaceutical care programme focusing on the resolution of potential drug-related problems, initiated in the emergency department for patients with heart failure (HF) and/or chronic obstructive pulmonary disease (COPD). METHODS: Controlled trials, in which older adults (≥65 years) receiving four or more medications admitted to the emergency department for ≥12 hours for worsening of HF and/or COPD were randomised (1:1) to either a pharmaceutical care programme focusing on resolving potential drug-related problems initiated at the emergency department (intervention group (IG)) or standard care (control group). Comparisons between the groups were made for the proportion of patients with drug-related negative outcomes, number of drug-related negative outcomes per patient, mean stay, patients readmitted within 180 days and 180-day mortality. RESULTS: 118 patients were included, 59 in each group. Fewer patients in the IG had drug-related negative outcomes (37 (62.7%) vs 47 (79.7%) in the control group (p=0.042)). Fewer drug-related negative outcomes per patient occurred in the IG (56 (0.95 per patient) vs 85 (1.44 per patient) in the control group (p=0.01)). The mean stay was similar between groups (194.7 hours in the IG vs 242.5 hours in the control group (p=0.186)). No difference in revisits within 180 days was found (32 (54.24%) in the IG vs 22 (37.3%) in the control group (p=0.065)). 180-Day mortality was detected in 11 (18.6%) patients in the IG compared with 13 (22%) in the control group (p=0.647). CONCLUSION: A pharmaceutical care programme focusing on resolving potential drug-related problems initiated at the emergency department has a favourable clinical impact, as it reduces the number and prevalence of drug-related negative outcomes. No difference was found in other outcome variables.Trial registration number NCT02368548.

Evaluation of periodic breathing in respiratory flow signal of elderly patients using SVM and linear discriminant analysis.

Aging population is a major concern that is reflected in the increase of chronic diseases. Heart Failure (HF) is one of the most common chronic diseases of elderly people that is punctuated with acute episodes, which result in hospitalization. The periodic modulation of the amplitude of the breathing pattern is proved to be one of the multiple symptoms of an acute episode, and thus, the features extracted from its characterization contribute in the improvement of the first diagnosis of the clinical practice. The main objective of this study is to evaluate if the features extracted from the breathing pattern along with common clinical variables are reliable enough to detect Periodic Breathing (PB). A dataset of 44 elderly patients containing clinical information and a short record of electrocardiogram and respiratory flow signal was used to train two machine learning classification methods: Support Vector Machine (SVM) and Linear Discriminant Analysis (LDA). All the available clinical parameters within the dataset along with the parameters characterizing the respiratory pattern were used to classify the observations into two groups. SVM classification was optimized and performed using a = -8 and C = 10.04 giving an accuracy of 88.2 % sensitivity of 90 % and specificity of 85.7 % Similar results were achieved with LDA classifying with an accuracy of 82.4 %, a sensitivity of 81.8% and specificity of 83.3 % PB has been accurately detected using both classifiers.