Summary
Background
Rectal fluid administration may offer a simple, safe and inexpensive alternative to intravenous or nasogastric fluid therapy in equine clinical cases.
Objectives
To evaluate the ...tolerance and effects of rectally administered fluid and compare the measurements of haemodilution and intravascular volume with those during nasogastric and intravenous fluid administration.
Study design
Randomised controlled experimental trial.
Methods
Six clinically normal Standardbred geldings were used in a 4‐way crossover study: each received three different fluid treatments (intravenous, nasogastric and rectal) at 5 mL/kg/h for 6 h and underwent a control (no treatment) with water and feed withheld. Bodyweight was measured at baseline and 6 h. Packed cell volume (PCV), total solids (TS), albumin, electrolytes, lactate, urine specific gravity, vital parameters, gastrointestinal borborygmi and central venous pressure were measured every 2 h.
Results
Rectal fluid administration with plain water was well tolerated and caused clinical chemistry changes consistent with haemodilution, indicating absorption. Mean (95% confidence interval) PCV decreased from 40% 40–42 at 0 h to 35% 34–36 at 6 h during rectal fluid treatment (P<0.001), similar to decreases in PCV occurring also with i.v. and nasogastric (NGT) treatment (P<0.001). The TS also decreased with i.v. and rectal fluid (P<0.001). There was a decrease in bodyweight in the control (P<0.001) but not with any of the fluid treatments.
Main limitations
A small sample size of healthy, euhydrated horses and a relatively short duration of fluid administration was used.
Conclusions
Rectal fluid administration requires clinical evaluation, but may offer an inexpensive, safe alternative or adjunct to i.v. fluid administration, particularly when administration via NGT is not possible or contraindicated.
The Summary is available in Portuguese ‐ see Supporting Information
Progress of Pb‐Sn Mixed Perovskites for Photovoltaics: A Review Bandara, Rajapakshe Mudiyanselage Indrachapa; Silva, Shashini M.; Underwood, Cameron C. L. ...
Energy & environmental materials (Hoboken, N.J.),
April 2022, Letnik:
5, Številka:
2
Journal Article
Recenzirano
Odprti dostop
Pb‐Sn mixed perovskites are becoming increasingly popular as narrow‐bandgap (1.2–1.3 eV) light absorbers in single‐junction perovskite solar cells (PSCs) and as bottom cells for all‐perovskite tandem ...solar cells, for high‐efficiency, low‐cost, lightweight, roll‐to‐roll printable photovoltaic (PV) applications. From the first report of planar Pb:Sn mixed PSCs in 2014, the power conversion efficiencies (PCE) have increased from 10% to 21% by the end of 2020 with an exponential growth in research conducted in this field. Despite much effort, the performance and stability of Pb‐Sn mixed PSCs are still limited, which constrains their long‐term use in all‐perovskite tandem devices. This review highlights the avenues explored in improving different aspects of Pb‐Sn mixed PSCs and provides a comprehensive discussion of the interdependent factors affecting the device performance. This includes compositional engineering of the perovskite crystal, absorber layer fabrication and crystallization methods, bandgap tuning, Sn4+ reduction, and surface passivation of the absorber layer, as well as the selection of interlayers and electrodes of the final PSC.
This review on the progress of Pb‐Sn mixed perovskite solar cells discusses the recent developments in the field and highlights future directions for continuous improvements in device performances. It specially addresses the most recent efforts in Sn4+ reduction and surface passivation of the absorber layers, leading to high efficiencies of >21% for single‐junction Pb‐Sn mixed planar photovoltaic devices.
Background. Coronary revascularization with cardiopulmonary bypass has the potential risk of renal dysfunction related to the nonphysiologic nature of cardiopulmonary bypass. Recently, there has been ...a revival of interest in performing myocardial revascularization on the beating heart and we investigated whether this prevents renal compromise.
Methods. A prospective, randomized, controlled trial was performed in 50 patients (45 males, mean age 61 ± 3.7 years) undergoing elective coronary artery bypass grafting. Patients were randomly assigned to conventional revascularization with cardiopulmonary bypass (on pump) or beating heart revascularization (off pump). Glomerular and tubular function were assessed up to 48 hours postoperatively.
Results. There were no deaths, myocardial infarctions or acute renal failure in either group. Glomerular filtration as assessed by creatinine clearance and the urinary microalbumin/creatinine ratio was significantly worse in the on pump group (
p < 0.0004 and 0.0083, respectively). Renal tubular function was also impaired in the on pump group as assessed by increased N-acetyl glucosaminidase activity (
p < 0.0272).
Conclusions. These results suggest that off pump coronary revascularization offers a superior renal protection when compared with conventional coronary revascularization with cardiopulmonary bypass and cardioplegic arrest in first time coronary bypass patients.
We sought to investigate the effect of multiple coronary artery bypass grafting (CABG) with or without cardiopulmonary bypass (CPB) on the perioperative inflammatory response.
Sixty patients ...undergoing CABG were randomly assigned to one of two groups: (A) on pump with conventional CPB and cardioplegic arrest, and (B) off pump on the beating heart. Serum samples were collected for estimation of neutrophil elastase, interleukin 8 (IL-8), C3a, and C5a preoperatively and at 1, 4, 12, and 24 hours postoperatively. Furthermore, white blood cell (WBC), neutrophil, and monocyte counts were carried out preoperatively and at 1, 12, 36 and 60 hours postoperatively. Overall incidence of infection and perioperative clinical outcome were also recorded.
The groups were similar in terms of age, weight, gender ratio, extent of coronary disease, left ventricular function, and number of grafts per patient. Neutrophil elastase concentration peaked early after CPB in the on-pump group, with a decline with time. Repeated-measures analysis of variance between groups and comparisons at each time point (modified Bonferroni) showed elastase concentrations were significantly higher in the on-pump than the off-pump group (both p < 0.0001). IL-8 increased significantly after surgery in the on-pump group, with no decline during the observation period (p = 0.01 vs off pump). C3a and C5a rose early after surgery in both groups when compared with baseline values. Postoperative WBC, neutrophil, and monocyte counts were significantly higher in the on-pump than the off-pump group (p < 0.01). Finally, the incidence of postoperative overall infections was significantly higher in the on-pump group (p < 0.0001 vs off pump).
CABG on the beating heart is associated with a significant reduction in inflammatory response and postoperative infection when compared with conventional revascularization with CPB and cardioplegic arrest.
The molecular mechanisms responsible for postpollination changes in floral scent emission were investigated in snapdragon cv Maryland True Pink and petunia cv Mitchell flowers using a volatile ester, ...methylbenzoate, one of the major scent compounds emitted by these flowers, as an example. In both species, a 70 to 75% pollination-induced decrease in methylbenzoate emission begins only after pollen tubes reach the ovary, a process that takes between 35 and 40 h in snapdragon and ∼32 h in petunia. This postpollination decrease in emission is not triggered by pollen deposition on the stigma. Petunia and snapdragon both synthesize methylbenzoate from benzoic acid and S-adenosyl-L-methionine (SAM); however, they use different mechanisms to downregulate its production after pollination. In petunia, expression of the gene responsible for methylbenzoate synthesis is suppressed by ethylene. In snapdragon, the decrease in methylbenzoate emission is the result of a decrease in both S-adenosyl-L-methionine:benzoic acid carboxyl methyltransferase (BAMT) activity and the ratio of SAM to S-adenosyl-L-homocysteine ("methylation index") after pollination, although the BAMT gene also is sensitive to ethylene.
Atrial fibrillation (AF) increases the morbidity of CABG. The pathophysiology is uncertain, and its prevention remains suboptimal. This prospective, randomized study was designed to define the role ...of cardiopulmonary bypass (CPB) and cardioplegic arrest in the pathogenesis of this complication.
Two hundred patients were prospectively randomized to (1) on-pump conventional surgery (100 patients, 79 men, mean age 63 (40 to 77) years) with normothermic CPB and cardioplegic arrest of the heart or (2) off-pump surgery (100 patients, 82 men, mean age 63 (38 to 86) years) on the beating heart. Heart rate and rhythm were continuously monitored with an automated arrhythmia detector during the first 72 hours after surgery. Thereafter, routine clinical observation was performed and continuous monitoring restarted in the case of arrhythmia. The association of perioperative factors with AF was investigated by univariate analysis. Significant variables were then included into a stepwise logistic regression model to ascertain their independent influence on the occurrence of AF. There were no significant baseline differences between groups. Thirty-nine patients in the on-pump group and 8 patients in the off-pump group had postoperative sustained AF (P:=0.001). Univariate analysis showed that CPB inclusive of cardioplegic arrest, postoperative inotropic support, intubation time, chest infection, and hospital length of stay were predictors of AF (all P:<0.05). However, stepwise multivariate regression analysis identified CPB inclusive of cardioplegic arrest as the only independent predictor of postoperative AF (OR 7.4; CI 3.4 to 17.9).
CPB inclusive of cardioplegic arrest is the main independent predictor of postoperative AF in patients undergoing coronary revascularization.
We measured the nuclear-recoil ionization yield in silicon with a cryogenic phonon-sensitive gram-scale detector. Neutrons from a mono-energetic beam scatter off of the silicon nuclei at angles ...corresponding to energy depositions from 4 keV down to 100 eV, the lowest energy probed so far. The results show no sign of an ionization production threshold above 100 eV. In conclusion, these results call for further investigation of the ionization yield theory and a comprehensive determination of the detector response function at energies below the keV scale.
The CDMS low ionization threshold experiment (CDMSlite) uses cryogenic germanium detectors operated at a relatively high bias voltage to amplify the phonon signal in the search for weakly interacting ...massive particles (WIMPs). Results are presented from the second CDMSlite run with an exposure of 70 kg day, which reached an energy threshold for electron recoils as low as 56 eV. A fiducialization cut reduces backgrounds below those previously reported by CDMSlite. New parameter space for the WIMP-nucleon spin-independent cross section is excluded for WIMP masses between 1.6 and 5.5 GeV/c^{2}.
Objectives This study sought to compare catheter ablation with rate control for persistent atrial fibrillation (AF) in heart failure (HF). Background The optimal therapy for AF in HF is unclear. ...Drug-based rhythm control has not proved clinically beneficial. Catheter ablation improves cardiac function in patients with HF, but impact on physiological performance has not been formally evaluated in a randomized trial. Methods In a randomized, open-label, blinded-endpoint clinical trial, adults with symptomatic HF, radionuclide left ventricular ejection fraction (EF) ≤35%, and persistent AF were assigned to undergo catheter ablation or rate control. Primary outcome was 12-month change in peak oxygen consumption. Secondary endpoints were quality of life, B-type natriuretic peptide, 6-min walk distance, and EF. Results were analyzed by intention-to-treat. Results Fifty-two patients (age 63 ± 9 years, EF 24 ± 8%) were randomized, 26 each to ablation and rate control. At 12 months, 88% of ablation patients maintained sinus rhythm (single-procedure success 68%). Under rate control, rate criteria were achieved in 96%. The primary endpoint, peak oxygen consumption, significantly increased in the ablation arm compared with rate control (difference +3.07 ml/kg/min, 95% confidence interval: 0.56 to 5.59, p = 0.018). The change was not evident at 3 months (+0.79 ml/kg/min, 95% confidence interval: −1.01 to 2.60, p = 0.38). Ablation improved Minnesota score (p = 0.019) and B-type natriuretic peptide (p = 0.045) and showed nonsignificant trends toward improved 6-min walk distance (p = 0.095) and EF (p = 0.055). Conclusions This first randomized trial of ablation versus rate control to focus on objective exercise performance in AF and HF shows significant benefit from ablation, a strategy that also improves symptoms and neurohormonal status. The effects develop over 12 months, consistent with progressive amelioration of the HF syndrome. (A Randomised Trial to Assess Catheter Ablation Versus Rate Control in the Management of Persistent Atrial Fibrillation in Chronic Heart Failure; NCT00878384 )
SuperCDMS SNOLAB will be a next-generation experiment aimed at directly detecting low-mass particles (with masses ≤10 GeV/c2) that may constitute dark matter by using cryogenic detectors of two types ...(HV and iZIP) and two target materials (germanium and silicon). The experiment is being designed with an initial sensitivity to nuclear recoil cross sections ∼1×10−43 cm2 for a dark matter particle mass of 1 GeV/c2, and with capacity to continue exploration to both smaller masses and better sensitivities. The phonon sensitivity of the HV detectors will be sufficient to detect nuclear recoils from sub-GeV dark matter. A detailed calibration of the detector response to low-energy recoils will be needed to optimize running conditions of the HV detectors and to interpret their data for dark matter searches. Low-activity shielding, and the depth of SNOLAB, will reduce most backgrounds, but cosmogenically produced H3 and naturally occurring Si32 will be present in the detectors at some level. Even if these backgrounds are 10 times higher than expected, the science reach of the HV detectors would be over 3 orders of magnitude beyond current results for a dark matter mass of 1 GeV/c2. The iZIP detectors are relatively insensitive to variations in detector response and backgrounds, and will provide better sensitivity for dark matter particles with masses ≳5 GeV/c2. The mix of detector types (HV and iZIP), and targets (germanium and silicon), planned for the experiment, as well as flexibility in how the detectors are operated, will allow us to maximize the low-mass reach, and understand the backgrounds that the experiment will encounter. Upgrades to the experiment, perhaps with a variety of ultra-low-background cryogenic detectors, will extend dark matter sensitivity down to the “neutrino floor,” where coherent scatters of solar neutrinos become a limiting background.
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