Category: Nevin Manimala

Small. 2021 Mar 29:e2100040. doi: 10.1002/smll.202100040. Online ahead of print.

ABSTRACT

Ni-rich cathode materials provide high energy density, but their structural and surface instability limits their cyclability and thermal stability. As one of the approaches to mitigate this problem, cathode materials comprising Ni-rich high-capacity core wrapped in Mn-rich multiple shells are produced successfully. In contrast to the conventional batch-type process for concentration-gradient materials, a digital-gradient cascade coprecipitation process described here achieves the improvements in productivity and quality consistency needed to move toward large-scale manufacturing. The core-multishell cathode materials produced in this manner not only have longer cycle life and improved rate performance compared to homogeneous Ni-rich cathode materials having the same overall composition, but also show remarkably enhanced thermal stability and low impedance growth characteristics. In a novel attempt to determine the correlation between the mechanical properties of the core-multishell cathode particles and their electrochemical cyclabilities, their breaking force and elasticity were successfully measured using a statistical approach, which indicates that a cathode particle with stable surface composition as well as high breaking force has improved capacity retention and durability. These results guide the realization of long life and high thermal stability in Ni-rich cathode materials through heterogeneous particle engineering.

PMID:33783108 | DOI:10.1002/smll.202100040

Biol Rev Camb Philos Soc. 2021 Mar 29. doi: 10.1111/brv.12712. Online ahead of print.

ABSTRACT

Physical exercise not only helps to improve physical health but can also enhance brain development and cognition. Recent reports on parental (both maternal and paternal) effects raise the possibility that parental exercise may provide benefits to offspring through intergenerational inheritance. However, the general magnitude and consistency of parental exercise effects on offspring is still controversial. Additionally, empirical research has long overlooked an important aspect of exercise: its effects on variability in neurodevelopmental and cognitive traits. Here, we compiled data from 52 studies involving 4786 rodents (412 effect sizes) to quantify the intergenerational transmission of exercise effects on brain and cognition. Using a multilevel meta-analytic approach, we found that, overall, parental exercise showed a tendency for increasing their offspring’s brain structure by 12.7% (albeit statistically non-significant) probably via significantly facilitating neurogenesis (16.5%). Such changes in neural anatomy go in hand with a significant 20.8% improvement in neurobehaviour (improved learning and memory, and reduced anxiety). Moreover, we found parental exercise significantly reduces inter-individual differences (i.e. reduced variance in the treatment group) in progeny’s neurobehaviour by 10.2% (coefficient of variation ratio, lnCVR), suggesting the existence of an individual by intervention interaction. The positive effects of exercise are modulated by several covariates (i.e. moderators), such as the exercised parent’s sex, offspring’s sex, and age, mode of exercise, and exercise timing. In particular, parental forced exercise is more efficient than voluntary exercise at significantly improving offspring neurobehaviour (26.0%) and reducing its variability (14.2%). We observed larger effects when parental exercise started before pregnancy. However, exercising only during pregnancy also had positive effects. Mechanistically, exercise significantly upregulated brain-derived neurotrophic factor (BDNF) by 28.9%, vascular endothelial growth factor (VEGF) by 35.8%, and significantly decreased hippocampal DNA methylation by 3.5%, suggesting that brain growth factor cascades and epigenetic modifications can moderate the transmission of parental exercise effects. Collectively, by coupling mean with variance effects, our analyses draw a more integrated picture of the benefits that parental exercise has on offspring: not only does it improve offspring brain development and cognitive performance, but it also reduces inter-individual differences in cognition-related traits. We advocate that meta-analysis of variation together with the mean of a trait provides novel insights for old controversies as well as emerging new questions, opening up a new era for generating variance-based hypotheses.

PMID:33783115 | DOI:10.1111/brv.12712

J Magn Reson Imaging. 2021 Mar 29. doi: 10.1002/jmri.27611. Online ahead of print.

ABSTRACT

BACKGROUND: Chemical shift encoded magnetic resonance imaging (CSE-MRI)-based tissue fat quantification is confounded by increased R2* signal decay rate caused by the presence of excess iron deposition.

PURPOSE: To determine the upper limit of R2* above which it is no longer feasible to quantify proton density fat fraction (PDFF) reliably, using CSE-MRI.

STUDY TYPE: Prospective.

POPULATION: Cramér-Rao lower bound (CRLB) calculations, Monte Carlo simulations, phantom experiments, and a prospective study in 26 patients with known or suspected liver iron overload.

FIELD STRENGTH/SEQUENCE: Multiecho gradient echo at 1.5 T and 3.0 T.

ASSESSMENT: CRLB calculations were used to develop an empirical relationship between the maximum R2* value above which PDFF estimation will achieve a desired number of effective signal averages. A single voxel multi-TR, multi-TE stimulated echo acquisition mode magnetic resonance spectroscopy acquisition was used as a reference standard to estimate PDFF. Reconstructed PDFF and R2* maps were analyzed by one analyst using multiple regions of interest drawn in all nine Couinaud segments.

STATISTICAL TESTS: None.

RESULTS: Simulations, phantom experiments, and in vivo measurements demonstrated unreliable PDFF estimates with increased R2*, with PDFF errors as large as 20% at an R2* of 1000 s^-1 . For typical optimized Cartesian acquisitions (TE1 = 0.75 msec, ΔTE = 0.67 msec at 1.5 T, TE1 = 0.65 msec, ΔTE = 0.58 msec at 3.0 T), an empirical relationship between PDFF estimation errors and acquisition parameters was developed that suggests PDFF estimates are unreliable above an R2* of ~538 s^-1 and ~779 s^-1 at 1.5 T and 3 T, respectively. This empirical relationship was further investigated with phantom experiments and in vivo measurements, with PDFF errors at an R2* of 1000 s^-1 at 3.0 T as large as 10% with TE1 = 1.24 msec, ΔTE = 1.01 msec compared to 3% with TE1 = 0.65 msec, ΔTE = 0.58 msec.

DATA CONCLUSION: We successfully developed a theoretically-based empirical formula that may provide an easily calculable guideline to identify R2* values above which PDFF is not reliable in research and clinical applications using CSE-MRI to quantify PDFF in the presence of iron overload.

LEVEL OF EVIDENCE: 1 TECHNICAL EFFICACY STAGE: 1.

PMID:33783066 | DOI:10.1002/jmri.27611

Stat Med. 2021 Mar 29. doi: 10.1002/sim.8949. Online ahead of print.

ABSTRACT

We design two-stage confirmatory clinical trials that use adaptation to find the subgroup of patients who will benefit from a new treatment, testing for a treatment effect in each of two disjoint subgroups. Our proposal allows aspects of the trial, such as recruitment probabilities of each group, to be altered at an interim analysis. We use the conditional error rate approach to implement these adaptations with protection of overall error rates. Applying a Bayesian decision-theoretic framework, we optimize design parameters by maximizing a utility function that takes the population prevalence of the subgroups into account. We show results for traditional trials with familywise error rate control (using a closed testing procedure) as well as for umbrella trials in which only the per-comparison type 1 error rate is controlled. We present numerical examples to illustrate the optimization process and the effectiveness of the proposed designs.

PMID:33783020 | DOI:10.1002/sim.8949

Clin Exp Pharmacol Physiol. 2021 Mar 30. doi: 10.1111/1440-1681.13501. Online ahead of print.

ABSTRACT

Colorectal surgery is associated with an above-average mortality rate of ~15%. During surgery, maintenance of vital organ perfusion is essential in order to reduce postoperative mortality and morbidity, with renal perfusion of particular importance. Oesophageal Doppler monitors (ODM) are commonly used to try and provide accurate measures of fluid depletion during surgery, however it is unclear to what extent they reflect organ perfusion. In addition, it is not known whether macro- and/ or microvascular perfusion indices are associated with renal complications following colorectal surgery. Thirty-two participants scheduled for colorectal surgery had three measures of macro- and microvascular renal blood flow via contrast enhanced ultrasound (CEUS), and simultaneous measures of cardiac output indicies via ODM: i) pre-operatively; ii) intra-operatively at the mid-point of operation, and iii) after the conclusion of surgery. The Postoperative Morbidity Survey (POMS) was used to assess postoperative complications. Intra-operatively, there was a significant correlation between renal microvascular flow (RT) and renal macrovascular flow (TTI) (rho=0.52; p=0.003). Intra-operative TTI, but not RT, was associated with cardiac index (rho= -0.50; p=0.0003). Intra-operative RT predicted increases in renal complications (OR 1.46; 95% CI 1.03 to 2.09) with good discrimination (C-statistic, 0.85). Complications were not predicted by TTI or ODM-derived indices. There was no relationship between RT and TTI before or after surgery. ODM measures of haemodynamic status do not correlate with renal microvascular blood flow, and as such are likely not suitable to determine vital organ perfusion. Only CEUS-derived measures of microvascular perfusion were predictive of postoperative renal complications.

PMID:33783024 | DOI:10.1111/1440-1681.13501

Clin Transplant. 2021 Mar 30:e14301. doi: 10.1111/ctr.14301. Online ahead of print.

ABSTRACT

BACKGROUND: The coupling of increased life expectancy and improvements in both quality and access to chronic liver disease care, is culminating in an expanding population of septuagenarians (≥ 70 years) in need of liver transplantation (LT). The objective of this study is to partially alleviate this knowledge deficit and to add clarity to the current status and role of LDLT in this recipient population.

METHODS: 295 adult patients underwent LDLT between January 1, 2011 and December 31, 2016. Twelve (4%) of these patients were septuagenarians and this group was compared to younger cohort (n=283) .

RESULTS: Comorbidity profiles between the two groups were similar and no statistically significant differences were noted in warm/cold ischemia times, operative duration, or blood product utilization. ICU and total hospital stays were comparable. Septuagenarian 1-and 5-year graft and patient survivals were identical at 91.7%. Their younger counterparts had 1-and 5-year patient survivals of 91.1% and 84.0 % accompanied by 1-and 5-year graft survivals of 89.8% and 82.7%, respectively.

CONCLUSION: our study highlights a recognition that LDLT can afford highly-selected elderly patients to access to transplant with equivalent outcomes to those realized by younger recipients.

PMID:33783041 | DOI:10.1111/ctr.14301

Nurs Forum. 2021 Mar 29. doi: 10.1111/nuf.12573. Online ahead of print.

ABSTRACT

BACKGROUND: Modern innovative education approaches are crucial for nursing education, which leads to improving evidence-based teaching strategies and preparing nursing students for their future workplaces. The primary aim of the study was a comparison of the effectiveness of the flipped classroom and traditional educational methods on the attainment of knowledge regarding venous thromboembolism (VTE) prevention among nursing students. In addition, investigation of the opinions of the nursing students regarding the advantages and disadvantages flipped classroom educational method was the secondary aim of the study.

METHODS: This study was implemented with a randomized controlled design in the Faculty of Nursing in September and October 2019, with 118 first- and second-semester undergraduate nursing students (58 students in the flipped classroom, 60 students in the traditional lecture) who had not taken the Adult Health Nursing course. Implementation of the study was conducted in three phases: pretest, educational intervention, and posttest for both groups.

RESULTS: The study findings demonstrated no statistically significant difference in any of the mean scores of VTE domains between the two groups in the pretest. However, the flipped classroom group had higher mean scores of all VTE domains compared with the traditional lecture group in the posttest. Mostly, students highlighted four advantages of the flipped classroom, including “Deep motive,” “Engagement,” “Cost-effectiveness,” and “Self-confidence.”

CONCLUSIONS: The flipped classroom method proved to have positive effects in VTE domains in terms of knowledge, risk assessment, and prophylaxis among nursing students. This method can be recommended as an innovative and student-centered method in the teaching of evidence-based nursing practices.

PMID:33782992 | DOI:10.1111/nuf.12573

Psychophysiology. 2021 Mar 29:e13793. doi: 10.1111/psyp.13793. Online ahead of print.

ABSTRACT

Event-related potentials (ERPs) can be very noisy, and yet, there is no widely accepted metric of ERP data quality. Here, we propose a universal measure of data quality for ERP research-the standardized measurement error (SME)-which is a special case of the standard error of measurement. Whereas some existing metrics provide a generic quantification of the noise level, the SME quantifies the data quality (precision) for the specific amplitude or latency value being measured in a given study (e.g., the peak latency of the P3 wave). It can be applied to virtually any value that is derived from averaged ERP waveforms, making it a universal measure of data quality. In addition, the SME quantifies the data quality for each individual participant, making it possible to identify participants with low-quality data and “bad” channels. When appropriately aggregated across individuals, SME values can be used to quantify the combined impact of the single-trial EEG noise and the number of trials being averaged together on the effect size and statistical power in a given experiment. If SME values were regularly included in published articles, researchers could identify the recording and analysis procedures that produce the highest data quality, which could ultimately lead to increased effect sizes and greater replicability across the field.

PMID:33782996 | DOI:10.1111/psyp.13793

Stat Med. 2021 Mar 29. doi: 10.1002/sim.8962. Online ahead of print.

ABSTRACT

Interval-censored failure time data commonly arise in epidemiological and biomedical studies where the occurrence of an event or a disease is determined via periodic examinations. Subject to interval-censoring, available information on the failure time can be quite limited. Cost-effective sampling designs are desirable to enhance the study power, especially when the disease rate is low and the covariates are expensive to obtain. In this work, we formulate the case-cohort design with multiple interval-censored disease outcomes and also generalize it to nonrare diseases where only a portion of diseased subjects are sampled. We develop a marginal sieve weighted likelihood approach, which assumes that the failure times marginally follow the proportional hazards model. We consider two types of weights to account for the sampling bias, and adopt a sieve method with Bernstein polynomials to handle the unknown baseline functions. We employ a weighted bootstrap procedure to obtain a variance estimate that is robust to the dependence structure between failure times. The proposed method is examined via simulation studies and illustrated with a dataset on incident diabetes and hypertension from the Atherosclerosis Risk in Communities study.

PMID:33783001 | DOI:10.1002/sim.8962

J Card Surg. 2021 Mar 30. doi: 10.1111/jocs.15516. Online ahead of print.

ABSTRACT

OBJECTIVES: Some patients who undergo transcatheter aortic valve replacement (TAVR) have a concomitant diverse aortic pathologies (AP). They are usually considered high-risk candidates for the procedure and require further assessment to determine the best vascular approach. The impact of these AP on TAVR is not well known as the information is scarce. We aimed to evaluate midterm clinical impact of different AP after transapical (TA)-TAVR.

METHODS: Twenty patients with atherosclerotic/occluding aortic diseases (A/OAD) (porcelain aorta, Leriche Syndrome, penetrating aortic ulcer, and aortic thrombus), 24 patients with aortic morphologic diseases (AMD) (thoracic/abdominal aortic aneurysms, aortic kinking, aortic type B dissection, aortic elongation/tortuosity, and previous aortic intervention), and 11 patients with combined aortic diseases (CAD) underwent TA-TAVR treatment between January 2011 and November 2019 at our center. We conducted up to 5-years clinical follow-up.

RESULTS: All patients were classified in the heart team as a high interventional risk. The 30-day mortality and stroke were 5% and 10% in the A/OAD, 8.3% and 0% in the AMD, and 0% and 0% in the CAD, respectively. The median time of freedom from a composite of death and cardio-cerebral adverse events was 22.1 months [95% confidence interval [CI]: 9.9-34.3] in A/OAD versus 34.3 months [95% CI: 15.6-53] in AMD versus 17 months [95% CI: 0-39.4] in CAD; p = .525. We registered neither procedural aortic injury nor aortic syndrome at follow-up. The moderate/severe paravalvular leakage rates were 5%, 0% and 0% in the A/OAD, AMD and CAD, respectively.

CONCLUSION: Independent of underlying AP, the TA-TAVR is a safe method and shows very promising early and midterm outcomes in patients with various AP.

PMID:33783007 | DOI:10.1111/jocs.15516