To understand the complex physics of a system with strong electron-electron interactions, the ideal is to control and monitor its properties while tuning an external electric field applied to the ...system (the electric-field effect). Indeed, complete electric-field control of many-body states in strongly correlated electron systems is fundamental to the next generation of condensed matter research and devices. However, the material must be thin enough to avoid shielding of the electric field in the bulk material. Two-dimensional materials do not experience electrical screening, and their charge-carrier density can be controlled by gating. Octahedral titanium diselenide (1T-TiSe2) is a prototypical two-dimensional material that reveals a charge-density wave (CDW) and superconductivity in its phase diagram, presenting several similarities with other layered systems such as copper oxides, iron pnictides, and crystals of rare-earth elements and actinide atoms. By studying 1T-TiSe2 single crystals with thicknesses of 10 nanometres or less, encapsulated in two-dimensional layers of hexagonal boron nitride, we achieve unprecedented control over the CDW transition temperature (tuned from 170 kelvin to 40 kelvin), and over the superconductivity transition temperature (tuned from a quantum critical point at 0 kelvin up to 3 kelvin). Electrically driving TiSe2 over different ordered electronic phases allows us to study the details of the phase transitions between many-body states. Observations of periodic oscillations of magnetoresistance induced by the Little-Parks effect show that the appearance of superconductivity is directly correlated with the spatial texturing of the amplitude and phase of the superconductivity order parameter, corresponding to a two-dimensional matrix of superconductivity. We infer that this superconductivity matrix is supported by a matrix of incommensurate CDW states embedded in the commensurate CDW states. Our results show that spatially modulated electronic states are fundamental to the appearance of two-dimensional superconductivity.
Diffuse leukoencephalopathy and juxtacortical and/or callosal microhemorrhages were brain imaging features in critically ill patients with coronavirus disease 2019. Coronavirus disease 2019 ...(COVID-19) has been reported in association with a variety of brain imaging findings such as ischemic infarct, hemorrhage, and acute hemorrhagic necrotizing encephalopathy. Herein, the authors report brain imaging features in 11 critically ill patients with COVID-19 with persistently diminished mental status who underwent MRI between April 5 and April 25, 2020. These imaging features include
confluent T2 hyperintensity and mild restricted diffusion in bilateral supratentorial deep and subcortical white matter (in 10 of 11 patients) and
multiple punctate microhemorrhages in juxtacortical and callosal white matter (in seven of 11 patients). The authors also discuss potential pathogeneses.
This paper investigates on power-sharing issues of an autonomous hybrid microgrid. Unlike existing microgrids which are purely ac, the hybrid microgrid studied here comprises dc and ac subgrids ...interconnected by power electronic interfaces. The main challenge here is to manage power flows among all sources distributed throughout the two types of subgrids, which is certainly tougher than previous efforts developed for only ac or dc microgrid. This wider scope of control has not yet been investigated, and would certainly rely on the coordinated operation of dc sources, ac sources, and interlinking converters. Suitable control and normalization schemes are now developed for controlling them with the overall hybrid microgrid performance already verified in simulation and experiment.
Abstract
Emerging reports raise concerns on the potential association between the COVID-19 vaccines and cardiac manifestations. We sought to evaluate cardiac complications associated with COVID-19 ...vaccination in a pooled analysis from our institution’s cohort study and systematic review. Consecutive patients admitted to a tertiary hospital in Singapore between 1 January 2021 and 31 March 2021, with the onset of cardiac manifestations within 14 days following COVID-19 vaccination, were studied. Furthermore, a systematic review was performed, with PubMed, Embase, Research Square, MedRxiv and LitCovid databases accessed from inception up to 29 June 2021. Relevant manuscripts reporting individual patient data on cardiac complications following COVID-19 vaccination were included. Thirty patients were included in the study cohort, with 29 diagnosed with acute myocardial infarction (AMI) and 1 with myocarditis. Five patients developed heart failure, two had cardiogenic shock, three intubated, and one had cardiovascular-related mortality. In the systematic review, 16 studies were included with 41 myocarditis and 6 AMI cases. In the pooled analysis of the study cohort and the systematic review, 35 patients had AMI and 42 had myocarditis. Majority were men, and myocarditis patients were younger than AMI patients. Myocarditis patients tended to present 72 h postvaccination, while AMI patients were older and typically presented 24 h postvaccination. Majority with AMI or myocarditis developed symptoms after the first and second vaccination dose, respectively. This pooled analysis of patients presenting with cardiac manifestations following COVID-19 vaccination highlights the differences between myocarditis and AMI presentations in temporal association with the vaccination.
Studies suggest that dysfunction of brain-derived neurotrophic factor (BDNF) is a possible contributor to the pathology and symptoms of Alzheimer's disease (AD). Several studies report reduced ...peripheral blood levels of BDNF in AD, but findings are inconsistent. This study sought to quantitatively summarize the clinical BDNF data in patients with AD and mild cognitive impairment (MCI, a prodromal stage of AD) with a meta-analytical technique. A systematic search of Pubmed, PsycINFO and the Cochrane Library identified 29 articles for inclusion in the meta-analysis. Random-effects meta-analysis showed that patients with AD had significantly decreased baseline peripheral blood levels of BDNF compared with healthy control (HC) subjects (24 studies, Hedges' g=-0.339, 95% confidence interval (CI)=-0.572 to -0.106, P=0.004). MCI subjects showed a trend for decreased BDNF levels compared with HC subjects (14 studies, Hedges' g=-0.201, 95% CI=-0.413 to 0.010, P=0.062). No differences were found between AD and MCI subjects in BDNF levels (11 studies, Hedges' g=0.058, 95% CI=-0.120 to 0.236, P=0.522). Interestingly, the effective sizes and statistical significance improved after excluding studies with reported medication in patients (between AD and HC: 18 studies, Hedges' g=-0.492, P<0.001; between MCI and HC: 11 studies, Hedges' g=-0.339, P=0.003). These results strengthen the clinical evidence that AD or MCI is accompanied by reduced peripheral blood BDNF levels, supporting an association between the decreasing levels of BDNF and the progression of AD.
Most methods for assessing microvascular function are not readily available in the cardiac catheterization laboratory. The aim of this study is to determine whether the Index of Microcirculatory ...Resistance (IMR), measured at the time of primary percutaneous coronary intervention, is predictive of death and rehospitalization for heart failure.
IMR was measured immediately after primary percutaneous coronary intervention in 253 patients from 3 institutions with the use of a pressure-temperature sensor wire. The primary end point was the rate of death or rehospitalization for heart failure. The prognostic value of IMR was compared with coronary flow reserve, TIMI myocardial perfusion grade, and clinical variables. The mean IMR was 40.3±32.5. Patients with an IMR >40 had a higher rate of the primary end point at 1 year than patients with an IMR ≤40 (17.1% versus 6.6%; P=0.027). During a median follow-up period of 2.8 years, 13.8% experienced the primary end point and 4.3% died. An IMR >40 was associated with an increased risk of death or rehospitalization for heart failure (hazard ratio HR, 2.1; P=0.034) and of death alone (HR, 3.95; P=0.028). On multivariable analysis, independent predictors of death or rehospitalization for heart failure included IMR >40 (HR, 2.2; P=0.026), fractional flow reserve ≤0.8 (HR, 3.24; P=0.008), and diabetes mellitus (HR, 4.4; P<0.001). An IMR >40 was the only independent predictor of death alone (HR, 4.3; P=0.02).
An elevated IMR at the time of primary percutaneous coronary intervention predicts poor long-term outcomes.
This study compares the environmental impacts of a polycrystalline photovoltaic (PV) module and a wind turbine using the life cycle assessment (LCA) method. This study models landfill disposal and ...recycling scenarios of the decommissioned PV module and wind turbine, and compares their impacts to those of the other stages in the life cycles. The comparison establishes that the wind turbine has smaller environmental impacts in almost all of the categories assessed. The disposal stage can become a major contributor to the environmental impacts, depending on disposal scenarios. Recycling is an environmentally efficient method, because of its environmental benefits derived from energy savings and resource reclaimed. The end-of-life recycling scenario for a wind turbine has a significant part on the environmental impacts and should not be ignored. However, many factors also influence the degree to which recycling can be beneficial. With the wind turbine recycling scenario, when large quantities of waste are recycled, the potential savings can be quite large, while with the PV module, small quantities of recycled waste mean that the benefits of recycling are not fully reaped.
► The wind turbine has smaller impacts in almost all the categories assessed than the PV module. ► The disposal stage can be a major contributor to environmental impacts. ► End-of-life recycling scenarios for a wind turbine have significant roles. ► For the wind turbine with large quantities of waste recycled, potential savings are large. ► For the PV module with small quantities of waste recycled, benefits are not fully reaped.
Preoperative carbohydrate loading in Enhanced Recovery After Surgery is an independent predictor of postoperative outcomes. By reducing the impact of surgical stress response, fasting-induced insulin ...resistance is modulated. As a clear fluid, consuming carbohydrate drink is safe up to 2 h preoperatively. Widely practiced in abdominal surgeries, its implementation in hip fracture surgeries is yet to be recognized. This study aimed to identify the feasibility of preoperative carbohydrate loading in hip fracture surgery and assess its clinical effects.
This was a randomized controlled, open labelled trial. Patients ≥ 65 years old without diabetes mellitus, has hip fracture were recruited in a tertiary hospital between November 2020 and May 2021. The intervention was carbohydrate loading versus standard preoperative fasting.
Thirty-four ASA I-III patients (carbohydrate loading and control, n = 17 each), mean age 78 years (SEM ± 1.5), mean body mass index 23.7 (SEM ± 0.6 kg/m
) were recruited. Analysis for feasibility of carbohydrate loading (n = 17) demonstrated attrition rate of 29% (n = 5). Otherwise, all recruited patients were compliant (100% compliance) with no adverse events reported. There was no significant difference among groups in the postoperative nausea and vomiting, pain score, fatigue level, muscle strength, postoperative infection and length of hospital stay assessed at 24-48 h postoperatively.
The implementation of preoperative carbohydrate loading was found to be feasible preoperatively in hip fracture surgeries but requires careful coordination among multidisciplinary teams. An adequately powered randomized controlled study is needed to examine the full benefits of preoperative carbohydrate loading in this group of patients.
This study was registered in ClinicalTrial.gov (ClinicalTrials.gov identifier: NCT04614181, date of registration: 03/11/2020).
Background Deletion of 1p is associated with poor prognosis in neuroblastoma, however selected 1p-intact patients still experience poor outcomes. Since mutations of 1p genes may mimic the deleterious ...effects of chromosomal loss, we studied the incidence, spectrum and effects of mutational variants in 1p-intact neuroblastoma. Methods We characterized the 1p status of 325 neuroblastoma patients, and correlated the mutational status of 1p tumor suppressors and neuroblastoma candidate genes with survival outcomes among 100 1p-intact cases, then performed functional validation of selected novel variants of 1p36 genes identified from our patient cohort. Results Among patients with adverse disease characteristics, those who additionally had 1p deletion had significantly worse overall survival. Among 100 tumor-normal pairs sequenced, somatic mutations of 1p tumor suppressors KIF1Bbeta and CHD5 were most frequent (2%) after ALK and ATRX (8%), and BARD1 (3%). Mutations of neuroblastoma candidate genes were associated with other synchronous mutations and concurrent 11q deletion (P = 0.045). In total, 24 of 38 variants identified were novel and predicted to be deleterious or pathogenic. Functional validation identified novel KIF1Bbeta I1355M variant as a gain-of-function mutation with increased expression and tumor suppressive activity, correlating with indolent clinical behavior; another novel variant CHD5 E43Q was a loss-of-function mutation with decreased expression and increased long-term cell viability, corresponding with aggressive disease characteristics. Conclusions Our study showed that chromosome 1 gene mutations occurred frequently in 1p-intact neuroblastoma, but may not consistently abrogate the function of bonafide 1p tumor suppressors. These findings may augment the evolving model of compounding contributions of 1p gene aberrations toward tumor suppressor inactivation in neuroblastoma. Keywords: Neuroblastoma, Chromosome 1, Tumor suppressor, Next-generation sequencing, Synchronous Mutations
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