Slabs in the lower mantle and their modulation of plume formation

Numerical mantle convection models indicate that subducting slabs can reach the core-mantle boundary (CMB) for a wide range of assumed material properties and plate tectonic histories. An increase in lower mantle viscosity, a phase transition at 660 km depth, depth-dependent thermal expansivity, and depth-dependent thermal diffusivity do not preclude model slabs from reaching the CMB. We find that ancient slabs could be associated with lateral temperature anomalies ~500°C cooler than ambient mantle. Plausible increases of thermal conductivity with depth will not cause slabs to diffuse away. Regional spherical models with actual plate evolutionary models show that slabs are unlikely to be continuous from the upper mantle to the CMB, even for radially simple mantle structures. The observation from tomography showing only a few continuous slab-like features from the surface to the CMB may be a result of complex plate kinematics, not mantle layering. There are important consequences of deeply penetrating slabs. Our models show that plumes preferentially develop on the edge of slabs. In areas on the CMB free of slabs, plume formation and eruption are expected to be frequent while the basal thermal boundary layer would be thin. However, in areas beneath slabs, the basal thermal boundary layer would be thicker and plume formation infrequent. Beneath slabs, a substantial amount of hot mantle can be trapped over long periods of time, leading to “mega-plume” formation. We predict that patches of low seismic velocity may be found beneath large-scale high seismic velocity structures at the core-mantle boundary. We find that the location, buoyancy, and geochemistry of mega-plumes will differ from those plumes forming at the edge of slabs. Various geophysical and geochemical implications of this finding are discussed

Modal analysis of micro wind turbine blade using COSMOSWorks

In this paper, vibration modal analysis of a horizontal axis micro wind turbine blade of different rotational speeds was carried out by using the finite element analysis software COSMOSWorks. The dynamic stiffening phenomenon and its effect on the vibration mode of the wind turbine blade were taken into account. Numerical results were analyzed and compared. The analysis can help not only to ensure the reliability of system operation but also to improve the structural performance

Comparison of Pulmonary Function Changes Between Patients Receiving Neoadjuvant Chemotherapy and Chemoradiotherapy Prior to Minimally Invasive Esophagectomy: A Randomized and Controlled Trial

PURPOSE: Adequate pulmonary function is important for patients undergoing surgical resection of esophageal cancer, especially those that received neoadjuvant therapy. However, it is unknown if pre-operative radiation affects pulmonary function differently compared to chemotherapy. The purpose of this study was to compare changes in pulmonary function between patients undergoing minimally invasive esophagectomy (MIE) who received neoadjuvant chemotherapy or chemoradiotherapy. METHODS: Between March 2017 and March 2018, esophageal cancer patients requiring neoadjuvant therapy were prospectively enrolled and randomly assigned to receive chemotherapy (CT) or chemoradiotherapy (CRT) before MIE. All patients received pulmonary function testing before and after the neoadjuvant therapy. Changes in pulmonary function, operative data, and pulmonary complications were compared between the 2 groups. RESULTS: A total of 71 patients were randomized and underwent MIE after receiving CT (n = 34) or CRT (n = 37). Baseline clinical characteristics were comparable between the 2 groups. The CRT group experienced a greater decrease of forced expiratory volume at 1 s (FEV CONCLUSIONS: Preoperative CRT affects pulmonary function more than CT alone, but does not increase the risk of pulmonary complications in patients undergoing MIE

Unveiling the spatial-temporal variation of urban land use efficiency of Yangtze River Economic Belt in China under carbon emission constraints

Under the constraint of carbon emission, measuring and analyzing the spatial-temporal evolution characteristics of urban land use efficiency in the Yangtze River Economic Belt is the inherent requirement of its ecological protection and sustainable development. In this paper, we calculated the urban land use efficiency of 107 cities in the Yangtze River Economic Belt from 2006 to 2020 by using the SBM-Undesirable model with unexpected output, and analyzed its temporal evolution trend and spatial correlation relationship by using kernel density and spatial autocorrelation method. The results showed that: except in 2020, the urban land use efficiency was generally low due to the COVID-19 epidemic, and the urban land use efficiency in other years was mostly concentrated in the middle levels, and showed a trend of slow fluctuation and rise year by year. The difference of urban land use efficiency level between regions increased, and the dispersion degree in upstream, midstream and downstream increased with each passing year. Urban land use efficiency spatial imbalance was significant, and the urban land use efficiency level of large and medium-sized cities was generally lower than that of cities with low economic development level. The spatial correlation was weak, and the global spatial autocorrelation was basically insignificant, while the local spatial agglomeration areas were mainly distributed in the upstream and downstream regions, with a small distribution range and weak spatial interaction. The distribution areas of the standard deviation ellipse were gradually flattened, and the center of gravity as a whole shift significantly to the southwest. The research results are helpful to understand the development history and future trend of urban land use efficiency in various regions, and propose that cities should consider the impact of public crisis events in advance, reasonably control the scale of land expansion, and lead coordinated development and other reasonable suggestions when formulating land use policies

Isosteviol Sensitizes sarcK ATP

KATP channel is an important mediator or factor in physiological and pathological metabolic pathway. Activation of KATP channel has been identified to be a critical step in the cardioprotective mechanism against IR injury. On the other hand, desensitization of the channel to its opener or the metabolic ligand ATP in pathological conditions, like cardiac hypertrophy, would decrease the adaption of myocardium to metabolic stress and is a disadvantage for drug therapy. Isosteviol, obtained by acid hydrolysis of stevioside, has been demonstrated to play a cardioprotective role against diseases of cardiovascular system, like anti-IR injury, antihypertension, antihyperglycemia, and so forth. The present study investigated the effect of isosteviol (STV) on sarcKATP channel current induced by pinacidil and mitochondrial flavoprotein oxidation induced by diazoxide. Our results showed that preincubating cells with STV not only increased the current amplitude and activating rate of sarcKATP channels induced by pinacidil but also potentiated diazoxide-elicited oxidation of flavoprotein in mitochondria

Genetic and environmental determinants of O6-methylguanine DNA-methyltransferase (MGMT) gene methylation: a 10-year longitudinal study of Danish twins

Background: Epigenetic inactivation of O6-methylguanine DNA-methyltransferase (MGMT) is associated with increased sensitivity to alkylating chemotherapeutic agents in glioblastoma patients. The genetic background underlying MGMT gene methylation may explain individual differences in treatment response and provide a clue to a personalized treatment strategy. Making use of the longitudinal twin design, we aimed, for the first time, to estimate the genetic contributions to MGMT methylation in a Danish twin cohort. Methods: DNA-methylation from whole blood (18 monozygotic (MZ) and 25 dizygotic (DZ) twin pairs) repeated 10 years apart from the Longitudinal Study of Aging Danish Twins (LSADT) were used to search for genetic and environmental contributions to DNA-methylation at 170 CpG sites of across the MGMT gene. Both univariate and bivariate twin models were applied. The intraclass correlations, performed on cross-sectional data (246 MZ twin pairs) from an independent study population, the Middle-Aged Danish Twins (MADT), were used to assess the genetic influence at each CpG site of MGMT for replication. Results: Univariate twin model revealed twelve CpG sites showing significantly high heritability at intake (wave 1, h2 > 0.43), and seven CpG sites with significant heritability estimates at end of follow-up (wave 2, h2 > 0.5). There were six significant CpG sites, located at the gene body region, that overlapped among the two waves (h2 > 0.5), of which five remained significant in the bivariate twin model, which was applied to both waves. Within MZ pair correlation in these six CpGs from MADT demarks top level of genetic influence. There were 11 CpGs constantly have substantial common environmental component over the 10 years. Conclusions: We have identified 6 CpG sites linked to the MGMT gene with strong and persistent genetic control based on their DNA methylation levels. The genetic basis of MGMT gene methylation could help to explain individual differences in glioblastoma treatment response and most importantly, provide references for mapping the methylation Quantitative Trait Loci (meQTL) underlying the genetic regulation.Peer reviewe

Evaluation of pathological complete response as a surrogate endpoint for overall survival in resectable oesophageal cancer:integrated analysis of individual patient data from phase III trials

Background Overall survival (OS) is the standard endpoint for oncological treatment efficacy, but requires long follow-up. The aim of this study was to evaluate pCR as a surrogate for OS in oesophageal cancer. Methods An integrated analysis of individual patient data (IPD) from phase III trials comparing perioperative therapies for resectable oesophageal and gastro-oesophageal junction cancer was conducted. Individual-level surrogacy between pCR and OS was assessed using Kendall's rank correlation coefficient (τ). A τ of 0.8 was considered a threshold for a good surrogate. As no method estimating τ between an ordinal endpoint and OS has been reported, a new method was proposed using the inverse-probability-of-censoring weighted estimator adjusted for tied data. Results Of 22 eligible trials, 10 provided IPD for 1641 patients, including 624 who received neoadjuvant chemotherapy (NAC; 45 (7.2%) achieved pCR) and 1017 who received neoadjuvant chemoradiotherapy (NACRT; 299 (29.4%) achieved pCR). In the NAC subgroup, patients with pCR had an HR for OS of 0.12 (95% c.i. 0.05 to 0.33), the C-index was 0.54 (95% c.i. 0.52 to 0.56), and τ was 0.256. In the NACRT subgroup, the HR was 0.57 (95% c.i. 0.47 to 0.70), the C-index was 0.56 (95% c.i. 0.54 to 0.58), and τ was 0.174. Hypothetical data suggested that achieving strong surrogacy (τ of 0.8) required an HR of 0.09 (95% c.i. 0.07 to 0.11). Conclusion Although pCR was correlated with OS, no evidence of individual-level surrogacy with OS was demonstrated, making it inappropriate to consider pCR as a surrogate endpoint for OS in resectable oesophageal cancer.</p

Efficacy of Baduanjin for obesity and overweight: a systematic review and meta-analysis

BackgroundAccording to data from the World Health Organization (WHO), there is a significant public health issue regarding the increasing number of individuals affected by obesity and overweight on an annual basis. Therefore, it is imperative to urgently identify interventions that can effectively control and improve this condition. Baduanjin, as a medium-intensity exercise, appears a suitable approach for weight reduction among individuals with obesity. This paper aimed to provide a systematic review and meta-analysis of the efficacy of Baduanjin in addressing obesity and overweight, with the ultimate goal of assisting individuals with obesity in finding an effective, safe, and engaging method for weight reduction.MethodsWe conducted a comprehensive search of multiple databases including PubMed, Cochrane Library, Web of Science, Embase, The China National Knowledge Infrastructure (CNKI), The Chinese Scientific Journal Database (VIP), The Chinese Biomedical Literature Database (CBM), and WanFang Database to identify relevant articles published from the inception of each database until September 2023. Specifically, we focused on randomized controlled trials (RCTs) investigating the effects of Baduanjin on weight reduction. Data from these studies were extracted and analyzed using appropriate statistical methods. In cases where there was no significant heterogeneity (I2 &lt; 50%, p &gt; 0.1), we employed a fixed effects model for data synthesis; otherwise, a random effects model was selected. Funnel plots were used to assess publication bias, and the mean difference (MD) was reported as an indicator of treatment group differences.ResultsA total of 420 participants were included in 10 studies. The MD results of the experimental group when compared with the control group were −3.69 (95%CI = −4.97 to −2.40, p &lt; 0.001) for body weight (BW), −5.42 (95%CI = −6.56 to −4.28, p &lt; 0.001) for body mass index (BMI), −1.36 (95%CI = −1.76 to −0.96, p &lt; 0.001) for waist circumference (WC), −3.40 (95%CI = −4.43 to −2.37, p &lt; 0.001) for hip circumference (HC), and −0.03 (95%CI = −0.04 to −0.02, p &gt; 0.1) for the waist-to-hip ratio (WHR). All of the values in the experimental group showed significant difference. The results of the Egger’s test (t = 1.43, p = 0.190) suggest that there was no substantial bias present within the data analysis process. The safety profile revealed no adverse events reported across all 10 studies.ConclusionBaduanjin could be effective in reducing weight, and the practice of Baduanjin has the potential to regulate BW, BMI, WC, HC, and WHR. However, further well-designed RCTs are still necessary to provide more robust evidence in the future.Systematic review registrationhttp://www.crd.york.ac.uk/PROSPERO/, identifier CRD42024513789

A primary amoebic meningoencephalitis case suspected to be infected by indoor swimming, China, 2024

IntroductionNaegleria fowleri causes Primary Amoebic Meningoencephalitis (PAM), an unusual but fatal disease. Swimming in wild freshwater is commonly regarded as the primary cause of infection. In April, 2024, we discovered a case of PAM in a child, suspected to have contracted the infection through an uncommon route: indoor swimming. This article describes the field epidemiological investigation process, the reasoning behind the speculation of the infection origin, and recommendations for minimizing potential risks.MethodsFace-to-face visit was conducted with the guardian of the case. Field investigations were carried out at suspected venues of infection. Reasonable inferences were made by combining literature and investigation results.ResultsThe case manifested typical PAM symptoms, followed by death 7 days after onset. The suspected exposure period was between March 4 and April 3, associated with several instances of swimming in two indoor pools. A field investigation at N Aquatic Center revealed improper disinfection methods, substandard water quality, and a suitable environment for Naegleria fowleri.DiscussionN Aquatic Center is the most likely source of infection after synthesizing epidemiological history, field investigation, and laboratory results. Individuals can get infected even when swimming indoors if the water is not well managed. Inspecting, monitoring, and disinfecting pool water should be strengthened

Pressure-induced tuning of lattice distortion in a high-entropy oxide

As a new class of multi-principal component oxides with high chemical disorder, high-entropy oxides (HEOs) have attracted much attention. The stability and tunability of their structure and properties are of great interest and importance, but remain unclear. By using in situ synchrotron radiation X-ray diffraction, Raman spectroscopy, ultraviolet–visible absorption spectroscopy, and ex situ high-resolution transmission electron microscopy, here we show the existence of lattice distortion in the crystalline (Ce$_{0.2}$La$_{0.2}$Pr$_{0.2}$Sm$_{0.2}$Y$_{0.2}$)O$_{2−δ }$ HEO according to the deviation of bond angles from the ideal values, and discover a pressureinduced continuous tuning of lattice distortion (bond angles) and band gap. As continuous bending of bond angles, pressure eventually induces breakdown of the long-range connectivity of lattice and causes amorphization. The amorphous state can be partially recovered upon decompression, forming glass–nanoceramic composite HEO. These results reveal the unexpected flexibility of the structure and properties of HEOs, which could promote the fundamental understanding and applications of HEOs