Solid Dynamic Models for Analysis of Stress and Strain in Human Hearts

This paper proposes a solid model based on four-dimensional trivariate B-spline for strain and stress analysis of ventricular myocardium. With a series of processing steps in the four-dimensional medical images, the feature points of ventricular inner and outer wall are obtained. A B-spline surface is then used to build the dynamic deformation model of the myocardial walls. With such a surface model, a hexahedron control mesh can be constructed by sweeping the cloud data, and the ventricular solid model is built by fitting the trivariate B-spline parameters. Based on these models, a method of isogeometric analysis can be applied to calculate the stress and strain continuously distributed in the ventricle. The model is represented smoothly in the cylindrical coordinate system and is easy to measure myocardium dynamics for finding abnormal motion. Experiments are carried out for comparing the stress and strain distribution. It is found that the solid model can determine ventricular dynamics which can well reflect the deformation distribution in the heart and imply early clues of cardiac diseases

Effect of Scrophularia ningpoensis extract on diabetes in rats

Purpose: To investigate the effect of Scrophularia ningpoensis extract (SNE) on streptozotocin-induced diabetic rats.Methods: SNE was obtained by steeping the dried Scrophularia ningpoensis in water at 60 oC three times, each for 1 h, before first drying in an oven at 100 oC and then freeze-drying the last extract thus obtained. Diabetic rats were prepared by a single intraperitoneal injection of a freshly prepared solution of streptozotocin (50 mg/kg). The rats were randomly divided into 6 groups of ten rats each: negative control group, control group, reference group (glibenclamide1 mg/kgbody weight) as well as SNE groups, (50, 100 and 200 mg/kg). Blood glucose and plasma insulin levels were evaluated in order to determine antihyperglycemic effect. Oxidative stress was evaluated in liver and kidney by antioxidant markers, viz, lipid peroxidation (LPO), superoxide dismutase (SOD), reduced glutathione (GSH), glutathione peroxidase (GPx) and catalase (CAT); blood serum levels of creatinine and urea were determined in both diabetic control and treated rats.Results: Compared with diabetic rats, oral administration of SNE at a concentration of 200 mg/kg daily for 30 days showed a significant decrease in fasting blood glucose to 120.21 ± 3.37 mg/dL (p < 0.05) and increased insulin level to 13.31 ± 0.67 uU/mL (p < 0.05). Furthermore, it significantly reduced biochemical parameters (serum creatinine, 0.86 ± 0.24 mg/dL, p < 0.05) and serum urea (41.86 ± 1.59 mg/dL, p < 0.05).Conclusion: The results suggest that SNE may effectively normalize impaired antioxidant status in streptozotocin-induced diabetes in a dose-dependent manner. SNE has a protective effect against lipid peroxidation by scavenging free radicals and is thus capable of reducing the risk of diabetic complications.Keywords: Scrophularia ningpoensis, Diabetic, Antihyperglycemic, Antioxidant Oxidative stress, Fasting blood glucos

Multiple Unpinned Dirac Points in Group-Va Single-layers with Phosphorene Structure

Emergent Dirac fermion states underlie many intriguing properties of graphene, and the search for them constitute one strong motivation to explore two-dimensional (2D) allotropes of other elements. Phosphorene, the ultrathin layers of black phosphorous, has been a subject of intense investigations recently, and it was found that other group-Va elements could also form 2D layers with similar puckered lattice structure. Here, by a close examination of their electronic band structure evolution, we discover two types of Dirac fermion states emerging in the low-energy spectrum. One pair of (type-I) Dirac points is sitting on high-symmetry lines, while two pairs of (type-II) Dirac points are located at generic $k$-points, with different anisotropic dispersions determined by the reduced symmetries at their locations. Such fully-unpinned (type-II) 2D Dirac points are discovered for the first time. In the absence of spin-orbit coupling, we find that each Dirac node is protected by the sublattice symmetry from gap opening, which is in turn ensured by any one of three point group symmetries. The spin-orbit coupling generally gaps the Dirac nodes, and for the type-I case, this drives the system into a quantum spin Hall insulator phase. We suggest possible ways to realize the unpinned Dirac points in strained phosphorene.Comment: 30 pages, 6 figure

Policy assessments for the carbon emission flows and sustainability of Bitcoin blockchain operation in China

The growing energy consumption and associated carbon emission of Bitcoin mining could potentially undermine global sustainable efforts. By investigating carbon emission flows of Bitcoin blockchain operation in China with a simulation-based Bitcoin blockchain carbon emission model, we find that without any policy interventions, the annual energy consumption of the Bitcoin blockchain in China is expected to peak in 2024 at 296.59 Twh and generate 130.50 million metric tons of carbon emission correspondingly. Internationally, this emission output would exceed the total annualized greenhouse gas emission output of the Czech Republic and Qatar. Domestically, it ranks in the top 10 among 182 cities and 42 industrial sectors in China. In this work, we show that moving away from the current punitive carbon tax policy to a site regulation policy which induces changes in the energy consumption structure of the mining activities is more effective in limiting carbon emission of Bitcoin blockchain operation

Changes in global climate heterogeneity under the 21st century global warming

Publisher Copyright: © 2021 The Author(s)Variations in climate types are commonly used to describe changes in natural vegetation cover in response to global climate change. However, few attempts have been made to quantify the heterogeneous dynamics of climate types. In this study, based on the Coupled Model Intercomparison Project phase 5 (CMIP5) historical and representative concentration pathway (RCP) runs from 18 global climate models, we used Shannon's Diversity Index (SHDI) and Simpson's Diversity Index (SIDI) to characterise of global climate heterogeneity from a morphological perspective. Our results show that global climate heterogeneity calculated by the SHDI/SIDI indices decreased from 1901 to 2095 at a significance level of 0.01. As radiative forcing intensified from RCP 2.6 to 8.5, the SHDI/SIDI decreased significantly. Furthermore, we observed that the spatial distribution of global climate heterogeneity was significantly reduced, with a pronounced latitudinal trend. Sensitivity analysis indicated that the temperature increase played a more significant role in reducing global climate heterogeneity than precipitation under the three warming scenarios, which is possibly attributed to anthropogenic forcing. Our findings suggest that the dynamics of global climate heterogeneity can be an effective means of quantifying global biodiversity loss.Peer reviewe

Observed Changes of Koppen Climate Zones Based on High-Resolution Data Sets in the Qinghai-Tibet Plateau

Emerging and disappearing climate zones are frequently used to diagnose and project climate change. However, little attempt has been made to quantify shifts of climate zones in Qinghai-Tibet Plateau (QTP) based on the high-resolution data sets. Our results show that highland climate was decreased substantially during 1961–2011 and were mainly replaced by boreal climate. We also found that the mean elevation of boreal and highland climate continues to rise, with obvious longitudinal geographical characteristics over the study period. Furthermore, we found that the climate spaces (a climate space defined as the volume of 10°C × 500 mm here) of both boreal and highland climate types tend to be warm and humid ones, which may provide more suitable climate conditions for species to maintain and promote diversity. Characterization of changes in QTP climate types deepens our understanding of regional climate and its biological impacts.Emerging and disappearing climate zones are frequently used to diagnose and project climate change. However, little attempt has been made to quantify shifts of climate zones in Qinghai-Tibet Plateau (QTP) based on the high-resolution data sets. Our results show that highland climate was decreased substantially during 1961-2011 and were mainly replaced by boreal climate. We also found that the mean elevation of boreal and highland climate continues to rise, with obvious longitudinal geographical characteristics over the study period. Furthermore, we found that the climate spaces (a climate space defined as the volume of 10 degrees C x 500 mm here) of both boreal and highland climate types tend to be warm and humid ones, which may provide more suitable climate conditions for species to maintain and promote diversity. Characterization of changes in QTP climate types deepens our understanding of regional climate and its biological impacts. Plain Language Summary Climate classification is the key to simplifying complex climate and helps to deepen the understanding of regional climate change. Based on the high-resolution data set (LZ0025), the sharp climatic gradient features and their potential biological impact on Qinghai-Tibet Plateau (QTP) was quantified. With the temperature increase, the spatial distribution of highland tundra climate was gradually replaced by boreal climate. More importantly, the contraction of highland climate and the expansion of boreal climate has obvious elevation characteristics. In addition, climate spaces of highland and boreal climate types tend to warm and humid ones, which may provide more climatic niches for different species and contribute to regional biodiversity.Peer reviewe

From a Spatial Structure Perspective : Spatial-Temporal Variation of Climate Redistribution of China Based on the Köppen–Geiger Classification

https://doi.org/10.1029/2022GL099319Shifting climate zones are widely used to diagnose and predict regional climate change. However, few attempts have been made to measure the spatial redistribution of these climate zones from a spatial structure perspective. We investigated changes in spatial structure of Köppen climate landscape in China between 1963 and 2098 with a landscape aggregation index. Our results reveal an apparent signal from fragmentation to aggregation, accompanied by the intensification of areal dispersion between cold and warm climate types. Our attribution analysis indicates that anthropogenic forcings have a larger influence on changes of spatial structure than natural variation. We also found that topographical heterogeneity is likely to contribute to the regional spatial fragmentation, especially in the Qinghai-Tibet Plateau. However, we also found that the spatial fragmentation will be weakened around the mid-2040s. We argue that biodiversity is likely to be mediated by spatial structure of future climate landscapes in China.Peer reviewe

Vegetation response to climate zone dynamics and its impacts on surface soil water content and albedo in China

Extensive research has focused on the response of vegetation to climate change, including potential mechanisms and resulting impacts. Although many studies have explored the relationship between vegetation and climate change in China, research on spatiotemporal distribution changes of climate regimes using natural vegetation as an indicator is still lacking. Further, limited information is available on the response of vegetation to shifts in China's regional climatic zones. In this study, we applied Mann-Kendall, and correlation analysis to examine the variabilities in temperature, precipitation, surface soil water, normalised difference vegetation index (NDVI), and albedo in China from 1982 to 2012. Our results indicate significant shifts in the distribution of Koppen-Geiger climate classes in China from 12.08% to 18.98% between 1983 and 2012 at a significance level of 0.05 (MK). The percentage areas in the arid and continental zones expanded at a rate of 0.004%/y and 0.12%/y, respectively, while the percentage area in the temperate and alpine zones decreased by -0.05%/y and - 0.07%/y. Sensitivity fitting results between simulated and observed changes identified temperature to be a dominant control on the dynamics of temperate (r(2)= 0.98) and alpine (r(2)= 0.968) zones, while precipitation was the dominant control on the changes of arid (r(2) = 0.856) and continental (r(2) = 0.815) zones. The response of the NDVI to albedo infers a more pronounced radiative response in temperate (r = -0.82, pPeer reviewe

TiEV: The Tongji Intelligent Electric Vehicle in the Intelligent Vehicle Future Challenge of China

TiEV is an autonomous driving platform implemented by Tongji University of China. The vehicle is drive-by-wire and is fully powered by electricity. We devised the software system of TiEV from scratch, which is capable of driving the vehicle autonomously in urban paths as well as on fast express roads. We describe our whole system, especially novel modules of probabilistic perception fusion, incremental mapping, the 1st and the 2nd planning and the overall safety concern. TiEV finished 2016 and 2017 Intelligent Vehicle Future Challenge of China held at Changshu. We show our experiences on the development of autonomous vehicles and future trends

Features and Prognostic Value of Quantitative Electroencephalogram Changes in Critically Ill and Non-critically Ill Anti-NMDAR Encephalitis Patients: A Pilot Study

Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is a common cause of encephalitis in intensive care units. Until now, no reliable method has existed for predicting the outcome of anti-NMDAR encephalitis. In this study, we used quantitative electroencephalography (qEEG) to examine the brain function of anti-NMDAR encephalitis patients and assessed its predictive value. Twenty-six patients diagnosed with anti-NMDAR encephalitis were included and grouped according to whether they were treated in intensive care units (14 critically ill vs. 12 non-critically ill). All patients underwent 2-h 10-channel qEEG recordings at the acute stage. Parameters, including amplitude-integrated electroencephalogram (aEEG), spectral edge frequency 95%, total power, power within different frequency bands (δ, θ, α, and β), and percentages of power in specific frequency bands from frontal and parietal areas were calculated with NicoletOne Software and compared between groups. The short-term outcome was death or moderate/severe disability at 3 months after onset, measured with a modified Rankin Scale, and the long-term outcome was death, disability or relapse at 12 months. No differences in qEEG parameters were observed between the critically ill and non-critically ill patients. However, differential anterior-to-posterior alterations in δ and β absolute band power were observed. Logistic regression analysis revealed that a narrower parietal aEEG bandwidth was associated with favorable long-term outcomes (odds ratio, 37.9; P = 0.044), with an optimal cutoff value of 1.7 μV and corresponding sensitivity and specificity of 90.00 and 56.25%, respectively. In a receiver operating characteristic analysis, the area under the curve was 0.7312. In conclusion, the qEEG parameters failed to reflect the clinical severity of anti-NMDAR encephalitis. However, the parietal aEEG bandwidth may separate patients with favorable and poor long-term outcomes in early stages. The underlying mechanisms require further investigation