Patterns and driving forces of dimensionality-dependent charge density waves in 2H-type transition metal dichalcogenides

Two-dimensional (2D) materials have become a fertile playground for the exploration and manipulation of novel collective electronic states. Recent experiments have unveiled a variety of robust 2D orders in highly-crystalline materials ranging from magnetism to ferroelectricity and from superconductivity to charge density wave (CDW) instability. The latter, in particular, appears in diverse patterns even within the same family of materials with isoelectronic species. Furthermore, how they evolve with dimensionality has so far remained elusive. Here we propose a general framework that provides a unfied picture of CDW ordering in the 2H polytype of four isoelectronic transition metal dichalcogenides 2H-MX$_2$ (M=Nb, Ta and X=S, Se). We first show experimentally that whilst NbSe$_2$ exhibits a strongly enhanced CDW order in the 2D limit, the opposite trend exists for TaSe$_2$ and TaS$_2$, with CDW being entirely absent in NbS$_2$ from its bulk to the monolayer. Such distinct behaviours are then demonstrated to be the result of a subtle, yet profound, competition between three factors: ionic charge transfer, electron-phonon coupling, and the spreading extension of the electronic wave functions. Despite its simplicity, our approach can, in essence, be applied to other quasi-2D materials to account for their CDW response at different thicknesses, thereby shedding new light on this intriguing quantum phenomenon and its underlying mechanisms

Electrical switching of ferro-rotational order in nano-thick 1T-TaS2_2 crystals

Hysteretic switching of domain states is a salient character of all ferroic materials and the foundation for their multifunctional applications. Ferro-rotational order is emerging as a new type of ferroic order featuring structural rotations, but its controlled switching remains elusive due to its invariance under both time reversal and spatial inversion. Here, we demonstrate electrical switching of ferro-rotational domain states in nanometer-thick 1T-TaS$_2$ crystals in its charge-density-wave phases. Cooling from the high-symmetry phase to the ferro-rotational phase under an external electric field induces domain state switching and domain wall formation, realized in a simple two-terminal configuration using a volt-scale voltage. Although the electric field does not couple with the order due to symmetry mismatch, it drives domain wall propagation to give rise to reversible, durable, and nonvolatile isothermal state switching at room temperature. These results pave the path for manipulation of the ferro-rotational order and its nanoelectronic applications

Methylprednisolone as Adjunct to Endovascular Thrombectomy for Large-Vessel Occlusion Stroke

Importance It is uncertain whether intravenous methylprednisolone improves outcomes for patients with acute ischemic stroke due to large-vessel occlusion (LVO) undergoing endovascular thrombectomy. Objective To assess the efficacy and adverse events of adjunctive intravenous low-dose methylprednisolone to endovascular thrombectomy for acute ischemic stroke secondary to LVO. Design, Setting, and Participants This investigator-initiated, randomized, double-blind, placebo-controlled trial was implemented at 82 hospitals in China, enrolling 1680 patients with stroke and proximal intracranial LVO presenting within 24 hours of time last known to be well. Recruitment took place between February 9, 2022, and June 30, 2023, with a final follow-up on September 30, 2023.InterventionsEligible patients were randomly assigned to intravenous methylprednisolone (n = 839) at 2 mg/kg/d or placebo (n = 841) for 3 days adjunctive to endovascular thrombectomy. Main Outcomes and Measures The primary efficacy outcome was disability level at 90 days as measured by the overall distribution of the modified Rankin Scale scores (range, 0 [no symptoms] to 6 [death]). The primary safety outcomes included mortality at 90 days and the incidence of symptomatic intracranial hemorrhage within 48 hours. Results Among 1680 patients randomized (median age, 69 years; 727 female [43.3%]), 1673 (99.6%) completed the trial. The median 90-day modified Rankin Scale score was 3 (IQR, 1-5) in the methylprednisolone group vs 3 (IQR, 1-6) in the placebo group (adjusted generalized odds ratio for a lower level of disability, 1.10 [95% CI, 0.96-1.25]; P = .17). In the methylprednisolone group, there was a lower mortality rate (23.2% vs 28.5%; adjusted risk ratio, 0.84 [95% CI, 0.71-0.98]; P = .03) and a lower rate of symptomatic intracranial hemorrhage (8.6% vs 11.7%; adjusted risk ratio, 0.74 [95% CI, 0.55-0.99]; P = .04) compared with placebo. Conclusions and Relevance Among patients with acute ischemic stroke due to LVO undergoing endovascular thrombectomy, adjunctive methylprednisolone added to endovascular thrombectomy did not significantly improve the degree of overall disability.Trial RegistrationChiCTR.org.cn Identifier: ChiCTR210005172

Reproduction of: Retiring Adult - New Datasets for Fair Machine Learning (IS477)

<p>The paper discuesses the significant of the ethics and fairness of using dataset in machine learning. It discuesses the importance of using appropiate datasets in problem formation and problem solving. The paper then dive into a case in reality to get a futher analysis in the problem. It points out that in widely used UCI adults dataset, there are some limitations could have negatively impacted the fairness of the study, Ding et al. (2022). At the same time, it suggests that to address those limitations, we can use a new dataset derived from US Census data. At last, it also specify the variation within the population could also impact the study, so we need to deal with it carefully. That is the summary.</p><p>I would include both of the dataset in my project, because it can make the audience have more clear understanding of the project. But I would carefully cite the sources.</p&gt

Gene Set Enrichment Analysis and Genetic Experiment Reveal Changes in Cell Signaling Pathways Induced by α-Synuclein Overexpression

Abnormal accumulation of alpha synuclein (α-Syn) in sporadic and familial Parkinson’s disease (PD) may be a key step in its pathogenesis. In this study, the expression matrix of the GSE95427 dataset after α-Syn overexpression in human glioma cell line H4 was obtained from the GEO database. We used the Gene Set Enrichment Analysis (GSEA) method to reanalyze this dataset to evaluate the possible functions of α-Syn. The results showed that the tumor necrosis factor alpha (TNF-α) signal was significantly activated in α-Syn-overexpressing cells, and oxidative phosphorylation signal, extracellular matrix signal, cell cycle related signal and fatty acid metabolism signal were significantly inhibited. Moreover, we employed the α-Syn-expressing transgenic Drosophila model of Parkinson’s disease and knocked-down eiger, a TNF superfamily ligand homologue, indicating that the TNF-α pathway plays a role in the common pathogenesis of synucleinopathies. Our analysis based on GSEA data provides more clues for a better understanding of α-Syn function

Non-Additive Effects of Mixing Eucalyptus and Castanopsis hystrix Trees on Carbon Stocks under an Eco-Silviculture Regime in Southern China

Eucalyptus plantations harbor great potential for supporting ecosystem services, but this prospect is weakened under long-term traditional silviculture regimes. To reform these traditional silviculture regimes, we carried out a long-term Eucalyptus eco-silviculture experiment. However, the derived benefits and mechanisms that arise in mixed species stands under the eco-silviculture regime are not fully understood. Here, we evaluated tree carbon storage (TCS), understory vegetation carbon storage (UCS), floor litter carbon storage (FLCS), soil organic carbon storage (SOCS), and ecosystem carbon storage (ECS) in seven-year-old mono-specific plantations of a Eucalyptus hybrid (E. urophylla × E. grandis) and Castanopsis hystrix, as well as mixed plantations of these two trees under an eco-silviculture regime in southern China. The results showed that the tree height, diameter at breast height (DBH), volume, and biomass of eucalypt trees and C. hystrix in the mixed plantation were significantly higher than that of the trees in the corresponding single-species plantations. The mixed-species plantation had the largest TCS (84.33 Mg ha−1), FLCS (4.34 Mg ha−1), and ECS (313.31 Mg ha−1), as well as a higher SOCS (233.98 Mg ha−1), but the lowest UCS (0.96 Mg ha−1), among the three plantation types. The mixture effects analysis revealed significant synergistic effects (non-additive effect, NAE > 0) on TCS, SOCS, and ECS, and significant antagonistic effects (NAE < 0) on UCS. These synergistic effects were mainly due to the complementary ecological niches of the two species in the mixed-species plantation, which could potentially enable them to maximize the use of local resources, and to increase stand productivity and litter production. These results imply that beyond the gains in timber production obtained by having both Eucalyptus and C. hystrix trees growing in the same plantation stand, such mixed-species plantations enhance carbon sequestration to a greater extent than mono-specific plantations of either Eucalyptus or C.hystrix trees. In conclusion, we suggest planting mixed plantations of species with complementary ecological niches under an eco-silviculture regime, to effectively resolve the contradiction between timber production and ecosystem services, and, thereby, also promote the sustainable development of Eucalyptus plantations

Rainstorm-induced shallow landslides process and evaluation – a case study from three hot spots, China

The critical stage in the evaluation of rainfall-induced landslide failure is in formulating reasonable models to better simulate spatiotemporal changes of slopes in the hilly terrains. A physically based model can take into account the contribution of rainfall infiltration and shear strength of saturated soil layer, and therefore help revealing the landslide formation mechanisms. This paper presents a physically based approach to simulate the landslide process triggered by rainstorm. On the basis of previous solutions, we select the simplified infiltration model Slope-Infiltration-Distributed Equilibrium (SLIDE) to illustrate the dynamical relations between factor of safety (FS) and accumulation of rainfall over time. This model is tested with three representative landslide events in the southwest, southeast, and south central of China during rainstorm. Results show that the time of landslide failure predicted from the SLIDE model is consistent with the reality. Meanwhile, this paper illustrates the differences of FS among the different slope gradients in the vicinity of same soil texture and relationship between FS and rainfall accumulation. This work formulates a methodology of rainstorm-induced landslide evaluation and improves upon the existing landslide prediction methods

Influence of Climatic Factors and Soil Types on Seed Weight and Oil Content of Jatropha Curcas in Guangxi, China

AbstractThe seed weight and oil content of accessions of Jatropha curcas collected from 21 locations in different climatic zones of Guangxi province, China and their correlation with climatic factors and soil types were analyzed. There were significant differences (P<0.05) in 100-seed weight and oil content between locations. Maximum 100-seed weight was 71.0 in seeds collected from S21 and the minimum weight was 59.0 g in S10. Oil variability ranged from 34.10% in S12 to 55.50% in S21. The seed weight and oil content of J. curcas in acid soil types were significantly higher than those in calcium soil types. Seed weight and oil content were positively correlated with the mean annual sunshine duration (Sa), the mean annual temperature (Tmean), mean minimum daily temperature of the coldest month (Tmin), mean maximum daily temperature of the warmest month (Tmax) and the mean annual evaporation (Ea) (p<0.01), while were negatively correlated with altitude and the mean annual precipitation (Pa) (p<0.01). The ecological requirements of J. curcas are more fertile soil and more humid and have a higher Tmin than its commonly believed ecological requirements, and therefore point towards cautious selection of plantation sites, especially in karst and subtropical regions