Causal structure and degenerate phase boundaries

Timelike and null hypersurfaces in the degenerate space-times in the Ashtekar theory are defined in the light of the degenerate causal structure proposed by Matschull. Using the new definition of null hypersufaces, the conjecture that the "phase boundary" separating the degenerate space-time region from the non-degenerate one in Ashtekar's gravity is always null is proved under certain circumstances.Comment: 13 pages, Revte

A Strategy Considering Both Magnitude and Duration of Drawdown

Drawdown is one of the most important measures to evaluate the risk of a portfolio. However, when it comes to the drawdown measure, the scholar’s concern more about the magnitude than the duration of the drawdown. For examples, there are various indicators of drawdown measures including the maximum drawdown, Conditional Drawdown-at-Risk (CDaR), etc. Most of them evaluate the magnitude of drawdown. In this paper, a strategy is built considering both the magnitude and duration of drawdown. Using the historical average maximum drawdown duration as the condition of filtering assets, this paper improves the strategy without considering the duration of the drawdown by leading an empirical analysis

Influence of pretreatment on properties of bamboo portland cement particle board

Bamboo contains water-soluble saccharides and carboxylic acid which have an anticoagulation effect on Portland cement, and the anticoagulation ingredients can directly influence the hydration reaction extent. Hydration product varieties and hydration product-bamboo shaving binding interfaces of the Portland cement, and finally the mechanical properties of bamboo cement particle boards. In this paper, bamboo shavings are pretreated by carbonizing treatment, hydro-thermal treatment and alkali treatment; highperformance liquid chromatography is adopted to analyze the influences of three different pretreatment methods on contents of water-soluble saccharides and carboxylic acid in the bamboo shavings; a Fourier infrared spectrometer and an X-ray diffractometer are respectively utilized to analyze the characteristic peak changes and crystallization property changes of chemical ingredients of the bamboo shavings before and after the three types of pretreatment.This paper discusses effects of three types of pretreatment methods in eliminating water-soluble saccharides and carboxylic acid in the bamboo shavings. Bamboo Portland cement particle boards was prepared using bamboo shavings, which are pretreated in three ways, and influences and mechanisms of different pretreatment methods on properties of the bamboo Portland cement particle boards were studied. Research indicates that the mechanical properties of the Portland cement particle board prepared from bamboo shavings pretreated with 3 % NaOH solution are superior to requirements of qualified products and superior products specified in the Standard GBT24312 (GB 2009)

Research on fault self-healing strategy of a distribution network considering wind and solar accommodation capacity

As a traditional fault recovery strategy, network reconfiguration changes the structure of a distribution network by changing the switching state to achieve a normal power supply for non-fault power loss. Distributed access, such as wind power and photovoltaics, will cause voltage and frequency fluctuations. Traditional tie switches cannot adapt to this change, which may lead to reconstruction failure. A flexible interconnection device can suppress the negative impact of these large-scale sources and loads with strong uncertainty and volatility on the power supply quality and system stability. This paper proposes a fault recovery strategy for a distribution network considering wind and solar consumption. First, through the analysis of the fault recovery process of a distribution network, it is proposed that the fault recovery of a distribution network can be realized by distribution network reconfiguration. Then, by analyzing the characteristics of the flexible interconnection device, it is shown that the flexible interconnection device can adapt well to the distribution network with new energy access. Finally, this paper constructs a multi-objective optimization reconfiguration model of a distribution network considering wind and solar consumption capacity and verifies the effectiveness of the scheme in improving wind and solar consumption capacity and solving economic problems through case analysis

EXPERIMENTAL STUDY ON INHIBITION OF S180 TUMOR CELLS BY AGRIMONIA PILOSA EXTRACT

We evaluated the in vitro and in vivo inhibition of S180 tumor cell growth of the water extract of Agrimonia pilosa. Inhibitory effect of Agrimonia pilosa on in vitro-cultured S180 cell proliferation was measured by MTT assay; mice model of transplanted tumor was established, after 8 days of continuous administration, the tumors were removed, weighed, and compared with the control group, and the in vivo anti-tumor effect of Agrimonia pilosa on mouse sarcoma S180 was compared using inhibition rate. The in vitro anti-tumor experiment indicated that the inhibition rate gradually increases with the increase of extract concentration and the extension of time, with IC50 175.64, 90.59, and 71.74 μg/ml at 24 h, 4 h, and 72 h respectively. In this study, the in vitro MTT assay was used to determine the inhibitory effect of Agrimony pilosa water extract on S180 tumor cells, the method is simple, reliable, and practical; mice model of in vivo transplanted S180 tumor was established, which allowed direct observation of tumor inhibitory effect, and thus found out that the water extract of Agrimonia pilosa has inhibitory effect on S180 tumor cells

Simplification of culture conditions and feeder-free expansion of bovine embryonic stem cells

Bovine embryonic stem cells (bESCs) extend the lifespan of the transient pluripotent bovine inner cell mass in vitro. After years of research, derivation of stable bESCs was only recently reported. Although successful, bESC culture relies on complex culture conditions that require a custom-made base medium and mouse embryonic fibroblasts (MEF) feeders, limiting the widespread use of bESCs. We report here simplified bESC culture conditions based on replacing custom base medium with a commercially available alternative and eliminating the need for MEF feeders by using a chemically-defined substrate. bESC lines were cultured and derived using a base medium consisting of N2B27 supplements and 1% BSA (NBFR-bESCs). Newly derived bESC lines were easy to establish, simple to propagate and stable after long-term culture. These cells expressed pluripotency markers and actively proliferated for more than 35 passages while maintaining normal karyotype and the ability to differentiate into derivatives of all three germ lineages in embryoid bodies and teratomas. In addition, NBFR-bESCs grew for multiple passages in a feeder-free culture system based on vitronectin and Activin A medium supplementation while maintaining pluripotency. Simplified conditions will facilitate the use of bESCs for gene editing applications and pluripotency and lineage commitment studies.Fil: Soto, Delia Alba. University of California at Davis; Estados UnidosFil: Navarro, Micaela. Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. - Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Biotecnológicas; Argentina. University of California at Davis; Estados UnidosFil: Zheng, Canbin. University of Texas. Southwestern Medical Center; Estados UnidosFil: Halstead, Michelle Margaret. University of California at Davis; Estados UnidosFil: Zhou, Chuan. University of California at Davis; Estados UnidosFil: Guiltinan, Carly. University of California at Davis; Estados UnidosFil: Wu, Jun. University of Texas. Southwestern Medical Center; Estados UnidosFil: Ross, Pablo Juan. University of California at Davis; Estados Unido

Three-Dimensional Self-Standing and Conductive MnCO3@Graphene/CNT Networks for Flexible Asymmetric Supercapacitors

The practical applications of flexible supercapacitor depend strongly on the successful fabrication of advanced electrode materials with high electrochemical performance. Herein, three-dimensional conductive network-based self-standing MnCO3@graphene/CNT hybrid film fabricated through a combination of a hydrothermal method and vacuum filtration for flexible solid-state supercapacitors is reported. The MnCO3@graphene structure is embedded in a CNT network, in which monodispersed MnCO3 nanorod is well confined in graphene nanosheets. This hierarchical structure provides rapid electron/electrolyte ion transport pathways and exhibits excellent structural stability, resulting in rapid kinetics and a long life cycle. The MnCO3@graphene/CNT electrode delivers high specific capacity (467.2 F g–1 at 1 A g–1). Asymmetric supercapacitor (ASC) devices are assembled with the MnCO3@graphene/CNT film as positive electrode and activated carbon/carbon cloth as negative electrode, which exhibits a high energy density of 27 W h kg–1. Remarkably, 93% capacitance retention is obtained for the ASC devices after 6000 cycles

MiR-501-3p/SPC24 axis affects cell proliferation, migration, invasion, apoptosis, and prognosis in renal cell carcinoma

It has been confirmed that the expression of miR-501-3p is closely related to the behavior of several cancers. This study aimed to elucidate the effects of miR-501-3p/SPC24 axis on the behavior of renal cancer cells and to identify its prognostic value in renal cancer. First, the expression of miR-501-3p in the renal cell carcinoma (RCC) cell line was detected using real-time quantitative polymerase chain reaction (RT-qPCR). Second, cell function identification experiments were performed, including CCK-8, scratch, transwell invasion, and flow cytometry assays. Several databases were applied to explore the possible mechanism of miR-501-3p tumor suppressor effect in RCC. To explore the value of miR-501-3p/SPC24 axis in predicting renal cancer patient overall survival (OS), GEPIA (http://gepia.cancer-pku.cn/index.html) was used. Finally, western blot was performed to detect the expression level of SPC24 in renal cancer cells predicted by bioinformatics analysis. Dual-Luciferase Reporter Assay was used to verify if SPC24 is a target of mir-501-3p. MiR-501-3p was found to be down-regulated in cancer cells and tissues and to play a role in suppressing tumor cell proliferation, cell viability, cell migration, and cell invasion, while promoting apoptosis. We also found that high expression levels of SPC24 were associated with shorter OS time in patients diagnosed with renal cell carcinoma. In addition, the results of TCGA data analysis and western blot showed that the tumor suppressor effect of miR-501-3p may be achieved by targeting SPC24. The MiR-501-3p/SPC24 axis affects cell proliferation, migration, invasion, apoptosis, and prognosis in renal cell carcinoma

Reduced abundance of Fusobacterium signifies cardiovascular benefits of sodium glucose cotransporter 2 inhibitor in type 2 diabetes: a single arm clinical trial

BackgroundThe sodium glucose cotransporter 2 inhibitor (SGLT2i) dapagliflozin has been demonstrated cardiovascular benefits in patients with type 2 diabetes mellitus (T2DM). However, the underlying mechanism remains poorly understood.MethodsWe conducted an 8-week, single-arm clinical trial, which enrolled 12 patients with inadequate glycemic control on metformin monotherapy. These patients were treated with SGLT2i dapagliflozin (10 mg/day). We assessed changes in clinical parameters pertinent to glucose metabolism and risk factors of cardiovascular disease (CVD), as well as alterations in the gut microbiota using macrogene sequencing.ResultsImprovements were observed in anthropometric parameters, glucose metabolism, blood lipid-related indices, inflammatory markers, and endothelial cell function-related parameters. Concurrently, SGLT2i led to changes in composition and functional pathways of the gut microbiota, manifested as increased abundance of probiotics and decreased abundance of harmful bacteria. Importantly, reduced abundance of Fusobacterium was correlated with improvements in various clinical indicators.ConclusionSGLT2i represents a superior initial therapeutic option for T2DM patients at risk of CVD. The cardiovascular benefits of SGLT2i may be attributed to shifts in the gut microbiota, particularly the reduced abundance of Fusobacterium