571 research outputs found
A New Young Diagrammatic Method For Kronecker Products of O(n) and Sp(2m)
A new simple Young diagrammatic method for Kronecker products of O(n) and
Sp(2m) is proposed based on representation theory of Brauer algebras. A general
procedure for the decomposition of tensor products of representations for O(n)
and Sp(2m) is outlined, which is similar to that for U(n) known as the
Littlewood rules together with trace contractions from a Brauer algebra and
some modification rules given by King.Comment: Latex, 11 pages, no figure
Irisin Is Controlled by Farnesoid X Receptor and Regulates Cholesterol Homeostasis
ObjectiveThe aim of this study was to investigate whether the nuclear receptor farnesoid X receptor (FXR) could regulate FNDC5/Irisin expression and the role of Irisin in hyperlipidemia and atherosclerosis in ApoE-/- mice.Methods and ResultsWe treated primary human hepatocytes, HepG2 cells, and Rhesus macaques with FXR agonist (CDCA, GW4064, and ivermectin). FNDC5 expression was highly induced by CDCA and GW4064 in hepatocytes, HepG2 cells, and the circulating level of Irisin increased in Rhesus macaques. Luciferase reporter and CHIP assays were used to determine whether FXR could regulate FNDC5 promoter activity. Irisin-ApoE-/- and ApoE-/- mice were used to study the metabolic function of Irisin in dyslipidemia and atherosclerosis. Irisin-ApoE-/- mice showed improved hyperlipidemia and alleviated atherosclerosis as compared with ApoE-/- mice. Irisin upregulated the expression of Abcg5/Abcg8 in liver and intestine, which increased the transport of biliary cholesterol and fecal cholesterol output.ConclusionActivation of FXR induces FNDC5 mRNA expression in human and increased the circulating level of Irisin in Rhesus macaques. FNDC5/Irisin is a direct transcriptional target of FXR. Irisin may be a novel therapeutic strategy for dyslipidemia and atherosclerosis
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
Comprehensive Assessment of Geopolitical Risk in the Himalayan Region Based on the Grid Scale
The Himalayan region serves as a land bridge between China and South Asia but is vulnerable to geopolitical factors. It is important to conduct geopolitical risk assessments to facilitate the restoration and construction of traditional trade routes in the Himalayan region. Based on multisource natural, political, and socioeconomic data, we selected 12 indicators, including topographic relief, landslide risk, multi-hazard index, population density, territorial disputes, conflict risk, corruption perception index, transboundary water disputed risk, night light index, GDP, accessibility, and economic freedom, to assess these risks. A comprehensive assessment of the geopolitical risk in the Himalayan region is presented using the random forest (RF) model, analytic hierarchy process (AHP), entropy weight method, and AHP-entropy weight method. The results indicated that the geopolitical risk in the Himalayan region is generally high in the north and low in the south, with high level of risk primarily concentrated in the Kashmir valley and south, south-central Nepal and southern Tibet, and low level of risk mainly concentrated in the Bhutan and Tibet border areas of China. The high likelihood of natural risk is largely concentrated in the Indian states of Himachal Pradesh and Uttarakhand, Nepal, southeastern Bhutan, and southern Tibet. Significant political risk is mostly confined to the Kashmir valley and its south, while economic risk is mostly concentrated in Khyber-Pakhtunkhwa of Pakistan, Pakistani-administered regions of Kashmir, and Nepal. Geopolitical risk assessment based on the grid scale can better reveal and portray the spatial distribution of geopolitical risk in the Himalayan region and provide a basis for the restoration and construction of traditional trade routes in this region. According to the results of the geopolitical risk assessment, it is recommended that priority be given to construction in areas of relatively low risk, such as those close to Burang Country and Mustang, and that integrated planning be carried out for the restoration and construction of the predominantly low-risk trade routes between China and Bhutan, with further comprehensive analysis of each route conducted in conjunction with field surveys and proposed construction and control strategies
Reverse Trendelenburg Lithotomy with Certain Inclination Angles Reduces Stone Retropulsion during Ureteroscopic Lithotripsy for Proximal Ureteral Stone
The objective of this study is to investigate how different inclination angles of reverse Trendelenburg lithotomy affect stone retropulsion and stone-free rates during ureteroscopic lithotripsy for proximal ureteral stones. Patients with proximal ureteral stones undergoing ureteroscopic lithotripsy in our institution between January 2019 and December 2020 were included according to predefined criteria. The rigid ureteroscope and Holmium: YAG laser were utilized to perform lithotripsy, and a stone basket was used to keep the stone in place and to avoid retropulsion. Before initiating lithotripsy, the upper part of the patient’s body was tilted up to establish a reverse Trendelenburg posture with appropriate inclination angles. To quantify the stone-free rate, computed tomography was used to evaluate the residual stones in the kidney one month following surgery. Patients’ clinical data were obtained retrospectively, including age, gender, the largest diameter of stone, stone density on computed tomography, and the distance between stone and ureteral pelvic junction, etc. Patients were divided into four groups based on the inclination angles of reverse Trendelenburg lithotomy: 0°, 10°, 20°, and 30°. The chi-square test was used to compare stone retropulsion and stone-free rates between groups. To discover possible determinants of the stone-free rate, logistic regression analyses were used. There were 189 patients that qualified. There were no differences in clinical characteristics between groups (p > 0.05). Multiple comparisons between groups revealed that the 20° and 30° groups had less retropulsion and a greater stone-free rate than the 0° and 10° groups (p p > 0.05). The inclination angles as well as distance between the stone and ureteral pelvic junction were identified by using logistic regression analyses as the related factors for the stone-free rate. According to our results, the appropriate inclination angles of reverse Trendelenburg lithotomy during ureteroscopic lithotripsy for proximal ureteral stones would help preclude stone retropulsion and increase the stone-free rate
Spatial analysis of the driving factors of grassland degradation under conditions of climate change and intensive use in Inner-Mongolia, China
In recent years, steppe degradation in North China has become a serious environmental problem. Most research on steppe degradation is conducted at the level of communities or at the scale of small regions. To better understand the spatio-temporal variation and driving factors of grassland degradation, monitoring and analysis at broad regional scales are needed. This paper systematically describes the state and characteristics of steppe degradation at the Xilinhot plateau, makes an in-depth empirical analysis of the natural and man-made causes leading to degradation, and analyzes what driving factors have influenced degradation in this typical steppe region over the last 20 years. Ten biophysical and socio-economic variables, including altitude, slope, precipitation, temperature, soil conditions, distance to river, distance to highway, population density, sheep unit density, and fencing policy, were evaluated on their impact on observed patterns of degradation. The results indicate that all of these factors had a significant influence on the process of steppe degradation. During the first 10 years, from 1991 to 2000, steppe degradation increased, but after 2000, the degradation trend has, to some extent, reversed. The analysis indicates that the measures taken by the government, such as fencing vulnerable areas, played an important role in this change. The results advance the understanding of grassland degradation and contribute to constructing an empirical and theoretical base for grassland management and planning. © 2011 Springer-Verlag
A Method for Load Classification and Energy Scheduling Optimization to Improve Load Reliability
With the large amount of distributed generation in use, the structure of the distribution system is increasingly complex. Therefore, it is necessary to establish a method to improve load reliability. Based on the reliability model of distributed generation, this paper investigates the time sequential simulation of a wind/solar/storage combined power supply system under off-grid operation. After classifying the load by power supply region, the load weight coefficient is established, which modifies the reliability index of the load point and system. The modified expected energy not supplied (EENS) is adopted as the objective function, and the particle swarm optimization algorithm is used to solving the optimal energy scheduling for improving the load reliability. Finally, the load reliability is calculated with a hybrid method. Using the IEEE-RBTS Bus 6 system as an example, the correctness and validity of the proposed method are verified as an effective way to improve load reliability
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