Risk correlation identification of futures market based on wavelet transform and quantile Granger causality test.

Futures market is an important part of the financial market, with a high degree of liquidity and leverage effect. However, the futures market is also faced with various risk factors, such as price fluctuations, market shocks, supply and demand changes. In order to better determine the risk correlation between specific futures markets, this paper uses the wavelet transform-quantile Granger causality test method to identify the risk correlation of four major futures markets in the US futures market from the end of January 2009 to the end of March 2023, such as gold, crude oil, soybeans and natural gas. It provides a new perspective and method for the risk correlation identification of the futures market. The results show that futures contracts with different maturities and price fluctuations under different quantiles have a significant impact on risk correlation. Specifically, in 1-month and 6-month futures contracts, the strongest bidirectional risk correlation exists between gold and natural gas (T-statistics -15.94 and 10.92, respectively); In the 1-month futures contract, there is also a strong bidirectional risk association between crude oil and soybeans and natural gas (T-statistics are 6.87, 17.42, -2.05, 7.35, respectively), while in the 6-month futures contract, there is a bidirectional risk association between crude oil and soybeans (T-statistics are -2.49 and 18.374, respectively). However, natural gas has unidirectional risk association with crude oil and soybean (t statistics are 2.7 and -3.35, respectively); There is a bidirectional risk correlation between gold and soybean, that is, the risk correlation between gold and soybean increases with the increase of the degree of price fluctuation; There is a one-way risk association between gold and crude oil, soybean and gold, and crude oil and natural gas (the T-statistic is greater than the critical value of 1.96). In addition, there is a strong bidirectional or unidirectional risk association between all varieties at the 0.95 quantile. The research results of this paper have certain reference value for the supervision, investment and risk management of the futures market. This paper uses the wavelet transform and quantile Granger causality test method to identify the risk correlation of the futures market, providing a new perspective and method for the risk correlation identification of the futures market, and uses relatively new data to ensure the effectiveness of the empirical analysis. However, there are some limitations in this paper, such as the applicability of wavelet transform-quantile Granger causality test method. Future studies can further expand the sample range, compare the effects of different methods, and explore the risk transmission mechanism between different varieties.

[Evaluation of the effect of simultaneous neuralized iliac bone flap on the preservation of lower lip and chin sensation during mandibular reconstruction].

PURPOSE: To evaluate the effect of reconstructing inferior alveolar nerve and preserving the sensation of lower lip and chin in repairing mandibular defect by simultaneous neuralized iliac bone flap. METHODS: Patients with continuous mandibular defects requiring reconstruction were randomly assigned to the innervated(IN) group and the control(CO) group by random number table. In the IN group, the deep circumflex iliac artery and recipient vessels were anastomosed microscopically during mandible reconstruction, and the ilioinguinal nerve(IN), mental nerve(MN) and inferior alveolar nerve(IAN) were anastomosed at the same time. In the CO group, only vascular anastomosis was performed without nerve reconstruction. During the operation, the nerve electrical activity after nerve anastomosis was detected by nerve monitor, and the sensory recovery of lower lip was recorded by two-point discrimination(TPD), current perception threshold (CPT) and Touch test sensory evaluator(TTSE) test. SPSS 26.0 software package was used for data analysis. RESULTS: According to the inclusion and exclusion criteria, a total of 20 patients were included, with 10 patients in each group. All the flaps survived in both groups, and no serious complications such as flap crisis occurred, and no obvious complications occurred in the donor site. The results of TPD test, CPT test and TTSE test all indicated that the degree of postoperative hypoesthesia in the IN group was less(P＜0.05). CONCLUSIONS: Simultaneous nerve anastomosis vascularized iliac bone flap can effectively preserve the feeling of lower lip and improve the postoperative quality of life of patients. It is a safe and effective technique.

Bisphosphorylation of anhydrides - convenient access to bisphosphonates with a P-O-C-P motif.

A novel strategy of bisphosphorylation of anhydrides with P(O)-H reagents via a DMAP-catalyzed and DBU-promoted process has been developed. These one-step transformations proceed efficiently to provide convenient access to a variety of P-O-C-P motif containing organophosphorus compounds. In addition, the gram-scale synthesis and the efficient recovery of the by-product highlight the sustainability and applicability of this method.

Neuroprotective Effect of Astragaloside IV on Cerebral Ischemia/Reperfusion Injury Rats Through Sirt1/Mapt Pathway.

Background: Ischemic stroke is a common disease with poor prognosis, which has become one of the leading causes of morbidity and mortality worldwide. Astragaloside IV (AS-IV) is the main bioactive ingredient of Astragali Radix (which has been used for ischemic stroke for thousands of years) and has been found to have multiple bioactivities in the nervous system. In the present study, we aimed to explore the neuroprotective effects of AS-IV in rats with cerebral ischemia/reperfusion (CIR) injury targeting the Sirt1/Mapt pathway. Methods: Sprague-Dawley rats (male, 250-280 g) were randomly divided into the Sham group, middle cerebral artery occlusion/reperfusion (MCAO/R) group, AS-IV group, MCAO/R + EX527 (SIRT1-specific inhibitor) group, and AS-IV + EX527 group. Each group was further assigned into several subgroups according to ischemic time (6 h, 1 d, 3 d, and 7 days). The CIR injury was induced in MCAO/R group, AS-IV group, MCAO/R + EX527 group, and AS-IV + EX527 group by MCAO surgery in accordance with the modified Zea Longa criteria. Modified Neurological Severity Scores (mNSS) were used to evaluate the neurological deficits; TTC (2,3,5-triphenyltetrazolium chloride) staining was used to detect cerebral infarction area; Western Blot was used to assess the protein levels of SIRT1, acetylated MAPT (ac-MAPT), phosphorylated MAPT (p-MAPT), and total MAPT (t-MAPT); Real-time Quantitative Polymerase Chain Reaction (qRT-PCR) was used in the detection of Sirt1 and Mapt transcriptions. Results: Compared with the MCAO/R group, AS-IV can significantly improve the neurological dysfunction (p < 0.05), reduce the infarction area (p < 0.05), raise the expression of SIRT1 (p < 0.05), and alleviate the abnormal hyperacetylation and hyperphosphorylation of MAPT (p < 0.05). While compared with the AS-IV group, AS-IV + EX527 group showed higher mNSS scores (p < 0.05), more severe cerebral infarction (p < 0.05), lower SIRT1 expression (p < 0.01), and higher ac-MAPT and p-MAPT levels (p < 0.05). Conclusion: AS-IV can improve the neurological deficit after CIR injury in rats and reduce the cerebral infarction area, which exerts neuroprotective effects probably through the Sirt1/Mapt pathway.

Individualized predictions of early isolated distal deep vein thrombosis in patients with acute ischemic stroke: a retrospective study.

BACKGROUND: Although isolated distal deep vein thrombosis (IDDVT) is a clinical complication for acute ischemic stroke (AIS) patients, very few clinicians value it and few methods can predict early IDDVT. This study aimed to establish and validate an individualized predictive nomogram for the risk of early IDDVT in AIS patients. METHODS: This study enrolled 647 consecutive AIS patients who were randomly divided into a training cohort (n = 431) and a validation cohort (n = 216). Based on logistic analyses in training cohort, a nomogram was constructed to predict early IDDVT. The nomogram was then validated using area under the receiver operating characteristic curve (AUROC) and calibration plots. RESULTS: The multivariate logistic regression analysis revealed that age, gender, lower limb paralysis, current pneumonia, atrial fibrillation and malignant tumor were independent risk factors of early IDDVT; these variables were integrated to construct the nomogram. Calibration plots revealed acceptable agreement between the predicted and actual IDDVT probabilities in both the training and validation cohorts. The nomogram had AUROC values of 0.767 (95% CI: 0.742-0.806) and 0.820 (95% CI: 0.762-0.869) in the training and validation cohorts, respectively. Additionally, in the validation cohort, the AUROC of the nomogram was higher than those of the other scores for predicting IDDVT. CONCLUSIONS: The present nomogram provides clinicians with a novel and easy-to-use tool for the prediction of the individualized risk of IDDVT in the early stages of AIS, which would be helpful to initiate imaging examination and interventions timely.

Gut Microbiota Disruption in Septic Shock Patients: A Pilot Study.

BACKGROUND The composition of the intestinal microbiota and its effect on septic shock patients in the intensive care unit (ICU) is unknown. In the present study we explored the hypothesis that bacterial diversity is decreased in septic shock patients and that this diversity may be improved by use of probiotics or enteral nutrition. MATERIAL AND METHODS A total of 15 stool samples were collected prospectively from septic shock patients in the ICU, while 15 samples from healthy subjects served as controls. Bacterial DNA was submitted for 16S rDNA gene sequencing. The relationship between intestinal microbiota and prognosis was evaluated. RESULTS Significantly lower bacterial diversity was found in septic shock patients compared with healthy subjects (p<0.05). However, there was no difference in bacterial diversity in the presence or absence of probiotics (p=0.59), enteral nutrition (p=0.59), or in-hospital death (p=0.93) in septic shock patients. A high abundance of Proteobacteria and Fusobacteria was observed in most septic shock patients, whereas low abundance was observed in healthy subjects (mean relative proportion: 23.71% vs. 3.53%, p<0.05; 1.27% vs. 0.12%, p=0.59). CONCLUSIONS Bacterial diversity was decreased, and 1 or 2 rare bacterial species were overgrown in septic shock patients. Bacterial diversity was not improved by use of probiotics or enteral nutrition. The small sample size of our study limits the interpretation of results.