Investigation on uniaxial compression and fracture damage mode of prefabricated parallel double-jointed red sandstone.

As a special type of joint fracture, the fracture evolution characteristics of parallel double joints have important engineering significance for the stability analysis of fractured rock mass. In this work, a new method for calculating stress intensity factor of parallel double-jointed fractures was importantly proposed. Physical uniaxial compression tests were carried out on parallel double jointed red sandstone filled with cement mortar under different geometric parameters, and the macroscopic mechanical properties and failure characteristics of red sandstone are deeply analyzed. The results show that the larger the connectivity rate is, the smaller the peak stress and strain are. The increase of connectivity rate will affect the change rate of transverse strain in the center of rock bridge. The closer the dip angle of the joint is, the lower the peak stress is and the shorter the failure time is. The damage mode of joint tip encroachment affects the lateral displacement of the rock bridge center, and the displacement is always close to the first damage section. The closer the joint tip is to the load, the easier the end-face penetrating cracks occur. The research content can provide basic support for guaranteeing the stability of underground engineering rock mass.

The Pharyngeal Packs for Dental and Otolaryngological Surgery: A Meta-Analysis of High-Quality Randomized Controlled Trials.

Background: Pharyngeal packs are employed to mitigate postoperative nausea and vomiting (PONV) and have become prevalent in dental and otolaryngological surgeries. However, their clinical efficacy continues to be a topic of debate. The objective of the present study was to conduct a quantitative assessment of the impact of pharyngeal packing in dental and otolaryngological surgeries through meta-analysis. Methods: We identified relevant randomized controlled trials (RCTs) through systematic searches of online databases, including PubMed, Embase, and Cochrane Central. Potential eligible studies were evaluated using the Jadad scoring system (range 0-5 points), with only high-quality RCTs (3 points or more) being included. The incidence of PONV, morbidity, and the level of throat pain were aggregated and estimated. Publication bias was evaluated using funnel plot symmetry and the Egger test. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) system was utilized to rate the evidence. Results: Ten high-quality RCTs comprising 1026 participants were ultimately included. Subsequent quantitative pooled estimation unveiled that the utilization of pharyngeal packing did not lead to a significant reduction in the incidence of nausea (P = .272), vomiting (P = .775), overall PONV (P = .118), or throat pain (P = .149). By contrast, the application of pharyngeal packs was found to significantly increase the level of throat pain (P = .003). No obvious publication bias was detected, and the majority of evidence was rated high or moderate. Conclusion: Based on the existing evidence, we conclude that pharyngeal packing lacks clinical benefit and is not advised for dental and otolaryngological surgeries.

The efficacy of gastric aspiration in reducing postoperative vomiting after oral and maxillofacial surgery: A meta-analysis.

BACKGROUND: Gastric aspiration is applied in oral and maxillofacial procedures to reduce postoperative vomiting (POV), yet its clinical benefit remains largely uncertain. Our study aimed to determine the role of gastric aspiration in the amelioration of POV by a meta-analysis. METHODS: With adherence to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, global recognized databases, including PubMed, Embase, and Cochrane Central, were searched to obtain randomized controlled trials (RCTs) investigating the effects of gastric aspiration in oral and maxillofacial surgery. The incidence and the number of episodes of POV and the frequency of rescue antiemetic use were extracted as parametric data for pooled estimation. Funnel plots and Egger's test were utilized to assess bias. The recommendation of evidence was rated by the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system. RESULTS: After detailed evaluation, 5 RCTs containing 274 participants were eventually included. The results of pooled estimation indicated that gastric aspiration could not reduce the incidence of POV (risk ratio [95% CI] = 0.94 [0.73, 1.21], P = .621), the number of episodes of POV (standard mean difference [95% CI] = -0.13 [-0.45, 0.19], P = .431) or the frequency of rescue antiemetic use (RR [95% CI] = 0.86 [0.49, 1.52], P = .609). No publication bias was detected by the funnel plot and Egger test. The overall recommendation of evidence was rated low regarding each outcome. CONCLUSION: Based on current evidence, gastric aspiration is not recommended for oral and maxillofacial surgery. Meanwhile, more large-scale high-quality RCTs are needed.

Effect of hyperbaric oxygen treatment on patients with heatstroke complicated by multiple organ dysfunction:A retrospective study.

Background: The benefits of hyperbaric oxygen (HBO) in treating animals with heat stroke (HS) have been established. This study aims to retrospectively analyze the effect of HBO on multiple organ dysfunction following HS in humans. Methods: Retrospective data were collected from patients with HS admitted to our hospital in the past 7 years. Patients were categorized into groups based on whether they received HBO therapy. The study compared various factors, including sequential organ failure assessment (SOFA) and acute physiology and chronic health evaluation-Ⅱ (APACHE-Ⅱ) scores, mortality rates, neurological function scores, serum myocardial enzyme levels, liver, kidney, and coagulation function indicators, blood routine results, electrolyte levels, and modified Barthel index (MBI) score for standard daily living ability before treatment and after 2 and 4 weeks of treatment. Results: The mortality rates in the HBO and control group were 0% and 8.49%, respectively. Upon admission, the HBO group had higher SOFA and APACHE-Ⅱ scores and lower neurological, coagulation, and liver functions than those of the control group. HBO treatment significantly improved SOFA, APACHE-Ⅱ, and neurological scores while relieving levels of alanine aminotransferase, aspartate aminotransferase, creatinine, and myocardial enzymes. Additionally, it mitigating lymphocyte and platelet count decline caused by HS. The MBI score was significantly enhanced after treatment in the HBO group. Conclusions: Clinical practice advocates administering HBO therapy to patients with severe illness, organ damage, and nerve impairment. Compared with conventional treatment, combined HBO therapy demonstrated superior efficacy in alleviating multiple organ dysfunction and improving daily living ability in patients with HS.

Prenatal LPS leads to increases in RAS expression within the PVN and overactivation of sympathetic outflow in offspring rats.

The renin-angiotensin system (RAS) and the sympathetic nervous system (SNS) are two major blood pressure-regulating systems. The link between the renal and cerebral RAS axes was provided by reflex activation of renal afferents and efferent sympathetic nerves. There is a self-sustaining enhancement of the brain and the intrarenal RAS. In this study, prenatal exposure to lipopolysaccharide (LPS) led to increased RAS activity in the paraventricular nucleus (PVN) and overactivation of sympathetic outflow, accompanied by increased production of reactive oxygen species (ROS) and disturbances between inhibitory and excitatory neurons in PVN. The AT1 receptor blocker losartan and α2 adrenergic receptor agonist clonidine in the PVN significantly decreased renal sympathetic nerve activity (RSNA) and synchronously reduced systolic blood pressure. Prenatal LPS stimulation caused H3 acetylation at H3K9 and H3K14 in the PVN, which suggested that epigenetic changes are involved in transmitting the prenatal adverse stimulative information to the next generation. Additionally, melatonin treatment during pregnancy reduced RAS activity and ROS levels in the PVN; balanced the activity of inhibitory and excitatory neurons in the PVN; increased urine sodium secretion; reduced RSNA and blood pressure. In conclusion, prenatal LPS leads to increased RAS expression within the PVN and overactivation of the sympathetic outflow, thereby contributing to hypertension in offspring rats. Melatonin is expected to be a promising agent for preventing prenatal LPS exposure-induced hypertension.