Ursolic acid attenuates pseudo-allergic reactions via reducing MRGPRX2-mediated mast cell degranulation.

Mas-related G protein-coupled receptor X2 (MRGPRX2) is a newly identified receptor on mast cells that contribute to IgE-independent pseudo-allergy. Ursolic acid (UA), a pentacyclic triterpenoid, has been reported for its anti-allergy effects. However, the protective mechanism against pseudo-allergic reactions remains unclear. This study aims to investigate the effects of UA on pseudo-allergic reactions both in vivo and in vitro, focusing on the therapeutical mechanism underlying its effect on mast cells. In present study, UA reduced degranulation and chemokines production induced by MRGPRX2 agonists, including compound 48/80 (C48/80) and substance P (SP), in LAD2 cells in vitro. UA also alleviated C48/80 and SP-induced systemic anaphylaxis and passive cutaneous anaphylaxis (PCA) in vivo. Furthermore, UA demonstrated strong binding affinity to the MRGPRX2 protein, leading to a decrease in calcium influx in both LAD2 cells and MRGPRX2-HEK293 cells stimulated with C48/80 and SP. Moreover, UA effectively suppressed phosphorylation levels within phospholipase C-γ (PLCγ) pathway and nuclear factor kappa-B (NF-κB) pathway of MRGPRX2 downstream proteins. Our findings indicated that UA exerts an attenuating effect in pseudo-allergic reactions by suppressing MRGPRX2-mediated mast cell activation, targeting PLCγ pathway and NF-κB pathway. These results suggest that UA may serve as a promising therapeutic agent for MRGPRX2-dependent pseudo-allergic reactions.

Novel mutations in LRRC23 cause asthenozoospermia in a nonconsanguineous family.

ABSTRACT: The cause of asthenozoospermia (AZS) is not well understood because of its complexity and heterogeneity. Although some gene mutations have been identified as contributing factors, they are only responsible for a small number of cases. Radial spokes (RSs) are critical for adenosine triphosphate-driven flagellar beating and axoneme stability, which is essential for flagellum motility. In this study, we found novel compound heterozygous mutations in leucine-rich repeat-containing protein 23 ( LRRC23 ; c.1018C>T: p.Q340X and c.881_897 Del: p.R295Gfs*32) in a proband from a nonconsanguineous family with AZS and male infertility. Diff-Quik staining and scanning electron microscopy revealed no abnormal sperm morphology. Western blotting and immunofluorescence staining showed that these mutations suppressed LRRC23 expression in sperm flagella. Additionally, transmission electron microscopy showed the absence of RS3 in sperm flagella, which disrupts stability of the radial spoke complex and impairs motility. Following in vitro fertilization and embryo transfer, the proband's spouse achieved successful pregnancy and delivered a healthy baby. In conclusion, our study indicates that two novel mutations in LRRC23 are associated with AZS, but successful fertility outcomes can be achieved by in vitro fertilization-embryo transfer techniques.

Multicenter propensity score-matched analysis to compare perioperative morbidity after laparoscopic or robotic complex hepatectomy for solitary hepatocellular carcinoma.

BACKGROUND: Postoperative complications are vital factors affecting the prognosis of patients with hepatocellular carcinoma (HCC), especially for complex hepatectomy. The present study aimed to compare perioperative complications between laparoscopic and robotic complex hepatectomy (LCH vs. RCH). METHODS: Patients with solitary HCC after complex hepatectomy were collected from a multicenter database. Propensity score-matched (PSM) analysis was adopted to control confounding bias. Multivariable analysis was performed to determine the prognostic factors. RESULTS: 436 patients were included. After PSM, 43 patients were included in both the LCH and RCH groups. The results showed that compared to LCH, RCH had lower rates of blood loss and transfusion, and lower postoperative 30-day and major morbidity, and post-hepatectomy liver failure (PHLF) (all P < 0.05). Additionally, the length of hospital stay was shorter in the RCH group (P = 0.026). Multivariable analysis showed RCH is an independent protective factor for reducing the 30-day morbidity, major morbidity and PHLF. CONCLUSION: RCH has advantages over LCH in the minimally invasive treatment of complex HCC, as it can reduce the incidence of postoperative morbidity. Therefore, RCH should be considered for patients with HCC who require complex hepatectomy.

Precise planning based on 3D-printed dry-laboratory models can reduce perioperative complications of laparoscopic surgery for complex hepatobiliary diseases: a preoperative cohort study.

BACKGROUND & AIMS: Complications after laparoscopic liver resection (LLR) are important factors affecting the prognosis of patients, especially for complex hepatobiliary diseases. The present study aimed to evaluate the value of a three-dimensional (3D) printed dry-laboratory model in the precise planning of LLR for complex hepatobiliary diseases. METHODS: Patients with complex hepatobiliary diseases who underwent LLR were preoperatively enrolled, and divided into two groups according to whether using a 3D-printed dry-laboratory model (3D vs. control group). Clinical variables were assessed and complications were graded by the Clavien-Dindo classification. The Comprehensive Complication Index (CCI) scores were calculated and compared for each patient. Multivariable analysis was performed to determine the risk factors of postoperative complications. RESULTS: Sixty-two patients with complex hepatobiliary diseases underwent the precise planning of LLR. Among them, thirty-one patients acquired the guidance of a 3D-printed dry-laboratory model, and others were only guided by traditional enhanced CT or MRI. The results showed no significant differences between the two groups in baseline characters. However, compared to the control group, the 3D group had a lower incidence of intraoperative blood loss, as well as postoperative 30-day and major complications, especially bile leakage (all P < 0.05). The median score on the CCI was 20.9 (range 8.7-51.8) in the control group and 8.7 (range 8.7-43.4) in the 3D group (mean difference, -12.2, P = 0.004). Multivariable analysis showed the 3D model was an independent protective factor in decreasing postoperative complications. Subgroup analysis also showed that a 3D model could decrease postoperative complications, especially for bile leakage in patients with intrahepatic cholelithiasis. CONCLUSION: The 3D-printed models can help reduce postoperative complications. The 3D-printed models should be recommended for patients with complex hepatobiliary diseases undergoing precise planning LLR.

Survival benefit from adjuvant TACE combined with Lenvatinib for patients with hepatocellular carcinoma and microvascular invasion after curative hepatectomy.

BACKGROUND AND AIMS: The prognosis of patients with hepatocellular carcinoma (HCC) undergoing hepatectomy is unsatisfactory, especially for those with microvascular invasion (MVI). This study aimed to determine the impact of adjuvant transcatheter arterial chemoembolization (TACE) and Lenvatinib on the prognosis of patients with HCC and MVI after hepatectomy. METHODS: Patients diagnosed with HCC and MVI were reviewed, and stratified into four groups according to adjuvant TACE and/or Lenvatinib. Multivariate Cox regression analyses are used to determine independent risk factors. RESULTS: 346 patients were included, and divided into four groups (Group I, TACE+ Lenvatinib; Group II, Lenvatinib; Group III, TACE; Group IV, without adjuvant therapy). Multivariable analysis showed that compared to Group IV, Group I had the best effect on improving the overall survival (OS, HR 0.321, 95%CI 0.099-0.406, P = 0.001) and recurrence-free survival (RFS, HR 0.319, 95%CI 0.129-0.372, P = 0.001). Additionally, compared with Group II or Group III, Group I also can significantly improve the OS and RFS. There is no significant difference between Group II and Group III in OS and RFS. CONCLUSION: The combination of TACE and Lenvatinib should be considered for anti-recurrence therapy for patients with HCC and MVI after hepatectomy.

Preoperative Antiviral Therapy and Long-Term Outcomes for Hepatitis B Virus-Related Hepatocellular Carcinoma After Curative Liver Resection: A Multicenter Analysis.

Background & Aims: To examine the association of the history of preoperative antiviral therapy (AVT) with the tumor recurrence and overall survival in HBV-related HCC patients undergoing curative-intent hepatectomy. Methods: Patients who underwent curative-intent hepatectomy for HBV-related HCC between 2014 and 2019 at 4 Chinese hospitals were analyzed. Patients were categorized as having undergone preoperative antiviral therapy (AVT) > 1 year or without antiviral therapy (non-AVT). Patient clinical features, short-term outcomes, overall survival (OS), and time-to-recurrence (TTR) were also compared. Multivariate Cox regression analysis was performed to identify the impact of preoperative AVT on the OS and TTR. Results: Among the 565 patients, 190 (33.6%) underwent continuous AVT > 1 year before surgery. Patients in the non-AVT group were more likely to have worse liver function and more advanced tumor pathological characteristics than those in the AVT group. Postoperative morbidity and mortality rates were comparable between the two groups. Multivariate analyses revealed that a preoperative HBV viral level ≥ 2000 IU/mL was independently associated with poorer TTR (hazard ratio, 1.328; 95% CI, 1.049-1.682) and preoperative AVT was a protective factor for OS (hazard ratio, 0.691; 95% CI, 0.484-0.986). Conclusion: A high preoperative HBV DNA level was an independent risk factor for tumor recurrence. Preoperative AVT > 1 year was associated with better OS and a reduced incidence of tumor recurrence by inhibiting the preoperative level of HBV DNA.

Homochiral and Heterochiral Self-Sorting Assemblies of Antiaromatic Ni(II) Norcorrole Dimers.

Recently, π-π stacked antiaromatic π-systems have received considerable attention because they can exhibit stacked-ring aromaticity due to substantial intermolecular orbital interactions. Here, we report three antiaromatic norcorrole dimers that self-assemble to form supramolecular architectures through chiral self-sorting. A 2,2'-linked norcorrole dimer with 3,5-di-tert-butylphenyl groups forms a π-stacked dimer both in solid and solution states via homochiral self-sorting. Its association constant in solution is (3.6±1.7)×105 M-1 at 20 °C. In the solid state, 3,3'-linked norcorrole dimers with 3,5-di-tert-butylphenyl and phenyl groups afford macrocyclic and helical supramolecular assemblies via heterochiral and homochiral self-sorting, respectively. Notably, the subtle modification in the substituent resulted in a complete change in the structure of the aggregates and the chiral self-sorting mode. The present findings demonstrate that structural manipulation in antiaromatic monomer units leads to the formation of various supramolecular assemblies on the basis of the attractive interactions between antiaromatic π-systems.

Adrenomedullin improved endothelial dysfunction via receptor-Akt pathway in rats with obesity-related hypertension.

Obesity-related hypertension (OH) is accompanied by obvious endothelial dysfunction, which contributes to increased peripheral vascular resistance and hypertension. Adrenomedullin (ADM), a multifunctional active peptide, is elevated in obese humans. The OH rats induced by high fat diet (HFD) for 28 weeks and the human umbilical vein endothelial cells (HUVECs)-treated by palmitic acid (PA) were used to investigate the effects of ADM on endothelial dysfunction and the underlying mechanisms. Vascular reactivity was assessed using mesenteric arteriole rings, and the protein expression levels were examined by Western blot analysis. Compared with the control rats, OH rats exhibited hypertension and endothelial dysfunction, along with reduced eNOS protein expression and Akt activation, and increased protein expression of proinflammatory cytokines and ROS levels. Four-week ADM administration improved hypertension and endothelial function, increased eNOS protein expression and Akt activation, and attenuated endothelial inflammation and oxidative stress in OH rats. In vitro experiment, the antagonism of ADM receptors with ADM22-52 and the suppression of Akt signaling with A6730 significantly blocked ADM-caused increase of NO content and activation of eNOS and Akt, and inhibited the anti-inflammatory and anti-oxidant effect of ADM in PA-stimulated HUVECs. These data indicate that endothelial dysfunction in OH rats is partially attributable to the decreased NO level, and the increased inflammation and oxidative stress. ADM improves endothelial function and exerts hypotensive effect depending on the increase of NO, and its anti-inflammatory and anti-oxidant effect via receptor-Akt pathway.

[Age-dependent expression of HSP90 in the hippocampus of APP/PS1 mice].

The present study aims to observe the change in expression of heat shock protein 90 (HSP90) along with amyloid-ß (Aß) and phosphorylated Tau (p-Tau) protein levels in the hippocampus tissue of Alzheimer's disease (AD) transgenic animal model with age. APP/PS1 transgenic mice at age of 6-, 9- and 12-month and C57BL/6J mice of the same age were used. The cognitive abilities of these animals were evaluated using a Morris water maze. Western blot or immunohistochemistry was used to detect the expressions of HSP90 and Aß1-42, as well as the phosphorylation levels of Tau protein in the hippocampus. The hsp90 mRNA levels and the morphology and number of cells in the hippocampus were detected with real-time quantitative polymerase chain reaction (qRT-PCR) and Nissl staining, respectively. The results showed that compared with C57BL/6J mice of the same age, HSP90 and hsp90 mRNA expression were decreased (P < 0.05 or P < 0.01), while Aß1-42 and p-Tau protein levels were increased (P < 0.05 or P < 0.01) in the hippocampal tissue of APP/PS1 transgenic mice. Meanwhile, the decrease in HSP90 and hsp90 mRNA expression (P < 0.05 or P < 0.01), the increase in Aß1-42 and p-Tau levels (P < 0.01 or P < 0.05) in hippocampal tissue and the reduction in behavioral ability showed a progressive development with the advancing of age in the APP/PS1 transgenic mice. In conclusion, in the hippocampal tissue of APP/PS1 mice, the decrease in HSP90 expression and the increase in Aß1-42 and p-Tau levels together with the decline of their cognitive ability are age-dependent.

An Observational Prospective Cohort Study of Vaccine Effectiveness Against Severe Acute Respiratory Syndrome Coronavirus 2 Infection of an Aerosolized, Inhaled Adenovirus Type 5-Vectored Coronavirus Disease 2019 Vaccine Given as a Second Booster Dose in Guangzhou City, China.

Using a prospective, observational cohort study during the post-"dynamic COVID-zero" wave in China, we estimated short-term relative effectiveness against Omicron BA.5 infection of inhaled aerosolized adenovirus type 5-vectored ancestral strain coronavirus disease 2019 (COVID-19) vaccine as a second booster dose approximately 1 year after homologous boosted primary series of inactivated COVID-19 vaccine compared with no second booster. Participants reported nucleic acid or antigen test results weekly until they tested positive or completed predesignated follow-up. After excluding participants infected <14 days after study entry, relative effectiveness among the 6576 participants was 61% in 18- to 59-year-olds and 38% in ≥60-year-olds and was sustained for 12 weeks.

A Kr*-Rb cold collision apparatus based on atom trap.

A cold collision between atoms and molecules (<1 K) is one of the hot research fields in atomic and molecular physics. At low temperatures, the number of partial waves participating in the collision process decreases dramatically, and quantum phenomena start to emerge. The reaction is often dominated by quantum tunneling, and pronounced resonances can exist on collision cross sections. Here, we report on an apparatus designed for studying cold collisions between metastable noble gas atoms and alkali atoms. Our apparatus features a combined Magneto-Optical-Trap (MOT) and velocity map imaging (VMI) system. The center of a Rb MOT is overlapped with the VMI system. Cold Kr* atoms are launched toward the Rb atoms to induce Kr* + Rb reactions. The collision energy between the two species can be varied from 100 mK to 20 K. With this setup, we are planning to explore the quantum phenomena in Kr* + Rb cold collisions, including the shape resonance and stereodynamics in the reaction.

Sacubitril/valsartan attenuates myocardial inflammation, hypertrophy, and fibrosis in rats with heart failure with preserved ejection fraction.

Heart failure with preserved ejection fraction (HFpEF) represents a multifaceted syndrome related to complex pathologic mechanisms. Sacubitril/valsartan (Sac/val) has demonstrated therapeutic efficacy in HFpEF treatment. However, additional research is required to elucidate its pharmacological mechanisms. Accordingly, this study aimed to explore the potential therapeutic effects of Sac/val in HFpEF rats and the underlying molecular mechanisms. In this study, rats with HFpEF were induced by subjecting spontaneously hypertensive rats to a diet rich in fats, salts, and sugars, along with administering streptozotocin. Subsequently, they were administered Sac/val at a daily dosage of 18 mg/kg. Finally, cardiac structure and function were assessed using echocardiography; Hematoxylin and eosin staining and Masson's trichrome staining were employed to evaluate the pathological changes; Quantitative real-time polymerase chain reaction and Western blot analysis were conducted to determine the expression of pertinent mRNA and proteins. Sac/val treatment attenuated left ventricular (LV) remodeling and diastolic dysfunction in HFpEF rats, possibly related to its anti-inflammatory, anti-hypertrophic, and anti-fibrotic efficacy. Mechanistically, Sac/val might inhibit inflammation by down-regulating cell adhesion molecule (intercellular adhesion molecule-1 (ICAM-1) and vascular endothelial cell adhesion molecule-1 (VCAM-1)) expression. Additionally, it blocked the phosphorylation of glycogen synthase kinase 3ß (GSK-3ß) to prevent cardiomyocyte hypertrophy. Furthermore, it effectively suppressed myocardial fibrosis by inhibiting the transforming growth factor-beta1 (TGF-ß1)/Smads pathway. Our findings suggest that Sac/val improved LV remodeling and diastolic dysfunction, potentially attributed to its anti-inflammatory, anti-hypertrophic, and anti-fibrotic effects. These results provide a sound theoretical rationale for the clinical application of Sac/val in patients with HFpEF.

Prognostic value of platelet distribution width to lymphocyte ratio in patients with hepatocellular carcinoma following hepatectomy.

BACKGROUND: Platelet distribution width (PDW), but not platelet count, was found to more comprehensively reflect platelet activity. The present study, thus, aimed to evaluate the prognostic value of PDW to lymphocyte ratio (PDWLR) in patients with hepatocellular carcinoma (HCC) following hepatectomy. METHODS: Patients following hepatectomy were analyzed retrospectively. The Kaplan-Meier survival curves and Cox regression model were used to determine the prognostic value of PDWLR. RESULTS: 241 patients were analyzed eventually, and stratified into low and high PDWLR groups (≤ 9.66 vs. > 9.66). Results of comparing the baseline characteristics showed that high PDWLR was significantly associated with cirrhosis, and intraoperative blood loss (all P < 0.05). In multivariate COX regression analysis, PDWLR was demonstrated as an independent risk factor for OS (HR: 1.549, P = 0.041) and RFS (HR: 1.655, P = 0.005). Moreover, PDWLR demonstrated a superior capacity for predicting prognosis compared to other indicators. CONCLUSION: Preoperative PDWLR has a potential value in predicting the prognosis of HCC patients following hepatectomy, which may help in clinical decision-making for individual treatment.

Daytime dysfunction may be associated with postoperative delirium in patients undergoing total hip/knee replacement: The PNDABLE study.

PURPOSE: Postoperative delirium (POD) is a usual complication after total hip/knee replacement, which may be affected by sleep characteristics. However, up to now, preoperative sleep characteristics have not been evaluated as risk factors of POD. The relationship between self-reported sleep characteristics and POD in patients has been investigated in this study. PATIENTS AND METHODS: We recruited 495 cognitively intact individuals in the final analysis from the Perioperative Neurocognitive Disorder and Biomarker Lifestyle study. Sleep characteristics were tested by the Pittsburgh Sleep Quality Index (PSQI). Mini-mental state examination was applied to assess preoperative mental status of patients. Postoperatively, we used confusion assessment method and memorial delirium assessment scale to evaluate the incidence of POD and POD severity, respectively. The cerebrospinal fluid (CSF) levels of T-tau, P-tau, Aß40, and Aß42 were detected by enzyme-linked immune-sorbent assay before the operation. Logistic regression, multiple linear regression, and mediation effects were performed to analyze the relationship between self-reported sleep characteristics and POD. RESULTS: POD was detected in 11.31% (56/495) of the patients, with logistic regression analysis showing that daytime dysfunction, P-tau, and T-tau were risk factors of POD, and Aß42 was a protective factor of POD. Multiple linear regression analysis confirmed that daytime dysfunction was positively correlated with P-tau in patients with POD. Meanwhile, compared to the patients with no postoperative delirium, the CSF levels of P- and T-tau were higher in patients with POD. Furthermore, mediation analysis showed that it was probable that daytime dysfunction mediated POD through P-tau (proportion: 12.90%) partially. CONCLUSION: Daytime dysfunction is a risk factor of POD preoperatively. To sum up, CSF P-tau protein might partially mediate the influence of daytime dysfunction on POD. CLINICAL TRIAL REGISTRATION: This study was registered at Chinese Clinical Trial Registry (ChiCTR2000033439).

Intracranial infection and sepsis in infants caused by Salmonella derby: A case report.

BACKGROUND: Salmonella derby (S. derby) is a Gram-negative diplococcus that is common in the digestive tract. Infected patients generally experience symptoms such as fever and diarrhea. Mild cases are mostly self-healing gastroenteritis, and severe cases can cause fatal typhoid fever. Clinical cases are more common in children. The most common form of S. derby infection is self-healing gastroenteritis, in which, fever lasts for about 2 d and diarrhea for < 7 d. S. derby can often cause bacterial conjunctivitis, pneumonia, endocarditis, peritonitis and urethritis. However, intracranial infections in infants caused by S. derby are rare in clinical practice and have not been reported before in China. CASE SUMMARY: A 4-mo-old female infant had recurrent fever for 2 wk, with a maximum body temperature of around 39.4°C. Treatment for infectious fever in a local hospital was ineffective, and she was admitted to our hospital. Before admission, there was one sudden convulsion, characterized by unclear consciousness, limb twitching, gaze in both eyes, and slight cyanosis on the face. Cerebrospinal fluid (CSF) culture was positive for Gram-negative bacilli, which conformed to S. derby. After treatment with meropenem and ceftriaxone antibiotics, the patient was discharged home in a clinically stable state after 4 wk of treatment. CONCLUSION: We reported a rare case of S. derby cultured in CSF. S. derby enters the CSF through the blood-brain barrier, causing purulent meningitis. If not treated timeously, it can lead to serious, life-threatening infection.

Naples Prognostic Score is an Independent Prognostic Factor in Patients Undergoing Hepatectomy for Hepatocellular Carcinoma.

Background: Nutritional and inflammatory status has been reported to be associated with the prognosis of hepatocellular carcinoma (HCC), but many studies did not include all biomarkers simultaneously. The present study aimed to determine the impact of Naples prognostic score (NPS) on the long-term survival in patients undergoing hepatectomy for HCC. Methods: Patients with HCC after curative resection were eligible. Then, all patients were stratified into three groups according to the NPS. Clinical features and survival outcomes were compared among the three groups. Independent prognostic factors were determined by COX analysis. The time dependent receiver operating characteristic (ROC) curves were used to compare prognostic performance with other immunonutrition scoring systems. Results: A total of 476 patients were enrolled eventually. Baseline characteristics showed that patients with higher NPS had a higher proportion of poor liver function and advanced tumor features. Accordingly, Kaplan-Meier survival curves showed that patients with higher NPS had a lower rate of overall survival (OS) and recurrence-free survival (RFS). Multivariable COX analysis demonstrated that NPS was an independent risk factor of OS (NPS group 2 vs 1: HR=1.958, 95% CI: 1.038-3.369, p = 0.038; NPS group 3 vs 1: HR=2.608, 95% CI: 1.358-5.008, p=0.004, respectively) and RFS (NPS group 2 vs 1: HR=2.014, 95% CI: 1.299-2-3.124, p=0.002; NPS group 3 vs 1: HR=2.002, 95% CI: 1.262-3.175, p=0.003, respectively). The time-dependent ROC curve showed that NPS was superior to other models in prognostic performance and discriminatory power for long-term survival (median AUC 0.675, 95% CI: 0.586-0.712, P < 0.05). Conclusion: The NPS is a simple tool strongly associated with long-term survival in patients undergoing curative hepatectomy for HCC.

Preoperative prediction model for microvascular invasion in HBV-related intrahepatic cholangiocarcinoma.

BACKGROUND AND AIMS: Preoperative prediction of microvascular invasion (MVI) using a noninvasive method remain unresolved, especially in HBV-related in intrahepatic cholangiocarcinoma (ICC). This study aimed to build and validate a preoperative prediction model for MVI in HBV-related ICC. METHODS: Patients with HBV-associated ICC undergoing curative surgical resection were identified. Univariate and multivariate logistic regression analyses were performed to determine the independent risk factors of MVI in the training cohort. Then, a prediction model was built by enrolling the independent risk factors. The predictive performance was validated by receiver operator characteristic curve (ROC) and calibration in the validation cohort. RESULTS: Consecutive 626 patients were identified and randomly divided into the training (418, 67%) and validation (208, 33%) cohorts. Multivariate analysis showed that TBIL, CA19-9, tumor size, tumor number, and preoperative image lymph node metastasis were independently associated with MVI. Then, a model was built by enrolling former fiver risk factors. In the validation cohort, the performance of this model showed good calibration. The area under the curve was 0.874 (95% CI: 0.765-0.894) and 0.729 (95%CI: 0.706-0.751) in the training and validation cohort, respectively. Decision curve analysis showed an obvious net benefit from the model. CONCLUSION: Based on clinical data, an easy model was built for the preoperative prediction of MVI, which can assist clinicians in surgical decision-making and adjuvant therapy.

Kinetics and Combustion Behavior of Atomized Zn-Mg Alloy Powder.

Using pyrolants instead of warhead charges can release red light and thick smoke for target practice to highlight the safety of the impact point and dud disposal. In order to find the ideal material, the combustion and kinetic properties of two Zn-Mg alloys at critical proportions were investigated. Thermogravimetry/differential scanning calorimetry (TG/DSC) experiments in pure oxygen were conducted with atomized Zn-Mg alloy powder in the ratio of 7:3 and the ratio of 8:2 with three particle diameters under different heating rates. The kinetic parameters of the six materials were obtained by ASTM E698 and Ozawa-Flynn-Wall (OFW) methods, indicating that the activation energy (Eα) of the 7:3 Zn-Mg alloy powder was lower than that of the 8:2 Zn-Mg alloy powder when the particle size distributions are similar. By the method of nonlinear multivariate regression, the oxidation reaction of Zn-Mg alloy powder was divided into two steps. The proportion of mass gain of the first-step reaction of 7:3 Zn-Mg alloy powder was 0.462-0.518, and the proportion of mass gain of the first-step reaction of 8:2 Zn-Mg alloy powder was 0.138-0.228. Reaction mechanism functions of the two-step reaction of Zn-Mg alloy oxidation were derived as f(α) = (1 - α)n(1 + kcat·α). The results of combustion experiments showed that the pyrolants composed of 7:3 alloy can burn stably to produce satisfactory smoke and light signals, while the pyrolants composed of 8:2 alloy cannot achieve this. The 7:3 Zn-Mg alloy powder is an ideal ingredient for pyrotechnic compositions.