Clinical predictive value of the age, creatinine, and ejection fraction score in patients in acute type A aortic dissection after total arch replacement.

The age, creatinine, and ejection fraction (ACEF) score has been accepted as a predictor of poor outcome in elective operations. This study aimed to investigate the predictive value of ACEF score in acute type A aortic dissection (AAAD) patients after total arch replacement. A total of 227 AAAD patients from July 2021 and June 2022 were enrolled and divided into Tertiles 1 (ACEF ≤ 0.73), Tertiles 2 (0.73 < ACEF ≤ 0.95), and Tertiles 3 (ACEF > 0.95). Using inverse probability processing weighting (IPTW) to balance the baseline characteristics and compare the outcomes. Cox logistic regression was used to further evaluate the survival prediction ability of ACEF score. The in-hospital mortality was 9.8%. After IPTW, in the baseline characteristics reached an equilibrium, a higher ACEF score before operation still associated with higher in-hospital mortality. After 1 year follow-up, 184 patients (90.6%) survival. Multivariable analysis revealed that ACEF score (adjusted hazard ratio 1.68; 95% confidence interval 1.34-4.91; p = 0.036) and binary ACEF score (adjusted HR 2.26; 95% CI 1.82-6.20; p < 0.001) was independently associated with 1-year survival. In addition, net reclassification improvement (NRI) and integrated differentiation improvement (IDI) verified that the ACEF score and binary ACEF score is an accurate predictive tool in clinical settings. In conclusions, ACEF score could be considered as a useful tool to risk stratification in patients with AAAD before operation in daily clinical work.

The prognostic value of preoperative systemic inflammatory response index in predicting outcomes of acute type A aortic dissection patients underwent surgical treatment.

Background: The systemic inflammatory response index (SIRI) is a novel inflammatory-immune biological marker that has prognostic value in various cardiovascular diseases. This study aims to investigate the relationship between SIRI and short-term and long-term prognosis in patients with acute type A aortic dissection (AAAD) underwent surgical treatment. Methods: We conducted a retrospective analysis of patients with AAAD who underwent emergency surgical treatment at our center. Through multifactorial logistics regression analysis and cox proportional hazards regression analysis, we identified SIRI as an independent risk factor for major adverse events (MAEs) and long-term aorta-related adverse events (ARAEs) post-surgery. The optimal cutoff value of preoperative SIRI was determined using receiver operating characteristic (ROC) curve analysis, and patients were divided into low SIRI group and high SIRI group. The prognostic outcomes at different time points post-surgery for the two groups of patients were analyzed using Kaplan-Meier survival analysis, and the significance was determined by log-rank test. Results: A total of 691 AAAD patients were included in this study. Among them, 50 patients (7.2%) died within 30 days post-surgery, and 175 patients (25.3%) experienced MAEs. A total of 641 patients were followed up, with an average follow-up time of 33.5 ± 17.5 months, during which 113 patients (17.6%) experienced ARAEs. The results of multifactorial logistics regression analysis and cox proportional hazards regression analysis showed that SIRI was an independent risk factor for postoperative MAEs (OR=3.148, 95%CI[1.650-6.006], p<0.001) and ARAEs (HR=2.248, 95%CI[1.050-4.809], p<0.037). Kaplan-Meier analysis demonstrated that the MAEs-free survival in the high SIRI group was significantly lower than that in the low SIRI group, and a similar trend was observed in the ARAEs-free survival during follow-up (log-rank test, p<0.001). Conclusion: Preoperative SIRI is significantly associated with the short-term and long-term prognosis of AAAD patients underwent emergency open surgery, demonstrating its valuable prognostic value. Therefore, preoperative SIRI is a reliable biological marker that can serve as a valuable tool for preoperative risk stratification and decision management.

Surgical management of the aortic root in acute type A aortic dissection: A comparative analysis.

BACKGROUND: This study aimed to assess the early- and mid-term outcomes of aortic root repair and replacement, and to provide evidence to improve root management in acute type A aortic dissection (AAAD). METHODS: This study enrolled 455 patients who underwent AAAD root repair (n = 307) or replacement (n = 148) between January 2016 and December 2017. Inverse probability of treatment weighting (IPTW) method was used to control for treatment selection bias. The primary outcomes were in-hospital mortality, mid-term survival, and proximal aortic reintervention. RESULTS: The success rate of root repair was 99.7%. The in-hospital mortality in the conservative root repair (CRR) and aggressive root replacement (ARR) were 8.1% and 10.8%. The median follow-up time was 67.76 months (IQR, 67-72 months). After adjusting for baseline factors, there was no significant differences in mid-term survival (p = .750) or the proximal aortic reintervention rate (p = .550) between the two groups. According to Cox analysis, age, hypertension, severe aortic regurgitation, CPB time, and concomitant CABG were all factors associated with mid-term mortality. Regarding reintervention, multivariate analysis identified renal insufficiency, bicuspid aortic valve, root diameter ≥ 45 mm, and severe aortic regurgitation as risk factors, while CRR did not increase the risk of reintervention. The subgroup analysis revealed heterogeneity in the effects of surgical treatment across diverse populations based on a variety of risk factors. CONCLUSIONS: For patients with AAAD, both CRR and ARR are appropriate operations with promising early and mid-term outcomes. The effects of treatment show heterogeneity across diverse populations based on various risk factors.

A predictive model for postoperative adverse outcomes following surgical treatment of acute type A aortic dissection based on machine learning.

Acute type A aortic dissection (AAAD) has a high probability of postoperative adverse outcomes (PAO) after emergency surgery, so exploring the risk factors for PAO during hospitalization is key to reducing postoperative mortality and improving prognosis. An artificial intelligence approach was used to build a predictive model of PAO by clinical data-driven machine learning to predict the incidence of PAO after total arch repair for AAAD. This study included 380 patients with AAAD. The clinical features that are associated with PAO were selected using the LASSO regression analysis. Six different machine learning algorithms were tried for modeling, and the performance of each model was analyzed comprehensively using receiver operating characteristic curves, calibration curve, precision recall curve, and decision analysis curves. Explain the optimal model through Shapley Additive Explanation (SHAP) and perform an individualized risk assessment. After comprehensive analysis, the authors believe that the extreme gradient boosting (XGBoost) model is the optimal model, with better performance than other models. The authors successfully built a prediction model for PAO in AAAD patients based on the XGBoost algorithm and interpreted the model with the SHAP method, which helps to identify high-risk AAAD patients at an early stage and to adjust individual patient-related clinical treatment plans in a timely manner.

A Predictive Model for Prolonged Mechanical Ventilation After Triple-Branched Stent Graft for Acute Type A Aortic Dissection.

INTRODUCTION: The aim of this study is to develop a model for predicting the risk of prolonged mechanical ventilation (PMV) following surgical repair of acute type A aortic dissection (AAAD). METHODS: We retrospectively collected clinical data from 381 patients with AAAD who underwent emergency surgery. Clinical features variables for predicting postoperative PMV were selected through univariate analysis, least absolute shrinkage and selection operator regression analysis, and multivariate logistic regression analysis. A risk prediction model was established using a nomogram. The model's accuracy and reliability were evaluated using the area under the curve of the receiver operating characteristic curve and the calibration curve. Internal validation of the model was performed using bootstrap resampling. The clinical applicability of the model was assessed using decision curve analysis and clinical impact curve. RESULTS: Among the 381 patients, 199 patients (52.2%) experienced postoperative PMV. The predictive model exhibited good discriminative ability (area under the curve = 0.827, 95% confidence interval: 0.786-0.868, P < 0.05). The calibration curve confirmed that the predicted outcomes of the model closely approximated the ideal curve, indicating agreement between the predicted and actual results (with an average absolute error of 0.01 based on 1000 bootstrap resampling). The decision curve analysis curve demonstrated that the model has significant clinical value. CONCLUSIONS: The nomogram model established in this study can be used to predict the risk of postoperative PMV in patients with AAAD. It serves as a practical tool to assist clinicians in adjusting treatment strategies promptly and implementing targeted therapeutic measures.

Do obese patients with type A aortic dissection benefit from total arch repair through a partial upper sternotomy?

Background: Minimal research has been performed regarding total arch replacement through partial upper sternotomy in patients with acute type A aortic dissection who are obese, and the safety and feasibility of this procedure need to be further investigated. The present study investigated the potential clinical advantages of using a partial upper sternotomy versus a conventional full sternotomy for total arch replacement in patients who were obese. Methods: This was a retrospective study. From January 2017 to January 2020, a total of 65 acute type A aortic dissection patients who were obese underwent total arch replacement with triple-branched stent graft. Among them, 35 patients underwent traditional full sternotomy, and 30 patients underwent partial upper sternotomy. The perioperative clinical data and postoperative follow-up results of the two groups were collected, and the feasibility and clinical effect of partial upper sternotomy in total arch replacement were summarized. Results: The in-hospital mortality rates of the two groups were similar. The total operative time, cardiopulmonary bypass, aortic cross-clamp, cerebral perfusion, and deep hypothermic circulatory arrest times were also similar in both groups. The thoracic drainage and postoperative red blood cell transfusion volumes in the partial upper sternotomy group were significantly lower than those in the full sternotomy group. Mechanical ventilation time was shorter in the partial upper sternotomy group than that in the full sternotomy group. Additionally, the incidences of pulmonary infection, hypoxemia, and sternal diaphoresis were lower in the partial upper sternotomy group than those in the full sternotomy group. Conclusion: This study showed that total arch replacement surgery through a partial upper sternotomy in patients with acute type A aortic dissection who are obese is safe, effective, and superior to full sternotomy in terms of blood loss, postoperative blood transfusion, and respiratory complications.

Quality of life in pregnancy after percutaneous closure of atrial septal defect guided by transthoracic echocardiography.

PURPOSE: We evaluated quality of life (QoL) in pregnant women who underwent transthoracic echocardiography-guided percutaneous closure of atrial septal defect (ASD). METHODS: A total of 45 pregnant women underwent transthoracic echocardiography-guided percutaneous closure of ASD. We assessed QoL using the 36-Item Short Form Survey (SF-36) and compared results between pre- and post-procedure patients, as well as between those with ASD and healthy women in their second and third trimesters of pregnancy. RESULTS: All patients showed improved right ventricular function and were classified as Class I, post-procedure. Mean SF-36 scores of the post-procedure group were better on all sub-scales than those of the pre-procedure group (p < 0.05), with the exception of role-emotional and mental health. Mean SF-36 scores for the pre-procedure group were also lower on all sub-scales than those of healthy pregnant controls (p < 0.05), with the exception of role physical, role emotional, and mental health. There was no difference between the post-procedure group and healthy pregnant controls. In a subgroup analysis, scores were better in some dimensions (social functioning and role emotional) for post-procedure patients in the 31-40 years of age group and the group on their second or third pregnancies than those of the 20-30 years of age group and the group on their first pregnancies (p < 0.05). CONCLUSION: After closure of ASD, QoL in pregnant women was improved. In a subgroup analysis, the younger women and those on their first pregnancy performed more poorly in some dimensions (social functioning and role emotional); this suggested that these groups should receive more proactive intervention.

Limited data was available on the general quality of life (QoL) in pregnant women with atrial septal defect (ASD), even though the condition could produce anxiety over health of the pregnancy and fetus. The percutaneous closure procedure was available for ASD during pregnancy; however, pregnant women were often concerned that the required X-rays would harm the fetus. A safe and effective procedure, percutaneous closure of ASD guided by transthoracic echocardiography, was widely used for this condition. This study used the 36-Item Short Form Survey (SF-36) to assess QoL in pregnant women with ASD pre- and post-procedure and compared the results to those of healthy pregnant women at a similar stage of pregnancy. Post-procedure QoL in pregnant women with ASD was improved; however, the younger women and those on their first pregnancy performed more poorly in some dimensions (social functioning and role emotional). Our results suggested that these groups should receive more proactive intervention.

Mid-term outcomes of right subaxillary approach versus median sternotomy incision for ventricular septal defect with patent ductus arteriosus.

BACKGROUND: This study aimed to evaluate and compare two surgical approaches to repair ventricular septal defect (VSD) with patent ductus arteriosus (PDA) and to explore the patients' health-related quality of life (HRQoL). METHODS: We conducted a retrospective study of all patients who had surgical repair of VSD and PDA between 2013 and 2015 using the right subaxillary approach (group A) or the median sternotomy incision (group B). The outcomes of both techniques were compared. Paediatric QoL Inventory 4.0 scale was applied to assess patients' HRQoL in the 6th postoperative year. Multiple linear regression analysis was performed to explore factors associated with higher HRQoL scores. RESULTS: A total of 128 patients were included (group A, n = 70 and group B, n = 58). Patients in group A were older and heavier than patients in group B. In group B, the diameters of VSD and PDA were larger and the pulmonary artery pressures were higher than those in group A (p < 0.001). No mortality occurred on a mean follow-up of 8.3 ± 1.2 years. Patients in group A had higher HRQoL scores than those in group B in terms of emotional and social functioning dimensions. The right subaxillary approach (OR: 3.56; 95% CI 1.65-5.46), higher parents' education level (OR: 1.62; 95% CI 0.65-2.31), and better family economic status (OR: 1.48; 95% CI 0.79-2.45) were associated with higher HRQoL scores. CONCLUSIONS: Younger and smaller patients receiving median sternotomy incisions due to large defects and pulmonary hypertension had lower HRQoL scores. The right subaxillary approach, higher parents' education level, and better family economic status were associated with higher HRQoL scores.

Do obese patients benefit from isolated aortic valve replacement through a partial upper sternotomy?

OBJECTIVE: Controversial opinions exist for aortic valve replacement (AVR) through partial upper sternotomy in obese patients. Moreover, this study sought to investigate the potential clinical advantage of partial upper sternotomy aortic valve replacement (mini-AVR) over conventional full sternotomy aortic valve replacement (con-AVR) in obese patients. METHODS: This was a retrospective and observational study. From January 2015 to December 2020, a total of 184 obese [body mass index (BMI) ≥ 30 kg  m2] patients undergoing isolated primary AVR were included: 98 patients underwent conventional full sternotomy, and 86 patients underwent partial upper sternotomy. Propensity score (PS) matching was applied to eliminate the bassline imbalances in the mini-AVR and the con-AVR groups. RESULTS: After one-to-one propensity score matching, two groups of 60 patients were obtained. No in-hospital death occurred in the two groups. In addition, cardiopulmonary bypass time and total operative time were similar across the 2 groups, but the aortic cross-clamp time was significantly shorter in the con-AVR group (P = .0.022). The amount of mediastinal drainage at 48 h after surgery (P = 0.018) and postoperative blood transfusions (P = 0.014) were significantly lower in the mini-AVR group. There was no difference in ventilation time (P = .0.145), but a shorter intensive care unit stay time (P = 0.021) in the mini-AVR group. CONCLUSION: This study demonstrates that aortic valve replacement through a mini-AVR in obese patients is a safe and effective procedure. It outperformed con-AVR in terms of blood loss, blood product transfusion, and ICU stay.

Plasma interleukin-6 is a potential predictive biomarker for postoperative delirium among acute type a aortic dissection patients treated with open surgical repair.

OBJECTIVES: The relationship between inflammatory cytokines and postoperative delirium (POD) remains to be further investigated, especially in patients undergoing acute type A aortic dissection (AAD). Interleukin-6 (IL-6) is involved in the inflammatory process and has recently been identified as a biomarker of cerebral dysfunction. We explored the hypothesis that IL-6 was one of the critical causes of POD after surgical repair of AAD. METHODS: Plasma IL-6 was measured using electrochemiluminescence technology in patients preoperatively and 24 h, 48 h, and 72 h after surgical repair of acute type A aortic dissection. After the first three postoperative days, delirium was evaluated twice daily using the Confusion Assessment Method. ROC curves were used to evaluate the ability of IL-6 measurements to distinguish POD. RESULTS: The incidence of POD was 14.03% (31 of 221 patients). The patients in the POD group were significantly older than the patients in the non-POD group (56.48 ± 11.68 years vs 52.22 ± 10.50 years, P = 0.040). Plasma IL-6 concentrations were significantly higher in the POD group than in the non-POD group at three time points: preoperatively, after 24 h, and after 48 h. The AUC values corresponding to IL-6 preoperatively and 24 h after surgery were 0.73 and 0.72, respectively. CONCLUSIONS: Cerebral dysfunction after the surgical repair of AAD shows elevated stress levels and inflammatory responses. Plasma IL-6 is a potential biomarker to predict the onset of POD in acute type A aortic dissection patients following surgical repair.

Efficiency of Modified Triple-Branched Stent Graft in Type I Aortic Dissection: Two-Year Follow-up.

BACKGROUND: The efficacy of hemiarch replacement combined with a modified triple-branched stent graft in Debakey type I aortic dissection remains to be confirmed. METHODS: From January 2016 to December 2017, 167 patients with acute Debakey type I aortic dissection underwent hemiarch replacement combined with a modified triple-branched stent graft. The clinical and imaging data were retrospectively analyzed. The early composite endpoint was defined to comprise perioperative mortality, permanent neurologic deficits, and renal failure requiring hemodialysis at discharge. RESULTS: The overall 30-day mortality was 4.2% (7 of 167). The incidence of the composite endpoint was 11.4% (19 of 167). The risk factors for the composite endpoint were malperfusion syndrome (odds ratio 5.17; 95% confidence interval, 1.46 to 18.35; P = .011) and creatine greater than 1.5 mg/dL (odds ratio 5.44; 95% confidence interval, 2.27 to 13.06; P < .001). The overall survival was 94% at 1 year and 92.2% at 2 years during a median follow-up of 20.9 ± 9.6 months. Three patients required distal aorta reintervention. Complete thrombosis in the false lumen of the descending aorta at the level of the pulmonary bifurcation and at the level of the celiac trunk was observed in 98.8% and 10.8% of the patients, respectively. CONCLUSIONS: Hemiarch replacement combined with a modified triple-branched stent graft is a reliable technique for acute Debakey type I aortic dissection as indicated by 2 years of follow-up.

Combination of Microwave Ablation and Percutaneous Osteoplasty for Treatment of Painful Extraspinal Bone Metastasis.

PURPOSE: To evaluate the efficacy and safety of microwave (MW) ablation combined with percutaneous osteoplasty (POP) on painful extraspinal bone metastases. MATERIALS AND METHODS: In this retrospective study, 50 adult patients with 56 extraspinal bone metastasis lesions, who suffered from refractory moderate to severe pain, were treated with MW ablation and POP. Changes in quality of life were evaluated based on the Visual Analog Scale (VAS), daily morphine consumption, and the Oswestry Disability Index (ODI) before and immediately after the procedure and during follow-up times. RESULTS: Technical success was achieved in all patients. Mean preoperative VAS score and morphine dose were 7.0 ± 2.6 (range, 3-10) and 66.7 ± 33.2 mg (range, 10-120 mg), respectively. Mean postoperative VAS scores and daily morphine doses were as follows: 1 day, 3.5 ± 2.1 and 36.1 ± 25.8 mg (P < .05); 1 week, 1.5 ± 1.7 and 12.2 ± 14.8 mg (P < .001); 1 month, 0.9 ± 1.4 and 5.7 ± 10.0 mg (P < .001); and 3 months, 0.6 ± 1.2 and 4.7 ± 8.4 mg (P < .001). A significant decrease in the ODI score was also observed (P < .05). Periprocedural death was not observed. A pathologic fracture occurred in 1 (2%) patient with femoral metastasis, and local infection was observed in 2 (4%) patients. Minor cement leakage occurred in 4 (8%) patients with no symptomatic or intra-articular extravasation. No local tumor progression occurred in patients with imaging follow-up. CONCLUSIONS: MW ablation combined with POP is an effective and safe treatment for painful extraspinal bone metastases, which can significantly relieve pain and improve quality of life.

Transcriptional sequencing and analysis of major genes involved in the adventitious root formation of mango cotyledon segments.

MAIN CONCLUSION: A total of 74,745 unigenes were generated and 1975 DEGs were identified. Candidate genes that may be involved in the adventitious root formation of mango cotyledon segment were revealed. Adventitious root formation is a crucial step in plant vegetative propagation, but the molecular mechanism of adventitious root formation remains unclear. Adventitious roots formed only at the proximal cut surface (PCS) of mango cotyledon segments, whereas no roots were formed on the opposite, distal cut surface (DCS). To identify the transcript abundance changes linked to adventitious root development, RNA was isolated from PCS and DCS at 0, 4 and 7 days after culture, respectively. Illumina sequencing of libraries generated from these samples yielded 62.36 Gb high-quality reads that were assembled into 74,745 unigenes with an average sequence length of 807 base pairs, and 33,252 of the assembled unigenes at least had homologs in one of the public databases. Comparative analysis of these transcriptome databases revealed that between the different time points at PCS there were 1966 differentially expressed genes (DEGs), while there were only 51 DEGs for the PCS vs. DCS when time-matched samples were compared. Of these DEGs, 1636 were assigned to gene ontology (GO) classes, the majority of that was involved in cellular processes, metabolic processes and single-organism processes. Candidate genes that may be involved in the adventitious root formation of mango cotyledon segment are predicted to encode polar auxin transport carriers, auxin-regulated proteins, cell wall remodeling enzymes and ethylene-related proteins. In order to validate RNA-sequencing results, we further analyzed the expression profiles of 20 genes by quantitative real-time PCR. This study expands the transcriptome information for Mangifera indica and identifies candidate genes involved in adventitious root formation in cotyledon segments of mango.

(2R, 3S)-Pinobanksin-3-cinnamate ameliorates photoreceptor degeneration in Pde6rd10 mice.

As an inherited disorder caused by initial death of rod photoreceptors, retinitis pigmentosa is currently untreatable and usually leads to partial or complete blindness. (2R, 3S)-Pinobanksin-3-cinnamate (PC) is a new flavonone isolated from the seed of Alpinia galanga Willd, and has been reported to exert neuroprotective effects by upregulating endogenous antioxidant enzymes. In this study, the anti-oxidative and neuroprotective activity of PC against photoreceptor apoptosis in rd10 mouse model of retinitis pigmentosa was explored. PC showed to produce significant improvement in histology and function in rd10 mice through reducing oxidative stress. For the first time, the protective effects of PC were demonstrated against retina degeneration in rd10 mice and our study provides scientific rationale on using PC as the supplementary treatment to the outer retina diseases, including retinitis pigmentosa, in which oxidative stress is thought to contribute to disease progression.

Novel TRPM1 mutations in two Chinese families with early-onset high myopia, with or without complete congenital stationary night blindness.

AIM: To investigate the relationship between high myopia [with or without complete congenital stationary night blindness (CSNB1)] and TRPM1 and NYX. METHODS: Two unrelated families with early-onset high myopia (eoHM) and 96 normal controls were recruited. Sanger sequencing or clone sequencing were used for mutation screening. Further analyses of the available family members and the 96 normal controls were subsequently conducted to obtain additional evidence of the pathogenicity of these variants. The initial diagnosis of the probands was eoHM. We performed a further comprehensive examination of the available family members after mutations were detected in TRPM1 or NYX. RESULTS: Two novel compound heterozygous mutations in TRPM1 were detected in the recruited families. The proband in family A with eoHM carried a c.2594C>T missense mutation in exon 19 and a c.669+3_669+6delAAGT splicing mutation, which was co-segregated with CSNB1 in this family. A patient in family B with a compound heterozygous missense mutation (c.3262G>A and c.3250T>C) was detected. No mutations were found in NYX. These two identified compound heterozygous mutations were not found in the 96 normal controls. After further examination of the family members, the patients in family A could be diagnosed as eoHM with CSNB1. However due to the limited clinic data, the patient in family B cloud not clearly diagnosed as CSNB1. CONCLUSION: This study has expanded the mutation spectrum of TRPM1 for CSNB1 and additional studies are needed to elucidate the association between isolated high myopia and TRPM1 and NYX.

Molecular Cloning and Characterization of Four Genes Encoding Ethylene Receptors Associated with Pineapple (Ananas comosus L.) Flowering.

Exogenous ethylene, or ethephon, has been widely used to induce pineapple flowering, but the molecular mechanism behind ethephon induction is still unclear. In this study, we cloned four genes encoding ethylene receptors (designated AcERS1a, AcERS1b, AcETR2a, and AcETR2b). The 5' flanking sequences of these four genes were also cloned by self-formed adaptor PCR and SiteFinding-PCR, and a group of putative cis-acting elements was identified. Phylogenetic tree analysis indicated that AcERS1a, AcERS1b, AcETR2a, and AcETR2b belonged to the plant ERS1s and ETR2/EIN4-like groups. Quantitative real-time PCR showed that AcETR2a and AcETR2b (subfamily 2) were more sensitive to ethylene treatment compared with AcERS1a and AcERS1b (subfamily 1). The relative expression of AcERS1b, AcETR2a, and AcETR2b was significantly increased during the earlier period of pineapple inflorescence formation, especially at 1-9 days after ethylene treatment (DAET), whereas AcERS1a expression changed less than these three genes. In situ hybridization results showed that bract primordia (BP) and flower primordia (FP) appeared at 9 and 21 DAET, respectively, and flowers were formed at 37 DAET. AcERS1a, AcERS1b, AcETR2a, and AcETR2b were mainly expressed in the shoot apex at 1-4 DAET; thereafter, with the appearance of BP and FP, higher expression of these genes was found in these new structures. Finally, at 37 DAET, the expression of these genes was mainly focused in the flower but was also low in other structures. These findings indicate that these four ethylene receptor genes, especially AcERS1b, AcETR2a, and AcETR2b, play important roles during pineapple flowering induced by exogenous ethephon.

Phase transition and flow-rate behavior of merging granular flows.

Merging of granular flows is ubiquitous in industrial, mining, and geological processes. However, its behavior remains poorly understood. This paper studies the phase transition and flow-rate behavior of two granular flows merging into one channel. When the main channel is wider than the side channel, the system shows a remarkable two-sudden-drops phenomenon in the outflow rate when gradually increasing the main inflow. When gradually decreasing the main inflow, the system shows obvious hysteresis phenomenon. We study the flow-rate-drop phenomenon by measuring the area fraction and the mean velocity at the merging point. The phase diagram of the system is also presented to understand the occurrence of the phenomenon. We find that the dilute-to-dense transition occurs when the area fraction of particles at the joint point exceeds a critical value ϕ(c)=0.65±0.03.

Physico-chemical properties, antioxidant activity and mineral contents of pineapple genotypes grown in china.

The fruit physico-chemical properties, antioxidant activity and mineral contents of 26 pineapple [Ananas comosus (L.) Merr.] genotypes grown in China were measured. The results showed great quantitative differences in the composition of these pineapple genotypes. Sucrose was the dominant sugar in all 26 genotypes, while citric acid was the principal organic acid. Potassium, calcium and magnesium were the major mineral constituents. The ascorbic acid (AsA) content ranged from 5.08 to 33.57 mg/100 g fresh weight (FW), while the total phenolic (TP) content varied from 31.48 to 77.55 mg gallic acid equivalents (GAE)/100 g FW. The two parameters in the predominant cultivars Comte de Paris and Smooth Cayenne were relative low. However, MD-2 indicated the highest AsA and TP contents (33.57 mg/100 g and 77.55 mg GAE/100 g FM, respectively), and it also showed the strongest antioxidant capacity 22.85 and 17.30 µmol TE/g FW using DPPH and TEAC methods, respectively. The antioxidant capacity of pineapple was correlated with the contents of phenolics, flavonoids and AsA. The present study provided important information for the further application of those pineapple genotypes.

Traffic experiment reveals the nature of car-following.

As a typical self-driven many-particle system far from equilibrium, traffic flow exhibits diverse fascinating non-equilibrium phenomena, most of which are closely related to traffic flow stability and specifically the growth/dissipation pattern of disturbances. However, the traffic theories have been controversial due to a lack of precise traffic data. We have studied traffic flow from a new perspective by carrying out large-scale car-following experiment on an open road section, which overcomes the intrinsic deficiency of empirical observations. The experiment has shown clearly the nature of car-following, which runs against the traditional traffic flow theory. Simulations show that by removing the fundamental notion in the traditional car-following models and allowing the traffic state to span a two-dimensional region in velocity-spacing plane, the growth pattern of disturbances has changed qualitatively and becomes qualitatively or even quantitatively in consistent with that observed in the experiment.

Phase diagrams of the Katz-Lebowitz-Spohn process on lattices with a junction.

This paper studies the Katz-Lebowitz-Spohn (KLS) process on lattices with a junction, where particles move on parallel lattice branches that combine into a single lattice at the junction. It is shown that 11 kinds of phase diagrams could be observed, depending on the two parameters ε and δ in the KLS process. We have investigated the phase diagrams as well as bulk density analytically based on flow rate conservation and the extremal current principle. Extensive Monte Carlo computer simulations are performed, and it is found that they are in excellent agreement with theoretical prediction.