Utilizing Single-Branched Stent in Combination With Fenestration or Chimney for Endovascular Repair of Aortic Arch Lesions With Aberrant Subclavian Artery.

OBJECTIVE: The study was to figure out the feasibility, efficacy, and safety of a single-branched stent graft, namely Castor, in combination with fenestration or chimney in the context of aortic arch lesions presenting with aberrant subclavian artery (ASA) and/or Kommerell's diverticulum (KD). METHODS: All consecutive patients with aortic arch lesions and ASA and/or KD receiving Castor from June 2018 to June 2023 were investigated. RESULTS: Incorporating 18 patients, the study encompassed 11 cases with KD, 3 cases with dysphagia; 2 cases of right-sided aortic arch with left-sided aberrant left subclavian artery (ALSA), and 16 cases of left-sided aortic arch with right-sided aberrant right subclavian artery (ARSA). The mean operation time was 132±23 minutes. The mean measured proximal aortic diameter was 30.9±1.6 mm, and proximal diameter of Castor stent was 34 (32, 34.5) mm, with oversize of 9.1±1.6%; the mean measured branch diameter was 8.8±0.97 mm, and branch diameter of Castor stent was 10 (8, 10) mm, with oversize of 0.86±0.57 mm. Technical success rate was 100%, and no in-hospital mortality, no stroke, and no endoleak were identified. One (5.6%) case with spinal cord ischemia and one (5.6%) case with poor healing of operative site were identified. During the follow-up period, no aortic-related death or secondary intervention was recorded. The maximal aortic diameter was significantly reduced at the sixth postoperative month (padj=0.031); KD diameter was significantly reduced at the third (padj=0.001) and sixth (padj<0.001) postoperative month. CONCLUSION: Totally endovascular repair of aortic arch lesions with ASA and KD via Castor stent in combination with fenestration or chimney is feasible, effective, and safe, which can achieve an encouraging medium-term outcome and provide excellent remodeling at the lesions. CLINICAL IMPACT: Single branched stent in combination with fenestration or chimney achieved a sufficient proximal landing zone and provided an encouraging medium-term outcome in this retrospective review of 18 patients receiving endovascular treatment of pathological aortic arch with aberrant subclavian artery and/or Kommerell's diverticulum. The authors suggest this time-saving and efficient technique to establish systematic experience for the treatment in this kind of patients.

RNase H-Driven crRNA Switch Circuits for Rapid and Sensitive Detection of Various Analytical Targets.

The clustered regularly interspaced short palindromic repeats (CRISPR/Cas12a) system has exhibited great promise in the rapid and sensitive molecular diagnostics for its trans-cleavage property. However, most CRISPR/Cas system-based detection methods are designed for nucleic acids and require target preamplification to improve sensitivity and detection limits. Here, we propose a generic crRNA switch circuit-regulated CRISPR/Cas sensor for the sensitive detection of various targets. The crRNA switch is engineered and designed in a blocked state but can be activated in the presence of triggers, which are target-induced association DNA to initiate the trans-cleavage activity of Cas12a for signal reporting. Additionally, RNase H is introduced to specifically hydrolyze RNA duplexed with the DNA trigger, resulting in the regeneration of the trigger to activate more crRNA switches. Such a combination provides a generic and sensitive strategy for the effective sensing of the p53 sequence, thrombin, and adenosine triphosphate. The design is incorporated with nucleic acid nanotechnology and extensively broadens the application scope of the CRISPR technology in biosensing.

A new model (Alfalfa-Warfarin-GIB) for predicting the risk of major gastrointestinal bleeding in warfarin patients.

BACKGROUND: This study aimed to analyze the factors influencing warfarin-related major gastrointestinal bleeding (GIB) and to develop a score that would provide a reference for assessing the risk of major GIB associated with warfarin treatment. METHODS: This was a retrospective analysis of clinical and follow-up data from warfarin-treated patients. Scores were analyzed using logistic regression. The area under the subject working characteristic curve (AUC), sensitivity, specificity, and Hosmer-Lemeshow test were used to evaluate the scoring performance. RESULTS: A total of 1591 patients who met the requirements for warfarin use were included in this study, and 46 developed major GIB. After univariate analysis as well as multivariate logistic regression analysis, nine factors were found to be associated with increased risk of major GIB, namely age ≥ 65 years, history of peptic ulcer, history of major bleeding, abnormal liver function, abnormal renal function, cancer, anemia, labile international normalized ratio, and combination of antiplatelet agents/non-steroidal anti-inflammatory drugs. The Alfalfa-Warfarin-GIB score was constructed using these nine factors. The AUC and Bootstrap method-corrected AUC of the Alfalfa-Warfarin-GIB score were 0.916 (95% CI: 0.862-0.970, P < 0.001) and 0.919 (95% CI: 0.860-0.967, P < 0.001), respectively, which were higher than those of the HAS-BLED score (AUC = 0.868, 95% CI: 0.812-0.924, P < 0.001). CONCLUSION: Based on nine risk factors, the Alfalfa-Warfarin-GIB score was constructed to predict the risk of warfarin-related major GIB. The newly developed Alfalfa-Warfarin-GIB score has a better predictive value than the HAS-BLED score and may be an effective tool to help reduce the occurrence of major GIB in patients on warfarin.

Conductively coupled flexible silicon electronic systems for chronic neural electrophysiology.

Materials and structures that enable long-term, intimate coupling of flexible electronic devices to biological systems are critically important to the development of advanced biomedical implants for biological research and for clinical medicine. By comparison with simple interfaces based on arrays of passive electrodes, the active electronics in such systems provide powerful and sometimes essential levels of functionality; they also demand long-lived, perfect biofluid barriers to prevent corrosive degradation of the active materials and electrical damage to the adjacent tissues. Recent reports describe strategies that enable relevant capabilities in flexible electronic systems, but only for capacitively coupled interfaces. Here, we introduce schemes that exploit patterns of highly doped silicon nanomembranes chemically bonded to thin, thermally grown layers of SiO2 as leakage-free, chronically stable, conductively coupled interfaces. The results can naturally support high-performance, flexible silicon electronic systems capable of amplified sensing and active matrix multiplexing in biopotential recording and in stimulation via Faradaic charge injection. Systematic in vitro studies highlight key considerations in the materials science and the electrical designs for high-fidelity, chronic operation. The results provide a versatile route to biointegrated forms of flexible electronics that can incorporate the most advanced silicon device technologies with broad applications in electrical interfaces to the brain and to other organ systems.

Learning Curve from 100 Cases of Totally Thoracoscopic Mitral Valve Replacement.

BACKGROUND: To investigate and analyze the learning curve of totally thoracoscopic mitral valve replacement and provide a quantitative reference for cardiac surgeons to carry out the operation step by step. METHODS: The clinical data were retrospectively analyzed of 100 consecutive patients with totally thoracoscopic mitral valve replacement successively performed by the same surgeon in a single center from May 2019 to June 2020. The learning curve was divided into 2 stages by using cumulative sum analysis, and relevant surgical parameters and perioperative indicators were analyzed. RESULTS: The first stage of the learning curve is the skill acquisition stage, which includes 1 to 40 surgical procedures. The second stage is the proficiency stage, involving 41 to 100 operations. Among the surgical parameters of the patients in the 2 stages, detectable improvements were observed in operative time, cardiopulmonary bypass time, cross-clamp time, and intraoperative injury. After surgery, the amount of drainage, length of hospital stay, blood creatinine levels, and oxygenation index 24 h after surgery were also significantly different between the 2 groups (all P < .05). The age and sex distributions of the patients were balanced, and there was no statistically significant difference in terms of conversion to median sternotomy between the 2 stages (P > .05). CONCLUSIONS: Cumulative sum analysis was used to accurately analyze the learning curve of totally thoracoscopic mitral valve replacement, indicating that 40 cases are needed to master the technique.

Ultrathin, transferred layers of thermally grown silicon dioxide as biofluid barriers for biointegrated flexible electronic systems.

Materials that can serve as long-lived barriers to biofluids are essential to the development of any type of chronic electronic implant. Devices such as cardiac pacemakers and cochlear implants use bulk metal or ceramic packages as hermetic enclosures for the electronics. Emerging classes of flexible, biointegrated electronic systems demand similar levels of isolation from biofluids but with thin, compliant films that can simultaneously serve as biointerfaces for sensing and/or actuation while in contact with the soft, curved, and moving surfaces of target organs. This paper introduces a solution to this materials challenge that combines (i) ultrathin, pristine layers of silicon dioxide (SiO2) thermally grown on device-grade silicon wafers, and (ii) processing schemes that allow integration of these materials onto flexible electronic platforms. Accelerated lifetime tests suggest robust barrier characteristics on timescales that approach 70 y, in layers that are sufficiently thin (less than 1 µm) to avoid significant compromises in mechanical flexibility or in electrical interface fidelity. Detailed studies of temperature- and thickness-dependent electrical and physical properties reveal the key characteristics. Molecular simulations highlight essential aspects of the chemistry that governs interactions between the SiO2 and surrounding water. Examples of use with passive and active components in high-performance flexible electronic devices suggest broad utility in advanced chronic implants.

Diagnostic Classification Models for Testlets: Methods and Theory.

Diagnostic classification models (DCMs) have seen wide applications in educational and psychological measurement, especially in formative assessment. DCMs in the presence of testlets have been studied in recent literature. A key ingredient in the statistical modeling and analysis of testlet-based DCMs is the superposition of two latent structures, the attribute profile and the testlet effect. This paper extends the standard testlet DINA (T-DINA) model to accommodate the potential correlation between the two latent structures. Model identifiability is studied and a set of sufficient conditions are proposed. As a byproduct, the identifiability of the standard T-DINA is also established. The proposed model is applied to a dataset from the 2015 Programme for International Student Assessment. Comparisons are made with DINA and T-DINA, showing that there is substantial improvement in terms of the goodness of fit. Simulations are conducted to assess the performance of the new method under various settings.

An Off-Pump Repair Technique for Postinfarction Apical Left Ventricular Aneurysm.

PURPOSE: The conventional surgical treatment for postinfarction left ventricular aneurysm (LVA) is open-heart repair with cardiopulmonary bypass. However, the risk of the open-heart surgery under cardiopulmonary bypass may result in an unacceptable risk for many patients with multiple comorbidities. Here, we reported a new off-pump repair technique for postinfarction apical LVA. METHODS: A new off-pump repair technique, circular banding and occlusion technique, was applied to repair the postinfarction apical LVA in 12 patients. Clinical data of all those 12 patients were retrospectively reviewed. Patients were followed up prospectively by direct interviews and echocardiographic examination. RESULTS: The new repair technique was successfully performed in all these 12 patients. Acute reduction of the LVA mouth diameter, the left ventricular (LV) end-diastolic volume and end-systolic volume, and an increase in the LV ejection fraction (EF) were immediately obtained after the repair. Patients had an uneventful postoperative course. They were in New York Heart Association class 1-2, and the LV volume and EF detected by echocardiography remained unchanged during an average 28.4 ± 9.9 months (range 13 to 45 months) follow-up. CONCLUSIONS: Circular banding and occlusion is a simple, safe, and effective off-pump repair technique for postinfarction apical LVA. It can allow effective LV remodeling and improve heart function.

ENPP2 alleviates hypoxia/reoxygenation injury and ferroptosis by regulating oxidative stress and mitochondrial function in human cardiac microvascular endothelial cells.

This study aimed to elucidate the molecular mechanisms of hypoxia/reoxygenation (H/R) injury in human cardiac microvascular endothelial cells (HCMECs) by regulating ferroptosis. H/R model was established with HCMECs and before the reperfusion, ferroptosis inhibitor ferrostatin-1 or ferroptosis inducer erastin was all administered. Wound-healing assay was performed to detect the migration ability of cells in each group, and the angiogenesis ability was determined by tube formation assay. The level of reactive oxygen species (ROS) was detected by flow cytometry. Transmission electron microscopy (TEM) was used to observe the state of mitochondria. The expressions of related proteins in HCMECs were assessed by Western blot. From the results, H/R injury could inhibit the migration and angiogenesis, induce the ROS production, and cause the mitochondrial damage of HCMECs. Ferroptosis activator erastin could aggravate H/R injury in HCMECs, while the ferroptosis inhibitor ferrostatin-1 could reverse the effects of H/R on HCMECs. Western blot results showed that H/R or/and erastin treatment could significantly induce ACSL4, HGF, VEGF, p-ERK, and uPA protein expression and inhibit GPX4 expression. The addition of ferrostatin-1 resulted in the opposite trend of the proteins expression above to erastin treatment. What is more, overexpression of ENPP2 markedly suppressed the damaging effect of H/R on HCMECs and reversed the effects of H/R or erastin treatment on the expression of related proteins. These results demonstrated a great therapeutic efficacy of ENPP2 overexpression in preventing the development of H/R injury through inhibiting oxidative stress and ferroptosis.

Application of a warfarin dosing calculator to guide individualized dosing versus empirical adjustment after fixed dosing: a pilot study.

Background: Warfarin has a narrow therapeutic window and individual variation, and patients require regular follow-up and monitoring of the International Normalized Ratio (INR) for dose adjustment. The calculation method of Warfarin Dosing Calculator (WDC) software is based on the European and American populations, and its accuracy in the Chinese population is yet to be verified. Objective: This study was to evaluate the feasibility of applying Warfarin Dosing Calculator software intervention in a real-world clinical research setting in China. Methods: The pilot study divided the included patients after valve replacement into an experimental group and a control group, with 38 cases in each group. In the control group, the initial dose was fixed at 2.5 mg/d and the dose was adjusted empirically during the study period; in the experimental group, the Warfarin Dosing Calculator software was applied to guide the dosing, and patients in both groups were followed up for 3 months. Analysis of the incidence anticoagulation outcomes and excessive anticoagulation events in both groups. Kaplan-Meier survival curves were used to analyze the correlation between different dosing regimens and first International Normalized Ratio attainment, and Logrank tests were performed. Results: The mean time required for first International Normalized Ratio compliance in the experimental group was 4.38 days less than in the control group, and the mean number of tests was 1.43 less (p < 05). Time in therapeutic range (TTR) was significantly higher in the experimental group than in the control group (p < 05). Kaplan-Meier survival curve analysis showed that the first International Normalized Ratio attainment rate was significantly higher in the experimental group than in the control group (p = 01). No major bleeding events occurred in either group, but other excessive anticoagulation events (INR>3.5 and minor bleeding) were significantly reduced in the experimental group compared with the control group (p < 05). Conclusion: Application of Warfarin Dosing Calculator software to guide individualized warfarin dosing may be better than a fixed dose of 2.5 mg/d. It may be shorten the time to first International Normalized Ratio attainment, and the attainment rate in the same time, and can better improve the mean Time in therapeutic range level value and reduce excessive anticoagulation events, which improves the safety of warfarin anticoagulation therapy in clinical practice. Clinical Trial Registration: https://www.chictr.org.cn/showproj.html?proj=52793, ChiCTR2000032393.

Triple-Branched Stent Graft Implantation for Acute Non-A-non-B Aortic Dissection.

BACKGROUND: The optimal treatment for acute non-A-non-B aortic dissection remains controversial. Triple-branched stent graft (TBSG) implantation has been used to treat acute type A aortic dissection. This study aimed to evaluate the safety and efficacy of TBSG as a treatment for acute non-A-non-B aortic dissection. METHODS: Fifty patients with non-A-non-B dissection received TBSG implantation in our center between January 2014 and December 2019. Early mortality, morbidity, and dissected aorta remodeling during follow-up were calculated. RESULTS: There were no deaths in-hospital or within 30 days. Postoperative complications included pneumonia (n = 12), acute kidney injury (n = 6; preoperative renal malperfusion, n = 4), transient cerebral injury (n = 6; preoperative cerebral malperfusion, n = 4), pleural effusion (n = 4), and pericardial effusion (n = 2). During follow-up, 1 patient experienced a stroke, and 2 patients required secondary interventional therapy for residual dissection below the level of the TBSG. All implanted TBSGs had good positioning, and all sidearm stent graft grafts were fully patent. No retrograde aortic dissection or type I endoleak was detected. CONCLUSIONS: TBSG implantation for acute non-A-non-B aortic dissection had a low incidence of mortality and morbidity, featuring good remodeling of the dissected aortic wall during follow-up. The early outcomes of this technique were satisfactory.

A new procedure for elimination of atrial fibrillation associated with mitral valve disease: a proof-of-concept study.

BACKGROUND: Left atrial enlargement and fibrosis have been linked to the pathogenesis of atrial fibrillation (AF). The authors aimed to introduce a novel concept and develop a new procedure for AF treatment based on these characteristics. METHODS: The study included three stages. The first stage was a descriptive study to clarify the characteristics of the left atrial enlargement and fibrosis' distribution in patients with mitral valve disease and long-standing persistent AF. Based on these characteristics, the authors introduced a novel concept for AF treatment, and then translated it into a new procedure. The second stage was a proof-of-concept study with this new procedure. The third stage was a comparative effectiveness research to compare the clinical outcomes between patients with this new procedure and those who received Cox-Maze IV treatment. RESULTS: Based on the nonuniform fashion of left atrial enlargement and fibrosis' distribution, the authors introduced a novel concept: reconstructing a left atrium with appropriate geometry and uniform fibrosis' distribution for proper cardiac conduction, and translated it into a new procedure: left atrial geometric volume reduction combined with left appendage base closure. As compared to the Cox-Maze IV procedure, the new procedure spent significantly shorter total surgery time, cardiopulmonary bypass time, and aortic cross-clamp time ( P <0.001). Besides, the new procedure was related to a shorter ICU stay period (odd ratio (OR)=0.45, 95% CI=0.26-0.78), lower costs (OR=0.15, 95% CI=0.08-0.29), and a higher rate of A wave of transmitral and transtricuspid flow reappearance (OR=1.76, 95% CI=1.02-3.04). CONCLUSIONS: The new procedure is safe and effective for eliminating AF associated with mitral valve disease.

Impact of minimally invasive mitral valve surgery on sexual dysfunction in male patients.

BACKGROUND: Sexual dysfunction after cardiac surgery can seriously affect patients' quality of life, but the impact of cardiac surgery on sexual function has long been neglected. Compared with conventional cardiac surgery, minimally invasive cardiac surgery has the advantages of aesthetic appearance and no disruption of the sternal structure, which can greatly improve the patient's quality of life. However, studies focusing on the effects of minimally invasive mitral valve surgery (MIMVS) on sexual function have not been reported. The objective of this research was to investigate the effects of totally endoscopic mitral valve surgery on health-related quality of life and sexual function in male patients and to provide possible recommendations. METHODS: Patients who underwent median sternotomy or totally endoscopic mitral valve surgery at our institution from January 2019 to December 2020 were selected using an electronic medical record system. Data were collected by questionnaires, including the MOS 36-item short-form health survey and the International Erectile Function Questionnaire. RESULTS: There were 156 male patients who participated in our study. Of these, 112 patients completed all questionnaires. Forty-five patients (40.18%) developed postoperative sexual dysfunction, including 15 patients (29.41%) in the MIMVS group and 30 patients (49.18%) in the conventional MVS group, indicating that the incidence of sexual dysfunction could be reduced by MIMVS and that the MIMVS group scored better on the International Erectile Function Questionnaire (P < 0.05). On the evaluation of health-related quality of life, the MIMVS group scored better than the MVS group on the mental health and bodily pain subscales of the MOS 36-item short-form health survey. In addition, our study showed that postoperative sexual dysfunction was associated with physical functioning and mental health. CONCLUSIONS: In our study, totally endoscopic mitral valve surgery had less adverse effects on sexual function in male patients than conventional mitral valve surgery. In terms of health-related quality of life, totally endoscopic mitral valve surgery was superior to conventional surgery. Patients who opt for totally endoscopic mitral valve surgery may have a more satisfying and healthier sexual life than those who undergo conventional mitral valve surgery.

Extensive repair of acute type A aortic dissection through a partial upper sternotomy and using complete stent-graft replacement of the arch.

BACKGROUND: Partial upper sternotomy (mini-ER) can be used in some adult cardiac surgeries but is seldom performed in the treatment of acute type A aortic dissection (AAAD). This study aimed to assess the feasibility and short-term outcomes of complete stent-graft replacement of the arch with triple-branched stent graft for AAAD through a mini-ER. METHODS: From 2015 to 2018, 254 patients with AAAD underwent complete stent-graft replacement of the arch with a triple-branched stent graft. Replacement was performed with conventional full sternotomy (con-ER) in 142 patients and with mini-ER in the other 112 patients. Using propensity score matching, the clinical data were compared between 100 patients in the mini-ER group and 100 patients in the con-ER group. RESULTS: After propensity score matching, there were no significant between-group differences in aortic cross-clamp time, cardiopulmonary bypass time, or total operative time. The amount of mediastinal drainage and number of red blood cell units were significantly lower in the mini-ER group compared with the con-ER group (P < .001). The intubation time was significantly shorter in the mini-ER group (P < .001). The treatment costs were also lower in the mini-ER group (P < .001). There were no significant between-group differences in 30-day mortality (9% vs 8%; P > .99) or postoperative complications. CONCLUSIONS: This study shows that extensive repair of AAAD through a mini-ER is feasible. It was superior to con-ER in terms of blood loss, postoperative ventilation time, and treatment costs.

Transthoracic Device Closure, Transcatheter Device Closure, and Surgical Repair via Right Submammary Thoracotomy for Restrictive Ventricular Septal Defect, a Respective Comparative Study.

BACKGROUND: Few comparative studies have focused on the advantages and disadvantages of transthoracic device closure, transcatheter device closure, and surgical repair via right submammary thoracotomy for restrictive ventricular septal defect (VSD). In this article, we compared the safety, efficacy, and clinical effects of these three treatments. Methods: The clinical data of 192 pediatric patients with a restrictive VSD in our hospital from January 2017 to May 2018 were retrospectively collected and analyzed. According to the different treatments, the patients were divided into three groups (the surgical and device groups). Results: There was no significant difference in the demographic characteristics, VSD size, mean pulmonary artery pressure, or cardiothoracic ratio. In addition, there were significant differences in the duration of mechanical ventilation, operation, hospitalization, and ICU stay between the two device groups and the surgical group, but there were no significant differences between the two device groups. Conclusions: Transthoracic device closure, transcatheter device closure, and surgical repair via right submammary thoracotomy for restrictive VSD repair are all safe and feasible. These three treatments have their own disadvantages and advantages and should be selected according to individual patients.

Novel Approach for Repair of a Left Atrial Esophageal Fistula After Radiofrequency Ablation.

Herein we described a novel repair approach for a left atrial esophageal fistula. Complete mediastinal debridement and simultaneous primary repairs of the left atrial posterior wall and the esophagus were completed under a median sternotomy, central cardiopulmonary bypass, left atrial circular incision around four pulmonary veins, inflamed left atrial posterior wall removal, and posterior pericardial opening.

Patch Neointima Technique in Acute Type A Aortic Dissection: Midterm Results of 147 Cases.

BACKGROUND: The patch neointima technique is a modified valve-sparing aortic root repair surgery for acute type A aortic dissection and the short-term outcomes are satisfactory. The midterm outcomes have not been reported. METHODS: From January 2009 to December 2012, 147 patients underwent valve-sparing aortic root repair with the patch neointima technique for type A aortic dissection in our center. The midterm outcomes of the patients were evaluated by echocardiography and aortic computed tomography angiography. RESULTS: Of 147 patients, 32 patients (21.8%) underwent proximal arch repair, and 115 patients (78.2%) underwent proximal arch repair combined with triple-branched stent graft implantation. The perioperative mortality was 5.4%. Preoperative aortic insufficiency (AI) was observed in 94 patients (63.9%); 131 patients (89.1%) left the operating room with 0 AI; the remaining 16 patients (10.9%) had trace or less than 1+ AI. A total of 128 patients (87.1%) completed 7-year follow-up. The mean follow-up time was 5.7 ± 1.2 years. As many as 82% of patients (105) were 0 AI and 15.6% of patients (20) were 0.5+ trace or less than 1+ AI. No reoperation was performed for the aortic root. The diameters of sinotubular junction and sinus were reduced to the normal range (28.3 ± 4.2 mm and 30.5 ± 3.6 mm, respectively) and remained stable (28.9 ± 5.6 mm, P = .300, and 30.8 ± 4.2 mm, P = .540, respectively) during 7 years of follow-up. CONCLUSIONS: Valve-sparing aortic root repair with patch neointima technique was associated with stable function of the aortic valves and no expansion of the aortic root in the midterm.

Latent Theme Dictionary Model for Finding Co-occurrent Patterns in Process Data.

Process data, which are temporally ordered sequences of categorical observations, are of recent interest due to its increasing abundance and the desire to extract useful information. A process is a collection of time-stamped events of different types, recording how an individual behaves in a given time period. The process data are too complex in terms of size and irregularity for the classical psychometric models to be directly applicable and, consequently, new ways for modeling and analysis are desired. We introduce herein a latent theme dictionary model for processes that identifies co-occurrent event patterns and individuals with similar behavioral patterns. Theoretical properties are established under certain regularity conditions for the likelihood-based estimation and inference. A nonparametric Bayes algorithm using the Markov Chain Monte Carlo method is proposed for computation. Simulation studies show that the proposed approach performs well in a range of situations. The proposed method is applied to an item in the 2012 Programme for International Student Assessment with interpretable findings.

A latent topic model with Markov transition for process data.

We propose a latent topic model with a Markov transition for process data, which consists of time-stamped events recorded in a log file. Such data are becoming more widely available in computer-based educational assessment with complex problem-solving items. The proposed model can be viewed as an extension of the hierarchical Bayesian topic model with a hidden Markov structure to accommodate the underlying evolution of an examinee's latent state. Using topic transition probabilities along with response times enables us to capture examinees' learning trajectories, making clustering/classification more efficient. A forward-backward variational expectation-maximization (FB-VEM) algorithm is developed to tackle the challenging computational problem. Useful theoretical properties are established under certain asymptotic regimes. The proposed method is applied to a complex problem-solving item in the 2012 version of the Programme for International Student Assessment (PISA).

Efficacy and safety of corticosteroids prophylaxis in cardiac surgery: A protocol for systematic review and meta-analysis.

BACKGROUND: Although corticosteroid prophylaxis in adult cardiac surgery has been studied extensively for 40 years, its role remains controversial, and the optimal dose remains uncertain. The objective of this meta-analysis was to estimate the clinical benefits and risks of corticosteroid use in cardiopulmonary bypass. METHODS: We will search Pubmed, Web of Science, Embase, Clinical Trials, and Cochrane Central Register of Controlled Trials for relevant clinical trials published in any language before August 1, 2020. Randomized controlled trials (RCTs) of interest which meet inclusion criteria published or unpublished will be included. We will divide the included studies into child and adult groups for analysis. If sufficient data are available, the included trials will be divided into 4 subgroups: ≤20 mg/kg (low dose), 20-40 mg/kg (slightly high dose), 40-100 mg/kg (high dose), and >100 mg/kg (ultra high dose) based on the equivalent hydrocortisone dose. INPLASY registration number: INPLASY2020100044. RESULTS: The results of this study will be published in a peer-reviewed journal. CONCLUSION: This study will compare the efficacy of tprophylactic corticosteroids for adults and children undergoing cardiac surgery with CPB. Due to the nature of the disease and intervention methods, randomized controlled trials may be inadequate, and we will carefully consider inclusion in high-quality, non-randomized controlled trials, but this may result in high heterogeneity and affect the reliability of the results.