Success Failure Research Articles

Progressive Collapse of Flat Slab Buildings

Progressive collapse occurs when a local failure triggers successive failures leading to total collapse of the structure. In this project, progressive collapse analysis has been done using a finite element linear static and a non linear static analysis on a 6 storey flat slab building. Though there are dynamic methods also for the analysis but static method has been used owing to its practicality and simplicity in engineering world. Dynamic method is more complicated and involves a number of iteration before it can give any close to accurate result, hence is not in much demand nowadays. The results for the linear static analysis have been compiled in the form of demand capacity ratio at critical section and results for that of the non-linear static analysis have been compiled in the form of support rotation at joints. In both the case the building is not susceptible to progressive collapse both when the central column is removed and the corner column is removed.

89 GUIDE EXTENSION CATHETER: INDICATION, USE AND RESULTS IN A LARGE SERIES OF COMPLEX PERCUTANEOUS CORONARY INTERVENTIONS

Abstract Aims The guide extension catheter (GEC) is a helpful tool to increase catheter support when facing complex percutaneous coronary intervention (PCI) in unfavorable coronary anatomies. The aim of this study was to describe indication, efficacy, and safety of the GEC in a high-volume center. Methods and results From 2014 to 2021, we retrospectively identified and analyzed 351 interventional cases in which GEC was used to complete the procedure. The endpoints of the study were PCI success, procedural success and device failure. GEC use increased over the years and was more frequently used by radial approach (92.1%) in elective setting (90.6%) and using the 6F size (95.3%). The GEC was mostly implemented as bail-out strategy (75.9%) with the aim to improve back-up (89.6%), less frequently to optimize catheter alignment or obtain selective coronary cannulation (10.4%). Intracoronary advancement was performed using the guidewire in 1.3% of cases, after positioning of a second “buddy” wire in 23.2%, with support of a deflated balloon at the distal tip in 12.2%, or with anchoring technique in 63.3%. Mean coronary deep intubation depth was 38.8±23.9mm. Vessel and lesion characteristics are reported in Table I. Overall, PCI success rate was 92.5%, while procedural success (PCI success without in hospital adverse event) was 88.6%. GEC was successfully used in 92.7% of patients with no device-dependent severe adverse events; in particular, failures were related to inability to cross the target lesion in 4.5% or to device–related complication in 2.85% of cases. Conclusions This large real-world registry on GEC use in complex PCI confirms the GEC as a valid and safe tool to increase backup support and overcome the limits of conventional technique during complex PCI.

Estimating the Occurrence Rate for Alpha-Series Process in Rayleigh Distribution

The geometric process is sometimes appropriate for reliability and scheduling problems. Some previous studies suggested a possible alternative process that is alpha-series as to the geometric process when it decreases with time, as the decreasing geometric process shows that the expected number of events at an arbitrary time does not exist. In contrast, the expected number of events of the alpha-series process (ASP) exists at an arbitrary time under some conditions. In this paper, we assumed that the first arrival followed the Rayleigh distribution (RD). The modified moment estimator was proposed to estimate the alpha-series process parameters in the Rayleigh distribution and compare it with the maximum likelihood estimators. A simulation was conducted to compare the two estimators. The real-data application of intervals between successive failures of the Mosul Dam power station in Nineveh governorate in Iraq is provided to illustrate the results. When the initial occurrence time distribution is indicated to be RD, an estimate of the occurrence rate of an ASP is investigated in this study. Estimators are generated using modified moment (MM), and maximum likelihood (ML) approaches. According to the simulation study's findings, the MM estimator outperforms the ML estimator. In all cases, ASP with RD provides better data than the renewal process (RP) in real data sets. A test statistic has been devised to determine if the data conforms to an ASP.

Influence of the three different types of standby components on the performance of a k–out–of–n:F system in the dynamic stress–strength model

We consider the effect of adding three different types of standby components to a k–out–of–n:F system based on the dynamic stress–strength model. For this purpose, the system reliability in the three different types of standby components, i.e., cold, warm and hot standby components, are calculated. Also, it is assumed that the stress and the strength components follow the Weibull distribution and the Weibull process, respectively. The maximum likelihood estimators of the redundancy system reliability are obtained. In addition, a simulation study is performed based on the Monte Carlo method. Finally, the results are illustrated via a practical example that is the time of successive failures of the air conditioning system of every member of a fleet of jet airplanes.

Strategic perspective of error management, the role of leadership, and an error management culture: a mediation model

PurposeErrors are inevitable, resulting from the human condition itself, system failures and the interaction of both. It is essential to know how to deal with their occurrence, managing them. However, the negative tone associated with them makes it difficult for most organizations to talk about mistakes clearly and transparently, for fear of being harmed, preventing their detection, treatment and recovery. Consequently, errors are not managed, remaining accumulated in the system, turning into successive failures. Organizations need to recognize the inevitability of errors, making the system robust, through leadership and an organizational culture of error management. This study aims to understand the role of these influencing variables in an error management approach.Design/methodology/approachIn this paper, the authors applied the methodology of a quantitative nature based on a questionnaire survey that analyses error management, leadership and the organizational culture of error management of 380 workers in Portuguese companies.FindingsThe results demonstrate that leadership directly influences error management and indirectly through the organizational culture of error management, giving this last variable a mediating role.Originality/valueThe study covers companies from different sectors of activity on a topic that is little explored in Portugal, but part of the daily life of organizations, which should deserve greater attention from directors and managers, as they assume a privileged position to promote and develop error management mechanisms. Error management must be the daily work of leaders. This study contributes to theoretical knowledge and business practice on error management.

Effect of Incentives on Motivation Achievement of Jordanian University Football Players

The study aimed at identifying Effect of Incentives on Motivation Achievement of Jordanian University Football Players in the Jordanian universities. The study adopted the descriptive approach, and the study population consisted of (72) football players in Jordanian universities (Yarmouk University, University of Jordan, and Mutah University). The sample consisted of (27) players, who were randomly chosen, comprising (37.35%) of the study population. The researchers constructed the incentives questionnaire that included (30) items distributed over five domains: (physical and health incentives, material incentives, psychological incentives, social incentives, and administrative incentives). They further used the sports achievement motivation scale that was Arabized by Allawi [2], which included (20) items divided into two areas (the motivation to achieve success, and the motivation to avoid failure). The study results showed that the level of the total incentives among the soccer players in the Jordanian universities was very high. The physical, health, social and psychological incentives levels were very high; meanwhile, the administrative and material incentives levels were high. The results further showed that the overall motivation level among the football players in the Jordanian universities was high, as well as the success achievement motivation and failure avoidance motivation levels, which were high too. Finally, there was a correlational relation between the success achievement motivation domain and the motivations areas, as a whole. The study recommended placing special care to the incentives provided to the players as they contribute to the development of the players' innovative energies.

The Effectiveness of Community Participation in Urban Water Supply: A Narrative Review

Debates on the effectiveness of top-down versus bottom-up approaches in water management in urban areas are still ongoing. This study examines the effectiveness of community participation as a bottom-up approach. The narrative review is employed to describe 16 cases of community participation. Three themes emerge from the case studies: the success story and failure of community participation from outside of Indonesia, lessons learned and best practices of community participation from Indonesia, and self-supply as an alternative water provision. Then a discussion of the findings based on the themes found in the literature was carried out. The study found that community participation would be successful if the participatory elements were satisfied, including sufficient capacity and knowledge of the community involved to ensure meaningful participation, involving local government in the education of how to manage and conserve water supply, and involving women in project sustainability. Hence, a pure community participation approach, particularly in disadvantaged urban areas, cannot be achieved. Therefore, a holistic approach combining a top-down and a bottom-up approach is recommended. Self-supply water provision emerged as another method that has largely been ignored by the government and academia but serves as a common practice, particularly in developing countries.

Resilience Assessment of an Urban Rail Transit Network Under Short-Term Operational Disturbances

Operational disturbances within 30 min, namely, short-term operational disturbances (STODs), occur frequently during the daily operation of an urban rail transit (URT) system. Therefore, there is an urgent need to assess a network’s ability to respond to STODs to improve its operational level. The resilience of a URT network jointly considering turn-back operations, the occurrence time of STODs, and passenger travel experience is addressed. By considering passenger travel alternatives under STODs, we assessed the resilience of a network by utilizing the ratio of the average loss of a time-dependent performance indicator, which is referred to as the operational service level indicator in this paper. A simulation-based resilience assessment flowchart is also proposed. Numerical experiments conducted on the Chengdu subway network indicate that this network is more resilient to successive station failure than to simultaneous failure. Guaranteeing the normal operation of transfer stations is vital for enhancing the resilience of a network. The metric proposed in this paper is more practical for assessing resilience than the two commonly used metrics (performance loss and disturbance duration). Additionally, the experimental results highlight that turn-back operations at the stations have a significant impact on the resilience of a URT network. The sensitivity analysis of the parameters indicates that ensuring the normal operation of links connected by critical stations, preventing large-scale station failure, improving passenger tolerance to disturbance durations, and restoring the connectivity of disrupted links rapidly have practical significance for enhancing the resilience of a network.

EEG-Induced Autonomous Game-Teaching to a Robot Arm by Human Trainers Using Reinforcement Learning

Thisarticle deals with a simple indoor game, where the player has to pass a ball through a ring fixed on a variable pan-tilt platform. The motivation of the research is to learn the gaming actions of an experienced player by a robot arm for subsequent training to younger children (trainee) by the robot. The robot learns the gaming actions of the player at different game states, determined by pan-tilt orientations of the ring and its radial distance with respect to the player. The actions of the experienced player/expert are defined by six parameters: three junction-coordinates in the right arm of the player and the three-dimensional speed of the ball in a given throw. Reinforcement learning is employed here to adapt a state-action probability matrix (SAPM) of a probabilistic learning automaton based on the reward (or penalty) scores of the player due to the success (or failure) in passing the ball through a given ring. A hybrid brain-computer interface is used to detect the failures in the gaming action of the player by natural arousal of error-related potential (ErrP) signal following motor execution, indicated by motor imageries. In absence (presence) of ErrP after a motor imagination, the system considers a success (failure) in the player's trials, and thus adapts the probabilities in the learning automata according to success/failure of individual game instances. After the convergence of the SAPM, the same is used for planning, where the action corresponding to the highest probability at a given state in the automaton is selected for execution. The robot can autonomously train the game to the children using the learning automaton with converged probability scores. Experiments undertaken confirm that the success rate of the robot arm in the motor execution phase is very high (above 90%) when the ring is placed at a moderate distance of 4 feet from the robot.

Successful Strategies for Transferring a Family Business from One Generation to the Next

Family businesses make a significant contribution to China's GDP, providing jobs and opportunities for many to showcase themselves. However, family businesses must face several challenges, one of the most important of which is succession. My research is a qualitative study of the strategies used by different business families to pass the family business from one generation to the next. The findings support previous research that most family businesses deplete the company's resources during the succession process, resulting in failure of the succession and bankruptcy of the company. Succession fails for many reasons, such as lack of preparation. My data shows that the enthusiasm of the successor is more important than the education. Effective communication, establishing long-term goals and clear governance rules, and being well prepared also play an important role in avoiding succession failure. The findings of this work have practical and theoretical implications.

Experimental and numerical studies on successive failures of two mooring lines of a net cage subjected to currents

This study investigates the hydrodynamic changes due to successive failures of two mooring lines on a net cage that are subjected to currents using model tests and numerical simulations. An eight-point mooring net-cage model with two electromagnets, which are used to disconnect its upstream mooring lines, is installed in a water flume. The experiment is conducted to measure the lateral mooring forces, rigid-body motions, and remaining volume of the net cage under successive mooring-failure conditions. To reduce the experimental difficulty, successive failures of the mooring lines are forced to occur at 10 and 30 s after the beginning of measurement. A numerical simulation, which is specifically designed for the model test, is also conducted. The results reveal that as the second upstream mooring line fails, the mooring load of the lateral lines, vertical and horizontal movements of the floating collar and tube sinker, and remaining volume of the net cage obviously increase. The values are much larger than those at the first upstream-line failure. The yaw motion of the floating collar increases as the first failure occurs, but it reverts to its origin after the second failure. Comparison of the simulation and experimental results shows good agreement in terms of the mooring force, especially for velocities less than 20 cm/s. The numerical simulations of the body motions of the floating collar and tube sinker and the remaining volume of the net cage are also similar to the experimental results. However, the simulation results of the motion response of the floating collar and the tube sinker after the second failure are obviously smaller than the experimental results.

Combined Inhibition of CDK2 and BCL2 Overrides Resistance to Targeting BTK and CDK4/6 in Mantle Cell Lymphoma Therapy

Mantle cell lymphoma (MCL) remains incurable due to the development of drug resistance, despite the plethora of therapies available. Each successive treatment failure is associated with a more rapidly proliferating disease and fewer treatment options. Understanding the drug-resistance mechanism and developing effective, well-tolerated, new therapies for MCL are urgently needed. Unrestrained proliferation of MCL cells is mainly driven by aberrant cyclin D1 expression and dysregulated CDK4 activity that promotes cell cycle progression from G1 to S. In our phase 1 clinical trial inhibiting CDK4/6 with palbociclib and BTK with ibrutinib (PALIBR) in recurrent MCL, the complete response rate (CR) was 42% compared to 21% in response to ibrutinib alone, despite a comparable 67% overall response rate. Moreover, 5 patients remain on therapy (2 CR and 3 PR) for ~ 8 years, suggesting that CDK4/6 inhibition deepens and prolongs the clinical response to BTK inhibition in MCL. However, resistance emerges in some patients. To elucidate the underpinnings, we undertook integrative longitudinal genomic analysis of sequential tissue and blood specimens (n=53) of 27 MCL patients before, during therapy and on progression, and 4 treatment-naïve MCL patients and 4 normal subjects as controls. Whole exome and whole transcriptome sequencing of freshly isolated MCL cells and B cells revealed that resistance to PALIBR is rooted in homozygous deletion of RB1 (direct target of CDK4/6) or compound copy number variation (cCNV) - concurrent hemizygous loss of RB1 and CDKN2A (p16, CDK4/6 inhibitor) and gain of CDK4. In other resistant patients, the RB protein is silenced by translational termination mutation. Single-cell RNA-sequencing (scRNA-seq, 210,000 cells) of corresponding PBMCs using a unique in-house MCL RNA reference library reveals that MCL cells comprise 4 transcriptomically distinct clusters. Cluster 1 (C1) is similar to quiescent normal B cells; C2 resembles hyper-activated B cells enriched for signatures of BCR and cytokine signaling; C3 represents non-proliferating, long-lived MCL cells; and C4 is highly proliferative, expanding with disease progression. RNA velocity analysis further uncovered that C2 fuels the transition to C4 with disease progression, whereas C3 is a terminal node (Fig 1). In C2 and C3 MCL cells, CDK2 is highly elevated, indicating evasion of CDK4/6 inhibition, and PIK3IP1 (negative PI3K regulator) is silenced, suggesting that compensatory PI3K activation in BTKi resistance (Chiron et al, Cancer Discovery 2014) is secondary to loss of cell cycle control. BCL2 is markedly elevated in C2, greater in C3 MCL cells along with increases in anti-apoptotic BCL2L1(BCL-XL) and BCL-2A1 and decreases in pro-apoptotic PMAIP1 (NOXA) expression. This suggests combined CDK2 and BCL2 inhibition as a rational approach to override CDK4/6i and BTKi resistance. Indeed, combined inhibition of CDK2 with PF-07104091 and BCL2 with venetoclax (PF-VEN) cooperatively impaired growth and killed ibrutinib-resistant MAVER-1 cells, more effectively in the isogenic derivative MAVER-1R cells which we generated to recapitulate cCNV in PALIBR resistance - depletion of RB protein through translational termination mutation (W99, AAF 75%) in RB1, loss of CDKN2A and gain of CDK4. Mechanistically, MAVER-1R cells are accelerated in G1 to S progression, based on elevation of CDK2 and TK1 expression and cell cycle profiling. They are intrinsically apoptotic and vulnerable to BCL2 inhibition due to a marked reduction in cells expressing anti-apoptotic BCL2L1 and IRF4, and universal expression of pro-apoptotic PMAIP1 (NOXA). Importantly, combined CDK2 and BCL2 inhibition synergistically kills MCL cells of a patient resistant to PALIBR ex vivo. In summary, by longitudinal genomic analysis, we have provided the first evidence that 1) resistance to CDK4/6i and BTKi stems from MCL intrinsic cCNV; 2) MCL cells comprise 4 major transcriptomically distinct clusters; cluster 2 expressing copious CDK2 and BCL2 is pivotal in fueling proliferation of MCL cells in resistance; 3) cluster 3 cells also accumulate with resistance due to longevity; 4) combined inhibition of CDK2 and BCL2 overrides resistance to CDK4i and BTKi, in MCL cell lines and primary MCL cells from PALIBR resistant patient. Combined inhibition of CDK2 and BCL2, therefore, represents a mechanism-based strategy to overcome CDK4/6i and BTKi resistance in MCL therapy. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Percent Patient NK and T Cells at Day 28 Predict Graft Outcome after Haploidentical Hematopoietic Cell Transplant for Sickle Cell Disease

The only definitive cure for sickle cell disease (SCD) is hematopoietic cell transplant (HCT). Donor options are often limited due to the requirement of having a human leukocyte antigen (HLA)-matched donor. A haploidentical HCT from a family member has the potential to increase the donor pool for HCTs in SCD patients; however, conditioning regimens remain toxic. Reduced-intensity conditioning has the potential to successfully deplete the host immune system, reducing the rate of graft failure while also avoiding toxic side effects of traditional regimens. Natural killer (NK) cells are among the first cell lineages to repopulate following HCT, so sufficient depletion is necessary to ensure that the patient's NK cells will not target the donor cells post HCT. The primary objective of this study was to determine if a high percentage of patient NK cells at day 28 post-transplant could predict successful engraftment versus graft failure in SCD patients that have received a haploidentical HCT. Whole blood was drawn from SCD patients and their donors from two clinical trials (ClinicalTrials.gov Identifier: NCT02165007, NCT03077542) at baseline (before HCT) and at days 28, 60, 100, 180, and 365 following HCT. Peripheral blood mononuclear cells (PBMCs) were isolated via gradient-dependent lymphocyte separation and frozen for future batch analysis. Once samples from all time points were received, PBMCs were thawed and stained with fluorescent antibodies against CD3, CD4, CD8, CD45, CD56, iNKT, NKG2D, and HLA and analyzed by flow cytometry. HLA antibody optimization was achieved by screening for HLA mismatches between a patient and their haploidentical donor. Mann-Wilcoxon-Whitney rank tests were used to identify significant differences in various cell populations (CD3-CD56+ NK cells, CD3+ T cells) between patients with successful engraftment and those with graft failure. Areas under the receiver operating characteristic curve (AUCs) of the cell populations were used to determine which immune cell lineage held the highest potential to predict HCT graft failure at day 28. Statistical significance was established at p<0.05. A total of 15 patients were analyzed in this study: 11 patients had successful engraftment and 4 had graft failure. There were no statistically significant differences in the pre-HCT % NK or % T cell values in those who engrafted versus those who failed to engraft. At day 28 post-HCT, significant differences were noted between the % NK cells of all lymphocytes (p=0.0151) and % T cells of all lymphocytes (p=0.0028), as well as %-patient NK cells (p=0.0029) and %-patient T cells (p=0.0055) between the engrafted population and the graft failure population [Figure 1, A,B]. NK cells of all lymphocytes had an AUC of 0.9038 (95% Confidence Interval, CI, 0.573-1.00). T cells of all lymphocytes had an AUC of 0.9385 (95% CI 0.827-1.00). The AUC for %-patient T cells was 0.9273 (95% CI 0.779-1.00). Lastly, the AUC for %-patient NK cells was 0.9773 (95% CI 0.909-1.00). This suggested that the %-patient NK cells ROC model had the highest potential to correctly classify engraftment vs graft failure. This study showed the potential for using %-patient NK cells to predict graft failure at day 28 in SCD patients after haploidentical HCT, however, the sample size was limited. To independently validate these findings, analyses of specimens from a multisite clinical trial are being performed. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Abstract 12278: Relationship Between Amiodarone Response Prior to Ablation and One Year Outcomes of Catheter Ablation for Atrial Fibrillation

Introduction: Catheter ablation for atrial fibrillation is a common therapeutic strategy for paroxysmal and persistent AF patients, but long-term success rates are imperfect. Maintenance of sinus rhythm prior to ablation with antiarrhythmic drug therapy has improved outcomes in patients undergoing ablation compared to ablation procedure alone. Amiodarone has superior efficacy relative to other AADs. Whether the failure of amiodarone to maintain sinus rhythm prior to ablation is a predictor of poor outcomes is unknown. Methods: Total 307 patients received amiodarone in a span of 1y before undergoing catheter ablation for AF from January 2014 to March 2019. Patients were divided into amiodarone success (n=183) and amiodarone failure (n=124) groups based on the response to pre-ablation amiodarone treatment. Follow-up was done for 12 months post-ablation to assess outcomes (arrhythmia recurrence and adverse events). Procedural success was defined by the absence of documented arrhythmia (&gt;30s) without any antiarrhythmic agents beyond a 90d blanking period. Results: Ablation procedure success rate at 1y was 57.7% overall. 1y success rate in the amiodarone success group was comparable to that in the amiodarone failure group (55.7% vs. 60.5%; p=0.54). Success rates following ablation did not vary by the response to amiodarone when analyzed for paroxysmal or persistent AF subgroups. Conclusion: Failure to restore and maintain sinus rhythm on amiodarone therapy is not a predictor of adverse ablation procedure outcomes and should not be used as a patient selection criteria for consideration of ablation.

The Decision-Making for the Optimization of Finance Lease with Facilities’ Two-Dimensional Deterioration

In the past, most companies in developing countries usually own facilities or equipment for running their businesses. However, for some managerial and financial reasons, the situation may change. Recently, leasing facilities is becoming more popular than purchasing them. Furthermore, since the deterioration of equipment or facilities depends on both time and usage, when considering only one of the two factors, the deterioration estimation for the leased facilities could be distorted. Therefore, in such cases, a two-dimensional failure model would be appropriate for dealing with such problems. In this study, in order to determine the optimal lease decision for lessors, we use analytical models and efficient solution algorithms based on the two deterioration factors (time and usage). However, such complex mathematical models are difficult to apply in real cases, and therefore the study proposes the design of computerized system architecture and the corresponding solution algorithms to enhance the practicality of the applications. Besides, a nonhomogeneous Poisson process is employed to describe the successive failure times of the leased facility. Finally, the application and sensitivity analyses will provide managerial implications and suggestions for decision-makers under different preventive maintenance alternatives.

The Agnoiological Nature of Modern Epistemology: Grounding Knowledge by Ignorance

One of the distinguishing features of modern and contemporary philosophy is the fact that they are consistently grounded by the epistemological outlook. The essence of this outlook is the modern conception of knowledge, which could not exist without a proper evaluation of a systemic success — or, even more importantly, in some sense a successful failure — of modern science. The only way for us to perceive the lack of error as the basis of a reliable knowledge is to recognize our own fallacies. In such a way the ancient cosmocentrical worldview and the medieval theocentrical epistemology have been changed by the scientistic agnoiological approach, which had its origins in the modern times and includes the primary requirement to treat the fundamental ignorance as a reliable foundation of knowledge. In this article the reader is provided with a detailed exposition of the phenomenon of self-grounding of epistemological modernity. Adopting the terminology used in the metaphilosophical reflexion, we could reveal the dual origin of contemporary philosophical discourse, the basic principles which ground the epistemological claims, and also demonstrate the necessity of constant efforts when seeking to avoid solipsism and the paradoxical nature of modern epistemology.

Sonographic assessment of diaphragmatic thickening and excursion as predictors of weaning success in the intensive care unit: A prospective observational study.

Ultrasonographic assessment of diaphragmatic function can be a useful bedside tool in the weaning and extubation of mechanically ventilated patients, especially in patients with difficult weaning, in whom diaphragmatic weakness is suspected. Thus, this study was planned to assess the role of bedside sonographic assessment of diaphragmatic indices such as diaphragmatic thickening fraction (DTf) and diaphragmatic excursion (DE) in predicting successful extubation or extubation failure in weaning eligible patients by comparing the measurements with outcome. This prospective observational study was conducted on 50 mechanically ventilated, weaning-ready patients during the spontaneous breathing trial (SBT). The DE and DTf of patients were noted along with conventional parameters of weaning. Probability value <0.05 was considered statistically significant. Receiver operating characteristic (ROC) curves were used for analysis. Area under the curve (AUC) was measured, and sensitivity and specificity for different cut-off values were estimated. Out of 50 patients, 15 (30%) had SBT failure and 4 had extubation failure. The group with SBT failure had significantly higher rapid shallow breathing index (RSBI) and airway occlusion pressure (P0.1s), whereas DE and DTf were lower compared to the SBT successful group. Strong correlation existed between RSBI, DTf, DE and P0.1s. DTf of nearly 24% (sensitivity 93.5%, specificity 94.7%) and DE of 1.10 cm (84% sensitivity, 89.5% specificity) were associated with best outcome. Along with conventional parameters of weaning, sonographic assessment of diaphragmatic parameters can be useful in predicting the success of SBT and in avoiding unnecessary extubation failures and thereby help in achieving a successful weaning outcome.

An improved reactive power control strategy for LCC-HVDC to mitigate sending end transient voltage disturbance caused by commutation failures

The sending end transient voltage disturbance (TVD) caused by commutation failure of line commutated converter-based high voltage direct current (LCC-HVDC) systems, which is characterized by “first reduce then rise”, has received increasing attention due to its threat to the stable operation of renewable energy integrated modern power systems. To mitigate the TVD, this paper devises an improved reactive power control strategy that takes into account the signal delay between converter stations. Firstly, the mechanism of the TVD is investigated. It is found that the voltage dependent current order limiter (VDCOL) and signal delay between the rectifier and the inverter stations are two vital factors that impact the TVD, while the VDCOL cannot well cope with commutation failure suppression and TVD mitigation at the same time. On this basis, an improved closed-loop reactive power control (CLRPC) strategy is proposed for the LCC-HVDC to mitigate the TVD. The CLRPC can regulate the reactive power demand of the rectifier station by adjusting the DC current order, which replaces the conventional VDCOL during the disturbance. Furtherly, a delay compensation unit is augmented in the proposed scheme to suppress the adverse effect of signal delay. Simulation results conducted in PSCAD/EMTDC verify that the CLRPC can not only alleviate the TVD effectively but also suppress the occurrence of successive commutation failures, thus, enhancing the overall performance of the sending end power system.

The Impact of Higher Protein Intake in Patients with Prolonged Mechanical Ventilation.

Prolonged mechanical ventilation (PMV) is associated with poor outcomes and a high economic cost. The association between protein intake and PMV has rarely been investigated in previous studies. This study aimed to investigate the impact of protein intake on weaning from mechanical ventilation. Patients with the PMV (mechanical ventilation ≥6 h/day for ≥21 days) at our hospital between December 2020 and April 2022 were included in this study. Demographic data, nutrition records, laboratory data, weaning conditions, and survival data were retrieved from the patient’s electronic medical records. A total of 172 patients were eligible for analysis. The patients were divided into two groups: weaning success (n = 109) and weaning failure (n = 63). Patients with daily protein intake greater than 1.2 g/kg/day had significant shorter median days of ventilator use than those with less daily protein intake (36.5 vs. 114 days, respectively, p < 0.0001). Daily protein intake ≥1.065 g/kg/day (odds ratio: 4.97, p = 0.033), daily protein intake ≥1.2 g/kg/day (odds ratio: 89.07, p = 0.001), improvement of serum albumin (odds ratio: 3.68, p = 0.027), and BMI (odds ratio: 1.235, p = 0.014) were independent predictor for successful weaning. The serum creatinine level in the 4th week remained similar in patients with daily protein intake either >1.065 g/kg/day or >1.2 g/kg/day (p = 0.5219 and p = 0.7796, respectively). Higher protein intake may have benefits in weaning in patients with PMV and had no negative impact on renal function.

Outcomes and affecting factors for ICSI and microTESE treatments in nonobstructive azoospermia patients with different etiologies: A retrospective analysis.

Nonobstructive azoospermia (NOA) is a common and severe form of male infertility. Microdissection testicular sperm extraction (microTESE) combined with intracytoplasmic sperm injection (ICSI) is an optimal treatment for men with NOA. However, the outcomes and affecting factors of ICSI for NOA patients with different etiologies receiving microTESE treatment are still unclear. A total of 335 NOA patients undergoing microTESE from January 2017 to December 2021 were included in this retrospective analysis. The patients were divided into five groups (idiopathic, Klinefelter syndrome (KS), Y chromosome microdeletions (YCMDs), cryptorchidism and mumps orchitis) according to the etiologies. The clinical characteristics and outcomes of microTESE and ICSI were collected and comparisons were performed between clinical characteristics of patients who had successful sperm retrieval (SSR) and sperm retrieval failure (SRF). In addition, relationships between clinical characteristics and rates of SSR were explored by Kendall correlation analysis. The overall SSR rate was 40.90%. SSR rate of the idiopathic group (31.22%) was the lowest and was much lower than that of other groups (KS: 48.65%, 28/58; YCMDs: 60.87%; cryptorchidism: 80.95%; mumps orchitis: 75.00%). The overall fertilization rate was 72.26%. No group differences were found among five groups (idiopathic: 73.91%; KS: 71.43%; YCMDs: 64.29%; cryptorchidism: 70.59%; mumps orchitis: 77.78%). The overall clinical pregnancy rate was 66.67%. No group differences were found among five groups (idiopathic: 68.63%; KS: 65.00%; YCMDs: 44.44%; cryptorchidism: 66.67%; mumps orchitis: 85.71%). The overall live birth rate was 66.67%. No group differences were found among five groups (idiopathic: 71.43%; KS: 53.85%; YCMDs: 50.00%; cryptorchidism: 75.00%; mumps orchitis: 66.67%). For SSR patients, the average age was significantly lower in the idiopathic group, while the average testicular volume was significantly greater in the cryptorchidism and mumps orchitis groups. However, no significant differences were found in the level of follicle stimulating hormone (FSH), luteinizing hormone (LH) and testosterone (T) between patients who had SSR and SRF. In addition, negative relationships were found between age and rates of SSR in idiopathic NOA patients while positive relationships were found between testis volume and rates of SSR in patients with cryptorchidism and mumps orchitis. Patients with idiopathic NOA had lowest SSR. In addition, the age in idiopathic NOA patients was a predictor for SSR while testicular volume in NOA patients with cryptorchidism and mumps orchitis was a predictor for SSR. However, the relationships between clinical characteristics and clinical outcomes in NOA patients were preliminary, and further validation needed to be carried out in a larger sample to increase statistical capacity before a definitive conclusion could be drawn.