关于Client/Sever数据库系统安全机制的分类

首先介绍了 Ｃｌｉｅｎｔ／ Ｓｅｖｅｒ数据库系统的概念，然后对其安全机制进行了总结和分析，提出并阐述了某“关于Ｃｌｉｅｎｔ／Ｓｅｖｅｒ系统安全机制的分类”观点。

Effect of safety valve types on the gas venting behavior and thermal runaway hazard severity of large-format prismatic lithium iron phosphate batteries

The safety valve is an important component to ensure the safe operation of lithium-ion batteries(LIBs).However,the effect of safety valve type on the thermal runaway(TR)and gas venting behavior of LIBs,as well as the TR hazard severity of LIBs,are not known.In this paper,the TR and gas venting behavior of three 100 A h lithium iron phosphate(LFP)batteries with different safety valves are investigated under overheating.Compared to previous studies,the main contribution of this work is in studying and evaluating the effect of gas venting behavior and TR hazard severity of LFP batteries with three safety valve types.Two significant results are obtained:(Ⅰ)the safety valve type dominates over gas venting pressure of battery during safety venting,the maximum gas venting pressure of LFP batteries with a round safety valve is 3320 Pa,which is one order of magnitude higher than other batteries with oval or cavity safety valve;(Ⅱ)the LFP battery with oval safety valve has the lowest TR hazard as shown by the TR hazard assessment model based on gray-fuzzy analytic hierarchy process.This study reveals the effect of safety valve type on TR and gas venting,providing a clear direction for the safety valve design.

Computerized tomography-guided therapeutic percutaneous puncture catheter drainage-combined with somatostatin for severe acute pancreatitis: An analysis of efficacy and safety

BACKGROUND Severe acute pancreatitis(SAP),a condition with rapid onset,critical condition and unsatisfactory prognosis,poses a certain threat to human health,warranting optimization of relevant treatment plans to improve treatment efficacy.AIM To evaluate the efficacy and safety of computerized tomography-guided the-rapeutic percutaneous puncture catheter drainage(CT-TPPCD)combined with somatostatin(SS)in the treatment of SAP.METHODS Forty-two SAP patients admitted to The Second Affiliated Hospital of Fujian Medical University from June 2020 to June 2023 were selected.On the basis of routine treatment,20 patients received SS therapy(control group)and 22 patients were given CT-TPPCD plus SS intervention(research group).The efficacy,safety(pancreatic fistula,intra-abdominal hemorrhage,sepsis,and organ dysfunction syndrome),abdominal bloating and pain relief time,bowel recovery time,hospital stay,inflammatory indicators(C-reactive protein,interleukin-6,and pro-calcitonin),and Acute Physiology and Chronic Health Evaluation(APACHE)II score of both groups were evaluated for comparison.RESULTS Compared with the control group,the research group had a markedly higher total effective rate,faster abdominal bloating and pain relief and bowel recovery,INTRODUCTION Pancreatitis,an inflammatory disease occurring in the pancreatic tissue,is classified as either acute or chronic and is associated with high morbidity and mortality,imposing a socioeconomic burden[1,2].The pathogenesis of this disease involves early protease activation,activation of nuclear factor kappa-B-related inflammatory reactions,and infiltration of immune cells[3].Severe acute pancreatitis(SAP)is a serious condition involving systemic injury and subsequent possible organ failure,accounting for 20%of all acute pancreatitis cases[4].SAP is also characterized by rapid onset,critical illness and unsatisfactory prognosis and is correlated with serious adverse events such as systemic inflammatory response syn-drome and acute lung injury,threatening the health of patients[5,6].Therefore,timely and effective therapeutic inter-ventions are of great significance for improving patient prognosis and ensuring therapeutic effects.Somatostatin(SS),a peptide hormone that can be secreted by endocrine cells and the central nervous system,is in-volved in the regulatory mechanism of glucagon and insulin synthesis in the pancreas[7].It has complex and pleiotropic effects on the gastrointestinal tract,which can inhibit the release of gastrointestinal hormones and negatively modulate the exocrine function of the stomach,pancreas and bile,while exerting a certain influence on the absorption of the di-gestive system[8,9].SS has shown certain clinical effectiveness when applied to SAP patients and can regulate the severity of SAP and immune inflammatory responses,and this regulation is related to its influence on leukocyte apoptosis and adhesion[10,11].Computerized tomography-guided therapeutic percutaneous puncture catheter drainage(CT-TPPCD)is a surgical procedure to collect lesion fluid and pus samples from necrotic lesions and perform puncture and drainage by means of CT image examination and precise positioning[12].In the research of Liu et al[13],CT-TPPCD applied to pa-tients undergoing pancreatic surgery contributes to not only good curative effects but also a low surgical risk.Baudin et al[14]also reported that CT-TPPCD has a clinical success rate of 64.6%in patients with acute infectious necrotizing pan-creatitis,with nonfatal surgery-related complications found in only two cases,suggesting that this procedure is clinically effective and safe in the treatment of the disease.In light of the limited studies on the efficacy and safety of SS plus CT-TPPCD in SAP treatment,this study performed a relevant analysis to improve clinical outcomes in SAP patients.

Evaluation of the Care of Children Aged 0 to 10 Years Hospitalized for Severe Malaria at the Tambacounda Health Center, Senegal

Introduction: Malaria remains a public health priority in Senegal, particularly in Tambacounda, where it is one of the main causes of child mortality. The objective of this work was to evaluate the care of children under 10 years of age hospitalized at the Tambacounda Health Center and the factors associated with recovery. Methods: An analytical, retrospective, and descriptive cross-sectional study with exhaustive recruitment of children 0 to 120 months hospitalized at the Tambacounda reference health center for severe malaria (according to WHO criteria) between 1 January 2018 and 31 December 2021 was performed. Data collection was done through a questionnaire. Records, hospitalization records, and treatment records were the sources of collection. Data entry and analysis were performed on Epi Info 7.2 and R. Results: A total of 481 children hospitalized with severe malaria were recruited. The highest number of cases was recorded in 2018 (33.05%). In the four years of the study, peaks were always observed between October and November and the highest peak in November 2020 with 95 cases. The mean age was 65.64 months with a standard deviation of 29.28 months and a predominance of male (53.43%). The majority of people were admitted from the outpatient clinic (57.79%) and the rest (42.21%) on the recommendation of a peripheral health post. All hospitalized patients had a positive RDT and/or a positive thick drop. However, the sharp decline at admission or during hospitalization was positive in 93.80% of patients in our series, negative in 5.20% and not achieved in 1.00%. Seizures and severe anemia topped the list of signs of severity with 45.94% and 8.11%, respectively. In terms of evolution, for all hospitalized patients, there were 81.29% recovery, 10.19% referral to the Tambacounda regional hospital center for hospitalization, 4.99% death, 0.83% discharge and 2.70% unknown evolution. There was a statistically significant association between recovery without referral from a health post (OR = 1.85), absence of 2 or more signs of severity (OR = 1.82), absence of seizures (OR = 1.51), prostration (OR = 2.78), cardiovascular shock (OR = 6.67), coma (OR = 7.69), lack of evidence of biological severity (OR = 3.70), and hypoglycemia with blood glucose less than 0.4 g/L (OR = 5.88). Conclusion: In addition to the routine malaria prevention and management strategies implemented in Tambacounda, and the early referral of cases of severe malaria from health posts to the health center, all children hospitalized for severe malaria with certain symptomatology such as coma, prostration, cardiovascular shock, etc. Seizures and/or hypoglycemia should be systematically referred to the regional hospital to increase their chance of recovery.

Relationship between mitochondrial respiratory dysfunction of blood mononuclear cells and heart failure severity

Chronic heart failure(CHF)is a clinical syndrome manifested by reduced pumping ability of the heart,increased pressure in heart chambers in both physical activity and at rest.The symptoms of this syndrome are dyspnea,undue fatigability,peripheral edema,which follow structural and functional changes of the myocardium.[1]The growing incidence of CHF,especially among elderly people,is an urgent problem for medicine in the vast majority of industrialized countries.For instance,in Russian Federation,CHF is diagnosed in about 7%of cardiovascular patients.At the same time,this indicator varies from 0.3%in young people(20-29 years old)to 70%in the older age group.[2,3].

ASLP-DL—A Novel Approach Employing Lightweight Deep Learning Framework for Optimizing Accident Severity Level Prediction

Highway safety researchers focus on crash injury severity,utilizing deep learning—specifically,deep neural networks(DNN),deep convolutional neural networks(D-CNN),and deep recurrent neural networks(D-RNN)—as the preferred method for modeling accident severity.Deep learning’s strength lies in handling intricate relation-ships within extensive datasets,making it popular for accident severity level(ASL)prediction and classification.Despite prior success,there is a need for an efficient system recognizing ASL in diverse road conditions.To address this,we present an innovative Accident Severity Level Prediction Deep Learning(ASLP-DL)framework,incorporating DNN,D-CNN,and D-RNN models fine-tuned through iterative hyperparameter selection with Stochastic Gradient Descent.The framework optimizes hidden layers and integrates data augmentation,Gaussian noise,and dropout regularization for improved generalization.Sensitivity and factor contribution analyses identify influential predictors.Evaluated on three diverse crash record databases—NCDB 2018–2019,UK 2015–2020,and US 2016–2021—the D-RNN model excels with an ACC score of 89.0281%,a Roc Area of 0.751,an F-estimate of 0.941,and a Kappa score of 0.0629 over the NCDB dataset.The proposed framework consistently outperforms traditional methods,existing machine learning,and deep learning techniques.

Improving Federated Learning through Abnormal Client Detection and Incentive

Data sharing and privacy protection are made possible by federated learning,which allows for continuous model parameter sharing between several clients and a central server.Multiple reliable and high-quality clients must participate in practical applications for the federated learning global model to be accurate,but because the clients are independent,the central server cannot fully control their behavior.The central server has no way of knowing the correctness of the model parameters provided by each client in this round,so clients may purposefully or unwittingly submit anomalous data,leading to abnormal behavior,such as becoming malicious attackers or defective clients.To reduce their negative consequences,it is crucial to quickly detect these abnormalities and incentivize them.In this paper,we propose a Federated Learning framework for Detecting and Incentivizing Abnormal Clients(FL-DIAC)to accomplish efficient and security federated learning.We build a detector that introduces an auto-encoder for anomaly detection and use it to perform anomaly identification and prevent the involvement of abnormal clients,in particular for the anomaly client detection problem.Among them,before the model parameters are input to the detector,we propose a Fourier transform-based anomaly data detectionmethod for dimensionality reduction in order to reduce the computational complexity.Additionally,we create a credit scorebased incentive structure to encourage clients to participate in training in order tomake clients actively participate.Three training models(CNN,MLP,and ResNet-18)and three datasets(MNIST,Fashion MNIST,and CIFAR-10)have been used in experiments.According to theoretical analysis and experimental findings,the FL-DIAC is superior to other federated learning schemes of the same type in terms of effectiveness.

Two-Stage Client Selection Scheme for Blockchain-Enabled Federated Learning in IoT

Federated learning enables data owners in the Internet of Things(IoT)to collaborate in training models without sharing private data,creating new business opportunities for building a data market.However,in practical operation,there are still some problems with federated learning applications.Blockchain has the characteristics of decentralization,distribution,and security.The blockchain-enabled federated learning further improve the security and performance of model training,while also expanding the application scope of federated learning.Blockchain has natural financial attributes that help establish a federated learning data market.However,the data of federated learning tasks may be distributed across a large number of resource-constrained IoT devices,which have different computing,communication,and storage resources,and the data quality of each device may also vary.Therefore,how to effectively select the clients with the data required for federated learning task is a research hotspot.In this paper,a two-stage client selection scheme for blockchain-enabled federated learning is proposed,which first selects clients that satisfy federated learning task through attribute-based encryption,protecting the attribute privacy of clients.Then blockchain nodes select some clients for local model aggregation by proximal policy optimization algorithm.Experiments show that the model performance of our two-stage client selection scheme is higher than that of other client selection algorithms when some clients are offline and the data quality is poor.

Superplasticity of fine-grained Mg-10Li alloy prepared by severe plastic deformation and understanding its deformation mechanisms

The superplastic behavior and associated deformation mechanisms of a fine-grained Mg-10.1 Li-0.8Al-0.6Zn alloy(LAZ1011)with a grain size of 3.2μm,primarily composed of the BCCβphase and a small amount of the HCPαphase,were examined in a temperature range of 473 K to 623 K.The microstructural refinement of this alloy was achieved by employing high-ratio differential speed rolling.The best superplasticity was achieved at 523 K and at strain rates of 10^(-4)-5×10^(-4)s^(-1),where tensile elongations of 550±600%were obtained.During the heating and holding stage of the tensile samples prior to tensile loading,a significant increase in grain size was observed at temperatures above 573 K.Therefore,it was important to consider this effect when analyzing and understanding the superplastic deformation behavior and mechanisms.In the investigated strain rate range,the superplastic flow at low strain rates was governed by lattice diffusion-controlled grain boundary sliding,while at high strain rates,lattice diffusion-controlled dislocation climb creep was the rate-controlling deformation mechanism.It was concluded that solute drag creep is unlikely to occur.During the late stages of deformation at 523 K,it was observed that grain boundary sliding led to the agglomeration of theαphase,resulting in significant strain hardening.Deformation mechanism maps were constructed forβ-Mg-Li alloys in the form of 2D and 3D formats as a function of strain rate,stress,temperature,and grain size,using the constitutive equations for various deformation mechanisms derived based on the data of the current tests.

Management of Severely Malnourished Children Aged 6 - 59 Months Hospitalized in the Pediatric Ward of Kayanza Hospital/Burundi

The implementation of WHO guidelines has significantly reduced hospital mortality due to severe malnutrition. Nevertheless, severe acute malnutrition in children under five remains a major public health problem in all low-income countries and is little studied. The study aimed to assess the nutritional status and quality of management of severe acute malnutrition in children aged 06 to 59 months hospitalized in the pediatric ward of Kayanza Hospital. This is a prospective study with descriptive and analytical aims over 6 months from February 10 to July 9, 2023. All children aged 6 to 59 months admitted for severe acute malnutrition are included in this study. The results show that the most affected age group is 12 to 23 months (42.55%). Marasmus is the most common clinical form, at 70.2%. Housewives and mothers from rural areas are the most affected, with rates ranging from 69.14% to 91.49%. The study shows that the reasons for consultation are respectively: edema (29.78%), diarrhea (26.59%), vomiting (19.14%), and fever (14.89%). Dehydration and hypothermia were the main complications observed in 45.74% and 22.34% respectively. Medical treatment was provided by antibiotics (44.68%), artesunate (31.91%), and resomal (21.27%). Nutritional treatment consisted of F75 100% milk and F100 100% milk. Pathologies observed were: anemia 38.29%, malaria 37.23%, urinary tract infection 12.7%, measles 11.7%. The national protocol for integrated management of acute malnutrition (PCIMA) was followed. This study shows that 72.3% of children were successfully treated, with 9.5% dropping out and dying, and 8.5% not responding. We found that malnutrition remains a public health problem, affecting mostly children aged 12 to 24 months. The main complications or pathologies associated with malnutrition are diarrhea, malaria, and fever, and the majority of children suffer from marasmus.

Radial growth in Qinghai spruce is most sensitive to severe drought in the Qilian Mountains of Northwest China

Global warming and frequent extreme drought events lead to tree death and extensive forest decline,but the underlying mechanism is not clear.In drought years,cambial development is more sensitive to climate change,but in different phenological stages,the response rela-tionship is nonlinear.Therefore,the dynamic relationship between tree radial growth and climatic/environmental fac-tors needs to be studied.We thus continuously monitored radial growth of Qinghai spruce(Picea crassifolia Kom.)and environmental factors from January 2021 to November 2022 using point dendrometers and portable meteorological weather stations in the central area of the Qilian Mountains.The relationship and stability between the radial growth of Qinghai spruce and environmental factors were compared for different levels of drought in 2021 and 2022.The year 2022 had higher temperatures and less precipitation and was drier than 2021.Compared with 2021,the growing period in 2022 for Qinghai spruce was 10 days shorter,maximum growth rate(Grmax)was 4.5μm·d^(-1) slower,and the initiation of growth was 6 days later.Growth of Qinghai spruce was always restricted by drought,and the stem radial increment(SRI)was more sensitive to precipitation and air relative humidity.Seasonal changes in cumulative radial growth were divided into four phenological stages according to the time of growth onset,cessation,and maximum growth rate(Grmax)of Qinghai spruce.Stability responses of SRI to climate change were stronger in Stage 3 and Stage 4 of 2021 and stronger in Stage 1(initiation growth stage)and Stage 3 of 2022.The results provide important information on the growth of the trees in response to drought and for specific managing forests as the climate warms.

Association between Placental Malaria and Severe Pre-Eclampsia in Two University Hospitals of Yaounde City

Context: Pre-eclampsia and placental malaria, are two diseases that share pathophysiological similarities, such as placental ischemia, endothelial dysfunction and production of pro-inflammatory cytokines. Objective: The objective of our study was to investigate the association between placental malaria lesions and severe pre-eclampsia. Methodology: We conducted a prospective analytical cross-sectional study in two University Hospitals in the city of Yaounde (Yaounde Central Hospital and the Gynaecological Obstetrics and Paediatrics Hospital), and in the laboratory of the Centre Pasteur in Yaounde over an eight-month period (1st January 2021 – 1st September 2021). All patients with pre-eclampsia diagnosed according to the criteria of the International Society for the Study of Hypertension (ISSHP) and free of chronic metabolic or infectious pathology were included in this study. The patients were divided into two groups: group 1 (mild pre-eclampsia) and group 2: severe pre-eclampsia. Socio-demographic, clinical and histopathological characteristics specific to pre-eclampsia and placental malaria were investigated. Statistical analysis was performed with SPSS 23.0 software, Chi 2 was used to compare categorical variables, Student t-test was used to compare means, and logistic regression was used to assess the association between placental malaria lesions and PES. Results: The mean age of our study population was 29.93 ± 7.36 years versus 28.28 ± 7.18 years in patients with mild and severe pre-eclampsia respectively. Pre-eclampsia placental lesions (accelerated villous maturation, infarction) were significantly greater in patients with severe pre-eclampsia (p Conclusion: Placental malaria lesions were significantly associated with severe pre-eclampsia and increased the risk of developing severe pre-eclampsia placental lesions by a factor of 10.

Clinical and Evolutive Aspects of Severe Acute Malnutrition in Children Aged 0 - 59 Months at Maroua Regional Hospital in Cameroon’s Far North Region

Introduction: Severe acute malnutrition remains one of the most important causes of under-five mortality. In Cameroon, the northern regions have the highest prevalence, with 1.4% in the Far North in 2021. These children are managed at the Internal therapeutic and Nutrional Centre, one of which is located at Maroua Regional Hospital, the third level referral Hospital. We therefore proposed to carry out a study on the clinical and evolutive aspects of these children. Materials and Methods: it was a descriptive, cross-sectional study from January 2020 to December 2022, at the ITNC (CNTI) of Maroua Regional Hospital. The sample size was obtained from the Lorentz formula. Patient records were used for data collection. We excluded all incomplete records and patients with less than 24 hours of admission. Results: Out of the 873 patients we recruited, the prevalence of severe malnutrition was estimated at 18 %. The average age was 14 months, with a male predominance. The main reasons for consultation were fever (42%) and diarrhoea (35%). Marasmus was the predominant clinical form. The major medical complications were sepsis (32.9%) and malaria (16.8%). HIV prevalence was 2.5% and tuberculosis was 4.9%. Most patients had haemoglobin levels between 7 and 10g/dl. 79.3% were cured and 6.5% died. The main causes of death were sepsis and malaria. Conclusion: Severe acute malnutrition remains a major problem in the Far North region. Several joint actions are needed to break this cycle.

Efficacy and safety of carrimycin in ten patients with severe pneumonia following solid organ transplantation

BACKGROUND The number of patients undergoing solid organ transplantation has increased annually.However,infections in solid organ transplant recipients can have a severe effect on patient survival owing to the continued use of immunosuppressants.Carrimycin is a novel macrolide antibiotic produced by genetically engineered streptomyces spiramyceticus harboring a 4’’-O-isovaleryltransferase gene(ist)from streptomyces thermotoleran.Carrimycin has good antibacterial and antiviral effects.However,no relevant studies have been conducted on the efficacy and safety of carrimycin in patients with severe pneumonia(SP)after solid organ transplantation.AIM To explore the efficacy and safety of carrimycin in patients with SP after solid organ transplantation to provide a medication reference for clinical treatment.METHODS In March 2022,ten patients with SP following solid-organ transplantation were treated at our hospital between January 2021 and March 2022.When the condition was critical and difficult to control with other drugs,carrimycin was administered.These ten patients'clinical features and treatment protocols were retrospectively analyzed,and the efficacy and safety of carrimycin for treating SP following solid organ transplantation were evaluated.RESULTS All ten patients were included in the analysis.Regarding etiological agent detection,there were three cases of fungal pneumonia,two cases of bacterial pneumonia,two cases of Pneumocystis pneumonia,and three cases of mixed infections.After treatment with carrimycin,the disease in seven patients significantly improved,the course of the disease was significantly shortened,fever was quickly controlled,chest computed tomography was significantly improved,and oxygenation was significantly improved.Finally,the patients were discharged after curing.One patient died of acute respiratory distress syndrome,and two patients discontinued treatment.CONCLUSION Carrimycin is a safe and effective treatment modality for SP following solid organ transplantation.Carrimycin may have antibacterial and antiviral effects in patients with SP following solid organ transplantation.

Successful management of severe hypoglycemia induced by total parenteral nutrition in patients with hepatocellular injury: Three cases reports

BACKGROUND Glucose imbalance is common in total parenteral nutrition(TPN).Hypoglycemia seems to be less frequent than hyperglycemia,but it influences the clinical outcome to a greater extent.Therefore,it should be effectively prevented and treated.However,there is no relevant report on how to treat hypoglycemia caused by TPN in patients with liver cell injury.CASE SUMMARY We present three patients with liver cell injury who developed severe hypo-glycemia during or after TPN infusion.The causes of severe hypoglycemia and glucose-raising strategies were discussed.According to the physiological charac-teristics of the hepatocellular injury,the ratio of nutrition components prescribed in TPN was appropriately adjusted for the three cases.We simultaneously reduced the dose of insulin and fat emulsion,and increased the dose of glucose in TPN.The blood glucose level was restored to normal range and clinical symptoms were eliminated.CONCLUSION When hypoglycemia occurs during or after TPN in patients with hepatocellular injury,physicians need to simultaneously reduce insulin and fat emulsion,and increase glucose,and correct severe hypoglycemia in time to reduce its adverse consequences.

Analysis of Factors Associated with the Abandonment of Nutritional Recovery among Parents of Severely Malnourished Children Aged 6 to 59 Months in the Health District of Titao, Burkina Faso

Introduction: In Burkina Faso, undernutrition is a public health problem associated with more than 40% of infant and child mortality. Undernutrition management is complex, and there is often a risk of treatment abandonment. Studies on this topic have not explored the influence of environmental and therapeutic factors on parental compliance. This study proposes an analysis of factors influencing the abandonment of nutritional recovery by parents of malnourished children aged 6 to 59 months in ambulatory care. Methods: This was a descriptive and exploratory qualitative study. Data collection took place in February 2020. Data were collected from seventeen (17) participants via in-depth interviews (IDI) and direct observation. The IDIs were transcribed verbatim and thematically analyzed using Nvivo software. Results: The results revealed that factors related to the physical environment, such as geographical inaccessibility, pastoral occupation, displacement at auriferous sites, and insecurity, are important causes of nutritional recovery abandonment. They also prove that factors related to the social environment, such as lack of family and social support, feelings of shame, stigmatization, occupation of the mother, and social events, lead to this abandonment. In addition, therapeutic factors such as interruptions of supplies of Ready to Use Therapeutic Food (RUTF), feeling of improvement or worsening of the state of health, recourse to traditional medicine, and ignorance of undernutrition are also associated with this issue. Conclusion: This study highlighted barriers to the abandonment of nutritional recovery among parents of severely malnourished children aged 6 to 59 months in the health district of Titao, Burkina Faso. It is more important to consider these different factors when evaluating care protocols so that policies to reduce child undernutrition can considerably impact the targets.

Uncertainty and sensitivity analysis of in-vessel phenomena under severe accident mitigation strategy based on ISAA-SAUP program

The phenomenology involved in severe accidents in nuclear reactors is highly complex.Currently,integrated analysis programs used for severe accident analysis heavily rely on custom empirical parameters,which introduce considerable uncertainty.Therefore,in recent years,the field of severe accidents has shifted its focus toward applying uncertainty analysis methods to quantify uncertainty in safety assessment programs,known as“best estimate plus uncertainty(BEPU).”This approach aids in enhancing our comprehension of these programs and their further development and improvement.This study concentrates on a third-generation pressurized water reactor equipped with advanced active and passive mitigation strategies.Through an Integrated Severe Accident Analysis Program(ISAA),numerical modeling and uncertainty analysis were conducted on severe accidents resulting from large break loss of coolant accidents.Seventeen uncertainty parameters of the ISAA program were meticulously screened.Using Wilks'formula,the developed uncertainty program code,SAUP,was employed to carry out Latin hypercube sampling,while ISAA was employed to execute batch calculations.Statistical analysis was then conducted on two figures of merit,namely hydrogen generation and the release of fission products within the pressure vessel.Uncertainty calculations revealed that hydrogen production and the fraction of fission product released exhibited a normal distribution,ranging from 182.784 to 330.664 kg and from 15.6 to 84.3%,respectively.The ratio of hydrogen production to reactor thermal power fell within the range of 0.0578–0.105.A sensitivity analysis was performed for uncertain input parameters,revealing significant correlations between the failure temperature of the cladding oxide layer,maximum melt flow rate,size of the particulate debris,and porosity of the debris with both hydrogen generation and the release of fission products.

Accidental placement of venous return catheter in the superior vena cava during venovenous extracorporeal membrane oxygenation for severe pneumonia: A case report

BACKGROUND Venovenous extracorporeal membrane oxygenation(V-V ECMO)has become an important treatment for severe pneumonia,but there are various complications during the treatment.This article describes a case with severe pneumonia success-fully treated by V-V ECMO,but during treatment,the retrovenous catheter,which was supposed to be in the right internal vein,entered the superior vena cava directly in the mediastinum.The ECMO was safely withdrawn after multidiscip-linary consultation.Our experience with this case is expected to provide a reference for colleagues who will encounter similar situations.CASE SUMMARY A 64-year-old man had severe pulmonary infection and respiratory failure.He was admitted to our hospital and was given ventilation support(fraction of inspired oxygen 100%).The respiratory failure was not improved and he was treated by V-V ECMO,during which the venous return catheter,which was supposed to be in the right internal vein,entered the superior vena cava directly in the mediastinum.There was a risk of massive mediastinal bleeding if the catheter was removed directly when the ECMO was withdrawn.Finally,the patient underwent vena cava angiography+balloon attachment+ECMO with-drawal in the operating room(prepared for conversion to thoracotomy for vascular exploration and repair at any time during surgery)after multidiscip-linary consultation.ECMO was safely withdrawn,and the patient recovered and was discharged.CONCLUSION Patients may have different vascular conditions.Multidisciplinary cooperation can ensure patient safety.Our experience will provide a reference for similar cases.

Conceptual Strategy for Mitigating the Risk of Hydrogen as an Internal Hazard in Case of Severe Accidents at Nuclear Power Plant Considering Existing Risks and Uncertainties Associated with the Use of Traditional Strategies

Hydrogen challenge mitigation stands as one of the main objectives in the management of severe accidents at Nuclear Power Plants (NPPs). Key strategies for hydrogen control include atmospheric inertization and hydrogen removal with Passive Autocatalytic Recombiners (PARs) being a commonly accepted approach. However, an examination of PAR operation specificity reveals potential inefficiencies and reliability issues in certain severe accident scenarios. Moreover, during the in-vessel stage of severe accident development, in some severe accident scenarios PARs can unexpectedly become a source of hydrogen detonation. The effectiveness of hydrogen removal systems depends on various factors, including the chosen strategies, severe accident scenarios, reactor building design, and other influencing factors. Consequently, a comprehensive hydrogen mitigation strategy must effectively incorporate a combination of strategies rather than be based on one strategy, taking into consideration the probabilistic risks and uncertainties associated with the implementation of PARs or other traditional methods. In response to these considerations, within the framework of this research it has been suggested a conceptual strategy to mitigate the hydrogen challenge during the in-vessel stage of severe accident development.