<div style="text-align:justify;"> With the high speed development of information technology, contemporary data from a variety of fields becomes extremely large. The number of features in many datasets ...<div style="text-align:justify;"> With the high speed development of information technology, contemporary data from a variety of fields becomes extremely large. The number of features in many datasets is well above the sample size and is called high dimensional data. In statistics, variable selection approaches are required to extract the efficacious information from high dimensional data. The most popular approach is to add a penalty function coupled with a tuning parameter to the log likelihood function, which is called penalized likelihood method. However, almost all of penalized likelihood approaches only consider noise accumulation and supurious correlation whereas ignoring the endogeneity which also appeared frequently in high dimensional space. In this paper, we explore the cause of endogeneity and its influence on penalized likelihood approaches. Simulations based on five classical pe-nalized approaches are provided to vindicate their inconsistency under endogeneity. The results show that the positive selection rate of all five approaches increased gradually but the false selection rate does not consistently decrease when endogenous variables exist, that is, they do not satisfy the selection consistency. </div>展开更多
This paper investigates the effectiveness of online reviews on addressing price endogeneity issue in an application to consumer demand for smartphone.We consider review variables as the substitutes of unobserved produ...This paper investigates the effectiveness of online reviews on addressing price endogeneity issue in an application to consumer demand for smartphone.We consider review variables as the substitutes of unobserved product quality in terms of a scalar variable as seen in previous methods.An aspect-based sentiment classification technique is designed to construct feature-related review variables from millions of review contents.We discuss the performance of review variables both in a hedonic pricing model and a conditional logit discrete choice model.Our results demonstrate that review variables show a good performance either as instruments for price or as explicit control variables in demand models.In detail,the pricing prediction accuracy increases 3.4%,which is considered as a significant improvement in the practice of forecasting.In the discrete choice model,the estimated price coefficient is biased in the positive direction without endogeneity correction.It is adjusted in the expected way after including review variables.The findings indicate that online reviews provide alternative sources of information in dealing with endogeneity in discrete choice models.We also analyze the differences in the preferences and needs of individual consumers to provide some practical implications of marketing.展开更多
This paper studies the endogeneity of WTO dummy variable in the gravity model about the trade in the region of China and ASEAN. We first present a two-stage test approach for the endogeneity of WTO dummy, then transfo...This paper studies the endogeneity of WTO dummy variable in the gravity model about the trade in the region of China and ASEAN. We first present a two-stage test approach for the endogeneity of WTO dummy, then transform the endogeneity problem to a simultaneous system about WTO and trade, and construct an MLE estimation approach to the simultaneous model. The estimate of the coefficient of WTO dummy is positive, as opposed to the negative sign in the exogeneity case. From the estimation of the endogenous model, WTO has creation fold effect and strong trade diversion effect on export model in the region.展开更多
The traffic flow pertinent modelling is essential for distinct strategy formulations.However,the present literature illustrated some needed improvements for such models,especially those related to lane-specific flow.G...The traffic flow pertinent modelling is essential for distinct strategy formulations.However,the present literature illustrated some needed improvements for such models,especially those related to lane-specific flow.Given such context,this study aims to bridge the research gap by generating regression models to investigate influential factors for traffic flow based on the data collected from one multilane freeway.With the Full Bayesian specification,the hierarchical models were built by accounting for three types of random effects:the structured and unstructured spatial effects,and the one addressing the multivariate heterogeneity across multiple lanes.The endogenous relationship of traffic flow of adjacent lanes was also explored by utilizing the capability of multivariate correlation structure for simultaneous estimation of lane flow.The model estimates revealed the presence of endogeneity with statistical significance for the flow of neighbouring lanes for both directions of travel.The impact of flow was not only limited to the adjacent lanes but also to non-adjacent lanes.The multivariate specification also confirmed interdependency for lane flows.Compared to conventional approaches,the more accurate model estimation in the study indicates the advantage of incorporating the various correlation structures in the models.展开更多
The enormous advantages of active transportation lead the transportation research focus towards enhancing the walking and biking trips.The present study explored the influential factors to the walking and biking trave...The enormous advantages of active transportation lead the transportation research focus towards enhancing the walking and biking trips.The present study explored the influential factors to the walking and biking travel frequency based on data obtained from the National Household Travel Survey California add-on survey.The study features some highlights.First,bivariate models were used to account for the common unobserved heterogeneity shared at both household and personal levels.Second,endogeneity was explicitly considered.Third,both variable importance ranking and correlation analysis are employed to determine the different features to be fed into each of the joint models.The results illustrated that the models developed with endogeneity performed better than the models without endogeneity.Four influential variables which includes mode to work by bicycle,public transit usage,count of household members,and multiple race responses,tend to have statistically significant impacts on walking and biking trips.展开更多
This paper studies variable selection problem in structural equation of a two-stage least squares （2SLS） model in presence of endogeneity which is commonly encountered in empirical economic studies. Model uncertaint...This paper studies variable selection problem in structural equation of a two-stage least squares （2SLS） model in presence of endogeneity which is commonly encountered in empirical economic studies. Model uncertainty and variable selection in the structural equation is an important issue as described in Andrews and Lu （2001） and Caner （2009）. The authors propose an adaptive Lasso 2SLS estimator for linear structural equation with endogeneity and show that it enjoys the oracle properties, i.e., the consistency in both estimation and model selection. In Monte Carlo simulations, the authors demonstrate that the proposed estimator has smaller bias and MSE compared with the bridge-type GMM estimator （Caner, 2009）. In a case study, the authors revisit the classic returns to education problem （Angrist and Krueger, 1991） using the China Population census data. The authors find that the education level not only has strong effects on income but also shows heterogeneity in different age cohorts.展开更多
The research,fabrication and development of piezoelectric nanofibrous materials offer effective solutions to the challenges related to energy consumption and non-renewable resources.However,enhancing their electrical ...The research,fabrication and development of piezoelectric nanofibrous materials offer effective solutions to the challenges related to energy consumption and non-renewable resources.However,enhancing their electrical output still remains a significant challenge.Here,a strategy of inducing constrained phase separation on single nanofibers via shear force was proposed.Employing electrospinning technology,a polyacrylonitrile/polyvinylidene difluoride(PAN/PVDF)nanofibrous membrane was fabricated in one step,which enabled simultaneous piezoelectric and triboelectric conversion within a single-layer membrane.Each nanofiber contained independent components of PAN and PVDF and exhibited a rough surface.The abundant frictional contact points formed between these heterogeneous components contributed to an enhanced endogenous triboelectric output,showcasing an excellent synergistic effect of piezoelectric and triboelectric response in the nanofibrous membrane.Additionally,the component mass ratio influenced the microstructure,piezoelectric conformation and piezoelectric performance of the PAN/PVDF nanofibrous membranes.Through comprehensive performance comparison,the optimal mass ratio of PAN to PVDF was determined to be 9∶1.The piezoelectric devices made of the optimal PAN/PVDF nanofibrous membranes with rough nanofiber surfaces generated an output voltage of 20 V,which was about 1.8 times that of the smooth one at the same component mass ratio.The strategy of constrained phase separation on the surface of individual nanofibers provides a new approach to enhance the output performance of single-layer piezoelectric nanofibrous materials.展开更多
Ship outfitting is a key process in shipbuilding.Efficient and high-quality ship outfitting is a top priority for modern shipyards.These activities are conducted at different stations of shipyards.The outfitting plan ...Ship outfitting is a key process in shipbuilding.Efficient and high-quality ship outfitting is a top priority for modern shipyards.These activities are conducted at different stations of shipyards.The outfitting plan is one of the crucial issues in shipbuilding.In this paper,production scheduling and material ordering with endogenous uncertainty of the outfitting process are investigated.The uncertain factors in outfitting equipment production are usually decision-related,which leads to difficulties in addressing uncertainties in the outfitting production workshops before production is conducted according to plan.This uncertainty is regarded as endogenous uncertainty and can be treated as non-anticipativity constraints in the model.To address this problem,a stochastic two-stage programming model with endogenous uncertainty is established to optimize the outfitting job scheduling and raw material ordering process.A practical case of the shipyard of China Merchants Heavy Industry Co.,Ltd.is used to evaluate the performance of the proposed method.Satisfactory results are achieved at the lowest expected total cost as the complete kit rate of outfitting equipment is improved and emergency replenishment is reduced.展开更多
Introduction to human endogenous retrovirus type-W(HERV-W): Genomic inheritance from the past includes retroviral sequences that have been stably incorporated into our genomes and account for up to 8% of human DNA.
We previously demonstrated that inhibiting neural stem cells necroptosis enhances functional recovery after spinal cord injury.While exosomes are recognized as playing a pivotal role in neural stem cells exocrine func...We previously demonstrated that inhibiting neural stem cells necroptosis enhances functional recovery after spinal cord injury.While exosomes are recognized as playing a pivotal role in neural stem cells exocrine function,their precise function in spinal cord injury remains unclear.To investigate the role of exosomes generated following neural stem cells necroptosis after spinal cord injury,we conducted singlecell RNA sequencing and validated that neural stem cells originate from ependymal cells and undergo necroptosis in response to spinal cord injury.Subsequently,we established an in vitro necroptosis model using neural stem cells isolated from embryonic mice aged 16-17 days and extracted exosomes.The results showed that necroptosis did not significantly impact the fundamental characteristics or number of exosomes.Transcriptome sequencing of exosomes in necroptosis group identified 108 differentially expressed messenger RNAs,104 long non-coding RNAs,720 circular RNAs,and 14 microRNAs compared with the control group.Construction of a competing endogenous RNA network identified the following hub genes:tuberous sclerosis 2(Tsc2),solute carrier family 16 member 3(Slc16a3),and forkhead box protein P1(Foxp1).Notably,a significant elevation in TSC2 expression was observed in spinal cord tissues following spinal cord injury.TSC2-positive cells were localized around SRY-box transcription factor 2-positive cells within the injury zone.Furthermore,in vitro analysis revealed increased TSC2 expression in exosomal receptor cells compared with other cells.Further assessment of cellular communication following spinal cord injury showed that Tsc2 was involved in ependymal cellular communication at 1 and 3 days post-injury through the epidermal growth factor and midkine signaling pathways.In addition,Slc16a3 participated in cellular communication in ependymal cells at 7 days post-injury via the vascular endothelial growth factor and macrophage migration inhibitory factor signaling pathways.Collectively,these findings confirm that exosomes derived from neural stem cells undergoing necroptosis play an important role in cellular communication after spinal cord injury and induce TSC2 upregulation in recipient cells.展开更多
In this paper,we propose a state-varying endogenous regime switching model(the SERS model),which includes the endogenous regime switching model by Chang et al.,the CCP model,as a special case.To estimate the unknown p...In this paper,we propose a state-varying endogenous regime switching model(the SERS model),which includes the endogenous regime switching model by Chang et al.,the CCP model,as a special case.To estimate the unknown parameters in the SERS model,we propose a maximum likelihood estimation method.Monte Carlo simulation results show that in the absence of state-varying endogeneity,the SERS model and the CCP model perform similarly,while in the presence of state-varying endogeneity,the SERS model performs much better than the CCP model.Finally,we use the SERS model to analyze Chinese stock market returns,and our empirical results show that there exists strongly state-varying endogeneity in volatility switching for the Shanghai Composite Index returns.Moreover,the SERS model can indeed produce a much more realistic assessment for the regime switching process than the one obtained by the CCP model.展开更多
The presence of endogenous neural stem/progenitor cells in the adult mammalian brain suggests that the central nervous system can be repaired and regenerated after injury.However,whether it is possible to stimulate ne...The presence of endogenous neural stem/progenitor cells in the adult mammalian brain suggests that the central nervous system can be repaired and regenerated after injury.However,whether it is possible to stimulate neurogenesis and reconstruct cortical layers II to VI in non-neurogenic regions,such as the cortex,remains unknown.In this study,we implanted a hyaluronic acid collagen gel loaded with basic fibroblast growth factor into the motor cortex immediately following traumatic injury.Our findings reveal that this gel effectively stimulated the proliferation and migration of endogenous neural stem/progenitor cells,as well as their differentiation into mature and functionally integrated neurons.Importantly,these new neurons reconstructed the architecture of cortical layers II to VI,integrated into the existing neural circuitry,and ultimately led to improved brain function.These findings offer novel insight into potential clinical treatments for traumatic cerebral cortex injuries.展开更多
There are two formation routes of dietary N-nitrosamines:exogenous and endogenous formation.The formation of N-nitrosamines from either source requires precursors with a dialkylamine functional group and a nitrosating...There are two formation routes of dietary N-nitrosamines:exogenous and endogenous formation.The formation of N-nitrosamines from either source requires precursors with a dialkylamine functional group and a nitrosating agent.Precursors are supplied primarily by amine-rich foods and nitrosating agents are nitrite or its reaction products(N_(2)O_(3) and NO^(+)).Unprocessed fresh foods initially contain zero or only trace amounts of N-nitrosamines while significant amounts of N-nitrosamines can be generated during certain types of food processing.Cooking methods,pH,additives,and storage conditions can affect the formation of N-nitrosamines in foods.We analysed the formation mechanisms/pathways of the three most frequently detected N-nitrosamines in processed meats.Formation of endogenous N-nitrosamines is likely to be greater than that of exogenous N-nitrosamines.Nitrosating agents involved in the formation of endogenous N-nitrosamines are formed from nitrate in vegetables via the nitrate-nitrite-NO cycle.N-nitrosamines are produced in the human stomach and intestine but their formation mechanisms differ.We analysed the mechanism/pathway for the formation of N-nitrosotryptophan from tryptophan in the stomach.The formation of N-nitrosamines in the intestine includes both chemical and microbiological mechanisms.In addition to N-nitrosation,S-nitrosation also occurs in the human body.There is a competitive relationship between the two reactions,and S-nitrosation is more likely to occur in the healthy human body.This paper reviews the mechanisms and factors influencing the formation of exogenous and endogenous dietary N-nitrosamines,which illustrate the importance of microbial-mediated N-nitrosamine formation and the production of endogenous N-nitrosamines.展开更多
Drought is one of the important stress factors affecting the growth and development processes of wheat in China's arid zones, which severely limits the yield. This study examined the impact of deficit irrigation o...Drought is one of the important stress factors affecting the growth and development processes of wheat in China's arid zones, which severely limits the yield. This study examined the impact of deficit irrigation on the flag leaf protection system and yield of drip-irrigated spring wheat during the growth stages in arid zones. In addition, this study aimed to determine the optimal water supply mode for efficient production under drip irrigation conditions and to provide technical support for water-saving and high-yield cultivation of drip-irrigated wheat. The experiment was conducted with a split plot design using the water-sensitive variety Xinchun 22(XC22) and the drought-tolerant variety Xinchun 6(XC6) as the main plots, while a fully irrigated control(CK, 75–80% FC, where FC is field water holding capacity), mild deficit(T1, 60–65% FC) and moderate deficit(T2, 45–50% FC) at the tillering stage, and mild deficit(J1, 60–65% FC) and moderate deficit(J2, 45–50% FC) at the jointing stage were used as the subplots. Systematic studies were conducted on the regulatory effects of deficit irrigation during the tillering and jointing stages on protective substances, membrane lipid metabolism, endogenous hormones in the flag leaf, and yield of spring wheat. Compared with treatments T2 and J2, treatments T1 and J1 were beneficial for increasing the activities of superoxide dismutase(SOD), peroxidase(POD), and catalase(CAT), the levels of proline(Pro), indole-3-acetic acid(IAA), and zeatin riboside(ZR), and the ratios IAA/abscisic acid(ABA), ZR/ABA, IAA/ZR, and(IAA+ZR)/ABA, while reducing the levels of hydrogen peroxide(H2O2), superoxide anion radicals(O2–·), malondialdehyde(MDA), phosphatidic acid(PA), free fatty acids(FFA), ABA, phospholipase D(PLD), and lipoxygenase(LOX), alleviating flag leaf senescence, and increasing yield. Under treatment T1, the SOD, POD, CAT, and Pro levels of flag leaves in XC6 were 11.14, 8.08, 12.98, and 3.66% higher than those of treatment CK, and under treatment J1, they were 6.43, 4.49, 7.36, and 2.50% higher than those of treatment CK. Under treatment T1 in XC6, the IAA, ZR level of the flag leaf, spike number, grains per spike, 1,000-grain weight and yield were 10.50, 5.79, 3.10, 8.84, 3.78, and 10.52% higher than those of treatment CK, and under treatment J1, they were 5.36, 3.94, 2.40, 3.72, 1.37, and 4.46% higher than those of treatment CK. Compared with XC22, XC6 was more conducive to the improvement of flag leaf protective substances, IAA, ZR, dry matter weight, yield components and yield. The correlation analysis showed significant positive correlations between IAA and ZR with SOD, POD, CAT, proline, and yield. IAA and ZR promoted the enhancement of protective enzyme activities, thereby clearing reactive oxygen species to cope with the oxidative stress caused by drought and achieve the effect of delaying senescence. Principal component analysis showed that yield components and dry matter weight, had direct effects on yield. Mild deficiency during the tillering stage without water stress in other stages could effectively optimize yield components, not only achieving high yield while increasing protective substances, but also reducing the reactive oxygen species content. This strategy can be recommended as a water-saving and high-yield production mode for drip irrigation of spring wheat in Xinjiang, China.展开更多
Phosphorus(P)is the main limiting factor in eutrophication.Sediment P can be released decades after its accumulation.Lake restoration requires the reduction of internal sediment P loading.Although we tried to provide ...Phosphorus(P)is the main limiting factor in eutrophication.Sediment P can be released decades after its accumulation.Lake restoration requires the reduction of internal sediment P loading.Although we tried to provide a comprehensive summary of the state-of-the-art sediment P control technologies,our analyses in this review are focused on the mechanisms,control effects,and application conditions of different in-situ technologies including physical control,chemical control,ecological remediation,and combined control technology.The design principles,feasibility,operation parameters,and pros&cons of these technologies are analyzed and compared.More efforts are needed to improve in-situ sediment P control technologies so as to enhance the interaction between materials and plant communities and promote the adsorption and fixation of active P in sediments.The control materials for internal sediment P loading need to be further studied in terms of their functional properties,pre-evaluation of the P control effect,and engineering applications.展开更多
BACKGROUND Insulin therapy plays a crucial role in managing diabetes.Regulatory guidelines mandate assessing the pharmacokinetics(PK)and pharmacodynamics(PD)of new insulin formulations with euglycemic clamp techniques...BACKGROUND Insulin therapy plays a crucial role in managing diabetes.Regulatory guidelines mandate assessing the pharmacokinetics(PK)and pharmacodynamics(PD)of new insulin formulations with euglycemic clamp techniques before entry into the market.Typically,blood glucose(BG)levels are maintained at 5%below baseline to suppress endogenous insulin secretion in healthy volunteers.However,in scenarios where BG baseline is relatively low,maintaining it at 5%below baseline can increase hypoglycemic risk.Consequently,we adjusted to maintain it at 2.5%below a baseline of<4.00 mmol/L.It remains uncertain whether this adjustment impacts endogenous insulin inhibition or the PD of study insulin.AIM To evaluate and compare the PD and C-peptide status using two different target BG setting methods.METHODS Data came from euglycemic clamp trials assessing the PK/PD of insulin aspart(IAsp)in healthy participants.Target BG was set at 2.5%below baseline for those with a basal BG of<4.00 mmol/L(group A),and at 5%below baseline for others(group B).The area under the curve(AUC)of IAsp(AUC_(IAsp,0-8 h))and GIR from 0 to 8 hours(AUCGIR,0-8 h)was used to characterize the PK and PD of IAsp,respectively.The C-peptide reduction and PK/PD of IAsp were compared between the two groups.RESULTS Out of 135 subjects,15 were assigned to group A and 120 to group B;however,group B exhibited higher basal Cpeptide(1.59±0.36 vs 1.32±0.42 ng/mL,P=0.006).Following propensity score matching to adjust for basal Cpeptide differences,71 subjects(15 in group A and 56 in group B)were analyzed.No significant differences were observed in demographics,IAsp dosage,or clamp quality.Group B showed significantly higher baseline(4.35±0.21 vs 3.91±0.09 mmol/L,P<0.001),target(4.13±0.20 vs 3.81±0.08 mmol/L,P<0.001),and clamped(4.10±0.17 vs 3.80±0.06 mmol/L,P<0.001)BG levels.Both groups exhibited comparable C-peptide suppression(32.5%±10.0%vs 35.6%±12.1%,P=0.370)and similar IAsp activity(AUCGIR,0-8 h:1433±400 vs 1440±397 mg/kg,P=0.952)under nearly equivalent IAsp exposure(AUC_(IAsp,0-8 h):566±51 vs 571±85 ng/mL×h,P=0.840).CONCLUSION Maintaining BG at 2.5%below a baseline of<4.00 mmol/L did not compromise the endogenous insulin suppression nor alter the observed pharmacodynamic effects of the study insulin.展开更多
Ferroptosis is a newly proposed type of programmed cell death,which has been associated with a variety of diseases including tumors.Researchers have thereby presented nanoplatforms to mediate ferroptosis for anti-canc...Ferroptosis is a newly proposed type of programmed cell death,which has been associated with a variety of diseases including tumors.Researchers have thereby presented nanoplatforms to mediate ferroptosis for anti-cancer therapy.However,the development of ferroptosis-based nanotherapeutics is generally hindered by the limited penetration depth in tumors,poor active pharmaceutical ingredient(API)loading content and the systemic toxicity.Herein,self-propelled ferroptosis nanoinducers composed of two endogenous proteins,glucose oxidase and ferritin,are presented to show enhanced tumor inhibition via ferroptosis while maintaining high API and biocompatibility.The accumulation of our proteomotors at tumor regions is facilitated by the active tumor-targeting effect of ferritin.The enhanced diffusion of proteomotors is then actuated by efficiently decomposing glucose into gluconic acid and H_(2)O_(2),leading to deeper penetration and enhanced uptake into tumors.Under the synergistic effect of glucose oxidase and ferritin,the equilibrium between reactive oxygen species and GSH is damaged,leading to lipid peroxidation.As a result,by inducing ferroptosis,our self-propelled ferroptosis nanoinducers exhibit enhanced tumor inhibitory effects.This work paves a way for the construction of a biocompatible anticancer platform with enhanced diffusion utilizing only two endogenous proteins,centered around the concept of ferroptosis.展开更多
The 5G-R network is on the verge of entering the construction stage.Given that the dedicated network for railways is closely linked to train operation safety,there are extremely high requirements for network security....The 5G-R network is on the verge of entering the construction stage.Given that the dedicated network for railways is closely linked to train operation safety,there are extremely high requirements for network security.As a result,there is an urgent need to conduct research on 5G-R network security.To comprehensively enhance the end-to-end security protection of the 5G-R network,this study summarized the security requirements of the GSM-R network,analyzed the security risks and requirements faced by the 5G-R network,and proposed an overall 5G-R network security architecture.The security technical schemes were detailed from various aspects:5G-R infrastructure security,terminal access security,networking security,operation and maintenance security,data security,and network boundary security.Additionally,the study proposed leveraging the 5G-R security situation awareness system to achieve a comprehensive upgrade from basic security technologies to endogenous security capabilities within the 5G-R system.展开更多
Software-Defined Perimeter(SDP)provides a logical perimeter to restrict access to services.However,due to the security vulnerability of a single controller and the programmability lack of a gateway,existing SDP is fac...Software-Defined Perimeter(SDP)provides a logical perimeter to restrict access to services.However,due to the security vulnerability of a single controller and the programmability lack of a gateway,existing SDP is facing challenges.To solve the above problems,we propose a flexible and secure SDP mechanism named Mimic SDP(MSDP).MSDP consists of endogenous secure controllers and a dynamic gateway.The controllers avoid single point failure by heterogeneity and redundancy.And the dynamic gateway realizes flexible forwarding in programmable data plane by changing the processing of packet construction and deconstruction,thereby confusing the potential adversary.Besides,we propose a Markov model to evaluate the security of our SDP framework.We implement a prototype of MSDP and evaluate it in terms of functionality,performance,and scalability in different groups of systems and languages.Evaluation results demonstrate that MSDP can provide a secure connection of 93.38%with a cost of 6.34%under reasonable configuration.展开更多
AIM:To report the demographic and systemic characteristics of patients,clinical progression of endophthalmitis,and the efficacy of various treatment strategies,with a focus on identifying key factors for preserving vi...AIM:To report the demographic and systemic characteristics of patients,clinical progression of endophthalmitis,and the efficacy of various treatment strategies,with a focus on identifying key factors for preserving vision in eyes with endogenous endophthalmitis due to Klebsiella pneumoniae(K.pneumoniae)liver abscess.METHODS:In this single-center,retrospective case series of 18 patients with endogenous endophthalmitis due to K.pneumoniae liver abscess were analyzed.Ophthalmologic features of endophthalmitis at early,intermediate and advanced stages were obtained from eyes with endophthalmitis of different severities.Prompt vitrectomy was considered primarily for all eyes except for very early endophthalmitis.Intravitreal injections of antibiotics were performed in eyes with endophthalmitis in the very early stages and in eyes where vitrectomy was not available,and additional control of infection was needed after vitrectomy.Evisceration was performed in eyes with corneoscleral perforation,advanced endophthalmitis,perforation with preseptal or orbital cellulitis,uncontrolled infection,or severe pain with no vision.RESULTS:Mean(±standard deviation)age of the 18 patients with endophthalmitis was 64.5±12.2(range:32-84)y,and 14 patients(77.8%)were males.Endophthalmitis tended to involve the retinal parenchyma first and then progressed into the vitreous cavity and anterior segments.However,it presented a tendency to cause massive subretinal abscesses even after vitrectomy with silicone oil tamponade.Very high intraocular pressure with new vessels on the iris(41.7%)were also commonly observed.Although all but three patients had systemic disease such as diabetes or hypertension,visual prognosis after treatment did not appear to depend significantly on underlying comorbidities.A final best-corrected visual acuity better than 20/60 was achieved only when lesions were detected very early,with relatively good initial visual acuity,likely reflecting lower bacterial inoculation in the eye.CONCLUSION:Detection of early endophthalmitis lesions appears to be the only way to preserve good vision in patients with K.pneumoniae liver abscesses.Therefore,proper guidelines for ophthalmologic screening remain to be established for subjects at a high risk of endophthalmitis.展开更多
文摘<div style="text-align:justify;"> With the high speed development of information technology, contemporary data from a variety of fields becomes extremely large. The number of features in many datasets is well above the sample size and is called high dimensional data. In statistics, variable selection approaches are required to extract the efficacious information from high dimensional data. The most popular approach is to add a penalty function coupled with a tuning parameter to the log likelihood function, which is called penalized likelihood method. However, almost all of penalized likelihood approaches only consider noise accumulation and supurious correlation whereas ignoring the endogeneity which also appeared frequently in high dimensional space. In this paper, we explore the cause of endogeneity and its influence on penalized likelihood approaches. Simulations based on five classical pe-nalized approaches are provided to vindicate their inconsistency under endogeneity. The results show that the positive selection rate of all five approaches increased gradually but the false selection rate does not consistently decrease when endogenous variables exist, that is, they do not satisfy the selection consistency. </div>
文摘This paper investigates the effectiveness of online reviews on addressing price endogeneity issue in an application to consumer demand for smartphone.We consider review variables as the substitutes of unobserved product quality in terms of a scalar variable as seen in previous methods.An aspect-based sentiment classification technique is designed to construct feature-related review variables from millions of review contents.We discuss the performance of review variables both in a hedonic pricing model and a conditional logit discrete choice model.Our results demonstrate that review variables show a good performance either as instruments for price or as explicit control variables in demand models.In detail,the pricing prediction accuracy increases 3.4%,which is considered as a significant improvement in the practice of forecasting.In the discrete choice model,the estimated price coefficient is biased in the positive direction without endogeneity correction.It is adjusted in the expected way after including review variables.The findings indicate that online reviews provide alternative sources of information in dealing with endogeneity in discrete choice models.We also analyze the differences in the preferences and needs of individual consumers to provide some practical implications of marketing.
文摘This paper studies the endogeneity of WTO dummy variable in the gravity model about the trade in the region of China and ASEAN. We first present a two-stage test approach for the endogeneity of WTO dummy, then transform the endogeneity problem to a simultaneous system about WTO and trade, and construct an MLE estimation approach to the simultaneous model. The estimate of the coefficient of WTO dummy is positive, as opposed to the negative sign in the exogeneity case. From the estimation of the endogenous model, WTO has creation fold effect and strong trade diversion effect on export model in the region.
基金Support for this study was provided by California Department of Transportation(Caltrans,No.65A0705)。
文摘The traffic flow pertinent modelling is essential for distinct strategy formulations.However,the present literature illustrated some needed improvements for such models,especially those related to lane-specific flow.Given such context,this study aims to bridge the research gap by generating regression models to investigate influential factors for traffic flow based on the data collected from one multilane freeway.With the Full Bayesian specification,the hierarchical models were built by accounting for three types of random effects:the structured and unstructured spatial effects,and the one addressing the multivariate heterogeneity across multiple lanes.The endogenous relationship of traffic flow of adjacent lanes was also explored by utilizing the capability of multivariate correlation structure for simultaneous estimation of lane flow.The model estimates revealed the presence of endogeneity with statistical significance for the flow of neighbouring lanes for both directions of travel.The impact of flow was not only limited to the adjacent lanes but also to non-adjacent lanes.The multivariate specification also confirmed interdependency for lane flows.Compared to conventional approaches,the more accurate model estimation in the study indicates the advantage of incorporating the various correlation structures in the models.
文摘The enormous advantages of active transportation lead the transportation research focus towards enhancing the walking and biking trips.The present study explored the influential factors to the walking and biking travel frequency based on data obtained from the National Household Travel Survey California add-on survey.The study features some highlights.First,bivariate models were used to account for the common unobserved heterogeneity shared at both household and personal levels.Second,endogeneity was explicitly considered.Third,both variable importance ranking and correlation analysis are employed to determine the different features to be fed into each of the joint models.The results illustrated that the models developed with endogeneity performed better than the models without endogeneity.Four influential variables which includes mode to work by bicycle,public transit usage,count of household members,and multiple race responses,tend to have statistically significant impacts on walking and biking trips.
基金Fan’s research was supported by the National Natural Science Foundation of China under Grant No.71671149the Fundamental Research Funds for the Central Universities under Grant No.20720171042+1 种基金the Natural Science Foundation of Fujian Province of China under Grant No.2016J01340Zhong’s research was supported by the National Natural Science Foundation of China under Grant Nos.11671334,11301435,and 11401497
文摘This paper studies variable selection problem in structural equation of a two-stage least squares （2SLS） model in presence of endogeneity which is commonly encountered in empirical economic studies. Model uncertainty and variable selection in the structural equation is an important issue as described in Andrews and Lu （2001） and Caner （2009）. The authors propose an adaptive Lasso 2SLS estimator for linear structural equation with endogeneity and show that it enjoys the oracle properties, i.e., the consistency in both estimation and model selection. In Monte Carlo simulations, the authors demonstrate that the proposed estimator has smaller bias and MSE compared with the bridge-type GMM estimator （Caner, 2009）. In a case study, the authors revisit the classic returns to education problem （Angrist and Krueger, 1991） using the China Population census data. The authors find that the education level not only has strong effects on income but also shows heterogeneity in different age cohorts.
基金National Natural Science Foundation of China(No.52373281)National Energy-Saving and Low-Carbon Materials Production and Application Demonstration Platform Program,China(No.TC220H06N)。
文摘The research,fabrication and development of piezoelectric nanofibrous materials offer effective solutions to the challenges related to energy consumption and non-renewable resources.However,enhancing their electrical output still remains a significant challenge.Here,a strategy of inducing constrained phase separation on single nanofibers via shear force was proposed.Employing electrospinning technology,a polyacrylonitrile/polyvinylidene difluoride(PAN/PVDF)nanofibrous membrane was fabricated in one step,which enabled simultaneous piezoelectric and triboelectric conversion within a single-layer membrane.Each nanofiber contained independent components of PAN and PVDF and exhibited a rough surface.The abundant frictional contact points formed between these heterogeneous components contributed to an enhanced endogenous triboelectric output,showcasing an excellent synergistic effect of piezoelectric and triboelectric response in the nanofibrous membrane.Additionally,the component mass ratio influenced the microstructure,piezoelectric conformation and piezoelectric performance of the PAN/PVDF nanofibrous membranes.Through comprehensive performance comparison,the optimal mass ratio of PAN to PVDF was determined to be 9∶1.The piezoelectric devices made of the optimal PAN/PVDF nanofibrous membranes with rough nanofiber surfaces generated an output voltage of 20 V,which was about 1.8 times that of the smooth one at the same component mass ratio.The strategy of constrained phase separation on the surface of individual nanofibers provides a new approach to enhance the output performance of single-layer piezoelectric nanofibrous materials.
基金supported in part by the High-tech ship scientific research project of the Ministry of Industry and Information Technology of the People’s Republic of China,and the National Nature Science Foundation of China(Grant No.71671113)the Science and Technology Department of Shaanxi Province(No.2020GY-219)the Ministry of Education Collaborative Project of Production,Learning and Research(No.201901024016).
文摘Ship outfitting is a key process in shipbuilding.Efficient and high-quality ship outfitting is a top priority for modern shipyards.These activities are conducted at different stations of shipyards.The outfitting plan is one of the crucial issues in shipbuilding.In this paper,production scheduling and material ordering with endogenous uncertainty of the outfitting process are investigated.The uncertain factors in outfitting equipment production are usually decision-related,which leads to difficulties in addressing uncertainties in the outfitting production workshops before production is conducted according to plan.This uncertainty is regarded as endogenous uncertainty and can be treated as non-anticipativity constraints in the model.To address this problem,a stochastic two-stage programming model with endogenous uncertainty is established to optimize the outfitting job scheduling and raw material ordering process.A practical case of the shipyard of China Merchants Heavy Industry Co.,Ltd.is used to evaluate the performance of the proposed method.Satisfactory results are achieved at the lowest expected total cost as the complete kit rate of outfitting equipment is improved and emergency replenishment is reduced.
基金supported by the Christiane and Claudia Hempel Foundation for Regenerative Medicineby the James and Elisabeth Cloppenburg, Peek and Cloppenburg Düsseldorf Stiftung(to PK)。
文摘Introduction to human endogenous retrovirus type-W(HERV-W): Genomic inheritance from the past includes retroviral sequences that have been stably incorporated into our genomes and account for up to 8% of human DNA.
基金supported by the National Natural Science Foundation of China,No.81801907(to NC)Shenzhen Key Laboratory of Bone Tissue Repair and Translational Research,No.ZDSYS20230626091402006(to NC)+2 种基金Sanming Project of Medicine in Shenzhen,No.SZSM201911002(to SL)Foundation of Shenzhen Committee for Science and Technology Innovation,Nos.JCYJ20230807110310021(to NC),JCYJ20230807110259002(to JL)Science and Technology Program of Guangzhou,No.2024A04J4716(to TL)。
文摘We previously demonstrated that inhibiting neural stem cells necroptosis enhances functional recovery after spinal cord injury.While exosomes are recognized as playing a pivotal role in neural stem cells exocrine function,their precise function in spinal cord injury remains unclear.To investigate the role of exosomes generated following neural stem cells necroptosis after spinal cord injury,we conducted singlecell RNA sequencing and validated that neural stem cells originate from ependymal cells and undergo necroptosis in response to spinal cord injury.Subsequently,we established an in vitro necroptosis model using neural stem cells isolated from embryonic mice aged 16-17 days and extracted exosomes.The results showed that necroptosis did not significantly impact the fundamental characteristics or number of exosomes.Transcriptome sequencing of exosomes in necroptosis group identified 108 differentially expressed messenger RNAs,104 long non-coding RNAs,720 circular RNAs,and 14 microRNAs compared with the control group.Construction of a competing endogenous RNA network identified the following hub genes:tuberous sclerosis 2(Tsc2),solute carrier family 16 member 3(Slc16a3),and forkhead box protein P1(Foxp1).Notably,a significant elevation in TSC2 expression was observed in spinal cord tissues following spinal cord injury.TSC2-positive cells were localized around SRY-box transcription factor 2-positive cells within the injury zone.Furthermore,in vitro analysis revealed increased TSC2 expression in exosomal receptor cells compared with other cells.Further assessment of cellular communication following spinal cord injury showed that Tsc2 was involved in ependymal cellular communication at 1 and 3 days post-injury through the epidermal growth factor and midkine signaling pathways.In addition,Slc16a3 participated in cellular communication in ependymal cells at 7 days post-injury via the vascular endothelial growth factor and macrophage migration inhibitory factor signaling pathways.Collectively,these findings confirm that exosomes derived from neural stem cells undergoing necroptosis play an important role in cellular communication after spinal cord injury and induce TSC2 upregulation in recipient cells.
基金The authors extend their sincere thanks to the editor and two referees for their insightful comments that helped improve the article substantially.This research is supported by the National Natural Science Foundation of China(Project 71803091)by the MOE(Ministry of Education in China)Project of Humanities and Social Sciences(Project 18YJC790015).
文摘In this paper,we propose a state-varying endogenous regime switching model(the SERS model),which includes the endogenous regime switching model by Chang et al.,the CCP model,as a special case.To estimate the unknown parameters in the SERS model,we propose a maximum likelihood estimation method.Monte Carlo simulation results show that in the absence of state-varying endogeneity,the SERS model and the CCP model perform similarly,while in the presence of state-varying endogeneity,the SERS model performs much better than the CCP model.Finally,we use the SERS model to analyze Chinese stock market returns,and our empirical results show that there exists strongly state-varying endogeneity in volatility switching for the Shanghai Composite Index returns.Moreover,the SERS model can indeed produce a much more realistic assessment for the regime switching process than the one obtained by the CCP model.
基金supported by the National Natural Science Foundation of China,Nos.82272171(to ZY),82271403(to XL),81941011(to XL),31971279(to ZY),31730030(to XL)the Natural Science Foundation of Beijing,No.7222004(to HD).
文摘The presence of endogenous neural stem/progenitor cells in the adult mammalian brain suggests that the central nervous system can be repaired and regenerated after injury.However,whether it is possible to stimulate neurogenesis and reconstruct cortical layers II to VI in non-neurogenic regions,such as the cortex,remains unknown.In this study,we implanted a hyaluronic acid collagen gel loaded with basic fibroblast growth factor into the motor cortex immediately following traumatic injury.Our findings reveal that this gel effectively stimulated the proliferation and migration of endogenous neural stem/progenitor cells,as well as their differentiation into mature and functionally integrated neurons.Importantly,these new neurons reconstructed the architecture of cortical layers II to VI,integrated into the existing neural circuitry,and ultimately led to improved brain function.These findings offer novel insight into potential clinical treatments for traumatic cerebral cortex injuries.
基金supported by the National Natural Science Foundation of China(Nos.22376114 and 22076091)the State Key Joint Laboratory of Environment Simulation and Pollution Control,China(No.21L01ESPC)the Youth Science and Technology Innovation Program of Xiamen Ocean and Fisheries Development Special Funds(No.23YYST062QCB29)。
文摘There are two formation routes of dietary N-nitrosamines:exogenous and endogenous formation.The formation of N-nitrosamines from either source requires precursors with a dialkylamine functional group and a nitrosating agent.Precursors are supplied primarily by amine-rich foods and nitrosating agents are nitrite or its reaction products(N_(2)O_(3) and NO^(+)).Unprocessed fresh foods initially contain zero or only trace amounts of N-nitrosamines while significant amounts of N-nitrosamines can be generated during certain types of food processing.Cooking methods,pH,additives,and storage conditions can affect the formation of N-nitrosamines in foods.We analysed the formation mechanisms/pathways of the three most frequently detected N-nitrosamines in processed meats.Formation of endogenous N-nitrosamines is likely to be greater than that of exogenous N-nitrosamines.Nitrosating agents involved in the formation of endogenous N-nitrosamines are formed from nitrate in vegetables via the nitrate-nitrite-NO cycle.N-nitrosamines are produced in the human stomach and intestine but their formation mechanisms differ.We analysed the mechanism/pathway for the formation of N-nitrosotryptophan from tryptophan in the stomach.The formation of N-nitrosamines in the intestine includes both chemical and microbiological mechanisms.In addition to N-nitrosation,S-nitrosation also occurs in the human body.There is a competitive relationship between the two reactions,and S-nitrosation is more likely to occur in the healthy human body.This paper reviews the mechanisms and factors influencing the formation of exogenous and endogenous dietary N-nitrosamines,which illustrate the importance of microbial-mediated N-nitrosamine formation and the production of endogenous N-nitrosamines.
基金made possible by the National Natural Science Foundation of China (32060422)。
文摘Drought is one of the important stress factors affecting the growth and development processes of wheat in China's arid zones, which severely limits the yield. This study examined the impact of deficit irrigation on the flag leaf protection system and yield of drip-irrigated spring wheat during the growth stages in arid zones. In addition, this study aimed to determine the optimal water supply mode for efficient production under drip irrigation conditions and to provide technical support for water-saving and high-yield cultivation of drip-irrigated wheat. The experiment was conducted with a split plot design using the water-sensitive variety Xinchun 22(XC22) and the drought-tolerant variety Xinchun 6(XC6) as the main plots, while a fully irrigated control(CK, 75–80% FC, where FC is field water holding capacity), mild deficit(T1, 60–65% FC) and moderate deficit(T2, 45–50% FC) at the tillering stage, and mild deficit(J1, 60–65% FC) and moderate deficit(J2, 45–50% FC) at the jointing stage were used as the subplots. Systematic studies were conducted on the regulatory effects of deficit irrigation during the tillering and jointing stages on protective substances, membrane lipid metabolism, endogenous hormones in the flag leaf, and yield of spring wheat. Compared with treatments T2 and J2, treatments T1 and J1 were beneficial for increasing the activities of superoxide dismutase(SOD), peroxidase(POD), and catalase(CAT), the levels of proline(Pro), indole-3-acetic acid(IAA), and zeatin riboside(ZR), and the ratios IAA/abscisic acid(ABA), ZR/ABA, IAA/ZR, and(IAA+ZR)/ABA, while reducing the levels of hydrogen peroxide(H2O2), superoxide anion radicals(O2–·), malondialdehyde(MDA), phosphatidic acid(PA), free fatty acids(FFA), ABA, phospholipase D(PLD), and lipoxygenase(LOX), alleviating flag leaf senescence, and increasing yield. Under treatment T1, the SOD, POD, CAT, and Pro levels of flag leaves in XC6 were 11.14, 8.08, 12.98, and 3.66% higher than those of treatment CK, and under treatment J1, they were 6.43, 4.49, 7.36, and 2.50% higher than those of treatment CK. Under treatment T1 in XC6, the IAA, ZR level of the flag leaf, spike number, grains per spike, 1,000-grain weight and yield were 10.50, 5.79, 3.10, 8.84, 3.78, and 10.52% higher than those of treatment CK, and under treatment J1, they were 5.36, 3.94, 2.40, 3.72, 1.37, and 4.46% higher than those of treatment CK. Compared with XC22, XC6 was more conducive to the improvement of flag leaf protective substances, IAA, ZR, dry matter weight, yield components and yield. The correlation analysis showed significant positive correlations between IAA and ZR with SOD, POD, CAT, proline, and yield. IAA and ZR promoted the enhancement of protective enzyme activities, thereby clearing reactive oxygen species to cope with the oxidative stress caused by drought and achieve the effect of delaying senescence. Principal component analysis showed that yield components and dry matter weight, had direct effects on yield. Mild deficiency during the tillering stage without water stress in other stages could effectively optimize yield components, not only achieving high yield while increasing protective substances, but also reducing the reactive oxygen species content. This strategy can be recommended as a water-saving and high-yield production mode for drip irrigation of spring wheat in Xinjiang, China.
基金financially supported by the National Natural Science Foundation of China(Nos.32201384,31830013,U20A2010)。
文摘Phosphorus(P)is the main limiting factor in eutrophication.Sediment P can be released decades after its accumulation.Lake restoration requires the reduction of internal sediment P loading.Although we tried to provide a comprehensive summary of the state-of-the-art sediment P control technologies,our analyses in this review are focused on the mechanisms,control effects,and application conditions of different in-situ technologies including physical control,chemical control,ecological remediation,and combined control technology.The design principles,feasibility,operation parameters,and pros&cons of these technologies are analyzed and compared.More efforts are needed to improve in-situ sediment P control technologies so as to enhance the interaction between materials and plant communities and promote the adsorption and fixation of active P in sediments.The control materials for internal sediment P loading need to be further studied in terms of their functional properties,pre-evaluation of the P control effect,and engineering applications.
基金This retrospective analysis incorporated data from two clinical trials(CTR20220854 and CTR20222843)sponsored by Chongqing Chenan Biopharmaceutical Co.,Ltd.and Jiangsu Hengrui Pharmaceuticals Co.,Ltd.However,these sponsors did not partake in the study design,data interpretation,or manuscript preparation.
文摘BACKGROUND Insulin therapy plays a crucial role in managing diabetes.Regulatory guidelines mandate assessing the pharmacokinetics(PK)and pharmacodynamics(PD)of new insulin formulations with euglycemic clamp techniques before entry into the market.Typically,blood glucose(BG)levels are maintained at 5%below baseline to suppress endogenous insulin secretion in healthy volunteers.However,in scenarios where BG baseline is relatively low,maintaining it at 5%below baseline can increase hypoglycemic risk.Consequently,we adjusted to maintain it at 2.5%below a baseline of<4.00 mmol/L.It remains uncertain whether this adjustment impacts endogenous insulin inhibition or the PD of study insulin.AIM To evaluate and compare the PD and C-peptide status using two different target BG setting methods.METHODS Data came from euglycemic clamp trials assessing the PK/PD of insulin aspart(IAsp)in healthy participants.Target BG was set at 2.5%below baseline for those with a basal BG of<4.00 mmol/L(group A),and at 5%below baseline for others(group B).The area under the curve(AUC)of IAsp(AUC_(IAsp,0-8 h))and GIR from 0 to 8 hours(AUCGIR,0-8 h)was used to characterize the PK and PD of IAsp,respectively.The C-peptide reduction and PK/PD of IAsp were compared between the two groups.RESULTS Out of 135 subjects,15 were assigned to group A and 120 to group B;however,group B exhibited higher basal Cpeptide(1.59±0.36 vs 1.32±0.42 ng/mL,P=0.006).Following propensity score matching to adjust for basal Cpeptide differences,71 subjects(15 in group A and 56 in group B)were analyzed.No significant differences were observed in demographics,IAsp dosage,or clamp quality.Group B showed significantly higher baseline(4.35±0.21 vs 3.91±0.09 mmol/L,P<0.001),target(4.13±0.20 vs 3.81±0.08 mmol/L,P<0.001),and clamped(4.10±0.17 vs 3.80±0.06 mmol/L,P<0.001)BG levels.Both groups exhibited comparable C-peptide suppression(32.5%±10.0%vs 35.6%±12.1%,P=0.370)and similar IAsp activity(AUCGIR,0-8 h:1433±400 vs 1440±397 mg/kg,P=0.952)under nearly equivalent IAsp exposure(AUC_(IAsp,0-8 h):566±51 vs 571±85 ng/mL×h,P=0.840).CONCLUSION Maintaining BG at 2.5%below a baseline of<4.00 mmol/L did not compromise the endogenous insulin suppression nor alter the observed pharmacodynamic effects of the study insulin.
基金supported by National Key Research and Development Program of China(No.2022YFA1206900)National Natural Science Foundation of China(Nos.22175083,82204415,51973241,22375224)GuangDong Basic and Applied Basic Research Foundation(No.2021A1515220187)。
文摘Ferroptosis is a newly proposed type of programmed cell death,which has been associated with a variety of diseases including tumors.Researchers have thereby presented nanoplatforms to mediate ferroptosis for anti-cancer therapy.However,the development of ferroptosis-based nanotherapeutics is generally hindered by the limited penetration depth in tumors,poor active pharmaceutical ingredient(API)loading content and the systemic toxicity.Herein,self-propelled ferroptosis nanoinducers composed of two endogenous proteins,glucose oxidase and ferritin,are presented to show enhanced tumor inhibition via ferroptosis while maintaining high API and biocompatibility.The accumulation of our proteomotors at tumor regions is facilitated by the active tumor-targeting effect of ferritin.The enhanced diffusion of proteomotors is then actuated by efficiently decomposing glucose into gluconic acid and H_(2)O_(2),leading to deeper penetration and enhanced uptake into tumors.Under the synergistic effect of glucose oxidase and ferritin,the equilibrium between reactive oxygen species and GSH is damaged,leading to lipid peroxidation.As a result,by inducing ferroptosis,our self-propelled ferroptosis nanoinducers exhibit enhanced tumor inhibitory effects.This work paves a way for the construction of a biocompatible anticancer platform with enhanced diffusion utilizing only two endogenous proteins,centered around the concept of ferroptosis.
文摘The 5G-R network is on the verge of entering the construction stage.Given that the dedicated network for railways is closely linked to train operation safety,there are extremely high requirements for network security.As a result,there is an urgent need to conduct research on 5G-R network security.To comprehensively enhance the end-to-end security protection of the 5G-R network,this study summarized the security requirements of the GSM-R network,analyzed the security risks and requirements faced by the 5G-R network,and proposed an overall 5G-R network security architecture.The security technical schemes were detailed from various aspects:5G-R infrastructure security,terminal access security,networking security,operation and maintenance security,data security,and network boundary security.Additionally,the study proposed leveraging the 5G-R security situation awareness system to achieve a comprehensive upgrade from basic security technologies to endogenous security capabilities within the 5G-R system.
基金supported by the National Key Research and Development Program of China(Grant No.2022YFB2901304)。
文摘Software-Defined Perimeter(SDP)provides a logical perimeter to restrict access to services.However,due to the security vulnerability of a single controller and the programmability lack of a gateway,existing SDP is facing challenges.To solve the above problems,we propose a flexible and secure SDP mechanism named Mimic SDP(MSDP).MSDP consists of endogenous secure controllers and a dynamic gateway.The controllers avoid single point failure by heterogeneity and redundancy.And the dynamic gateway realizes flexible forwarding in programmable data plane by changing the processing of packet construction and deconstruction,thereby confusing the potential adversary.Besides,we propose a Markov model to evaluate the security of our SDP framework.We implement a prototype of MSDP and evaluate it in terms of functionality,performance,and scalability in different groups of systems and languages.Evaluation results demonstrate that MSDP can provide a secure connection of 93.38%with a cost of 6.34%under reasonable configuration.
文摘AIM:To report the demographic and systemic characteristics of patients,clinical progression of endophthalmitis,and the efficacy of various treatment strategies,with a focus on identifying key factors for preserving vision in eyes with endogenous endophthalmitis due to Klebsiella pneumoniae(K.pneumoniae)liver abscess.METHODS:In this single-center,retrospective case series of 18 patients with endogenous endophthalmitis due to K.pneumoniae liver abscess were analyzed.Ophthalmologic features of endophthalmitis at early,intermediate and advanced stages were obtained from eyes with endophthalmitis of different severities.Prompt vitrectomy was considered primarily for all eyes except for very early endophthalmitis.Intravitreal injections of antibiotics were performed in eyes with endophthalmitis in the very early stages and in eyes where vitrectomy was not available,and additional control of infection was needed after vitrectomy.Evisceration was performed in eyes with corneoscleral perforation,advanced endophthalmitis,perforation with preseptal or orbital cellulitis,uncontrolled infection,or severe pain with no vision.RESULTS:Mean(±standard deviation)age of the 18 patients with endophthalmitis was 64.5±12.2(range:32-84)y,and 14 patients(77.8%)were males.Endophthalmitis tended to involve the retinal parenchyma first and then progressed into the vitreous cavity and anterior segments.However,it presented a tendency to cause massive subretinal abscesses even after vitrectomy with silicone oil tamponade.Very high intraocular pressure with new vessels on the iris(41.7%)were also commonly observed.Although all but three patients had systemic disease such as diabetes or hypertension,visual prognosis after treatment did not appear to depend significantly on underlying comorbidities.A final best-corrected visual acuity better than 20/60 was achieved only when lesions were detected very early,with relatively good initial visual acuity,likely reflecting lower bacterial inoculation in the eye.CONCLUSION:Detection of early endophthalmitis lesions appears to be the only way to preserve good vision in patients with K.pneumoniae liver abscesses.Therefore,proper guidelines for ophthalmologic screening remain to be established for subjects at a high risk of endophthalmitis.
