BACKGROUND Two-stage revision arthroplasty with an antibiotic-loaded spacer is the treatment of choice in chronically infected total hip arthroplasties.Interval spacers can be functional articulating or prefabricated....BACKGROUND Two-stage revision arthroplasty with an antibiotic-loaded spacer is the treatment of choice in chronically infected total hip arthroplasties.Interval spacers can be functional articulating or prefabricated.Functional results of these spacers have scarcely been reported.AIM To compare retrospectively the patient reported outcome and infection eradication rate after two-stage revision arthroplasty of the hip with the use of a functional articulating or prefabricated spacer.METHODS All patients with two-stage revision of a hip prosthesis at our hospital between 2003 and 2016 were included in this retrospective cohort study.Patients were divided into two groups;patients treated with a functional articulating spacer or with a prefabricated spacer.Patients completed the Hip Osteoarthritis Outcome Score and the EQ-5D-3L(EQ-5D)and the EQ-5D quality of life thermometer(EQVAS)scores.Primary outcomes were patient reported outcome and infection eradication after two-stage revision.The results of both groups were compared to the patient acceptable symptom state for primary arthroplasty of the hip.Secondary outcomes were complications during spacer treatment and at final follow-up.Descriptive statistics,mean and range are used to represent the demographics of the patients.For numerical variables,students’t-tests were used to assess the level of significance for differences between the groups,with 95%confidence intervals;for binary outcome,we used Fisher’s exact test.RESULTS We consecutively treated 55 patients with a prefabricated spacer and 15 patients with a functional articulating spacer of the hip.The infection eradication rates for functional articulating and prefabricated spacers were 93%and 78%,respectively(P>0.05).With respect to the functional outcome,the Hip Osteoarthritis Outcome Score(HOOS)and its subscores(all P<0.01),the EQ-5D(P<0.01)and the EQVAS scores(P<0.05)were all significantly better for patients successfully treated with a functional articulating spacer.More patients in the functional articulating spacer group reached the patient acceptable symptom state for the HOOS pain,HOOS quality of life and EQ-VAS.The number of patients with a spacer dislocation was not significantly different for the functional articulating or prefabricated spacer group(P>0.05).However,the number of dislocations per patient experiencing a dislocation was significantly higher for patients with a prefabricated spacer(P<0.01).CONCLUSION Functional articulating spacers lead to improved patient reported functional outcome and less perioperative complications after two-stage revision arthroplasty of an infected total hip prosthesis,while maintaining a similar infection eradication rate compared to prefabricated spacers.展开更多
Periprosthetic joint infection(PJI)following total knee arthroplasty is one of the most catastrophic and costly complications that carries significant patient wellness as well as economic burdens.The road to efficient...Periprosthetic joint infection(PJI)following total knee arthroplasty is one of the most catastrophic and costly complications that carries significant patient wellness as well as economic burdens.The road to efficiently diagnosing and treating PJI is challenging,as there is still no gold standard method to reach the diagnosis as early as desired.There are also international controversies with respect to the best approach to manage PJI cases.In this review,we highlight recent advances in managing PJI following knee arthroplasty surgery and discuss in depth the two-stage revision method.展开更多
BACKGROUND Periprosthetic joint infection(PJI)is a catastrophic complication that can occur following total knee arthroplasty(TKA).Currently,the treatment for PJI mainly includes the use of antibiotics alone,prostheti...BACKGROUND Periprosthetic joint infection(PJI)is a catastrophic complication that can occur following total knee arthroplasty(TKA).Currently,the treatment for PJI mainly includes the use of antibiotics alone,prosthetic debridement lavage,primary revision,secondary revision,joint fusion,amputation,etc.AIM To explore the clinical effect of two-stage revision surgery for the treatment of PJI after TKA.METHODS The clinical data of 27 patients(3 males and 24 females;age range,47–80 years;mean age,66.7±8.0 years;27 knees)with PJI treated with two-stage revision surgery in our hospital between January 1,2010 and December 31,2020 were analyzed retrospectively.The following outcomes were compared for changes between preoperative and last follow-up results:Erythrocyte sedimentation rate(ESR),C-reactive protein(CRP),visual analogue scale(VAS)scores,Hospital for Special Surgery(HSS)scores,knee range of motion(ROM),and infection cure rates.RESULTS All 27 patients were followed up(range,13–112 mo).The ESR(14.5±6.3 mm/h)and CRP(0.6±0.4 mg/dL)of the patients at the last follow-up were significantly lower than those at admission;the difference was statistically significant(P<0.001).The postoperative VAS score(1.1±0.7),HSS score(82.3±7.1),and knee ROM(108.0°±19.7°)were significantly improved compared with those before the surgery;the difference was statistically significant(P<0.001).Of the 27 patients,26 were cured of the infection,whereas 1 case had an infection recurrence;the infection control rate was 96.3%.CONCLUSION Two-stage revision surgery can effectively relieve pain,control infection,and retain good joint function in the treatment of PJI after TKA.展开更多
BACKGROUND Periprosthetic joint infections(PJIs)are frequently caused by coagulase-negative Staphylococci(CoNS),which is known to be a hard-to-treat microorganism.Antibiotic resistance among causative pathogens of PJI...BACKGROUND Periprosthetic joint infections(PJIs)are frequently caused by coagulase-negative Staphylococci(CoNS),which is known to be a hard-to-treat microorganism.Antibiotic resistance among causative pathogens of PJI is increasing.Two-stage revision is the favoured treatment for chronic CoNS infection of a hip or knee prosthesis.We hypothesised that the infection eradication rate of our treatment protocol for two-stage revision surgery for CoNS PJI of the hip and knee would be comparable to eradication rates described in the literature.AIM To evaluate the infection eradication rate of two-stage revision arthroplasty for PJI caused by CoNS.METHODS All patients treated with two-stage revision of a hip or knee prosthesis were retrospectively included.Patients with CoNS infection were included in the study,including polymicrobial cases.Primary outcome was infection eradication at final follow-up.RESULTS Forty-four patients were included in the study.Twenty-nine patients were treated for PJI of the hip and fifteen for PJI of the knee.At final follow-up after a mean of 37 mo,recurrent or persistent infection was present in eleven patients.CONCLUSION PJI with CoNS can be a difficult to treat infection due to increasing antibiotic resistance.Infection eradication rate of 70%-80%may be achieved.展开更多
BACKGROUND Two-stage revision is the most common treatment for chronic periprosthetic joint infection of the hip,involving a resection arthroplasty with or without placement of an antibiotic-loaded spacer,followed by ...BACKGROUND Two-stage revision is the most common treatment for chronic periprosthetic joint infection of the hip,involving a resection arthroplasty with or without placement of an antibiotic-loaded spacer,followed by antibiotic therapy before reimplantation.AIM To compare the outcomes and complications of two consecutive treatment protocols for two-stage revision arthroplasty of the infected hip:One using Girdlestone with an antibiotic holiday,the other using custom-made articulating spacers(CUMARS)without an antibiotic holiday.METHODS In this retrospective study,two consecutive cohorts were compared.Group A(2017-2020)underwent two-stage revision with a Girdlestone and an antibiotic holiday before reimplantation,while Group B(2020-2023)received CUMARS whenever possible,and no antibiotic holiday,or a Girdlestone if indicated.The primary outcome was successful infection eradication after one year.Secondary outcomes included surgical duration,length of hospital stay,weight-bearing allowance,discharge destination,and complications.RESULTS A total of 98 patients were included:39 patients in Group A and 59 patients in Group B.Successful infection eradication after one year was achieved in 69%of Group A and 83%of Group B(P=0.164).Patients in Group B were more frequently allowed to bear weight(64%vs 18%,P<0.001),had a shorter in-hospital stay(9 vs 16 days,P<0.001),and were more often discharged home after the first surgery(48%vs 24%,P=0.048).No significant differences were found in(mechanical)complications.CONCLUSION A protocol including CUMARS is a safe and effective treatment,offering faster recovery,shorter length of hospital stay,and enabling more patients to return home during the interval.This reduces strain on patients and the healthcare system,potentially saving costs,without compromising infection control or increasing(mechanical)complications.展开更多
A controversial taxon,Hipparion plocodus,is reviewed in the present study.Hi.plocodus has been confirmed to be a valid species with definite diagnostic characteristics,represented by cranial specimens from Baode,Shanx...A controversial taxon,Hipparion plocodus,is reviewed in the present study.Hi.plocodus has been confirmed to be a valid species with definite diagnostic characteristics,represented by cranial specimens from Baode,Shanxi Province.The phylogenetic analysis performed in the present study,with a new matrix,shows that Hi.plocodus forms a monophyletic group with a European species,Hippotherium malpassii.Actually,no close relationship between so-called Hm.malpassii and the genus Hippotherium has been identified,and the record of stratigraphic range of this genus in late stage of Late Miocene is currently absent.Herein previously Hi.plocodus and Hm.malpassii have both attributed into“Hipparion”before the discovery of better material.Evolutionary stages and correlative absolute age showed that these two species should derive independently from some primitive clade.During the late stage of the Late Miocene,the development of the Asian summer monsoon enhanced the humidity of China,with forest and wood habitats expanding considerably under this setting.As the result,one Eurasian closed-habitat lineage thus extended its range into China,which had become very suited for it,give rise to“Hi.”plocodus.展开更多
Methods to optimize the production of gamma-aminobutyric acid （GABA） by Lactobacillus brevis CGMCC 1306 were investigated. Results indicated that cell growth was maximal at pH 5.0, while pH 4.5 was pref-erable to GA...Methods to optimize the production of gamma-aminobutyric acid （GABA） by Lactobacillus brevis CGMCC 1306 were investigated. Results indicated that cell growth was maximal at pH 5.0, while pH 4.5 was pref-erable to GABA formation. The optimal temperature for cell growth （35 °C） was lower than that for GABA forma-tion （40 °C）. In a two-stage pH and temperature control fermentation, cultures were maintained at pH 5.0 and 35 °C for 32 h, then adjusted to pH 4.5 and 40 °C, GABA production increased remarkably and reached 474.79 mmol·L-1 at 72 h, while it was 398.63 mmol·L-1 with one stage pH and temperature control process, in which cultivation con-ditions were constantly controlled at pH 5.0 and 35 °C. In order to avoid the inhibition of cell growth at higher L-monosodium glutamate （L-MSG） concentrations, the two-stage control fermentation with substrate feeding strat-egy was applied to GABA production, with 106.87 mmol （20 g） L-MSG supplemented into the shaking-flask at 32 h and 56 h post-inoculation separately. The GABA concentration reached 526.33 mmol·L-1 at 72 h with the fer-mentation volume increased by 38%. These results will provide primary data to realize large-scale production of GABA by L. brevis CGMCC 1306.展开更多
A new unified constitutive model was developed to predict the two-stage creep-aging(TSCA)behavior of Al-Zn-Mg-Cu alloys.The particular bimodal precipitation feature was analyzed and modeled by considering the primary ...A new unified constitutive model was developed to predict the two-stage creep-aging(TSCA)behavior of Al-Zn-Mg-Cu alloys.The particular bimodal precipitation feature was analyzed and modeled by considering the primary micro-variables evolution at different temperatures and their interaction.The dislocation density was incorporated into the model to capture the effect of creep deformation on precipitation.Quantitative transmission electron microscopy and experimental data obtained from a previous study were used to calibrate the model.Subsequently,the developed constitutive model was implemented in the finite element(FE)software ABAQUS via the user subroutines for TSCA process simulation and the springback prediction of an integral panel.A TSCA test was performed.The result shows that the maximum radius deviation between the formed plate and the simulation results is less than 0.4 mm,thus validating the effectiveness of the developed constitutive model and FE model.展开更多
Lexical analysis is a fundamental task in natural language processing,which involves several subtasks,such as word segmentation(WS),part-of-speech(POS)tagging,and named entity recognition(NER).Recent works have shown ...Lexical analysis is a fundamental task in natural language processing,which involves several subtasks,such as word segmentation(WS),part-of-speech(POS)tagging,and named entity recognition(NER).Recent works have shown that taking advantage of relatedness between these subtasks can be beneficial.This paper proposes a unified neural framework to address these subtasks simultaneously.Apart from the sequence tagging paradigm,the proposed method tackles the multitask lexical analysis via two-stage sequence span classification.Firstly,the model detects the word and named entity boundaries by multilabel classification over character spans in a sentence.Then,the authors assign POS labels and entity labels for words and named entities by multi-class classification,respectively.Furthermore,a Gated Task Transformation(GTT)is proposed to encourage the model to share valuable features between tasks.The performance of the proposed model was evaluated on Chinese and Thai public datasets,demonstrating state-of-the-art results.展开更多
Applying bio-oxidation waste solution(BOS)to chemical-biological two-stage oxidation process can significantly improve the bio-oxidation efficiency of arsenopyrite.This study aims to clarify the enhanced oxidation mec...Applying bio-oxidation waste solution(BOS)to chemical-biological two-stage oxidation process can significantly improve the bio-oxidation efficiency of arsenopyrite.This study aims to clarify the enhanced oxidation mechanism of arsenopyrite by evaluating the effects of physical and chemical changes of arsenopyrite in BOS chemical oxidation stage on mineral dissolution kinetics,as well as microbial growth activity and community structure composition in bio-oxidation stage.The results showed that the chemical oxidation contributed to destroying the physical and chemical structure of arsenopyrite surface and reducing the particle size,and led to the formation of nitrogenous substances on mineral surface.These chemical oxidation behaviors effectively promoted Fe^(3+)cycling in the bio-oxidation system and weakened the inhibitory effect of the sulfur film on ionic diffusion,thereby enhancing the dissolution kinetics of the arsenopyrite.Therefore,the bio-oxidation efficiency of arsenopyrite was significantly increased in the two-stage oxidation process.After 18 d,the two-stage oxidation process achieved total extraction rates of(88.8±2.0)%,(86.7±1.3)%,and(74.7±3.0)%for As,Fe,and S elements,respectively.These values represented a significant increase of(50.8±3.4)%,(47.1±2.7)%,and(46.0±0.7)%,respectively,compared to the one-stage bio-oxidation process.展开更多
Exploring the factors driving the decoupling of China’s sulfur dioxide(SO_(2))emissions from economic growth(DEI)is crucial for achieving sustainable development.By analyzing the decoupling indicators and driving fac...Exploring the factors driving the decoupling of China’s sulfur dioxide(SO_(2))emissions from economic growth(DEI)is crucial for achieving sustainable development.By analyzing the decoupling indicators and driving factors at both the generation and treatment stages of SO_(2),more effective targeted mitigation strategies can be developed.We employ the Tapio decoupling model and propose a two-stage method to examine the decoupling issues related to SO_(2).Our findings indicate that:①DEI shows a steady and significant improvement,with SO_(2)emission intensity identified as the primary driver.②for the decoupling of economic growth and SO_(2)generation,energy scale serves as the largest stimulator,while the effect of energy intensity changes from negative to positive,and pollution intensity is first positive and then negative.③For the decoupling of SO_(2)generation and SO_(2)removal,treatment efficiency leads as the largest promoter,followed by treatment intensity.Based on these results,this study recommends that China focuses more on enhancing clean energy utilization and the effectiveness of treatment processes.展开更多
Micro-nano Earth Observation Satellite(MEOS)constellation has the advantages of low construction cost,short revisit cycle,and high functional density,which is considered a promising solution for serving rapidly growin...Micro-nano Earth Observation Satellite(MEOS)constellation has the advantages of low construction cost,short revisit cycle,and high functional density,which is considered a promising solution for serving rapidly growing observation demands.The observation Scheduling Problem in the MEOS constellation(MEOSSP)is a challenging issue due to the large number of satellites and tasks,as well as complex observation constraints.To address the large-scale and complicated MEOSSP,we develop a Two-Stage Scheduling Algorithm based on the Pointer Network with Attention mechanism(TSSA-PNA).In TSSA-PNA,the MEOS observation scheduling is decomposed into a task allocation stage and a single-MEOS scheduling stage.In the task allocation stage,an adaptive task allocation algorithm with four problem-specific allocation operators is proposed to reallocate the unscheduled tasks to new MEOSs.Regarding the single-MEOS scheduling stage,we design a pointer network based on the encoder-decoder architecture to learn the optimal singleMEOS scheduling solution and introduce the attention mechanism into the encoder to improve the learning efficiency.The Pointer Network with Attention mechanism(PNA)can generate the single-MEOS scheduling solution quickly in an end-to-end manner.These two decomposed stages are performed iteratively to search for the solution with high profit.A greedy local search algorithm is developed to improve the profits further.The performance of the PNA and TSSA-PNA on singleMEOS and multi-MEOS scheduling problems are evaluated in the experiments.The experimental results demonstrate that PNA can obtain the approximate solution for the single-MEOS scheduling problem in a short time.Besides,the TSSA-PNA can achieve higher observation profits than the existing scheduling algorithms within the acceptable computational time for the large-scale MEOS scheduling problem.展开更多
The development of efficient and clean heating technologies is crucial for reducing carbon emissions in regions with severe cold regions.This research designs a novel two-stage phase change heat storage coupled solar-...The development of efficient and clean heating technologies is crucial for reducing carbon emissions in regions with severe cold regions.This research designs a novel two-stage phase change heat storage coupled solar-air source heat pump heating system structure that is specifically designed for such regions.The two-stage heat storage device in this heating system expands the storage temperature range of solar heat.The utilization of the two-stage heat storage device not onlymakes up for the instability of the solar heating system,but can also directlymeet the building heating temperature,and can reduce the influence of low-temperature outdoor environments in severe cold regions on the heating performance of the air source heat pump by using solar energy.Therefore,the two-stage phase change heat storage coupled to the solar energy-air source heat pump heating system effectively improves the utilization rate of solar energy.A numerical model of the system components and their integration was developed using TRNSYS software in this study,and various performance aspects of the system were simulated and analyzed.The simulation results demonstrated that the two-stage heat storage device can effectively store solar energy,enabling its hierarchical utilization.The low-temperature solar energy stored by the two-stage phase change heat storage device enhances the coefficient of performance of the air source heat pump by 11.1%in severe cold conditions.Using the Hooke-Jeeves optimization method,the annual cost and carbon emissions are taken as optimization objectives,with the optimized solar heat supply accounting for 52.5%.This study offers valuable insights into operational strategies and site selection for engineering applications,providing a solid theoretical foundation for the widespread implementation of this system in severe cold regions.展开更多
Integrated-energy systems(IESs)are key to advancing renewable-energy utilization and addressing environmental challenges.Key components of IESs include low-carbon,economic dispatch and demand response,for maximizing r...Integrated-energy systems(IESs)are key to advancing renewable-energy utilization and addressing environmental challenges.Key components of IESs include low-carbon,economic dispatch and demand response,for maximizing renewable-energy consumption and supporting sustainable-energy systems.User participation is central to demand response;however,many users are not inclined to engage actively;therefore,the full potential of demand response remains unrealized.User satisfaction must be prioritized in demand-response assessments.This study proposed a two-stage,capacity-optimization configuration method for user-level energy systems con-sidering thermal inertia and user satisfaction.This method addresses load coordination and complementary issues within the IES and seeks to minimize the annual,total cost for determining equipment capacity configurations while introducing models for system thermal inertia and user satisfaction.Indoor heating is adjusted,for optimizing device output and load profiles,with a focus on typical,daily,economic,and environmental objectives.The studyfindings indicate that the system thermal inertia optimizes energy-system scheduling considering user satisfaction.This optimization mitigates environmental concerns and enhances clean-energy integration.展开更多
BACKGROUND Total knee arthroplasty(TKA)is a widely used treatment for advanced knee osteoarthritis;however,the incidence of failures requiring revision surgery is increasing.Identifying the causes of TKA failure and a...BACKGROUND Total knee arthroplasty(TKA)is a widely used treatment for advanced knee osteoarthritis;however,the incidence of failures requiring revision surgery is increasing.Identifying the causes of TKA failure and assessing the outcomes of revision procedures are essential for improving patient care.We hypothesized that infection and aseptic loosening are the primary causes of TKA failure and that revision TKA(rTKA)significantly enhances functional outcomes.AIM To examine the primary causes of TKA failure and evaluate the functional outcomes following rTKA.METHODS This descriptive study was conducted at the Department of Orthopedic Surgery,Civil Hospital,Bahawalpur,from April to September 2024.A total of 118 patients undergoing rTKA for failed primary TKA were included.Data on demographics,causes of failure,and surgical details were collected.Functional outcomes were evaluated using the Knee Society Score and Visual Analog Scale before and six months after surgery.Statistical analysis was performed using SPSS version 25.0,with statistical significance set at P<0.05.RESULTS The leading causes of TKA failure were infection(45.8%),aseptic loosening(44.1%),and periprosthetic fractures(10.2%).The rTKA significantly improved knee function,with the mean Knee Society Score increasing from 39.43±6.18 to 78.91±6.17(P<0.001).Pain levels decreased substantially,with the mean Visual Analog Scale scores reducing from 7.99±1.37 to 1.42±1.17(P<0.001).No significant differences in outcomes were observed between single-stage and two-stage revision procedures.CONCLUSION Infection and aseptic loosening are the predominant causes of TKA failure.The rTKA effectively enhances knee function and alleviates pain,offering significant benefits to patients.展开更多
As future ship system,hybrid energy ship system has a wide range of application prospects for solving the serious energy crisis.However,current optimization scheduling works lack the consideration of sea conditions an...As future ship system,hybrid energy ship system has a wide range of application prospects for solving the serious energy crisis.However,current optimization scheduling works lack the consideration of sea conditions and navigational circumstances.There-fore,this paper aims at establishing a two-stage optimization framework for hybrid energy ship power system.The proposed framework considers multiple optimizations of route,speed planning,and energy management under the constraints of sea conditions during navigation.First,a complex hybrid ship power model consisting of diesel generation system,propulsion system,energy storage system,photovoltaic power generation system,and electric boiler system is established,where sea state information and ship resistance model are considered.With objective optimization functions of cost and greenhouse gas(GHG)emissions,a two-stage optimization framework consisting of route planning,speed scheduling,and energy management is constructed.Wherein the improved A-star algorithm and grey wolf optimization algorithm are introduced to obtain the optimal solutions for route,speed,and energy optimization scheduling.Finally,simulation cases are employed to verify that the proposed two-stage optimization scheduling model can reduce load energy consumption,operating costs,and carbon emissions by 17.8%,17.39%,and 13.04%,respectively,compared with the non-optimal control group.展开更多
In order to address the synergistic optimization of energy efficiency improvement in the waste incineration power plant(WIPP)and renewable energy accommodation,an electricity-hydrogen-waste multi-energy system integra...In order to address the synergistic optimization of energy efficiency improvement in the waste incineration power plant(WIPP)and renewable energy accommodation,an electricity-hydrogen-waste multi-energy system integrated with phase change material(PCM)thermal storage is proposed.First,a thermal energy management framework is constructed,combining PCM thermal storage with the alkaline electrolyzer(AE)waste heat recovery and the heat pump(HP),while establishing a PCM-driven waste drying system to enhance the efficiency of waste incineration power generation.Next,a flue gas treatment method based on purification-separation-storage coordination is adopted,achieving spatiotemporal decoupling between waste incineration and flue gas treatment.Subsequently,a two-stage optimal dispatching strategy for the multi-energy system is developed:the first stage establishes a dayahead economic dispatch model with the objective of minimizing net system costs,while the second stage introduces model predictive control(MPC)to realize intraday rolling optimization.Finally,The optimal dispatching strategies under different scenarios are obtained using the Gurobi solver,followed by a comparative analysis of the optimized operational outcomes.Simulation results demonstrate that the proposed system optimizes the output and operational states of each unit,simultaneously reducing carbon trading costs while increasing electricity sales revenue.The proposed scheduling strategy demonstrates effective grid peak-shaving functionality,thereby simultaneously improving the system’s economic performance and operational flexibility while providing an innovative technical pathway for municipal solid waste(MSW)resource utilization and low-carbon transformation of energy systems.展开更多
BACKGROUND Leg length discrepancy(LLD)following total hip arthroplasty(THA)is a common complaint,leading to decreased patient satisfaction.However,the effect of LLD before THA on outcomes and complications is not well...BACKGROUND Leg length discrepancy(LLD)following total hip arthroplasty(THA)is a common complaint,leading to decreased patient satisfaction.However,the effect of LLD before THA on outcomes and complications is not well defined.AIM To assess the effect of prior LLD on rates of falls,implant-related complications,stay length,readmissions,and implant survival following THA.METHODS A retrospective review of a nationwide insurance database was conducted from 2010 to 2021.All cases of THA and those with a prior diagnosis of LLD were identified.THA patients with LLD were matched to control patients 1:5 based on demographic and comorbidity profiles.Two-year fall rates and implant complications,lengths of stay,90-day readmissions,and time to revision were compared between cohorts.RESULTS A total of 2038 patients with LLD were matched to 10165 control patients.The LLD group showed significantly greater rates of falls[odds ratio(OR)=1.58;95%confidence interval(95%CI):1.24-2.01],dislocation(OR=2.61;95%CI:2.10-3.24),mechanical loosening(OR=4.58;95%CI:3.28-6.29),and periprosthetic fracture(OR=2.70;95%CI:1.96-3.72)compared to the control group(all P<0.001).Mean length of stay(LOS)was also significantly higher in the LLD group(3.1 days vs 2.8 days,P=0.034).No significant difference in 90-day readmission rates(7.75%vs 7.02%,P=0.244)was observed between the groups(P=0.244).Time to revision was significantly less in the LLD group(225 days vs 544 days,P<0.001).CONCLUSION LLD in patients having THA is related with significantly higher fall risk,rates of implant-related complications,LOS,and quicker time to revision.Identifying patients with LLD before their THA may help in identifying risks,better patient counselling,and more effective preoperative planning.However,the study have important limitations:Its design lacks information on the degree and cause of LLD,the time between diagnosis and surgery,and which leg with the discrepancy underwent the operation.Future well-designed studies should confirm the findings of this study.展开更多
The emission regulations for heavy-duty diesel engines regarding nitrogen oxide(NO_(x))are becoming increasingly stringent,particularly in relation to cold start cycles.While the twostage selective catalytic reduction...The emission regulations for heavy-duty diesel engines regarding nitrogen oxide(NO_(x))are becoming increasingly stringent,particularly in relation to cold start cycles.While the twostage selective catalytic reduction(SCR)has the potential to achieve ultra-low NO_(x) emissions,several challenges remain,including the accurate prediction of ammonia(NH_(3))storage mass and the co-control of the two-stage SCR.The first step in this study involved the establishment of a rapid control prototype platform to facilitate the development and validation of a two-stage SCR control strategy.Secondly,an initial method for predicting the NH_(3) storage based on the mass conservation law was proposed,which was subsequently improved by filling and emptying experiments.The third step involved the development of a two-stage SCR co-control strategy,including obtaining the steady-state NH_(3) storage target value,dynamic correction for NH_(3) storage target value,regulation of NH_(3) storage,and control of the close-coupled SCR urea injector state.Finally,the two-stage SCR urea injection control strategy was certified under the world harmonized transient cycle(WHTC).The results demonstrate that the composite value of engine outlet NO_(x) emissions under cold and hot start WHTC cycles is 13 g/(kW·h).Meanwhile,the composite value of tailpipe NO_(x) emissions under cold and hot start WHTC cycles is 0.065 g/(kW·h),representing only 14%of the EU VI limit value of 0.46 g/(kW·h).Thus,the findings demonstrate that integrating an accurate NH_(3) storage prediction method with the two-stage SCR co-control function is crucial for heavy-duty diesel engines to achieve ultra-low NO_(x) emissions.展开更多
Two racemic pairs of new stilbenoid dimers,(±)-heterosmilaxones A(1)and B(2),with unique 6/6/6and 6/5/7 tricyclic core systems,respectively,were isolated from the rhizomes of Heterosmilax yunnanensis.Their struct...Two racemic pairs of new stilbenoid dimers,(±)-heterosmilaxones A(1)and B(2),with unique 6/6/6and 6/5/7 tricyclic core systems,respectively,were isolated from the rhizomes of Heterosmilax yunnanensis.Their structures were elucidated through comprehensive spectroscopic analyses,quantum chemical calculations and X-ray diffraction crystallography.Compound(+)-1,initially reported as syagrusin A with a 1,4,4a,9a-tetrahydrofluoren-9-one skeleton,is now revised to a new structure characteristic with a benzo bicyclo[3.3.1]nonene scaffold.And compound 2 bears an unprecedented carbon skeleton with four continuous chiral centers in the central benzo bicyclo[4.2.1]nonene motif.Biogenetically,both 1 and2 were proposed to derive from 3,3',4,5,5'-pentahydroxy stilbene and could be generated through key inverse-electron-demand[4+2]and[5+2]cycloadditions,respectively.Interestingly,both(±)-1 and(±)-2 showed significant inhibition againstα-glucosidase.(±)-1 and its pure enantiomers could modulate protein tyrosine phosphatase-1B(PTP1B)enzyme activities and increased glucose consumption in HepG2 cells in a dose-dependent manner.展开更多
文摘BACKGROUND Two-stage revision arthroplasty with an antibiotic-loaded spacer is the treatment of choice in chronically infected total hip arthroplasties.Interval spacers can be functional articulating or prefabricated.Functional results of these spacers have scarcely been reported.AIM To compare retrospectively the patient reported outcome and infection eradication rate after two-stage revision arthroplasty of the hip with the use of a functional articulating or prefabricated spacer.METHODS All patients with two-stage revision of a hip prosthesis at our hospital between 2003 and 2016 were included in this retrospective cohort study.Patients were divided into two groups;patients treated with a functional articulating spacer or with a prefabricated spacer.Patients completed the Hip Osteoarthritis Outcome Score and the EQ-5D-3L(EQ-5D)and the EQ-5D quality of life thermometer(EQVAS)scores.Primary outcomes were patient reported outcome and infection eradication after two-stage revision.The results of both groups were compared to the patient acceptable symptom state for primary arthroplasty of the hip.Secondary outcomes were complications during spacer treatment and at final follow-up.Descriptive statistics,mean and range are used to represent the demographics of the patients.For numerical variables,students’t-tests were used to assess the level of significance for differences between the groups,with 95%confidence intervals;for binary outcome,we used Fisher’s exact test.RESULTS We consecutively treated 55 patients with a prefabricated spacer and 15 patients with a functional articulating spacer of the hip.The infection eradication rates for functional articulating and prefabricated spacers were 93%and 78%,respectively(P>0.05).With respect to the functional outcome,the Hip Osteoarthritis Outcome Score(HOOS)and its subscores(all P<0.01),the EQ-5D(P<0.01)and the EQVAS scores(P<0.05)were all significantly better for patients successfully treated with a functional articulating spacer.More patients in the functional articulating spacer group reached the patient acceptable symptom state for the HOOS pain,HOOS quality of life and EQ-VAS.The number of patients with a spacer dislocation was not significantly different for the functional articulating or prefabricated spacer group(P>0.05).However,the number of dislocations per patient experiencing a dislocation was significantly higher for patients with a prefabricated spacer(P<0.01).CONCLUSION Functional articulating spacers lead to improved patient reported functional outcome and less perioperative complications after two-stage revision arthroplasty of an infected total hip prosthesis,while maintaining a similar infection eradication rate compared to prefabricated spacers.
文摘Periprosthetic joint infection(PJI)following total knee arthroplasty is one of the most catastrophic and costly complications that carries significant patient wellness as well as economic burdens.The road to efficiently diagnosing and treating PJI is challenging,as there is still no gold standard method to reach the diagnosis as early as desired.There are also international controversies with respect to the best approach to manage PJI cases.In this review,we highlight recent advances in managing PJI following knee arthroplasty surgery and discuss in depth the two-stage revision method.
文摘BACKGROUND Periprosthetic joint infection(PJI)is a catastrophic complication that can occur following total knee arthroplasty(TKA).Currently,the treatment for PJI mainly includes the use of antibiotics alone,prosthetic debridement lavage,primary revision,secondary revision,joint fusion,amputation,etc.AIM To explore the clinical effect of two-stage revision surgery for the treatment of PJI after TKA.METHODS The clinical data of 27 patients(3 males and 24 females;age range,47–80 years;mean age,66.7±8.0 years;27 knees)with PJI treated with two-stage revision surgery in our hospital between January 1,2010 and December 31,2020 were analyzed retrospectively.The following outcomes were compared for changes between preoperative and last follow-up results:Erythrocyte sedimentation rate(ESR),C-reactive protein(CRP),visual analogue scale(VAS)scores,Hospital for Special Surgery(HSS)scores,knee range of motion(ROM),and infection cure rates.RESULTS All 27 patients were followed up(range,13–112 mo).The ESR(14.5±6.3 mm/h)and CRP(0.6±0.4 mg/dL)of the patients at the last follow-up were significantly lower than those at admission;the difference was statistically significant(P<0.001).The postoperative VAS score(1.1±0.7),HSS score(82.3±7.1),and knee ROM(108.0°±19.7°)were significantly improved compared with those before the surgery;the difference was statistically significant(P<0.001).Of the 27 patients,26 were cured of the infection,whereas 1 case had an infection recurrence;the infection control rate was 96.3%.CONCLUSION Two-stage revision surgery can effectively relieve pain,control infection,and retain good joint function in the treatment of PJI after TKA.
文摘BACKGROUND Periprosthetic joint infections(PJIs)are frequently caused by coagulase-negative Staphylococci(CoNS),which is known to be a hard-to-treat microorganism.Antibiotic resistance among causative pathogens of PJI is increasing.Two-stage revision is the favoured treatment for chronic CoNS infection of a hip or knee prosthesis.We hypothesised that the infection eradication rate of our treatment protocol for two-stage revision surgery for CoNS PJI of the hip and knee would be comparable to eradication rates described in the literature.AIM To evaluate the infection eradication rate of two-stage revision arthroplasty for PJI caused by CoNS.METHODS All patients treated with two-stage revision of a hip or knee prosthesis were retrospectively included.Patients with CoNS infection were included in the study,including polymicrobial cases.Primary outcome was infection eradication at final follow-up.RESULTS Forty-four patients were included in the study.Twenty-nine patients were treated for PJI of the hip and fifteen for PJI of the knee.At final follow-up after a mean of 37 mo,recurrent or persistent infection was present in eleven patients.CONCLUSION PJI with CoNS can be a difficult to treat infection due to increasing antibiotic resistance.Infection eradication rate of 70%-80%may be achieved.
文摘BACKGROUND Two-stage revision is the most common treatment for chronic periprosthetic joint infection of the hip,involving a resection arthroplasty with or without placement of an antibiotic-loaded spacer,followed by antibiotic therapy before reimplantation.AIM To compare the outcomes and complications of two consecutive treatment protocols for two-stage revision arthroplasty of the infected hip:One using Girdlestone with an antibiotic holiday,the other using custom-made articulating spacers(CUMARS)without an antibiotic holiday.METHODS In this retrospective study,two consecutive cohorts were compared.Group A(2017-2020)underwent two-stage revision with a Girdlestone and an antibiotic holiday before reimplantation,while Group B(2020-2023)received CUMARS whenever possible,and no antibiotic holiday,or a Girdlestone if indicated.The primary outcome was successful infection eradication after one year.Secondary outcomes included surgical duration,length of hospital stay,weight-bearing allowance,discharge destination,and complications.RESULTS A total of 98 patients were included:39 patients in Group A and 59 patients in Group B.Successful infection eradication after one year was achieved in 69%of Group A and 83%of Group B(P=0.164).Patients in Group B were more frequently allowed to bear weight(64%vs 18%,P<0.001),had a shorter in-hospital stay(9 vs 16 days,P<0.001),and were more often discharged home after the first surgery(48%vs 24%,P=0.048).No significant differences were found in(mechanical)complications.CONCLUSION A protocol including CUMARS is a safe and effective treatment,offering faster recovery,shorter length of hospital stay,and enabling more patients to return home during the interval.This reduces strain on patients and the healthcare system,potentially saving costs,without compromising infection control or increasing(mechanical)complications.
文摘A controversial taxon,Hipparion plocodus,is reviewed in the present study.Hi.plocodus has been confirmed to be a valid species with definite diagnostic characteristics,represented by cranial specimens from Baode,Shanxi Province.The phylogenetic analysis performed in the present study,with a new matrix,shows that Hi.plocodus forms a monophyletic group with a European species,Hippotherium malpassii.Actually,no close relationship between so-called Hm.malpassii and the genus Hippotherium has been identified,and the record of stratigraphic range of this genus in late stage of Late Miocene is currently absent.Herein previously Hi.plocodus and Hm.malpassii have both attributed into“Hipparion”before the discovery of better material.Evolutionary stages and correlative absolute age showed that these two species should derive independently from some primitive clade.During the late stage of the Late Miocene,the development of the Asian summer monsoon enhanced the humidity of China,with forest and wood habitats expanding considerably under this setting.As the result,one Eurasian closed-habitat lineage thus extended its range into China,which had become very suited for it,give rise to“Hi.”plocodus.
基金Supported by the National＇Naturai Science Foundation of China （30970638, 21176220 and 31240054）, Zhejiang Provincial Natural Science Foundation （Z13B06008） and the National Basic Research Program of China （2007CB714305）.
文摘Methods to optimize the production of gamma-aminobutyric acid （GABA） by Lactobacillus brevis CGMCC 1306 were investigated. Results indicated that cell growth was maximal at pH 5.0, while pH 4.5 was pref-erable to GABA formation. The optimal temperature for cell growth （35 °C） was lower than that for GABA forma-tion （40 °C）. In a two-stage pH and temperature control fermentation, cultures were maintained at pH 5.0 and 35 °C for 32 h, then adjusted to pH 4.5 and 40 °C, GABA production increased remarkably and reached 474.79 mmol·L-1 at 72 h, while it was 398.63 mmol·L-1 with one stage pH and temperature control process, in which cultivation con-ditions were constantly controlled at pH 5.0 and 35 °C. In order to avoid the inhibition of cell growth at higher L-monosodium glutamate （L-MSG） concentrations, the two-stage control fermentation with substrate feeding strat-egy was applied to GABA production, with 106.87 mmol （20 g） L-MSG supplemented into the shaking-flask at 32 h and 56 h post-inoculation separately. The GABA concentration reached 526.33 mmol·L-1 at 72 h with the fer-mentation volume increased by 38%. These results will provide primary data to realize large-scale production of GABA by L. brevis CGMCC 1306.
基金supported by the National Key R&D Program of China(No.2021YFB3400900)the National Natural Science Foundation of China(Nos.52175373,52205435)+1 种基金Natural Science Foundation of Hunan Province,China(No.2022JJ40621)the Innovation Fund of National Commercial Aircraft Manufacturing Engineering Technology Center,China(No.COMACSFGS-2022-1875)。
文摘A new unified constitutive model was developed to predict the two-stage creep-aging(TSCA)behavior of Al-Zn-Mg-Cu alloys.The particular bimodal precipitation feature was analyzed and modeled by considering the primary micro-variables evolution at different temperatures and their interaction.The dislocation density was incorporated into the model to capture the effect of creep deformation on precipitation.Quantitative transmission electron microscopy and experimental data obtained from a previous study were used to calibrate the model.Subsequently,the developed constitutive model was implemented in the finite element(FE)software ABAQUS via the user subroutines for TSCA process simulation and the springback prediction of an integral panel.A TSCA test was performed.The result shows that the maximum radius deviation between the formed plate and the simulation results is less than 0.4 mm,thus validating the effectiveness of the developed constitutive model and FE model.
基金supported by National Natural Science Foundation of China(Grant No.62266028,62266027,U21B2027,and U24A20334)Major Science and Technology Programs in Yunnan Province(Grant No.202302AD080003,202402AG050007,and 202303AP140008)+1 种基金Yunnan Province Basic Research Program(Grant No.202301AS070047,202301AT070471,and 202401BC070021)Kunming University of Science and Technology's"Double First-rate"construction joint project(Grant No.202201BE070001-021).
文摘Lexical analysis is a fundamental task in natural language processing,which involves several subtasks,such as word segmentation(WS),part-of-speech(POS)tagging,and named entity recognition(NER).Recent works have shown that taking advantage of relatedness between these subtasks can be beneficial.This paper proposes a unified neural framework to address these subtasks simultaneously.Apart from the sequence tagging paradigm,the proposed method tackles the multitask lexical analysis via two-stage sequence span classification.Firstly,the model detects the word and named entity boundaries by multilabel classification over character spans in a sentence.Then,the authors assign POS labels and entity labels for words and named entities by multi-class classification,respectively.Furthermore,a Gated Task Transformation(GTT)is proposed to encourage the model to share valuable features between tasks.The performance of the proposed model was evaluated on Chinese and Thai public datasets,demonstrating state-of-the-art results.
基金Project(52274348)supported by the National Natural Science Foundation of ChinaProject(2022JH1/10400024)supported by the Major Projects for the“Revealed Top”Science and Technology of Liaoning Province,China。
文摘Applying bio-oxidation waste solution(BOS)to chemical-biological two-stage oxidation process can significantly improve the bio-oxidation efficiency of arsenopyrite.This study aims to clarify the enhanced oxidation mechanism of arsenopyrite by evaluating the effects of physical and chemical changes of arsenopyrite in BOS chemical oxidation stage on mineral dissolution kinetics,as well as microbial growth activity and community structure composition in bio-oxidation stage.The results showed that the chemical oxidation contributed to destroying the physical and chemical structure of arsenopyrite surface and reducing the particle size,and led to the formation of nitrogenous substances on mineral surface.These chemical oxidation behaviors effectively promoted Fe^(3+)cycling in the bio-oxidation system and weakened the inhibitory effect of the sulfur film on ionic diffusion,thereby enhancing the dissolution kinetics of the arsenopyrite.Therefore,the bio-oxidation efficiency of arsenopyrite was significantly increased in the two-stage oxidation process.After 18 d,the two-stage oxidation process achieved total extraction rates of(88.8±2.0)%,(86.7±1.3)%,and(74.7±3.0)%for As,Fe,and S elements,respectively.These values represented a significant increase of(50.8±3.4)%,(47.1±2.7)%,and(46.0±0.7)%,respectively,compared to the one-stage bio-oxidation process.
基金the National Natural Science Foundation of China[Grant No.52270183].
文摘Exploring the factors driving the decoupling of China’s sulfur dioxide(SO_(2))emissions from economic growth(DEI)is crucial for achieving sustainable development.By analyzing the decoupling indicators and driving factors at both the generation and treatment stages of SO_(2),more effective targeted mitigation strategies can be developed.We employ the Tapio decoupling model and propose a two-stage method to examine the decoupling issues related to SO_(2).Our findings indicate that:①DEI shows a steady and significant improvement,with SO_(2)emission intensity identified as the primary driver.②for the decoupling of economic growth and SO_(2)generation,energy scale serves as the largest stimulator,while the effect of energy intensity changes from negative to positive,and pollution intensity is first positive and then negative.③For the decoupling of SO_(2)generation and SO_(2)removal,treatment efficiency leads as the largest promoter,followed by treatment intensity.Based on these results,this study recommends that China focuses more on enhancing clean energy utilization and the effectiveness of treatment processes.
基金supported by the National Natural Science Foundation of China(No.62101587)the National Funded Postdoctoral Researcher Program of China(No.GZC20233578)。
文摘Micro-nano Earth Observation Satellite(MEOS)constellation has the advantages of low construction cost,short revisit cycle,and high functional density,which is considered a promising solution for serving rapidly growing observation demands.The observation Scheduling Problem in the MEOS constellation(MEOSSP)is a challenging issue due to the large number of satellites and tasks,as well as complex observation constraints.To address the large-scale and complicated MEOSSP,we develop a Two-Stage Scheduling Algorithm based on the Pointer Network with Attention mechanism(TSSA-PNA).In TSSA-PNA,the MEOS observation scheduling is decomposed into a task allocation stage and a single-MEOS scheduling stage.In the task allocation stage,an adaptive task allocation algorithm with four problem-specific allocation operators is proposed to reallocate the unscheduled tasks to new MEOSs.Regarding the single-MEOS scheduling stage,we design a pointer network based on the encoder-decoder architecture to learn the optimal singleMEOS scheduling solution and introduce the attention mechanism into the encoder to improve the learning efficiency.The Pointer Network with Attention mechanism(PNA)can generate the single-MEOS scheduling solution quickly in an end-to-end manner.These two decomposed stages are performed iteratively to search for the solution with high profit.A greedy local search algorithm is developed to improve the profits further.The performance of the PNA and TSSA-PNA on singleMEOS and multi-MEOS scheduling problems are evaluated in the experiments.The experimental results demonstrate that PNA can obtain the approximate solution for the single-MEOS scheduling problem in a short time.Besides,the TSSA-PNA can achieve higher observation profits than the existing scheduling algorithms within the acceptable computational time for the large-scale MEOS scheduling problem.
基金This work was supported by the project of the Research on Energy Consumption of Office Space in Colleges and Universities under the“Dual Carbon Target”(No.CJ202301006).
文摘The development of efficient and clean heating technologies is crucial for reducing carbon emissions in regions with severe cold regions.This research designs a novel two-stage phase change heat storage coupled solar-air source heat pump heating system structure that is specifically designed for such regions.The two-stage heat storage device in this heating system expands the storage temperature range of solar heat.The utilization of the two-stage heat storage device not onlymakes up for the instability of the solar heating system,but can also directlymeet the building heating temperature,and can reduce the influence of low-temperature outdoor environments in severe cold regions on the heating performance of the air source heat pump by using solar energy.Therefore,the two-stage phase change heat storage coupled to the solar energy-air source heat pump heating system effectively improves the utilization rate of solar energy.A numerical model of the system components and their integration was developed using TRNSYS software in this study,and various performance aspects of the system were simulated and analyzed.The simulation results demonstrated that the two-stage heat storage device can effectively store solar energy,enabling its hierarchical utilization.The low-temperature solar energy stored by the two-stage phase change heat storage device enhances the coefficient of performance of the air source heat pump by 11.1%in severe cold conditions.Using the Hooke-Jeeves optimization method,the annual cost and carbon emissions are taken as optimization objectives,with the optimized solar heat supply accounting for 52.5%.This study offers valuable insights into operational strategies and site selection for engineering applications,providing a solid theoretical foundation for the widespread implementation of this system in severe cold regions.
基金supported by the science and technology foundation of Guizhou province[2022]general 013the science and technology foundation of Guizhou province[2022]general 014+1 种基金the science and technology foundation of Guizhou province GCC[2022]016-1the educational technology foundation of Guizhou province[2022]043.
文摘Integrated-energy systems(IESs)are key to advancing renewable-energy utilization and addressing environmental challenges.Key components of IESs include low-carbon,economic dispatch and demand response,for maximizing renewable-energy consumption and supporting sustainable-energy systems.User participation is central to demand response;however,many users are not inclined to engage actively;therefore,the full potential of demand response remains unrealized.User satisfaction must be prioritized in demand-response assessments.This study proposed a two-stage,capacity-optimization configuration method for user-level energy systems con-sidering thermal inertia and user satisfaction.This method addresses load coordination and complementary issues within the IES and seeks to minimize the annual,total cost for determining equipment capacity configurations while introducing models for system thermal inertia and user satisfaction.Indoor heating is adjusted,for optimizing device output and load profiles,with a focus on typical,daily,economic,and environmental objectives.The studyfindings indicate that the system thermal inertia optimizes energy-system scheduling considering user satisfaction.This optimization mitigates environmental concerns and enhances clean-energy integration.
文摘BACKGROUND Total knee arthroplasty(TKA)is a widely used treatment for advanced knee osteoarthritis;however,the incidence of failures requiring revision surgery is increasing.Identifying the causes of TKA failure and assessing the outcomes of revision procedures are essential for improving patient care.We hypothesized that infection and aseptic loosening are the primary causes of TKA failure and that revision TKA(rTKA)significantly enhances functional outcomes.AIM To examine the primary causes of TKA failure and evaluate the functional outcomes following rTKA.METHODS This descriptive study was conducted at the Department of Orthopedic Surgery,Civil Hospital,Bahawalpur,from April to September 2024.A total of 118 patients undergoing rTKA for failed primary TKA were included.Data on demographics,causes of failure,and surgical details were collected.Functional outcomes were evaluated using the Knee Society Score and Visual Analog Scale before and six months after surgery.Statistical analysis was performed using SPSS version 25.0,with statistical significance set at P<0.05.RESULTS The leading causes of TKA failure were infection(45.8%),aseptic loosening(44.1%),and periprosthetic fractures(10.2%).The rTKA significantly improved knee function,with the mean Knee Society Score increasing from 39.43±6.18 to 78.91±6.17(P<0.001).Pain levels decreased substantially,with the mean Visual Analog Scale scores reducing from 7.99±1.37 to 1.42±1.17(P<0.001).No significant differences in outcomes were observed between single-stage and two-stage revision procedures.CONCLUSION Infection and aseptic loosening are the predominant causes of TKA failure.The rTKA effectively enhances knee function and alleviates pain,offering significant benefits to patients.
基金supported by the National Natural Science Foundation of China under Grant 62473328by the Open Research Fund of Jiangsu Collaborative Innovation Center for Smart Distribution Network,Nanjing Institute of Technology under No.XTCX202203.
文摘As future ship system,hybrid energy ship system has a wide range of application prospects for solving the serious energy crisis.However,current optimization scheduling works lack the consideration of sea conditions and navigational circumstances.There-fore,this paper aims at establishing a two-stage optimization framework for hybrid energy ship power system.The proposed framework considers multiple optimizations of route,speed planning,and energy management under the constraints of sea conditions during navigation.First,a complex hybrid ship power model consisting of diesel generation system,propulsion system,energy storage system,photovoltaic power generation system,and electric boiler system is established,where sea state information and ship resistance model are considered.With objective optimization functions of cost and greenhouse gas(GHG)emissions,a two-stage optimization framework consisting of route planning,speed scheduling,and energy management is constructed.Wherein the improved A-star algorithm and grey wolf optimization algorithm are introduced to obtain the optimal solutions for route,speed,and energy optimization scheduling.Finally,simulation cases are employed to verify that the proposed two-stage optimization scheduling model can reduce load energy consumption,operating costs,and carbon emissions by 17.8%,17.39%,and 13.04%,respectively,compared with the non-optimal control group.
文摘In order to address the synergistic optimization of energy efficiency improvement in the waste incineration power plant(WIPP)and renewable energy accommodation,an electricity-hydrogen-waste multi-energy system integrated with phase change material(PCM)thermal storage is proposed.First,a thermal energy management framework is constructed,combining PCM thermal storage with the alkaline electrolyzer(AE)waste heat recovery and the heat pump(HP),while establishing a PCM-driven waste drying system to enhance the efficiency of waste incineration power generation.Next,a flue gas treatment method based on purification-separation-storage coordination is adopted,achieving spatiotemporal decoupling between waste incineration and flue gas treatment.Subsequently,a two-stage optimal dispatching strategy for the multi-energy system is developed:the first stage establishes a dayahead economic dispatch model with the objective of minimizing net system costs,while the second stage introduces model predictive control(MPC)to realize intraday rolling optimization.Finally,The optimal dispatching strategies under different scenarios are obtained using the Gurobi solver,followed by a comparative analysis of the optimized operational outcomes.Simulation results demonstrate that the proposed system optimizes the output and operational states of each unit,simultaneously reducing carbon trading costs while increasing electricity sales revenue.The proposed scheduling strategy demonstrates effective grid peak-shaving functionality,thereby simultaneously improving the system’s economic performance and operational flexibility while providing an innovative technical pathway for municipal solid waste(MSW)resource utilization and low-carbon transformation of energy systems.
文摘BACKGROUND Leg length discrepancy(LLD)following total hip arthroplasty(THA)is a common complaint,leading to decreased patient satisfaction.However,the effect of LLD before THA on outcomes and complications is not well defined.AIM To assess the effect of prior LLD on rates of falls,implant-related complications,stay length,readmissions,and implant survival following THA.METHODS A retrospective review of a nationwide insurance database was conducted from 2010 to 2021.All cases of THA and those with a prior diagnosis of LLD were identified.THA patients with LLD were matched to control patients 1:5 based on demographic and comorbidity profiles.Two-year fall rates and implant complications,lengths of stay,90-day readmissions,and time to revision were compared between cohorts.RESULTS A total of 2038 patients with LLD were matched to 10165 control patients.The LLD group showed significantly greater rates of falls[odds ratio(OR)=1.58;95%confidence interval(95%CI):1.24-2.01],dislocation(OR=2.61;95%CI:2.10-3.24),mechanical loosening(OR=4.58;95%CI:3.28-6.29),and periprosthetic fracture(OR=2.70;95%CI:1.96-3.72)compared to the control group(all P<0.001).Mean length of stay(LOS)was also significantly higher in the LLD group(3.1 days vs 2.8 days,P=0.034).No significant difference in 90-day readmission rates(7.75%vs 7.02%,P=0.244)was observed between the groups(P=0.244).Time to revision was significantly less in the LLD group(225 days vs 544 days,P<0.001).CONCLUSION LLD in patients having THA is related with significantly higher fall risk,rates of implant-related complications,LOS,and quicker time to revision.Identifying patients with LLD before their THA may help in identifying risks,better patient counselling,and more effective preoperative planning.However,the study have important limitations:Its design lacks information on the degree and cause of LLD,the time between diagnosis and surgery,and which leg with the discrepancy underwent the operation.Future well-designed studies should confirm the findings of this study.
基金supported by the National Natural Science Foundation of China(No.51921004).
文摘The emission regulations for heavy-duty diesel engines regarding nitrogen oxide(NO_(x))are becoming increasingly stringent,particularly in relation to cold start cycles.While the twostage selective catalytic reduction(SCR)has the potential to achieve ultra-low NO_(x) emissions,several challenges remain,including the accurate prediction of ammonia(NH_(3))storage mass and the co-control of the two-stage SCR.The first step in this study involved the establishment of a rapid control prototype platform to facilitate the development and validation of a two-stage SCR control strategy.Secondly,an initial method for predicting the NH_(3) storage based on the mass conservation law was proposed,which was subsequently improved by filling and emptying experiments.The third step involved the development of a two-stage SCR co-control strategy,including obtaining the steady-state NH_(3) storage target value,dynamic correction for NH_(3) storage target value,regulation of NH_(3) storage,and control of the close-coupled SCR urea injector state.Finally,the two-stage SCR urea injection control strategy was certified under the world harmonized transient cycle(WHTC).The results demonstrate that the composite value of engine outlet NO_(x) emissions under cold and hot start WHTC cycles is 13 g/(kW·h).Meanwhile,the composite value of tailpipe NO_(x) emissions under cold and hot start WHTC cycles is 0.065 g/(kW·h),representing only 14%of the EU VI limit value of 0.46 g/(kW·h).Thus,the findings demonstrate that integrating an accurate NH_(3) storage prediction method with the two-stage SCR co-control function is crucial for heavy-duty diesel engines to achieve ultra-low NO_(x) emissions.
基金financially supported by the CAMS Innovation Fund for Medical Sciences(CIFMS,No.2021-I2M-1-028)。
文摘Two racemic pairs of new stilbenoid dimers,(±)-heterosmilaxones A(1)and B(2),with unique 6/6/6and 6/5/7 tricyclic core systems,respectively,were isolated from the rhizomes of Heterosmilax yunnanensis.Their structures were elucidated through comprehensive spectroscopic analyses,quantum chemical calculations and X-ray diffraction crystallography.Compound(+)-1,initially reported as syagrusin A with a 1,4,4a,9a-tetrahydrofluoren-9-one skeleton,is now revised to a new structure characteristic with a benzo bicyclo[3.3.1]nonene scaffold.And compound 2 bears an unprecedented carbon skeleton with four continuous chiral centers in the central benzo bicyclo[4.2.1]nonene motif.Biogenetically,both 1 and2 were proposed to derive from 3,3',4,5,5'-pentahydroxy stilbene and could be generated through key inverse-electron-demand[4+2]and[5+2]cycloadditions,respectively.Interestingly,both(±)-1 and(±)-2 showed significant inhibition againstα-glucosidase.(±)-1 and its pure enantiomers could modulate protein tyrosine phosphatase-1B(PTP1B)enzyme activities and increased glucose consumption in HepG2 cells in a dose-dependent manner.
