BACKGROUND The minimal clinically important difference(MCID)is defined as the smallest meaningful change in a health domain that a patient would identify as important.Thus,an improvement that exceeds the MCID can be u...BACKGROUND The minimal clinically important difference(MCID)is defined as the smallest meaningful change in a health domain that a patient would identify as important.Thus,an improvement that exceeds the MCID can be used to define a successful treatment for the individual patient.AIM To quantify the rate of clinical improvement following anatomical total shoulder arthroplasty for glenohumeral osteoarthritis.METHODS Patients were treated with the Global Unite total shoulder platform arthroplasty between March 2017 and February 2019 at Herlev and Gentofte Hospital,Denmark.The patients were evaluated preoperatively and 3 months,6 months,12 months,and 24 months postoperatively using the Western Ontario Osteoarthritis of the Shoulder index(WOOS),Oxford Shoulder Score(OSS)and Constant-Murley Score(CMS).The rate of clinically relevant improvement was defined as the proportion of patients who had an improvement 24 months postoperatively that exceeded the MCID.Based on previous literature,MCID for WOOS,OSS,and CMS were defined as 12.3,4.3,and 12.8 respectively.RESULTS Forty-nine patients with a Global Unite total shoulder platform arthroplasty were included for the final analysis.Mean age at the time of surgery was 66 years(range 49.0-79.0,SD:8.3)and 65%were women.One patient was revised within the two years follow-up.The mean improvement from the preoperative assessment to the two-year follow-up was 46.1 points[95%confidence interval(95%CI):39.7-53.3,P<0.005]for WOOS,18.2 points(95%CI:15.5-21.0,P<0.005)for OSS and 37.8 points(95%CI:31.5-44.0,P<0.005)for CMS.Two years postoperatively,41 patients(87%)had an improvement in WOOS that exceeded the MCID,45 patients(94%)had an improvement in OSS that exceeded the MCID,and 42 patients(88%)had an improvement in CMS that exceeded the MCID.CONCLUSION Based on three shoulder-specific outcome measures we find that approximately 90%of patients has a clinically relevant improvement.This is a clear message when informing patients about their prognosis.展开更多
The purpose of this research is to evaluate clinical and cost effectiveness of total knee replacement surgery (TKA) for adults hospitalized in the United States between 2010 and 2013. We tried to answer the question t...The purpose of this research is to evaluate clinical and cost effectiveness of total knee replacement surgery (TKA) for adults hospitalized in the United States between 2010 and 2013. We tried to answer the question that whether lower length of stay and higher utilization of post-op facilities would be helpful to control the overall costs. Using the National Hospital Discharge Survey (NHDS) database and cost data from Blue Cross Blue shield, this study seeks to identify which U.S. region renders the highest quality patient care during a three-year span of 2008-2010. Using length of stay and discharge disposition (2010) as input factors, and regional TKA costs (2013) as output factors, Data Envelopment Analysis (DEA), a non-parametric method, illustrated the efficiency ranking of four regions in the US on TKA expenditures. The result shows the West is the most efficient region on controlling the overall cost by shrinking the length of stay and increasing the utilization of short-term/long-term care facilities.展开更多
We consider a replacement policy for a multiple-component cold-standbysystem, and after we analyze this policy, we want to get the mean total cost rate and the preventivepolicy to make it the lowest. In this system, t...We consider a replacement policy for a multiple-component cold-standbysystem, and after we analyze this policy, we want to get the mean total cost rate and the preventivepolicy to make it the lowest. In this system, the failure rate of the component in operation isconstant, and the inspection will control all the processes of the operation. The system isinspected at random points over time to determine whether it is to be replaced. During the process,the replacement decision is based on the number of failed components at the time of inspection.展开更多
The reliability of the product sold under a warranty is usually maintained by the manufacturer during the warranty period. After the expiry of the warranty, however, the consumer confronts a problem about how to maint...The reliability of the product sold under a warranty is usually maintained by the manufacturer during the warranty period. After the expiry of the warranty, however, the consumer confronts a problem about how to maintain the reliability of the product. This paper proposes, from the consumer's perspective, a replacement policy after the extended warranty, under the assumption that the product is sold under the renewable free replacement warranty (RFRW) policy in which the replacement is dependent on the repair-cost threshold. The proposed replacement policy is the replacement after the extended warranty is performed by the consumer based on the repair-cost threshold or preventive replacement (PR) age, which are decision variables. The expected cost rate model is derived from the consumer's perspective. The existence and uniqueness of the optimal solution that minimizes the expected cost rate per unit time are offered. Finally, a numerical example is presented to exemplify the proposed model.展开更多
To solve the problem of residual wind power in offshore wind farms,a hydrogen production system with a reasonable capacity was configured to enhance the local load of wind farms and promote the local consumption of re...To solve the problem of residual wind power in offshore wind farms,a hydrogen production system with a reasonable capacity was configured to enhance the local load of wind farms and promote the local consumption of residual wind power.By studying the mathematical model of wind power output and calculating surplus wind power,as well as considering the hydrogen production/storage characteristics of the electrolyzer and hydrogen storage tank,an innovative capacity optimization allocation model was established.The objective of the model was to achieve the lowest total net present value over the entire life cycle.The model took into account the cost-benefit breakdown of equipment end-of-life cost,replacement cost,residual value gain,wind abandonment penalty,hydrogen transportation,and environmental value.The MATLAB-based platform invoked the CPLEX commercial solver to solve the model.Combined with the analysis of the annual average wind speed data from an offshore wind farm in Guangdong Province,the optimal capacity configuration results and the actual operation of the hydrogen production system were obtained.Under the calculation scenario,this hydrogen production system could consume 3,800 MWh of residual electricity from offshore wind power each year.It could achieve complete consumption of residual electricity from wind power without incurring the penalty cost of wind power.Additionally,it could produce 66,500 kg of green hydrogen from wind power,resulting in hydrogen sales revenue of 3.63 million RMB.It would also reduce pollutant emissions from coal-based hydrogen production by 1.5 tons and realize an environmental value of 4.83 million RMB.The annual net operating income exceeded 6 million RMB and the whole life cycle NPV income exceeded 50 million RMB.These results verified the feasibility and rationality of the established capacity optimization allocation model.The model could help advance power system planning and operation research and assist offshore wind farm operators in improving economic and environmental benefits.展开更多
In the increasingly decentralized energy environment,economical power dispatching from distributed generations(DGs)is crucial to minimizing operating costs,optimizing resource utilization,and guaranteeing a consistent...In the increasingly decentralized energy environment,economical power dispatching from distributed generations(DGs)is crucial to minimizing operating costs,optimizing resource utilization,and guaranteeing a consistent and sustainable supply of electricity.A comprehensive review of optimization techniques for economic power dispatching from distributed generations is imperative to identify the most effective strategies for minimizing operational costs while maintaining grid stability and sustainability.The choice of optimization technique for economic power dispatching from DGs depends on a number of factors,such as the size and complexity of the power system,the availability of computational resources,and the specific requirements of the application.Optimization techniques for economic power dispatching from distributed generations(DGs)can be classified into two main categories:(i)Classical optimization techniques,(ii)Heuristic optimization techniques.In classical optimization techniques,the linear programming(LP)model is one of the most popular optimization methods.Utilizing the LP model,power demand and network constraints are met while minimizing the overall cost of generating electricity from DGs.This approach is efficient in determining the best DGs dispatch and is capable of handling challenging optimization issues in the large-scale system including renewables.The quadratic programming(QP)model,a classical optimization technique,is a further popular optimization method,to consider non-linearity.The QP model can take into account the quadratic cost of energy production,with consideration constraints like network capacity,voltage,and frequency.The metaheuristic optimization techniques are also used for economic power dispatching from DGs,which include genetic algorithms(GA),particle swarm optimization(PSO),and ant colony optimization(ACO).Also,Some researchers are developing hybrid optimization techniques that combine elements of classical and heuristic optimization techniques with the incorporation of droop control,predictive control,and fuzzy-based methods.These methods can deal with large-scale systems with many objectives and non-linear,non-convex optimization issues.The most popular approaches are the LP and QP models,while more difficult problems are handled using metaheuristic optimization techniques.In summary,in order to increase efficiency,reduce costs,and ensure a consistent supply of electricity,optimization techniques are essential tools used in economic power dispatching from DGs.展开更多
The Minimal Invasive Surgery (MIS) technique used for knee arthroplasty implantation implies a less aggressive surgery and reduces the aesthetic impact. Its most notable disadvantage is the poor visualization of bone ...The Minimal Invasive Surgery (MIS) technique used for knee arthroplasty implantation implies a less aggressive surgery and reduces the aesthetic impact. Its most notable disadvantage is the poor visualization of bone structures, which may lead to alterations in the correct placement of the prosthetic components. Navigation-assisted surgery may help avoid such mistakes, and thus navigation coupled with the MIS technique may be an alternative for the future. This is a prospective randomized study of 50 patients who received a total knee arthroplasty. In 25 cases the MIS technique was used, whereas in the other 25 navigation was also employed. Mean age of the patients was 71.63 years, and the mean body mass index was 31.19. Results were assessed based on the definitive radiographic position of the femoral, tibial, and limb axis prosthetic components, as well as according to the Visual Analogue Scale (VAS), the Knee Society Score (KSS), Western Ontarioand McMaster Universities Arthritis Index (WOMAC), Short Form version 12 (SF-12) questionnaires, and the “up-and-go” test. Differences were found between both groups for duration of the procedure (p = 0.0005). No differences were found in the need for analgesics, amount of drained blood, or mean stay time. There were differences regarding the best radiographic position of the tibial component in the navigation group, but not in the final mechanical axis of the limb, even though out-of-range cases were more abundant in the standard-MIS group. At one year after surgery, clinical, functional and quality of life outcomes were similar in both groups. The combined use of surgical navigation and the MIS technique does not yield advantages in terms of limb alignment nor clinical results at one year after surgery.展开更多
Objectives: Hyperglycemia is a well-known marker of poor clinical outcomes in acute myocardial infarction and critical illness;however, its effect in congestive heart failure (CHF) is controversial. We hypothesized th...Objectives: Hyperglycemia is a well-known marker of poor clinical outcomes in acute myocardial infarction and critical illness;however, its effect in congestive heart failure (CHF) is controversial. We hypothesized that persistent hyperglycemia is associated with increased length of stay (LOS) and increased total cost in patients admitted with CHF. Methods: We studied 203 consecutive patients admitted with a primary diagnosis of CHF. Patient characteristics, admission glucose, mean blood glucose (MBG) during the entire hospital stay, length of stay, total cost, and readmission rates were assessed. Persistent hyperglycemia was defined as a MBG level ≥140 mg/dl. Results:Patients with persistent hyperglycemia had longer mean LOS (8.1 vs 5.2 days, p = 0.001) and higher total hospital costs (median $8940 vs $6892, p = 0.01) independent of diabetes status. Similarly, prolonged hospital stay >7 days (38% vs 21%;p = 0.01) and total cost >$10,000/patient (46% vs 29%;p = 0.01) were seen more commonly in patients with poor glucometrics. Neither admission glucose >140 mg/ dL or diabetes status was predictive of total costs or LOS. In multivariate linear regression, only MBG ≥ 140 mg/dl was associated with increased LOS and total cost. Patients with persistent hyperglycemia also had higher 6 months all-cause readmission rates (51% vs 37%;p = 0.03). Conclusion: Persistent hyperglycemia (MBG > 140 mg/dL), but not admission glucose, was associated with increased LOS, total cost and readmission rates independent of diabetes status. Our study emphasizes the need to further examine the role of glycemic control in patients admitted with CHF.展开更多
This paper reaches a recommendation for the 10-year e-bus transition roadmap for New York City. The lifecycle model of emission reduction demonstrates the ecological and financial impacts of a complete transition from...This paper reaches a recommendation for the 10-year e-bus transition roadmap for New York City. The lifecycle model of emission reduction demonstrates the ecological and financial impacts of a complete transition from the current diesel bus fleet to an all-electric bus fleet in New York City by 2033. This study focuses on the NOx pollution, which is the highest among all major cities by Environmental Protection Agency (EPA) and greenhouse gases (GHG) with annual emissions of over five million tons. Our model predicts that switching to an all-electric bus fleet will cut GHG emissions by over 390,000 tons and NOx emissions by over 1300 tons annually, in addition to other pollutants such as VOCs and PM 2.5. yielding an annual economic benefit of over 75.94 million USD. This aligns with the city mayor office’s initiative of achieving total carbon neutrality. We further model an optimized transition roadmap that balances ecological and long-term benefits against the costs of the transition, emphasizing feasibility and alignment with the natural replacement cycle of existing buses, ensuring a steady budgeting pattern to minimize interruptions and resistance. Finally, we advocate for collaboration between government agencies, public transportation authorities, and private sectors, including electric buses and charging facility manufacturers, which is essential for fostering innovation and reducing the costs associated with the transition to e-buses.展开更多
By comparing the related total cost before and after the formation of purchasing consortia, the impetus of formation is analyzed. Moreover, pointed to different transportation and storage policies, the formation impet...By comparing the related total cost before and after the formation of purchasing consortia, the impetus of formation is analyzed. Moreover, pointed to different transportation and storage policies, the formation impetus is studied in detail and some conclusions are arrived at. Finally the research orientation of the formation impetus of purchasing consortia is exploratory presented under more complicated conditions, and purchasing consortia in more cross-zones and multi-segment will occur in China.展开更多
Petroleum products contamination is a world-wide problem that threatens polluting groundwater and surface water systems. However, the problem is not only large-scale in scope when viewed from a case-by-case basis. Man...Petroleum products contamination is a world-wide problem that threatens polluting groundwater and surface water systems. However, the problem is not only large-scale in scope when viewed from a case-by-case basis. Many fueling, construction, agricultural, and industrial activities result in the problem of managing smaller quantities of these soils from an ecological safety perspective. Landfilling has been the disposal method of choice in the US;however, this option is becoming economically prohibitive and it does not really offer a true degradation fate for the pollutants. This study focused on the proving of an innovative biocell design that afforded a high level of petroleum degradation within a simple and cost effective design. Additionally, the design offered a remediation solution for sites not easily accessed. Soil contaminated with both diesel fuel and gasoline collected from a former filling station was used in this on-site remediation case study. Rapid biodegradation of the petroleum products were observed at the initiation of the study with rates leveling off as the study progressed with the final total petroleum hydrocarbon concentration being 10 mg/kg at Day 90. Oxygen uptake rates were monitored and found to nicely track both microbial activity and pollutant removal dynamics. The biocell design met all expectations by being effective, yet simple to build and operate.展开更多
Objective To discuss the postoperative curative effects of two surgical techniques of minimally invasive total hip arthroplasty (THA) using metal-on-metal largediameter and conventional diameter femoral head for the e...Objective To discuss the postoperative curative effects of two surgical techniques of minimally invasive total hip arthroplasty (THA) using metal-on-metal largediameter and conventional diameter femoral head for the elderly patients展开更多
In this paper, we present a novel cloud-based demand side management (DSM) optimization approach for the cost reduction of energy usage in heating, ventilation and air conditioning (HVAC) systems in residential homes ...In this paper, we present a novel cloud-based demand side management (DSM) optimization approach for the cost reduction of energy usage in heating, ventilation and air conditioning (HVAC) systems in residential homes at the district level. The proposed approach achieves optimization through scheduling of HVAC energy usage within permissible bounds set by house users. House smart home energy management (SHEM) devices are connected to the utility/aggregator via a dedicated communication network that is used to enable DSM. Each house SHEM can predict its own HVAC energy usage for the next 24 h using minimalistic deep learning (DL) prediction models. These predictions are communicated to the aggregator, which will then do day ahead optimizations using the proposed game theory (GT) algorithm. The GT model captures the interaction between aggregator and customers and identifies a solution to the GT problem that translates into HVAC energy peak shifting and peak reduction achieved by rescheduling HVAC energy usage. The found solution is communicated by the aggregator to houses SHEM devices in the form of offers via DSM signals. If customers’ SHEM devices accept the offer, then energy cost reduction will be achieved. To validate the proposed algorithm, we conduct extensive simulations with a custom simulation tool based on GridLab-D tool, which is integrated with DL prediction models and optimization libraries. Results show that HVAC energy cost can be reduced by up to 36% while indirectly also reducing the peak-to-average (PAR) and the aggregated net load by up to 9.97%.展开更多
This paper tries to integrate game theory, a very useful tool to resolve conflict phenomena, with optimal capital cost allocation issue in total emission control. First the necessity of allocating optimal capital cos...This paper tries to integrate game theory, a very useful tool to resolve conflict phenomena, with optimal capital cost allocation issue in total emission control. First the necessity of allocating optimal capital costs fairly and reasonably among polluters in total emission control was analyzed. Then the possibility of applying game theory to the issue of the optimal capital cost allocation was expounded. Next the cooperative N person game model of the optimal capital cost allocation and its solution ways including method based on Shapley value, least core method, weak least core methods, proportional least core method, CGA method, MCRS method and so on were delineated. Finally through application of these methods it was concluded that to apply game theory in the optimal capital cost allocation issue is helpful to implement the total emission control planning schemes successfully, to control pollution effectively, and to ensure sustainable development.展开更多
Background:Postoperative care has been evolving since the concept of enhanced recovery after surgery(ERAS)was introduced in China.This study aimed to evaluate the effects of early ambulation within 24h after unilatera...Background:Postoperative care has been evolving since the concept of enhanced recovery after surgery(ERAS)was introduced in China.This study aimed to evaluate the effects of early ambulation within 24h after unilateral total knee arthroplasty(TKA)on postoperative rehabilitation and costs in a Chinese population.Methods:This cohort study of patients with knee osteoarthritis who had undergone TKA at 24 large teaching hospitals between January 2014 and November 2016 involved 2687 patients who began ambulating within 24h(Group A)and 3761 patients who began ambulating later than 24h(Group B).The outcome measurements,such as length of stay(LOS),total hospitalization costs,dynamic pain level,knee flexion range of motion(ROM),results of the 12-Item Short Form Survey(SF-12),incidence of thromboembolic events and other complications,were recorded and compared.Results:The early ambulation group(Group A)had a shorter LOS and lower hospitalization costs and pain levels than the late ambulation group(Group B).There was a favorable effect in enhancing ROM for patients in Group A compared with patients in Group B.In Group A,patients had significantly higher postoperative SF-12 scores than those in Group B.The incidence of deep venous thrombosis(DVT)and pulmonary infection was significantly lower in Group A than in Group B.The incidence of pulmonary embolism(PE)and other complications did not differ between the two groups.Conclusions:Early ambulation within 24h after TKA was associated with reduced LOS,improved knee function,lower hospitalization costs and lower incidence of DVT and pulmonary infection in the Chinese population.展开更多
Bone cement has the capacity to release antibiotic molecules if any antibiotic is included in it, and these elution properties are improved as cement porosity is increased. In vitro studies have shown high local antib...Bone cement has the capacity to release antibiotic molecules if any antibiotic is included in it, and these elution properties are improved as cement porosity is increased. In vitro studies have shown high local antibiotic concentration for many hours or few days after its use. Antibiotic loaded bone cement(ALBC) is helpful when treating an infection in total knee arthroplasty(TKA) revision surgery. The purpose of this paper was to review the evidence for the routine use of ALBC in TKA in the literature, its pros and cons. Many authors have recommended the use of ALBC also in primary TKA for infection prophylaxis, but the evidence based on data from National Registries, randomized clinical trials and meta-analysis suggest a protective effect of ALBC against infection when used in hips, but not(or only mild) in knees. A possible explanation to this finding is that the duration and quantity of locally elevated antibiotic levels after surgery are smaller in TKA, due to the smaller amount of cement used for fixation in TKA-only a layer in the bone surface. There are some concerns about the routine use of ALBC in primary TKA as prophylaxis against infection: Firstly, there is a risk of hypersensivity or toxicity even when the chance is highly improbable. Secondly, there is a reduction in the mechanical properties of the cement, but this can be probably neglected if the antibiotic is used in low doses, not more than 1 g per 40 g cement package. Another significant concern is the increased economic cost, which could be overlooked if there were enough savings in treating fewer prosthetic infections. Finally, there is also a risk of selection of antibiotic-resistant strains of bacteria and this could be the main concern. If used, the choice of the antibiotic mixed in ALBC should consider microbiological aspects(broad antimicrobial spectrum and low rate of resistant bacteria), physical and chemical aspects(thermal stability, high water solubility), pharmacological characteristics(low risk to allergic reactions or toxicity) and economic aspects(not too expensive). The most commonly used antibiotics in ALBC are gentamicin, tobramycin and vancomycin. In conclusion, there is a paucity of randomized clinical trials in the use of ALBC in primary TKAs and the actual evidence of the effect of ALBC in reducing the risk of infection is insufficient. This, in addition to concerns about patient safety, risks of increase in the antibiotic resistance of microorganisms and the increase in costs in the procedure, lead us to recommend a cautious use of ALBC, perhaps only in high-risk patients(immunocompromised, morbidly obese, diabetic and patients with previous history of fracture or infection around the knee) unless the benefits of ALBC use were fully proven. Meanwhile, the rigorous use of peri-operative prophylactic systemic antibiotics and adoption of efficient antiseptic procedures and improved surgical techniques must be considered the gold standard in infection prevention in TKA surgery.展开更多
This article presents a distributed periodic eventtriggered(PET)optimal control scheme to achieve generation cost minimization and average bus voltage regulation in DC microgrids.In order to accommodate the generation...This article presents a distributed periodic eventtriggered(PET)optimal control scheme to achieve generation cost minimization and average bus voltage regulation in DC microgrids.In order to accommodate the generation constraints of the distributed generators(DGs),a virtual incremental cost is firstly designed,based on which an optimality condition is derived to facilitate the control design.To meet the discrete-time(DT)nature of modern control systems,the optimal controller is directly developed in the DT domain.Afterward,to reduce the communication requirement among the controllers,a distributed event-triggered mechanism is introduced for the DT optimal controller.The event-triggered condition is detected periodically and therefore naturally avoids the Zeno phenomenon.The closed-loop system stability is proved by the Lyapunov synthesis for switched systems.The generation cost minimization and average bus voltage regulation are obtained at the equilibrium point.Finally,switch-level microgrid simulations validate the performance of the proposed optimal controller.展开更多
The fuzzy sets theory is introduced into the fatigue reliability analysis. The concepts of maximizing set and minimizing set are developed to decide the ordering value of each fuzzy number, and these values can be use...The fuzzy sets theory is introduced into the fatigue reliability analysis. The concepts of maximizing set and minimizing set are developed to decide the ordering value of each fuzzy number, and these values can be used to determine the order of the fuzzy numbers. On the basis of the works mentioned above, the membership function defining the fuzzy safety event can be calculated, and then the fuzzy reliability in the case of stress and fuzzy fatigue strength is deduced. An example is given to illustrate the method.展开更多
Decreasing petroleum reserves and growing alternative fuels requirements have promoted the study of biodiesel production. In this work, two thermally coupled reactive distillation designs for biodiesel production were...Decreasing petroleum reserves and growing alternative fuels requirements have promoted the study of biodiesel production. In this work, two thermally coupled reactive distillation designs for biodiesel production were investigated, and the sensitivity analysis was conducted to obtain the appropriate design values. The thermodynamic analysis and economics evaluation were performed to estimate the superiority of the thermally coupled designs over the base case. The proposed biodiesel production processes were simulated using the simulator Aspen Plus, and calculation results show that the exergy loss and economic cost in the two thermally coupled designs can be greatly reduced. It is found that the thermally coupled side-stripper reactive distillation design provides more economic benefits than the side-rectifier one. The dynamic performance of the thermally coupled side-stripper design was investigated and the results showed that the proposed control structure could effectively handle large feed disturbances.展开更多
Over the last decade,with the acceptance of the need for improvements in the outcome of patients affected with rectal cancer,there has been a significant increase in the literature regarding treatment options availabl...Over the last decade,with the acceptance of the need for improvements in the outcome of patients affected with rectal cancer,there has been a significant increase in the literature regarding treatment options available to patients affected by this disease.That treatment related decisions should be made at a high volume multidisciplinary tumor board,after pre-operative rectal magnetic resonance imaging and the importance of total mesorectal excision(TME)are accepted standard of care.More controversial is the emerging role for watchful waiting rather than radical surgery in complete pathologic responders,which may be appropriate in 20%of patients.Patients with early T1 rectal cancers and favorable pathologic features can be cured with local excision only,with transanal minimal invasive surgery(TAMIS)because of its versatility and almost universal availability of the necessary equipment and skillset in the average laparoscopic surgeon,emerging as the leading option.Recent trials have raised concerns about the oncologic outcomes of the standard"top-down"TME hence transanal TME(Ta TME"bottom-up")approach has gained popularity as an alternative.The challenges are many,with a dearth of evidence of the oncologic superiority in the long-term for any given option.However,this review highlights recent advances in the role of chemoradiation only for complete pathologic responders,TAMIS for highly selected early rectal cancer patients and Ta TME as options to improve cure rates whilst maintaining quality of life in these patients,while we await the results of further definitive trials being currently conducted.展开更多
文摘BACKGROUND The minimal clinically important difference(MCID)is defined as the smallest meaningful change in a health domain that a patient would identify as important.Thus,an improvement that exceeds the MCID can be used to define a successful treatment for the individual patient.AIM To quantify the rate of clinical improvement following anatomical total shoulder arthroplasty for glenohumeral osteoarthritis.METHODS Patients were treated with the Global Unite total shoulder platform arthroplasty between March 2017 and February 2019 at Herlev and Gentofte Hospital,Denmark.The patients were evaluated preoperatively and 3 months,6 months,12 months,and 24 months postoperatively using the Western Ontario Osteoarthritis of the Shoulder index(WOOS),Oxford Shoulder Score(OSS)and Constant-Murley Score(CMS).The rate of clinically relevant improvement was defined as the proportion of patients who had an improvement 24 months postoperatively that exceeded the MCID.Based on previous literature,MCID for WOOS,OSS,and CMS were defined as 12.3,4.3,and 12.8 respectively.RESULTS Forty-nine patients with a Global Unite total shoulder platform arthroplasty were included for the final analysis.Mean age at the time of surgery was 66 years(range 49.0-79.0,SD:8.3)and 65%were women.One patient was revised within the two years follow-up.The mean improvement from the preoperative assessment to the two-year follow-up was 46.1 points[95%confidence interval(95%CI):39.7-53.3,P<0.005]for WOOS,18.2 points(95%CI:15.5-21.0,P<0.005)for OSS and 37.8 points(95%CI:31.5-44.0,P<0.005)for CMS.Two years postoperatively,41 patients(87%)had an improvement in WOOS that exceeded the MCID,45 patients(94%)had an improvement in OSS that exceeded the MCID,and 42 patients(88%)had an improvement in CMS that exceeded the MCID.CONCLUSION Based on three shoulder-specific outcome measures we find that approximately 90%of patients has a clinically relevant improvement.This is a clear message when informing patients about their prognosis.
文摘The purpose of this research is to evaluate clinical and cost effectiveness of total knee replacement surgery (TKA) for adults hospitalized in the United States between 2010 and 2013. We tried to answer the question that whether lower length of stay and higher utilization of post-op facilities would be helpful to control the overall costs. Using the National Hospital Discharge Survey (NHDS) database and cost data from Blue Cross Blue shield, this study seeks to identify which U.S. region renders the highest quality patient care during a three-year span of 2008-2010. Using length of stay and discharge disposition (2010) as input factors, and regional TKA costs (2013) as output factors, Data Envelopment Analysis (DEA), a non-parametric method, illustrated the efficiency ranking of four regions in the US on TKA expenditures. The result shows the West is the most efficient region on controlling the overall cost by shrinking the length of stay and increasing the utilization of short-term/long-term care facilities.
文摘We consider a replacement policy for a multiple-component cold-standbysystem, and after we analyze this policy, we want to get the mean total cost rate and the preventivepolicy to make it the lowest. In this system, the failure rate of the component in operation isconstant, and the inspection will control all the processes of the operation. The system isinspected at random points over time to determine whether it is to be replaced. During the process,the replacement decision is based on the number of failed components at the time of inspection.
基金supported by the National Natural Science Foundation of China(7147114771631001)+1 种基金the Basic Research Project of Natural Science in Shaanxi Province(2015JQ7273)the 111 Project(B13044)
文摘The reliability of the product sold under a warranty is usually maintained by the manufacturer during the warranty period. After the expiry of the warranty, however, the consumer confronts a problem about how to maintain the reliability of the product. This paper proposes, from the consumer's perspective, a replacement policy after the extended warranty, under the assumption that the product is sold under the renewable free replacement warranty (RFRW) policy in which the replacement is dependent on the repair-cost threshold. The proposed replacement policy is the replacement after the extended warranty is performed by the consumer based on the repair-cost threshold or preventive replacement (PR) age, which are decision variables. The expected cost rate model is derived from the consumer's perspective. The existence and uniqueness of the optimal solution that minimizes the expected cost rate per unit time are offered. Finally, a numerical example is presented to exemplify the proposed model.
基金supported by Manage Innovation Project of China Southern Power Grid Co.,Ltd.(No.GZHKJXM20210232).
文摘To solve the problem of residual wind power in offshore wind farms,a hydrogen production system with a reasonable capacity was configured to enhance the local load of wind farms and promote the local consumption of residual wind power.By studying the mathematical model of wind power output and calculating surplus wind power,as well as considering the hydrogen production/storage characteristics of the electrolyzer and hydrogen storage tank,an innovative capacity optimization allocation model was established.The objective of the model was to achieve the lowest total net present value over the entire life cycle.The model took into account the cost-benefit breakdown of equipment end-of-life cost,replacement cost,residual value gain,wind abandonment penalty,hydrogen transportation,and environmental value.The MATLAB-based platform invoked the CPLEX commercial solver to solve the model.Combined with the analysis of the annual average wind speed data from an offshore wind farm in Guangdong Province,the optimal capacity configuration results and the actual operation of the hydrogen production system were obtained.Under the calculation scenario,this hydrogen production system could consume 3,800 MWh of residual electricity from offshore wind power each year.It could achieve complete consumption of residual electricity from wind power without incurring the penalty cost of wind power.Additionally,it could produce 66,500 kg of green hydrogen from wind power,resulting in hydrogen sales revenue of 3.63 million RMB.It would also reduce pollutant emissions from coal-based hydrogen production by 1.5 tons and realize an environmental value of 4.83 million RMB.The annual net operating income exceeded 6 million RMB and the whole life cycle NPV income exceeded 50 million RMB.These results verified the feasibility and rationality of the established capacity optimization allocation model.The model could help advance power system planning and operation research and assist offshore wind farm operators in improving economic and environmental benefits.
文摘In the increasingly decentralized energy environment,economical power dispatching from distributed generations(DGs)is crucial to minimizing operating costs,optimizing resource utilization,and guaranteeing a consistent and sustainable supply of electricity.A comprehensive review of optimization techniques for economic power dispatching from distributed generations is imperative to identify the most effective strategies for minimizing operational costs while maintaining grid stability and sustainability.The choice of optimization technique for economic power dispatching from DGs depends on a number of factors,such as the size and complexity of the power system,the availability of computational resources,and the specific requirements of the application.Optimization techniques for economic power dispatching from distributed generations(DGs)can be classified into two main categories:(i)Classical optimization techniques,(ii)Heuristic optimization techniques.In classical optimization techniques,the linear programming(LP)model is one of the most popular optimization methods.Utilizing the LP model,power demand and network constraints are met while minimizing the overall cost of generating electricity from DGs.This approach is efficient in determining the best DGs dispatch and is capable of handling challenging optimization issues in the large-scale system including renewables.The quadratic programming(QP)model,a classical optimization technique,is a further popular optimization method,to consider non-linearity.The QP model can take into account the quadratic cost of energy production,with consideration constraints like network capacity,voltage,and frequency.The metaheuristic optimization techniques are also used for economic power dispatching from DGs,which include genetic algorithms(GA),particle swarm optimization(PSO),and ant colony optimization(ACO).Also,Some researchers are developing hybrid optimization techniques that combine elements of classical and heuristic optimization techniques with the incorporation of droop control,predictive control,and fuzzy-based methods.These methods can deal with large-scale systems with many objectives and non-linear,non-convex optimization issues.The most popular approaches are the LP and QP models,while more difficult problems are handled using metaheuristic optimization techniques.In summary,in order to increase efficiency,reduce costs,and ensure a consistent supply of electricity,optimization techniques are essential tools used in economic power dispatching from DGs.
文摘The Minimal Invasive Surgery (MIS) technique used for knee arthroplasty implantation implies a less aggressive surgery and reduces the aesthetic impact. Its most notable disadvantage is the poor visualization of bone structures, which may lead to alterations in the correct placement of the prosthetic components. Navigation-assisted surgery may help avoid such mistakes, and thus navigation coupled with the MIS technique may be an alternative for the future. This is a prospective randomized study of 50 patients who received a total knee arthroplasty. In 25 cases the MIS technique was used, whereas in the other 25 navigation was also employed. Mean age of the patients was 71.63 years, and the mean body mass index was 31.19. Results were assessed based on the definitive radiographic position of the femoral, tibial, and limb axis prosthetic components, as well as according to the Visual Analogue Scale (VAS), the Knee Society Score (KSS), Western Ontarioand McMaster Universities Arthritis Index (WOMAC), Short Form version 12 (SF-12) questionnaires, and the “up-and-go” test. Differences were found between both groups for duration of the procedure (p = 0.0005). No differences were found in the need for analgesics, amount of drained blood, or mean stay time. There were differences regarding the best radiographic position of the tibial component in the navigation group, but not in the final mechanical axis of the limb, even though out-of-range cases were more abundant in the standard-MIS group. At one year after surgery, clinical, functional and quality of life outcomes were similar in both groups. The combined use of surgical navigation and the MIS technique does not yield advantages in terms of limb alignment nor clinical results at one year after surgery.
文摘Objectives: Hyperglycemia is a well-known marker of poor clinical outcomes in acute myocardial infarction and critical illness;however, its effect in congestive heart failure (CHF) is controversial. We hypothesized that persistent hyperglycemia is associated with increased length of stay (LOS) and increased total cost in patients admitted with CHF. Methods: We studied 203 consecutive patients admitted with a primary diagnosis of CHF. Patient characteristics, admission glucose, mean blood glucose (MBG) during the entire hospital stay, length of stay, total cost, and readmission rates were assessed. Persistent hyperglycemia was defined as a MBG level ≥140 mg/dl. Results:Patients with persistent hyperglycemia had longer mean LOS (8.1 vs 5.2 days, p = 0.001) and higher total hospital costs (median $8940 vs $6892, p = 0.01) independent of diabetes status. Similarly, prolonged hospital stay >7 days (38% vs 21%;p = 0.01) and total cost >$10,000/patient (46% vs 29%;p = 0.01) were seen more commonly in patients with poor glucometrics. Neither admission glucose >140 mg/ dL or diabetes status was predictive of total costs or LOS. In multivariate linear regression, only MBG ≥ 140 mg/dl was associated with increased LOS and total cost. Patients with persistent hyperglycemia also had higher 6 months all-cause readmission rates (51% vs 37%;p = 0.03). Conclusion: Persistent hyperglycemia (MBG > 140 mg/dL), but not admission glucose, was associated with increased LOS, total cost and readmission rates independent of diabetes status. Our study emphasizes the need to further examine the role of glycemic control in patients admitted with CHF.
文摘This paper reaches a recommendation for the 10-year e-bus transition roadmap for New York City. The lifecycle model of emission reduction demonstrates the ecological and financial impacts of a complete transition from the current diesel bus fleet to an all-electric bus fleet in New York City by 2033. This study focuses on the NOx pollution, which is the highest among all major cities by Environmental Protection Agency (EPA) and greenhouse gases (GHG) with annual emissions of over five million tons. Our model predicts that switching to an all-electric bus fleet will cut GHG emissions by over 390,000 tons and NOx emissions by over 1300 tons annually, in addition to other pollutants such as VOCs and PM 2.5. yielding an annual economic benefit of over 75.94 million USD. This aligns with the city mayor office’s initiative of achieving total carbon neutrality. We further model an optimized transition roadmap that balances ecological and long-term benefits against the costs of the transition, emphasizing feasibility and alignment with the natural replacement cycle of existing buses, ensuring a steady budgeting pattern to minimize interruptions and resistance. Finally, we advocate for collaboration between government agencies, public transportation authorities, and private sectors, including electric buses and charging facility manufacturers, which is essential for fostering innovation and reducing the costs associated with the transition to e-buses.
文摘By comparing the related total cost before and after the formation of purchasing consortia, the impetus of formation is analyzed. Moreover, pointed to different transportation and storage policies, the formation impetus is studied in detail and some conclusions are arrived at. Finally the research orientation of the formation impetus of purchasing consortia is exploratory presented under more complicated conditions, and purchasing consortia in more cross-zones and multi-segment will occur in China.
文摘Petroleum products contamination is a world-wide problem that threatens polluting groundwater and surface water systems. However, the problem is not only large-scale in scope when viewed from a case-by-case basis. Many fueling, construction, agricultural, and industrial activities result in the problem of managing smaller quantities of these soils from an ecological safety perspective. Landfilling has been the disposal method of choice in the US;however, this option is becoming economically prohibitive and it does not really offer a true degradation fate for the pollutants. This study focused on the proving of an innovative biocell design that afforded a high level of petroleum degradation within a simple and cost effective design. Additionally, the design offered a remediation solution for sites not easily accessed. Soil contaminated with both diesel fuel and gasoline collected from a former filling station was used in this on-site remediation case study. Rapid biodegradation of the petroleum products were observed at the initiation of the study with rates leveling off as the study progressed with the final total petroleum hydrocarbon concentration being 10 mg/kg at Day 90. Oxygen uptake rates were monitored and found to nicely track both microbial activity and pollutant removal dynamics. The biocell design met all expectations by being effective, yet simple to build and operate.
文摘Objective To discuss the postoperative curative effects of two surgical techniques of minimally invasive total hip arthroplasty (THA) using metal-on-metal largediameter and conventional diameter femoral head for the elderly patients
基金supported by the National Science Foundation(NSF)grant ECCF 1936494.
文摘In this paper, we present a novel cloud-based demand side management (DSM) optimization approach for the cost reduction of energy usage in heating, ventilation and air conditioning (HVAC) systems in residential homes at the district level. The proposed approach achieves optimization through scheduling of HVAC energy usage within permissible bounds set by house users. House smart home energy management (SHEM) devices are connected to the utility/aggregator via a dedicated communication network that is used to enable DSM. Each house SHEM can predict its own HVAC energy usage for the next 24 h using minimalistic deep learning (DL) prediction models. These predictions are communicated to the aggregator, which will then do day ahead optimizations using the proposed game theory (GT) algorithm. The GT model captures the interaction between aggregator and customers and identifies a solution to the GT problem that translates into HVAC energy peak shifting and peak reduction achieved by rescheduling HVAC energy usage. The found solution is communicated by the aggregator to houses SHEM devices in the form of offers via DSM signals. If customers’ SHEM devices accept the offer, then energy cost reduction will be achieved. To validate the proposed algorithm, we conduct extensive simulations with a custom simulation tool based on GridLab-D tool, which is integrated with DL prediction models and optimization libraries. Results show that HVAC energy cost can be reduced by up to 36% while indirectly also reducing the peak-to-average (PAR) and the aggregated net load by up to 9.97%.
文摘This paper tries to integrate game theory, a very useful tool to resolve conflict phenomena, with optimal capital cost allocation issue in total emission control. First the necessity of allocating optimal capital costs fairly and reasonably among polluters in total emission control was analyzed. Then the possibility of applying game theory to the issue of the optimal capital cost allocation was expounded. Next the cooperative N person game model of the optimal capital cost allocation and its solution ways including method based on Shapley value, least core method, weak least core methods, proportional least core method, CGA method, MCRS method and so on were delineated. Finally through application of these methods it was concluded that to apply game theory in the optimal capital cost allocation issue is helpful to implement the total emission control planning schemes successfully, to control pollution effectively, and to ensure sustainable development.
基金the National Health and Family Planning Commission of the People’s Republic of China(CN)program(201302007).
文摘Background:Postoperative care has been evolving since the concept of enhanced recovery after surgery(ERAS)was introduced in China.This study aimed to evaluate the effects of early ambulation within 24h after unilateral total knee arthroplasty(TKA)on postoperative rehabilitation and costs in a Chinese population.Methods:This cohort study of patients with knee osteoarthritis who had undergone TKA at 24 large teaching hospitals between January 2014 and November 2016 involved 2687 patients who began ambulating within 24h(Group A)and 3761 patients who began ambulating later than 24h(Group B).The outcome measurements,such as length of stay(LOS),total hospitalization costs,dynamic pain level,knee flexion range of motion(ROM),results of the 12-Item Short Form Survey(SF-12),incidence of thromboembolic events and other complications,were recorded and compared.Results:The early ambulation group(Group A)had a shorter LOS and lower hospitalization costs and pain levels than the late ambulation group(Group B).There was a favorable effect in enhancing ROM for patients in Group A compared with patients in Group B.In Group A,patients had significantly higher postoperative SF-12 scores than those in Group B.The incidence of deep venous thrombosis(DVT)and pulmonary infection was significantly lower in Group A than in Group B.The incidence of pulmonary embolism(PE)and other complications did not differ between the two groups.Conclusions:Early ambulation within 24h after TKA was associated with reduced LOS,improved knee function,lower hospitalization costs and lower incidence of DVT and pulmonary infection in the Chinese population.
文摘Bone cement has the capacity to release antibiotic molecules if any antibiotic is included in it, and these elution properties are improved as cement porosity is increased. In vitro studies have shown high local antibiotic concentration for many hours or few days after its use. Antibiotic loaded bone cement(ALBC) is helpful when treating an infection in total knee arthroplasty(TKA) revision surgery. The purpose of this paper was to review the evidence for the routine use of ALBC in TKA in the literature, its pros and cons. Many authors have recommended the use of ALBC also in primary TKA for infection prophylaxis, but the evidence based on data from National Registries, randomized clinical trials and meta-analysis suggest a protective effect of ALBC against infection when used in hips, but not(or only mild) in knees. A possible explanation to this finding is that the duration and quantity of locally elevated antibiotic levels after surgery are smaller in TKA, due to the smaller amount of cement used for fixation in TKA-only a layer in the bone surface. There are some concerns about the routine use of ALBC in primary TKA as prophylaxis against infection: Firstly, there is a risk of hypersensivity or toxicity even when the chance is highly improbable. Secondly, there is a reduction in the mechanical properties of the cement, but this can be probably neglected if the antibiotic is used in low doses, not more than 1 g per 40 g cement package. Another significant concern is the increased economic cost, which could be overlooked if there were enough savings in treating fewer prosthetic infections. Finally, there is also a risk of selection of antibiotic-resistant strains of bacteria and this could be the main concern. If used, the choice of the antibiotic mixed in ALBC should consider microbiological aspects(broad antimicrobial spectrum and low rate of resistant bacteria), physical and chemical aspects(thermal stability, high water solubility), pharmacological characteristics(low risk to allergic reactions or toxicity) and economic aspects(not too expensive). The most commonly used antibiotics in ALBC are gentamicin, tobramycin and vancomycin. In conclusion, there is a paucity of randomized clinical trials in the use of ALBC in primary TKAs and the actual evidence of the effect of ALBC in reducing the risk of infection is insufficient. This, in addition to concerns about patient safety, risks of increase in the antibiotic resistance of microorganisms and the increase in costs in the procedure, lead us to recommend a cautious use of ALBC, perhaps only in high-risk patients(immunocompromised, morbidly obese, diabetic and patients with previous history of fracture or infection around the knee) unless the benefits of ALBC use were fully proven. Meanwhile, the rigorous use of peri-operative prophylactic systemic antibiotics and adoption of efficient antiseptic procedures and improved surgical techniques must be considered the gold standard in infection prevention in TKA surgery.
基金supported by the U.S.Office of Naval Research(N00014-21-1-2175)。
文摘This article presents a distributed periodic eventtriggered(PET)optimal control scheme to achieve generation cost minimization and average bus voltage regulation in DC microgrids.In order to accommodate the generation constraints of the distributed generators(DGs),a virtual incremental cost is firstly designed,based on which an optimality condition is derived to facilitate the control design.To meet the discrete-time(DT)nature of modern control systems,the optimal controller is directly developed in the DT domain.Afterward,to reduce the communication requirement among the controllers,a distributed event-triggered mechanism is introduced for the DT optimal controller.The event-triggered condition is detected periodically and therefore naturally avoids the Zeno phenomenon.The closed-loop system stability is proved by the Lyapunov synthesis for switched systems.The generation cost minimization and average bus voltage regulation are obtained at the equilibrium point.Finally,switch-level microgrid simulations validate the performance of the proposed optimal controller.
基金This project is supported by National Naied Science Foundation of China(59475043). Manuscript received on July 8,1999 revised m
文摘The fuzzy sets theory is introduced into the fatigue reliability analysis. The concepts of maximizing set and minimizing set are developed to decide the ordering value of each fuzzy number, and these values can be used to determine the order of the fuzzy numbers. On the basis of the works mentioned above, the membership function defining the fuzzy safety event can be calculated, and then the fuzzy reliability in the case of stress and fuzzy fatigue strength is deduced. An example is given to illustrate the method.
基金Financial supports of the National Natural Science Foundation of China(Grant:21276279 and Grant:21476261)the Fundamental Research Funds for the Central Universities(No.14CX05030ANo.15CX06042A)
文摘Decreasing petroleum reserves and growing alternative fuels requirements have promoted the study of biodiesel production. In this work, two thermally coupled reactive distillation designs for biodiesel production were investigated, and the sensitivity analysis was conducted to obtain the appropriate design values. The thermodynamic analysis and economics evaluation were performed to estimate the superiority of the thermally coupled designs over the base case. The proposed biodiesel production processes were simulated using the simulator Aspen Plus, and calculation results show that the exergy loss and economic cost in the two thermally coupled designs can be greatly reduced. It is found that the thermally coupled side-stripper reactive distillation design provides more economic benefits than the side-rectifier one. The dynamic performance of the thermally coupled side-stripper design was investigated and the results showed that the proposed control structure could effectively handle large feed disturbances.
文摘Over the last decade,with the acceptance of the need for improvements in the outcome of patients affected with rectal cancer,there has been a significant increase in the literature regarding treatment options available to patients affected by this disease.That treatment related decisions should be made at a high volume multidisciplinary tumor board,after pre-operative rectal magnetic resonance imaging and the importance of total mesorectal excision(TME)are accepted standard of care.More controversial is the emerging role for watchful waiting rather than radical surgery in complete pathologic responders,which may be appropriate in 20%of patients.Patients with early T1 rectal cancers and favorable pathologic features can be cured with local excision only,with transanal minimal invasive surgery(TAMIS)because of its versatility and almost universal availability of the necessary equipment and skillset in the average laparoscopic surgeon,emerging as the leading option.Recent trials have raised concerns about the oncologic outcomes of the standard"top-down"TME hence transanal TME(Ta TME"bottom-up")approach has gained popularity as an alternative.The challenges are many,with a dearth of evidence of the oncologic superiority in the long-term for any given option.However,this review highlights recent advances in the role of chemoradiation only for complete pathologic responders,TAMIS for highly selected early rectal cancer patients and Ta TME as options to improve cure rates whilst maintaining quality of life in these patients,while we await the results of further definitive trials being currently conducted.