The knowledge representation mode and inference control strategy were analyzed according to the specialties of air-conditioning cooling/heating sources selection. The constructing idea and working procedure for knowle...The knowledge representation mode and inference control strategy were analyzed according to the specialties of air-conditioning cooling/heating sources selection. The constructing idea and working procedure for knowledge base and inference engine were proposed while the realization technique of the C language was discussed. An intelligent decision support system (IDSS) model based on such knowledge representation and inference mechanism was developed by domain engineers. The model was verified to have a small kernel and powerful capability in list processing and data driving, which was successfully used in the design of a cooling/heating sources system for a large-sized office building.展开更多
A water loop variable refrigerant flow(WLVRF)air-conditioning system is designed to be applied in large-scale buildings in northern China.The system is energy saving and it is an integrated system consisting of a va...A water loop variable refrigerant flow(WLVRF)air-conditioning system is designed to be applied in large-scale buildings in northern China.The system is energy saving and it is an integrated system consisting of a variable refrigerant flow(VRF)air-conditioning unit,a water loop and an air source heat pump.The water loop transports energy among different regions in the buildings instead of refrigerant pipes,decreasing the scale of the VRF air-conditioning unit and improving the performance.Previous models for refrigerants and building loads are cited in this investigation.Mathematical models of major equipment and other elements of the system are established using the lumped parameter method based on the DATAFIT software and the MATLAB software.The performance of the WLVRF system is simulated.The initial investments and the running costs are calculated based on the results of market research.Finally,a contrast is carried out between the WLVRF system and the traditional VRF system.The results show that the WLVRF system has a better working condition and lower running costs than the traditional VRF system.展开更多
Evaluation of the quality of small-bowel cleansing is required to assess the reliability of findings in capsule endoscopy(CE). Moreover, consensus regarding the need of intestinal preparation for CE remains to be achi...Evaluation of the quality of small-bowel cleansing is required to assess the reliability of findings in capsule endoscopy(CE). Moreover, consensus regarding the need of intestinal preparation for CE remains to be achieved. The presence of multiple grading scales for smallbowel preparation in CE, which are time-consuming and complicated, adds difficulty to the comparison of different small-bowel cleansing regimens and their application in clinical practice. Nowadays, a validated scale universally accepted for grading small-bowel cleansing is lacking. In fact, there are numerous grading systems with very different technical characteristics, namely, the parameters and the portion of the CE video that are analyzed, the objectivity of the analysis, the lesser or greater dependency on the operator, and the validation of the score. The authors performed a review which aims to systematize and summarize currently available smallbowel grading scales in CE.展开更多
AIM:To suggest a new cleansing score system for small bowel preparation and to evaluate its clinical efficacy.METHODS:Twenty capsule endoscopy cases were reviewed and small bowel preparation was assessed with the new ...AIM:To suggest a new cleansing score system for small bowel preparation and to evaluate its clinical efficacy.METHODS:Twenty capsule endoscopy cases were reviewed and small bowel preparation was assessed with the new scoring system.For the assessment,two visual parameters were used:proportion of visualized mucosa and degree of obscuration.Representative frames from small bowel images were serially selected and scored at 5-min intervals.Intraclass correlation coefficient(ICC)was obtained to assess the reliability of the new scoring system.For efficacy evaluation and validation,scores of our new scoring system were compared with another previously reported cleansing grading system.RESULTS:Concordance with the previous system,inter-observer agreement,and intra-patient agreement were excellent with ICC values of 0.82,0.80,and 0.76,respectively.The intra-observer agreements at four-week intervals were also excellent.The cutoff value of adequate image quality was found to be 2.25.CONCLUSION:Our new scoring system is simple,efficient,and can be considered to be applicable in clinical practice and research.展开更多
The incidence of colorectal cancer(CRC)is characterized by rapid declines in the wake of widespread screening.Colonoscopy is the gold standard for CRC screening,but its accuracy is related to high quality of bowel pre...The incidence of colorectal cancer(CRC)is characterized by rapid declines in the wake of widespread screening.Colonoscopy is the gold standard for CRC screening,but its accuracy is related to high quality of bowel preparation(BP).In this review,we aimed to summarized the current strategy to increase bowel cleansing before colonoscopy.Newly bowel cleansing agents were developed with the same efficacy of previous agent but requiring less amount of liquid to improve patients’acceptability.The role of the diet before colonoscopy was also changed,as well the contribution of educational intervention and the use of adjunctive drugs to improve patients’tolerance and/or quality of BP.The review also described BP in special situations,as lower gastrointestinal bleeding,elderly people,patients with chronic kidney disease,patients with inflammatory bowel disease,patients with congestive heart failure,inpatient,patient with previous bowel resection,pregnant/lactating patients.The review underlined the quality of BP should be described using a validate scale in colonoscopy report and it explored the available scales.Finally,the review explored the possible contribution of bowel cleansing in post-colonoscopy syndrome that can be related by a transient alteration of gut microbiota.Moreover,the study underlined several points needed to further investigations.展开更多
BACKGROUND No consensus has been reached in patients suspected of having inadequate bowel preparation regarding optimal salvage methods, which negatively affects the efficacy and quality of colonoscopy. The most ideal...BACKGROUND No consensus has been reached in patients suspected of having inadequate bowel preparation regarding optimal salvage methods, which negatively affects the efficacy and quality of colonoscopy. The most ideal and reasonable rescue option involves early suspicion and identification of patients with inadequate preparation before sedation, additional oral ingestion of a suitable preparation formulation, and same-day colonoscopy.AIM To compare 0.5-L and 1-L polyethylene glycol containing ascorbic acid(PEG +Asc) as additional bowel cleansing methods after a 2-L split-dose PEG + Asc regimen in patients with expected inadequate bowel preparation before colonoscopy.METHODS Individuals with expected inadequate bowel preparation based on last stool form, such as turbid liquid, particulate liquid, or liquid with small amounts of feces, were randomized to either a 0.5-L PEG + Asc group or a 1-L PEG + Asc group. The primary endpoint was bowel preparation as assessed using the Aronchick bowel preparation scale(ABPS) and Boston bowel preparation scale(BBPS) scores. The secondary endpoints were cecal intubation time, withdrawal time, polyp detection rate(PDR), adenoma detection rate(ADR), individual compliance with additional PEG + Asc, and patient satisfaction.RESULTS Initially, 98 patients were included, but 8 were later excluded due to withdrawal of consent to participate in the study. Adequate bowel preparation(as assessed by ABPS) was observed in 80.9%(38/47) of subjects in the 0.5-L group and in88.4%(38/43) of subjects in the 1-L group(P = 0.617). Mean total BBPS was 6.7 points in the 0.5-L group and 7.0 points in the 1-L group(P = 0.458). ADRs and PDRs were similar in the two groups, and cecal intubation and withdrawal times were not significantly different. However, mean patient satisfaction score was significantly higher in the 0.5-L group(P = 0.041).CONCLUSION The bowel cleaning efficacy of additional 0.5-L PEG + Asc was not inferior to that of 1-L PEG + Asc. Additional 0.5-L PEG + Asc is worthwhile when inadequate bowel preparation is expected before colonoscopy.展开更多
This paper presented an entropy evaluation method for the influences of condense heat recovery system on the environment.Aiming at the damage of the condense heat to the environment,an entropy of resource loss and an ...This paper presented an entropy evaluation method for the influences of condense heat recovery system on the environment.Aiming at the damage of the condense heat to the environment,an entropy of resource loss and an emission entropy from the condense heat recovery system in the air conditioning refrigerating machine were introduced.For the evaluation of the entropies,we developed a new algorithm for the parameter identification,called the composite influence coefficient,based on the Least Squares Support Vector Machine method.By simulation,the numerical experiments shows that the Least Squares Support Vector Machine method is one of the powerful methods for the parameter identification to compute the damage entropy of the condense heat,with the largest training error being-0.025(the relative error being-3.56%),and the biggest test error being 0.015(the relative error being 2.5%).展开更多
To explore the relationship between summer office set air-conditioning temperature and energy consumption related to air conditioning use to provide human thermal comfort,a comparison experiment was conducted in three...To explore the relationship between summer office set air-conditioning temperature and energy consumption related to air conditioning use to provide human thermal comfort,a comparison experiment was conducted in three similar offices at temperatures of 24,26 and 28 ℃ respectively. A thermal comfort questionnaire survey was conducted. It is demonstrated that air-conditioner energy consumption at the set temperature of 28 ℃ is 113% and 271% lower than at 26 ℃ and 24 ℃,respectively. A linear relationship exists between air-conditioner energy consumption and the indoor and outdoor temperature difference. When comfortably dressed,over 80% of research participants accept the set temperature of 28 ℃. The regression analysis leads to a neutral temperature of 26.2 ℃ and an acceptable temperature of 28.2 ℃ for over 80% of the research participants subjects,indicating that the current 26 ℃ set temperature for offices in summer,required by Chinese General Office of the State Council,can be increased to 28 ℃. Moreover,analysis of predicted mean vote(PMV) index shows that a set temperature of 27 ℃,not 26 ℃,is sufficiently comfortable for office staff wearing long-sleeve shirts,long pants and leather shoes.展开更多
Variable-air-volume (VAV) air-conditioning system is a multi-variable system and has multi coupling control loops. While all of the control loops are working together, they interfere and influence each other. A multiv...Variable-air-volume (VAV) air-conditioning system is a multi-variable system and has multi coupling control loops. While all of the control loops are working together, they interfere and influence each other. A multivariable decoupling PID controller is designed for VAV air-conditioning system. Diagonal matrix decoupling method is employed to eliminate the coupling between the loop of supply air temperature and that of thermal-space air temperature. The PID controller parameters are optimized by means of an improved genetic algorithm in floating point representations to obtain better performance. The population in the improved genetic algorithm mutates before crossover, which is helpful for the convergence. Additionally the micro mutation algorithm is proposed and applied to improve the convergence during the later evolution. To search the best parameters, the optimized parameters ranges should be amplified 10 times the initial ideal parameters. The simulation and experiment results show that the decoupling control system is effective and feasible. The method can overcome the strong coupling feature of the system and has shorter governing time and less over-shoot than non-optimization PID control.展开更多
BACKGROUND Four-liter polyethylene glycol(PEG)solutions are effective for bowel cleansing,but their large volume might hinder patient compliance.Due to the unique features of Asians,4 L PEG might be a suboptimal bowel...BACKGROUND Four-liter polyethylene glycol(PEG)solutions are effective for bowel cleansing,but their large volume might hinder patient compliance.Due to the unique features of Asians,4 L PEG might be a suboptimal bowel preparation in predominantly ethnically Asian countries.In view of this,a balance should be achieved between the volume and effectiveness.The ideal bowel cleansing regimen for a colonoscopy has yet to be determined in a Chinese population.AIM To compare the cleansing efficacy of 3 L PEG plus simethicone with 4 L PEG.METHODS A total of 291 patients were randomly allocated to two groups:Group 1(n=145)received 4 L split-dose PEG(4-P);group 2(n=146)received 3 L split-dose PEG plus simethicone(3-PS).Bowel-cleansing efficacy was evaluated by endoscopists using the Boston bowel preparation scale(BBPS)and the bubbles score.RESULTS Although there were no significant differences in the total BBPS score or the adequate rate of bowel preparation between the two groups,the BBPS score of the right-side colon was significantly higher in the 3-SP group(2.37±0.54 vs 2.21±0.78;P=0.04).Moreover,the use of simethicone significantly reduced bubbles in all colon segments(P<0.001).The mean withdrawal time was significantly shorter in the 3-PS group(8.8±3.4 vs 9.6±2.3;P=0.02).Furthermore,significantly more proximal adenomas were detected in the 3-PS group(53.6%vs 45.7%;P=0.03).In addition,the proportions of patients with nausea and bloating were significantly lower in the 3-SP group(P<0.01 for both).More patients in the 3-PS group expressed willingness to repeat the bowel preparation(87.7%vs 76.6%,P=0.01).CONCLUSION Three-liter PEG shows satisfactory bowel cleansing despite the decrease in dosage,and addition of simethicone with better bubble elimination and enhanced patient acceptance offers excellent potential impact on the detection of proximal adenomas in Chinese patients.展开更多
As the rapid development of aviation industry and newly emerging crowd-sourcing projects such as Flightradar24 and FlightAware,large amount of air traffic data,particularly four-dimension(4D)trajectory data,have becom...As the rapid development of aviation industry and newly emerging crowd-sourcing projects such as Flightradar24 and FlightAware,large amount of air traffic data,particularly four-dimension(4D)trajectory data,have become available for the public.In order to guarantee the accuracy and reliability of results,data cleansing is the first step in analyzing 4D trajectory data,including error identification and mitigation.Data cleansing techniques for the 4D trajectory data are investigated.Back propagation(BP)neural network algorithm is applied to repair errors.Newton interpolation method is used to obtain even-spaced trajectory samples over a uniform distribution of each flight’s 4D trajectory data.Furthermore,a new method is proposed to compress data while maintaining the intrinsic characteristics of the trajectories.Density-based spatial clustering of applications with noise(DBSCAN)is applied to identify remaining outliers of sample points.Experiments are performed on a data set of one-day 4D trajectory data over Europe.The results show that the proposed method can achieve more efficient and effective results than the existing approaches.The work contributes to the first step of data preprocessing and lays foundation for further downstream 4D trajectory analysis.展开更多
Surfactant, an abbreviation for the surface-active agent, is utilized in almost every industry. It brings two immiscible phases such as oil and water into one single homogeneous phase, leading to various industrial ap...Surfactant, an abbreviation for the surface-active agent, is utilized in almost every industry. It brings two immiscible phases such as oil and water into one single homogeneous phase, leading to various industrial applications such as food, painting, coating, drug delivery as well as cosmetics. The use of surfactants in skin cleansing is very common to keep skin healthy. Their function herein is to lower the interfacial tension at the dirt/water and skin/water interfaces, thereby detaching dirt, extra sebum or oils from the skin surface. But this application could bring side effects attributed to the penetration of surfactants into the skin, including skin proteins denaturation, stratum corneum lipids removal or even lipids organization disruption in the stratum corneum. This review summarizes modern mild skin cleansing technologies, which address the side effects brought by the surfactants.展开更多
Two building factors-a longer thermal lag of more than one hour for building envelops and a lag of indoor radiation to convert into cooling load-have impact on the instantaneous heat input and instantaneous cooling lo...Two building factors-a longer thermal lag of more than one hour for building envelops and a lag of indoor radiation to convert into cooling load-have impact on the instantaneous heat input and instantaneous cooling load.So the two factors should be taken into account when selecting the weather parameters for air-conditioning system design.This paper developed a new statistic method for the rational selection of coincident solar irradiance,dry-bulb and wet-bulb temperatures.The method was applied to historic weather records of 25 years in Hong Kong to generate coincident design weather data.And the results show that traditional design solar irradiance,dry-bulb and wet-bulb temperatures may be significantly overestimated in many conditions,and the design weather data for the three different constructions is not kept constant.展开更多
BACKGROUND Research data from patient reports indicate that the least bearable part of colonoscopy is the administration of laxatives for bowel preparation.AIM To observe the intestinal cleansing efficacy and safety o...BACKGROUND Research data from patient reports indicate that the least bearable part of colonoscopy is the administration of laxatives for bowel preparation.AIM To observe the intestinal cleansing efficacy and safety of sodium picosulfate/magnesium citrate and to discuss the patients’experiences due to the procedure.METHODS Subjects hospitalized in the International Medical Center Ward of Peking University International Hospital,Beijing,China,from April 29 to October 29,2020,for whom the colonoscopy was planned,were enrolled.Bowel preparation was performed using sodium picosulfate/magnesium citrate.The effect of bowel cleansing was evaluated according to the Ottawa Bowel Preparation Scale,defecation conditions and adverse reactions were recorded,and the comfort level and subjective satisfaction concerning medication were evaluated by the visual analogue scale/score(VAS).RESULTS The bowel preparation procedure was planned for all patients enrolled,which included 42 males and 22 females.The results showed an average liquid rehydration volume of 3000 mL,an average onset of action for the first dose at 89.04 min,an average number of bowel movements of 4.3 following the first dose,an average onset of action for the second dose at 38.90 min and an average number of bowel movements of 5.0 after the second dose.The total average Ottawa Bowel Preparation Scale score was 3.6,with 93.55%of bowel preparations in the“qualified”and 67.74%in the“excellent”grade.The average VAS score of effect on sleep was 0,and the average VAS score of perianal pain was also 0.The average VAS score for ease of taking and taste perception of the bowel cleanser was 10.Side effects included mild to moderate nausea(15.63%),mild vomiting(4.69%),mild to moderate abdominal pain(7.81%),mild to moderate abdominal distension(20.31%),mild palpitation(7.81%)and mild dizziness(4.69%).CONCLUSION Sodium picosulfate/magnesium citrate is effective and safe for bowel preparation before colonoscopy with high subjective patient acceptance,thus improving overall patient compliance.展开更多
The aim of this research was to study and design a solid desiccant dehumidification system suitable for tropical climate to reduce the latent load of air-conditioning system and improve the thermal comfort. Different ...The aim of this research was to study and design a solid desiccant dehumidification system suitable for tropical climate to reduce the latent load of air-conditioning system and improve the thermal comfort. Different dehumidifiers such as desiccant column and desiccant wheel were investigated. The ANSYS and TRASYS software were used to predict the results of dehumidifiers and the desiccant cooling systems, respectively. The desiccant bed contained approximately 15 kg of silica-gel, with 3 mm average diameter. Results indicated that the pressure drop and the adsorption rate of desiccant column are usually higher than those of the desiccant wheel. The feasible and practical adsorption rate of desiccant wheel was 0.102 kgw/h at air flow rate 1.0 kg/min, regenerated air temperature of 55?C and at a wheel speed of 2.5 rpm. The humidity ratio of conditioning space and cooling load of split-type air conditioner was decreased to 0.002 kgw/kgda (14%) and 0.71 kWth (19.26%), respectively. Consequently, the thermal comfort was improved from 0.5 PMV (10.12% PPD) to 0.3 PMV (7.04% PPD).展开更多
An energy-saving control strategy based on predictive control for central air-conditioning systems is proposed in this paper. The cold load model is developed to describe the dynamic characteristics of temperature con...An energy-saving control strategy based on predictive control for central air-conditioning systems is proposed in this paper. The cold load model is developed to describe the dynamic characteristics of temperature control systems, and then parameters in the cold load model and in the central air-conditioning system model are estimated. Generalized predictive control (GPC) is used to establish an optimization model to minimize the consumption of energy and the control error of temperature. The simulated annealing (SA) algorithm, combined with quadratic programming, is adopted to solve the optimal problem. Contrasted with the simulation of traditional PID control, the results prove the effectiveness of this proposed strategy.展开更多
As the conceptual design of air-conditioning is done using the theory of Quality Function Deployment (QFD),cus- tomer requirements should be understood and the product competitive power be analyzed as exactly as possi...As the conceptual design of air-conditioning is done using the theory of Quality Function Deployment (QFD),cus- tomer requirements should be understood and the product competitive power be analyzed as exactly as possible for new product de- signing.Lots of information in the process of this research is fuzzy and uncertain,but traditional QFD can not deal with it well. Fuzzy theory can solve the problem.So a fuzzy model for analyzing product competitive power is formulated in this paper to im- prove traditional QFD,after that it is applied to analyze air-conditioning competitive power.When air-conditioning competitive power is analyzed using this model,firstly the importance weight of the customer requirements o fair-conditioning is determined us- ing the Analytic Hierarchy Process (AHP) weighting process,then air-conditloning competitive power is evaluated using fuzzy comprehensive evaluation.It is proved that the model is feasible and has good applicability.展开更多
Colonoscopy is a crucial diagnostic instrument for colorectal cancer screening and an adequate bowel preparation is definitely decisive for the success of the procedure. Especially in elderly patients, bowel cleansing...Colonoscopy is a crucial diagnostic instrument for colorectal cancer screening and an adequate bowel preparation is definitely decisive for the success of the procedure. Especially in elderly patients, bowel cleansing is considered a big issue, because it is often poorly tolerated for many reasons(like inability to swallow large volume of liquids or unlikable taste); this can cause a suboptimal preparation that may lead to miss a neoplastic lesion. There is relatively little data about how to improve preparation tolerability. The purpose of our pilot study was to analyze the effect of prucalopride(Resolor~?), a highly selective serotonin 5HT4 receptor agonist used for chronic constipation for its ability to stimulate gastrointestinal peristalsis, undertaken the day before colonoscopy, followed by half volume of polyethylene glycol solution. We found that this can be a good and safe method to achieve an adequate and better-tolerated colon cleansing.展开更多
An explosion-proof dual throttling air-conditioning system was put forward to solve the heat dissipation and internal dewing problems of explosion-proof frequency converter in the underground coal mine. This study inv...An explosion-proof dual throttling air-conditioning system was put forward to solve the heat dissipation and internal dewing problems of explosion-proof frequency converter in the underground coal mine. This study investigated the feasibility and benefits of explosion-proof dual throttling cooling and dehumidification air-conditioning system applied to the explosion-proof frequency converter. The physical model of dual throttling air-conditioning system was established and its performance parameter was described by mathematical method. The design calculation of the system has also been done. The experimental result showed that the system reached the steady state at the refrigeration mode after running 45 min, and the maximum internal temperature of the flame-proof cavity was 31.0 ℃. The system reached the steady state at the dehumidification mode after running 37 min. The maximum internal relative humidity and temperature of the flame-proof cavity were 33.4% and 36.3 ℃, respectively. Therefore, the proposed system had excellent ability of heat dissipation and avoided internal dewing. Compared with water cooling system, it was more energy-saving and economical. The airflow field of dual throttling air-conditioning system was also studied by CFD simulation. It was found that the result of CFD numerical simulation was highly consistent with the experimental data.展开更多
The artificial intelligence is applied to the simulation of the automotive air-conditioning system ( AACS )According to the system's characteristics a model of AACS, based on neural network, is developed. Differen...The artificial intelligence is applied to the simulation of the automotive air-conditioning system ( AACS )According to the system's characteristics a model of AACS, based on neural network, is developed. Different control methods of AACS are discussed through simulation based on this model. The result shows that the neural- fuzzy control is the best one compared with the on-off control and conventional fuzzy control method.It can make the compartment's temperature descend rapidly to the designed temperature and the fluctuation is small.展开更多
文摘The knowledge representation mode and inference control strategy were analyzed according to the specialties of air-conditioning cooling/heating sources selection. The constructing idea and working procedure for knowledge base and inference engine were proposed while the realization technique of the C language was discussed. An intelligent decision support system (IDSS) model based on such knowledge representation and inference mechanism was developed by domain engineers. The model was verified to have a small kernel and powerful capability in list processing and data driving, which was successfully used in the design of a cooling/heating sources system for a large-sized office building.
文摘A water loop variable refrigerant flow(WLVRF)air-conditioning system is designed to be applied in large-scale buildings in northern China.The system is energy saving and it is an integrated system consisting of a variable refrigerant flow(VRF)air-conditioning unit,a water loop and an air source heat pump.The water loop transports energy among different regions in the buildings instead of refrigerant pipes,decreasing the scale of the VRF air-conditioning unit and improving the performance.Previous models for refrigerants and building loads are cited in this investigation.Mathematical models of major equipment and other elements of the system are established using the lumped parameter method based on the DATAFIT software and the MATLAB software.The performance of the WLVRF system is simulated.The initial investments and the running costs are calculated based on the results of market research.Finally,a contrast is carried out between the WLVRF system and the traditional VRF system.The results show that the WLVRF system has a better working condition and lower running costs than the traditional VRF system.
文摘Evaluation of the quality of small-bowel cleansing is required to assess the reliability of findings in capsule endoscopy(CE). Moreover, consensus regarding the need of intestinal preparation for CE remains to be achieved. The presence of multiple grading scales for smallbowel preparation in CE, which are time-consuming and complicated, adds difficulty to the comparison of different small-bowel cleansing regimens and their application in clinical practice. Nowadays, a validated scale universally accepted for grading small-bowel cleansing is lacking. In fact, there are numerous grading systems with very different technical characteristics, namely, the parameters and the portion of the CE video that are analyzed, the objectivity of the analysis, the lesser or greater dependency on the operator, and the validation of the score. The authors performed a review which aims to systematize and summarize currently available smallbowel grading scales in CE.
文摘AIM:To suggest a new cleansing score system for small bowel preparation and to evaluate its clinical efficacy.METHODS:Twenty capsule endoscopy cases were reviewed and small bowel preparation was assessed with the new scoring system.For the assessment,two visual parameters were used:proportion of visualized mucosa and degree of obscuration.Representative frames from small bowel images were serially selected and scored at 5-min intervals.Intraclass correlation coefficient(ICC)was obtained to assess the reliability of the new scoring system.For efficacy evaluation and validation,scores of our new scoring system were compared with another previously reported cleansing grading system.RESULTS:Concordance with the previous system,inter-observer agreement,and intra-patient agreement were excellent with ICC values of 0.82,0.80,and 0.76,respectively.The intra-observer agreements at four-week intervals were also excellent.The cutoff value of adequate image quality was found to be 2.25.CONCLUSION:Our new scoring system is simple,efficient,and can be considered to be applicable in clinical practice and research.
文摘The incidence of colorectal cancer(CRC)is characterized by rapid declines in the wake of widespread screening.Colonoscopy is the gold standard for CRC screening,but its accuracy is related to high quality of bowel preparation(BP).In this review,we aimed to summarized the current strategy to increase bowel cleansing before colonoscopy.Newly bowel cleansing agents were developed with the same efficacy of previous agent but requiring less amount of liquid to improve patients’acceptability.The role of the diet before colonoscopy was also changed,as well the contribution of educational intervention and the use of adjunctive drugs to improve patients’tolerance and/or quality of BP.The review also described BP in special situations,as lower gastrointestinal bleeding,elderly people,patients with chronic kidney disease,patients with inflammatory bowel disease,patients with congestive heart failure,inpatient,patient with previous bowel resection,pregnant/lactating patients.The review underlined the quality of BP should be described using a validate scale in colonoscopy report and it explored the available scales.Finally,the review explored the possible contribution of bowel cleansing in post-colonoscopy syndrome that can be related by a transient alteration of gut microbiota.Moreover,the study underlined several points needed to further investigations.
文摘BACKGROUND No consensus has been reached in patients suspected of having inadequate bowel preparation regarding optimal salvage methods, which negatively affects the efficacy and quality of colonoscopy. The most ideal and reasonable rescue option involves early suspicion and identification of patients with inadequate preparation before sedation, additional oral ingestion of a suitable preparation formulation, and same-day colonoscopy.AIM To compare 0.5-L and 1-L polyethylene glycol containing ascorbic acid(PEG +Asc) as additional bowel cleansing methods after a 2-L split-dose PEG + Asc regimen in patients with expected inadequate bowel preparation before colonoscopy.METHODS Individuals with expected inadequate bowel preparation based on last stool form, such as turbid liquid, particulate liquid, or liquid with small amounts of feces, were randomized to either a 0.5-L PEG + Asc group or a 1-L PEG + Asc group. The primary endpoint was bowel preparation as assessed using the Aronchick bowel preparation scale(ABPS) and Boston bowel preparation scale(BBPS) scores. The secondary endpoints were cecal intubation time, withdrawal time, polyp detection rate(PDR), adenoma detection rate(ADR), individual compliance with additional PEG + Asc, and patient satisfaction.RESULTS Initially, 98 patients were included, but 8 were later excluded due to withdrawal of consent to participate in the study. Adequate bowel preparation(as assessed by ABPS) was observed in 80.9%(38/47) of subjects in the 0.5-L group and in88.4%(38/43) of subjects in the 1-L group(P = 0.617). Mean total BBPS was 6.7 points in the 0.5-L group and 7.0 points in the 1-L group(P = 0.458). ADRs and PDRs were similar in the two groups, and cecal intubation and withdrawal times were not significantly different. However, mean patient satisfaction score was significantly higher in the 0.5-L group(P = 0.041).CONCLUSION The bowel cleaning efficacy of additional 0.5-L PEG + Asc was not inferior to that of 1-L PEG + Asc. Additional 0.5-L PEG + Asc is worthwhile when inadequate bowel preparation is expected before colonoscopy.
基金Supported by Program of Science and Technology of Hunan Province(2007FJ2006)Project the Program of Science and Tech-nology of Hunan Province(2007TP4030)Hunan Provincial Natural Science Foundation of China(08JJ3093)
文摘This paper presented an entropy evaluation method for the influences of condense heat recovery system on the environment.Aiming at the damage of the condense heat to the environment,an entropy of resource loss and an emission entropy from the condense heat recovery system in the air conditioning refrigerating machine were introduced.For the evaluation of the entropies,we developed a new algorithm for the parameter identification,called the composite influence coefficient,based on the Least Squares Support Vector Machine method.By simulation,the numerical experiments shows that the Least Squares Support Vector Machine method is one of the powerful methods for the parameter identification to compute the damage entropy of the condense heat,with the largest training error being-0.025(the relative error being-3.56%),and the biggest test error being 0.015(the relative error being 2.5%).
基金Project(50838009) supported by the National Natural Science Foundation of ChinaProjects(2006BAJ02A09,2006BAJ02A13-4) supported by the National Key Technologies R & D Program of China
文摘To explore the relationship between summer office set air-conditioning temperature and energy consumption related to air conditioning use to provide human thermal comfort,a comparison experiment was conducted in three similar offices at temperatures of 24,26 and 28 ℃ respectively. A thermal comfort questionnaire survey was conducted. It is demonstrated that air-conditioner energy consumption at the set temperature of 28 ℃ is 113% and 271% lower than at 26 ℃ and 24 ℃,respectively. A linear relationship exists between air-conditioner energy consumption and the indoor and outdoor temperature difference. When comfortably dressed,over 80% of research participants accept the set temperature of 28 ℃. The regression analysis leads to a neutral temperature of 26.2 ℃ and an acceptable temperature of 28.2 ℃ for over 80% of the research participants subjects,indicating that the current 26 ℃ set temperature for offices in summer,required by Chinese General Office of the State Council,can be increased to 28 ℃. Moreover,analysis of predicted mean vote(PMV) index shows that a set temperature of 27 ℃,not 26 ℃,is sufficiently comfortable for office staff wearing long-sleeve shirts,long pants and leather shoes.
基金Supported by Key Laboratory of Condition Monitoring and Control for Power Plant Equipment of Ministry of Education of China
文摘Variable-air-volume (VAV) air-conditioning system is a multi-variable system and has multi coupling control loops. While all of the control loops are working together, they interfere and influence each other. A multivariable decoupling PID controller is designed for VAV air-conditioning system. Diagonal matrix decoupling method is employed to eliminate the coupling between the loop of supply air temperature and that of thermal-space air temperature. The PID controller parameters are optimized by means of an improved genetic algorithm in floating point representations to obtain better performance. The population in the improved genetic algorithm mutates before crossover, which is helpful for the convergence. Additionally the micro mutation algorithm is proposed and applied to improve the convergence during the later evolution. To search the best parameters, the optimized parameters ranges should be amplified 10 times the initial ideal parameters. The simulation and experiment results show that the decoupling control system is effective and feasible. The method can overcome the strong coupling feature of the system and has shorter governing time and less over-shoot than non-optimization PID control.
文摘BACKGROUND Four-liter polyethylene glycol(PEG)solutions are effective for bowel cleansing,but their large volume might hinder patient compliance.Due to the unique features of Asians,4 L PEG might be a suboptimal bowel preparation in predominantly ethnically Asian countries.In view of this,a balance should be achieved between the volume and effectiveness.The ideal bowel cleansing regimen for a colonoscopy has yet to be determined in a Chinese population.AIM To compare the cleansing efficacy of 3 L PEG plus simethicone with 4 L PEG.METHODS A total of 291 patients were randomly allocated to two groups:Group 1(n=145)received 4 L split-dose PEG(4-P);group 2(n=146)received 3 L split-dose PEG plus simethicone(3-PS).Bowel-cleansing efficacy was evaluated by endoscopists using the Boston bowel preparation scale(BBPS)and the bubbles score.RESULTS Although there were no significant differences in the total BBPS score or the adequate rate of bowel preparation between the two groups,the BBPS score of the right-side colon was significantly higher in the 3-SP group(2.37±0.54 vs 2.21±0.78;P=0.04).Moreover,the use of simethicone significantly reduced bubbles in all colon segments(P<0.001).The mean withdrawal time was significantly shorter in the 3-PS group(8.8±3.4 vs 9.6±2.3;P=0.02).Furthermore,significantly more proximal adenomas were detected in the 3-PS group(53.6%vs 45.7%;P=0.03).In addition,the proportions of patients with nausea and bloating were significantly lower in the 3-SP group(P<0.01 for both).More patients in the 3-PS group expressed willingness to repeat the bowel preparation(87.7%vs 76.6%,P=0.01).CONCLUSION Three-liter PEG shows satisfactory bowel cleansing despite the decrease in dosage,and addition of simethicone with better bubble elimination and enhanced patient acceptance offers excellent potential impact on the detection of proximal adenomas in Chinese patients.
基金supported by the National Natural Science Foundations of China (Nos. 61861136005,61851110763,and 71731001).
文摘As the rapid development of aviation industry and newly emerging crowd-sourcing projects such as Flightradar24 and FlightAware,large amount of air traffic data,particularly four-dimension(4D)trajectory data,have become available for the public.In order to guarantee the accuracy and reliability of results,data cleansing is the first step in analyzing 4D trajectory data,including error identification and mitigation.Data cleansing techniques for the 4D trajectory data are investigated.Back propagation(BP)neural network algorithm is applied to repair errors.Newton interpolation method is used to obtain even-spaced trajectory samples over a uniform distribution of each flight’s 4D trajectory data.Furthermore,a new method is proposed to compress data while maintaining the intrinsic characteristics of the trajectories.Density-based spatial clustering of applications with noise(DBSCAN)is applied to identify remaining outliers of sample points.Experiments are performed on a data set of one-day 4D trajectory data over Europe.The results show that the proposed method can achieve more efficient and effective results than the existing approaches.The work contributes to the first step of data preprocessing and lays foundation for further downstream 4D trajectory analysis.
文摘Surfactant, an abbreviation for the surface-active agent, is utilized in almost every industry. It brings two immiscible phases such as oil and water into one single homogeneous phase, leading to various industrial applications such as food, painting, coating, drug delivery as well as cosmetics. The use of surfactants in skin cleansing is very common to keep skin healthy. Their function herein is to lower the interfacial tension at the dirt/water and skin/water interfaces, thereby detaching dirt, extra sebum or oils from the skin surface. But this application could bring side effects attributed to the penetration of surfactants into the skin, including skin proteins denaturation, stratum corneum lipids removal or even lipids organization disruption in the stratum corneum. This review summarizes modern mild skin cleansing technologies, which address the side effects brought by the surfactants.
文摘Two building factors-a longer thermal lag of more than one hour for building envelops and a lag of indoor radiation to convert into cooling load-have impact on the instantaneous heat input and instantaneous cooling load.So the two factors should be taken into account when selecting the weather parameters for air-conditioning system design.This paper developed a new statistic method for the rational selection of coincident solar irradiance,dry-bulb and wet-bulb temperatures.The method was applied to historic weather records of 25 years in Hong Kong to generate coincident design weather data.And the results show that traditional design solar irradiance,dry-bulb and wet-bulb temperatures may be significantly overestimated in many conditions,and the design weather data for the three different constructions is not kept constant.
基金Beijing Science and Technology Program,China,Early Endoscopic Diagnosis for Colorectal Cancer—The Guidance Study,No.D17110002617002.
文摘BACKGROUND Research data from patient reports indicate that the least bearable part of colonoscopy is the administration of laxatives for bowel preparation.AIM To observe the intestinal cleansing efficacy and safety of sodium picosulfate/magnesium citrate and to discuss the patients’experiences due to the procedure.METHODS Subjects hospitalized in the International Medical Center Ward of Peking University International Hospital,Beijing,China,from April 29 to October 29,2020,for whom the colonoscopy was planned,were enrolled.Bowel preparation was performed using sodium picosulfate/magnesium citrate.The effect of bowel cleansing was evaluated according to the Ottawa Bowel Preparation Scale,defecation conditions and adverse reactions were recorded,and the comfort level and subjective satisfaction concerning medication were evaluated by the visual analogue scale/score(VAS).RESULTS The bowel preparation procedure was planned for all patients enrolled,which included 42 males and 22 females.The results showed an average liquid rehydration volume of 3000 mL,an average onset of action for the first dose at 89.04 min,an average number of bowel movements of 4.3 following the first dose,an average onset of action for the second dose at 38.90 min and an average number of bowel movements of 5.0 after the second dose.The total average Ottawa Bowel Preparation Scale score was 3.6,with 93.55%of bowel preparations in the“qualified”and 67.74%in the“excellent”grade.The average VAS score of effect on sleep was 0,and the average VAS score of perianal pain was also 0.The average VAS score for ease of taking and taste perception of the bowel cleanser was 10.Side effects included mild to moderate nausea(15.63%),mild vomiting(4.69%),mild to moderate abdominal pain(7.81%),mild to moderate abdominal distension(20.31%),mild palpitation(7.81%)and mild dizziness(4.69%).CONCLUSION Sodium picosulfate/magnesium citrate is effective and safe for bowel preparation before colonoscopy with high subjective patient acceptance,thus improving overall patient compliance.
文摘The aim of this research was to study and design a solid desiccant dehumidification system suitable for tropical climate to reduce the latent load of air-conditioning system and improve the thermal comfort. Different dehumidifiers such as desiccant column and desiccant wheel were investigated. The ANSYS and TRASYS software were used to predict the results of dehumidifiers and the desiccant cooling systems, respectively. The desiccant bed contained approximately 15 kg of silica-gel, with 3 mm average diameter. Results indicated that the pressure drop and the adsorption rate of desiccant column are usually higher than those of the desiccant wheel. The feasible and practical adsorption rate of desiccant wheel was 0.102 kgw/h at air flow rate 1.0 kg/min, regenerated air temperature of 55?C and at a wheel speed of 2.5 rpm. The humidity ratio of conditioning space and cooling load of split-type air conditioner was decreased to 0.002 kgw/kgda (14%) and 0.71 kWth (19.26%), respectively. Consequently, the thermal comfort was improved from 0.5 PMV (10.12% PPD) to 0.3 PMV (7.04% PPD).
文摘An energy-saving control strategy based on predictive control for central air-conditioning systems is proposed in this paper. The cold load model is developed to describe the dynamic characteristics of temperature control systems, and then parameters in the cold load model and in the central air-conditioning system model are estimated. Generalized predictive control (GPC) is used to establish an optimization model to minimize the consumption of energy and the control error of temperature. The simulated annealing (SA) algorithm, combined with quadratic programming, is adopted to solve the optimal problem. Contrasted with the simulation of traditional PID control, the results prove the effectiveness of this proposed strategy.
文摘As the conceptual design of air-conditioning is done using the theory of Quality Function Deployment (QFD),cus- tomer requirements should be understood and the product competitive power be analyzed as exactly as possible for new product de- signing.Lots of information in the process of this research is fuzzy and uncertain,but traditional QFD can not deal with it well. Fuzzy theory can solve the problem.So a fuzzy model for analyzing product competitive power is formulated in this paper to im- prove traditional QFD,after that it is applied to analyze air-conditioning competitive power.When air-conditioning competitive power is analyzed using this model,firstly the importance weight of the customer requirements o fair-conditioning is determined us- ing the Analytic Hierarchy Process (AHP) weighting process,then air-conditloning competitive power is evaluated using fuzzy comprehensive evaluation.It is proved that the model is feasible and has good applicability.
文摘Colonoscopy is a crucial diagnostic instrument for colorectal cancer screening and an adequate bowel preparation is definitely decisive for the success of the procedure. Especially in elderly patients, bowel cleansing is considered a big issue, because it is often poorly tolerated for many reasons(like inability to swallow large volume of liquids or unlikable taste); this can cause a suboptimal preparation that may lead to miss a neoplastic lesion. There is relatively little data about how to improve preparation tolerability. The purpose of our pilot study was to analyze the effect of prucalopride(Resolor~?), a highly selective serotonin 5HT4 receptor agonist used for chronic constipation for its ability to stimulate gastrointestinal peristalsis, undertaken the day before colonoscopy, followed by half volume of polyethylene glycol solution. We found that this can be a good and safe method to achieve an adequate and better-tolerated colon cleansing.
基金Supported by the National Basic Research Program of China("973"Program,No.2009CB219907)
文摘An explosion-proof dual throttling air-conditioning system was put forward to solve the heat dissipation and internal dewing problems of explosion-proof frequency converter in the underground coal mine. This study investigated the feasibility and benefits of explosion-proof dual throttling cooling and dehumidification air-conditioning system applied to the explosion-proof frequency converter. The physical model of dual throttling air-conditioning system was established and its performance parameter was described by mathematical method. The design calculation of the system has also been done. The experimental result showed that the system reached the steady state at the refrigeration mode after running 45 min, and the maximum internal temperature of the flame-proof cavity was 31.0 ℃. The system reached the steady state at the dehumidification mode after running 37 min. The maximum internal relative humidity and temperature of the flame-proof cavity were 33.4% and 36.3 ℃, respectively. Therefore, the proposed system had excellent ability of heat dissipation and avoided internal dewing. Compared with water cooling system, it was more energy-saving and economical. The airflow field of dual throttling air-conditioning system was also studied by CFD simulation. It was found that the result of CFD numerical simulation was highly consistent with the experimental data.
文摘The artificial intelligence is applied to the simulation of the automotive air-conditioning system ( AACS )According to the system's characteristics a model of AACS, based on neural network, is developed. Different control methods of AACS are discussed through simulation based on this model. The result shows that the neural- fuzzy control is the best one compared with the on-off control and conventional fuzzy control method.It can make the compartment's temperature descend rapidly to the designed temperature and the fluctuation is small.