The stability of the subsea oil and gas production system is heavily influenced by slug flow. One successful method of managing slug flow is to use top valve control based on subsea pipeline pressure. However, the com...The stability of the subsea oil and gas production system is heavily influenced by slug flow. One successful method of managing slug flow is to use top valve control based on subsea pipeline pressure. However, the complexity of production makes it difficult to measure the pressure of subsea pipelines, and measured values are not always accessible in real-time. The research introduces a technique for integrating Unscented Kalman Filter (UKF) and Wavelet Neural Network (WNN) to estimate the state of subsea pipeline pressure using historical data and a state model. The proposed method treats multiphase flow transport as a nonlinear model, with a dynamic WNN serving as the state observer. To achieve real-time state estimation, the WNN is included into the UKF algorithm to create a WNN-based UKF state equation. Integrate WNN and UKF in a novel way to predict system state accurately. The simulated results show that the approach can efficiently predict the inlet pressure and manage the slug flow in real-time using the riser's top pressure, outlet flow and valve opening. This method of estimate can significantly increase the control effect.展开更多
In an integrated energy system(IES) composed of multiple subsystems, energy coupling causes an energy supply blockage or shutdown in one subsystem, thereby affecting the energy flow distribution optimization of other ...In an integrated energy system(IES) composed of multiple subsystems, energy coupling causes an energy supply blockage or shutdown in one subsystem, thereby affecting the energy flow distribution optimization of other subsystems.The energy supply should be globally optimized during the IES energy supply restoration process to produce the highest restoration net income. Mobile emergency sources can be quickly and flexibly connected to supply energy after an energy outage to ensure a reliable supply to the system, which adds complexity to the decision. This study focuses on a powergas IES with mobile emergency sources and analyzes the coupling relationship between the gas distribution system and the power distribution system in terms of sources, networks, and loads, and the influence of mobile emergency source transportation. The influence of the transient process caused by the restoration operation of the gas distribution system on the power distribution system is also discussed. An optimization model for power-gas IES restoration was established with the objective of maximizing the net income. The coordinated restoration optimization decision-making process was also built to realize the decoupling iteration of the power-gas IES, including system status recognition, mobile emergency source dispatching optimization, gas-to-power gas flow optimization, and parallel intra-partition restoration scheme optimization for both the power and gas distribution systems. A simulation test power-gas IES consisting of an 81-node medium-voltage power distribution network, an 89-node medium-pressure gas distribution network, and four mobile emergency sources was constructed. The simulation analysis verified the efficiency of the proposed coordinated restoration optimization method.展开更多
The dynamic traveling salesman problem(DTSP)is significant in logistics distribution in real-world applications in smart cities,but it is uncertain and difficult to solve.This paper proposes a scheme library-based ant...The dynamic traveling salesman problem(DTSP)is significant in logistics distribution in real-world applications in smart cities,but it is uncertain and difficult to solve.This paper proposes a scheme library-based ant colony optimization(ACO)with a two-optimization(2-opt)strategy to solve the DTSP efficiently.The work is novel and contributes to three aspects:problemmodel,optimization framework,and algorithmdesign.Firstly,in the problem model,traditional DTSP models often consider the change of travel distance between two nodes over time,while this paper focuses on a special DTSP model in that the node locations change dynamically over time.Secondly,in the optimization framework,the ACO algorithm is carried out in an offline optimization and online application framework to efficiently reuse the historical information to help fast respond to the dynamic environment.The framework of offline optimization and online application is proposed due to the fact that the environmental change inDTSPis caused by the change of node location,and therefore the newenvironment is somehowsimilar to certain previous environments.This way,in the offline optimization,the solutions for possible environmental changes are optimized in advance,and are stored in a mode scheme library.In the online application,when an environmental change is detected,the candidate solutions stored in the mode scheme library are reused via ACO to improve search efficiency and reduce computational complexity.Thirdly,in the algorithm design,the ACO cooperates with the 2-opt strategy to enhance search efficiency.To evaluate the performance of ACO with 2-opt,we design two challenging DTSP cases with up to 200 and 1379 nodes and compare them with other ACO and genetic algorithms.The experimental results show that ACO with 2-opt can solve the DTSPs effectively.展开更多
With the concurrent consumption of herbal medicines and conventional drugs,herb-drug interactions(HDIs)have become the most important clinical consequence of this practice.A general overview and the significance of ph...With the concurrent consumption of herbal medicines and conventional drugs,herb-drug interactions(HDIs)have become the most important clinical consequence of this practice.A general overview and the significance of pharmacokinetic and pharmacodynamic HDIs are provided,detailing basic mechanism,especially the metabolic enzymes and drug transporters,such as CYP450 and P-gp.展开更多
AIM:To evaluate the predictive value of preoperative predictors for portal vein thrombosis(PVT)after splenectomy with periesophagogastric devascularization.METHODS:In this prospective study,69 continuous patients with...AIM:To evaluate the predictive value of preoperative predictors for portal vein thrombosis(PVT)after splenectomy with periesophagogastric devascularization.METHODS:In this prospective study,69 continuous patients with portal hypertension caused by hepatitis B cirrhosis underwent splenectomy with periesophagogastric devascularization in West China Hospital of Sichuan University from January 2007 to August 2010.The portal vein flow velocity and the diameter of portal vein were measured by Doppler sonography.The hepatic congestion index and the ratio of velocity and diameter were calculated before operation.The prothrombin time(PT)and platelet(PLT)levels were measured before and after operation.The patients'spleens were weighed postoperatively.RESULTS:The diameter of portal vein was negatively correlated with the portal vein flow velocity(P<0.05).Thirty-three cases(47.83%)suffered from postoperative PVT.There was no statistically significant difference in the Child-Pugh score,the spleen weights,the PT,or PLT levels between patients with PVT and without PVT.Receiver operating characteristic curves showed four variables(portal vein flow velocity,the ratio of velocity and diameter,hepatic congestion index and diameter of portal vein)could be used as preoperative predictors of postoperative portal vein thrombosis.The respective values of the area under the curve were 0.865,0.893,0.884 and 0.742,and the respective cut-off values(24.45 cm/s,19.4333/s,0.1138 cm/s-1 and 13.5 mm) were of diagnostically efficient,generating sensitivity values of 87.9%,93.9%,87.9%and 81.8%,respectively,specificities of 75%,77.8%,86.1%and 63.9%,respectively.CONCLUSION:The ratio of velocity and diameter was the most accurate preoperative predictor of portal vein thrombosis after splenectomy with periesophagogastric devascularization in hepatitis B cirrhosis-related portal hypertension.展开更多
AIM:To identify factors related to serious postoperative bacterial and fungal infections in the first 3 mo after living donor liver transplantation(LDLT).METHODS:In the present study,the data of 207 patients from 2004...AIM:To identify factors related to serious postoperative bacterial and fungal infections in the first 3 mo after living donor liver transplantation(LDLT).METHODS:In the present study,the data of 207 patients from 2004 to 2011 were reviewed.The pre-,intra-and post-operative factors were statistically analyzed.All transplantations were approved by the ethics committee of West China Hospital,Sichuan University.Patients with definitely preoperative infections and infections within 48 h after transplantation were excluded from current study.All potential risk factors were analyzed using univariate analyses.Factors significant at a P < 0.10 in the univariate analyses were involved in the multivariate analyses.The diagnostic accuracy of the identified risk factors was evaluated using receiver operating curve.RESULTS:The serious bacterial and fungal infection rates were 14.01% and 4.35% respectively.Enterococcus faecium was the predominant bacterial pathogen,whereas Candida albicans was the most common fungal pathogen.Lung was the most common infection site for both bacterial and fungal infections.Recipient age older than 45 years,preoperative hyponatremia,intensive care unit stay longer than 9 d,postoperative bile leak and severe hyperglycemia were independent risk factors for postoperative bacterial infection.Massive red blood cells transfusion and postoperative bacterial infection may be related to postoperative fungal infection.CONCLUSION:Predictive risk factors for bacterial and fungal infections were indentified in current study.Pre-,intra-and post-operative factors can cause postoperative bacterial and fungal infections after LDLT.展开更多
Squamous cell carcinoma (SCC) is a significant cause of cancer morbidity and mortality worldwide, with an incidence of up to 166 cases per 100 000 population. It arises in the skin, upper aerodigestive tract, lung, an...Squamous cell carcinoma (SCC) is a significant cause of cancer morbidity and mortality worldwide, with an incidence of up to 166 cases per 100 000 population. It arises in the skin, upper aerodigestive tract, lung, and cervix and affects more than 200 000 Americans each year. We report here that a microarray experiment comparing 41 SCC and 13 normal tissue specimens showed that Id2, a gene that controls the cell cycle, was significantly up-regulated in SCC. Enforced expression of Id2 in vitro stimulated the proliferation of SCC cells and up-regulated the transcription of nuclear factor kappa B (NF-κB) and cyclin D1. Enhancement of the NF-κB activity with p65 significantly increased the cell proliferation and the transcription of cyclin D1, whereas inhibition of the NF-κB activity with I kappa B alpha mutant (IκBα M) and pyrroline dithiocarbamate (PDTC) abrogated cell proliferation and transcription of cyclin D1. Furthermore, a mutated NF-κB binding site in the cyclin D1 promoter fully abrogated the Id2-induced transcription of cyclin D1. Taken together, these data indicate that Id2 induces SCC tumor growth and proliferation through the NF-κB/cyclin D1 pathway.展开更多
A type of calcium coke was developed for use in the oxy-thermal process of calcium carbide production.The calcium coke was prepared by the co-pyrolysis of coking coal and calcium carbide slag, which is a solid waste g...A type of calcium coke was developed for use in the oxy-thermal process of calcium carbide production.The calcium coke was prepared by the co-pyrolysis of coking coal and calcium carbide slag, which is a solid waste generated from the chlor-alkali industry.The characteristics of the calcium cokes under different conditions were analyzed experimentally and theoretically.The results show that the thermal strength of calcium coke increased with the increase in the coking coal proportion, and the waterproof property of calcium coke also increased with increased carbonation time.The calcium coke can increase the contact area of calcium and carbon in the calcium carbide production process.Furthermore, the pore structure of the calcium coke can enhance the diffusion of gas inside the furnace, thus improving the efficiency of the oxy-thermal technology.展开更多
AIM: To investigate the role of single nucleotide polymorphisms(SNPs) in CD24 gene in susceptibility and overall survival of gastric cancer(GC).METHODS: We genotyped 3 tagging SNPs of CD24-P-534 in the promoter region...AIM: To investigate the role of single nucleotide polymorphisms(SNPs) in CD24 gene in susceptibility and overall survival of gastric cancer(GC).METHODS: We genotyped 3 tagging SNPs of CD24-P-534 in the promoter region, P170 in the coding region of exon 2 and P1527 in the 3′ untranslated region- using polymerase chain reaction-restriction fragment length polymorphism in specimens from 679 histologically-confirmed GC cases, 111 gastric atrophy(GA) cases and 976 tumor-free controls. Serumimmunoglobulin G antibodies to Helicobacter pylori(H. pylori) of all subjects were detected by enzyme-linked immunosorbent assay. CD24 expression was evaluated by immunohistochemistry in 131 GC specimens. Correlations between SNPs and risk of GC or GA were shown by P values and odd ratios(ORs) with 95% confidence intervals(95%CI) compared with the most common genotype of each SNP using the unconditional logistic regression model after adjusting for age, sex and H. pylori infection. Survival within each SNP group was plotted by Kaplan-Meier method and compared by log-rank test(recessive model). Hazard ratios with 95%CIs were computed by Cox regression model after adjusting for age, sex, histological type, tumor differentiation, clinical stage and post-operational chemotherapy.RESULTS: All of the three loci were in Hardy-Weinberg equilibrium in the control group. Median followup time for the 600 GC patients included in the survival analysis was 36.2 mo(range, 2.1-66.7 mo; 95%CI: 34.3-36.5 mo). Patients with the P-534 A/A genotype had significantly shorter survival(HR = 1.38, 95%CI: 1.01-1.88, P = 0.042) than did the C/C or C/A genotype carriers after adjusting for age, sex, histological type, tumor differentiation, clinical stage and post-operational chemotherapy. This trend was more evident in patients who lived longer than 2.5 years(HR = 7.55, 95%CI: 2.16-26.32, P = 0.001). The P170 T/T genotype was associated with a shorter lifespan than the non-T/T genotypes, but not significantly so. None of the three genetic variants was found to be associated with risk of GC(including tumor stage, grade and distant metastasis) or with risk of gastric atrophy. Furthermore, no difference of CD24 expression was found among the genotypes.CONCLUSION: The P-534 site in CD24 gene affects the overall survival of gastric cancer and may serve as a prognostic marker for gastric cancer.展开更多
Conjugated polymers are commonly used as effective hole transport materials(HTMs) for preparation of high-performance perovskite solar cells. However, the hydrophobic nature of these materials renders it difficult to ...Conjugated polymers are commonly used as effective hole transport materials(HTMs) for preparation of high-performance perovskite solar cells. However, the hydrophobic nature of these materials renders it difficult to deposit photovoltaic perovskite layers on top via solution processing. In this article, we report a generic surface modification strategy that enables the deposition of uniform and dense perovskite films on top of non-wetting interfaces. In contrast to the previous proposed chemical modifications which might alter the optoelectronic properties of the interfacial layers, we realized a nondestructive surface modification enabled by introducing a layer of insulating mesoporous aluminum oxide(Al2O3). The surface energies of the typical non-wetting hole-transport layers(PTAA, P3 HT, and Poly-TPD) were significantly reduced by the Al2O3 modification. Benefiting from the intact optoelectronic properties of the HTMs, perovskite solar cells deposited on these interface materials show full open-circuit voltages( V OC) with high fill factors(FF) up to 80%. Our method provides an effective avenue for exploiting the full potential of the existing as well as newly developed non-wetting interface materials for the fabrication of high-performance inverted perovskite solar cells.展开更多
This paper focuses on anisotropy of coal permeability and its stress sensitivity.Coal blocks were taken from Xinjing Coal Mine in Yangquan Coal District.Coal cores were then drilled along the strike,dip,and vertical d...This paper focuses on anisotropy of coal permeability and its stress sensitivity.Coal blocks were taken from Xinjing Coal Mine in Yangquan Coal District.Coal cores were then drilled along the strike,dip,and vertical directions.Coal permeabilities were measured with respect to stress by using a self-developed coal permeability measurement system.The used samples exhibited significant permeability anisotropy.The permeability along the strike direction was greatest among the three directions,the permeability along the vertical direction was the smallest,and the permeability along the dip direction was between the other two directions.The sensitivity of coal permeability to stress was transversely isotropic.The stress sensitivity coefficient was greater along the horizontal directions than along the vertical directions.Coal permeability exhibited anisotropic stress sensitivity due to anisotropy in Young’s modulus and porosity.The results obtained in this study are useful for optimizing the arrangement of pre-drainage boreholes.展开更多
Combustion kinetics of the hydrochar was investigated using a multi-Gaussian-distributed activation energy model(DAEM)to ex-pand the knowledge on the combustion mechanisms.The results demonstrated that the kinetic par...Combustion kinetics of the hydrochar was investigated using a multi-Gaussian-distributed activation energy model(DAEM)to ex-pand the knowledge on the combustion mechanisms.The results demonstrated that the kinetic parameters calculated by the multi-Gaussian-DAEM accurately represented the experimental conversion rate curves.Overall,the feedstock combustion could be divided into four stages:the decomposition of hemicellulose,cellulose,lignin,and char combustion.The hydrochar combustion could in turn be divided into three stages:the combustion of cellulose,lignin,and char.The mean activation energy ranges obtained for the cellulose,lignin,and char were 273.7-292.8,315.1-334.5,and 354.4-370 kJ/mol,respectively,with the standard deviations of 2.1-23.1,9.5-27.4,and 12.1-22.9 kJ/mol,re-spectively.The cellulose and lignin contents first increased and then decreased with increasing hydrothermal carbonization(HTC)temperature,while the mass fraction of char gradually increased.展开更多
Kawasaki disease(KD)is an acute systemic vasculitis characterized by unknown etiology.CASE SUMMARY A 4.5-year-old boy developed an acute abdomen during the onset of incomplete KD.He still had persistent abdominal pain...Kawasaki disease(KD)is an acute systemic vasculitis characterized by unknown etiology.CASE SUMMARY A 4.5-year-old boy developed an acute abdomen during the onset of incomplete KD.He still had persistent abdominal pain after undergoing exploratory laparotomy and appendectomy.Ultrasound examination at early onset revealed a giant coronary artery aneurysm.The patient developed a myocardial infarction and heart failure accompanied by respiratory and cardiac arrest.He underwent coronary artery revascularization and coronary artery bypass graft using an autologous internal mammary artery.After the operation,the cardiac output increased,and the symptoms of heart failure resolved.Follow-up evaluation at 1 mo after operation showed that the patient's cardiac function had restored to New York Heart Association standard Grade I heart failure,and normal growth was obtained.CONCLUSION Coronary artery revascularization and coronary artery bypass graft is an effective method for treating myocardial ischemia in children with KD complicated with giant coronary artery aneurysm.Nevertheless,some issues still need specific attention.展开更多
The recent development on wearable and stretchable electronics calls for skin conformable power sources that are beyond current battery technologies.Among the many novel energy devices being explored,triboelectric nan...The recent development on wearable and stretchable electronics calls for skin conformable power sources that are beyond current battery technologies.Among the many novel energy devices being explored,triboelectric nanogenerator(TENG)made from intrinsically stretchable materials has a great potential to meet the above requirement as being both soft and efficient.In this paper,we present a lithography-free and low-cost TENG device comprising a porous-structured PDMS layer and a stretchable PEDOT:PSS electrode.The porous PDMS structure is formed by using self-assembled polystyrene beads as the sacrificial template and it is highly ordered with great uniformity and high structural stability under compression force.Moreover,the porous PDMS TENG exhibits improved output voltage and current of 1.65 V and 0.54 nA compared to its counterpart with non-porous PDMS with 0.66 V and 0.34 nA.The effect of different loading force and frequency on the output response of the TENG device has also been studied.This work could shed light on diverse structural modification methods for improving the performance of PDMS-based TENG and the development of intrinsically stretchable TENG for wearable device applications.展开更多
The fault current limiter(FCL)is an effective measure for improving system stability and suppressing short-circuit fault current.Because of space and economic costs,the optimum placement of FCLs is vital in industrial...The fault current limiter(FCL)is an effective measure for improving system stability and suppressing short-circuit fault current.Because of space and economic costs,the optimum placement of FCLs is vital in industrial applications.In this study,two objectives with the same dimensional measurement unit,namely,the total capital investment cost of FCLs and circuit breaker loss related to short-circuit currents,are considered.The circuit breaker loss model is developed based on the attenuation rule of the circuit breaker service life.The circuit breaker loss is used to quantify the current-limiting effect to avoid the problem of weight selection in a multi-objective problem.The IEEE 10-generator 39-bus system in New England is used to evaluate the performance of the proposed genetic algorithm(GA)method.Comparative and sensitivity analyses are performed.The results of the optimized plan are validated through simulations,indicating the significant potential of the GA for such optimization.展开更多
Flexible and wearable sensors that can acquire signals of pressure,temperature,optical input,chemical environment as well as human body physiological and biological parameters,are of critical importance for robotics a...Flexible and wearable sensors that can acquire signals of pressure,temperature,optical input,chemical environment as well as human body physiological and biological parameters,are of critical importance for robotics and health,in which these sensors are hence in urgent demands.On the fundamental side,there are still substantial challenges on how to design and fabricate materials with biocompatibility,robustness and excellent mechanical flexibility,as well as to achieve sensor devices with high performance,low power consumption and good system integration capability.Meanwhile in practical applications,there are also obstacles on the integration of various kinds of sensors with flexible substrates,signal processing and power supply units.With the fast development of Internet of Things(IoT),smart sensors will as well be interconnected to form sensor networks,providing big data for our future intelligent living.All these would deliver a profound socioeconomic impact to our society.展开更多
基金supported by Development Project in Key Technical Field of Sichuan Province(2019ZDZX0030)International Science and Technology Innovation Cooperation Program of Sichuan Province(2021YFH0115)+1 种基金Nanchong-SWPU Science and Technology Strategic Cooperation Project(SXHZ057)Key and Core Technology Breakthrough Project of CNPC(2021ZG08).
文摘The stability of the subsea oil and gas production system is heavily influenced by slug flow. One successful method of managing slug flow is to use top valve control based on subsea pipeline pressure. However, the complexity of production makes it difficult to measure the pressure of subsea pipelines, and measured values are not always accessible in real-time. The research introduces a technique for integrating Unscented Kalman Filter (UKF) and Wavelet Neural Network (WNN) to estimate the state of subsea pipeline pressure using historical data and a state model. The proposed method treats multiphase flow transport as a nonlinear model, with a dynamic WNN serving as the state observer. To achieve real-time state estimation, the WNN is included into the UKF algorithm to create a WNN-based UKF state equation. Integrate WNN and UKF in a novel way to predict system state accurately. The simulated results show that the approach can efficiently predict the inlet pressure and manage the slug flow in real-time using the riser's top pressure, outlet flow and valve opening. This method of estimate can significantly increase the control effect.
基金supported by the Open Research Fund of Jiangsu Collaborative Innovation Center for Smart Distribution Network (XTCX202001)National Natural Science Foundation of China (52077061)。
文摘In an integrated energy system(IES) composed of multiple subsystems, energy coupling causes an energy supply blockage or shutdown in one subsystem, thereby affecting the energy flow distribution optimization of other subsystems.The energy supply should be globally optimized during the IES energy supply restoration process to produce the highest restoration net income. Mobile emergency sources can be quickly and flexibly connected to supply energy after an energy outage to ensure a reliable supply to the system, which adds complexity to the decision. This study focuses on a powergas IES with mobile emergency sources and analyzes the coupling relationship between the gas distribution system and the power distribution system in terms of sources, networks, and loads, and the influence of mobile emergency source transportation. The influence of the transient process caused by the restoration operation of the gas distribution system on the power distribution system is also discussed. An optimization model for power-gas IES restoration was established with the objective of maximizing the net income. The coordinated restoration optimization decision-making process was also built to realize the decoupling iteration of the power-gas IES, including system status recognition, mobile emergency source dispatching optimization, gas-to-power gas flow optimization, and parallel intra-partition restoration scheme optimization for both the power and gas distribution systems. A simulation test power-gas IES consisting of an 81-node medium-voltage power distribution network, an 89-node medium-pressure gas distribution network, and four mobile emergency sources was constructed. The simulation analysis verified the efficiency of the proposed coordinated restoration optimization method.
基金supported in part by the National Research Foundation of Korea (NRF-2021H1D3A2A01082705).
文摘The dynamic traveling salesman problem(DTSP)is significant in logistics distribution in real-world applications in smart cities,but it is uncertain and difficult to solve.This paper proposes a scheme library-based ant colony optimization(ACO)with a two-optimization(2-opt)strategy to solve the DTSP efficiently.The work is novel and contributes to three aspects:problemmodel,optimization framework,and algorithmdesign.Firstly,in the problem model,traditional DTSP models often consider the change of travel distance between two nodes over time,while this paper focuses on a special DTSP model in that the node locations change dynamically over time.Secondly,in the optimization framework,the ACO algorithm is carried out in an offline optimization and online application framework to efficiently reuse the historical information to help fast respond to the dynamic environment.The framework of offline optimization and online application is proposed due to the fact that the environmental change inDTSPis caused by the change of node location,and therefore the newenvironment is somehowsimilar to certain previous environments.This way,in the offline optimization,the solutions for possible environmental changes are optimized in advance,and are stored in a mode scheme library.In the online application,when an environmental change is detected,the candidate solutions stored in the mode scheme library are reused via ACO to improve search efficiency and reduce computational complexity.Thirdly,in the algorithm design,the ACO cooperates with the 2-opt strategy to enhance search efficiency.To evaluate the performance of ACO with 2-opt,we design two challenging DTSP cases with up to 200 and 1379 nodes and compare them with other ACO and genetic algorithms.The experimental results show that ACO with 2-opt can solve the DTSPs effectively.
文摘With the concurrent consumption of herbal medicines and conventional drugs,herb-drug interactions(HDIs)have become the most important clinical consequence of this practice.A general overview and the significance of pharmacokinetic and pharmacodynamic HDIs are provided,detailing basic mechanism,especially the metabolic enzymes and drug transporters,such as CYP450 and P-gp.
基金Supported by Grants from the Sichuan Provincial scientific and technological supported project,No.2009sz0172
文摘AIM:To evaluate the predictive value of preoperative predictors for portal vein thrombosis(PVT)after splenectomy with periesophagogastric devascularization.METHODS:In this prospective study,69 continuous patients with portal hypertension caused by hepatitis B cirrhosis underwent splenectomy with periesophagogastric devascularization in West China Hospital of Sichuan University from January 2007 to August 2010.The portal vein flow velocity and the diameter of portal vein were measured by Doppler sonography.The hepatic congestion index and the ratio of velocity and diameter were calculated before operation.The prothrombin time(PT)and platelet(PLT)levels were measured before and after operation.The patients'spleens were weighed postoperatively.RESULTS:The diameter of portal vein was negatively correlated with the portal vein flow velocity(P<0.05).Thirty-three cases(47.83%)suffered from postoperative PVT.There was no statistically significant difference in the Child-Pugh score,the spleen weights,the PT,or PLT levels between patients with PVT and without PVT.Receiver operating characteristic curves showed four variables(portal vein flow velocity,the ratio of velocity and diameter,hepatic congestion index and diameter of portal vein)could be used as preoperative predictors of postoperative portal vein thrombosis.The respective values of the area under the curve were 0.865,0.893,0.884 and 0.742,and the respective cut-off values(24.45 cm/s,19.4333/s,0.1138 cm/s-1 and 13.5 mm) were of diagnostically efficient,generating sensitivity values of 87.9%,93.9%,87.9%and 81.8%,respectively,specificities of 75%,77.8%,86.1%and 63.9%,respectively.CONCLUSION:The ratio of velocity and diameter was the most accurate preoperative predictor of portal vein thrombosis after splenectomy with periesophagogastric devascularization in hepatitis B cirrhosis-related portal hypertension.
基金Supported by The National Science and Technology Major Project of China,No.2012ZX10002-016 and 2012ZX10002017-006
文摘AIM:To identify factors related to serious postoperative bacterial and fungal infections in the first 3 mo after living donor liver transplantation(LDLT).METHODS:In the present study,the data of 207 patients from 2004 to 2011 were reviewed.The pre-,intra-and post-operative factors were statistically analyzed.All transplantations were approved by the ethics committee of West China Hospital,Sichuan University.Patients with definitely preoperative infections and infections within 48 h after transplantation were excluded from current study.All potential risk factors were analyzed using univariate analyses.Factors significant at a P < 0.10 in the univariate analyses were involved in the multivariate analyses.The diagnostic accuracy of the identified risk factors was evaluated using receiver operating curve.RESULTS:The serious bacterial and fungal infection rates were 14.01% and 4.35% respectively.Enterococcus faecium was the predominant bacterial pathogen,whereas Candida albicans was the most common fungal pathogen.Lung was the most common infection site for both bacterial and fungal infections.Recipient age older than 45 years,preoperative hyponatremia,intensive care unit stay longer than 9 d,postoperative bile leak and severe hyperglycemia were independent risk factors for postoperative bacterial infection.Massive red blood cells transfusion and postoperative bacterial infection may be related to postoperative fungal infection.CONCLUSION:Predictive risk factors for bacterial and fungal infections were indentified in current study.Pre-,intra-and post-operative factors can cause postoperative bacterial and fungal infections after LDLT.
文摘Squamous cell carcinoma (SCC) is a significant cause of cancer morbidity and mortality worldwide, with an incidence of up to 166 cases per 100 000 population. It arises in the skin, upper aerodigestive tract, lung, and cervix and affects more than 200 000 Americans each year. We report here that a microarray experiment comparing 41 SCC and 13 normal tissue specimens showed that Id2, a gene that controls the cell cycle, was significantly up-regulated in SCC. Enforced expression of Id2 in vitro stimulated the proliferation of SCC cells and up-regulated the transcription of nuclear factor kappa B (NF-κB) and cyclin D1. Enhancement of the NF-κB activity with p65 significantly increased the cell proliferation and the transcription of cyclin D1, whereas inhibition of the NF-κB activity with I kappa B alpha mutant (IκBα M) and pyrroline dithiocarbamate (PDTC) abrogated cell proliferation and transcription of cyclin D1. Furthermore, a mutated NF-κB binding site in the cyclin D1 promoter fully abrogated the Id2-induced transcription of cyclin D1. Taken together, these data indicate that Id2 induces SCC tumor growth and proliferation through the NF-κB/cyclin D1 pathway.
基金financially supported by the Natural Science Foundation of China (Nos.U1610101 and 21776288)the Green Process Manufacturing Innovation Research Institute, Chinese Academy of Sciences (No.IAGM-2019-A09)the funding support from Vinnova (Dn: 2018-05293)。
文摘A type of calcium coke was developed for use in the oxy-thermal process of calcium carbide production.The calcium coke was prepared by the co-pyrolysis of coking coal and calcium carbide slag, which is a solid waste generated from the chlor-alkali industry.The characteristics of the calcium cokes under different conditions were analyzed experimentally and theoretically.The results show that the thermal strength of calcium coke increased with the increase in the coking coal proportion, and the waterproof property of calcium coke also increased with increased carbonation time.The calcium coke can increase the contact area of calcium and carbon in the calcium carbide production process.Furthermore, the pore structure of the calcium coke can enhance the diffusion of gas inside the furnace, thus improving the efficiency of the oxy-thermal technology.
基金National Natural Science Foundation of China,No.81373084 and No.81273065the Norman Bethune Program of Jilin Universit,No.2013025the Youth Fund of the First Hospital of Jilin University,No.JDYY42013014
文摘AIM: To investigate the role of single nucleotide polymorphisms(SNPs) in CD24 gene in susceptibility and overall survival of gastric cancer(GC).METHODS: We genotyped 3 tagging SNPs of CD24-P-534 in the promoter region, P170 in the coding region of exon 2 and P1527 in the 3′ untranslated region- using polymerase chain reaction-restriction fragment length polymorphism in specimens from 679 histologically-confirmed GC cases, 111 gastric atrophy(GA) cases and 976 tumor-free controls. Serumimmunoglobulin G antibodies to Helicobacter pylori(H. pylori) of all subjects were detected by enzyme-linked immunosorbent assay. CD24 expression was evaluated by immunohistochemistry in 131 GC specimens. Correlations between SNPs and risk of GC or GA were shown by P values and odd ratios(ORs) with 95% confidence intervals(95%CI) compared with the most common genotype of each SNP using the unconditional logistic regression model after adjusting for age, sex and H. pylori infection. Survival within each SNP group was plotted by Kaplan-Meier method and compared by log-rank test(recessive model). Hazard ratios with 95%CIs were computed by Cox regression model after adjusting for age, sex, histological type, tumor differentiation, clinical stage and post-operational chemotherapy.RESULTS: All of the three loci were in Hardy-Weinberg equilibrium in the control group. Median followup time for the 600 GC patients included in the survival analysis was 36.2 mo(range, 2.1-66.7 mo; 95%CI: 34.3-36.5 mo). Patients with the P-534 A/A genotype had significantly shorter survival(HR = 1.38, 95%CI: 1.01-1.88, P = 0.042) than did the C/C or C/A genotype carriers after adjusting for age, sex, histological type, tumor differentiation, clinical stage and post-operational chemotherapy. This trend was more evident in patients who lived longer than 2.5 years(HR = 7.55, 95%CI: 2.16-26.32, P = 0.001). The P170 T/T genotype was associated with a shorter lifespan than the non-T/T genotypes, but not significantly so. None of the three genetic variants was found to be associated with risk of GC(including tumor stage, grade and distant metastasis) or with risk of gastric atrophy. Furthermore, no difference of CD24 expression was found among the genotypes.CONCLUSION: The P-534 site in CD24 gene affects the overall survival of gastric cancer and may serve as a prognostic marker for gastric cancer.
基金supported by the National Natural Science Foundation of China (Grant no. 61705090)
文摘Conjugated polymers are commonly used as effective hole transport materials(HTMs) for preparation of high-performance perovskite solar cells. However, the hydrophobic nature of these materials renders it difficult to deposit photovoltaic perovskite layers on top via solution processing. In this article, we report a generic surface modification strategy that enables the deposition of uniform and dense perovskite films on top of non-wetting interfaces. In contrast to the previous proposed chemical modifications which might alter the optoelectronic properties of the interfacial layers, we realized a nondestructive surface modification enabled by introducing a layer of insulating mesoporous aluminum oxide(Al2O3). The surface energies of the typical non-wetting hole-transport layers(PTAA, P3 HT, and Poly-TPD) were significantly reduced by the Al2O3 modification. Benefiting from the intact optoelectronic properties of the HTMs, perovskite solar cells deposited on these interface materials show full open-circuit voltages( V OC) with high fill factors(FF) up to 80%. Our method provides an effective avenue for exploiting the full potential of the existing as well as newly developed non-wetting interface materials for the fabrication of high-performance inverted perovskite solar cells.
基金funding support of the State Key Research Development Program of China (Nos. 2016YFC0600708 and 2016YFC0801402)
文摘This paper focuses on anisotropy of coal permeability and its stress sensitivity.Coal blocks were taken from Xinjing Coal Mine in Yangquan Coal District.Coal cores were then drilled along the strike,dip,and vertical directions.Coal permeabilities were measured with respect to stress by using a self-developed coal permeability measurement system.The used samples exhibited significant permeability anisotropy.The permeability along the strike direction was greatest among the three directions,the permeability along the vertical direction was the smallest,and the permeability along the dip direction was between the other two directions.The sensitivity of coal permeability to stress was transversely isotropic.The stress sensitivity coefficient was greater along the horizontal directions than along the vertical directions.Coal permeability exhibited anisotropic stress sensitivity due to anisotropy in Young’s modulus and porosity.The results obtained in this study are useful for optimizing the arrangement of pre-drainage boreholes.
基金the National Nat-ural Science Foundation of China(Nos.52074029,51804026)the USTB-NTUT Joint Research Program(No.06310063)Chuan Wang would like to acknowledge the funding support from Vinnova(dnr:2017-01327).
文摘Combustion kinetics of the hydrochar was investigated using a multi-Gaussian-distributed activation energy model(DAEM)to ex-pand the knowledge on the combustion mechanisms.The results demonstrated that the kinetic parameters calculated by the multi-Gaussian-DAEM accurately represented the experimental conversion rate curves.Overall,the feedstock combustion could be divided into four stages:the decomposition of hemicellulose,cellulose,lignin,and char combustion.The hydrochar combustion could in turn be divided into three stages:the combustion of cellulose,lignin,and char.The mean activation energy ranges obtained for the cellulose,lignin,and char were 273.7-292.8,315.1-334.5,and 354.4-370 kJ/mol,respectively,with the standard deviations of 2.1-23.1,9.5-27.4,and 12.1-22.9 kJ/mol,re-spectively.The cellulose and lignin contents first increased and then decreased with increasing hydrothermal carbonization(HTC)temperature,while the mass fraction of char gradually increased.
基金Supported by Science and Technology Program of Sichuan,No.2019YFS0239.
文摘Kawasaki disease(KD)is an acute systemic vasculitis characterized by unknown etiology.CASE SUMMARY A 4.5-year-old boy developed an acute abdomen during the onset of incomplete KD.He still had persistent abdominal pain after undergoing exploratory laparotomy and appendectomy.Ultrasound examination at early onset revealed a giant coronary artery aneurysm.The patient developed a myocardial infarction and heart failure accompanied by respiratory and cardiac arrest.He underwent coronary artery revascularization and coronary artery bypass graft using an autologous internal mammary artery.After the operation,the cardiac output increased,and the symptoms of heart failure resolved.Follow-up evaluation at 1 mo after operation showed that the patient's cardiac function had restored to New York Heart Association standard Grade I heart failure,and normal growth was obtained.CONCLUSION Coronary artery revascularization and coronary artery bypass graft is an effective method for treating myocardial ischemia in children with KD complicated with giant coronary artery aneurysm.Nevertheless,some issues still need specific attention.
基金partially funded by a Washington University Collaboration Initiation Grant (CIG)a Michigan State University Foundation Strategic Partnership Grant (16SPG-Full-3236)
文摘The recent development on wearable and stretchable electronics calls for skin conformable power sources that are beyond current battery technologies.Among the many novel energy devices being explored,triboelectric nanogenerator(TENG)made from intrinsically stretchable materials has a great potential to meet the above requirement as being both soft and efficient.In this paper,we present a lithography-free and low-cost TENG device comprising a porous-structured PDMS layer and a stretchable PEDOT:PSS electrode.The porous PDMS structure is formed by using self-assembled polystyrene beads as the sacrificial template and it is highly ordered with great uniformity and high structural stability under compression force.Moreover,the porous PDMS TENG exhibits improved output voltage and current of 1.65 V and 0.54 nA compared to its counterpart with non-porous PDMS with 0.66 V and 0.34 nA.The effect of different loading force and frequency on the output response of the TENG device has also been studied.This work could shed light on diverse structural modification methods for improving the performance of PDMS-based TENG and the development of intrinsically stretchable TENG for wearable device applications.
基金supported by State Grid Science and Technology Projects(SGTYHT/17-JS-199)National Natural Science Foundation of China(51577163).
文摘The fault current limiter(FCL)is an effective measure for improving system stability and suppressing short-circuit fault current.Because of space and economic costs,the optimum placement of FCLs is vital in industrial applications.In this study,two objectives with the same dimensional measurement unit,namely,the total capital investment cost of FCLs and circuit breaker loss related to short-circuit currents,are considered.The circuit breaker loss model is developed based on the attenuation rule of the circuit breaker service life.The circuit breaker loss is used to quantify the current-limiting effect to avoid the problem of weight selection in a multi-objective problem.The IEEE 10-generator 39-bus system in New England is used to evaluate the performance of the proposed genetic algorithm(GA)method.Comparative and sensitivity analyses are performed.The results of the optimized plan are validated through simulations,indicating the significant potential of the GA for such optimization.
文摘Flexible and wearable sensors that can acquire signals of pressure,temperature,optical input,chemical environment as well as human body physiological and biological parameters,are of critical importance for robotics and health,in which these sensors are hence in urgent demands.On the fundamental side,there are still substantial challenges on how to design and fabricate materials with biocompatibility,robustness and excellent mechanical flexibility,as well as to achieve sensor devices with high performance,low power consumption and good system integration capability.Meanwhile in practical applications,there are also obstacles on the integration of various kinds of sensors with flexible substrates,signal processing and power supply units.With the fast development of Internet of Things(IoT),smart sensors will as well be interconnected to form sensor networks,providing big data for our future intelligent living.All these would deliver a profound socioeconomic impact to our society.