The extraction of potassium from a tablet mixture of K-feldspar ore and CaSO_4by roasting was studied with a focus on the effects of the decomposition behavior of CaSO_4on the potassium extraction process.The roasted ...The extraction of potassium from a tablet mixture of K-feldspar ore and CaSO_4by roasting was studied with a focus on the effects of the decomposition behavior of CaSO_4on the potassium extraction process.The roasted slags were characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM),energy-dispersive X-ray spectroscopy,and thermogravimetric(TG)analysis.The XRD analysis revealed that hydrosoluble mischcrystal K_2Ca_2(SO_4)_3was obtained by ion exchange of Ca^(2+)in CaSO_4and K^+in KAlSi_3O_8.Meanwhile,the intermediate product,SiO_2,separated from KAl Si_3O_8and reacted with CaSO_4to decompose CaSO_4.The SEM results showed that some blowholes emerged on the surface of the CaSO_4particles when they reacted with SiO_2at 1200°C,which indicates that SO_2and O_2gases were released from CaSO_4.The TG curves displayed that pure CaSO_4could not be decomposed below 1200°C,while the mixture of K-feldspar ore and CaSO_4began to lose weight at 1000°C.The extraction rate of potassium and decomposition rate of CaSO_4were 62%and 44%,respectively,at a mass ratio of CaSO_4to K-feldspar ore of 3:1,temperature of 1200°C,tablet-forming pressure of6 MPa,and roasting time of 2 h.The decomposition of CaSO_4reduced the potassium extraction rate;therefore,the required amount of CaSO_4was more than the theoretical amount.However,excess CaSO_4was also undesirable for the potassium extraction reaction because a massive amount of SO_2and O_2gas were derived from the decomposition of CaSO_4,which provided poor contact between the reactants.The SO_2released from CaSO_4decomposition can be effectively recycled.展开更多
Objective Apatinib is a novel inhibitor of vascular endothelial growth factor receptor-2.The goal of this study was to evaluate overall survival(OS)after a combination of transarterial chemoembolization(TACE)and apati...Objective Apatinib is a novel inhibitor of vascular endothelial growth factor receptor-2.The goal of this study was to evaluate overall survival(OS)after a combination of transarterial chemoembolization(TACE)and apatinib in patients with advanced hepatocellular carcinoma(HCC)and to identify the factors affecting patient survival.Methods Fifty-one patients with advanced HCC who received TACE in combination with apatinib in our hospital from June 2015 to May 2017 were enrolled.The OS and progression-free survival(PFS)were calculated using the Kaplan-Meier method.The log-rank test and Cox regression model were used to determine the factors affecting OS.Results The median OS and PFS of the patients were 15 months and 10 months,respectively.The 1-,2-,and 3-year survival rates were 64.7%,23.5%,and 1.8%,respectively.Univariate survival analysis showed that patients with Child-Pugh A(P=0.006),reduction rate of proper hepatic artery(P=0.016),hand-foot syndrome(P=0.005),secondary hypertension(P=0.050),and without ascites(P=0.010)had a better OS.Multivariate analysis showed that hand-foot syndrome(P=0.014),secondary hypertension(P=0.017),and reduction rate of proper hepatic artery(P=0.025)were independent predictors of better OS.Conclusion TACE combined with apatinib is a promising treatment for advanced HCC.Hand-foot syndrome,secondary hypertension,and the reduction rate of proper hepatic artery were associated with a better OS.展开更多
Low-speed rotation of disc in an internal circulation of a novel de-emulsification with rotation-dise horizental contactor(RHC-D) realized de-emulsification for O/W emulsions due to repeated coalescence in oil-wet nar...Low-speed rotation of disc in an internal circulation of a novel de-emulsification with rotation-dise horizental contactor(RHC-D) realized de-emulsification for O/W emulsions due to repeated coalescence in oil-wet narrow channels at a low rotation speed. For three emulsions included ethanol/water/2-ethyl-1-hexanol, ethanol/water/2-ethyl-1-hexanol/SDS(Sodium Dodecyl Sulfonate) and 2-ethyl-1-hexanol/water/SDS emulsion, deemulsification ratios of oil phase could reach 1, 1 and 0.67 respectively at 170 r·min-1, and de-emulsification ratios increased obviously after agitating 10 min. De-emulsification experiment in the seam indicated that oil droplet sizes in O/W emulsion became larger after de-emulsification. The main de-emulsification mechanism in RHCD was the coalescence of oil droplets in oil-wet narrow channels. With increase of the rotation speed, oil droplets dispersed better in the aqueous phase. However, de-emulsification effect enhanced due to the increase of the coalescence rate at a bit higher rotation speed. In addition, internal circulation made those O/W emulsions to be broken repeatedly, consequently de-emulsification ratio increased. Repeated de-emulsification through internal circulation might make continuous extraction of ethanol come true at a low rotation speed.展开更多
Due to the complexity of the valve side winding voltage of the converter transformer,the insulation characteristics of the oil-impregnated pressboard(OIP)of the converter transformer are different from those of the tr...Due to the complexity of the valve side winding voltage of the converter transformer,the insulation characteristics of the oil-impregnated pressboard(OIP)of the converter transformer are different from those of the traditional AC transformer.The study on effect of temperature on the creeping discharge characteristics of OIP under combined AC-DC voltage is seriously inadequate.Therefore,this paper investigates the characteristics of OIP creepage discharge under combined AC-DC voltage and discusses the influence of temperature on creepage discharge characteristics under different temperatures from 70℃to 110℃.The experimental results show that the partial discharge inception voltage and flashover voltage decrease with increasing temperature.The times of low amplitude discharge(LAD)decrease and amplitude of LAD increases.Simultaneously,the times of high amplitude discharge(HAD)gradually in crease at each stage of creepage discharge with higher temperature.The analysis indicates that the charge carriers easily accumulate and quickly migrate directional movement along the electric field ahead of discharging.The residual charge carriers are more easily dissipated after discharging.The'hump'region of LAD moves to the direction of higher discharge magnitude.The interval time between two continuous discharges is shortened obviously.The concentration of HAD accelerates the development of OIP insulation creepage discharge.The temperature had an accelerating effect on the development of discharge in the OIP under applying voltage.展开更多
The significant decrease of acid sites caused by alkali metal poisoning is the major factor in the deactivation of commercial V_(2)O_(5)-WO_(3)/TiO_(2)NH_(3)-SCR catalysts.In this work,the solid superacid SO_(4)^(2-)-...The significant decrease of acid sites caused by alkali metal poisoning is the major factor in the deactivation of commercial V_(2)O_(5)-WO_(3)/TiO_(2)NH_(3)-SCR catalysts.In this work,the solid superacid SO_(4)^(2-)-TiO_(2) modified by sulfate radicals,was selected as the catalyst support,which showed superior potassium resistance.The physicochemical properties and K-poisoning resistance of the V_(2)O_(5)-WO_(3)/SO_(4)^(2-)-TiO_(2)(VWSTi) catalyst were carried out by XRD,BET,H2-TPR,NH3-TPD,XPS,in situ DRIFTS and TG.The results pointed out that the introduction of SO_(4)^(2-)significantly increased the NH3-SCR catalytic activity at high temperatures,with an exceptionally high NO_(x) conversion over 90% between 275℃ and 500℃.When 0.5%(mass) K_(2)O was doped on the catalysts,the catalytic performance of the traditional V_(2)O_(5)-WO_(3)/TiO_(2)(VWTi) catalyst decreased significantly,while the VWSTi catalyst could still maintain a NOxconversion over 90%in the range of 300–500℃.The characterizations suggested that the support of SO_(4)^(2-)-TiO_(2) greatly increased the number of acidic sites,thereby enhancing the adsorption capacity of the reactant NH_(3).The results above demonstrated a potential approach to achieve superior potassium resistance for NH3-SCR catalysts using solid superacid.展开更多
Burning coal briquettes or biomass pellets in household decoupling stoves is of significance to the reduction of residential pollutant emissions such as NO and CO. In order to make full use of the superiority of decou...Burning coal briquettes or biomass pellets in household decoupling stoves is of significance to the reduction of residential pollutant emissions such as NO and CO. In order to make full use of the superiority of decoupling combustion technology, the household stoves should be specially designed and optimized to adapt to fuel types and combustion characteristics. Using numerical simulation and experimental validation, this study quantitatively clarified that the reducibility of devolatilization char plays an important role in the suppression of NO emission in the decoupling combustion of coal, while the reducibility of pyrolysis gases has a dominant effect on the reduction of NO in the decoupling combustion of biomass. An optimal parameter combination of throat height and grate angle was obtained for the simultaneous suppression of NO and CO emissions in the household decoupling stove burning coal briquettes. Two types of decoupling stoves were developed to enable the clean combustion of biomass pellets. The A-type biomass stove with a multi-pass smoke tunnel shows a better comprehensive NO and CO reduction effectiveness than the B-type biomass stove consisting of a two-stage grate structure and an S-shaped pyrolysis chamber. The optimal structural parameters provided references for the design and manufacture of commercial decoupling coal and biomass stoves.展开更多
Rotating packed bed(RPB) is one of the most effective gas–liquid mass transfer enhancement reactors, its effective specific mass transfer area(ae) is critical to understand the mass transfer process. By using the NaO...Rotating packed bed(RPB) is one of the most effective gas–liquid mass transfer enhancement reactors, its effective specific mass transfer area(ae) is critical to understand the mass transfer process. By using the NaOH–CO_(2) chemical absorption method, the aevalues of three RPB reactors with different rotor sizes were measured under different operation conditions. The results showed that the high gravity factor and liquid flow rate were major affecting factors, while the gas flow rate exhibited minor influence.The radius of packing is the dominant equipment factor to affect aevalue. The results indicated that the contact area depends on the dispersion of the liquid phase, thus the centrifugal force of rotating packed bed greatly influenced the aevalue. Moreover, the measured ae/ap(effective specific mass transfer area/specific surface area of packing) values were fitted with dimensionless correlation formulas. The unified correlation formula with dimensionless bed size parameter can well predict the experimental data and the prediction errors were within 15%.展开更多
The long and intricate domestication history of the tomato(Solanum lycopersicum)includes selection sweeps that have not been fully explored,and these sweeps show significant evolutionary trajectories of domestication ...The long and intricate domestication history of the tomato(Solanum lycopersicum)includes selection sweeps that have not been fully explored,and these sweeps show significant evolutionary trajectories of domestication traits.Using three distinct selection strategies,we represented comprehensive selected sweeps from 53 Solanum pimpinellifolium(PIM)and 166 S.lycopersicum(BIG)accessions,which are defined as pseudo-domestication in this study.We identified 390 potential selection sweeps,some of which had a significant impact on fruit-related traits and were crucial to the pseudo-domestication process.During tomato pseudo-domestication,we discovered a minor–effect allele of the SlLEA gene related to fruit weight(FW),as well as the major haplotypes of fw2.2/cell number regulator(CNR),fw3.2/SlKLUH,and fw11.3/cell size regulator(CSR)in cultivars.Furthermore,18 loci were found to be significantly associated with FW and six fruit-related agronomic traits in genome-wide association studies.By examining population differentiation,we identified the causative variation underlying the divergence of fruit flavonoids across the large-fruited tomatoes and validated BRI1-EMS-SUPPRESSOR 1.2(SlBES1.2),a gene that may affect flavonoid content by modulating the MYB12 expression profile.Our results provide new research routes for the genetic basis of fruit traits and excellent genomic resources for tomato genomics-assisted breeding.展开更多
Turbulence is a thermodynamic system composed of a lot of vorticons rather than disturbance to random moving particles. The transport coefficients derived from the definition on turbulence show that the anomalous tran...Turbulence is a thermodynamic system composed of a lot of vorticons rather than disturbance to random moving particles. The transport coefficients derived from the definition on turbulence show that the anomalous transport is a natural result of present turbulence in Tokamak plasma and provides an important theoretical reference for the design and operation of Tokamak.展开更多
AIM:To explore the morbidity and risk factors of postoperative pancreatic fistula(POPF)following pancreaticoduodenectomy.METHODS:The data from 196 consecutive patients who underwent pancreaticoduodenectomy,performed b...AIM:To explore the morbidity and risk factors of postoperative pancreatic fistula(POPF)following pancreaticoduodenectomy.METHODS:The data from 196 consecutive patients who underwent pancreaticoduodenectomy,performed by different surgeons,in the General Hospital of the People’s Liberation Army between January 1st,2013and December 31st,2013 were retrospectively collected for analysis.The diagnoses of POPF and clinically relevant(CR)-POPF following pancreaticoduodenectomy were judged strictly by the International Study Group on Pancreatic Fistula Definition.Univariate analysis was performed to analyze the following factors:patient age,sex,body mass index(BMI),hypertension,diabetes mellitus,serum CA19-9 level,history of jaundice,serum albumin level,blood loss volume,pancreatic duct diameter,pylorus preserving pancreaticoduodenectomy,pancreatic drainage and pancreaticojejunostomy.Multivariate logistic regression analysis was used to determine the main independent risk factors for POPF.RESULTS:POPF occurred in 126(64.3%)of the patients,and the incidence of CR-POPF was 32.7%(64/196).Patient characteristics of age,sex,BMI,hypertension,diabetes mellitus,serum CA19-9 level,history of jaundice,serum albumin level,blood loss volume,pylorus preserving pancreaticoduodenectomy and pancreaticojejunostomy showed no statistical difference related to the morbidity of POPF or CR-POPF.Pancreatic duct diameter was found to be significantly correlated with POPF rates by univariate analysis and multivariate regression analysis,with a pancreatic duct diameter≤3 mm being an independent risk factor for POPF(OR=0.291;P=0.000)and CR-POPF(OR=0.399;P=0.004).The CR-POPF rate was higher in patients without external pancreatic stenting,which was found to be an independent risk factor for CR-POPF(OR=0.394;P=0.012).Among the entire patient series,there were three postoperative deaths,giving a total mortality rate of 1.5%(3/196),and the mortality associated with pancreatic fistula was 2.4%(3/126).CONCLUSION:A pancreatic duct diameter≤3 mm is an independent risk factor for POPF.External stent drainage of pancreatic secretion may reduce CR-POPF mortality and POPF severity.展开更多
Large quantities of CO_2 and blast furnace slag are discharged in the iron and steel industry. Mineral carbonation of blast furnace slag can offer substantial CO_2 emission reduction and comprehensive utilization of t...Large quantities of CO_2 and blast furnace slag are discharged in the iron and steel industry. Mineral carbonation of blast furnace slag can offer substantial CO_2 emission reduction and comprehensive utilization of the solid waste.This paper describes a novel route for indirect mineral carbonation of titanium-bearing blast furnace(TBBF) slag,in which the TBBF slag is roasted with recyclable(NH_4)_2SO_4(AS) at low temperatures and converted into the sulphates of various valuable metals, including calcium, magnesium, aluminium and titanium. High value added Ti-and Al-rich products can be obtained through stepwise precipitation of the leaching solution from the roasted slag. The NH_3 produced during the roasting is used to capture CO_2 from flue gases. The NH_4HCO_3 and(NH_4)_2CO_3 thus obtained are used to carbonate the CaSO_4-containing leaching residue and MgSO_4-rich leaching solution, respectively. In this study, the process parameters and efficiency for the roasting, carbonation and Ti and Al recovery were investigated in detail. The results showed that the sulfation ratios of calcium,magnesium, titanium and aluminium reached 92.6%, 87% and 84.4%, respectively, after roasting at an AS-to-TBBF slag mass ratio of 2:1 and 350 °C for 2 h. The leaching solution was subjected to hydrolysis at 102 °C for 4 h with a Ti hydrolysis ratio of 95.7% and the purity of TiO_2 in the calcined hydrolysate reached 98 wt%.99.7% of aluminium in the Ti-depleted leaching solution was precipitated by using NH_3. The carbonation products of Ca and Mg were CaCO_3 and(NH_4)_2 Mg(CO_3)_2·4H_2O, respectively. The latter can be decomposed into MgCO_3 at 100–200 °C with simultaneous recovery of the NH_3 for reuse. In this process, approximately 82.1% of Ca and 84.2%of Mg in the TBBF slag were transformed into stable carbonates and the total CO_2 sequestration capacity per ton of TBBF slag reached up to 239.7 kg. The TiO_2 obtained can be used directly as an end product, while the Al-rich precipitate and the two carbonation products can act, respectively, as raw materials for electrolytic aluminium,cement and light magnesium carbonate production for the replacement of natural resources.展开更多
The issues of reducing CO_2 emissions, sustainably utilizing natural mineral resources, and dealing with industrial waste offer challenges for sustainable development in energy and the environment. We propose an effic...The issues of reducing CO_2 emissions, sustainably utilizing natural mineral resources, and dealing with industrial waste offer challenges for sustainable development in energy and the environment. We propose an efficient methodology via the co-reaction of K-feldspar and phosphogypsum for the extraction of soluble potassium salts and recovery of SO_2 with reduced CO_2 emission and energy consumption. The results of characterization and reactivity evaluation indicated that the partial melting of K-feldspar and phosphogypsum in the hightemperature co-reaction significantly facilitated the reduction of phosphogypsum to SO_2 and the exchange of K^+(K-feldspar) with Ca^(2+)(CaSO_4 in phosphogypsum). The reaction parameters were systematically investigated with the highest sulfur recovery ratio of ~ 60% and K extraction ratio of ~ 87.7%. This novel methodology possesses an energy consumption reduction of ~ 28% and CO_2 emission reduction of ~ 55% comparing with the present typical commercial technologies for utilization of K-feldspar and the treatment of phosphogypsum.展开更多
The issues of reducing CO_2 levels in the atmo-sphere, sustainably utilizing natural mineral resources,and dealing with indus trial waste offer challenging opportunities for sustainable development in energy and the e...The issues of reducing CO_2 levels in the atmo-sphere, sustainably utilizing natural mineral resources,and dealing with indus trial waste offer challenging opportunities for sustainable development in energy and the environment. The latest advances in CO_2 mineralization technology involving natural minerals and industrial waste are summarized in this paper, with great emphasis on the advancement of fundamental science, economic evaluation, and engineering applications. We discuss several lead-ing large-scale CO_2 mineralization methodologies from a techn ical and engineering-science perspective. For each technology option, we give an overview of the technical parameters, reaction pathway, reactivity, procedural scheme, and laboratorial and pilot devices. Furthermore, we present a discussion of each technology based on experimental results and the literature. Finally, current gaps in knowledge are identified in the conclusion, and an overview of the challenges and opportunities for future research in this field is provided.展开更多
Large quantities of CO_2 and blast furnace slag are discharged in the iron and steel industry. Mineral carbonation of blast furnace slag can offer substantial CO_2 emission reduction and comprehensive utilisation of t...Large quantities of CO_2 and blast furnace slag are discharged in the iron and steel industry. Mineral carbonation of blast furnace slag can offer substantial CO_2 emission reduction and comprehensive utilisation of the solid waste. In this study, a recyclable extractant,(NH_4)_2SO_4, was used to extract calcium and magnesium from blast furnace slag(main phases of gehlenite and akermanite) by using low-temperature roasting to fix CO_2 through aqueous carbonation. The process parameters and efficiency of the roasting extraction, mineralisation, and Al recovery were investigated in detail. The results showed that the extractions of Ca, Mg, and Al can reach almost 100% at an(NH4)_2SO_4-to-slag mass ratio of 3:1 and at 370°C in 1 h. Adjusting the p H value of the leaching solution of the roasted slag to 5.5 with the NH_3 released during the roasting resulted in 99% Al precipitation, while co-precipitation of Mg was lower than 2%. The Mg-rich leachate after the depletion of Al and the leaching residue(main phases of CaSO_4 and SiO_2) were carbonated using(NH_4)_2CO_3 and NH_4HCO_3 solutions, respectively, under mild conditions. Approximately 99% of Ca and 89% of Mg in the blast furnace slag were converted into CaCO_3 and(NH_4)_2 Mg(CO_3)_2·4 H_2O,respectively. The latter can be selectively decomposed to magnesium carbonate at 100-200 °C to recover the NH_3 for reuse. In the present route, the total CO_2 sequestration capacity per tonne of blast furnace slag reached up to 316 kg, and 313 kg of Al-rich precipitate, 1000 kg of carbonated product containing CaCO_3 and SiO_2, and 304 kg of carbonated product containing calcium carbonate and magnesium carbonate were recovered simultaneously. These products can be used, respectively, as raw materials for the production of electrolytic aluminium, cement, and light magnesium carbonate to replace natural resources.展开更多
In this study,a route for simultaneous mineralization of CO2 and production of titanium dioxide and ammonium alum,and microporous silicon dioxide from titanium-bearing blast furnace slag(TBBF slag)was proposed,which i...In this study,a route for simultaneous mineralization of CO2 and production of titanium dioxide and ammonium alum,and microporous silicon dioxide from titanium-bearing blast furnace slag(TBBF slag)was proposed,which is comprised of(NH4)2 S04 roasting,acid leaching,ammonium alum crystallization,silicic acid flocculation and Ti hydrolysis.The effects of relevant process parameters were systematically investigated.The re sults showed that under the optimal roasting and leaching conditions about 85%of titanium and 84.6%of aluminum could be extracted while only 30%of silicon entered the leachate.84%of Al^3+was crystallized from the leachate in the form of ammonium aluminum sulfate dodecahydrate with a purity up to 99.5 wt%.About 85%of the soluble silicic acid was flocculated with the aid of secondary alcohol polyoxyethylene ether 9(AEO-9)to yield a microporous SiO2 material(97.4 wt%)from the crystallized mother liquor.The Al-and Si-depleted solution was then hydrolyzed to generate a titanium dioxide(99.1 wt%)with uniform particle size distribution.It was figured out that approximately 146 kg TiO2 could be produced from 1000 kg of TBBF slag.Therefore,the improved process is a promising method for industrial application.展开更多
Post-combustion CO_2 capture(PCC) process faces significant challenge of high regeneration energy consumption.Biphasic absorbent is a promising alternative candidate which could significantly reduce the regeneration e...Post-combustion CO_2 capture(PCC) process faces significant challenge of high regeneration energy consumption.Biphasic absorbent is a promising alternative candidate which could significantly reduce the regeneration energy consumption because only the CO_2-concentrated phase should be regenerated. In this work, aqueous solutions of triethylenetetramine(TETA) and N,N-diethylethanolamine(DEEA) are found to be efficient biphasic absorbents of CO_2. The effects of the solvent composition, total amine concentration, and temperature on the absorption behavior, as well as the effect of temperature on the desorption behavior of TETA–DEEA–H2 O system were investigated. An aqueous solution of 1 mol·L-1 TETA and 4 mol·L-1 DEEA spontaneously separates into two liquid phases after a certain amount of CO_2 is absorbed and it shows high CO_2 absorption/desorption performance.About 99.4% of the absorbed CO_2 is found in the lower phase, which corresponds to a CO_2 absorption capacity of 3.44 mol·kg-1. The appropriate absorption and desorption temperatures are found to be 30 °C and 90 °C,respectively. The thermal analysis indicates that the heat of absorption of the 1 mol·L-1 TETA and 4 mol·L-1 DEEA solution is-84.38 kJ·(mol CO_2)-1 which is 6.92 kJ·(mol CO_2)-1 less than that of aqueous MEA. The reaction heat, sensible heat, and the vaporization heat of the TETA–DEEA–H2 O system are lower than that of the aqueous MEA, while its CO_2 capacity is higher. Thus the TETA–DEEA–H2 O system is potentially a better absorbent for the post-combustion CO_2 capture process.展开更多
As a major configuration of membrane elements,multi-channel porous inorganic membrane tubes were studied by means of theoretical analysis and simulation.Configuration optimization of a cylindrical 37-channel porous in...As a major configuration of membrane elements,multi-channel porous inorganic membrane tubes were studied by means of theoretical analysis and simulation.Configuration optimization of a cylindrical 37-channel porous inorganic membrane tube was studied by increasing membrane filtration area and increasing permeation efficiency of inner channels.An optimal ratio of the channel diameter to the inter-channel distance was proposed so as to increase the total membrane filtration area of the membrane tube.The three-dimensional computational fluid dynamics(CFD) simulation was conducted to study the cross-flow permeation flow of pure water in the 37-channel ceramic membrane tube.A model combining Navier–Stokes equation with Darcy's law and the porous jump boundary conditions was applied.The relationship between permeation efficiency and channel locations,and the method for increasing the permeation efficiency of inner channels were proposed.Some novel multichannel membrane configurations with more permeate side channels were put forward and evaluated.展开更多
Objective: Infra-pyloric artery(IPA) is an important anatomical landmark in treatment of gastric cancer and is the key vessel for pylorus-preserving gastrectomy and subgroup of infra-pyloric lymph nodes. However, its ...Objective: Infra-pyloric artery(IPA) is an important anatomical landmark in treatment of gastric cancer and is the key vessel for pylorus-preserving gastrectomy and subgroup of infra-pyloric lymph nodes. However, its anatomical variation is not thoroughly understood. Our study aimed to clarify the origination of the IPA.Methods: We did this prospective, multicenter, open-label, observational study at gastric surgery departments of34 hospitals in China. Gastric cancer patients aged 18 years or older and scheduled to undergo elective total or distal gastrectomy were assigned. During the surgery, IPA dissecting and exposing the origination point with photographs or video clips were required. The primary outcome was the origination of the IPA. Analysis of variance, χ~2 tests and Fisher's tests were used to analyze the differences between groups. The study is registered at Clinicaltrials.gov(No. NCT03071237).Results: Between May 8 and July 31, 2017, 429 patients were assigned for the study, and 419(97.7%) patients had the IPA dissected and recorded through photograph or video and were included in the primary outcome analysis. The median age was 62 years old, and 73.7% were male. Among the patients, 78.5% received laparoscopic surgery. Single IPA origination was identified in 398(95.0%) patients, including gastroduodenal artery(GDA) in154(36.8%) patients, anterior superior pancreaticoduodenal artery(ASPDA) in 130(31.0%) patients, and right gastroepiploic artery(RGEA) in 114(27.2%) patients. Fifteen(3.6%) patients were identified with multiple IPA and 6(1.4%) patients were identified as IPA absence. The differences in the distribution of surgical approach(P=0.003) and geographic area(P=0.030) were statistically significant. No difference was shown in sex, age,gastrectomy type, tumor location, and clinical T, N and M stage.Conclusions: Our study found that the IPA originates from GDA, ASPDA and RGEA in similar proportions.Laparoscopic surgery may be more helpful in dissection of the IPA than open surgery.展开更多
基金Supported by the National Key Research and Development Program(2016YFB0600904)Sichuan Province Science and Technology Project(2017GZ0377)Sichuan University Postdoctoral Research and Development Fund(2017SCU12017)
文摘The extraction of potassium from a tablet mixture of K-feldspar ore and CaSO_4by roasting was studied with a focus on the effects of the decomposition behavior of CaSO_4on the potassium extraction process.The roasted slags were characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM),energy-dispersive X-ray spectroscopy,and thermogravimetric(TG)analysis.The XRD analysis revealed that hydrosoluble mischcrystal K_2Ca_2(SO_4)_3was obtained by ion exchange of Ca^(2+)in CaSO_4and K^+in KAlSi_3O_8.Meanwhile,the intermediate product,SiO_2,separated from KAl Si_3O_8and reacted with CaSO_4to decompose CaSO_4.The SEM results showed that some blowholes emerged on the surface of the CaSO_4particles when they reacted with SiO_2at 1200°C,which indicates that SO_2and O_2gases were released from CaSO_4.The TG curves displayed that pure CaSO_4could not be decomposed below 1200°C,while the mixture of K-feldspar ore and CaSO_4began to lose weight at 1000°C.The extraction rate of potassium and decomposition rate of CaSO_4were 62%and 44%,respectively,at a mass ratio of CaSO_4to K-feldspar ore of 3:1,temperature of 1200°C,tablet-forming pressure of6 MPa,and roasting time of 2 h.The decomposition of CaSO_4reduced the potassium extraction rate;therefore,the required amount of CaSO_4was more than the theoretical amount.However,excess CaSO_4was also undesirable for the potassium extraction reaction because a massive amount of SO_2and O_2gas were derived from the decomposition of CaSO_4,which provided poor contact between the reactants.The SO_2released from CaSO_4decomposition can be effectively recycled.
基金supported by the National Natural Science Foundation of China(No.81771950,No.81471765 and No.81601578).
文摘Objective Apatinib is a novel inhibitor of vascular endothelial growth factor receptor-2.The goal of this study was to evaluate overall survival(OS)after a combination of transarterial chemoembolization(TACE)and apatinib in patients with advanced hepatocellular carcinoma(HCC)and to identify the factors affecting patient survival.Methods Fifty-one patients with advanced HCC who received TACE in combination with apatinib in our hospital from June 2015 to May 2017 were enrolled.The OS and progression-free survival(PFS)were calculated using the Kaplan-Meier method.The log-rank test and Cox regression model were used to determine the factors affecting OS.Results The median OS and PFS of the patients were 15 months and 10 months,respectively.The 1-,2-,and 3-year survival rates were 64.7%,23.5%,and 1.8%,respectively.Univariate survival analysis showed that patients with Child-Pugh A(P=0.006),reduction rate of proper hepatic artery(P=0.016),hand-foot syndrome(P=0.005),secondary hypertension(P=0.050),and without ascites(P=0.010)had a better OS.Multivariate analysis showed that hand-foot syndrome(P=0.014),secondary hypertension(P=0.017),and reduction rate of proper hepatic artery(P=0.025)were independent predictors of better OS.Conclusion TACE combined with apatinib is a promising treatment for advanced HCC.Hand-foot syndrome,secondary hypertension,and the reduction rate of proper hepatic artery were associated with a better OS.
文摘Low-speed rotation of disc in an internal circulation of a novel de-emulsification with rotation-dise horizental contactor(RHC-D) realized de-emulsification for O/W emulsions due to repeated coalescence in oil-wet narrow channels at a low rotation speed. For three emulsions included ethanol/water/2-ethyl-1-hexanol, ethanol/water/2-ethyl-1-hexanol/SDS(Sodium Dodecyl Sulfonate) and 2-ethyl-1-hexanol/water/SDS emulsion, deemulsification ratios of oil phase could reach 1, 1 and 0.67 respectively at 170 r·min-1, and de-emulsification ratios increased obviously after agitating 10 min. De-emulsification experiment in the seam indicated that oil droplet sizes in O/W emulsion became larger after de-emulsification. The main de-emulsification mechanism in RHCD was the coalescence of oil droplets in oil-wet narrow channels. With increase of the rotation speed, oil droplets dispersed better in the aqueous phase. However, de-emulsification effect enhanced due to the increase of the coalescence rate at a bit higher rotation speed. In addition, internal circulation made those O/W emulsions to be broken repeatedly, consequently de-emulsification ratio increased. Repeated de-emulsification through internal circulation might make continuous extraction of ethanol come true at a low rotation speed.
基金supported by the Natural Science Foundation of Qinghai Province(No.2016-ZJ-925Q)Chinese National Programs for Fundamental Research(No.2011CB209400)
文摘Due to the complexity of the valve side winding voltage of the converter transformer,the insulation characteristics of the oil-impregnated pressboard(OIP)of the converter transformer are different from those of the traditional AC transformer.The study on effect of temperature on the creeping discharge characteristics of OIP under combined AC-DC voltage is seriously inadequate.Therefore,this paper investigates the characteristics of OIP creepage discharge under combined AC-DC voltage and discusses the influence of temperature on creepage discharge characteristics under different temperatures from 70℃to 110℃.The experimental results show that the partial discharge inception voltage and flashover voltage decrease with increasing temperature.The times of low amplitude discharge(LAD)decrease and amplitude of LAD increases.Simultaneously,the times of high amplitude discharge(HAD)gradually in crease at each stage of creepage discharge with higher temperature.The analysis indicates that the charge carriers easily accumulate and quickly migrate directional movement along the electric field ahead of discharging.The residual charge carriers are more easily dissipated after discharging.The'hump'region of LAD moves to the direction of higher discharge magnitude.The interval time between two continuous discharges is shortened obviously.The concentration of HAD accelerates the development of OIP insulation creepage discharge.The temperature had an accelerating effect on the development of discharge in the OIP under applying voltage.
基金supported by the National Natural Science Foundation of China (22108184)China Postdoctoral Science Foundation (2021TQ0221)+1 种基金the Sichuan Science and Technology Program (2021JDRC0117)Chengdu Science and Technology Program (2021-YF05-00378-SN)。
文摘The significant decrease of acid sites caused by alkali metal poisoning is the major factor in the deactivation of commercial V_(2)O_(5)-WO_(3)/TiO_(2)NH_(3)-SCR catalysts.In this work,the solid superacid SO_(4)^(2-)-TiO_(2) modified by sulfate radicals,was selected as the catalyst support,which showed superior potassium resistance.The physicochemical properties and K-poisoning resistance of the V_(2)O_(5)-WO_(3)/SO_(4)^(2-)-TiO_(2)(VWSTi) catalyst were carried out by XRD,BET,H2-TPR,NH3-TPD,XPS,in situ DRIFTS and TG.The results pointed out that the introduction of SO_(4)^(2-)significantly increased the NH3-SCR catalytic activity at high temperatures,with an exceptionally high NO_(x) conversion over 90% between 275℃ and 500℃.When 0.5%(mass) K_(2)O was doped on the catalysts,the catalytic performance of the traditional V_(2)O_(5)-WO_(3)/TiO_(2)(VWTi) catalyst decreased significantly,while the VWSTi catalyst could still maintain a NOxconversion over 90%in the range of 300–500℃.The characterizations suggested that the support of SO_(4)^(2-)-TiO_(2) greatly increased the number of acidic sites,thereby enhancing the adsorption capacity of the reactant NH_(3).The results above demonstrated a potential approach to achieve superior potassium resistance for NH3-SCR catalysts using solid superacid.
基金financial supports from the “Transformational Technologies for Clean Energy and Demonstration”, Strategic Priority Research Program of Chinese Academy of Sciences (XDA21040400)。
文摘Burning coal briquettes or biomass pellets in household decoupling stoves is of significance to the reduction of residential pollutant emissions such as NO and CO. In order to make full use of the superiority of decoupling combustion technology, the household stoves should be specially designed and optimized to adapt to fuel types and combustion characteristics. Using numerical simulation and experimental validation, this study quantitatively clarified that the reducibility of devolatilization char plays an important role in the suppression of NO emission in the decoupling combustion of coal, while the reducibility of pyrolysis gases has a dominant effect on the reduction of NO in the decoupling combustion of biomass. An optimal parameter combination of throat height and grate angle was obtained for the simultaneous suppression of NO and CO emissions in the household decoupling stove burning coal briquettes. Two types of decoupling stoves were developed to enable the clean combustion of biomass pellets. The A-type biomass stove with a multi-pass smoke tunnel shows a better comprehensive NO and CO reduction effectiveness than the B-type biomass stove consisting of a two-stage grate structure and an S-shaped pyrolysis chamber. The optimal structural parameters provided references for the design and manufacture of commercial decoupling coal and biomass stoves.
基金the support from the National Natural Science Foundation of China (22008157,21978178)。
文摘Rotating packed bed(RPB) is one of the most effective gas–liquid mass transfer enhancement reactors, its effective specific mass transfer area(ae) is critical to understand the mass transfer process. By using the NaOH–CO_(2) chemical absorption method, the aevalues of three RPB reactors with different rotor sizes were measured under different operation conditions. The results showed that the high gravity factor and liquid flow rate were major affecting factors, while the gas flow rate exhibited minor influence.The radius of packing is the dominant equipment factor to affect aevalue. The results indicated that the contact area depends on the dispersion of the liquid phase, thus the centrifugal force of rotating packed bed greatly influenced the aevalue. Moreover, the measured ae/ap(effective specific mass transfer area/specific surface area of packing) values were fitted with dimensionless correlation formulas. The unified correlation formula with dimensionless bed size parameter can well predict the experimental data and the prediction errors were within 15%.
基金This study was supported by the National Natural Science Foundation of China(32072571)the 111 Project(B17043)the Construction of Beijing Science and Technology Innovation and Service Capacity in Top Subjects(CEFF-PXM2019_014207_000032).
文摘The long and intricate domestication history of the tomato(Solanum lycopersicum)includes selection sweeps that have not been fully explored,and these sweeps show significant evolutionary trajectories of domestication traits.Using three distinct selection strategies,we represented comprehensive selected sweeps from 53 Solanum pimpinellifolium(PIM)and 166 S.lycopersicum(BIG)accessions,which are defined as pseudo-domestication in this study.We identified 390 potential selection sweeps,some of which had a significant impact on fruit-related traits and were crucial to the pseudo-domestication process.During tomato pseudo-domestication,we discovered a minor–effect allele of the SlLEA gene related to fruit weight(FW),as well as the major haplotypes of fw2.2/cell number regulator(CNR),fw3.2/SlKLUH,and fw11.3/cell size regulator(CSR)in cultivars.Furthermore,18 loci were found to be significantly associated with FW and six fruit-related agronomic traits in genome-wide association studies.By examining population differentiation,we identified the causative variation underlying the divergence of fruit flavonoids across the large-fruited tomatoes and validated BRI1-EMS-SUPPRESSOR 1.2(SlBES1.2),a gene that may affect flavonoid content by modulating the MYB12 expression profile.Our results provide new research routes for the genetic basis of fruit traits and excellent genomic resources for tomato genomics-assisted breeding.
文摘Turbulence is a thermodynamic system composed of a lot of vorticons rather than disturbance to random moving particles. The transport coefficients derived from the definition on turbulence show that the anomalous transport is a natural result of present turbulence in Tokamak plasma and provides an important theoretical reference for the design and operation of Tokamak.
文摘AIM:To explore the morbidity and risk factors of postoperative pancreatic fistula(POPF)following pancreaticoduodenectomy.METHODS:The data from 196 consecutive patients who underwent pancreaticoduodenectomy,performed by different surgeons,in the General Hospital of the People’s Liberation Army between January 1st,2013and December 31st,2013 were retrospectively collected for analysis.The diagnoses of POPF and clinically relevant(CR)-POPF following pancreaticoduodenectomy were judged strictly by the International Study Group on Pancreatic Fistula Definition.Univariate analysis was performed to analyze the following factors:patient age,sex,body mass index(BMI),hypertension,diabetes mellitus,serum CA19-9 level,history of jaundice,serum albumin level,blood loss volume,pancreatic duct diameter,pylorus preserving pancreaticoduodenectomy,pancreatic drainage and pancreaticojejunostomy.Multivariate logistic regression analysis was used to determine the main independent risk factors for POPF.RESULTS:POPF occurred in 126(64.3%)of the patients,and the incidence of CR-POPF was 32.7%(64/196).Patient characteristics of age,sex,BMI,hypertension,diabetes mellitus,serum CA19-9 level,history of jaundice,serum albumin level,blood loss volume,pylorus preserving pancreaticoduodenectomy and pancreaticojejunostomy showed no statistical difference related to the morbidity of POPF or CR-POPF.Pancreatic duct diameter was found to be significantly correlated with POPF rates by univariate analysis and multivariate regression analysis,with a pancreatic duct diameter≤3 mm being an independent risk factor for POPF(OR=0.291;P=0.000)and CR-POPF(OR=0.399;P=0.004).The CR-POPF rate was higher in patients without external pancreatic stenting,which was found to be an independent risk factor for CR-POPF(OR=0.394;P=0.012).Among the entire patient series,there were three postoperative deaths,giving a total mortality rate of 1.5%(3/196),and the mortality associated with pancreatic fistula was 2.4%(3/126).CONCLUSION:A pancreatic duct diameter≤3 mm is an independent risk factor for POPF.External stent drainage of pancreatic secretion may reduce CR-POPF mortality and POPF severity.
基金Supported by the National Key Projects for Fundamental Research and Development of China(2016YFB0600904)
文摘Large quantities of CO_2 and blast furnace slag are discharged in the iron and steel industry. Mineral carbonation of blast furnace slag can offer substantial CO_2 emission reduction and comprehensive utilization of the solid waste.This paper describes a novel route for indirect mineral carbonation of titanium-bearing blast furnace(TBBF) slag,in which the TBBF slag is roasted with recyclable(NH_4)_2SO_4(AS) at low temperatures and converted into the sulphates of various valuable metals, including calcium, magnesium, aluminium and titanium. High value added Ti-and Al-rich products can be obtained through stepwise precipitation of the leaching solution from the roasted slag. The NH_3 produced during the roasting is used to capture CO_2 from flue gases. The NH_4HCO_3 and(NH_4)_2CO_3 thus obtained are used to carbonate the CaSO_4-containing leaching residue and MgSO_4-rich leaching solution, respectively. In this study, the process parameters and efficiency for the roasting, carbonation and Ti and Al recovery were investigated in detail. The results showed that the sulfation ratios of calcium,magnesium, titanium and aluminium reached 92.6%, 87% and 84.4%, respectively, after roasting at an AS-to-TBBF slag mass ratio of 2:1 and 350 °C for 2 h. The leaching solution was subjected to hydrolysis at 102 °C for 4 h with a Ti hydrolysis ratio of 95.7% and the purity of TiO_2 in the calcined hydrolysate reached 98 wt%.99.7% of aluminium in the Ti-depleted leaching solution was precipitated by using NH_3. The carbonation products of Ca and Mg were CaCO_3 and(NH_4)_2 Mg(CO_3)_2·4H_2O, respectively. The latter can be decomposed into MgCO_3 at 100–200 °C with simultaneous recovery of the NH_3 for reuse. In this process, approximately 82.1% of Ca and 84.2%of Mg in the TBBF slag were transformed into stable carbonates and the total CO_2 sequestration capacity per ton of TBBF slag reached up to 239.7 kg. The TiO_2 obtained can be used directly as an end product, while the Al-rich precipitate and the two carbonation products can act, respectively, as raw materials for electrolytic aluminium,cement and light magnesium carbonate production for the replacement of natural resources.
基金Supported by the National Natural Science Foundation of China(21336004)the State Key Research Plan of the Ministry of Science and Technology(2013BAC12B03)
文摘The issues of reducing CO_2 emissions, sustainably utilizing natural mineral resources, and dealing with industrial waste offer challenges for sustainable development in energy and the environment. We propose an efficient methodology via the co-reaction of K-feldspar and phosphogypsum for the extraction of soluble potassium salts and recovery of SO_2 with reduced CO_2 emission and energy consumption. The results of characterization and reactivity evaluation indicated that the partial melting of K-feldspar and phosphogypsum in the hightemperature co-reaction significantly facilitated the reduction of phosphogypsum to SO_2 and the exchange of K^+(K-feldspar) with Ca^(2+)(CaSO_4 in phosphogypsum). The reaction parameters were systematically investigated with the highest sulfur recovery ratio of ~ 60% and K extraction ratio of ~ 87.7%. This novel methodology possesses an energy consumption reduction of ~ 28% and CO_2 emission reduction of ~ 55% comparing with the present typical commercial technologies for utilization of K-feldspar and the treatment of phosphogypsum.
基金finance support of the Ministry of Science and Technology (State Key Research Plan, 2013BAC12B00)the National Natural Science Foundation of China (21336004 and 51254002)
文摘The issues of reducing CO_2 levels in the atmo-sphere, sustainably utilizing natural mineral resources,and dealing with indus trial waste offer challenging opportunities for sustainable development in energy and the environment. The latest advances in CO_2 mineralization technology involving natural minerals and industrial waste are summarized in this paper, with great emphasis on the advancement of fundamental science, economic evaluation, and engineering applications. We discuss several lead-ing large-scale CO_2 mineralization methodologies from a techn ical and engineering-science perspective. For each technology option, we give an overview of the technical parameters, reaction pathway, reactivity, procedural scheme, and laboratorial and pilot devices. Furthermore, we present a discussion of each technology based on experimental results and the literature. Finally, current gaps in knowledge are identified in the conclusion, and an overview of the challenges and opportunities for future research in this field is provided.
基金financial support of the National Key R&D Program of China(2016YFB0600904)
文摘Large quantities of CO_2 and blast furnace slag are discharged in the iron and steel industry. Mineral carbonation of blast furnace slag can offer substantial CO_2 emission reduction and comprehensive utilisation of the solid waste. In this study, a recyclable extractant,(NH_4)_2SO_4, was used to extract calcium and magnesium from blast furnace slag(main phases of gehlenite and akermanite) by using low-temperature roasting to fix CO_2 through aqueous carbonation. The process parameters and efficiency of the roasting extraction, mineralisation, and Al recovery were investigated in detail. The results showed that the extractions of Ca, Mg, and Al can reach almost 100% at an(NH4)_2SO_4-to-slag mass ratio of 3:1 and at 370°C in 1 h. Adjusting the p H value of the leaching solution of the roasted slag to 5.5 with the NH_3 released during the roasting resulted in 99% Al precipitation, while co-precipitation of Mg was lower than 2%. The Mg-rich leachate after the depletion of Al and the leaching residue(main phases of CaSO_4 and SiO_2) were carbonated using(NH_4)_2CO_3 and NH_4HCO_3 solutions, respectively, under mild conditions. Approximately 99% of Ca and 89% of Mg in the blast furnace slag were converted into CaCO_3 and(NH_4)_2 Mg(CO_3)_2·4 H_2O,respectively. The latter can be selectively decomposed to magnesium carbonate at 100-200 °C to recover the NH_3 for reuse. In the present route, the total CO_2 sequestration capacity per tonne of blast furnace slag reached up to 316 kg, and 313 kg of Al-rich precipitate, 1000 kg of carbonated product containing CaCO_3 and SiO_2, and 304 kg of carbonated product containing calcium carbonate and magnesium carbonate were recovered simultaneously. These products can be used, respectively, as raw materials for the production of electrolytic aluminium, cement, and light magnesium carbonate to replace natural resources.
基金financial support of the National Key Projects for Fundamental Research and Development of China(2016YFB0600904)Sichuan University Postdoctoral Research and Development Fund(2017SCU12017)+1 种基金Project of State Key Laboratory of Vanadium and Titanium Resources Comprehensive Utilization(18H0083)Sichuan Science and Technology Department Project(2019YJ0111)。
文摘In this study,a route for simultaneous mineralization of CO2 and production of titanium dioxide and ammonium alum,and microporous silicon dioxide from titanium-bearing blast furnace slag(TBBF slag)was proposed,which is comprised of(NH4)2 S04 roasting,acid leaching,ammonium alum crystallization,silicic acid flocculation and Ti hydrolysis.The effects of relevant process parameters were systematically investigated.The re sults showed that under the optimal roasting and leaching conditions about 85%of titanium and 84.6%of aluminum could be extracted while only 30%of silicon entered the leachate.84%of Al^3+was crystallized from the leachate in the form of ammonium aluminum sulfate dodecahydrate with a purity up to 99.5 wt%.About 85%of the soluble silicic acid was flocculated with the aid of secondary alcohol polyoxyethylene ether 9(AEO-9)to yield a microporous SiO2 material(97.4 wt%)from the crystallized mother liquor.The Al-and Si-depleted solution was then hydrolyzed to generate a titanium dioxide(99.1 wt%)with uniform particle size distribution.It was figured out that approximately 146 kg TiO2 could be produced from 1000 kg of TBBF slag.Therefore,the improved process is a promising method for industrial application.
基金Supported by the National Natural Science Foundation of China(21606154)
文摘Post-combustion CO_2 capture(PCC) process faces significant challenge of high regeneration energy consumption.Biphasic absorbent is a promising alternative candidate which could significantly reduce the regeneration energy consumption because only the CO_2-concentrated phase should be regenerated. In this work, aqueous solutions of triethylenetetramine(TETA) and N,N-diethylethanolamine(DEEA) are found to be efficient biphasic absorbents of CO_2. The effects of the solvent composition, total amine concentration, and temperature on the absorption behavior, as well as the effect of temperature on the desorption behavior of TETA–DEEA–H2 O system were investigated. An aqueous solution of 1 mol·L-1 TETA and 4 mol·L-1 DEEA spontaneously separates into two liquid phases after a certain amount of CO_2 is absorbed and it shows high CO_2 absorption/desorption performance.About 99.4% of the absorbed CO_2 is found in the lower phase, which corresponds to a CO_2 absorption capacity of 3.44 mol·kg-1. The appropriate absorption and desorption temperatures are found to be 30 °C and 90 °C,respectively. The thermal analysis indicates that the heat of absorption of the 1 mol·L-1 TETA and 4 mol·L-1 DEEA solution is-84.38 kJ·(mol CO_2)-1 which is 6.92 kJ·(mol CO_2)-1 less than that of aqueous MEA. The reaction heat, sensible heat, and the vaporization heat of the TETA–DEEA–H2 O system are lower than that of the aqueous MEA, while its CO_2 capacity is higher. Thus the TETA–DEEA–H2 O system is potentially a better absorbent for the post-combustion CO_2 capture process.
基金Supported by the National Basic Research Program of China(2012CB224806)the National Natural Science Foundation of China(21490584,21476236)the National High Technology Research and Development Program of China(2012AA03A606)
文摘As a major configuration of membrane elements,multi-channel porous inorganic membrane tubes were studied by means of theoretical analysis and simulation.Configuration optimization of a cylindrical 37-channel porous inorganic membrane tube was studied by increasing membrane filtration area and increasing permeation efficiency of inner channels.An optimal ratio of the channel diameter to the inter-channel distance was proposed so as to increase the total membrane filtration area of the membrane tube.The three-dimensional computational fluid dynamics(CFD) simulation was conducted to study the cross-flow permeation flow of pure water in the 37-channel ceramic membrane tube.A model combining Navier–Stokes equation with Darcy's law and the porous jump boundary conditions was applied.The relationship between permeation efficiency and channel locations,and the method for increasing the permeation efficiency of inner channels were proposed.Some novel multichannel membrane configurations with more permeate side channels were put forward and evaluated.
基金funded by the Gastric Cancer Diagnose and Treatment Project(D171100006517004,D17110700650000)of Beijing Municipal Science&Technology Commissionsupported by Beijing Municipal Administration of Hospital Clinical Medicine Development of Special Funding Support(ZYLX201701)
文摘Objective: Infra-pyloric artery(IPA) is an important anatomical landmark in treatment of gastric cancer and is the key vessel for pylorus-preserving gastrectomy and subgroup of infra-pyloric lymph nodes. However, its anatomical variation is not thoroughly understood. Our study aimed to clarify the origination of the IPA.Methods: We did this prospective, multicenter, open-label, observational study at gastric surgery departments of34 hospitals in China. Gastric cancer patients aged 18 years or older and scheduled to undergo elective total or distal gastrectomy were assigned. During the surgery, IPA dissecting and exposing the origination point with photographs or video clips were required. The primary outcome was the origination of the IPA. Analysis of variance, χ~2 tests and Fisher's tests were used to analyze the differences between groups. The study is registered at Clinicaltrials.gov(No. NCT03071237).Results: Between May 8 and July 31, 2017, 429 patients were assigned for the study, and 419(97.7%) patients had the IPA dissected and recorded through photograph or video and were included in the primary outcome analysis. The median age was 62 years old, and 73.7% were male. Among the patients, 78.5% received laparoscopic surgery. Single IPA origination was identified in 398(95.0%) patients, including gastroduodenal artery(GDA) in154(36.8%) patients, anterior superior pancreaticoduodenal artery(ASPDA) in 130(31.0%) patients, and right gastroepiploic artery(RGEA) in 114(27.2%) patients. Fifteen(3.6%) patients were identified with multiple IPA and 6(1.4%) patients were identified as IPA absence. The differences in the distribution of surgical approach(P=0.003) and geographic area(P=0.030) were statistically significant. No difference was shown in sex, age,gastrectomy type, tumor location, and clinical T, N and M stage.Conclusions: Our study found that the IPA originates from GDA, ASPDA and RGEA in similar proportions.Laparoscopic surgery may be more helpful in dissection of the IPA than open surgery.
