A novel core-shell hydrogel bead was fabricated for effective removal of methylene blue dye from aqueous solutions.The core,made of sodium alginate-g-polyacrylamide and attapulgite nanofibers,was cross-linked by Calci...A novel core-shell hydrogel bead was fabricated for effective removal of methylene blue dye from aqueous solutions.The core,made of sodium alginate-g-polyacrylamide and attapulgite nanofibers,was cross-linked by Calcium ions(Ca^(2+)).The shell,composed of a chitosan/activated carbon mixture,was then coated onto the core.Fourier transform infrared spectroscopy confirmed the grafting polymerization of acrylamide onto sodium alginate.Scanning electron microscopy images showed the core-shell structure.The core exhibited a high water uptake ratio,facilitating the diffusion of methylene blue into the core.During the diffusion process,the methylene blue was first adsorbed by the shell and then further adsorbed by the core.Adsorption tests showed that the coreshell structure had a larger adsorption capacity than the core alone.The shell effectively enhanced the adsorption capacity to methylene blue compared to the single core.Methylene blue was adsorbed by activated carbon and chitosan in the shell,and the residual methylene blue diffused into the core and was further adsorbed.展开更多
BACKGROUND The objectives of this study were to assess the safety and efficacy of drug-eluting bead transarterial chemoembolization(DEB-TACE)as neoadjuvant therapy before liver transplantation(LT)for advanced-stage he...BACKGROUND The objectives of this study were to assess the safety and efficacy of drug-eluting bead transarterial chemoembolization(DEB-TACE)as neoadjuvant therapy before liver transplantation(LT)for advanced-stage hepatocellular carcinoma(HCC)and to analyze the prognostic factors.AIM To determine whether DEB-TACE before LT is superior to LT for advanced-stage HCC.METHODS A total of 99 individuals diagnosed with advanced HCC were studied retrospectively.The participants were categorized into the following two groups based on whether they had received DEB-TACE before LT:DEB-TACE group(n=45)and control group(n=54).The participants were further divided into two subgroups based on the presence or absence of segmental portal vein tumor thrombus(PVTT).The DEB-TACE group consisted of two subgroups:Group A(n=31)without PVTT and group B(n=14)with PVTT.The control group also had two subgroups:Group C(n=37)without PVTT and group D(n=17)with PVTT.Data on patient demographics,disease characteristics,therapy response,and adverse events(AEs)were collected.The overall survival(OS)and recurrence-free survival(RFS)rates were assessed using Kaplan-Meier curves.Univariate and multivariate Cox regression analyses were conducted to determine the parameters that were independently related to OS and RFS.RESULTS The DEB-TACE group exhibited an overall response rate of 86.6%.Following therapy,there was a significant decrease in the median alpha-fetoprotein(AFP)level(275.1 ng/mL vs 41.7 ng/mL,P<0.001).The main AE was post-embolization syndrome.The 2-year rates of RFS and OS were significantly higher in the DEB-TACE group than in the control group(68.9%vs 38.9%,P=0.003;86.7%vs 63.0%,P=0.008).Within the subgroups,group A had higher 2-year rates of RFS and OS compared to group C(71.0%vs 45.9%,P=0.038;83.8%vs 62.2%,P=0.047).The 2-year RFS rate of group B was markedly superior to that of group D(64.3%vs 23.5%,P=0.002).Results from multivariate analyses showed that pre-LT DEB-TACE[hazard ratio(HR)=2.73,95%confidence interval(CI):1.44-5.14,P=0.04],overall target tumor diameter≤7 cm(HR=1.98,95%CI:1.05-3.75,P=0.035),and AFP level≤400 ng/mL(HR=2.34;95%CI:1.30-4.19,P=0.009)were significant risk factors for RFS.Additionally,pre-LT DEBTACE(HR=3.15,95%CI:1.43-6.96,P=0.004)was identified as a significant risk factor for OS.CONCLUSION DEB-TACE is a safe and efficient therapy for advanced-stage HCC and also enhances patient survival after LT.展开更多
BACKGROUND The combination of transarterial chemoembolization(TACE),lenvatinib,and programmed cell death 1(PD-1)inhibitor has been widely used in the treatment of advanced hepatocellular carcinoma(HCC)and has achieved...BACKGROUND The combination of transarterial chemoembolization(TACE),lenvatinib,and programmed cell death 1(PD-1)inhibitor has been widely used in the treatment of advanced hepatocellular carcinoma(HCC)and has achieved promising results.However,there are few studies comparing whether drug-eluting beads TACE(DTACE)can bring more survival benefits to patients with large HCC compared to conventional TACE(C-TACE)in this triplet therapy.AIM To compare the efficacy and adverse events(AEs)of triple therapy comprising DTACE,PD-1 inhibitors,and lenvatinib(D-TACE-P-L)and C-TACE,PD-1 inhibitors,and lenvatinib(C-TACE-P-L)in patients with large HCC(maximum diameter≥5 cm),and analyze the prognostic factors.METHODS Following a comprehensive review of our hospital’s medical records,this retrospective study included 104 patients:50 received D-TACE-P-L,and 54 received CTACE-P-L.We employed Kaplan-Meier estimation to assess the median progression-free survival(PFS)between the two groups,utilized Cox multivariate regression analysis to identify prognostic factors,and applied theχ2 test to evaluate AEs.RESULTS The objective response rate(ORR)and median PFS were significantly higher in the D-TACE-P-L group compared to the C-TACE-P-L group(ORR:66.0%vs 44.4%,P=0.027;median PFS:6.8 months vs 5.0 months,P=0.041).Cox regression analysis identified treatment option,portal vein tumor thrombus,and hepatic vein invasion as protective factors for PFS.AEs were comparable between the two CONCLUSION D-TACE-P-L may have significantly better PFS and ORR for large HCC,while exhibiting similar AEs to C-TACE-PL.展开更多
We applied the discrete element method (DEM) of simulation modified by an enlarged particle model to simulate bead motion in a large bead mill. The stainless-steel bead mill has inner diameter of 102 mm and mill len...We applied the discrete element method (DEM) of simulation modified by an enlarged particle model to simulate bead motion in a large bead mill. The stainless-steel bead mill has inner diameter of 102 mm and mill length of 198 mm. The bead diameter and filling ratio were fixed respectively at 0.5 mm and 85%. The agitator rotational speed was changed from 1863 to 3261 rpm. The bead motion was monitored experimentally using a high-speed video camera through a transparent mill body. For the simulation, enlarged particle sizes were set as 3-6 mm in diameter. With the DEM modified by the enlarged particle model, the motion of enlarged particles in a mill was simulated.The velocity data of the simulated enlarged particles were compared with those obtained in the experiment. The simulated velocity of the enlarged particles depends on the virtual frictional coefficient in the DEM model. The optimized value of the virtual frictional coefficient can be determined by considering the accumulated mean value. Results show that the velocity of the enlarged particles simulated increases with an increase in the optimum virtual frictional coefficient, but the simulated velocity agrees well with that determined experimentally by optimizing the virtual frictional coefficient in the simulation. The computing time in the simulation decreases with increased particle size.展开更多
The objective of this work is to construct a nanosuspension drug delivery system of probucol,a BCS II drug,in order to improve its dissolution and oral bioavailability.The wet milling procedure using planetary beads-m...The objective of this work is to construct a nanosuspension drug delivery system of probucol,a BCS II drug,in order to improve its dissolution and oral bioavailability.The wet milling procedure using planetary beads-milling equipment was utilized to grind the raw probucol to ultrafine nanoparticle/nanocrystal aqueous suspension that was further solidified by freeze-drying process.Cellulose derivatives of different substitution groups and molecular weights,including HPMC,HPC,and MC,were evaluated as the primary stabilizer of probucol nanosuspension.Ternary stabilizers system composed of a primary stabilizer(cellulose derivative,i.e.HPC),a nonionic surfactant(Pluronic R F68),and an anionic surfactant(SDS)was employed to obtain probucol nanosuspension of finer particle size and enhanced dissolution in aqueous media.The probucol nanosuspension with good physical stability showed no obvious change of particle size even after storing over 7 d at 4°C or 25°C.The solidified probucol nanosuspension with trehalose as the cryoprotectant showed the highest dissolution rate(>60%at 2 h)compared to other cryoprotectant.The in vivo pharmacokinetic evaluation indicated about 15-folds higher AUC value of the probucol nanosuspension compared to that of coarse probucol suspension after oral administration to rats.The probucol nanosuspension prepared by wet-milling and ternary stabilizers system may find wide applications for improving the dissolution and oral absorption of water-insoluble drugs.展开更多
To investigate influence of welding parameters on weld bead geometry in underwater wet flux cored arc welding (FCAW), orthogonal experiments of underwater wet FCAW were conducted in the hyperbaric chamber at water d...To investigate influence of welding parameters on weld bead geometry in underwater wet flux cored arc welding (FCAW), orthogonal experiments of underwater wet FCAW were conducted in the hyperbaric chamber at water depth from 0.2 m to 60 m and mathematical models were developed by multiple curvilinear regression method from the experimental data. Sensitivity analysis was then performed to predict the bead geometry and evaluate the influence of welding parameters. The results reveal that water depth has a greater influence on bead geometry than other welding parameters when welding at a water depth less than 10 m. At a water depth deeper than 10 m, a change in travel speed affects the bead geometry more strongly than other welding parameters.展开更多
This paper is part of a series addressing the urgent need for effective technologies to reduce energy demand and mitigate climate impact.This study focused on the implementation and development of dynamic insulation t...This paper is part of a series addressing the urgent need for effective technologies to reduce energy demand and mitigate climate impact.This study focused on the implementation and development of dynamic insulation technology for a sustainable and energy-efficient future in the region,especially in Iraq.The study assessed the energy efficiency of dynamic insulation technology by analyzing three wallmodels(static,dynamic,and modified)during thewinter season.This paper expands the analysis to include a hot,dry summer scenario,providing valuable insights into the year-round performance of dynamic walls and enabling sustainable and energy-efficient solutions for Iraq’s climate.The study evaluates the thermal efficiency of the dynamic intake and exhaust facades during the cooling season for the city of Baghdad.The finding indicated that the dynamic intake facade reduces energy consumption by 16.3%for the dynamic wall and 17.2%for the modified dynamic wall.In addition,the dynamic exhaust front reduces energy consumption by 46%during the cooling season,with the maximum permissible exhaust air level.Dynamic insulation is suitable for hot and dry climates,improving energy consumption.展开更多
A problem similar to the famous brachistochrone problem is examined in which, instead of a smooth curve, the path consists of two straight-line sections, one slant and one horizontal. The condition for minimum sliding...A problem similar to the famous brachistochrone problem is examined in which, instead of a smooth curve, the path consists of two straight-line sections, one slant and one horizontal. The condition for minimum sliding time is investigated, producing results that are both counterintuitive and interesting.展开更多
Based on the theory of stability of the liquid metal under the action of surface tension,a physical mod- el is established for the mechanisms of the bead formation deferct' humping', which is generated durin...Based on the theory of stability of the liquid metal under the action of surface tension,a physical mod- el is established for the mechanisms of the bead formation deferct' humping', which is generated during high - speed welding.A boundary function is introduced to correct the model,theoretical results got by the model correspond well with the experimental phenomena. A two - dimensional conducting model is adoopted in the simulation of the temperature field during high - speed welding.Finally, the factors acting upon the stability of liquid metal are analyzed.展开更多
The study examined the adsorption of Pb(II) ions from aqueous solution onto chitosan, chitosan-GLA and chitosan-alginate beads. Several important parameters influencing the adsorption of Pb(II) ions such as initia...The study examined the adsorption of Pb(II) ions from aqueous solution onto chitosan, chitosan-GLA and chitosan-alginate beads. Several important parameters influencing the adsorption of Pb(II) ions such as initial pH, adsorbent dosage and different initial concentration of Pb(II) ions were evaluated. The mechanism involved during the adsorption process was explored based on ion exchange study and using spectroscopic techniques. The adsorption capacities obtained based on non–linear Langmuir isotherm for chitosan, chitosan-GLA and chitosan-alginate beads in single metal system were 34.98, 14.24 and 60.27 mg/g, respectively. However, the adsorption capacity of Pb(II) ions were reduced in the binary metal system due to the competitive adsorption between Pb(II) and Cu(II) ions. Based on the ion exchange study, the release of Ca2+, Mg2+, K+ and Na+ ions played an important role in the adsorption of Pb(II) ions by all three adsorbents but only at lower concentrations of Pb(II) ions. Infrared spectra showed that the binding between Pb(II) ions and the adsorbents involved mostly the nitrogen and oxygen atoms. All three adsorbents showed satisfactory adsorption capacities and can be considered as an efficient adsorbent for the removal of Pb(II) ions from aqueous solutions.展开更多
AIM:To assess the possible effect of two different types of preoperative transcatheter arterial chemoembolization(TACE)on recurrence-free survival after liver transplantation(LT)in patients with hepatocellular carcino...AIM:To assess the possible effect of two different types of preoperative transcatheter arterial chemoembolization(TACE)on recurrence-free survival after liver transplantation(LT)in patients with hepatocellular carcinoma(HCC)and to analyze the effects of TACE on tumor histology.METHODS:We retrospectively analyzed the histological features of 130 HCC nodules in 63 native livers removed at transplantation.Patients who received any other type of treatment such as radiofrequency tumor ablation,percutaneous ethanol ablation or who were not treated at all were excluded.All patients in the present study were within the Milan Criteria at the last imaging findings before transplantation.Doxorubicineluting bead TACE(DEB-TACE)was performed in 22patients(38 nodules),and conventional TACE(c-TACE)in 16(25 nodules).Patients’and tumors’characteristics were retrospectively reviewed.We performed a pernodule analysis of the explanted livers to establish the mean percentage of necrosis of any nodule treated by TACE(conventional or DEB)and a per-patient analysis to establish the percentage of necrosis in the cumulative tumor area,including 21 nodules not reached by TACE.Inflammatory and fibrotic changes in the tissue surrounding the tumor nodule were analyzed and categorized as poor/absent,moderate and enhanced reaction.Uni-and multivariate analysis of risk factors for HCC-recurrence were performed.RESULTS:The number and diameter of the nodules,the time spent on the waiting list and the number of treatments were similar in the two groups.A trend towards higher appropriate response rates(necrosis≥90%)was observed in the DEB-TACE group(44.7%vs32.0%,P=0.2834).The mean percentage of necrosis in the cumulative tumor area was 58.8%±36.6%in the DEB-TACE group and 50.2%±38.1%in the c-TACE group(P=0.4856).Fibrotic and inflammatory reactions surrounding the tumor nodule were markedly more common in the DEB-TACE group(P<0.0001,for both the parameters).The three-year recurrence-free survival was higher in DEB-TACE-treated patients than in conventionally treated patients(87.4%vs 61.5%,P=0.0493).Other factors affecting recurrence-free survival included viable tumor beyond Milan Criteria on histopathological examination,the percentage of necrosis on CTA≤50%and a pre-transplant serum-fetoprotein level greater than 70 ng/mL.On multivariate analysis,the lack of treatment with DEB-TACE,high levels of-fetoprotein and viable tumor beyond Milan Criteria at histology examination were identified as independent predictors of tumor recurrence.CONCLUSION:DEB-TACE can effectively promote tumor necrosis and improves recurrence-free survival after LT in HCC.展开更多
The phosphate-embedded calcium alginate beads were successfully synthesized based on sodium alginate, calcium dihydrogen phosphate and sodium hydrogen carbonate. Scanning electron microscopy, Fourier transformed infra...The phosphate-embedded calcium alginate beads were successfully synthesized based on sodium alginate, calcium dihydrogen phosphate and sodium hydrogen carbonate. Scanning electron microscopy, Fourier transformed infrared (FTIR) spectroscopy and X-ray diffraction (XRD) were conducted to characterize the morphology and structure of the phosphate-embedded calcium alginate beads. The effects of pH and the initial concentration of the metal ions on Pb(II) and Cd(II) sorption by the beads were investigated. The optimal pH values for Pb(II) and Cd(II) sorption are 4.0 and 5.5, respectively. The optimal initial concentrations of Pb(II) and Cd(II) are 200 mg/L and 25 mg/L, correspondingly, and the removal efficiencies are 94.2% and 80%,respectively. The sorption mechanism is that the heavy metal ions accessed the beads firstly due to the large surface area, combinedwith OH?, and then precipitated with phosphate radical, which was proven by FTIR and XRD. The sorption of Pb(II) and Cd(II) isfitted to Langmuir isotherm model with R2 values of 0.9957 and 0.988, respectively. The sorption capacities of Pb(II) and Cd(II) are263.16 mg/g and 82.64 mg/g, respectively. The results indicate that the phosphate-embedded calcium alginate beads could be appliedto treating Pb(II)/Cd(II)-containing wastewater and it could be implied that the synthesized beads also could be used as a kind of soil ameliorant for remediation of the heavy metal contaminated paddy soil.展开更多
文摘A novel core-shell hydrogel bead was fabricated for effective removal of methylene blue dye from aqueous solutions.The core,made of sodium alginate-g-polyacrylamide and attapulgite nanofibers,was cross-linked by Calcium ions(Ca^(2+)).The shell,composed of a chitosan/activated carbon mixture,was then coated onto the core.Fourier transform infrared spectroscopy confirmed the grafting polymerization of acrylamide onto sodium alginate.Scanning electron microscopy images showed the core-shell structure.The core exhibited a high water uptake ratio,facilitating the diffusion of methylene blue into the core.During the diffusion process,the methylene blue was first adsorbed by the shell and then further adsorbed by the core.Adsorption tests showed that the coreshell structure had a larger adsorption capacity than the core alone.The shell effectively enhanced the adsorption capacity to methylene blue compared to the single core.Methylene blue was adsorbed by activated carbon and chitosan in the shell,and the residual methylene blue diffused into the core and was further adsorbed.
基金Supported by Project of Medical and Health Technology Program in Zhejiang Province,No.2020KY787.
文摘BACKGROUND The objectives of this study were to assess the safety and efficacy of drug-eluting bead transarterial chemoembolization(DEB-TACE)as neoadjuvant therapy before liver transplantation(LT)for advanced-stage hepatocellular carcinoma(HCC)and to analyze the prognostic factors.AIM To determine whether DEB-TACE before LT is superior to LT for advanced-stage HCC.METHODS A total of 99 individuals diagnosed with advanced HCC were studied retrospectively.The participants were categorized into the following two groups based on whether they had received DEB-TACE before LT:DEB-TACE group(n=45)and control group(n=54).The participants were further divided into two subgroups based on the presence or absence of segmental portal vein tumor thrombus(PVTT).The DEB-TACE group consisted of two subgroups:Group A(n=31)without PVTT and group B(n=14)with PVTT.The control group also had two subgroups:Group C(n=37)without PVTT and group D(n=17)with PVTT.Data on patient demographics,disease characteristics,therapy response,and adverse events(AEs)were collected.The overall survival(OS)and recurrence-free survival(RFS)rates were assessed using Kaplan-Meier curves.Univariate and multivariate Cox regression analyses were conducted to determine the parameters that were independently related to OS and RFS.RESULTS The DEB-TACE group exhibited an overall response rate of 86.6%.Following therapy,there was a significant decrease in the median alpha-fetoprotein(AFP)level(275.1 ng/mL vs 41.7 ng/mL,P<0.001).The main AE was post-embolization syndrome.The 2-year rates of RFS and OS were significantly higher in the DEB-TACE group than in the control group(68.9%vs 38.9%,P=0.003;86.7%vs 63.0%,P=0.008).Within the subgroups,group A had higher 2-year rates of RFS and OS compared to group C(71.0%vs 45.9%,P=0.038;83.8%vs 62.2%,P=0.047).The 2-year RFS rate of group B was markedly superior to that of group D(64.3%vs 23.5%,P=0.002).Results from multivariate analyses showed that pre-LT DEB-TACE[hazard ratio(HR)=2.73,95%confidence interval(CI):1.44-5.14,P=0.04],overall target tumor diameter≤7 cm(HR=1.98,95%CI:1.05-3.75,P=0.035),and AFP level≤400 ng/mL(HR=2.34;95%CI:1.30-4.19,P=0.009)were significant risk factors for RFS.Additionally,pre-LT DEBTACE(HR=3.15,95%CI:1.43-6.96,P=0.004)was identified as a significant risk factor for OS.CONCLUSION DEB-TACE is a safe and efficient therapy for advanced-stage HCC and also enhances patient survival after LT.
文摘BACKGROUND The combination of transarterial chemoembolization(TACE),lenvatinib,and programmed cell death 1(PD-1)inhibitor has been widely used in the treatment of advanced hepatocellular carcinoma(HCC)and has achieved promising results.However,there are few studies comparing whether drug-eluting beads TACE(DTACE)can bring more survival benefits to patients with large HCC compared to conventional TACE(C-TACE)in this triplet therapy.AIM To compare the efficacy and adverse events(AEs)of triple therapy comprising DTACE,PD-1 inhibitors,and lenvatinib(D-TACE-P-L)and C-TACE,PD-1 inhibitors,and lenvatinib(C-TACE-P-L)in patients with large HCC(maximum diameter≥5 cm),and analyze the prognostic factors.METHODS Following a comprehensive review of our hospital’s medical records,this retrospective study included 104 patients:50 received D-TACE-P-L,and 54 received CTACE-P-L.We employed Kaplan-Meier estimation to assess the median progression-free survival(PFS)between the two groups,utilized Cox multivariate regression analysis to identify prognostic factors,and applied theχ2 test to evaluate AEs.RESULTS The objective response rate(ORR)and median PFS were significantly higher in the D-TACE-P-L group compared to the C-TACE-P-L group(ORR:66.0%vs 44.4%,P=0.027;median PFS:6.8 months vs 5.0 months,P=0.041).Cox regression analysis identified treatment option,portal vein tumor thrombus,and hepatic vein invasion as protective factors for PFS.AEs were comparable between the two CONCLUSION D-TACE-P-L may have significantly better PFS and ORR for large HCC,while exhibiting similar AEs to C-TACE-PL.
文摘We applied the discrete element method (DEM) of simulation modified by an enlarged particle model to simulate bead motion in a large bead mill. The stainless-steel bead mill has inner diameter of 102 mm and mill length of 198 mm. The bead diameter and filling ratio were fixed respectively at 0.5 mm and 85%. The agitator rotational speed was changed from 1863 to 3261 rpm. The bead motion was monitored experimentally using a high-speed video camera through a transparent mill body. For the simulation, enlarged particle sizes were set as 3-6 mm in diameter. With the DEM modified by the enlarged particle model, the motion of enlarged particles in a mill was simulated.The velocity data of the simulated enlarged particles were compared with those obtained in the experiment. The simulated velocity of the enlarged particles depends on the virtual frictional coefficient in the DEM model. The optimized value of the virtual frictional coefficient can be determined by considering the accumulated mean value. Results show that the velocity of the enlarged particles simulated increases with an increase in the optimum virtual frictional coefficient, but the simulated velocity agrees well with that determined experimentally by optimizing the virtual frictional coefficient in the simulation. The computing time in the simulation decreases with increased particle size.
基金financial support from the National Basic Research Program of China(973 Program,No.2009CB930300)
文摘The objective of this work is to construct a nanosuspension drug delivery system of probucol,a BCS II drug,in order to improve its dissolution and oral bioavailability.The wet milling procedure using planetary beads-milling equipment was utilized to grind the raw probucol to ultrafine nanoparticle/nanocrystal aqueous suspension that was further solidified by freeze-drying process.Cellulose derivatives of different substitution groups and molecular weights,including HPMC,HPC,and MC,were evaluated as the primary stabilizer of probucol nanosuspension.Ternary stabilizers system composed of a primary stabilizer(cellulose derivative,i.e.HPC),a nonionic surfactant(Pluronic R F68),and an anionic surfactant(SDS)was employed to obtain probucol nanosuspension of finer particle size and enhanced dissolution in aqueous media.The probucol nanosuspension with good physical stability showed no obvious change of particle size even after storing over 7 d at 4°C or 25°C.The solidified probucol nanosuspension with trehalose as the cryoprotectant showed the highest dissolution rate(>60%at 2 h)compared to other cryoprotectant.The in vivo pharmacokinetic evaluation indicated about 15-folds higher AUC value of the probucol nanosuspension compared to that of coarse probucol suspension after oral administration to rats.The probucol nanosuspension prepared by wet-milling and ternary stabilizers system may find wide applications for improving the dissolution and oral absorption of water-insoluble drugs.
基金Projects(51175185,50705030)supported by the National Natural Science Foundation of ChinaProject(2012ZZ0052)supported by the Fundamental Research Funds for the Central Universities,ChinaProject(9151064101000065)supported by the Natural Science Foundation of Guangdong Province,China
文摘To investigate influence of welding parameters on weld bead geometry in underwater wet flux cored arc welding (FCAW), orthogonal experiments of underwater wet FCAW were conducted in the hyperbaric chamber at water depth from 0.2 m to 60 m and mathematical models were developed by multiple curvilinear regression method from the experimental data. Sensitivity analysis was then performed to predict the bead geometry and evaluate the influence of welding parameters. The results reveal that water depth has a greater influence on bead geometry than other welding parameters when welding at a water depth less than 10 m. At a water depth deeper than 10 m, a change in travel speed affects the bead geometry more strongly than other welding parameters.
文摘This paper is part of a series addressing the urgent need for effective technologies to reduce energy demand and mitigate climate impact.This study focused on the implementation and development of dynamic insulation technology for a sustainable and energy-efficient future in the region,especially in Iraq.The study assessed the energy efficiency of dynamic insulation technology by analyzing three wallmodels(static,dynamic,and modified)during thewinter season.This paper expands the analysis to include a hot,dry summer scenario,providing valuable insights into the year-round performance of dynamic walls and enabling sustainable and energy-efficient solutions for Iraq’s climate.The study evaluates the thermal efficiency of the dynamic intake and exhaust facades during the cooling season for the city of Baghdad.The finding indicated that the dynamic intake facade reduces energy consumption by 16.3%for the dynamic wall and 17.2%for the modified dynamic wall.In addition,the dynamic exhaust front reduces energy consumption by 46%during the cooling season,with the maximum permissible exhaust air level.Dynamic insulation is suitable for hot and dry climates,improving energy consumption.
文摘A problem similar to the famous brachistochrone problem is examined in which, instead of a smooth curve, the path consists of two straight-line sections, one slant and one horizontal. The condition for minimum sliding time is investigated, producing results that are both counterintuitive and interesting.
文摘Based on the theory of stability of the liquid metal under the action of surface tension,a physical mod- el is established for the mechanisms of the bead formation deferct' humping', which is generated during high - speed welding.A boundary function is introduced to correct the model,theoretical results got by the model correspond well with the experimental phenomena. A two - dimensional conducting model is adoopted in the simulation of the temperature field during high - speed welding.Finally, the factors acting upon the stability of liquid metal are analyzed.
基金the financial support under the Short Term Grant (No.304/PKIMIA/636065)
文摘The study examined the adsorption of Pb(II) ions from aqueous solution onto chitosan, chitosan-GLA and chitosan-alginate beads. Several important parameters influencing the adsorption of Pb(II) ions such as initial pH, adsorbent dosage and different initial concentration of Pb(II) ions were evaluated. The mechanism involved during the adsorption process was explored based on ion exchange study and using spectroscopic techniques. The adsorption capacities obtained based on non–linear Langmuir isotherm for chitosan, chitosan-GLA and chitosan-alginate beads in single metal system were 34.98, 14.24 and 60.27 mg/g, respectively. However, the adsorption capacity of Pb(II) ions were reduced in the binary metal system due to the competitive adsorption between Pb(II) and Cu(II) ions. Based on the ion exchange study, the release of Ca2+, Mg2+, K+ and Na+ ions played an important role in the adsorption of Pb(II) ions by all three adsorbents but only at lower concentrations of Pb(II) ions. Infrared spectra showed that the binding between Pb(II) ions and the adsorbents involved mostly the nitrogen and oxygen atoms. All three adsorbents showed satisfactory adsorption capacities and can be considered as an efficient adsorbent for the removal of Pb(II) ions from aqueous solutions.
文摘AIM:To assess the possible effect of two different types of preoperative transcatheter arterial chemoembolization(TACE)on recurrence-free survival after liver transplantation(LT)in patients with hepatocellular carcinoma(HCC)and to analyze the effects of TACE on tumor histology.METHODS:We retrospectively analyzed the histological features of 130 HCC nodules in 63 native livers removed at transplantation.Patients who received any other type of treatment such as radiofrequency tumor ablation,percutaneous ethanol ablation or who were not treated at all were excluded.All patients in the present study were within the Milan Criteria at the last imaging findings before transplantation.Doxorubicineluting bead TACE(DEB-TACE)was performed in 22patients(38 nodules),and conventional TACE(c-TACE)in 16(25 nodules).Patients’and tumors’characteristics were retrospectively reviewed.We performed a pernodule analysis of the explanted livers to establish the mean percentage of necrosis of any nodule treated by TACE(conventional or DEB)and a per-patient analysis to establish the percentage of necrosis in the cumulative tumor area,including 21 nodules not reached by TACE.Inflammatory and fibrotic changes in the tissue surrounding the tumor nodule were analyzed and categorized as poor/absent,moderate and enhanced reaction.Uni-and multivariate analysis of risk factors for HCC-recurrence were performed.RESULTS:The number and diameter of the nodules,the time spent on the waiting list and the number of treatments were similar in the two groups.A trend towards higher appropriate response rates(necrosis≥90%)was observed in the DEB-TACE group(44.7%vs32.0%,P=0.2834).The mean percentage of necrosis in the cumulative tumor area was 58.8%±36.6%in the DEB-TACE group and 50.2%±38.1%in the c-TACE group(P=0.4856).Fibrotic and inflammatory reactions surrounding the tumor nodule were markedly more common in the DEB-TACE group(P<0.0001,for both the parameters).The three-year recurrence-free survival was higher in DEB-TACE-treated patients than in conventionally treated patients(87.4%vs 61.5%,P=0.0493).Other factors affecting recurrence-free survival included viable tumor beyond Milan Criteria on histopathological examination,the percentage of necrosis on CTA≤50%and a pre-transplant serum-fetoprotein level greater than 70 ng/mL.On multivariate analysis,the lack of treatment with DEB-TACE,high levels of-fetoprotein and viable tumor beyond Milan Criteria at histology examination were identified as independent predictors of tumor recurrence.CONCLUSION:DEB-TACE can effectively promote tumor necrosis and improves recurrence-free survival after LT in HCC.
基金Project(51504299)supported by the National Science Found for Young Scientists of ChinaProject(2012GS430101)supported by the National Science and Technology Program for Public Wellbeing,China
文摘The phosphate-embedded calcium alginate beads were successfully synthesized based on sodium alginate, calcium dihydrogen phosphate and sodium hydrogen carbonate. Scanning electron microscopy, Fourier transformed infrared (FTIR) spectroscopy and X-ray diffraction (XRD) were conducted to characterize the morphology and structure of the phosphate-embedded calcium alginate beads. The effects of pH and the initial concentration of the metal ions on Pb(II) and Cd(II) sorption by the beads were investigated. The optimal pH values for Pb(II) and Cd(II) sorption are 4.0 and 5.5, respectively. The optimal initial concentrations of Pb(II) and Cd(II) are 200 mg/L and 25 mg/L, correspondingly, and the removal efficiencies are 94.2% and 80%,respectively. The sorption mechanism is that the heavy metal ions accessed the beads firstly due to the large surface area, combinedwith OH?, and then precipitated with phosphate radical, which was proven by FTIR and XRD. The sorption of Pb(II) and Cd(II) isfitted to Langmuir isotherm model with R2 values of 0.9957 and 0.988, respectively. The sorption capacities of Pb(II) and Cd(II) are263.16 mg/g and 82.64 mg/g, respectively. The results indicate that the phosphate-embedded calcium alginate beads could be appliedto treating Pb(II)/Cd(II)-containing wastewater and it could be implied that the synthesized beads also could be used as a kind of soil ameliorant for remediation of the heavy metal contaminated paddy soil.