The random models of open-cell foams that can reflect the actual cell geometrical properties are constructed with the Voronoi technique. The compression process of elastic open-cell foams is simulated with the nonline...The random models of open-cell foams that can reflect the actual cell geometrical properties are constructed with the Voronoi technique. The compression process of elastic open-cell foams is simulated with the nonlinear calculation module of finite element analysis program. In order to get the general results applicable to this kind of materials, the dimensionless compressive stress is used and the stress-strain curves of foam models with different geometrical properties are obtained. Then, the influences of open-cell geometrical properties, including the shape of strut cross section, relative density and cell shape irregularity, on the compressive nonlinear mechani- cal performance are analyzed. In addition, the numerical results are compared with the predicted results of cubic staggering model. Nu- merical results indicate that the simulated results reflect the compressive process of foams quite well and the geometrical properties of cell have significant influences on the nonlinear mechanical behavior of foams.展开更多
Based on the elongated Kelvin model, the effect of microstructure on the uniaxial strength asymmetry of open-cell foams is investigated. The results indicate that this asymmetry depends on the relative density, the so...Based on the elongated Kelvin model, the effect of microstructure on the uniaxial strength asymmetry of open-cell foams is investigated. The results indicate that this asymmetry depends on the relative density, the solid material, the cell morphology, and the strut geometry of open-cell foams. Even though the solid material has the same tensile and compressive strength, the tensile and compressive strength of open-cell foams with asymmetrical sectional struts are still different. In addition, with the increasing degree of anisotropy, the uniaxial strength as well as the strength asymmetry increases in the rise direction but reduces in the transverse direction. Moreover, the plastic collapse ratio between two directions is verified to depend mainly on the cell morphology. The predicted results are compared with Gibson and Ashby＇s theoretical results as well as the experimental data reported in the literature, which validates that the elongated Kelvin model is accurate in explaining the strength asymmetry presented in realistic open-cell foams.展开更多
The open-cell Al foam core sandwiches（AFCSs） were successfully fabricated by using a specially designed Zn-Al-Cu based filler alloy via vibration aided liquid phase bonding method.The effects of the vibration on the...The open-cell Al foam core sandwiches（AFCSs） were successfully fabricated by using a specially designed Zn-Al-Cu based filler alloy via vibration aided liquid phase bonding method.The effects of the vibration on the bonding seam were investigated and the bonding strength between Al foam core and solid Al alloy face sheet was tested by shearing tests.The results show that vibration can significantly improve the quality of the bonding and the shearing strength of the bonding seam,which implies that this joining method has a good potential in practical applications.展开更多
The open-cell structure foams of linear low-density polyethylene（LLDPE） and linear low-density polyethylene（LLDPE）/multi-wall carbon nanotubes（MWCNTs） composites are prepared by using supercritical carbon dioxid...The open-cell structure foams of linear low-density polyethylene（LLDPE） and linear low-density polyethylene（LLDPE）/multi-wall carbon nanotubes（MWCNTs） composites are prepared by using supercritical carbon dioxide（sc-CO2）as a foaming agent. The effects of processing parameters（foaming temperature, saturation pressure, and depressurization rate） and the addition of MWCNTs on the evolution of cell opening are studied systematically. For LLDPE foaming, the foaming temperature and saturation pressure are two key factors for preparing open-cell foams. An increase in temperature and pressure promotes both the cell wall thinning and cell rupture, because a high temperature results in a decrease in the viscosity of the polymer, and a high pressure leads to a larger amount of cell nucleation. Moreover, for the given temperature and pressure, the high pressurization rate results in a high pressure gradient, favoring cell rupture. For LLDPE/MWCNTs foaming, the addition of MWCNTs not only promotes the cell heterogeneous nucleation, but also prevents the cell collapse during cell opening, which is critical to achieve the open-cell structures with small cell size and high cell density.展开更多
Foamed zinc was prepared by infiltration casting process.The mechanical properties and corrosion resistance of the samples were studied,and the feasibility of the foamed zinc as a bone implant material was discussed.A...Foamed zinc was prepared by infiltration casting process.The mechanical properties and corrosion resistance of the samples were studied,and the feasibility of the foamed zinc as a bone implant material was discussed.All the compression stress-strain curves of open-cell zinc foams with various cell size(1-4 mm)and porosity(55%-67%)show three stages:elastic stage,plastic stage,and densification stage.The compression strength increases with decreasing density.The smooth stress-strain response indicates a progressively deformation of open-cell zinc foam.In addition,the cell wall or edge bending and fracture are the dominated mechanisms for failure of open cell zinc foam.The immersion test for determining the corrosion rate of open cell zinc foam was conducted in simulated body fluid.It was found that zinc foam with a small cell size and high porosity showed a higher corrosion rate.In addition,open-cell zinc foams can effectively induce Ca-P deposition in immersion tests,showing good bioactivity.Therefore,the open cell zinc foam prepared in this experiment has a good potential application as a human bone substitute material.展开更多
The aluminum open cell foams have been prepared by the conventional precision casting method to investigate the thermal and acoustic properties.A water heating system and silencers were organized as a first step for i...The aluminum open cell foams have been prepared by the conventional precision casting method to investigate the thermal and acoustic properties.A water heating system and silencers were organized as a first step for its applications.The temperature increase between the top and bottom of the foam became larger as the cell size increased in the heat transfer measurement.Sound absorption ratio of the close cell foams was 60%-100%, whereas the open cell aluminum foam showed only 10%-20% of sound absorption at low frequency.When the prototype electric water heater manufactured by combining aluminum open cell foam with a heater was heated to 100-400℃,the highest temperature of water was in the range of 16-46~C.This suggests that there could be potential for this type of heater to be used as a commercial electric water heater.Sound silencer made with the aluminum open cell foam was applied to exit of exhaustion side at air pressure line.Sound silencing effect of open-celled aluminum foam showed that the noise level went down by introducing smaller cell size foam.展开更多
Metal foams are a new kind of materials with low densities and novel physical, mechanical, thermal, electrical and acoustic properties. They can be divided into closed and open cell structures. In this paper the open ...Metal foams are a new kind of materials with low densities and novel physical, mechanical, thermal, electrical and acoustic properties. They can be divided into closed and open cell structures. In this paper the open cell structures, called sponges, were treated. A new technique to manufacture sponges by plaster investment casting was described. Experimental results show that it is essential to make a sound plaster mould by casting plaster slurry into the polyurethane foams and infiltrate the open channels of the baked plaster mold by molten metal. The optimal processes include plaster slurry preparation, plaster mold baking, and molten metal infiltration. The sponge sample with porosity of 97% is presented.展开更多
In this study, Y-and Ce-modified Cr coatings applied by pack cementation method were prepared on the surface of open-cell nickel-based alloy foam. The morphologies and microstructures of Y- and Ce-modified Cr coatings...In this study, Y-and Ce-modified Cr coatings applied by pack cementation method were prepared on the surface of open-cell nickel-based alloy foam. The morphologies and microstructures of Y- and Ce-modified Cr coatings with various Y and Ce contents were investigated in detail. Then, the effects of Y and Ce addition on the mechanical properties of open-cell nickel-based alloy foams were analyzed and compared. Simultaneously, the energy absorption capacity and energy absorption efficiency of the Y- and Ce-modified Cr coated alloy foams were discussed and compared at the room and high temperatures. The results show that Cr coatings containing minor amounts of rare earth element （Y and Ce） are well adhered to the nickel-based foam struts. Especially, the microstructure of the 2 wt% Ce-modified Cr coating is denser and uniform. In addition, the compressive strength and plateau stress of Y- and Ce-modified Cr coated alloy foams firstly increase and then decrease by increasing the Y and Ce contents at room and high temperatures. The energy absorption capacity of Y/Cr and Ce/Cr coated alloy foams increases linearly with the strains increasing. The Ce/Cr coated alloy foams can absorb more energy than Y/Cr coated alloy foams in the plateau and densification regions at room temperature. Compared to those at room temperature, the Y- and Ce-modified Cr coated alloy foams show higher energy absorption efficiency when deforma- tion within 10%-30% at high temperature.展开更多
This manuscript deals with the electro-deposition of Cu on aluminum foams. Metallic foams are highly porous materials which present complex structure of three-dimensional open cells. This aspect causes strong limitati...This manuscript deals with the electro-deposition of Cu on aluminum foams. Metallic foams are highly porous materials which present complex structure of three-dimensional open cells. This aspect causes strong limitations in mass transport due to electro-deposition technology. Experimental tests were performed to study the influence of the operational parameters on the overall performance of the coated aluminum foams. The experimental findings revealed that the manufactured metal foams were characterized by a high thermal conductivity and low process costs, making these materials very promising in many technological fields. On the basis of the experimental results, analytical models are proposed to predict the quantity and the quality characteristics of the coating.展开更多
A broadband microstrip patch antenna, loaded E-U-shaped open slot on backward of radiating layer is proposed and experimentally investigated. The antenna employs a foam-filled dielectric substrate, whose dielectric co...A broadband microstrip patch antenna, loaded E-U-shaped open slot on backward of radiating layer is proposed and experimentally investigated. The antenna employs a foam-filled dielectric substrate, whose dielectric constant is within the lower end of the range. The proposed antenna has been designed for electromagnetic analysis including the impedance bandwidth, reflection coefficient, radiation pattern, and antenna gain. The open slot is loaded on the back radiated layer, which is perpendicular to the radiating edge of the oblong microstrip patch component, where the symmetric line feed is selected. This new technique used to increase the bandwidth and the gain of antenna through increasing current path by slot location, width and length on backward of radiating Layer. The main structure in this research was a single microstrip patch antenna planar with three layers operating at two resonant frequencies 4.440 GHz and 5.833 GHz. All the simulated results are confirmed by two packages of electromagnetism simulation. An impedance bandwidth (S11 ≤ ?10 dB) up to about 41.03% and 30.61% is achieved by individually optimizing its parameters. The antenna exhibits nearly stable radiation pattern with a maximum gains of 8.789 dBi and 9.966 dBi, which is suitable for Wi-Fi Band, satellite communications, and wireless presented. Whereas the results before this design that we have a proof of publication are 36.17% and 28.43%.展开更多
An open-cell aluminum foam filled with silicate rubber (AFFSR) was fabricated by infiltration of the liquid silicate rubber into the open-cell aluminum foam. The experiments were carried out to investigate the compres...An open-cell aluminum foam filled with silicate rubber (AFFSR) was fabricated by infiltration of the liquid silicate rubber into the open-cell aluminum foam. The experiments were carried out to investigate the compressive behavior and energy absorption characteristics of the material. It is found that the stress—strain response of the AFFSR exhibits five regions including two plateau regimes, which is quite different from the stress—strain curves of many unfilled metallic foams that usually exhibit three distinct regions. The plastic deformation of the AFFSR is prolonged because of the filled silicate rubber, compared with the aluminum foam without such a filler. The AFFSR also exhibits a higher energy capacity than the aluminum foam without filler. Additionally, for the prolonged plateau region in the stress—strain curve, the energy absorption efficiency of the AFFSR maintains a high level (above 0.6) over a wide strain range from 3% to 60%.展开更多
In this study, a design of experiments (DoE) approach was used to develop a PLA open-cell foam morphology using the compression molding technique. The effect of three molding parameters (foaming time, mold opening tem...In this study, a design of experiments (DoE) approach was used to develop a PLA open-cell foam morphology using the compression molding technique. The effect of three molding parameters (foaming time, mold opening temperature, and weight concentration of the ADA blowing agent) on the cellular structure was investigated. A regression equation relating the average cell size to the above three processing parameters was developed from the DoE and the analysis of variance (ANOVA) was used to find the best dimensional fitting parameters based on the experimental data. With the help of the DoE technique, we were able to develop various foam morphologies having different average cell size distribution levels, which is important in the development of open-cell PLA scaffolds for bone regeneration for which the control of cell morphology is crucial for osteoblasts proliferation. For example, at a constant ADA weight concentration of 5.95 wt%, we were able to develop a narrow average cell size distribution ranging between 275 and 300 μm by varying the mold opening temperature between 106°C and 112°C, while maintaining the foaming time constant at 8 min, or by varying the mold foaming time between 6 and 11 min and maintaining the mold opening temperature at 109°C.展开更多
目的探讨射频消融(RFA)联合点状剥脱及泡沫硬化剂闭合术治疗小隐静脉曲张的临床疗效。方法回顾性分析2022年1月至2023年12月浙江省人民医院血管外科收治的50例原发性小隐静脉曲张手术患者资料。按术式分为射频组(n=25,行小隐静脉RFA联...目的探讨射频消融(RFA)联合点状剥脱及泡沫硬化剂闭合术治疗小隐静脉曲张的临床疗效。方法回顾性分析2022年1月至2023年12月浙江省人民医院血管外科收治的50例原发性小隐静脉曲张手术患者资料。按术式分为射频组(n=25,行小隐静脉RFA联合点状剥脱及泡沫硬化剂闭合术)和抽剥组(n=25,行小隐静脉高位结扎联合点状剥脱及泡沫硬化剂闭合术)。比较两组患者手术指标(手术时间、术中出血量、术后住院时间)、静脉临床严重程度评分(VCSS)、术后24 h视觉模拟评分(VAS)、术后并发症(感觉异常、皮下硬结、皮下血肿、皮肤灼伤、皮肤瘀斑、深静脉血栓形成、血栓性静脉炎及切口感染)及术后1、6、12个月复发率。结果射频组在手术时间、术中出血量、术后24 h VAS评分及术后住院时间方面均短于/低于抽剥组(P<0.05)。两组患者术后VCSS评分均较术前显著降低(P<0.05),但组间差异无统计学意义(P>0.05)。两组术后并发症总发生率及复发率比较,差异均无统计学意义(P>0.05)。结论相较于传统高位结扎抽剥术,射频消融术联合点状剥脱及泡沫硬化剂闭合术治疗小隐静脉曲张具有手术时间短、创伤小、术后疼痛轻、恢复快的优势,其安全性与近期疗效相当。远期疗效及安全性需扩大样本量并进行长期随访进一步验证。展开更多
基金National Natural Science Foundation of China (10572013) ECB Foundation (XK100060522)
文摘The random models of open-cell foams that can reflect the actual cell geometrical properties are constructed with the Voronoi technique. The compression process of elastic open-cell foams is simulated with the nonlinear calculation module of finite element analysis program. In order to get the general results applicable to this kind of materials, the dimensionless compressive stress is used and the stress-strain curves of foam models with different geometrical properties are obtained. Then, the influences of open-cell geometrical properties, including the shape of strut cross section, relative density and cell shape irregularity, on the compressive nonlinear mechani- cal performance are analyzed. In addition, the numerical results are compared with the predicted results of cubic staggering model. Nu- merical results indicate that the simulated results reflect the compressive process of foams quite well and the geometrical properties of cell have significant influences on the nonlinear mechanical behavior of foams.
基金Project supported by the National Natural Science Foundation of China(Nos.11472025 and 11272030)
文摘Based on the elongated Kelvin model, the effect of microstructure on the uniaxial strength asymmetry of open-cell foams is investigated. The results indicate that this asymmetry depends on the relative density, the solid material, the cell morphology, and the strut geometry of open-cell foams. Even though the solid material has the same tensile and compressive strength, the tensile and compressive strength of open-cell foams with asymmetrical sectional struts are still different. In addition, with the increasing degree of anisotropy, the uniaxial strength as well as the strength asymmetry increases in the rise direction but reduces in the transverse direction. Moreover, the plastic collapse ratio between two directions is verified to depend mainly on the cell morphology. The predicted results are compared with Gibson and Ashby＇s theoretical results as well as the experimental data reported in the literature, which validates that the elongated Kelvin model is accurate in explaining the strength asymmetry presented in realistic open-cell foams.
基金support provided by the National Program on Key Basic Research Project of China (No. 2006CB601201)supports from the Research Fund for Doctoral Program of Higher Education of China (No. 200802941010)+1 种基金the Natural Science Foundation of Hohai University (No. 2008428011)the Scientific Research Startup Fund of Hohai University(No. 2084140801109)
文摘The open-cell Al foam core sandwiches（AFCSs） were successfully fabricated by using a specially designed Zn-Al-Cu based filler alloy via vibration aided liquid phase bonding method.The effects of the vibration on the bonding seam were investigated and the bonding strength between Al foam core and solid Al alloy face sheet was tested by shearing tests.The results show that vibration can significantly improve the quality of the bonding and the shearing strength of the bonding seam,which implies that this joining method has a good potential in practical applications.
基金financially supported by the National Natural Science Foundation of China(Nos.21306090 and 51403110)Scientific Research Fund of Zhejiang Provincial Education Department(Nos.Y201430774 and Y201327472)K.C.Wong Magna Fund in Ningbo University
文摘The open-cell structure foams of linear low-density polyethylene（LLDPE） and linear low-density polyethylene（LLDPE）/multi-wall carbon nanotubes（MWCNTs） composites are prepared by using supercritical carbon dioxide（sc-CO2）as a foaming agent. The effects of processing parameters（foaming temperature, saturation pressure, and depressurization rate） and the addition of MWCNTs on the evolution of cell opening are studied systematically. For LLDPE foaming, the foaming temperature and saturation pressure are two key factors for preparing open-cell foams. An increase in temperature and pressure promotes both the cell wall thinning and cell rupture, because a high temperature results in a decrease in the viscosity of the polymer, and a high pressure leads to a larger amount of cell nucleation. Moreover, for the given temperature and pressure, the high pressurization rate results in a high pressure gradient, favoring cell rupture. For LLDPE/MWCNTs foaming, the addition of MWCNTs not only promotes the cell heterogeneous nucleation, but also prevents the cell collapse during cell opening, which is critical to achieve the open-cell structures with small cell size and high cell density.
基金Key Research and Development Program of Liaoning Province(2019JH2/10100008)the Plan for Innovative Talents in Liaoning Higher Education Institutions(LR2018011)the Plan for Young and Middle-aged Science and Technology Innovation Talent of Shenyang(RC170204).
文摘Foamed zinc was prepared by infiltration casting process.The mechanical properties and corrosion resistance of the samples were studied,and the feasibility of the foamed zinc as a bone implant material was discussed.All the compression stress-strain curves of open-cell zinc foams with various cell size(1-4 mm)and porosity(55%-67%)show three stages:elastic stage,plastic stage,and densification stage.The compression strength increases with decreasing density.The smooth stress-strain response indicates a progressively deformation of open-cell zinc foam.In addition,the cell wall or edge bending and fracture are the dominated mechanisms for failure of open cell zinc foam.The immersion test for determining the corrosion rate of open cell zinc foam was conducted in simulated body fluid.It was found that zinc foam with a small cell size and high porosity showed a higher corrosion rate.In addition,open-cell zinc foams can effectively induce Ca-P deposition in immersion tests,showing good bioactivity.Therefore,the open cell zinc foam prepared in this experiment has a good potential application as a human bone substitute material.
文摘The aluminum open cell foams have been prepared by the conventional precision casting method to investigate the thermal and acoustic properties.A water heating system and silencers were organized as a first step for its applications.The temperature increase between the top and bottom of the foam became larger as the cell size increased in the heat transfer measurement.Sound absorption ratio of the close cell foams was 60%-100%, whereas the open cell aluminum foam showed only 10%-20% of sound absorption at low frequency.When the prototype electric water heater manufactured by combining aluminum open cell foam with a heater was heated to 100-400℃,the highest temperature of water was in the range of 16-46~C.This suggests that there could be potential for this type of heater to be used as a commercial electric water heater.Sound silencer made with the aluminum open cell foam was applied to exit of exhaustion side at air pressure line.Sound silencing effect of open-celled aluminum foam showed that the noise level went down by introducing smaller cell size foam.
文摘Metal foams are a new kind of materials with low densities and novel physical, mechanical, thermal, electrical and acoustic properties. They can be divided into closed and open cell structures. In this paper the open cell structures, called sponges, were treated. A new technique to manufacture sponges by plaster investment casting was described. Experimental results show that it is essential to make a sound plaster mould by casting plaster slurry into the polyurethane foams and infiltrate the open channels of the baked plaster mold by molten metal. The optimal processes include plaster slurry preparation, plaster mold baking, and molten metal infiltration. The sponge sample with porosity of 97% is presented.
基金financially supported by the National Natural Science Foundation of China (Nos.51501133 and 51405358)the China Automobile Industry Innovation and Development Joint Fund (No.U1564202)+1 种基金the Natural Science Foundation of Hubei Province (No.2016CFC773)the State Key Laboratory of Advanced Welding and Joining,Harbin Institute of Technology (No.AWJ-M16-11)
文摘In this study, Y-and Ce-modified Cr coatings applied by pack cementation method were prepared on the surface of open-cell nickel-based alloy foam. The morphologies and microstructures of Y- and Ce-modified Cr coatings with various Y and Ce contents were investigated in detail. Then, the effects of Y and Ce addition on the mechanical properties of open-cell nickel-based alloy foams were analyzed and compared. Simultaneously, the energy absorption capacity and energy absorption efficiency of the Y- and Ce-modified Cr coated alloy foams were discussed and compared at the room and high temperatures. The results show that Cr coatings containing minor amounts of rare earth element （Y and Ce） are well adhered to the nickel-based foam struts. Especially, the microstructure of the 2 wt% Ce-modified Cr coating is denser and uniform. In addition, the compressive strength and plateau stress of Y- and Ce-modified Cr coated alloy foams firstly increase and then decrease by increasing the Y and Ce contents at room and high temperatures. The energy absorption capacity of Y/Cr and Ce/Cr coated alloy foams increases linearly with the strains increasing. The Ce/Cr coated alloy foams can absorb more energy than Y/Cr coated alloy foams in the plateau and densification regions at room temperature. Compared to those at room temperature, the Y- and Ce-modified Cr coated alloy foams show higher energy absorption efficiency when deforma- tion within 10%-30% at high temperature.
文摘This manuscript deals with the electro-deposition of Cu on aluminum foams. Metallic foams are highly porous materials which present complex structure of three-dimensional open cells. This aspect causes strong limitations in mass transport due to electro-deposition technology. Experimental tests were performed to study the influence of the operational parameters on the overall performance of the coated aluminum foams. The experimental findings revealed that the manufactured metal foams were characterized by a high thermal conductivity and low process costs, making these materials very promising in many technological fields. On the basis of the experimental results, analytical models are proposed to predict the quantity and the quality characteristics of the coating.
文摘A broadband microstrip patch antenna, loaded E-U-shaped open slot on backward of radiating layer is proposed and experimentally investigated. The antenna employs a foam-filled dielectric substrate, whose dielectric constant is within the lower end of the range. The proposed antenna has been designed for electromagnetic analysis including the impedance bandwidth, reflection coefficient, radiation pattern, and antenna gain. The open slot is loaded on the back radiated layer, which is perpendicular to the radiating edge of the oblong microstrip patch component, where the symmetric line feed is selected. This new technique used to increase the bandwidth and the gain of antenna through increasing current path by slot location, width and length on backward of radiating Layer. The main structure in this research was a single microstrip patch antenna planar with three layers operating at two resonant frequencies 4.440 GHz and 5.833 GHz. All the simulated results are confirmed by two packages of electromagnetism simulation. An impedance bandwidth (S11 ≤ ?10 dB) up to about 41.03% and 30.61% is achieved by individually optimizing its parameters. The antenna exhibits nearly stable radiation pattern with a maximum gains of 8.789 dBi and 9.966 dBi, which is suitable for Wi-Fi Band, satellite communications, and wireless presented. Whereas the results before this design that we have a proof of publication are 36.17% and 28.43%.
文摘An open-cell aluminum foam filled with silicate rubber (AFFSR) was fabricated by infiltration of the liquid silicate rubber into the open-cell aluminum foam. The experiments were carried out to investigate the compressive behavior and energy absorption characteristics of the material. It is found that the stress—strain response of the AFFSR exhibits five regions including two plateau regimes, which is quite different from the stress—strain curves of many unfilled metallic foams that usually exhibit three distinct regions. The plastic deformation of the AFFSR is prolonged because of the filled silicate rubber, compared with the aluminum foam without such a filler. The AFFSR also exhibits a higher energy capacity than the aluminum foam without filler. Additionally, for the prolonged plateau region in the stress—strain curve, the energy absorption efficiency of the AFFSR maintains a high level (above 0.6) over a wide strain range from 3% to 60%.
文摘In this study, a design of experiments (DoE) approach was used to develop a PLA open-cell foam morphology using the compression molding technique. The effect of three molding parameters (foaming time, mold opening temperature, and weight concentration of the ADA blowing agent) on the cellular structure was investigated. A regression equation relating the average cell size to the above three processing parameters was developed from the DoE and the analysis of variance (ANOVA) was used to find the best dimensional fitting parameters based on the experimental data. With the help of the DoE technique, we were able to develop various foam morphologies having different average cell size distribution levels, which is important in the development of open-cell PLA scaffolds for bone regeneration for which the control of cell morphology is crucial for osteoblasts proliferation. For example, at a constant ADA weight concentration of 5.95 wt%, we were able to develop a narrow average cell size distribution ranging between 275 and 300 μm by varying the mold opening temperature between 106°C and 112°C, while maintaining the foaming time constant at 8 min, or by varying the mold foaming time between 6 and 11 min and maintaining the mold opening temperature at 109°C.
文摘目的探讨射频消融(RFA)联合点状剥脱及泡沫硬化剂闭合术治疗小隐静脉曲张的临床疗效。方法回顾性分析2022年1月至2023年12月浙江省人民医院血管外科收治的50例原发性小隐静脉曲张手术患者资料。按术式分为射频组(n=25,行小隐静脉RFA联合点状剥脱及泡沫硬化剂闭合术)和抽剥组(n=25,行小隐静脉高位结扎联合点状剥脱及泡沫硬化剂闭合术)。比较两组患者手术指标(手术时间、术中出血量、术后住院时间)、静脉临床严重程度评分(VCSS)、术后24 h视觉模拟评分(VAS)、术后并发症(感觉异常、皮下硬结、皮下血肿、皮肤灼伤、皮肤瘀斑、深静脉血栓形成、血栓性静脉炎及切口感染)及术后1、6、12个月复发率。结果射频组在手术时间、术中出血量、术后24 h VAS评分及术后住院时间方面均短于/低于抽剥组(P<0.05)。两组患者术后VCSS评分均较术前显著降低(P<0.05),但组间差异无统计学意义(P>0.05)。两组术后并发症总发生率及复发率比较,差异均无统计学意义(P>0.05)。结论相较于传统高位结扎抽剥术,射频消融术联合点状剥脱及泡沫硬化剂闭合术治疗小隐静脉曲张具有手术时间短、创伤小、术后疼痛轻、恢复快的优势,其安全性与近期疗效相当。远期疗效及安全性需扩大样本量并进行长期随访进一步验证。
