期刊文献+
共找到54篇文章
< 1 2 3 >
每页显示 20 50 100
Structure based release kinetics analysis of doxazosin mesylate sustained-release tablets using micro-computed tomography
1
作者 Qian Liu Mengqing Zan +8 位作者 Hanhan Huang Hai Su Wenjing Zhang Lingyun Ma Guangchao Zhang Zunjian Zhang Jiwen Zhang Jianzhao Niu Mingdi Xu 《Asian Journal of Pharmaceutical Sciences》 SCIE CAS 2024年第6期154-162,共9页
The structures of solid dosage forms determine their release behaviors and are critical attributes for the design and evaluation of the solid dosage forms.Here,the 3D structures of doxazosin mesylate sustained-release... The structures of solid dosage forms determine their release behaviors and are critical attributes for the design and evaluation of the solid dosage forms.Here,the 3D structures of doxazosin mesylate sustained-release tablets were parallelly assessed by micro-computed tomography(micro-CT).There were no significant differences observed in the release profiles between the RLD and the generic formulation in the conventional dissolution,but the generic preparation released slightly faster in media with ethanol during an alcohol-induced dose-dumping test.With their 3D structures obtained via micro-CT determination,the unique release behaviors of both RLD and the generic were investigated to reveal the effects of internal fine structure on the release kinetics.The structural parameters for both preparations were similar in conventional dissolution test,while the dissolutions in ethanol media showed some distinctions between RLD and generic preparations due to their static and dynamic structures.Furthermore,the findings revealed that the presence of ethanol accelerated dissolution and induced changes in internal structure of both RLD and generic preparations.Moreover,structure parameters like volume and area of outer contour,remaining solid volume and cavity volumewere not equivalent between the two formulations in 40%ethanol.In conclusion,the structure data obtained from this study provided valuable insights into the diverse release behaviors observed in various modified-release formulations in drug development and quality control. 展开更多
关键词 Doxazosin mesylate sustained-release tablets Osmotic pump tablets micro-computed tomography Three-dimensional structures ETHANOL
暂未订购
Micro-Computed Tomography Applications in Dentistry
2
作者 Ahmad Assari Maha Al Bukairi Reema Al Saif 《Open Journal of Stomatology》 2024年第1期32-41,共10页
Micro-computed tomography (MCT) encompasses two primary scanning options: ex-vivo and in-vivo imaging. Ex-vivo scanning involves the examination of extracted teeth or dental specimens, allowing for detailed analyses o... Micro-computed tomography (MCT) encompasses two primary scanning options: ex-vivo and in-vivo imaging. Ex-vivo scanning involves the examination of extracted teeth or dental specimens, allowing for detailed analyses of the microarchitecture of mineralized tissue. By analyzing the microarchitecture of dental tissues, MCT can provide valuable information about bone density, porosity, and microstructural changes, contributing to a better understanding of disease progression and treatment outcomes. Moreover, MCT facilitates the quantification of dental parameters, such as bone volume, trabecular thickness, and connectivity density, which are crucial for evaluating the efficacy of dental interventions. This present study aims to comprehensively review and explore the applications of MCT in dentistry and highlight its potential in advancing research and clinical practice. The results depicted that the quantitative approach of MCT enhances the precision and reliability of dental research. Researchers and clinicians can make evidence-based decisions regarding treatment strategies and patient management, relying on quantifiable data provided by MCT. The applications of MCT in dentistry extend beyond research, with potential clinical implications in fields such as dental implantology and endodontics. MCT is expected to play an increasingly significant role in enhancing our understanding of dental pathologies, improving treatment outcomes, and ultimately, benefiting patient care in the field of dentistry. 展开更多
关键词 Clinical Practice DENTISTRY Ex-Vivo Scanning micro-computed Tomography
暂未订购
Comparative study of chitosan/fibroin–hydroxyapatite and collagen membranes for guided bone regeneration in rat calvarial defects: micro-computed tomography analysis 被引量:16
3
作者 Jae Min Song Sang Hun Shin +4 位作者 Yong Deok Kim Jae Yeol Lee Young Jae Baek Sang Yong Yoon Hong Sung Kim 《International Journal of Oral Science》 SCIE CAS CSCD 2014年第2期87-93,共7页
This study aimed to utilize micro-computed tomography (micro-CT) analysis to compare new bone formation in rat calvarial defects using chitosan/fibroin-hydroxyapatite (CFB-HAP) or collagen (Bio-Gide) membranes. ... This study aimed to utilize micro-computed tomography (micro-CT) analysis to compare new bone formation in rat calvarial defects using chitosan/fibroin-hydroxyapatite (CFB-HAP) or collagen (Bio-Gide) membranes. Fifty-four (54) rats were studied. A circular bony defect (8 mm diameter) was formed in the centre of the calvaria using a trephine bur. The CFB-HAP membrane was prepared by thermally induced phase separation. In the experimental group (n= 18), the CFB-HAP membrane was used to cover the bony defect, and in the control group (n= 18), a resorbable collagen membrane (Bio-Gide) was used. In the negative control group (n= 18), no membrane was used. In each group, six animals were euthanized at 2, 4 and 8 weeks after surgery. The specimens were then analysed using micro-CT. There were significant differences in bone volume (BV) and bone mineral density (BMD) (P〈O.05) between the negative control group and the membrane groups. However, there were no significant differences between the CFB-HAP group and the collagen group. We concluded that the CFB-HAP membrane has significant potential as a guided bone regeneration (GBR) membrane. 展开更多
关键词 chitosan/fibroin-hydroxyapatite collagen membrane guided bone regeneration micro-computed tomography rat calva rial defect
暂未订购
Investigating microstructure of Longmaxi shale in Shizhu area,Sichuan Basin, by optical microscopy, scanning electron microscopy and micro-computed tomography 被引量:9
4
作者 Yu Wang Li-Hua Wang +3 位作者 Jian-Qiang Wang Zheng Jiang Chan Jin Yan-Fei Wang 《Nuclear Science and Techniques》 SCIE CAS CSCD 2017年第11期226-235,共10页
Microstructure of shale formation is the key to understanding its petrophysical and chemical properties.Optical microscopy, scanning electron microscopy and micro-computed tomography(μ-CT) have been combined for char... Microstructure of shale formation is the key to understanding its petrophysical and chemical properties.Optical microscopy, scanning electron microscopy and micro-computed tomography(μ-CT) have been combined for characterization of microstructure of Longmaxi(LMX)shale from Shizhu area, Sichan Basin. The results indicate that laminated LMX shale consists of mineral matrix-rich layers and organic matter(OM)-rich layers at micrometer scale in two and three dimensions. Mineral matrix layers,mainly consisting of interparticle pores and intraplatelet pores, are approximately parallel to the bedding plane.Pyrite-rich layer, mainly containing intercrystalline pores,shows a strong preferred orientation parallel to the bedding plane. OM-rich layer, mainly containing OM pores, seems to be discontinuous. In addition, intercrystalline pores are enriched in some layers, while OM pores are distributed irregularly in matrix layers. This vertical heterogeneity of pore microscopic structures in LMX shale is of great importance to understand its petrophysical and chemical properties. 展开更多
关键词 micro-computed TOMOGRAPHY PORE MICROSTRUCTURE HETEROGENEITY Matrix layers Longmaxi SHALE
在线阅读 下载PDF
Nondestructive Skeletal Imaging of Hyla suweonensis Using Micro-Computed Tomography 被引量:1
5
作者 Eunbin KIM Hacheol SUNG +3 位作者 Donghyun LEE Geunjoong KIM Dongha NAM Etmgsam KIM 《Asian Herpetological Research》 SCIE CSCD 2017年第4期235-243,共9页
We successfully obtained 3D skeletal images of Hyla suweonensis, employing a nondestructive method by applying appropriate anesthesia and limiting the radiation dose. H. suweonensis is a tree frog endemic to Korea and... We successfully obtained 3D skeletal images of Hyla suweonensis, employing a nondestructive method by applying appropriate anesthesia and limiting the radiation dose. H. suweonensis is a tree frog endemic to Korea and is on the list of endangered species. Previous studies have employed caliper-based measurements and two-dimensional (2D) X-ray imaging for anatomical analyses of the skeletal system or bone types of H. suweonensis. In this work we reconstructed three-dimensional (3D) skeletal images of H. suweonensis, utilizing a nondestructive micro-computed tomography (micro-CT) with a short scan and low radiation dose (i.e. 4 min and 0.16 Gy). Importantly, our approach can be applied to the imaging of 3D skeletal systems of other endangered frog species, allowing both versatile and high contrast images of anatomical structures without causing any significant damages to the living animal. 展开更多
关键词 Hyla suweonensis micro-computed tomography 3D skeletal structure Nondestructive imaging Endangered species Radiation dose.
原文传递
Contrast-enhanced micro-computed tomography using Exi Tron nano6000 for assessment of liver injury
6
作者 Xiang-Wei Hua Tian-Fei Lu +6 位作者 Da-Wei Li Wei-Gang Wang Jun Li Zhen-Ze Liu Wei-Wei Lin Jian-Jun Zhang Qiang Xia 《World Journal of Gastroenterology》 SCIE CAS 2015年第26期8043-8051,共9页
AIM: To explore the potential of contrast-enhanced computed tomography(CECT) using Exi Tron nano6000 for assessment of liver lesions in mouse models.METHODS: Three mouse models of liver lesions were used: bile duct li... AIM: To explore the potential of contrast-enhanced computed tomography(CECT) using Exi Tron nano6000 for assessment of liver lesions in mouse models.METHODS: Three mouse models of liver lesions were used: bile duct ligation(BDL),lipopolysaccharide(LPS)/D-galactosamine(D-Gal N),and alcohol.After injection with the contrast agent Exi Tron nano6000,the mice were scanned with micro-CT.Liver lesions were evaluated using CECT images,hematoxylin and eosin staining,and serum aminotransferase levels.Macrophage distribution in the injury models was shown by immunohistochemical staining of CD68.The in vitro studies measured the densities of RAW264.7 under different conditions by CECT.RESULTS: In the in vitro studies,CECT provided specific and strong contrast enhancement of liver in mice.CECT could present heterogeneous images anddensities of injured livers induced by BDL,LPS/D-Gal N,and alcohol.The liver histology and immunochemistry of CD68 demonstrated that both dilated biliary tracts and necrosis in the injured livers could lead to the heterogeneous distribution of macrophages.The in vitro study showed that the RAW264.7 cell masses had higher densities after LPS activation.CONCLUSION: Micro-CT with the contrast agent Exi Tron nano6000 is feasible for detecting various liver lesions by emphasizing the heterogeneous textures and densities of CECT images. 展开更多
关键词 micro-computed TOMOGRAPHY ExiTronNano6000 LIVER INJURY
暂未订购
Microstructure Study of Normal Lunates with Micro-computed Tomography
7
作者 肖滋润 熊革 +2 位作者 shi-gong guo 杜传超 张友乐 《Journal of Huazhong University of Science and Technology(Medical Sciences)》 SCIE CAS 2017年第3期384-389,共6页
In order to study the microstructure characteristics of normal lunate bones, eight fresh cadaver normal lunates were scanned with micro-computed tomography. High-resolution images of the micro-structure of normal luna... In order to study the microstructure characteristics of normal lunate bones, eight fresh cadaver normal lunates were scanned with micro-computed tomography. High-resolution images of the micro-structure of normal lunates were obtained and we analyzed the nutrient foramina. Then nine regions of interest(ROI) were chosen in the central sagittal plane so that we could obtain the parameters of trabecular bones of ROIs. The distal lamellar-like compact structure had statistically significant differences when it was compared with the ROIs in the volar and dorsal ends of the distal cortex. The difference of diameter between the volar and dorsal foramina was significant(P<0.05). However, there was no significant difference regarding the number. The trabecular bones of the volar and dorsal distal ends had lower intensity than those of the distal central subchondral bone plate. The diameters of the nutrient foramina on the volar cortex were larger than those on the dorsal. This research provided more detailed information about microstructure of normal lunate and the nutrient foramina on cortex, and a reference for further study about diseased lunate. 展开更多
关键词 normal lunate trabecular bones micro-computed tomography nutrient foramina
暂未订购
Monitoring vascular changes induced by photodynamic therapy using contrast-enhanced micro-computed tomography
8
作者 Otilia C. Nasui Stuart K. Bisland Nancy L. Ford 《Journal of Biomedical Science and Engineering》 2013年第2期124-133,共10页
The aim of this study was to determine whether contrast-enhanced micro-computed tomography can be used for non-invasive imaging of the early-stage changes in the vasculature of tumours that have been treated with phot... The aim of this study was to determine whether contrast-enhanced micro-computed tomography can be used for non-invasive imaging of the early-stage changes in the vasculature of tumours that have been treated with photodynamic therapy (PDT). The subjects used were C3H mice with an RIF-1 tumour implanted subcutaneously and allowed to grow for 3 weeks prior to treatment. The experimental groups were PDT-treated (150 J/cm2 and 50 J/cm2) and control (150 J/cm2 light-only and untreated). The laser light exposure was performed at 15 - 30 minutes after the administration of the photosensitizer (BPD-MA). The contrast-enhanced micro-computed tomography imaging procedure consisted of eight-second scans taking place before treatment and up to 24 hours after treatment. The 150 J/cm2 PDT group showed a significant increase in the ratio of blood volume to tumour volume at 2, 8 and 24 hours after treatment when compared to pre-treatment measurements (p 2 PDT group at 24 hours after treatment. This preliminary study indicates that micro-CT can detect compromised vasculature in tumours treated with high-fluence photodynamic therapy as early as 2 hours post treatment. 展开更多
关键词 micro-computed TOMOGRAPHY CONTRAST AGENT ANIMAL Model Photodynamic THERAPY Cancer
暂未订购
Micro-computed tomography assessment of human femoral trabecular bone for two disease groups(fragility fracture and coxarthrosis):Age and gender related effects on the microstructure
9
作者 Ana Catarina Vale Manuel F.C.Pereira +7 位作者 Antonio Maurício Bruno Vidal Ana Rodrigues Joana Caetano-Lopes Ara Nazarian Joao E.Fonseca Helena Canhao Maria Fatima Vaz 《Journal of Biomedical Science and Engineering》 2013年第2期175-184,共10页
The aim of this study was to identify three-dimensional microstructural changes of trabecular bone with age and gender, using micro-computed tomography. Human trabecular bone from two disease groups, osteoporosis and ... The aim of this study was to identify three-dimensional microstructural changes of trabecular bone with age and gender, using micro-computed tomography. Human trabecular bone from two disease groups, osteoporosis and osteoarthritis was analyzed. A prior analysis of the effects of some procedure variables on the micro-CT results was performed. Preliminary micro-CT scans were performed with three voxel resolutions and two acquisition conditions. On the reconstruction step, the image segmentation was performed with three different threshold values. Samples were collected from patients, with coxarthrosis (osteoarthritis) or fragility fracture (osteoporosis). The specimens of the coxarthrosis group include twenty females and fifteen males, while the fragility fracture group was composed by twenty three females and seven males. The mean age of the population was 69 ± 11 (females) and 67 ± 10 years (males), in the coxarthrosis group, while in the fragility fracture group was 81 ± 6 (females) and 78 ± 6 (males) years. The 30 μm voxel size provided lower percentage difference for the microarchitecture parameters. Acquisition conditions with 160 μA and 60 kV permit the evaluation of all the volume’s sample, with low average values of the coefficients of variation of the microstructural parameters. No statistically significant differences were found between the two diseases groups, neither between genders. However, with aging, there is a decrease of bone volume fraction, trabecular number and fractal dimension, and an increase of structural model index and trabecular separation, for both disease groups and genders. The parameters bone specific surface, trabecular thickness and degree of anisotropy have different behaviors with age, depending on the type of disease. While in coxarthrosis patients, trabecular thickness increases with age, in the fragility fracture group, there is a decrease of trabecular thickness with increasing age. Our findings indicate that disease, age and gender do not provide significant differences in trabecular microstructure. With aging, some parameters exhibit different trends which are possibly related to different mechanisms for different diseases. 展开更多
关键词 Trabecular Bone micro-computed Tomography Coxarthrosis Fragility Fracture Age GENDER
暂未订购
Structural analysis on cutting notch of tea stalk by X-ray micro-computed tomography 被引量:1
10
作者 Zhe Du Yongguang Hu +2 位作者 Wenye Wu Yongzong Lu Noman Ali Buttar 《Information Processing in Agriculture》 EI 2020年第2期242-248,共7页
Quantitative analysis on cutting notch of tea stalk is one method to better understand shear resistance and mechanical properties of the stalk,which could improve cutting performance and efficiency for tea harvesting.... Quantitative analysis on cutting notch of tea stalk is one method to better understand shear resistance and mechanical properties of the stalk,which could improve cutting performance and efficiency for tea harvesting.Optimal design of the cutter might be achieved through structural analysis of cutting notch by X-ray micro-computed tomography(micro-CT).The third inter-node of the stalks were sampled and scanned by micro-CT after they were cut at different cutting depths(0.7,1.5,2.3 mm)and cutting edge angles of cutter(30,35,40).The structural change of the cutting notch and cutting force was observed.Grey-scale histogram analysis and bimodal segmentation method were used to extract the information about cutting notch from 2D slice images.A 3D model of the stalk was established with reconstruction and volume rendering.Besides,maximum crosssectional area ratio of cutting notch(MCSARCN)and volume ratio of cutting notch(VRCN)were calculated.The results show that MCSARCN and VRCN had a closely relationship with the cutting force,cutting depth and cutting edge angle according to 3D tomographic images and 2D slice images.Both MCSARCN and VRCN increased with cutting depth,despite of cutting edge angle.For cutting edge angle of 30,35and 40at different cutting depths,MCSARCN increased from 4.89%to 9.47%,from 8.51%to 22.83%and from 4.30%to 16.87%,respectively.Meanwhile,VRCN increased from 1.59%to 2.13%,from 2.98%to 5.76%and from 3.04%to 5.01%,respectively.When cutting depth was 1.5 mm,cutting force increased but VRCN present a decreased trend with cutting edge angle.X-ray micro-CT could be used to analyze the structure on cutting notch of tea stalks which is helpful in optimizing the structural parameters of the cutter. 展开更多
关键词 Tea stalk Cutting notch X-ray micro-computed tomography Structural analysis
原文传递
Anti-catabolic effect of caffeic acid phenethyl ester, an active component of honeybee propolis on bone loss in ovariectomized mice: a micro-computed tomography study and histological analysis
11
作者 Duan Wangping Wang Qing +5 位作者 Li Fang Xiang Chuan Zhou Lin Xu Jiake Feng Haotian Wei Xiaochun 《Chinese Medical Journal》 SCIE CAS CSCD 2014年第22期3932-3936,共5页
Background Osteoporosis (OP) is a common bone disease,which adversely affects life quality.Effective treatments are necessary to combat both the loss and fracture of bone.Recent studies indicated that caffeic acid p... Background Osteoporosis (OP) is a common bone disease,which adversely affects life quality.Effective treatments are necessary to combat both the loss and fracture of bone.Recent studies indicated that caffeic acid phenethyl ester (CAPE) is a natural chemical compound from honeybee propolis which is capable of attenuating osteoclastogenesis and bone resorption.Therefore,this study aimed to investigate the effect of CAPE on bone loss in OP mice using micro-computed tomography (CT) and histology.Methods Eighteen mice were prepared and evenly divided into three groups.The six mice in the sham+PBS group did not undergo ovariectomy and were intraperitoneally injected with PBS during the curing period.Twelve mice were ovariectomized (OVX) to induce OP.Six of them in the OVX+CAPE group were intraperitoneally injected with 0.5 mg/kg CAPE twice per week for 4 weeks after ovariectomy.The other six OVX mice in OVX+PBS group were treated with PBS.All the mice were sacrificed 4 weeks after ovariectomy.The tibias were bilaterally excised for micro-CT scan and histological analysis.The Mann-Whitney U test was used to test the statistical differences among groups.Results Bone loss occurred in OVX mice.Compared with the sham+PBS group,mice in the OVX+PBS group exhibited a significant decrease in bone mineral density (BMD,P <0.05),bone volume fraction (BV/TV,P <0.01),trabecular thickness (Tb.Th,P <0.05),and trabecular number (Tb.N,P <0.01),as well as a non-insignificant increase in the number of osteoclasts (N.Oc/B.Pm).With CAPE treatment,the microarchitecture of the tibial metaphyses was significantly improved with a reduction of osteoclast formation.Compared with the OVX+PBS group,BV/TV in the OVX+CAPE group was significantly increased by 33.9% (P <0.05).Conclusion CAPE therapy results in the protection of bone loss induced by OVX. 展开更多
关键词 caffeic acid phenethyl ester OSTEOPOROSIS bone loss micro-computed tomography
原文传递
Bilateral asymmetry in craniofacial structures and kinematics of feeding attacks in the scale-eating cichlid fish, Perissodus microlepis
12
作者 Xiaomeng Tian Sooyeon Lee +1 位作者 Jan Tuckermann Axel Meyer 《Zoological Research》 2025年第2期370-378,共9页
Cichlid fishes are a textbook example for adaptive radiations,since they diversified into several hundred highly specialized species in each of three great East African lakes.Even scale-eating,an extremely specialized... Cichlid fishes are a textbook example for adaptive radiations,since they diversified into several hundred highly specialized species in each of three great East African lakes.Even scale-eating,an extremely specialized feeding mode,evolved independently multiple times in these radiations and in Lake Tanganyika alone,six endemic scale-eating species occupy this extremely specialized ecological niche.Perissodus microlepis went a step further,by evolving bilaterally asymmetrical heads with an intra-specific polymorphism where left-and right-headed morphs predominantly scrape scales from the opposite sides of their prey.While the bilateral asymmetry of scale-eating cichlids has been known,exactly which craniofacial features explain the laterality of the heads remained unclear.Here we aimed,by utilizing micro-computed tomography(μCT),to resolve this issue of how bilateral symmetry in the skeletal structure is broken in scale-eating Perissodus.Our 3D geometric morphometrics analysis clearly separated and identified the two groups of either left-or right-headed fish.In addition,we observed consistent asymmetric volume changes in the premaxilla,maxilla,and mandible of the craniofacial structures,where left-headed fish have larger jaw elements on the right side,and vice versa.The bimodality implies that the effect sizes of environmental factors might be minor while genetics might be responsible to a larger extent for the asymmetry observed in their head morphology.High-speed video analyses of attacks by asymmetrical morphotypes revealed that they utilize their asymmetrical mouth protrusion,as well as lateralized behavior,to re-orientate the gape towards the preferred side of their prey fish to more efficiently scrape scales. 展开更多
关键词 CICHLIDS Geometric morphology Asymmetry micro-computed tomography
在线阅读 下载PDF
The enhancements of pore morphology and size distribution by straw return are mediated by increases in aggregate-associated carbon and nitrogen
13
作者 Ying Zhao Xiaozeng Han +4 位作者 Chen Qiu Wenxiu Zou Xinchun Lu Jun Yan Xu Chen 《Journal of Integrative Agriculture》 2025年第4期1562-1576,共15页
The accumulation of soil organic carbon(SOC)and total nitrogen(TN)is easily accomplished by returning crop straw,which strongly affects the formation and pore structure of aggregates,especially in black soil.We return... The accumulation of soil organic carbon(SOC)and total nitrogen(TN)is easily accomplished by returning crop straw,which strongly affects the formation and pore structure of aggregates,especially in black soil.We returned maize straw at different rates(6,000,9,000,12,000 and 15,000 kg ha^(-1))for nine years to investigate its influence on the SOC and TN contents in the SOC fractions of aggregates by combining size and density fractionation.Their subsequent influences on pore morphology and size distribution characteristics were examined using X-ray microcomputed tomography scanning(μCT).The results showed that returning straw significantly increased the contents of C and N in the SOC fractions of aggregates,especially at the return rates of 12,000 and 15,000 kg ha^(-1),which in turn promoted aggregate formation and stability,and ultimately amended pore structure.The pore size>100μm,porosity(>2μm),and morphological characteristics(anisotropy,circularity,connectivity and fractal dimension)significantly increased,but the total number of pores significantly decreased(P<0.05).Our results indicated that the amendment of the pore morphology and size distribution of soil aggregates was primarily controlled by the higher contents of C and N in the density fractions of aggregates,rather than in the aggregate sizes.Furthermore,this pore network reconfiguration favored the storage of C and N simultaneously.The findings of this study offer valuable new insights into the relationships between C and N storage and the pore characteristics in soil aggregates under straw return. 展开更多
关键词 aggregate pore structure black soil density fractions water-stable aggregates X-ray micro-computed tomography
在线阅读 下载PDF
Pore structure variation characteristics of a Chinese local mudstone before and after the first cycle of wetting and drying
14
作者 ZHANG Qing-song LIU Zhi-bin +3 位作者 TANG Ya-sen DENG Yong-feng LUO Ting-yi MENG Fan-xing 《Journal of Central South University》 2025年第2期582-596,共15页
As a typical sedimentary soft rock,mudstone has the characteristics of being easily softened and disintegrated under the effect of wetting and drying(WD).The first cycle of WD plays an important role in the entire WD ... As a typical sedimentary soft rock,mudstone has the characteristics of being easily softened and disintegrated under the effect of wetting and drying(WD).The first cycle of WD plays an important role in the entire WD cycles.X-ray micro-computed tomography(micro-CT)was used as a non-destructive tool to quantitatively analyze microstructural changes of the mudstone due to the first cycle of WD.The test results show that WD leads to an increase of pore volume and pore connectivity in the mudstone.The porosity and fractal dimension of each slice of mudstone not only increase in value,but also in fluctuation amplitude.The pattern of variation in the frequency distribution of the equivalent radii of connected,isolated pores and pore throats in mudstone under WD effect satisfies the Gaussian distribution.Under the effect of WD,pores and pore throats with relatively small sizes increase the most.The sphericity of the pores in mudstones is positively correlated with the pore radius.The WD effect transforms the originally angular and flat pores into round and regular pores.This paper can provide a reference for the study of the deterioration and catastrophic mechanisms of mudstone under wetting and drying cycles. 展开更多
关键词 MUDSTONE wetting and drying cycle X-ray micro-computed tomography pore structure pore morphology
在线阅读 下载PDF
Microscopic analysis of mechanical anisotropy and damage evolution of 3D printed rock-like samples under uniaxial compressive tests
15
作者 Yulong Shao Jingwei Yang +3 位作者 Jineon Kim Jae-Joon Song Juhyuk Moon Jianyong Han 《Journal of Rock Mechanics and Geotechnical Engineering》 2025年第2期688-704,共17页
Three-dimensional printing(3DP)offers valuable insight into the characterization of natural rocks and the verification of theoretical models due to its high reproducibility and accurate replication of complex defects ... Three-dimensional printing(3DP)offers valuable insight into the characterization of natural rocks and the verification of theoretical models due to its high reproducibility and accurate replication of complex defects such as cracks and pores.In this study,3DP gypsum samples with different printing directions were subjected to a series of uniaxial compression tests with in situ micro-computed tomography(micro-CT)scanning to quantitatively investigate their mechanical anisotropic properties and damage evolution characteristics.Based on the two-dimensional(2D)CT images obtained at different scanning steps,a novel void ratio variable was derived using the mean value and variance of CT intensity.Additionally,a constitutive model was formulated incorporating the proposed damage variable,utilizing the void ratio variable.The crack evolution and crack morphology of 3DP gypsum samples were obtained and analyzed using the 3D models reconstructed from the CT images.The results indicate that 3DP gypsum samples exhibit mechanical anisotropic characteristics similar to those found in naturally sedimentary rocks.The mechanical anisotropy is attributed to the bedding planes formed between adjacent layers and pillar-like structures along the printing direction formed by CaSO_(4)·2H_(2)O crystals of needle-like morphology.The mean gray intensity of the voids has a positive linear relationship with the threshold value,while the CT variance and void ratio have concave and convex relationships,respectively.The constitutive model can effectively match the stress–strain curves obtained from uniaxial compression experiments.This study provides comprehensive explanations of the failure modes and anisotropic mechanisms of 3DP gypsum samples,which is important for characterizing and understanding the failure mechanism and microstructural evolution of 3DP rocks when modeling natural rock behavior. 展开更多
关键词 Quantitative analysis Three-dimensional printing(3DP) Gypsum samples In situ micro-computed tomography(micro-CT)scanning Mechanical anisotropy Bedding planes Damage evolution
在线阅读 下载PDF
Intravascular ULTRA sound-guided percutaneous coronary intervention in patients with STEMI: Rationale and design of the ULTRA-STEMI trial
16
作者 Efstratios Karagiannidis Andreas S Papazoglou +8 位作者 Athanasios Samaras Athina Nasoufidou Georgios Zormpas Georgios Tagarakis Konstantinos C Theodoropoulos Marios Papadakis Apostolos Tzikas Nikolaos Fragakis George Kassimis 《World Journal of Cardiology》 2025年第4期93-103,共11页
BACKGROUND Safety and efficacy of intravascular ultrasound(IVUS)guidance in percutaneous coronary intervention(PCI)has been consistently shown in recent trials.However,prospective data on the clinical effects of IVUS ... BACKGROUND Safety and efficacy of intravascular ultrasound(IVUS)guidance in percutaneous coronary intervention(PCI)has been consistently shown in recent trials.However,prospective data on the clinical effects of IVUS usage in primary PCI are still warranted.The ULTRA-STEMI trial is a prospective investigator-initiated observational single-center cohort trial aiming to enroll 80 patients with STEMI.AIM To investigate the outcomes of patients with STEMI undergoing IVUS-guided PCI and correlate derived IVUS measurements with clinical,procedural,imaging and follow-up outcomes of interest.METHODS Study participants will undergo primary PCI as per standardized procedures.IVUS pullbacks will be performed pre-intervention,post-lesion preparation,postintervention and post-optimization using a 20 MHz digital IVUS(Eagle Eye Platinum,Philips).Manual thrombus aspiration will be performed in cases of high thrombus burden.The aspirated thrombi will be scanned with micro-computed tomography to extract volumetric measurements of the aspirated thrombotic burden.Moreover,angiographic,peri-procedural and 3-year follow-up data will be gathered.Co-primary endpoints will be cardiovascular mortality and target vessel failure,defined as the composite of:Cardiovascular mortality,target vessel myocardial infarction and/or clinically driven target vessel revascularization.RESULTS The results of the study are expected by the third quarter of 2029.CONCLUSION The ULTRA-STEMI trial will add to the existing literature the clinical,angiographic,micro-computed tomography and follow-up outcomes of IVUS-guided PCI in 80 patients presenting with STEMI. 展开更多
关键词 STEMI Primary percutaneous coronary intervention Intravascular ultrasound micro-computed tomography
暂未订购
Low-fat microwaved peanut snacks production:Effect of defatting treatment on structural characteristics,texture,color,and nutrition 被引量:2
17
作者 Bo Jiao Xin Guo +6 位作者 Yiying Chen Shah Faisal Wenchao Liu Xiaojie Ma Bicong Wu Guangyue Ren Qiang Wang 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2024年第7期2491-2502,共12页
This study develops low-fat microwaved peanut snacks(LMPS)using partially defatted peanuts(PDP)with different defatting ratios,catering to people’s pursuit of healthy,low-fat cuisine.The effects of defatting treatmen... This study develops low-fat microwaved peanut snacks(LMPS)using partially defatted peanuts(PDP)with different defatting ratios,catering to people’s pursuit of healthy,low-fat cuisine.The effects of defatting treatment on the structural characteristics,texture,color,and nutrient composition of LMPS were comprehensively explored.The structural characteristics of LMPS were characterized using X-ray micro-computed tomography(Micro-CT)and scanning electron microscope(SEM).The results demonstrated that the porosity,pore number,pore volume,brightness,brittleness,protein content,and total sugar content of LMPS all significantly increased(P<0.05)with the increase in the defatting ratio.At the micro level,porous structure,cell wall rupture,and loss of intracellular material could be observed in LMPS after defatting treatments.LMPS made from PDP with a defatting ratio of 64.44%had the highest internal pore structural parameters(porosity 59%,pore number 85.3×10^(5),pore volume 68.23 mm3),the brightest color(L^(*) 78.39±0.39),the best brittleness(3.64±0.21)mm^(–1)),and the best nutrition(high protein content,(34.02±0.38)%;high total sugar content,(17.45±0.59)%;low-fat content,(27.58±0.85)%).The study provides a theoretical basis for the quality improvement of LMPS. 展开更多
关键词 low-fat microwaved peanut snacks(LMPS) X-ray micro-computed tomography(Micro-CT) porosity TEXTURE COLOR NUTRITION
在线阅读 下载PDF
Phase behavior of gas condensate in porous media using real-time computed tomography scanning 被引量:2
18
作者 Wen-Long Jing Lei Zhang +5 位作者 Ai-Fen Li Jun-Jie Zhong Hai Sun Yong-Fei Yang Yu-Long Cheng Jun Yao 《Petroleum Science》 SCIE EI CAS CSCD 2024年第2期1032-1043,共12页
The phase behavior of gas condensate in reservoir formations differs from that in pressure-volume-temperature(PVT)cells because it is influenced by porous media in the reservoir formations.Sandstone was used as a samp... The phase behavior of gas condensate in reservoir formations differs from that in pressure-volume-temperature(PVT)cells because it is influenced by porous media in the reservoir formations.Sandstone was used as a sample to investigate the influence of porous media on the phase behavior of the gas condensate.The pore structure was first analyzed using computed tomography(CT)scanning,digital core technology,and a pore network model.The sandstone core sample was then saturated with gas condensate for the pressure depletion experiment.After each pressure-depletion state was stable,realtime CT scanning was performed on the sample.The scanning results of the sample were reconstructed into three-dimensional grayscale images,and the gas condensate and condensate liquid were segmented based on gray value discrepancy to dynamically characterize the phase behavior of the gas condensate in porous media.Pore network models of the condensate liquid ganglia under different pressures were built to calculate the characteristic parameters,including the average radius,coordination number,and tortuosity,and to analyze the changing mechanism caused by the phase behavior change of the gas condensate.Four types of condensate liquid(clustered,branched,membranous,and droplet ganglia)were then classified by shape factor and Euler number to investigate their morphological changes dynamically and elaborately.The results show that the dew point pressure of the gas condensate in porous media is 12.7 MPa,which is 0.7 MPa higher than 12.0 MPa in PVT cells.The average radius,volume,and coordination number of the condensate liquid ganglia increased when the system pressure was between the dew point pressure(12.7 MPa)and the pressure for the maximum liquid dropout,Pmax(10.0 MPa),and decreased when it was below Pmax.The volume proportion of clustered ganglia was the highest,followed by branched,membranous,and droplet ganglia.This study provides crucial experimental evidence for the phase behavior changing process of gas condensate in porous media during the depletion production of gas condensate reservoirs. 展开更多
关键词 Gas condensate Pressure depletion Real-time micro-computed tomography scanning Distribution of condensate liquid
原文传递
In-situ Micro-CT analysis of deformation behavior in sandwich-structured meta-stable beta Ti−35Nb alloy
19
作者 Yu-jing LIU Zi-lin ZHANG +4 位作者 Jin-cheng WANG Xiang WU Xiao-chun LIU Wei-ying HUANG Lai-chang ZHANG 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2024年第8期2552-2562,共11页
Beta Ti−35Nb sandwich-structured composites with various reinforcing layers were designed and produced using additive manufacturing(AM)to achieve a balance between light weight and high strength.The impact of reinforc... Beta Ti−35Nb sandwich-structured composites with various reinforcing layers were designed and produced using additive manufacturing(AM)to achieve a balance between light weight and high strength.The impact of reinforcing layers on the compressive deformation behavior of porous composites was investigated through micro-computed tomography(Micro-CT)and finite element method(FEM)analyses.The results indicate that the addition of reinforcement layers to sandwich structures can significantly enhance the compressive yield strength and energy absorption capacity of porous metal structures;Micro-CT in-situ observation shows that the strain of the porous structure without the reinforcing layer is concentrated in the middle region,while the strain of the porous structure with the reinforcing layer is uniformly distributed;FEM analysis reveals that the reinforcing layers can alter stress distribution and reduce stress concentration,thereby promoting uniform deformation of the porous structure.The addition of reinforcing layer increases the compressive yield strength of sandwich-structured composite materials by 124%under the condition of limited reduction of porosity,and the yield strength increases from 4.6 to 10.3 MPa. 展开更多
关键词 beta titanium alloy sandwich-structured composite in-situ micro-computed tomography finite element modeling compressive behavior
在线阅读 下载PDF
Controlled coupling and characterization of oyster (Crassostrea gigas) ferritin with gold nanostars
20
作者 Han Li Xiaoyu Xia +4 位作者 Shuzhen Cheng Jiachen Zang Zhenyu Wang Xianbing Xu Ming Du 《Food Science and Human Wellness》 SCIE CAS CSCD 2024年第6期3202-3209,共8页
Ferritin has good thermal stability,resistance to certain acids and bases,and targeting,and has broad application prospects in the synthesis of gold nanostars(AuNS).In this study,we screened monodisperse AuNS with uni... Ferritin has good thermal stability,resistance to certain acids and bases,and targeting,and has broad application prospects in the synthesis of gold nanostars(AuNS).In this study,we screened monodisperse AuNS with uniform particle size and morphology through a one-step synthesis method and coupled the synthesized AuNS with oyster ferritin(GF1).The results showed that the surface plasmon resonance(SPR)peaks of the coupled GF1@AuNS changed signifi cantly,and the changes in infrared spectra and potential confirmed the success of the synthesis,while the microscopic morphology showed an increase in particle size and surface peak coverage.Furthermore,GF1@AuNS does not induce cell death in the 100µmol/L range,is highly stable in physiological environments,and exhibits good X-ray attenuation in micro-computed tomography.Due to the unique functional activity of ferritin and AuNS,GF1@AuNS has potential applications in food detection and drug development in the future. 展开更多
关键词 Gold nanostars(AuNS) Oyster ferritin Synthesis Structure micro-computed tomography
在线阅读 下载PDF
上一页 1 2 3 下一页 到第
使用帮助 返回顶部