期刊文献+
任意字段
题名或关键词
题名
关键词
摘要
作者
第一作者
机构
刊名
分类号
参考文献
作者简介
基金资助
栏目信息
共找到345篇文章
< 1 2 … 18 >
每页显示 20 50 100
已选0条
引用分析
参考文献
引证文献
 统计分析
检索结果
已选文献
显示方式：
Role of diffusion-weighted magnetic resonance imaging and apparent diffusion coefficient in subtyping renal cell carcinoma 认领 引用
1
作者 Hira Lal Pinky Jowel +9 位作者 Pragati Verma Athar Shamim Raghunandan Prasad Anuradha Singh Uday P Singh Sanjoy K Sureka Farhana Siddiqui Manoj Jain Aneesh Srivastava Priyank Yadav 《World Journal of Radiology》 2026年第5期67-76,共10页
BACKGROUND Diffusion-weighted magnetic resonance imaging(DWI)has emerged as a noncontrast functional imaging technique for renal mass characterization.Its role in differentiating histopathological subtypes of renal ce... BACKGROUND Diffusion-weighted magnetic resonance imaging(DWI)has emerged as a noncontrast functional imaging technique for renal mass characterization.Its role in differentiating histopathological subtypes of renal cell carcinoma(RCC)remains an area of active investigation.AIM To evaluate the role of DWI and apparent diffusion coefficient(ADC)values in differentiating histopathological subtypes of RCC.METHODS In this prospective observational study,127 patients with histopathologically proven RCC who underwent preoperative magnetic resonance imaging(MRI)including DWI were analyzed.Diffusion-weighted imaging was performed using b values of 0 second/mm2 and 1000 seconds/mm2,and ADC maps were generated.ADC values were measured from solid tumor components and compared among RCC subtypes.Statistical analysis included subgroup comparisons and receiver operating characteristic curve analysis to assess the ability of ADC values to differentiate clear cell RCC(ccRCC)from non-ccRCC.RESULTS Of the 127 RCCs,97(76.4%)were ccRCC,24(18.9%)papillary RCC,and 6(4.7%)chromophobe RCC.The mean ADC value of ccRCC[(1.391±0.271)×10-3mm2/second]was significantly higher than that of papillary RCC[(0.876±0.293)×10-3mm2/second;P<0.001]and chromophobe RCC[(1.059±0.369)×10-3mm2/second;P=0.04].No significant difference was observed between papillary and chromophobe RCC(P=0.396).When grouped,ccRCC demonstrated a significantly higher mean ADC value compared with non-ccRCC[(1.391±0.271)×10-3mm2/second vs(0.915±0.312)×10-3mm2/second;P<0.001].Receiver operating characteristic analysis yielded an area under the curve of 0.889(95%confidence interval:0.804-0.975).An ADC threshold of 1.08×10-3mm2/second achieved 90%sensitivity and 83%specificity for identifying ccRCC.CONCLUSION DWI with quantitative ADC analysis reliably differentiates clear cell from non-ccRCC and demonstrates significant correlation with RCC subtype and tumor grade.DWI serves as a valuable adjunct to conventional MRI,particularly in patients with contraindications to contrast administration. 展开更多
关键词 Renal cell carcinoma Diffusion-weighted imaging Apparent diffusion coefficient Magnetic resonance imaging Tumor subtyping
暂未订购 下载PDF
Apparent diffusion coefficient of kidneys with non-contrast magnetic resonance angiography for functional and anatomical assessment in renal artery stenosis 认领 引用
2
作者 Hira Lal Surabhi Agarwal +7 位作者 Kaushik Ponmalai Raghunandan Prasad Dharmendra S Bhadauria Sanjay Gambhir Swagata Mandal Sandeep Kumar Priyank Yadav Pinky Jowel 《World Journal of Methodology》 2026年第1期198-210,共13页
BACKGROUND Renal artery stenosis(RAS)is a vascular disorder linked to secondary hypertension,chronic kidney disease,and renal failure due to interstitial fibrosis.Early diagnosis is crucial as RAS-induced hypertension... BACKGROUND Renal artery stenosis(RAS)is a vascular disorder linked to secondary hypertension,chronic kidney disease,and renal failure due to interstitial fibrosis.Early diagnosis is crucial as RAS-induced hypertension responds well to angioplasty.Non-invasive imaging techniques,including non-contrast magnetic resonance angiography(NC-MRA),help assess RAS without contrast-related risks.Diffusion-weighted MR imaging(DW-MRI)has emerged as a promising method for evaluating kidney function by measuring the apparent diffusion coefficient(ADC),which correlates with renal pathology.AIM To compare ADC values in hypertensive,RAS,and healthy kidneys,assess the correlation between ADC and stenosis severity,and evaluate its relationship with split glomerular filtration rate(GFR).METHODS This prospective observational study which included 86 patients with suspected RAS and twenty normal healthy controls underwent NC-MRA on a 3T-MR-Scanner followed by DW-MRI at b values of 0 and 1000 seconds/mm2 in the transverse plane.ADC maps were created using Functool.ADC values were measured in the cortex and medulla of each kidney's upper,middle,and lower pole,and the average ADC(ADCavg)for cortex and medulla calculated.In patients with RAS,degree of stenosis(DOS)was calculated on NC-MRA.The ADC of 212 kidneys was compared,and the relationship between DOS and ADC was established.In addition,split GFR was calculated in 30 kidneys using 99mTc-DTPA,and correlated with ADC value.The ADC values of kidneys with and without RAS were compared using the Student’s t-test.The correlation between ADC and stenosis severity was assessed by Spearman’s test,while the relationship between ADC and split GFR was evaluated using Pearson’s test.A P value<0.05 was considered statistically significant.RESULTS RAS was detected in 58 of 86(67.44%)hypertensive patients(81 of 172 kidneys),and the ADCavg(P=0.044)was significantly lower in RAS kidneys than in kidneys with normal arteries and essential hypertension and healthy controls.CONCLUSION DW-MRI can be a useful non-invasive technique to estimate the kidney’s functional status in RAS patients.It can be used as a complementary assessment tool with NC-MRA to triage patients in need of interventional management. 展开更多
关键词 Renal artery stenosis Diffusion weighted imaging Apparent diffusion coefficient Magnetic resonance imaging Non-contrast renal magnetic resonance angiography Hypertension
暂未订购 下载PDF
Time-dependent Diffusion Coefficient and Conventional Diffusion Constant of Nanoparticles in Polymer Melts by Mode-coupling Theory 认领 引用 被引量：2
3
作者 赖鑫昱 赵南蓉 《Chinese Journal of Chemical Physics》 SCIE EI CAS CSCD 2013年第2期163-171,I0003,共9页
Time-dependent diffusion coefficient and conventional diffusion constant are calculated and analyzed to study diffusion of nanoparticles in polymer melts. A generalized Langevin equa- tion is adopted to describe the d... Time-dependent diffusion coefficient and conventional diffusion constant are calculated and analyzed to study diffusion of nanoparticles in polymer melts. A generalized Langevin equa- tion is adopted to describe the diffusion dynamics. Mode-coupling theory is employed to calculate the memory kernel of friction. For simplicity, only microscopic terms arising from binary collision and coupling to the solvent density fluctuation are included in the formalism. The equilibrium structural information functions of the polymer nanocomposites required by mode-coupling theory are calculated on the basis of polymer reference interaction site model with Percus-Yevick closure. The effect of nanoparticle size and that of the polymer size are clarified explicitly. The structural functions, the friction kernel, as well as the diffusion coefficient show a rich variety with varying nanoparticle radius and polymer chain length. We find that for small nanoparticles or short chain polymers, the characteristic short time non-Markov diffusion dynamics becomes more prominent, and the diffusion coefficient takes longer time to approach asymptotically the conventional diffusion constant. This constant due to the microscopic contributions will decrease with the increase of nanoparticle size, while increase with polymer size. Furthermore, our result of diffusion constant from mode- coupling theory is compared with the value predicted from the Stokes-Einstein relation. It shows that the microscopic contributions to the diffusion constant are dominant for small nanoparticles or long chain polymers. Inversely, when nanonparticle is big, or polymer chain is short, the hydrodynamic contribution might play a significant role. 展开更多
关键词 Time-dependent diffusion coefficient Conventional diffusion coefficient Poly-mer melts Mode-coupling theory Polymer reference interaction site model
暂未订购 下载PDF
Apparent diffusion coefficient by diffusion-weighted magnetic resonance imaging as a sole biomarker for staging and prognosis of gastric cancer 认领 引用 被引量：16
4
作者 Francesco Giganti Alessandro Ambrosi +7 位作者 Damiano Chiari Elena Orsenigo Antonio Esposito Elena Mazza Luca Albarello Carlo Staudacher Alessandro Del Maschio Francesco De Cobelli 《Chinese Journal of Cancer Research》 SCIE CAS CSCD 2017年第2期118-126,共9页
Objective： To investigate the role of apparent diffusion coefficient （ADC） from diffusion-weighted magnetic resonance imaging （DW-MRI） when applied to the 7th TNM classification in the staging and prognosis of ga... Objective： To investigate the role of apparent diffusion coefficient （ADC） from diffusion-weighted magnetic resonance imaging （DW-MRI） when applied to the 7th TNM classification in the staging and prognosis of gastric cancer （GC）. Methods： Between October 2009 and May 2014, a total of 89 patients with non-metastatic, biopsy proven GC underwent 1.5T DW-MRI, and then treated with radical surgery. Tumor ADC was measured retrospectively and compared with final histology following the 7th TNM staging （local invasion, nodal involvement and according to the different groups -- stage Ⅰ, Ⅱ and Ⅲ）. Kaplan-Meier curves were also generated. The follow-up period is updated to May 2016. Results： Median follow-up period was 33 months and 45/89 （51%） deaths from GC were observed. ADC was significantly different both for local invasion and nodal involvement （P〈0.001）. Considering final histology as the reference standard, a preoperative ADC cut-offof 1.80×10-3 mm^2/s could distinguish between stages I and Ⅱ and an ADC value of ≤1.36-10-3 mm^2/s was associated with stage Ⅲ（P〈0.001）. Kaplan-Meier curves demonstrated that the survival rates for the three prognostic groups were significantly different according to final histology and ADC cut-offs （P〈0.001）. Conclusions： ADC is different according to local invasion, nodal involvement and the 7th TNM stage groups for GC, representing a potential, additional prognostic biomarker. The addition of DW-MRI could aid in the staging and risk stratification of GC. 展开更多
关键词 Apparent diffusion coefficient diffusion-weighted magnetic resonance imaging gastric cancer prognosis TNM staging
暂未订购 下载PDF
Apparent diffusion coefficient values of normal testis and variations with age 认领 引用 被引量：8
5
作者 Athina C Tsili Dimitrios Giannakis +4 位作者 Anastasios Sylakos Alexandra Ntorkou Loukas G Astrakas Nikolaos Sofikitis Maria I Argyropoulou 《Asian Journal of Andrology》 SCIE CAS CSCD 2014年第3期493-497,共5页
The usefulness of diffusion-weighted magnetic resonance imaging （DWI） in the evaluation of scrotal pathology has recently been reported. A standard reference of normal testicular apparent diffusion coefficient （ADC... The usefulness of diffusion-weighted magnetic resonance imaging （DWI） in the evaluation of scrotal pathology has recently been reported. A standard reference of normal testicular apparent diffusion coefficient （ADC） values and their variations with age is necessary when interpreting normal testicular anatomy and pathology. We evaluated 147 normal testes using DWI, including 71 testes from 53 men aged 20-39years （group 1）, 67 testes from 42 men aged 40-69 years （group 2） and nine testes from six men older than 70years （group 3）. DWI was performed along the axial plane, using a single shot, multislice spin-echo planar diffusion pulse sequence and b-values of 0 and 900 s mm-2. The mean and standard deviation of the ADC values of normal testicular parenchyma were calculated for each age group separately. Analysis of variance （ANOVA） followed by post hoc analysis （Dunnett T3） was used for statistical purposes. The ADC values （x 10-3 mm2s-1） of normal testicular tissue were different among age groups （group 1：1.08 ± 0.13; group 2：1.15 ±0.15 and group 3：1.31± 0.22）. ANOVA revealed differences in mean ADC among age groups （F= 11.391, P〈 0.001）. Post hoc analysis showed differences between groups 1 and 2 （P= 0.008） and between groups 1 and 3 （P= 0.043）, but not between groups 2 and 3 （P= 0.197）. Our findings suggest that ADC values of normal testicular tissue increase with advancing age. 展开更多
关键词 age apparent diffusion coefficient （ADC） diffusion-weighted magnetic resonance imaging testis
暂未订购 下载PDF
Influence of Binder Composition and Concrete Pore Structure on Chloride Diffusion Coefficient in Concrete 认领 引用 被引量：15
6
作者 LI Pengping SU Dagen +1 位作者 WANG Shengnian FAN Zhihong 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2011年第1期160-164,共5页
The influence of binder composition and pore structure of concrete on chloride diffusion coefficient in concrete were investigated by the natural immersion test,MIP test,SEM and EDS test,respectively.The experimental ... The influence of binder composition and pore structure of concrete on chloride diffusion coefficient in concrete were investigated by the natural immersion test,MIP test,SEM and EDS test,respectively.The experimental results showed that the effect of binder composition on chloride diffusion coefficient was the comprehensive result of concrete pore structure and binder hydration products,and the porosity and pore size distribution were the main factors that influence the changes of diffusion coefficient.The chloride diffusion coefficient decreased with increasing the curing temperature and the relative humidity.The hydration degree were promoted by improving curing temperatures,and then the porosity of concrete decreased and the proportion of gel pore and transitional pore increased,respectively.But the water evaporation decreased with increasing the relative humidity and then decreased porosity and increased the proportion of gel pore and transitional pore.Additionally,The chloride diffusion coefficient of concrete got the lower value when the appropriate replacement of fly ash in the ranges of 10%-20%,when the double-adding fly ash and slag content was 50%.The porosity increased and the ratio of C/S in C-S-H decreased with further increasing the fly ash content,which led to increase the chloride diffusion coefficient in concrete. 展开更多
关键词 binder composition pore structure marine concrete chloride diffusion coefficient
暂未订购 下载PDF
Diffusion Coefficients of l-Lysine Hydrochloride and l-Arginine Hydrochloride in Their Aqueous Solutions at 25℃ 认领 引用 被引量：9
7
作者 马沛生 吴艳霞 +2 位作者 刘耘畦 夏淑倩 李淑芬 《Chinese Journal of Chemical Engineering》 SCIE EI CAS 2000年第2期146-153,共8页
The diffusion coefficients of l-lysine hydrochloride and I-arginine hydrochloride in their aqueous solutions at 25℃ were determined by the metallic diaphragm cell method which is characterized by accuracy, promptness... The diffusion coefficients of l-lysine hydrochloride and I-arginine hydrochloride in their aqueous solutions at 25℃ were determined by the metallic diaphragm cell method which is characterized by accuracy, promptness and convenience. Meanwhile, the densities and viscosities of the solutions were also determined. Based on all these data a semi-empirical model for correlating the diffusion coefficients of solid organic salts in their aqueous solutions at 25℃ was proposed. The fitting result of this model is comparatively satisfactory. Compared to a former model, Gordon Model, this model can avoid a number of difficulties and arduous work. 展开更多
关键词 lysine hydrochloride arginine hydrochloride diffusion coefficient metallic diaphragm cell method semi-empirical model
暂未订购 下载PDF
First principles calculations of alloying element diffusion coefficients in Ni using the five-frequency model 认领 引用 被引量：9
8
作者 吴琼 李树索 +1 位作者 马岳 宫声凯 《Chinese Physics B》 SCIE EI CAS CSCD 2012年第10期585-591,共7页
The diffusion coefficients of several alloying elements（Al,Mo,Co,Ta,Ru,W,Cr,Re） in Ni are directly calculated using the five-frequency model and the first principles density functional theory.The correlation factors... The diffusion coefficients of several alloying elements（Al,Mo,Co,Ta,Ru,W,Cr,Re） in Ni are directly calculated using the five-frequency model and the first principles density functional theory.The correlation factors provided by the five-frequency model are explicitly calculated.The calculated diffusion coefficients show their excellent agreement with the available experimental data.Both the diffusion pre-factor（D 0） and the activation energy（Q） of impurity diffusion are obtained.The diffusion coefficients above 700 K are sorted in the following order：DAl〉DCr〉DCo〉DTa〉DMo〉DRu〉DW〉D Re.It is found that there is a positive correlation between the atomic radius of the solute and the jump energy of Ni that results in the rotation of the solute-vacancy pair（E 1）.The value of E 2-E 1（E 2 is the solute diffusion energy） and the correlation factor each also show a positive correlation.The larger atoms in the same series have lower diffusion activation energies and faster diffusion coefficients. 展开更多
关键词 first-principles theory diffusion coefficients alloying element superalloy activation energy and diffusion pre-factor
暂未订购 下载PDF
Apparent diffusion coefficient in normal and abnormal pattern of intervertebral lumbar discs:initial experience 认领 引用 被引量：7
9
作者 Gang Niu Xuewen Yu +3 位作者 Jian Yang Rong Wang Shaojuan Zhang Youmin Guo 《Journal of Biomedical Research》 CAS 2011年第3期197-203,共7页
The aim of the present study was to compare the relationship of morphologically defined non-bulging/herni-ated,bulging and herniated intervertebral lumbar discs with quantitative apparent diffusion coefficient(ADC).Th... The aim of the present study was to compare the relationship of morphologically defined non-bulging/herni-ated,bulging and herniated intervertebral lumbar discs with quantitative apparent diffusion coefficient(ADC).Thirty-two healthy volunteers and 28 patients with back pain or sciatica were examined by MRI.All intervertebral lumbar discs from L1 to S1 were classified according to morphological abnormality and degenerated grades.The ADC values of nucleus pulposus(NP)were measured and recorded.The significant differences about mean ADC values of NP were found between non-bulging/herniated discs and bulging discs as well as herniated discs(P 0.05),whereas there were no significant differences in ADC values between bulging and herniated discs(P 0.05).Moreover,statistically significant relationship was found in the mean ADC values of NP between"non-bulging/herniated and non-degenerated discs"and"non-bulging/herniated degenerated discs"as well as herniated discs(P 0.05).Linear regression analysis between ADC value and disc level revealed an inverse correlation(r=-0.18).The ADC map of the NP is a potentially useful tool for the quantitative assessment of componential and molecular alterations accompanied with lumbar disc abnormalities. 展开更多
关键词 intervertebral lumbar disc apparent diffusion coefficient disc bulging disc herniation
暂未订购 下载PDF
A short review on diffusion coefficients in magnesium alloys and related applications 认领 引用 被引量：5
10
作者 Hui Shi Yuanding Huang +3 位作者 Qun Luo Sarkis Gavras Regine Willumeit-Römer Norbert Hort 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2022年第12期3289-3305,共17页
To have a better understand on the change of microstructure via kinetics, the diffusion behavior of Mg alloys is of special interest to researchers. Meanwhile, diffusion coefficients of Mg based alloys can explain and... To have a better understand on the change of microstructure via kinetics, the diffusion behavior of Mg alloys is of special interest to researchers. Meanwhile, diffusion coefficients of Mg based alloys can explain and represent their diffusion behavior well. The evolution of experimental and calculated methods for detecting and extracting diffusion coefficients was discussed briefly. The reasonable diffusion data, especially self-diffusion coefficients, impurity diffusion coefficients and inter-diffusion coefficients of Mg alloys, were reviewed in detail serving to design the Mg alloys with higher accuracy. Then the practical applications of diffusion coefficients of Mg alloys were summarized,including diffusional mobility establishing, precipitation simulation and mechanical properties prediction. 展开更多
关键词 Magnesium alloys Diffusion coefficients Atomic mobility Precipitation Mechanical properties
暂未订购 下载PDF
Investigations on structure and proton diffusion coefficient of rare earth ion (Y3+/Nd3+) and aluminum codoped α-Ni(OH)_2 认领 引用 被引量：7
11
作者 刘长久 宋莎 +1 位作者 李延伟 刘爱芳 《Journal of Rare Earths》 SCIE EI CAS 2008年第4期594-597,共4页
Rare earth ion （Nd^3＋/Y^3＋） and Al^3＋ codoped α-Ni（OH）2 powers were synthesized by chemical coprecipitation method. The structttre was analyzed with X-ray diffraction （XRD） and thermal gravity （TG）. Cyclic... Rare earth ion （Nd^3＋/Y^3＋） and Al^3＋ codoped α-Ni（OH）2 powers were synthesized by chemical coprecipitation method. The structttre was analyzed with X-ray diffraction （XRD） and thermal gravity （TG）. Cyclic voltammetry （CV） tests were performed to evaluate the proton diffusion coefficients of the samples. The results indicated that codoping of Y-Al and Nd-Al resulted in more water molecules contained within the crystal lattice and accordingly increased the interlayer spacing. In particular, the Y-Al codoped α-Ni（OH）2 showed a turbostratic structure. The calculated diffusion coefficients of the Y-Al codoped α-Ni（OH）2 and Nd-Al codoped α-Ni（OH）2 were 3.5×10^-10cm^2/s and 2.8× 10^-10 cm^2/s, respectively. 展开更多
关键词 α-nickel hydroxide chemical coprecipitation proton diffusion coefficient rare earths
暂未订购 下载PDF
Correlation of magnetic resonance imaging quantitative parameters and apparent diffusion coefficient value with pathological breast cancer 认领 引用 被引量：8
12
作者 Zhe Wang Guan-Ying Ren +1 位作者 Qian Yin Qian Wang 《World Journal of Clinical Cases》 SCIE 2022年第21期7333-7340,共8页
BACKGROUND China ranks 120th worldwide for the incidence of breast cancer and 163rd for mortality.Early screening,diagnosis,and timely determination of the optimal treatment plan can help ensure clinical efficacy and ... BACKGROUND China ranks 120th worldwide for the incidence of breast cancer and 163rd for mortality.Early screening,diagnosis,and timely determination of the optimal treatment plan can help ensure clinical efficacy and prognosis.AIM To investigate the relationship between quantitative magnetic resonance imaging parameters,apparent diffusion coefficient value,pathological immunohistochemical status,and patient prognosis.METHODS A total of 108 patients with breast cancer(breast cancer group)and 110 patients with benign breast tumors(benign group)confirmed by pathological examination at our Hospital from September 2013 to August 2016 were selected.All patients had undergone preoperative magnetic resonance imaging(MRI)examinations,and the quantitative parameters of MRI and apparent diffusion coefficient(ADC)values for the two groups were compared.The MRI quantitative parameters and ADC values of patients with different estrogen receptor(ER),progesterone receptor,and human epidermal growth factor receptor-2 expression were statistically analyzed.The relationship between the quantitative parameters of MRI and ADC values and patient recurrence was analyzed using receiver operating curves.RESULTS The measured values of the quantitative parameters of MRI-Ktrans,Kep,and Ve in the breast cancer group were higher than those in the benign group;the ADC value in the breast cancer group was lower than that in the benign group,and the difference was statistically significant(P<0.05).The Ktrans,Ve,and ADC values in patients with ER-positive breast cancer were significantly lower than those in patients with negative ER expression(P<0.05).After 5 years of follow-up,22 patients with breast cancer experienced postoperative recurrence.The Kep,Ve,and ADC values of the recurrence group were significantly lower than those of the non-recurrence group,and the difference was statistically significant(P<0.05).CONCLUSION MRI quantitative parameters and ADC are related to the expression of breast cancer-related immunological receptor factors and have certain clinical value in assessing postoperative recurrence in patients. 展开更多
关键词 Magnetic resonance Apparent diffusion coefficient Breast cancer Immunohistochemistry Prognosis
暂未订购 下载PDF
Early changes in apparent diffusion coefficient as an indicator of response to sorafenib in hepatocellular carcinoma 认领 引用 被引量：4
13
作者 Yi-lei ZHAO Qing-qu GUO +1 位作者 Gen-ren YANG Qi-dong WANG 《Journal of Zhejiang University-SCIENCE B》 SCIE CAS CSCD 2014年第8期713-719,共7页
Objective： The relationship between apparent diffusion coefficient （ADC） and chemotherapy has been established. However, whether ADC could be considered as a measure for monitoring response to sorafenib in hepatoce... Objective： The relationship between apparent diffusion coefficient （ADC） and chemotherapy has been established. However, whether ADC could be considered as a measure for monitoring response to sorafenib in hepatocellular carcinoma （HCC） has not been demonstrated. This study was to investigate the ADC changes of ad- vanced HCC under sorafenib treatment. Methods： Athymic mice with HepG2 xenografts were allocated to two groups： control and sorafenib （40 mg/kg, bid）. T2 and diffusion images were acquired at each time point （0, 10, 14, and 18 d post-therapy）. Tumor volume and changes in ADC were calculated. Results： Tumor volumes on Days 10, 14, and 18 after treatment showed significant decreases in the sorafenib-treated group compared with the control. Pretreatment ADC values were not significantly different between the control and treated groups. A slow increase in ADC in the peripheral zone of tumors appeared in the treated group, which was significantly higher compared with the control group on Days 10, 14, and 18. In the central part of tumors on Day 10 after treatment, an increase in ADC appeared in the treated and control groups, the ADC of the control group being significantly lower compared with the treated tumors From Day 10 to Day 14, the ADC map showed a progressive decrease in the central region of tumors in the treated and control groups. However, this change is more significant in the treated groups. Conclusions： Early changes in mean ADC correlated with sorafenib treatment in HCC, which are promising indicators for predicting sorafenib response in this carcinoma. 展开更多
关键词 Hepatocellular carcinoma Sorafenib Apparent diffusion coefficient Magnetic resonance imaging （MRI）
暂未订购 下载PDF
Effect of Rare Earths on Diffusion Coefficient and Transfer Coefficient of Carbon during Carburizing 认领 引用 被引量：12
14
作者 阎牧夫 刘志儒 《Journal of Rare Earths》 SCIE EI CAS 2001年第2期122-124,共3页
The diffusion coefficient of carbon in surface layer of steel-20 rare earth carburixed at 880 degreesC and 900 degreesC for 8 h was calculated by substituting the measured layer depths into the diffusion equation. The... The diffusion coefficient of carbon in surface layer of steel-20 rare earth carburixed at 880 degreesC and 900 degreesC for 8 h was calculated by substituting the measured layer depths into the diffusion equation. The mathematical model of the transfer coefficient of carbon was deduced based on the kinetics of weight gain during gas carburizing. The calculated results show that the main reason why the gas carburizing process is accelerated is due to the obvious increase in the diffusion coefficient and transfer coefficient of carbon resulted from the addition of RE. 展开更多
关键词 rare earths carburizing diffusion coefficient transfer coefficient
暂未订购 下载PDF
M-T Scheme for Predicting Effective Diffusion Coefficient of Chloride Ions in Cement-based Materials 认领 引用 被引量：2
15
作者 SUN Guowen ZHANG Jianjian +4 位作者 ZHANG Lijuan CAO Tongning WANG Penshuo ZHANG Ying YAN Na 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2020年第3期520-527,共8页
To investigate the transport characteristics of chloride ions in cement-based materials, the Mori-Tanaka (M-T) prediction scheme of the effective diffusion coefficient in composites containing single-phase and multi-p... To investigate the transport characteristics of chloride ions in cement-based materials, the Mori-Tanaka (M-T) prediction scheme of the effective diffusion coefficient in composites containing single-phase and multi-phase inclusions is systematically deduced based on the theory of composite mechanics and porous medium. The volume fraction, morphology and distribution of aggregates, as well as the interfacial transition zone (ITZ) are fully taken into consideration in this proposed model. The results show that the algorithm of M-T prediction scheme with high accuracy is relatively simple. 展开更多
关键词 M-T scheme chloride ion effective diffusion coefficient cement-based materials ITZ
暂未订购 下载PDF
Determination of Water Diffusion Coefficients and Dynamics in Adhesive/Carbon Fiber Reinforced Epoxy Resin Composite Joints 认领 引用 被引量：3
16
作者 WANG Chao WANG zhi +1 位作者 WANG Jing SU Tao 《Chemical Research in Chinese Universities》 SCIE CAS 2007年第4期474-478,共5页
To determinate the water diffusion coefficients and dynamics in adhesive/carben fiber reinforced epoxy resin composite joints, energy dispersive X-ray spectroscopy analysis（EDX） is used to establish the content chan... To determinate the water diffusion coefficients and dynamics in adhesive/carben fiber reinforced epoxy resin composite joints, energy dispersive X-ray spectroscopy analysis（EDX） is used to establish the content change of oxy- gen in the adhesive in adhesive/carbon fther reinforced epoxy resin composite joints. As water is made up of oxygen and hydrogen, the water diffusion coefficients and dynamics in adhesive/carben fiber reinforced epoxy resin composite joints can be obtained from the change in the content of oxygen in the adhesive during humidity aging, via EDX analy-sis. The authors have calculated the water diffusion coefficients and dynamics in the adhesive/carbon fiber reinforced epoxy resin composite joints with the aid of beth energy dispersive X-ray spectroscopy and elemental analysis. The de- termined results with EDX analysis are almost the same as those determined with elemental analysis and the results al- so show that the durability of the adhesive/carbon fther reinforced epoxy resin composite joints subjected to silane cou- pling agent treatment is better than those subjected to sand paper burnishing treatment and chemical oxidation treat- ment. 展开更多
关键词 Diffusion coefficient Dynamics Energy dispersive X-ray spectroscopy Elemental analysis Adhesive/ carbon fiber reinforced epoxy resin composites joint
暂未订购 下载PDF
Time Dependent Chloride Diffusion Coefficient in Concrete 认领 引用 被引量：5
17
作者 宋鲁光 孙伟 GAO Jianming 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2013年第2期314-319,共6页
In order to study how to correctly apply the two different time dependencies to service life prediction models, the definition of parameters in the time dependent equation using the long-term test method and the short... In order to study how to correctly apply the two different time dependencies to service life prediction models, the definition of parameters in the time dependent equation using the long-term test method and the short-term test method, and its relationship were discussed. The experimental results show that, as the two time dependencies have different meanings, they have different manners when handled in service life prediction models. Time dependency of chloride diffusion coefficients in concrete was obtained by fitting experimental data. A large number of accurate experimental data were required to fit the formula of time dependency to ensure the accuracy of service life prediction model. 展开更多
关键词 concrete time dependency chloride diffusion coefficient
暂未订购 下载PDF
Measurement of Diffusion Coefficients of Air in Silicone Oil and in Hydraulic Oil 认领 引用 被引量：6
18
作者 丁川 范毓润 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2011年第2期205-211,共7页
A piston-cylinder apparatus was established to measure the solubility and diffusivity of air in dimethyl silicone oils and in hydraulic oils based on the PVT state equation of air and the solution of unsteady one-dime... A piston-cylinder apparatus was established to measure the solubility and diffusivity of air in dimethyl silicone oils and in hydraulic oils based on the PVT state equation of air and the solution of unsteady one-dimensional diffusion equation.The measured diffusivity-temperature relation can be well fitted by the Arrhenius equation for engineering applications.The correlation between the solute diffusivity D and solvent viscosity μ is examined.In terms of Eyring＇s activation theory,the activation in the air-silicone-oil diffusion process is quite different from that in the momentum transport of the silicone oil：the activation entropy of the former is positive while that of latter is negative.However,the activation enthalpies of the two processes are in the same order of magnitude,which leads to the observation that Dμ/T is roughly constant. 展开更多
关键词 air silicone oil hydraulic oil diffusion coefficient viscosity
暂未订购 下载PDF
Multi-scale Modeling of the Effective Chloride Ion Diffusion Coefficient in Cement-based Composite Materials 认领 引用 被引量：2
19
作者 SUN Guowen SUN Wei +1 位作者 ZHANG Yunsheng LIUZhiyong 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2012年第2期364-373,共10页
N-layered spherical inclusions model was used to calculate the effective diffusion coefficient of chloride ion in cement-based materials by using multi-scale method and then to investigate the relationship between the... N-layered spherical inclusions model was used to calculate the effective diffusion coefficient of chloride ion in cement-based materials by using multi-scale method and then to investigate the relationship between the diffusivity and the microstructure of cement-basted materials where the microstructure included the interfacial transition zone(ITZ)between the aggregates and the bulk cement pastes as well as the microstructure of the bulk cement paste itself.For the convenience of applications,the mortar and concrete were considered as a four-phase spherical model,consisting of cement continuous phase,dispersed aggregates phase,interface transition zone and their homogenized effective medium phase.A general effective medium equation was established to calculate the diffusion coefficient of the hardened cement paste by considering the microstructure.During calculation,the tortuosity(n)and constrictivity factors(Ds/Do)of pore in the hardened pastes are n^3.2,Ds/Do=l.Ox 10-4 respectively from the test data.The calculated results using the n-layered spherical inclusions model are in good agreement with the experimental results;The effective diffusion coefficient of ITZ is 12 times that of the bulk cement for mortar and 17 times for concrete due to the difference between particle size distribution and the volume fraction of aggregates in mortar and concrete. 展开更多
关键词 multiscale chloride diffusion coefficient cement-based composite materials generaleffective medium theory composite spheres model microstructure
暂未订购 下载PDF
Hydrogen diffusion coefficient in liquid metals evaluated by solid-gas eutectic unidirectional solidification 认领 引用 被引量：2
20
作者 杨倩倩 刘源 李言祥 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2014年第12期4030-4037,共8页
Based on the solid-gas eutectic unidirectional solidification technique and the principle of unidirectional solidification of single-phase alloy, a new method for evaluating the diffusion coefficient of hydrogen in li... Based on the solid-gas eutectic unidirectional solidification technique and the principle of unidirectional solidification of single-phase alloy, a new method for evaluating the diffusion coefficient of hydrogen in liquid metals was proposed. Taking Cu-H2 system for example, the influences of argon partial pressure and superheat degree of melt on the diffusion coefficient of hydrogen in liquid metal were studied and the predicted values were similar to each other. The obtained temperature-dependent equation for diffusion coefficient of hydrogen in liquid copper is comparable with experimental data in literature, which validates the effectiveness of this method. The temperature-dependent equations for diffusion coefficient of hydrogen in liquid Mg, Si and Cu-34.6%Mn alloy were also evaluated by this method, along with the values at the melting point of each metal and alloy. 展开更多
关键词 hydrogen diffusion coefficient liquid metal solid-gas eutectic unidirectional solidification
暂未订购 下载PDF
已选0条
引用分析
参考文献
引证文献
 统计分析
检索结果
已选文献
上一页 1 2 … 18 下一页 到第 页
在线咨询 使用帮助 返回顶部 意见反馈