Two-dimensional graphene offers interesting electronic,thermal,and mechanical properties that are currently being explored for advanced electronics,membranes,and composites.Here we synthesize and explore the biologica...Two-dimensional graphene offers interesting electronic,thermal,and mechanical properties that are currently being explored for advanced electronics,membranes,and composites.Here we synthesize and explore the biological applications of nano-graphene oxide(NGO),i.e.,single-layer graphene oxide sheets down to a few nanometers in lateral width.We develop functionalization chemistry in order to impart solubility and compatibility of NGO in biological environments.We obtain size separated pegylated NGO sheets that are soluble in buffers and serum without agglomeration.The NGO sheets are found to be photoluminescent in the visible and infrared regions.The intrinsic photoluminescence(PL)of NGO is used for live cell imaging in the near-infrared(NIR)with little background.We found that simple physisorption viaπ-stacking can be used for loading doxorubicin,a widely used cancer drug onto NGO functionalized with antibody for selective killing of cancer cells in vitro.Owing to its small size,intrinsic optical properties,large specifi c surface area,low cost,and useful non-covalent interactions with aromatic drug molecules,NGO is a promising new material for biological and medical applications.展开更多
AIM:To investigate the diagnostic accuracy of acoustic radiation force impulse (ARFI) imaging as a noninvasive method for the assessment of liver fibrosis in chronic hepatitis C (CHC) patients.METHODS:We performed a p...AIM:To investigate the diagnostic accuracy of acoustic radiation force impulse (ARFI) imaging as a noninvasive method for the assessment of liver fibrosis in chronic hepatitis C (CHC) patients.METHODS:We performed a prospective blind com-parison of ARFI elastography,APRI index and FibroMax in a consecutive series of patients who underwent liver biopsy for CHC in University Hospital Bucharest. His-topathological staging of liver fibrosis according to the METAVIR scoring system served as the reference. A to-tal of 74 patients underwent ARFI elastography,APRI index,FibroMax and successful liver biopsy. RESULTS:The noninvasive tests had a good correlation with the liver biopsy results. The most powerful test in predicting fibrosis was ARFI elastography. The diagnostic accuracy of ARFI elastography,expressedas area under receiver operating characteristic curve (AUROC) had a validity of 90.2% (95% CI AUROC = 0.831-0.972,P < 0.001) for the diagnosis of significant f ibrosis (F ≥ 2). ARFI sonoelastography predicted even better F3 or F4 fibrosis (AUROC = 0.993,95% CI = 0.979-1).CONCLUSION:ARFI elastography had very good accuracy for the assessment of liver fibrosis and was superior to other noninvasive methods (APRI Index,FibroMax) for staging liver fibrosis.展开更多
Hepatocellular carcinoma(HCC)is one of the most prevalent cancers globally.In contrast to the declining death rates observed for all other common cancers such as breast,lung,and prostate cancers,the death rates for HC...Hepatocellular carcinoma(HCC)is one of the most prevalent cancers globally.In contrast to the declining death rates observed for all other common cancers such as breast,lung,and prostate cancers,the death rates for HCC continue to increase by^2e3%per year because HCC is frequently diagnosed late and there is no curative therapy for an advanced HCC.The early diagnosis of HCC is truly a big challenge.Over the past years,the early diagnosis of HCC has relied on surveillance with ultrasonography(US)and serological assessments of alpha-fetoprotein(AFP).However,the specificity and sensitivity of US/AFP is not satisfactory enough to detect early onset HCC.Recent technological advancements offer hope for early HCC diagnosis.Herein,we review the progress made in HCC diagnostics,with a focus on emerging imaging techniques and biomarkers for early disease diagnosis.展开更多
Objective To investigate the rule of the aquaporin 4 (AQP4) expression in acute ischemic brain edema, and to study the correlation between AQP4 expression and diffusion weighted imaging (DWI) Methods Thirty ...Objective To investigate the rule of the aquaporin 4 (AQP4) expression in acute ischemic brain edema, and to study the correlation between AQP4 expression and diffusion weighted imaging (DWI) Methods Thirty six Wistar rats were divided into 2 groups randomly, control group (n=12) and operation group (n=24) in which right middle cerebral artery of each animal had been occluded unilaterally (MCAO) at interval times of: 15 minutes, 30 minutes, 1 hours, 3 hours, 6 hours and 24 hours, respectively The operation process of the control group was the same as the operation group except for the MCAO All groups were examined using DWI The apparent diffusion coefficient (ADC), relative density (rd) and relative area (rs) of the biggest hyperintensity signal layer on DWI were measured After that the animals were sacrificed and perfused with the mixture solution consisting of TTC The biggest layers of the ischemic cerebral tissues in each rat corresponding to the DWI were stained with TTC and examined with immunochemistry (△S) , in situ hybridization (α) and histology Results There was no significant change in the control group In the operation group, a hyperintensity signal was found in the DWI of the right MAC territory at 15 minutes after MCAO The ADC value decreased quickly within one hour after MCAO, while the AQP4 expression, rd DWI and rs DWI increased rapidly during this stage As time progressed, the ADC value decreased further to (2 1±0 6)×10 4 mm 2/s at 3 hours, and then began to increase slowly till 24 hours But the AQP4 expression (△S and α) and rd as well as the rs continuously increased slowly between 1 hour and 6 hours after MCAO, followed a peak after 6 hours The AQP4 expression (α) showed a positive relationship with the rs DWI, they all presented two peaks and a plateau The corresponding sequential pathologic changes were a gradual increase of intracellular edema (within one hour), then an emergence of vasogenic edema (1-6 hours), and fin展开更多
基金by NIH-NCI funded CCNE TR at Stanford University.We are grateful to Drs.Alice Fan and Dean Felsher for providing the antibodies used in this work.
文摘Two-dimensional graphene offers interesting electronic,thermal,and mechanical properties that are currently being explored for advanced electronics,membranes,and composites.Here we synthesize and explore the biological applications of nano-graphene oxide(NGO),i.e.,single-layer graphene oxide sheets down to a few nanometers in lateral width.We develop functionalization chemistry in order to impart solubility and compatibility of NGO in biological environments.We obtain size separated pegylated NGO sheets that are soluble in buffers and serum without agglomeration.The NGO sheets are found to be photoluminescent in the visible and infrared regions.The intrinsic photoluminescence(PL)of NGO is used for live cell imaging in the near-infrared(NIR)with little background.We found that simple physisorption viaπ-stacking can be used for loading doxorubicin,a widely used cancer drug onto NGO functionalized with antibody for selective killing of cancer cells in vitro.Owing to its small size,intrinsic optical properties,large specifi c surface area,low cost,and useful non-covalent interactions with aromatic drug molecules,NGO is a promising new material for biological and medical applications.
基金Supported by Grant 41066/2007, financed by the Ministry of Education and Research
文摘AIM:To investigate the diagnostic accuracy of acoustic radiation force impulse (ARFI) imaging as a noninvasive method for the assessment of liver fibrosis in chronic hepatitis C (CHC) patients.METHODS:We performed a prospective blind com-parison of ARFI elastography,APRI index and FibroMax in a consecutive series of patients who underwent liver biopsy for CHC in University Hospital Bucharest. His-topathological staging of liver fibrosis according to the METAVIR scoring system served as the reference. A to-tal of 74 patients underwent ARFI elastography,APRI index,FibroMax and successful liver biopsy. RESULTS:The noninvasive tests had a good correlation with the liver biopsy results. The most powerful test in predicting fibrosis was ARFI elastography. The diagnostic accuracy of ARFI elastography,expressedas area under receiver operating characteristic curve (AUROC) had a validity of 90.2% (95% CI AUROC = 0.831-0.972,P < 0.001) for the diagnosis of significant f ibrosis (F ≥ 2). ARFI sonoelastography predicted even better F3 or F4 fibrosis (AUROC = 0.993,95% CI = 0.979-1).CONCLUSION:ARFI elastography had very good accuracy for the assessment of liver fibrosis and was superior to other noninvasive methods (APRI Index,FibroMax) for staging liver fibrosis.
文摘Hepatocellular carcinoma(HCC)is one of the most prevalent cancers globally.In contrast to the declining death rates observed for all other common cancers such as breast,lung,and prostate cancers,the death rates for HCC continue to increase by^2e3%per year because HCC is frequently diagnosed late and there is no curative therapy for an advanced HCC.The early diagnosis of HCC is truly a big challenge.Over the past years,the early diagnosis of HCC has relied on surveillance with ultrasonography(US)and serological assessments of alpha-fetoprotein(AFP).However,the specificity and sensitivity of US/AFP is not satisfactory enough to detect early onset HCC.Recent technological advancements offer hope for early HCC diagnosis.Herein,we review the progress made in HCC diagnostics,with a focus on emerging imaging techniques and biomarkers for early disease diagnosis.
基金theNationalNaturalScienceFoundationofChina (No 3 0 0 70 2 47)
文摘Objective To investigate the rule of the aquaporin 4 (AQP4) expression in acute ischemic brain edema, and to study the correlation between AQP4 expression and diffusion weighted imaging (DWI) Methods Thirty six Wistar rats were divided into 2 groups randomly, control group (n=12) and operation group (n=24) in which right middle cerebral artery of each animal had been occluded unilaterally (MCAO) at interval times of: 15 minutes, 30 minutes, 1 hours, 3 hours, 6 hours and 24 hours, respectively The operation process of the control group was the same as the operation group except for the MCAO All groups were examined using DWI The apparent diffusion coefficient (ADC), relative density (rd) and relative area (rs) of the biggest hyperintensity signal layer on DWI were measured After that the animals were sacrificed and perfused with the mixture solution consisting of TTC The biggest layers of the ischemic cerebral tissues in each rat corresponding to the DWI were stained with TTC and examined with immunochemistry (△S) , in situ hybridization (α) and histology Results There was no significant change in the control group In the operation group, a hyperintensity signal was found in the DWI of the right MAC territory at 15 minutes after MCAO The ADC value decreased quickly within one hour after MCAO, while the AQP4 expression, rd DWI and rs DWI increased rapidly during this stage As time progressed, the ADC value decreased further to (2 1±0 6)×10 4 mm 2/s at 3 hours, and then began to increase slowly till 24 hours But the AQP4 expression (△S and α) and rd as well as the rs continuously increased slowly between 1 hour and 6 hours after MCAO, followed a peak after 6 hours The AQP4 expression (α) showed a positive relationship with the rs DWI, they all presented two peaks and a plateau The corresponding sequential pathologic changes were a gradual increase of intracellular edema (within one hour), then an emergence of vasogenic edema (1-6 hours), and fin
