Quantitative Assessment of Hepatic Fibrosis by Contrast-enhanced Ultrasonography

Objective To explore the contrast-enhanced ultrasonographic features for quantitative assessment of hepatic fibrosis. Methods 86 patients with chronic viral hepatitis B were enrolled in this study from March 2007 to August 2009. The patients were classified into 5 groups (S0-S4) according to fibrosis stage evaluated with ultrasound guided liver biopsy. New contrast-enhanced ultrasonography (CEUS) features including area under the time-intensity curve (TIC) of portal venous phase/hepatic arterial phase (Qp/Qa) and intensity of portal venous phase/hepatic arterial phase (Ip/Ia) were used to detect the blood supply ratio (portal vein/hepatic artery) in each group. Arrival time of portal vein trunk (Tp) and decreasing rate of TIC (β ) were also analyzed. Results Qp/Qa and Ip/Ia decreased from S0 to S4, while Tp and β increased. These 4 features were significantly correlated with the degree of fibrosis (P<0.001) and were significantly different among the five groups (P<0.001). Sensitivity and specificity of Ip/Ia were 80% and 86% for groups ≥S1, 75% and 86% for groups ≥ S2, 71% and 84% for groups ≥ S3, and 76% and 80% for group S4, respectively. Sensitivity and specificity of Qp/Qa were 70% and 88% for groups ≥ S1, 80% and 76% for groups ≥ S2, 74% and 70% for groups ≥ S3, and 81% and 95% for group S4, respectively. Conclusion Ip/Ia and Qp/Qa could be adopted as reliable, non-invasive features for quantitative assessment of hepatic fibrosis.

PREPARATION OF POLYELECTROLYTE MULTILAYER COATED MICROBUBBLES FOR USE AS ULTRASOUND CONTRAST AGENT

Objeelive To prepare and characterize polyelectrolyte multilayer film coated microbubbles for use as ultrasound contrast agent （UCA） and evaluate its effects in ultrasonic imaging on normal rabbit＇s fiver parenchyma. Methods Perfluorocarbon （PFC）-containing microbubbles （ST68-PFC） were prepared by sonication based on suffactant （ Span 60 and Tween 80）. Subsequently, the resulting ST68-PFC microbubbles were coated using oppositely charged polyelectrolytes by microbubble-templated layer-by-layer self-assembly technique via electrostatic interaction. The enhancement effects in ultrasonic imaging on normal rabbit＇s liver parenchyma were assessed. Results The obtained microbubbles exhibited a narrow size distribution. The polyelectrolytes were successfully assembled onto the surface of ST68-PFC microbubbles. In vivo experiment showed that polyelectrolyte multilayer film coated UCA effectively enhanced the imaging of rabbit＇s liver parenchyma. Conclusions The novel microbubbles UCA coated with polyelectrolyte multilayer, when enabled more function, has no obvious difference in enhancement effects compared with the pre-modified microbubbles. The polymers with chemically active groups （ such as amino group and carboxyl group） can be used as the outermost layer for attachment of targeting ligands onto microbubbles, allowing selective targeting of the microbubbles to combine with desired sites.

Risk factor analysis and clinical decision tree model construction for diabetic retinopathy in Western China

BACKGROUND Diabetic retinopathy(DR)is the driving force of blindness in patients with type 2 diabetes mellitus(T2DM).DR has a high prevalence and lacks effective therapeutic strategies,underscoring the need for early prevention and treatment.Yunnan province,located in the southwest plateau of China,has a high prevalence of DR and an underdeveloped economy.AIM To build a clinical prediction model that will enable early prevention and treatment of DR.METHODS In this cross-sectional study,1654 Han population with T2DM were divided into groups without(n=826)and with DR(n=828)based on fundus photography.The DR group was further subdivided into non-proliferative DR(n=403)and proliferative DR(n=425)groups.A univariate analysis and logistic regression analysis were conducted and a clinical decision tree model was constructed.RESULTS Diabetes duration≥10 years,female sex,standing-or supine systolic blood pressure(SBP)≥140 mmHg,and cholesterol≥6.22 mmol/L were risk factors for DR in logistic regression analysis(odds ratio=2.118,1.520,1.417,1.881,and 1.591,respectively).A greater severity of chronic kidney disease(CKD)or hemoglobin A 1c increased the risk of DR in patients with T2DM.In the decision tree model,diabetes duration was the primary risk factor affecting the occurrence of DR in patients with T2DM,followed by CKD stage,supine SBP,standing SBP,and body mass index(BMI).DR classification outcomes were obtained by evaluating standing SBP or BMI according to the CKD stage for diabetes duration<10 years and by evaluating CKD stage according to the supine SBP for diabetes duration≥10 years.CONCLUSION Based on the simple and intuitive decision tree model constructed in this study,DR classification outcomes were easily obtained by evaluating diabetes duration,CKD stage,supine or standing SBP,and BMI.

Ultrasound Elastography of Ethanol-induced Hepatic Lesions:In Vitro Study

Objective To study the value of ultrasound elastography in evaluation of ethanol-induced lesions of liver. Methods Alcohol with a dose of 2 ml was injected into a fresh porcine liver under ultrasound guidance to create stiff necrosis. Then freehand elastography of the lesion from the identical scan plane was obtained with SONOLINE Antares system using VF10-5 probe at about every 30 seconds till 6 minutes later. The original high quality radiofrequency data were acquired through an ultrasound research interface which was provided by the ultrasound system. Then, corresponding elastograms were produced offline using cross-correlation technique and compared with gross pathology findings. Results Gray-scale sonogram showed a hyperechoic area with acoustic shadow below appeared immediately after alcohol injection. The hyperechoic area tended to be diffuse and its boundary to be illegible with time. On the contrary, the ethanol-induced lesion in elastogram appeared as a low swain hard region surrounded by high strain soft hepatic tissues, with clear but irregular boundaries. Sequential elastograms with the sketched lesion boundaries showed that the lesion area increased in the first 3 minutes after ethanol injection, and then reached a plateau which corresponding to gross specimen. Conclusion Ultrasound elastography is capable of detecting and evaluating the diffusion of ethanol-induced hepatic lesion, and more sensitive and accurate than routine sonography.

Rational design of new phases of tin monosulfide by first-principles structure searches

Tin monosulfide(Sn S), which is composed of earth-abundant elements, holds promise as useful high-performance solar absorber and thermoelectric material. In addition to the ground-state Pnma phase, a series of metastable phases in different crystalline structures have been reported experimentally or theoretically, yet the phase stability diagrams remain elusive. In this article, we provide a comprehensive materials design study of new phases of Sn S using first-principles global optimization structure search calculations. We find that the two-dimensional layered phases are generally more energetically favored than the three-dimensional connected phases. In addition, we discover several new phases with comparable energetics. Four lower-energy phases show clear phonon stabilities evidenced by an absence of imaginary modes. The electronic band structures, carrier transport properties, and absorption spectra of the newly discovered phases are investigated and discussed toward potential applications for solar cells and thermoelectric devices.

Effects of light curing modes and ethanol-wet bonding on dentin bonding properties

Objective： This study explored the effects of different light curing modes and ethanol-wet bonding on dentin bonding strength and durability. Methods： A total of 54 molars were randomly divided into three groups： Single Bond 2, Gluma Comfort Bond, and N-Bond. Based on the three light-curing modes and presence or absence of eth- anol pretreatment, the samples were assigned to six subgroups： high-light mode, ethanol pretreatment＋high-light mode, soft-start mode, ethanol pretreatment＋soft-start mode, standard mode, and ethanol pretreatment＋standard mode. All samples were bonded with resin based on the experimental groups. After 24 h and 6 months of water storage, a universal testing machine was used to measure microtensile bond strength. Scanning electron microscopy （SEM） was applied to observe mixed layer morphology. Results： The 24-h and 6-month microtensile bond strengths of the ethanol pretreatment groups were significantly higher than those of the non-ethanol pretreatment groups at the same light modes （P〈0.05）. With or without ethanol pretreatment, the microtensile bond strengths of the high-light modes were significantly lower than those of the soft-start modes and standard modes （P〈0.05）. The microtensile bond strengths of samples from the 6-month water storage group significantly decreased compared with those of samples from the 24-h water storage group （P〈0.05）. The soft-start groups and standard groups formed better mixed layers than the high-light mode groups, whereas the ethanol pretreatment groups formed more uniform mixed layers than those without ethanol pretreatment. Conclusions： Ethanol-wet bonding technique, soft-start, and standard modes could improve dentin bonding properties.