RESUMEN
In this work, the long-term skid resistance attenuation law of asphalt mixtures in the presence of aeolian sand was studied. Four types of asphalt mixtures underwent skid resistance abrasion tests using an accelerated loading tester. The pendulum value (BPN) and structure depth (MTD) of these four mixtures were determined under various conditions of sand density and abrasion times. The correlation between the BPN and density and the number of times of abrasion were investigated, respectively, to analyze the skid resistance attenuation law at the microscopic and macroscopic levels. Our results indicate that the skid resistance of the four types of asphalt mixtures initially decreased and subsequently reached a stable state. Sand density primarily influences skid resistance during the initial stage, while the number of abrasions becomes the dominant factor affecting skid resistance in the later stages.
RESUMEN
The influence of sand accumulation on the skid resistance of asphalt pavement was studied. Many scholars have researched the anti-skid performance of conventional asphalt pavements. However, there is a lack of research on the anti-skid performance of desert roads under the condition of sand accumulation. In this study, AC-13 and AC-16 asphalt mixtures were used. The British Pendulum Number (BPN) under different sand accumulations was measured with a pendulum friction coefficient meter, and the Ames engineering texture scanner was used to obtain different sand accumulations. The texture index of asphalt mixture was used to study the macro and micro texture of asphalt pavement under different amounts of sand accumulation, and the degree of influence of different particle sizes on BPN was obtained through gray correlation analysis. The test results show that the presence of aeolian sand has a significant impact on the macro and micro texture of the asphalt pavement and will cause the anti-skid performance to decrease. Moreover, there is an apparent positive linear correlation between the road surface texture index and BPN. The research results may provide reference and reference for the design and maintenance of desert highways.
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BACKGROUND/AIMS: Absence of curative treatment creates urgent need for new strategies for unresectable hepatoma. Based on former discoveries of good liver cell compatibility, safety and tumour-specific inhibition of hydroxyapatite nanoparticles (nHAP), this work tries to make nHAP serve as gene vector in the hepatoma-targeted trans-arterial embolization (TAE) gene therapy to elevate and synergize the therapeutic efficacy of TAE and target gene therapy. METHOD: Following dosage and ratio optimization, polypolex formed by surface modified nHAP and p53 expressing plasmid was applied in vitro for human hepatoma HePG2 cell, and then in vivo for rabbit hepatic VX2 tumour by injection of polypolex/lipodoil emulsion to the hepatic artery in a tumour-target manner. RESULTS: In vitro, the polypolex transfected only about 5% HepG2 cells, but can elevate the inhibition of its growth and apoptosis in a much more degree while keeping safe to the normal hepatocyte line, L02. In vivo, the emulsion, with better dispersion than the polypolex and more specific tumour-target than lipiodol, mediated specific 4% p53 expression and antitumoural nanoparticle retention in the target tumour site, also significantly reduced tumour growth and prolonged the animal survival times more than the lipiodol (P < 0.05). CONCLUSIONS: In all, this new treatment based on nHAP can enhance therapeutic effect of HCC safely both in vitro and in vivo.
Asunto(s)
Carcinoma Hepatocelular/terapia , Durapatita/administración & dosificación , Embolización Terapéutica , Terapia Genética/métodos , Neoplasias Hepáticas/terapia , Nanopartículas , Animales , Apoptosis , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/patología , Proliferación Celular , Aceite Etiodizado/administración & dosificación , Estudios de Factibilidad , Femenino , Regulación Neoplásica de la Expresión Génica , Técnicas de Transferencia de Gen , Células Hep G2 , Humanos , Inyecciones Intraarteriales , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patología , Masculino , Necrosis , Conejos , Factores de Tiempo , Transfección , Carga Tumoral , Proteína p53 Supresora de Tumor/genética , Proteína p53 Supresora de Tumor/metabolismoRESUMEN
AIM: To investigate the value of contrast-enhanced C3-MODE technology in differentiating malignant nodules of liver from the benign ones. METHODS: Forty-six nodules in 36 patients (29 men and 7 women) were studied by contrast-enhanced C3-MODE technology and contrast-enhanced CT in 1 wk before the biopsy or operation. A low MI monitor and a high MI flash imaging were intermittently performed. After the injection of contrast agent, the period from 10 to 30 s and the time later than 100 s were respectively defined as early arterial phase and the late phase. The vascularities of the liver nodules in the two phases were combined for differential diagnosis. Corresponding to the pathological diagnosis, the accuracy, sensitivity and specificity of contrast-enhanced C3-MODE technology were compared to those of contrast-enhanced CT. RESULTS: By C3-MODE technology, 33 of the 46 liver nodules were demonstrated as defected area in the late phase and were diagnosed as malignant tumors. Of them, 28 with hypervascularity in the early arterial phase were assessed as hepatocellular carcinoma, the other five nodules with rim-like enhancement in the early arterial phase were diagnosed as metastatic tumors. Thirteen nodules were shown as iso or hypervascularity in the late phase as well as centripetal filling in the early arterial phase and we made a diagnosis of hemangioma. Corresponding to the pathological results, the sensitivity, specificity and accuracy of contrast-enhanced C3-MODE technology in differentiating malignant and benign nodules in the liver were 97.0%, 92.3% and 95.7%, respectively. With comparison to those of contrast CT (sensitivity, 94.1%; specificity, 91.7%; accuracy, 93.5%), the difference was not significant. CONCLUSION: Contrast-enhanced C3-MODE technology can effectively differentiate malignant liver tumors from the benign nodules. It highly agrees diagnostically with the pathology. We suggest that it provides a new approach for differential diagnosis of liver nodules in addition to contrast-enhanced CT.
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Carcinoma Hepatocelular/ultraestructura , Hígado Graso/diagnóstico por imagen , Neoplasias Hepáticas/diagnóstico por imagen , Ultrasonografía/métodos , Adenocarcinoma/patología , Adenocarcinoma/ultraestructura , Adulto , Anciano , Biopsia , Carcinoma Hepatocelular/patología , Medios de Contraste , Diagnóstico Diferencial , Hígado Graso/patología , Femenino , Hemangioma/diagnóstico por imagen , Hemangioma/patología , Hepatitis B/diagnóstico por imagen , Hepatitis B/patología , Humanos , Neoplasias Hepáticas/patología , Masculino , Persona de Mediana Edad , Sensibilidad y EspecificidadRESUMEN
AIM: To evaluate the therapeutic effect and the indication of percutaneous ethanol injection (PEI), radiofrequency ablation (RFA) and their combination in treatment of hepatocellular carcinoma (HCC). METHODS: Two hundred and fifty-five patients with HCC received treatment of PEI, RFA or their combination. Group 1 (< 3 cm in diameter, n=85) was treated with PEI, group 2 (< 3 cm in diameter, n=153) with RFA. Group 3 (> 3 cm in diameter, n=86) was divided into two groups. Group 3a (n=34) was treated with RFA, while group 3b (n=52) was treated with RFA for 2 wk after transcatheter arterial chemoembolization or PEI. Contrast-enhanced sonography was performed for 61 patients before and after RFA. Liver function and serum alpha-fetoprotein (AFP) were measured for all patients. Changes of the lesions on ultrasound and contrast-enhanced CT/MRI were evaluated for assessing the therapeutic responses. The 1-, 2-, 3- and 5-year survival rates were recorded after treatment. RESULTS: In group 1, the complete necrosis rate of lesions after 1 mo was 77.6% (66/85). The level of AFP declined conspicuously after 1 mo. The 1-, 2-, 3- and 5-year survival rate after treatment was 80.0% (52/65), 60.4% (32/53), 52.5% (21/40) and 33.3% (7/21), respectively. In group 2, the complete necrosis rate of lesions after 1 moh was 92.2% (141/153). The level of AFP decreased conspicuously after 1 mo. The 1-, 2-, 3- and 5-year survival rate after treatment was 94.6% (88/93), 73.2% (52/71), 63.5% (33/52) and 46.4% (13/28), respectively. In group 3a, the complete necrosis rate of lesions after 1 mo was 23.5% (8/34). AFP dropped down to the normal level in only one patient after 1 mo. The 1-, 2- and 3-year survival rate after treatment was 47.6% (10/21), 42.9% (6/14) and 27.3% (3/11), respectively. Only one patient was still alive after 5 years. In group 3b, the complete necrosis rate of lesions after 1 mo was 57.7% (30/52). The level of AFP decreased after 1 mo. The 1-, 2-, 3- and 5-year survival rate after treatment was 68.6% (24/35), 46.2% (12/26), 36.8% (7/19) and 27.3% (3/11), respectively. CONCLUSION: The therapeutic effect of RFA on small HCC is better than that of PEI. Small HCC is the optimal indication of RFA. For recurrent HCC (diameter > 3 cm), the combined treatment of RFA and PEI/ACE should be used.