从评报看彩报印刷质量的提高——访中国报协印刷委员会评报组

中国经济的持续发展,促进了人们对报纸需求量的大幅增长,使我国报业飞速发展.多年来,人们完全能切实地感受到我国报纸日新月异的变化,从原来的黑白铅印报,到后来的胶印黑白报、套红报,再到彩报、用铜版纸印刷的豪华版彩报,报纸已成为老百姓生活中不可缺少的,最普及的读物.

高职院校项目教学的有效评价方法探索

项目教学在全国各高职院校广泛推广,这种教师指导学生主导的教学模式是离职课程改革的必然趋势,教学模式的改革必然会带动课程教学评价方式的改革,课堂教学评价是否有效将直接影响到项目教学的质量。在课程教学实践中,笔者根据项目教学的特点,探索适合项目教学的评价方法。笔者将结合AutoCAD课程项目教学实践,探讨项目教学评价原则和方法,提出以能力考核为主开展自评、组评、师评的评价设计方案,以及评价方案在项目教学评价中的实施方法。

目标教学中目标达成度的评价问题

为了认真贯彻实施部颁新教学计划和大纲，我校于１９９４年秋季开始在各专业开展了目标教学。３年来的学习和实践，大家对目标教学理论有了深入的认识，对其操作程序已基本掌握。在实践中，笔者更进一步认识到：目标教学与传统教学相比，除了目标明确、学有定向外，另一大...

关于推行发展性教学评价制度的思考

在参考现代中西方教学评价资料与理论的基础上,运用访谈、问卷、文献分析等方法对郑州卫校现行教学评价制度进行了实证研究,在肯定成绩的同时分析了其存在的4个问题,并提出了6条改革建议.

以学生为主体的实践课程考核方式的创新探索

该文以高校电子专业综合实践课程为背景,分析了国内目前实践教学课程考核评价机制存在的问题和主要原因。为了比较客观和全面地评价学生在实践课程中的表现,充分发挥课程考核在实践课程教学体系中的作用,借鉴了国外高校课程考核方式,提出了一种新的实践课程考核评价制度,并给出了具体的实施方式和相关规则。新的课程考核方式以学生为考核主体,通过"组内自评"和"分组考核"的方式,促进学生自觉、自主学习,调动学生主动实践和学习的热情,从而有效提高学生的综合实验能力。实践表明,该考核方式可供其他电类理论、实践课程及相关设计类课程参考和借鉴。

Callus Induction of Alfalfa and Evaluation of Callus Tolerance to Acid and Aluminum

Medicago is an important grass in the legume family,which is suitable to be grown in neutral or alkalescent soils,and hence,can be widely spread in south of China with low pH value.It is one of major objectives to cultivate acid-aluminum tolerant species.In the research,6 high-quality species with high-yielding potential were taken as materials to make evaluation on acid-aluminum tolerance by cell-culture technique,and the results showed that tolerance capacity from high to low was GT13R＞Muge 701=Muge 702＞Acrora＞AC-3＞Sheshou No.2=Medicago sativa.

Image quality assessment based on perceptual grouping

To further explore the human visual system（ HVS）,the perceptual grouping（ PG）, which has been proven to play an important role in the HVS, is adopted to design an effective image quality assessment（ IQA） model. Compared with the existing fixed-window-based models, the proposed one is an adaptive window-like model that introduces the perceptual grouping strategy into the IQA model. It works as follows： first,it preprocesses the images by clustering similar pixels into a group to the greatest extent; then the structural similarity is used to compute the similarity of the superpixels between reference and distorted images; finally, it integrates all the similarity of superpixels of an image to yield a quality score. Experimental results on three databases（ LIVE, IVC and MICT） showthat the proposed method yields good performance in terms of correlation with human judgments of visual quality.

A personalized trustworthy service selection method

A personalized trustworthy service selection method is proposed to fully express the features of trust, emphasize the importance of user preference and improve the trustworthiness of service selection. The trustworthiness of web service is defined as customized multi-dimensional trust metrics and the user preference is embodied in the weight of each trust metric. A service selection method combining AHP （analytic hierarchy process） and PROMETHEE （preference ranking organization method for enrichment evaluations） is proposed. AHP is used to determine the weights of trust metrics according to users＇ preferences. Hierarchy and pairwise comparison matrices are constructed. The weights of trust metrics are derived from the highest eigenvalue and eigenvector of the matrix. to obtain the final rank of candidate services. The preference functions are defined according to the inherent characteristics of the trust metrics and net outranking flows are calculated. Experimental results show that the proposed method can effectively express users＇ personalized preferences for trust metrics, and the trustworthiness of service ranking and selection is efficiently improved.

P16 gene hypermethylation and hepatocellular carcinoma:A systematic review and meta-analysis

AIM:To quantitatively investigate the effect of p16 hypermethylation on hepatocellular carcinoma (HCC) and hepatocirrhosis using a meta-analysis of available casecontrol studies.METHODS:Previous studies have primarily evaluated the incidence of p16 hypermethylation in HCC and corresponding control groups,and compared the incidence of p16 hypermethylation in tumor tissues,pericancer liver tissues,normal liver tissues and non-tumor liver tissues with that in other diseases.Data regarding publication information,study characteristics,and incidence of p16 hypermethylation in both groups were collected from these studies and summarized.RESULTS:Fifteen studies,including 744 cases of HCC and 645 non-tumor cases,were identified for meta-analysis.Statistically significant odds ratios (ORs) of p16 hypermethylation were obtained from tumor tissues and non-tumorous liver tissues of HCC patients (OR 7.04,95% CI:3.87%-12.78%,P < 0.0001),tumor tissues of HCC patients and healthy liver tissues of patients with other diseases (OR 12.17,95% CI:6.64%-22.31%,P < 0.0001),tumor tissues of HCC patients and liver tissues of patients with non-tumorous liver diseases (OR 6.82,95% CI:4.31%-10.79%,P < 0.0001),and cirrhotic liver tissues and non-cirrhotic liver tissues (OR 4.96,95% CI:1.45%-16.96%,P=0.01).The pooled analysis showed significantly increased ORs of p16 hypermethylation (OR 6.98,95% CI:4.64%-10.49%,P < 0.001) from HCC tissues and cirrhotic tissues.CONCLUSION:P16 hypermethylation induces the inactivation of p16 gene,plays an important role in hepatocarcinogenesis,and is associated with an increased risk of HCC and liver cirrhosis.

Diagnosis of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the commonest cancers worldwide, particularly in parts of the developing world, and is increasing in incidence. This article reviews the current modalities employed for the diagnosis of HCC, including serum markers, radiological techniques and histological evaluation, and summarises international guidelines for the diagnostic approach to HCC.

Usefulness of a scoring system in the interpretation of histology in neonatal cholestasis

AIM:To ascertain the usefulness of a histological scoring system devised to assist in the interpretation of liver histology in neonatal cholestasis(NC) .METHODS:Liver biopsy specimens obtained from infants with NC referred to a tertiary pediatric unit in Malaysia were prospectively studied.The first author,blinded to the final diagnosis,devised the histological diagnosis based on a 7-feature(portal ductal proliferation,bile plugs in portal ductules,portoportal bridging,lymphocytic infiltration in portal region,multinucleated hepatocytes,neutrophilic infiltration,hepatocellular swelling) ,15-point(0 to 15) scoring system.The author classified the histological diagnosis as either biliary atresia(BA) or neonatal hepatitis(NH,all other diagnoses) ,and subsequently compared the author's diagnosis with the final diagnosis.RESULTS:Eighty-four biopsy specimens obtained from 78 patients were reviewed.Without the scoring system,BA was correctly diagnosed by the author histologically in 30 cases,labelled as NH in 3.For other diagnoses,BA was excluded correctly in 33 cases and mislabeled as BA in 2 cases.The overall sensitivity for BA was 91%,specificity 86% and accuracy 88%.With the scoring system,a score of ≥ 7 had the best diagnostic utility to differentiate BA from other intrahepatic cholestasis histologically(sensitivity 88%,specificity 94%,accuracy 92%) .Four patients with a score < 7 had BA,and 3 patients with a score ≥ 7 had NH.CONCLUSION:A 7-feature,15-point histological scoring system had good diagnostic accuracy in the interpretation of liver histology in neonatal cholestasis.

Effects of different periods of renal ischemia on liver as a remote organ

AIM:To assess the hepatic changes after induction of different periods of renal ischemia. METHODS:Rats were subjected to either sham operation or ischemia (30,45 and 60 min) followed by 60 min reperfusion. Liver and renal functional indices were measured. Hepatic glutathione (GSH) and ferric reducing antioxidant power levels and the concentration of interleukin (IL)-10 and tumor necrosis factor (TNF-α) were evaluated. Portions of liver and kidney tissues were fixed for histological evaluation. RESULTS:Forty-five minutes renal ischemia followed by 60 min reperfusion caused significant changes in liver structure and a significant reduction in renalfunction. These rats showed a significant decrease in liver GSH,as well as a significant increase in TNF-α and IL-10 concentrations. These results demonstrated that renal ischemia caused changes in liver histology,function,oxidative stress and inflammatory status,which led to a reduction in hepatic antioxidant capacity. With 30 min ischemia,the magnitude of these changes was less than those with 45 or 60 min ischemia.CONCLUSION:A minimum of 45 min ischemia is needed to study the effects of renal injury on the liver as a remote organ.

Classification tool for the systematic histological assessment of hepatocellular carcinoma, macroregenerative nodules, and dysplastic nodules in cirrhotic liver

AIM： To design a classification tool for the histological assessment of hepatocellular carcinoma （HCC）, dysplastic nodules （DN）, and macroregenerative nodules （MRN） in cirrhotic liver. METHODS： Two hundred and twelve hepatocellular nodules （106 HCC; 74 IRN, 32 DN） were assessed systematically, quantitatively, and semiquantitatively as appropriate for 10 histological features that have been described as helpful in distinguishing small HCC, DN, and MRN in cirrhotic livers. The data were analyzed by multiple correspondence analysis （MCA）. RESULTS： HCA distributed HCC, DN, and HRN as defined by traditional histological evaluation as well as the individual histological variables, in a ＂malignancy scale＂. Based on the MCA data representation, we created a classification tool, which categorizes an individual nodular lesion as MRN, DN, or HCC based on the balance of all histological features （i.e., vascular invasion, capsular invasion, tumor necrosis, tumor heterogeneity, reticulin loss, capillarization of sinusoids, trabecular thickness, nuclear atypia, and mitotic activity）. The classification tool classified most （83%） of a validation set of 47 nodules in the same way as the routine histological assessment. No discrepandes were present for DN and MRN between the routine histological assignment and the dassification tool. Of 25 HCC assigned by routine assessment in the validation set, 8 were assigned to the DN category by the classification tool. CONCLUSION： We have designed a classification tool for the histological assessment of HCC and its putative precursors in cirrhotic liver. Application of this toolsystematically records histological features of diagnostic importance in the evaluation of small HCC.

Omentum facilitates liver regeneration

AIM:To investigate the mechanism of liver regeneration induced by fusing the omentum to a small traumatic injury created in the liver. We studied three groups of rats. In one group the rats were omentectomized; in another group the omentum was left in situ and was not activated,and in the third group the omentum was activated by polydextran particles. METHODS:We pre-activated the omentum by injecting polydextran particles and then made a small wedge wound in the rat liver to allow the omentum to fuse to the wound. We monitored the regeneration of the liver by determining the ratio of liver weight/body weight,by histological evaluation (including immune staining for cytokeratin-19,an oval cell marker),and by testing for developmental gene activation using reverse transcription polymerase chain reaction (RT-PCR). RESULTS:There was no liver regeneration in the omentectomized rats,nor was there significant regeneration when the omentum was not activated,even though in this instance the omentum had fusedwith the liver. In contrast,the liver in the rats with the activated omentum expanded to a size 50% greater than the original,and there was histologically an interlying tissue between the wounded liver and the activated omentum in which bile ducts,containing cytokeratin-19 positive oval cells,extended from the wound edge. In this interlying tissue,oval cells were abundant and appeared to proliferate to form new liver tissue. In rats pre-treated with drugs that inhibited hepatocyte growth,liver proliferation was ongoing,indicating that regeneration of the liver was the result of oval cell expansion. CONCLUSION:Activated omentum facilitates liver regeneration following injury by a mechanism that depends largely on oval cell proliferation.

Non-classical phenotypes of autoimmune hepatitis and advances in diagnosis and treatment

Non-classical manifestations of autoimmune hepatitis can delay diagnosis and treatment. Our aims were to describe the clinical phenotypes that can confound the diagnosis, detail scoring systems that can ensure their recognition, and outline advances in treatment that can improve their outcome. Prime source and review articles in English were selected throuqh Medline from 1970-2008 and assimilated into personal libraries spanning 32 years. Acute severe or asymptomatic presentations and atypical histological findings,including centrilobular zone 3 necrosis and concurrent bile duct changes, are compatible with the diagnosis. Cholangiographic abnormalities may be present in children and adults with the disease, and autoimmune hepatitis must be considered in patients without autoantibodies or with antimitochondrial antibodies and no other cholestatic features. Asymptomatic patients frequently become symptomatic; mild disease can progress; and there are no confident indices that justify withholding treatment. Two diagnostic scoring systems with complementary virtues have been developed to evaluate patients with confusing features. Normal liver tests and tissue constitute the optimal end point of treatment, and the first relapse is an indication for long- term azathioprine therapy. Cyclosporine, tacrolimus and mycophenolate mofetil are promising salvage therapies,and budesonide with azathioprine may be a superior frontline treatment. We conclude that the non-classical phenotypes of autoimmune hepatitis can be recognized promptly, diagnosed accurately, and treated effectively.

Evaluation on prediction abilities of constitutive models considering FEA application

Constitutive model plays an important role in the numerical simulations of metal forming. However, th~ influence of the models on the calculation is vague. Based on the stress-strain data of A1 7050 and Ti-6A1-4V alloy generated by isothermal compressive tests, the Johnson-Cook （JC） and Arrhenius-type （A-type） hyperbolic sine model were fitted to obtain the constants. Flow stresses directly calculated by the equations were compared with th~ experiment results, and rigid-plastic finite element analyses （FEA） utilizing these models were employed to simulate th~ same compression processes. The results show that A-type model has higher accuracy in the direct prediction of roy stress, even outside of the fit domain. The simulation results using A-type model also have higher agreement with th~ experiment; however, the suitability is affected by the referential parameters employed in the regression process, h terms of the overall deformation and strain distributions, there are slight differences among the simulation results usint these two models.

Liver tumor infiltrating lymphocytes: Comparison of hepatocellular and cholangiolar carcinoma

AIM: To investigate the role of tumor inf iltrating lym-phocytes (TIL) in primary hepatocellular and cholangio-lar carcinomas of the liver.METHODS: Immunohistochemical analysis was per-formed including antibodies to CD3, CD4, CD8, CD20, CD56 and TIA-1 in formalin-f ixed and paraff in-embed-ded tissue of 35 liver resection specimens of hepatocel-lular or cholangiocellular carcinomas. Semiquantitative evaluation was performed with emphasis on the area of the tumor itself and of the tumor/liver interface.RESULTS: All hepatocellular carcinomas showed in-filtration of lymphocytes predominantly around the tumor in the tumor/liver interface consisting mainly of CD3+ CD4+ T lymphocytes [164.3/10 high power f ields (HPF)] and in the tumor itself of CD8+ cells (54.9/10 HPF). Cholangiocarcinomas contained a heterogeneous amount of TIL, composed mainly of CD3+ T cells with a predominance of CD8+ cells in the tumor tissue (52.6/10 HPF) and of CD4+ cells in the interface region (223.1/10 HPF). CD56+ cells of the innate immune system were scarce. There was no significant difference between hepatocellular or cholangiolar carcinoma. No correlation with the clinicopathological data was seen. CONCLUSION: Liver TIL consists of intratumoral CD8+ T cells and peritumoral CD4+ T cells indepen-dent of histogenetic origin. Different functions of lym-phocytes in these regions seem possible.

Fast Sub-Pixel Motion Estimation Algorithm For H.264

A novel fast sub-pixel search algorithm is proposed to accelerate sub-pixel search. Based on the features of predicted motion vector (PMV) and texture direction observed, the proposed method effectively filters out impossible points and thus decreases 11 searched points in average during the sub-pixel search stage. A threshold is also adopted to early terminate the sub-pixel search. Simulation results show that the proposed method can achieve up to 4.8 times faster than full sub-pixel motion search scheme (FSPS) with less than 0.025 dB PSNR losses and 2.2% bit-length increases.

Weighting indicators of building energy efficiency assessment taking account of experts' priority

Analytic hierarchy process(Group AHP) is combined with two different methods of assigning experts' priority to weight indicators in building energy efficiency assessment.One is to assign the experts' priority averagely,and the other is to use cluster analysis to assign experts' priority.The results show that,1) Different expert's priority assigns result in great different weights of indicators in building energy efficiency assessment,therefore,the method of assigning experts' priority should be taken into account carefully while weighting indicators of building energy efficiency assessment using Group AHP;2) Three indicators are found to be overwhelmingly important in residential building energy efficiency assessment in the hot summer and cold winter zone in China.They are 'Outdoor & indoor shadow','Heating & air-conditioning facilities' and 'Insulation of envelope';3) The method combining cluster analysis with Group AHP to weight indicator of building energy efficiency assessment has the advantage of finding overwhelming important indicator,whereas,some less important indicators have a tendency to be ignored.A useful reference is provided for building energy conservation including policy revision and energy efficient residential building design.