2-step lignin-first catalytic fractionation with bifunctional Pd/ß-zeolite catalyst in a flow-through reactor

This work demonstrates an additive and hydrogen-free 2-step lignin-first fractionation in flow-through. First, solvolytic delignification renders lignin liquors with its native chemical structure largely intact; and second, ß-zeolite catalytic depolymerization of these liquors leads to similar monomer yields as the corresponding 1-step fractionation process. Higher delignification temperatures lead to slightly lower ß−O−4 content in the solvated lignin, but does not affect significantly the monomer yield, so a higher temperature was overall preferred as it promotes faster delignification. Deposition of Pd on ß-zeolite resulted in a bifunctional hydrogenation/dehydration catalyst, tested during the catalytic depolymerization of solvated lignin with and without hydrogen addition. Pd/ß-zeolite displays synergistic effects (compared to the Pd/γ-Al2O3 and ß-zeolite tested individually and as a mixed bed), resulting in higher monomer yield. This is likely caused by increased acidity and the proximity between the metallic and acid active sites. Furthermore, different ß-zeolite with varying SAR and textural properties were studied to shed light onto the effect of acidity and porosity in the stabilization of lignin monomers. While some of the catalysts showed stable performance, characterization of the spent catalyst reveals Al leaching (causing acidity loss and changes in textural properties), and some degree of coking and Pd sintering.</p

Inter-observer Agreement in Laryngeal Pre-neoplastic Lesions

In this series, laryngeal preneoplastic lesions were evaluated by the classifications of the World Health Organization (WHOC), Ljubljana (LC) and squamous intraepithelial neoplasia (SINC) by multiple observers. The inter-observer agreement (IA) by WHOC for laryngeal lesions had been previously evaluated, but to the best of our knowledge, there are no data for LC and SINC. H&E stained slides from 42 laryngeal biopsies were evaluated by fourteen participants according to WHOC and LC, and SINC was additionally applied by 6. The results were analyzed statistically. The diagnoses which were favored by most participants for each case, according to WHOC, were as follows: squamous cell hyperplasia (n = 5; 12%), mild dysplasia (n = 11; 26.2%), moderate dysplasia (n = 12; 28.6%), severe dysplasia (n = 7; 16.7%), carcinoma in situ (n = 5; 12%), and invasive squamous cell carcinoma (n = 2; 4.8%). There was a significant difference between the participants for all three classifications; some participants gave lower or higher scores than the others. The mean correlation coefficients (MCC) of the participants were higher for WHOC compared to LC (0.55 ± 0.15 and 0.48 ± 0.14, respectively). The mean linear-weighted kappa (wKappa) values of participants were not significantly different (0.42 ± 0.10, 0.41 ± 0.12 and 0.37 ± 0.07 for WHOC, LC and SINC, respectively). The kappa values in this series are in agreement with those in previous literature for WHOC, and the similar results obtained for LC and SINC are novel findings. Although the MCC of WHOC was higher, as the wkappa was not significantly different, the findings in this series are not in favor of any of the classifications for better IA for pre-neoplastic laryngeal lesions. © 2010 Humana

Interobserver agreement in salivary gland neoplasms by telepathology an analysis of 47 cases

PubMedID: 23700720OBJECTIVE: To assess the discrepancies that prevailed among the members of the Head and Neck Pathology Working Group in Turkey in diagnosing salivary gland tumors, classified primarily according to myoepithelial origin, by utilizing telepathology. STUDY DESIGN: At least 4 representative images were obtained from each case of a total of 47 salivary gland tumors, and these were studied by 14 participants. The tumors examined were classified into 2 categories under behavior as malignant or benign, and also grouped into 2 categories under differentiation: those showing and those not showing myoepithelial differentiation. Representative areas from hematoxylin and eosin-stained slides were imaged by experienced pathologists. Images from the cases were recorded and distributed via compact disc. RESULTS: The participants in this study had a mean of 12.8 years' experience in pathology. The agreement ratios on tumors showing myoepithelial differentiation and malignancy were 86% and 81%, respectively. Basal cell adenocarcinoma gathered the lowest agreement of the myoepithelial differentiation among the tumors by 64%. The highest agreement (100%) was for 17 myoepitheliomas. While adenoid cystic carcinoma attained the highest ratio (95%), myoepithelial carcinoma had the lowest ratio (47%) of agreement on malignancy among the 19 observers. Accordingly, regarding benign tumors the ratio of agreement on the benignancy was 70%, with the highest percentage being 91% for basal cell adenoma. CONCLUSION: Electronic media acting as a usable technological tool for the distribution of pathology expertise may be used to obtain a second opinion about sali-vary gland tumors.© Science Printers and Publishers, Inc