Polyphenylene sulfide (PPS) superfine fiber is a promising high efficient material for high temperature dedusting. In this paper, the PPS superfine fiber was prepared by melt-electrospinning for the first time. In order to produce the finer fibers, the polypropylene (PP) was added to PPS and the effects of blending ratio, spinning voltage, spinning temperature, and spinning distance on resultant fibers were investigated systematically. The superfine fibers of PPS with an average diameter of 4.12 μm were successfully prepared at the optimized condition, which was one third of that by melt-spinning method. With the decrease of 76.21 % fibers diameter, the filter efficiency increased from 87.03 % to 98.05 %. The presented method provides a new way for the scalable and green fabrication of PPS superfine fibers.

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Abstract

Objectives: The goal of this study was to determine the correlation of clinicopathological factors and the up-regulation of Int-8 receptors and vascular endothelial growth factor (VEGF) expression in oral squamous cell carcinoma (OSCC).

Materials and Methods: Clinical data (age, gender, size of the tumor, location of the tumor, lymph nodes status,..) were collected from 20 patients with OSCC, tabulated and statistically analyzed (SPSS17).Immunohistochemical stainings of Int-8 receptors, CXCR1 and CXCR2 (united states biological, United Bio, USA) and VEGF (Abcam, Cambridge, MA, USA) were done.

Results: Our immunohistochemical study demonstrated: 1)expression of Int-8 receptors in all cases of OSCC with variable intensities, 2) high-level staining of VEGF In poorly differentiated and invasive oral squamous cell carcinoma. Significant correlation was observed between immunohistochemical expression of Int-8 receptors, VEGF and histologic differentiation and clinical stages(Analysis of variance ANOVA, P<0.05).

Conclusion: Our findings suggest that the reactivity to Int-8 receptors

observed in OSCC cases could be used as a parameter for tumor aggressiveness and as potential prognostic marker. Also, up-regulation of VEGF may play a role in the angiogenesis and progression of oral squamous cell carcinoma.

This paper focuses on the revision of the literature related to the reading skills as a background and reading for comprehension as the final desirable product of practising reading. This includes an overview of reading theories, reading skills, and reading strategies and the difference between them. The involvement of conjunctions as defined and classified by Halliday and Hasan (1975) in the reading theories, reading skills, and reading strategies will be highlighted. The study offers important pedagogical recommendations for teachers and curriculum designers. Explicit teaching of reading strategies with clear focus on conjunctions may contribute to the development of reading for comprehension and other English language skills.

Key words: reading comprehension, skills, strategies, conjunctions.