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  • Author: Hai-Feng Liu x
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Mechanical Properties Of 3D-Structure Composites Based On Warp-Knitted Spacer Fabrics

Abstract

In this paper, the mechanical properties (compression and impact behaviours) of three-dimension structure (3D-structure) composites based on warp-knitted spacer fabrics have been thoroughly investigated. In order to discuss the effect of fabric structural parameters on the mechanical performance of composites, six different types of warp-knitted spacer fabrics having different structural parameters (such as outer layer structure, diameter of spacer yarn, spacer yarn inclination angle and thickness) were involved for comparison study. The 3D-structure composites were fabricated based on a flexible polyurethane foam. The produced composites were characterised for compression and impact properties. The findings obtained indicate that the fabric structural parameters have strong influence on the compression and impact responses of 3D-structure composites. Additionally, the impact test carried out on the 3D-structure composites shows that the impact loads do not affect the integrity of composite structure. All the results reveal that the product exhibits promising mechanical performance and its service life can be sustained.

Open access
Establishment of renal failure models by laparoscopy in bama pigs which underwent partial nephrectomy and radical contralateral nephrectomy

Abstract

Introduction

The miniature pig possesses unmatched advantages as an animal model because of its high homology with humans. Our experiment aimed to build a chronic renal failure (CRF) model in pigs via laparoscopy.

Material and Methods

Laparoscopic surgery was performed twice to build a CRF model. The first surgery was a left partial nephrectomy and the second was a right radical nephrectomy. Pigs were grouped by the total renal tissue to be resected: ⅔, ¾ or ⅚. Physiological parameters (rectal temperature and heart rate), haematological parameters (WBC and RBC) and renal function (serum creatinine – CR and blood urea nitrogen – BUN) were measured preoperatively and every week postoperatively.

Results

After renal resection the pigs manifested chronic renal failure. Heart rate and body temperature declined to varying degrees over 12 postoperative weeks. No significant difference was observed between the different groups. The result of renal function tests found that postoperative serum CR and BUN in all groups were continuously elevated, and the level of serum CR at two weeks post procedure differed very significantly from its preoperative value (P < 0.05). BUN was significantly elevated at one week (P < 0.05). The renal function decreased significantly faster in the ⅚ group than in the other two groups. The trend of renal function change was similar among groups, but progress was slower in the ⅔ and ¾ groups.

Conclusion

⅚ kidney resection was the optimal miniature pig model of CRF.

Open access
Treatment of nasopharyngeal carcinoma using simultaneous modulated accelerated radiation therapy via helical tomotherapy: a phase II study

Abstract

Background

The aim of the study was to evaluate short-term safety and efficacy of simultaneous modulated accelerated radiation therapy (SMART) delivered via helical tomotherapy in patients with nasopharyngeal carcinoma (NPC).

Methods

Between August 2011 and September 2013, 132 newly diagnosed NPC patients were enrolled for a prospective phase II study. The prescription doses delivered to the gross tumor volume (pGTVnx) and positive lymph nodes (pGTVnd), the high risk planning target volume (PTV1), and the low risk planning target volume (PTV2), were 67.5 Gy (2.25 Gy/F), 60 Gy (2.0 Gy/F), and 54 Gy (1.8 Gy/F), in 30 fractions, respectively. Acute toxicities were evaluated according to the established RTOG/EORTC criteria. This group of patients was compared with the 190 patients in the retrospective P70 study, who were treated between September 2004 and August 2009 with helical tomotherapy, with a dose of 70-74 Gy/33F/6.5W delivered to pGTVnx and pGTVnd.

Results

The median follow-up was 23.7 (12–38) months. Acute radiation related side-effects were mainly problems graded as 1 or 2. Only a small number of patients suffered from grade 4 leucopenia (4.5%) or thrombocytopenia (2.3%). The local relapse-free survival (LRFS), nodal relapse-free survival (NRFS), local-nodal relapse-free survival (LNRFS), distant metastasis-free survival (DMFS) and overall survival (OS) were 96.7%, 95.5%, 92.2%, 92.7% and 93.2%, at 2 years, respectively, with no significant difference compared with the P70 study.

Conclusions

Smart delivered via the helical tomotherapy technique appears to be associated with an acceptable acute toxicity profile and favorable short-term outcomes for patients with NPC. Long-term toxicities and patient outcomes are under investigation.

Open access