ABSTRACT
The existing studies indicate polymers will present obviously different properties in tension and compression (bimodular effect) which is generally ignored because of the complexity of the analysis. In this study, a functionally graded piezoelectric cantilever beam with bimodular effect was investigated via analytical and numerical methods, respectively, in which a one-dimensional theoretical solution was derived by neglecting some unimportant factors and a two-dimensional numerical simulation was performed based on the model of tension-compression subarea. A full comparison was made to show the rationality of one-dimensional theoretical solution and two-dimensional numerical simulation. The result indicates that the layered model of tension-compression subarea also makes it possible to use numerical technique to simulate the problem of functionally graded piezoelectric cantilever beam with bimodular effect. Besides, the modulus of elasticity E* and the bending stiffness D* proposed in the one-dimensional problem may succinctly describe the piezoelectric effect on the classical mechanical problem without electromechanical coupling, which shows the advantages of one-dimensional solution in engineering applications, especially in the analysis and design of energy harvesting/sensing/actuating devices made of piezoelectric polymers whose bimodular effect is relatively obvious.
ABSTRACT
<p><b>OBJECTIVE</b>To study the clinical characteristics, pathological features, diagnosis, therapy and prognosis of primary small cell carcinoma of the larynx (PSCCL).</p><p><b>METHODS</b>Six cases of PSCCL collected from 1990 to 2009 was retrospectively analyzed. The diagnosis was confirmed by pathological examination. Among six patients, one case belonged to stage III, and the others were in stage IVA. One case abandoned treatment; one case received chemotherapy; one case underwent supraglottic hemilaryngectomy and adjuvant chemoradiotherapy; one case underwent induction chemotherapy, radiotherapy and consolidation chemotherapy. Two cases received induction chemotherapy, concurrent chemoradiation and consolidation chemotherapy. The drug regimens included bleomycin, fluorouracil, cisplatin, etoposide and taxel for 3-6 cycles. The radiotherapy technique included conventional radiotherapy, CT-Sim and three dimensional conformal radiation therapy with (60)Co or 4 MV X-ray for 60 - 66 Gy during 6 - 7 weeks.</p><p><b>RESULTS</b>The time of follow-up was 3 - 24 months and the median was 13 months. Two patients applied with concurrent chemoradiation were alive without tumor. The patient abandoning therapy died of respiratory failure, and the others died of lung or liver metastasis after 8 - 12 months.</p><p><b>CONCLUSIONS</b>PSCCL is a disseminated disease, so the pretreatment evaluation is necessary. Concurrent chemoradiation is an ideal treatment model for this disease.</p>
