Thermoacoustic effects in supercritical fluids near the critical point: Resonance, piston effect, and acoustic emission and reflection

We present a general theory of thermoacoustic phenomena in supercritical fluids near the critical point in a one-dimensional cell. We take into account the effects of the heat conduction in the boundary walls and the bulk viscosity near the critical point. We introduce a coefficient $Z(\omega)$ characterizing reflection of sound with frequency $\omega$ at the boundary. As applications, we examine the acoustic eigenmodes in the cell, the response to time-dependent perturbations, sound emission and reflection at the boundary. Resonance and rapid adiabatic changes are noteworthy. In these processes, the role of the thermal diffusion layers is enhanced near the critical point because of the strong critical divergence of the thermal expansion.Comment: 15 pages, 7 figure

Curative and organ-preserving treatment with intra-arterial carboplatin induction followed by surgery and/or radiotherapy for advanced head and neck cancer: single-center five-year results

BACKGROUND: This study evaluated the feasibility, toxicity, response rate and survival of neoadjuvant superselective intra-arterial infusion of high dose carboplatin in advanced head and neck cancer. METHODS: Forty-six patients with primary head and neck squamous cell carcinoma received 3 cycles of intra-arterial carboplatin (300 to 350 mg/m(2 )per cycle every 2 weeks), followed by radiotherapy or surgery plus radiotherapy. RESULTS: No complications or severe toxicity occurred. Sixteen patients (35%) were complete responders, 20 (43%) partial responders while 10 (22%) did not respond to treatment. After completion of the multimodality treatment, 38/46 patients (83%) were complete responders. After a 5-year follow-up period, 18/46 patients (39%) are alive and disease-free, 3 (6,5%) have died of a second primary tumor and 25 (54,5%) have died of the disease. CONCLUSION: Intra-arterial carboplatin induction chemotherapy is a safe, well-tolerated technique that discriminates between responders and non-responders and so may have prognostic significance in planning further integrated treatments aimed to organ preservation for advanced head and neck carcinomas

Tecniche cromatografiche

Le tecniche cromatografiche e, pi\uf9 in generale, le strategie di analisi separative permettono ad un moderno laboratorio di analisi o di controllo di qualit\ue0, di coprire un ampio spettro di attivit\ue0 che vanno dal campionamento (con le tecniche SPE, Solid Phase Extraction 2e SPME, Solid Phase Micro Extraction) al trattamento del campione, fino alla determinazione qualitativa e quantitativa di ultra-tracce di analiti