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An experimental investigation has been performed to measure average and local mass transfer coefficients on the tip of a gas turbine blade using the naphthalene sublimation technique. The heat/mass transfer analogy can be applied to obtain heat transfer coefficients from the measured mass transfer data. Flow visualization on the tip surface is provided using an oil dot technique. Two different tip geometries are considered: a squealer tip and a winglet-squealer tip having a winglet on the pressure side and a squealer on the suction side of the blade. Measurements have been taken at tip clearance levels ranging from 0.6 to 3.6% of actual chord. The exit Reynolds number based on actual chord is approximately 7.2 X [10.sup.5] for all measurements. Flow visualization shows impingement and recirculation regions on the blade tip surface, providing an interpretation of the mass transfer distributions and offering insight into the fluid dynamics within the gap. For both tip geometries the tip clearance level has a significant effect on the mass transfer distribution. The squealer tip has a higher average mass transfer that sensibly decreases with gap level, whereas a more limited variation with gap level is observed for the average mass transfer from the winglet-squealer tip.

Background. Intradermal therapy (mesotherapy) is a technique used to inject drugs into the surface layer of the skin. The intradermal micro deposit allows to modulate the kinetics of drugs, slowing down its absorption and prolonging the local mechanism of action. This technique is applied in the treatment of some forms of localized pain when a systemic drug-saving effect is useful, when it is necessary to synergize with other pharmacological or non-pharmacological therapies, when other therapies have failed or cannot be used. Aim. The purpose of our study was to evaluate the effect of a mixture with respect to its lower concentration. We also wanted to evaluate the number of sessions needed to reach the therapeutic goal (50% reduction in pain from baseline) in patients with acute or chronic neck pain. Method. We analyzed retrospectively data from 62 patients with cervicobrachial pain treated with intradermal drugs. Group A received a mixture of drugs; group B received half the dose of drugs. Results. Patients who received a lower concentration of drugs achieved similar results to those who received a higher dose. The therapeutic goal was achieved on average with 3.5 + 1.7 sessions on a weekly basis (min 1; max 9). Subjects in group A required 4±1.7 treatments (min 1; max 9), while subjects in group B required 3±1.5 treatments (min 1; max 7). Conclusions. Our study confirms that even a lower dose of drugs can induce a clinically useful result. This study confirms that the useful effect of mesotherapy is only partly due to the pharmacological action. Further randomized prospective studies are needed to standardize the technique in the various pain syndromes, but it is recommended to follow the guidelines of the Italian Society of Mesotherapy to ensure patients receive appropriate treatment. [ABSTRACT FROM AUTHOR]

Introduction. Mesotherapy, also known as local intradermal therapy, widely used all over the world, is a technique used to inject substances into the surface layer of the skin. There are no international guidelines for the correct use of this technique and in many countries, it is still applied empirically without valid patient consent. The Italian society of mesotherapy has planned a study to assess the rationale and clinical applications based on current evidence. Methods. An independent steering committee, based on the available scientific literature, has formulated a series of clinical questions. 21 experts responded by writing an evidence-based document. From this document 30 statements were obtained which were presented to 114 experts using the Delphi method. Results. 28 statements reached a broad agreement on definition, technique, pharmacological rationale, indications and some crucial ethical aspects. Conclusions. Although further studies are needed to establish the clinical role of this technique in each field of application, our statements recommend the correct application according to the needs of the individual patient in full respect of ethics. [ABSTRACT FROM AUTHOR]

The cooling of a finned cylinder with a jet flow is discussed. A higher heat transfer is realized by cooling the finned cylinder with a jet flow as compared to the cooling of a smooth cylinder.

OBJECTIVE: Low back pain (LBP) is a highly prevalent chronic pain condition with a neuropathic component of pain that limits the benefits of classical opioids. Tapentadol is an innovative drug for the treatment of chronic severe pain, with a dual mechanism of action combining μ-opioid receptors agonism and noradrenaline re-uptake inhibition (NRI). Its efficacy is equal to that of strong opioids, with a better tolerability profile and a consequently lower risk of treatment discontinuation. The aim of this study was to evaluate the analgesic efficacy and tolerability of tapentadol prolonged release (PR) vs. other analgesics in patients with moderate-to-severe neuropathic low back pain, before and after back surgery. PATIENTS AND METHODS: The primary endpoints of the study were the rate of response to treatment, measured as ≥30% reduction in pain intensity on the Numeric Rating Scale (NRS), and tapentadol PR efficacy for pain relief. The secondary endpoints were the improvements of the neuropathic component of pain and of sleep quality. RESULTS: A total of 40 patients were enrolled in the study, receiving either tapentadol PR (n=21, 52.5%) or other analgesics (n=19, 47.5%), both before and after surgery. The rate of response to treatment was statistically in favor of tapentadol PR (p<0.01). The reduction in pain intensity was statistically significant in the group treated with tapentadol PR, both before and after surgery (p<0.01), with a complete resolution of pain 90 days after surgery. The quality of sleep after surgery improved more in patients treated with tapentadol PR than in the comparator group (p<0.01), with 100% of the patients reporting a “good” sleep quality 2 months after surgery. CONCLUSIONS: Tapentadol PR was well tolerated by all patients, and its efficacy for pain relief was also confirmed in our small group of “real-life” patients with chronic, severe low back pain. Overall, the tolerability of this treatment may help to improve patients’ quality of life, which is frequently compromised because of pain and its related comorbidities. [ABSTRACT FROM AUTHOR]