45 research outputs found
The phonon theory of liquid thermodynamics
Heat capacity of matter is considered to be its most important property
because it holds information about system's degrees of freedom as well as the
regime in which the system operates, classical or quantum. Heat capacity is
well understood in gases and solids but not in the third state of matter,
liquids, and is not discussed in physics textbooks as a result. The perceived
difficulty is that interactions in a liquid are both strong and
system-specific, implying that the energy strongly depends on the liquid type
and that, therefore, liquid energy can not be calculated in general form. Here,
we develop a phonon theory of liquids where this problem is avoided. The theory
covers both classical and quantum regimes. We demonstrate good agreement of
calculated and experimental heat capacity of 21 liquids, including noble,
metallic, molecular and hydrogen-bonded network liquids in a wide range of
temperature and pressure.Comment: 7 pages, 4 figure
Bronchogenic cyst associated with pericardial defect: Case report and review of the literature
Partial defect of the pericardium combined with bronchogenic cyst is a very rare congenital anomaly. We describe the case of a 32-year-old man with a partial defect of the left pericardium and a bronchogenic cyst arising from the border of the pericardial defect. The cyst was successfully resected with the harmonic scalpel by three-port videothoracoscopic approach
Italian guidelines for primary headaches: 2012 revised version
The first edition of the Italian diagnostic and therapeutic guidelines for primary headaches in adults was published in J Headache Pain 2(Suppl. 1):105–190 (2001). Ten years later, the guideline committee of the Italian Society for the Study of Headaches (SISC) decided it was time to update therapeutic guidelines. A literature search was carried out on Medline database, and all articles on primary headache treatments in English, German, French and Italian published from February 2001 to December 2011 were taken into account. Only randomized controlled trials (RCT) and meta-analyses were analysed for each drug. If RCT were lacking, open studies and case series were also examined. According to the previous edition, four levels of recommendation were defined on the basis of levels of evidence, scientific strength of evidence and clinical effectiveness. Recommendations for symptomatic and prophylactic treatment of migraine and cluster headache were therefore revised with respect to previous 2001 guidelines and a section was dedicated to non-pharmacological treatment. This article reports a summary of the revised version published in extenso in an Italian version
Is there a role for antacids in the modern management of peptic ulcers?
Antacids have been a very useful and effective class of drugs for the treatment of peptic ulcers for over a century, but have been overlooked in recent years. They are effective, safe and economical. In 13 randomised, controlled trials with endoscopic evidence of healing as the end-point, antacids heal 74% of duodenal ulcers in 4 weeks. The evidence for their efficacy in healing gastric ulcers is less strong. For maximal efficacy, adequate doses (e.g., an acid neutralising capacity > 400 mmol/day) need to be taken not intermittently but regularly, several times a day after meals. This regimen may lead to problems with compliance. Tablet forms are more convenient and are as effective as liquid forms. Liquid antacid is of proven value in the prophylaxis of stress ulcer bleeding. Certain antacids may be cytoprotective and more basic research is needed in this area. At the same time, the inclusion of antacids in therapeutic regimens for the healing and prevention of peptic ulcers, and for symptomatic relief during and after eradication of Helicobacter pylori should be explored. Due to their low production costs, antacids have a definite role in developing countries.link_to_subscribed_fulltex