70 research outputs found
Quantum fluctuations around black hole horizons in Bose-Einstein condensates
We study several realistic configurations allowing to realize an acoustic
horizon in the flow of a one dimensional Bose-Einstein condensate. In each case
we give an analytical description of the flow pattern, of the spectrum of
Hawking radiation and of the associated quantum fluctuations. Our calculations
confirm that the non local correlations of the density fluctuations previously
studied in a simplified model provide a clear signature of Hawking radiation
also in realistic configurations. In addition we explain by direct computation
how this non local signal relates to short range modifications of the density
correlations
Photosynthetic pigment levels in Macroptilium lathyroides L under water deficit.
TĂtulo em espanhol: Contenido de pigmentos fotosinteticos Macroptilium lathyroides L en condiciones de sequia
Wheat amylase/trypsin inhibitors (ATIs): occurrence, function and health aspects
Amylase/trypsin inhibitors (ATIs) are widely consumed in cereal-based foods and have been implicated in adverse reactions to wheat exposure, such as respiratory and food allergy, and intestinal responses associated with coeliac disease and non-coeliac wheat sensitivity. ATIs occur in multiple isoforms which differ in the amounts present in different types of wheat (including ancient and modern ones). Measuring ATIs and their isoforms is an analytical challenge as is their isolation for use in studies addressing their potential effects on the human body. ATI isoforms differ in their spectrum of bioactive effects in the human gastrointestinal (GI), which may include enzyme inhibition, inflammation and immune responses and of which much is not known. Similarly, although modifications during food processing (exposure to heat, moisture, salt, acid, fermentation) may affect their structure and activity as shown in vitro, it is important to relate these changes to effects that may present in the GI tract. Finally, much of our knowledge of their potential biological effects is based on studies in vitro and in animal models. Validation by human studies using processed foods as commonly consumed is warranted. We conclude that more detailed understanding of these factors may allow the effects of ATIs on human health to be better understood and when possible, to be ameliorated, for example by innovative food processing. We therefore review in short our current knowledge of these proteins, focusing on features which relate to their biological activity and identifying gaps in our knowledge and research priorities
Successful medical treatment of glans ischemia after voluntary buprenorphine injection
INTRODUCTION: The diverted use of synthetic opioid buprenorphine by drug addicts can be responsible for serious ischemic and infectious complications, particularly in the case of intravenous injection. AIM: We present a case of serious glans ischemia after buprenorphine injection directly into the deep dorsal vein of the penis. Analysis using new medical imaging techniques and treatments is detailed below. METHODS: A 26-year-old male drug addict presented with glans pain 4 days after self-injection of buprenorphine into the deep dorsal vein of the penis. The patient was apyretic and presented a urethral discharge. His glans was blue without discoloration on digital pressure. Additionally, his biologic and serologic tests were normal while bacteriology showed the presence of Enterobacter cloacae urethritis. RESULTS: After 48 hours of intravenous antibiotic treatment without improvement, a specific medical treatment using enoxaparin and ilomedin was initiated, with the assumption that there was an ischemic complication. Laser speckle contrast imaging allowed confirmation of the presence of distal penis ischemia and provided an accurate mapping of the ischemic zone. A 28-day treatment combining antibiotics, subcutaneous heparin at curative dose, antiplatelet drug, ilomedin, and hyperbaric oxygen therapy resulted in clinical improvement of the lesions with no functional complications. CONCLUSIONS: To date, no consensus exists on the proper diagnostic and treatment approach to severe glans ischemia due to buprenorphine injection into the deep dorsal vein of the penis. The results of laser speckle contrast imaging were of real interest during the process of diagnosis. In addition, the combination of ilomedin with hyperbaric oxygen therapy and anticoagulant and antiplatelet drugs appeared to be an effective therapy
Effect of drought stress on proline content and eletrolyte leakage in leaves and roots of forage legumes.
Understanding Hawking radiation from simple models of atomic Bose-Einstein condensates
This chapter is an introduction to the Bogoliubov theory of dilute Bose
condensates as applied to the study of the spontaneous emission of phonons in a
stationary condensate flowing at supersonic speeds. This emission process is a
condensed-matter analog of Hawking radiation from astrophysical black holes but
is derived here from a microscopic quantum theory of the condensate without any
use of the analogy with gravitational systems. To facilitate physical
understanding of the basic concepts, a simple one-dimensional geometry with a
stepwise homogenous flow is considered which allows for a fully analytical
treatment.Comment: 41 pages. to appear in the proceedings of the IX SIGRAV School on
'Analogue Gravity', Como (Italy), May 201
- …