Energy transfer and energy level decay processes in Tm3+-doped tellurite glass

The primary excited state decay and energy transfer processes in singly Tm3þ-doped TeO2:ZnO:Bi2O3:GeO2 (TZBG) glass relating to the 3F4 ! 3H6 1.85 lm laser transition have been investigated in detail using time-resolved fluorescence spectroscopy. Selective laser excitation of the 3H4 manifold at 794 nm, the 3H5 manifold at 1220 nm, and 3F4 manifold at 1760 nm has established that the 3H5 manifold is entirely quenched by multiphonon relaxation in tellurite glass. The luminescence from the 3H4 manifold with an emission peak at 1465 nm suffers strong suppression due to cross relaxation that populates the 3F4 level with a near quadratic dependence on the Tm3þ concentration. The 3F4 lifetime becomes longer as the Tm3þ concentration increases due to energy migration and decreases to 2.92 ms when [Tm3þ]¼4 mol. % as a result of quasi-resonant energy transfer to free OH radicals present in the glass at concentrations between 11018 cm3 and 21018 cm3. Judd-Ofelt theory in conjunction with absorption measurements were used to obtain the radiative lifetimes and branching ratios of the energy levels located below 25 000 cm1. The spectroscopic parameters, the cross relaxation and Tm3þ(3F4) ! OH energy transfer rates were used in a numerical model for laser transitions emitting at 2335 nm and 1865 n

Management of perforated diverticulitis with generalized peritonitis. a multidisciplinary review and position paper

La diverticolite perforata è una condizione clinica emergente e la sua gestione è impegnativa e ancora dibattuta. Lo scopo di questo documento di posizione era di rivedere criticamente le prove disponibili sulla gestione della diverticolite perforata e della peritonite generalizzata al fine di fornire suggerimenti basati sull'evidenza per una strategia di gestione. Quattro società scientifiche italiane (SICCR, SICUT, SIRM, AIGO), esperti selezionati che hanno identificato 5 temi clinicamente rilevanti nella gestione della diverticolite perforata con peritonite generalizzata che trarrebbero beneficio da una revisione multidisciplinare. Sono state affrontate le seguenti 5 problematiche: 1) Criteri per decidere tra trattamento conservativo e chirurgico in caso di diverticolite perforata con peritonite; 2) Criteri o sistema di punteggio per scegliere l'opzione chirurgica più appropriata quando è confermata la peritonite diffusa 3); La procedura chirurgica appropriata in pazienti emodinamicamente stabili o stabilizzati con peritonite diffusa; 4) La procedura chirurgica appropriata per i pazienti con peritonite generalizzata e shock settico e 5) Terapia medica ottimale in pazienti con peritonite generalizzata da perforazione diverticolare prima e dopo l'intervento chirurgico. Nella diverticolite perforata la chirurgia è indicata in caso di peritonite diffusa o fallimento della gestione conservativa e la decisione di operare non è basata sulla presenza di aria extraluminale. Se la peritonite diffusa è confermata, la scelta della tecnica chirurgica si basa sui risultati intraoperatori e sulla presenza o il rischio di shock settico grave. Ulteriori fattori prognostici da considerare sono lo squilibrio fisiologico, l'età, le comorbidità e lo stato immunitario. Nei pazienti emodinamicamente stabili, la laparoscopia di emergenza presenta vantaggi rispetto alla chirurgia a cielo aperto. Le opzioni includono resezione e anastomosi, procedura di Hartmann o lavaggio laparoscopico. Nella peritonite generalizzata con shock settico, è preferibile un approccio chirurgico aperto. La resezione non restaurativa e / o la chirurgia per il controllo del danno sembrano essere le uniche opzioni praticabili, a seconda della gravità dell'instabilità emodinamica. La gestione medica multidisciplinare dovrebbe essere applicata con gli obiettivi principali di controllare l'infezione, alleviare il dolore postoperatorio e prevenire e / o trattare ileo postoperatorio. In conclusione, la complessità e la diversità dei pazienti con perforazione diverticolare e peritonite diffusa richiede una strategia personalizzata, che preveda un'accurata classificazione dello squilibrio fisiologico, la stadiazione dell'infezione intra-addominale e la scelta della procedura chirurgica più appropriata.Perforated diverticulitis is an emergent clinical condition and its management is challenging and still debated. The aim of this position paper was to critically review the available evidence on the management of perforated diverticulitis and generalized peritonitis in order to provide evidence-based suggestions for a management strategy. Four Italian scientific societies (SICCR, SICUT, SIRM, AIGO), selected experts who identified 5 clinically relevant topics in the management of perforated diverticulitis with generalized peritonitis that would benefit from a multidisciplinary review. The following 5 issues were tackled: 1) Criteria to decide between conservative and surgical treatment in case of perforated diverticulitis with peritonitis; 2) Criteria or scoring system to choose the most appropriate surgical option when diffuse peritonitis is confirmed 3); The appropriate surgical procedure in hemodynamically stable or stabilized patients with diffuse peritonitis; 4) The appropriate surgical procedure for patients with generalized peritonitis and septic shock and 5) Optimal medical therapy in patients with generalized peritonitis from diverticular perforation before and after surgery. In perforated diverticulitis surgery is indicated in case of diffuse peritonitis or failure of conservative management and the decision to operate is not based on the presence of extraluminal air. If diffuse peritonitis is confirmed the choice of surgical technique is based on intraoperative findings and the presence or risk of severe septic shock. Further prognostic factors to consider are physiological derangement, age, comorbidities, and immune status. In hemodynamically stable patients, emergency laparoscopy has benefits over open surgery. Options include resection and anastomosis, Hartmann’s procedure or laparoscopic lavage. In generalized peritonitis with septic shock, an open surgical approach is preferred. Non-restorative resection and/or damage control surgery appear to be the only viable options, depending on the severity of hemodynamic instability. Multidisciplinary medical management should be applied with the main aims of controlling infection, relieving postoperative pain and preventing and/or treating postoperative ileus. In conclusion, the complexity and diversity of patients with diverticular perforation and diffuse peritonitis requires a personalized strategy, involving a thorough classification of physiological derangement, staging of intra-abdominal infection and choice of the most appropriate surgical procedure

Control of enteric neuromuscular functions by purinergic P2X7 receptors in normal rat distal colon and experimental bowel inflammation

Introduction: Purinergic signalling plays a pivotal role in the physiological regulation of several enteric functions, as well as in the modulation of immune/inflammatory cell activity. Recent evidence has shown an active involvement of the purinergic P2X7 receptor (P2X7R) in the fine tuning of immune functions, as well as its critical role in driving enteric neuron apoptosis under intestinal inflammation. However, the participation of this receptor pathway in the regulation of enteric neuromuscular functions remains undetermined. Aims: This study investigated the role of P2X7Rs in the control of colonic motility, both under normal conditions and in the presence of experimental colitis. Methods: Colitis was induced by intrarectal administration of 2,4-dinitrobenzenesulfonic acid (DNBS) in adult male Sprague-Dawley rats. Six days after colitis induction, colonic longitudinal muscle strips (LMS), obtained from normal or inflamed rats, were suspended in organ baths, containing Krebs solution additioned with NK 1, 2 and 3 receptor antagonists, and connected to isometric transducers to record atropine-sensitive cholinergic motor activity. The effects of A804598 (selective P2X7R antagonist; 0.001-100 μM) and BzATP (selective P2X7R agonist; 0.001-10 μM) were tested on contractions evoked by electrical stimulation (ES: 0.5 ms, 28 V, 10 Hz), delivered as single train (sES) or repeated every 60 s (rES), or by carbachol (1 μM) in the presence of tetrodotoxin. Results: In normal LMS, A804598 induced a negligible enhancing effect on sES-induced contractions (+7.8±3.5% at 0.1 μM), while a significant increase in the contractile responses elicited by sES was recorded in LMS from inflamed animals (+42.5±3.9% at 0.1 μM). Incubation of LMS with the adrenergic blocker guanethidine (10 μM) did not affect the enhancing effect exerted by A804598 in the presence of colitis. Upon incubation with Nw-propyl-L-arginine (NPA, inhibitor of neuronal nitric oxide synthase), which per se increased the sES-induced contractions in both normal and inflamed LMS preparations (+15.1±5.5% in normal and +143.5±9.5% in inflamed animals), the A804598 effects were lost. The pharmacological activation of P2X7Rs with BzATP did not significantly affect the contractions to rES in normal LMS (Emax= -10.2±1.9%), while a marked reduction was recorded in LMS from animals with colitis (Emax= -30.5±2.2%). The inhibitory effect of BzATP was antagonized by A804598, and it was also markedly blunted by NPA. Both P2X7R ligands did not affect carbachol-induced contractions. Conclusions: The purinergic system contributes to functional neuromuscular changes associated with bowel inflammation through the involvement of P2X7Rs, which modulate the activity of excitatory cholinergic nerves via a facilitatory control on inhibitory nitrergic pathways

A case report on a patient suffering from recurrent vomiting episodes, whose condition improved markedly during pregnancy and breast feeding

BACKGROUND: The normal physiology of the gastrointestinal tract has been only cursorily examined. Consequently, the pathophysiology of disturbances of the gastrointestinal functions is poorly known. Recurrent vomiting is one of many functional conditions for which it is difficult to find an explanation and to treat. In the following a case is described of a patient presenting with recurrent vomiting episodes, whose condition improved spontaneously during pregnancy and breast feeding. CASE PRESENTATION: A woman with recurrent vomiting episodes over several years was examined by esophagogastroduodenoscopy. This showed a non-peristaltic ventricle. Treatment with the procinetic drug cisapride (Prepulsid(®)) improved the peristalsis and reduced the symptoms. During pregnancy and breast feeding, she was free of symptoms, in spite of having discontinued her medication with cisapride (Prepulsid(®)). CONCLUSION: The fact that the patient improved during pregnancy and breast feeding, would seem to indicate the involvement of factors in the physiology of pregnancy and breast feeding that are of importance for gastric motility. This deserves further investigation

Thermal stability and spectroscopic properties of erbium-doped niobic-tungsten-tellurite glasses for laser and amplifier devices

Er3+ doped niobic-tungsten-tellurite glasses doped with concentration of Er3+ ion up to 3 wt% were fabricated. The effect of Er3+ doping concentration on thermal stability and optical properties was investigated in order to obtain the most suitable rare earth content for developing 1.5 micron compact fiber amplifier pumped with a commercial telecom 980 nm laser diode. The maximum doping concentration allowed was found to be around 1.77 x 10^20 ions/cm^3, for which a broad 1.5 micron emission spectra of 65 nm FWHM and a lifetime of 3.4 ms for the 4I13/2 level was measure

Barrett's esophagus: proton pump inhibitors and chemoprevention II.

The following on proton pump inhibitors (PPIs) and chemoprevention in relation to Barrett's esophagus includes commentaries on 48-h pH monitoring, pH-impedence, bile acid testing, dyspepsia, long/short segment Barrett's esophagus, nonerosive reflux disease (NERD), functional heartburn, dual-release delivery PPIs, immediate-release PPIs, long-term PPI use, prokinetic agents, obesity, baclofen, nocturnal acid breakthrough, nonsteroidal anti-inflammatory drugs (NSAIDs), and new PPIs

Randomised clinical trial: mucosal protection combined with acid suppression in the treatment of non-erosive reflux disease - efficacy of Esoxx, a hyaluronic acid-chondroitin sulphate based bioadhesive formulation

BACKGROUND: Several studies have shown that patients with non-erosive reflux disease (NERD) are less responsive to proton pump inhibitors (PPIs) than those with erosive disease as they belong to different subgroups, in whom factors other than acid can trigger symptoms. AIM: To evaluate whether combined therapy (mucosal protection plus acid suppression) would improve symptom relief compared to PPI treatment alone. METHODS: In a multicenter, randomised, double-blind trial, 154 patients with NERD were randomised to receive Esoxx (Alfa Wassermann, Bologna, Italy), a hyaluronic acid-chondroitin sulphate based bioadhesive formulation, or placebo, in addition to acid suppression with standard dose PPIs for 2 weeks. Symptoms (heartburn, acid regurgitation, retrosternal pain and acid taste in the mouth) and health-related quality of life (HRQL) were evaluated before and after treatment. The primary endpoint was the proportion of patients with at least a 3-point reduction in the total symptom score. RESULTS: At the end of treatment, the primary endpoint was reached by 52.6% of patients taking Esoxx compared to 32.1% of those given placebo (P < 0.01). The same was true also for HRQL, evaluated by means of the Short Form-36 questionnaire, which improved with both treatments, but some items were significantly better after Esoxx plus PPI therapy. CONCLUSION: The synergistic effect of Essox with PPI treatment suggests that mucosal protection added to acid suppression could improve symptoms and HRQL in NERD patients

Integrating data types to estimate spatial patterns of avian migration across the Western Hemisphere

For many avian species, spatial migration patterns remain largely undescribed, especially across hemispheric extents. Recent advancements in tracking technologies and high-resolution species distribution models (i.e., eBird Status and Trends products) provide new insights into migratory bird movements and offer a promising opportunity for integrating independent data sources to describe avian migration. Here, we present a three-stage modeling framework for estimating spatial patterns of avian migration. First, we integrate tracking and band re-encounter data to quantify migratory connectivity, defined as the relative proportions of individuals migrating between breeding and nonbreeding regions. Next, we use estimated connectivity proportions along with eBird occurrence probabilities to produce probabilistic least-cost path (LCP) indices. In a final step, we use generalized additive mixed models (GAMMs) both to evaluate the ability of LCP indices to accurately predict (i.e., as a covariate) observed locations derived from tracking and band re-encounter data sets versus pseudo-absence locations during migratory periods and to create a fully integrated (i.e., eBird occurrence, LCP, and tracking/band re-encounter data) spatial prediction index for mapping species-specific seasonal migrations. To illustrate this approach, we apply this framework to describe seasonal migrations of 12 bird species across the Western Hemisphere during pre- and postbreeding migratory periods (i.e., spring and fall, respectively). We found that including LCP indices with eBird occurrence in GAMMs generally improved the ability to accurately predict observed migratory locations compared to models with eBird occurrence alone. Using three performance metrics, the eBird + LCP model demonstrated equivalent or superior fit relative to the eBird-only model for 22 of 24 species–season GAMMs. In particular, the integrated index filled in spatial gaps for species with over-water movements and those that migrated over land where there were few eBird sightings and, thus, low predictive ability of eBird occurrence probabilities (e.g., Amazonian rainforest in South America). This methodology of combining individual-based seasonal movement data with temporally dynamic species distribution models provides a comprehensive approach to integrating multiple data types to describe broad-scale spatial patterns of animal movement. Further development and customization of this approach will continue to advance knowledge about the full annual cycle and conservation of migratory birds