3,514 research outputs found

    The role of weak interactions in dynamic ejecta from binary neutron star mergers

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    Weak reactions are critical for the neutron richness of the matter dynamically ejected after the merger of two neutron stars. The neutron richness, defined by the electron fraction (Ye), determines which heavy elements are produced by the r-process and thus directly impacts the kilonova light curve. In this work, we have performed a systematic and detailed post-processing study of the impact of weak reactions on the distribution of the electron fraction and of the entropy on the dynamic ejecta obtained from an equal mass neutron star binary merger simulated in full general relativity and with microscopic equation of state. Previous investigations indicated that shocks increase Ye, however our results show that shocks can also decrease Ye, depending on their thermodynamical conditions. Moreover, we have found that neutrino absorption are key and need to be considered in future simulations. We also demonstrated that the angular dependence of the neutrino luminosity and the spatial distribution of the ejecta can lead to significant difference in the electron fraction distribution. In addition to the detailed study of the Ye evolution and its dependences, we have performed nucleosynthesis calculations. They clearly point to the necessity of improving the neutrino treatment in current simulations to be able to predict the contribution of neutron star mergers to the chemical history of the universe and to reliable calculate their kilonova light curves

    Diagnostic evaluation of a point-of-care test for culture and microbial susceptibility testing in canine dermatological infections in clinical practice

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    Background and Aim: Empirical antimicrobial therapy is frequently given in superficial bacterial folliculitis (SBF) and otitis externa (OE) in dogs, especially for the initial clinical presentation. Culture and subsequent antimicrobial susceptibility testing (AST) are generally limited to chronic cases with poor response to initial therapy. Several factors contribute to the failure to implement the use of AST in veterinary practice, i.e., long laboratory turnaround time or special requirements for sample shipping. Point-of-care (PoC) testing might reduce laboratory turnaround time and costs and the risk of emergence of multidrug-resistant pathogens. This study evaluated the Speed Biogram\u2122 PoC test in canine SBF and OE compared with conventional methods for culture and AST. Materials and Methods: Thirty-four canine samples were analyzed: eleven from SBF, seven from bacterial OE, four from mixed OE, six from Malassezia spp. OE, and six negative controls. Sensitivity (Se) and specificity (Sp) of the PoC test and the agreement between the PoC test and conventional methods were evaluated. Results: Se and Sp of PoC test in discriminating between healthy and unhealthy subjects were 100% (95% confidence interval [CI] 87.66-100.00) and 100% (95% CI 54.1-100.0), respectively. For bacterial identification, the k value was 0.532. Se and Sp of PoC tests for AST were 81.73% (95% CI 72.95-88.63) and 93.10% (95% CI 88.86-96.98), respectively with a total good agreement between tests (mean k=0.714), but major (8/27) and very major (19/27) errors were observed in 55% of bacterial conventional culture-positive samples. Conclusion: PoC test can identify dogs with SBF and OE, but AST is not sufficiently accurate. The lack of susceptibility testing for methicillin makes this test inappropriate for use in small animal practice

    Refractive index inhomogeneity within an aerogel block

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    Evaluating local inhomogeneities of the refractive index inside aerogel blocks to be used as Cherenkov radiator is important for a high energy physics experiment where angular resolution is crucial. Two approaches are described and compared. The first one is based on the bending of a laser beam induced by refractive index gradients along directions normal to the unperturbed optical path. The second method exploits the Cherenkov effect itself by shooting an ultra-relativistic collimated electron beam through different points of the aerogel surface. Local refractive index variations result in sizable differences in the Cherenkov photons distribution. © 2005 Elsevier B.V. All rights reserved

    Evaluation of Feline Packed Red Blood Cell Units Obtained by Blood Sedimentation and Stored for 42 Days for Transfusion Purposes

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    Component therapy involves separation of whole blood (WB) into its components (packed red blood cells\u2014PRBCs\u2014and plasma), for specific replacement therapy and to reduce transfusion reactions. In cats, blood for transfusion is commonly collected using an open system and administered as WB, in part because of the challenge of preparing components from a small blood volume. Feline blood has a high erythrocyte sedimentation rate; therefore, if the syringe containing collected blood is placed upright, plasma can be removed from the red cells shortly after collection for separate storage of plasma and PRBCs. The aim of this study was to assess the characteristics of feline PRBC units obtained by blood sedimentation both at collection and after storage for 42 days. Blood was collected from fourteen feline blood donors into three 20-ml syringes pre-charged with CPDA-1:blood ratio of 1:7 using an open system. A pre-donation CBC was performed in each donor. The three syringes were allowed to sediment for approx. 1 hour at room temperature. Then plasma was aseptically expressed into plain transfer bags and RBC expressed into another transfer bag pre-charged with 10 ml of SAG-M. PRBCs units were stored in a blood-dedicated refrigerator and sampled using blood bag segments at preparation time (D0) and after 42 days storage (D42). On pre-donation blood and on PRBC units at D0 and D42 the following parameters were evaluated: I) hematological parameters (RBC, Hb, Hct, WBC, PLT); II) percentage hemolysis; III) morphological index (only for PRBC units), scored of 0 to 3 based on echinocyte transformation of the normal discocyte; IV) aerobic and anaerobic blood culture (only for PRBC units). From donor to PRBC units there was a significant increase in RBC count (mean increase +1886\ub1SD1399 \u3bcL/103), Hb concentration (+2.8\ub12.2 g/dl), Hct percentage (+8.3\ub15.5%). Significant reduction was found in PLT count (-249\ub1189 \u3bcL/103). Comparing PRBC at D0 and D42 a significant increase was found in percentage hemolysis (+1.2%), morphological index (+0.9) and a significant reduction in RBC count (-460\ub1679 \u3bcL/103), Hct percentage (-3.2\ub13.5%), WBC count (median -2589 \u3bcL/103), and PLT count (median -43 \u3bcL/10). All blood cultures were negative for bacterial growth. PRBC units obtained by sedimentation of donated blood appear to be a suitable blood component for treatment of normovolemic anemia. However, storage for 42 days, as suggested for canine and feline PRBC units, resulted in significant hematological changes that could reduce oxygen delivery after transfusion

    Evaluation of feline red blood cells collected with an open system and stored for 35 days as whole blood units

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    Introduction: The increasing access to veterinary hospital blood banks and commercial sources of feline blood products means that transfusion therapy is more widely available to veterinarians and feline stored blood products are used more often. Despite the increasing availability of feline blood collected and stored for transfusion purposes, few studies have investigated storage lesions in feline whole blood (FWB) units and no study has evaluated hematological changes in FWB units. The objective of this study was to assess changes in feline RBCs collected and stored for transfusion purposes as FWB units. Methods:A prospective, laboratory invitrostudy wasconducted. Twelve nonleukoreduced FWB units were collected with an open system using three 20-mL syringes prefilled with citrate, phos- phate, dextrose, and adenine (CPDA-1) preservative-anticoagulant solution with ratio with blood of 1:7 from anesthetized feline blood donors. Units were stored in a blood bank dedicated refrigerator and sampled every 7 days (D7, D14, D21, D28) from collection (D0) to the end of storage (35 days, D35). At each time point, the following were evaluated: (1) hematological parameters (RBC, HGB, HCT, MCV, MCH, MCHC, RDW); (2) percentage of hemolysis; (3) morphological index, scored of 0 to 4 based on echinocyte transformation of the normal discocyte; and (4) aerobic and anaerobic blood culture. Results were statistically compared to D0, with t-test or Wilcoxon test, as appropriate with statistical significance set at P < 0.01. Results: There was no significant difference in hematological parameters at any time point with respect to D0. Significant increases were found in percentage of hemolysis and morphological index starting from 21 days of storage (P = 0.0002 and P = 0.0039, respectively). Mean hemolysis percentage value was less than 1% up to 21 days of storage. All blood cultures were negative for bacterial growth. Conclusion: RBCs in FWB units collected with an open system can undergo some significant hematological changes, but these results suggest that storage for up to 21 days is safe. In vivo studies are required to establish if these changes affect the ability of stored RBCs to circulate and provide adequate oxygen delivery after transfusion

    Hematological, biochemical and microbiological evaluation of feline whole blood units collected using an open system and stored for 35 days

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    Despite the increasing availability of feline blood, which is collected and stored for transfusion purposes, few studies have assessed the effect of storage on feline whole blood (WB) units. The purpose of this study was to investigate selected hematologic and biochemical changes during storage of feline WB units and to determine when they occurred. Data from a quality control program for WB units was used in this study. Twelve feline WB units, collected using an open system, were sampled every 7 days from the point of collection to the end of storage at 35 days (D0, D7, D14, D21, D28, and D35). Measurements at each time point were: (1) hematologic parameters; (2) percentage hemolysis; (3) morphologic index scored at 0\u20133, based on echinocyte transformation of the erythrocytes; and (4) selected biochemical parameters. Aerobic and anaerobic culture was performed at D0 and D35. Results were compared statistically to D0 (statistical significance set at <0.01). Storage did not result in statistically significant changes in measured hematological parameters. There were statistically significant increases in percentage hemolysis and morphologic index, starting from D21 (P = 0.000 and P = 0.004, respectively). Glucose decreased significantly from D21 (P = 0.003); potassium increased significantly from D7 (P=0.001); and sodium increased significantly, starting from D28 (P = 0.009). Bacteria were not isolated. Blood in feline WB units collected using an open system underwent some significant storage changes that were time-dependent. As these changes could affect the quality and the utility of stored WB used in feline transfusion medicine, further study is required to determine their clinical importance

    Long-term Intrinsic Rhythm Evaluation in Dogs with Atrioventricular Block

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    Background: Atrioventricular block (AVB) is a conduction abnormality along the atrioventricular node that, depending on etiology, may lead to different outcomes. Objectives: To evaluate variations of intrinsic rhythm (IR) in dogs that underwent pacemaker implantation (PMI). Animals: Medical records of 92 dogs affected by 3rd degree atrioventricular block (3AVB), advanced 2nd degree AVB (2AVB), paroxysmal 3AVB, 2:1 2AVB, or 3AVB with atrial fibrillation (AF) were retrospectively reviewed. Method: The patient IR was documented with telemetry on the day of 1 - (95% CI, 1-2), 33 - (95% CI, 28-35), 105 - (95%CI, 98-156), and 275 days (95%CI, 221-380) after PMI. According to AVB grade at different examinations, AVB was defined as progressed, regressed, or unchanged. Results: In 48 dogs, 3AVB remained unchanged, whereas in 7 it regressed. Eight cases of 2AVB progressed, 3 regressed and 2 remained unchanged. Eight cases of paroxysmal 3AVB progressed and 3 remained unchanged. Four dogs affected by 2:1 2AVB progressed, 2 regressed, and 1 remained unchanged. All cases with 3AVB with AF remained unchanged. Regression occurred within 30 days after PMI, whereas progression was documented at any time. Variations in IR were associated with type of AVB (P <03) and time of follow-up (P <0001). Conclusions and clinical importance: The degree of AVB assessed at the time of PMI should not be considered definitive because more than one-third of the cases in this study either progressed or regressed. Additional studies would be necessary to elucidate possible causes for transient AVB in dogs

    Grape by-products: extraction of polyphenolic compounds using supercritical CO2 and liquid organic solvent - a preliminary investigation.

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    This research focussed on the exploitation of grape by-products as a source of polyphenolic compounds, which are of interest to the food, pharmaceutical and cosmetic industries. In particular, two substrates were tested: Pinot Noir grape skins and grape seeds. Pinot Noir grape skins were extracted by supercritical CO2 added with ethanol as modifier at constant temperature (45 °C) and at variable pressure (200, 300, 400 or 500 bar). The supercritical extraction kinetics of polyphenolic compounds was obtained. Grape seeds were extracted by combining supercritical (at 40 °C and 500 bar and using CO2 or CO2 added with ethanol as modifier) with liquid ethanol extraction. The supercritical technique seemed not to be really effective in extracting polyphenolic compounds; it can be anyway utilized to selectively extract grape seed oil by avoiding any solvent contamination of the matrix which can be further extracted for the recovery of polyphenolic compounds by means of liquid organic solvent

    The Use of Antimalarial Drugs against Viral Infection

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    In recent decades, drugs used to treat malaria infection have been shown to be beneficial for many other diseases, including viral infections. In particular, they have received special attention due to the lack of effective antiviral drugs against new emerging viruses (i.e., HIV, dengue virus, chikungunya virus, Ebola virus, etc.) or against classic infections due to drug-resistant viral strains (i.e., human cytomegalovirus). Here, we reviewed the in vitro/in vivo and clinical studies conducted to evaluate the antiviral activities of four classes of antimalarial drugs: Artemisinin derivatives, aryl-aminoalcohols, aminoquinolines, and antimicrobial drugs

    Texture profile and sensory acceptance of a symbiotic diet aerated mousse containing Lactobacillus acidophilus LA-5, inulin, and fructooligosaccharide

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    This work dealt with the texture profile and sensory acceptance of a symbiotic diet aerated mousse containing Lactobacillus acidophilus LA-5, inulin, and fructooligosaccharid
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