1,721,124 research outputs found
I mercati all'ingrosso del Veneto: problemi e prospettive in vista della revisione del Piano Regionale
No full textmercati ingross
Politiche di marketing delle imprese alberghiere con particolare riferimento agli insediamenti turistici del Lago di Garda
No full textturism
Prevention of hemolysis in blood samples collected from intravenous catheters.
No full textOBJECTIVES: Samples drawn through intravenous catheters are frequently hemolyzed. We planned a prospective, randomized study to establish whether hemolysis in samples drawn from intravenous catheters may be reduced using S-Monovette® tubes collected by manual aspiration as compared with standard vacuum tubes.DESIGN AND METHODS: We studied 52 consecutive patients admitted to the ED. Blood was drawn through a 20-gauge intravenous catheter. A 5.0mL, Becton Dickinson Vacutainer® SST II Plus serum tube was collected and discarded. In the odd group of patients (i.e., n. 1, 3, 5, etc.), a second SST II tube was drawn with vacuum ("BD-V"), followed by a 5.5mL S-Monovette® serum tube collected with manual aspiration ("SD-A") and an identical S-Monovette collected by vacuum ("SD-V"). In the pair group of patients (i.e., n. 2, 4, 6, etc.), the sequence was modified to "SD-A", "SD-V" and "BD-V". Serum was separated and tested for lactate dehydrogenase (LDH), potassium and cell-free hemoglobin.RESULTS: The mean concentration of potassium (+2.7% in BD-V and +1.7% in SD-V, respectively), LDH (+15% in BD-V and +7% in SD-V, respectively) and cell-free hemoglobin was significantly increased when samples were collected with vacuum tubes as compared with manual aspiration. No significant differences were observed between SD-V and BD-V. The frequency of hemolyzed samples was higher when blood was collected with the vacuum as compared with SD-A (i.e., 2%), but did not differ between BD-V and SD-V (i.e., 29 versus 31%; p=0.70).CONCLUSION: S-Monovette can be used with vacuum or aspiration collection. This latter approach allows blood drawing with limited shear stress and less likelihood of generating spuriously hemolysis
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Influence of spurious hemolysis on blood gas analysis.
No full textBackground: Although the prevalence of hemolyzed samples referred for blood gas analysis is as high as 4%, no studies have assessed the bias introduced by spurious erythrocyte breakdown, nor it is known which parameters are mostly influenced and to what extent. This study was hence planned to assess the influence of spurious hemolysis on venous blood gas analysis. Methods: Venous blood was collected from nine healthy volunteers in sodium heparin tubes and divided in two aliquots of 3 mL. The former aliquot was mechanically hemolyzed by aspiration with 0.5 mL insulin syringe equipped with 30 gauge needle. One milliliter of all aliquots was tested for hemoglobin, pH, oxygen partial pressure (pO2), partial pressure of carbon dioxide (pCO2), bicarbonate (HCO3-), oxygen tension at 50% hemoglobin saturation (p50), oxygen saturation (sO2), actual base excess (ABE), carboxyhemoglobin (COHb), methemoglobin (metHb), ionized calcium (Ca2+) and potassium, on ABL800 flex. The remaining 2 mL of blood were centrifuged, plasma separated and tested for hemolysis index. Results: The concentration of cell-free hemoglobin increased from <0.5 g/L to 8.9±1.5 g/L in hemolyzed aliquots. In hemolyzed blood, significant decreases were found for pH (-0.2%), pO2 (-4.9%), sO2 (-4.9%), COHb (-11%) and Ca2+ (-7.0%), whereas significant increases were observed for pCO2 (+4.1%), HCO3- (+1.4%) and potassium (+152%). Clinically meaningful bias was found for pO2, pCO2, Ca2+ and potassium. Conclusions: Spurious hemolysis is likely to introduce meaningful biases in blood gas analysis, hence manufacturers of blood gas analyzers should develop instrumentation capable of identifying interfering substances in whole blood. The presence of spurious hemolysis should also be suspected whenever test results do not reflect the clinics
Ca2+-dependent inactivation of ICaL accounts for the dependence of action potential duration on extracellular Ca2+ in a model of human ventricular myocyte
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