169,744 research outputs found
Experimental and Physico-Chemical Comparison of ZnO Nanoparticles’ Activity for Photocatalytic Applications in Wastewater Treatment
No full textIn this contribution, the photoactivity upon activation by simulated sunlight of zinc oxide (ZnO) obtained from two different synthetic pathways (Acetate and Nitrate) is investigated for water purification. Different reagents and processes were exploited to obtain ZnO nanoparticles. Products have been characterized by means of X-Ray Diffraction, Scanning Electron Microscopy along with Energy Dispersive Spectrometer, Dynamic Light Scattering, and Diffuse Reflectance Measurements, to highlight the different outcomes ascribable to each synthesis. A comparison of characteristics and performances was also carried out with respect to commercial ZnO. Nanoparticles of this semiconductor can be obtained as aggregates with different degrees of purity, porosity, and shape, and their physical-chemical properties have been addressed to the specific use in wastewater treatment, testing their effectiveness on the photocatalytic degradation of methylene blue (MB) as a model pollutant. Excluding the commercial sample, experimental results evidenced a better photocatalytic behavior for the ZnO Nitrate sample annealed at 500 °C, which was found to be pure and stable in water, suggesting that ZnO could be effectively exploited as a heterogeneous photocatalyst for the degradation of emerging pollutants in water, provided that thermal treatment is included in the synthetic process
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe 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
The diagnosis of Isospora oocystis in piglets: a comparison of three coprological methods
No full text
The diagnosis of Isospora oocysts in piglets: a comparison of three coprological methods
No full textAims and methods - Copromicroscopic examination carried out by sedimentation and flotation in a hypersaturated NaCl solution, with or without the addition of sugar, is commonly used to diagnose coccidian oocysts in swine. It has recently been pointed out that it would be preferable to use methods based on the elimination of the fatty matter, which is abundantly present in the faeces of piglets, for detecting these oocysts. The employment of suitable copromicroscopic methods would allow the investigator to identify the presence of oocysts even in farms where parasitosis occurs in a sub-clinical way. To identify the best copromicroscopic technique, a total of 155 faecal samples from unweaned piglets (4-27 days old) from 13 Sardinian farms were examined for coccidia with 3 different methods. The following coprological methods were carried out in parallel: (1) sedimentation and flotation in a hypersaturated NaCl solution (SA); (2) sedimentation and flotation in a hypersaturated NaCl solution, with the addition of 500 g of glucose per litre (SU) (Henriksen SA, Christensen JPB, 1992, Vet Rec, 131: 443-444); (3) Ridley-Allen concentration in ethyl acetate and formaldehyde (ET) (Gualdi et al, 2003, Atti SIPAS, 29: 543-554). The samples were also examined using McMaster counting technique, in order to determine the number of oocysts per gram (OPG; cut-off: 50 oocysts) and to compare the above mentioned solutions. The Wilcoxon Signed-Rank Test and the Friedman Test were used for the comparison of 2 and 3 solutions, respectively (Siegel S, Castellan NJ, 1992, Statistica non parametrica, 2^ ed, McGraw-Hill Libri Italia, Milano). Pooled positive faecal samples were used for sporulation and identification of the oocysts.
Results and conclusions - Out of 155 samples, 98 (63.2%), 53 (34.2%) and 30 (19.4%) were positive for coccidian oocysts at ET, SU and SA, respectively. The species identified was Isospora suis. The ET method revealed the highest number of positive samples. The comparison of the results of SU and SA to those of ET was the following : VEDERE ALLEGATO.
The SU and SA positivities were statistically lower with respect to those of ET, which seems to be the most accurate diagnostic method. Oocysts detection was also easier with ET, owing to a smaller presence of faecal debris on the slide. At McMaster counting tecnique, 49 samples were positive at the same time to ET and SU, 19 to ET and SA, and 19 to ET, SU and SA. The number of OPG found with ET (min. 50 – max. 803.400) was statistically higher when compared to those found with SU (z = -3.688) and SA (z = -3.823) (P<0.001). SU showed a higher OPG number with respect to SA (z = -3.823). Comparison of the 3 solutions showed that ET was able to detect the highest OPG number (mean ranks: ET = 2.63; SU = 2.32; SA = 1.05; Chi-square: 26.52; P<0.001). The mean number of OPG of the samples positive at the same time to 2 and 3 methods was the following : VEDERE ALLEGATO.
The results show that the most effective coprological method for the diagnosis of Isospora oocysts in piglets is the Ridley-Allen concentration in ethyl acetate and formaldehyde method.
Research financed by MIUR and Sassari University (PRIN 2005
Mitomycin C in highly myopic eyes - Author reply
No full textOphthalmology. 2005 Feb;112(2):208-18; discussion 219.
Mitomycin C modulation of corneal wound healing after photorefractive keratectomy in highly myopic eyes.
Gambato C, Ghirlando A, Moretto E, Busato F, Midena E.
SourceRefractive Surgery Service and Antimetabolite Therapy Research Unit, Department of Ophthalmology, University of Padova, Padova, Italy.
Abstract
PURPOSE: To evaluate the role of topical mitomycin C in corneal wound healing (CWH) after photorefractive keratectomy (PRK) in highly myopic eyes.
DESIGN: Prospective, double-masked, randomized clinical trial.
PARTICIPANTS: Seventy-two eyes of 36 patients affected by high (>7 diopters) myopia.
METHODS: In each patient, one eye was randomly assigned to PRK with intraoperative topical 0.02% mitomycin C application, and the fellow eye was treated with a placebo. Postoperatively, mitomycin C-treated eyes received artificial tears (3 times daily, tapered in 3 months), whereas the fellow eye was treated with fluorometholone sodium 2% and artificial tears (3 times daily, tapered in 3 months).
MAIN OUTCOME MEASURES: Uncorrected visual acuity (UCVA) and best-corrected visual acuity (BCVA), contrast sensitivity, manifest refraction, and biomicroscopy. Contrast sensitivity was determined using the Pelli-Robson chart. Corneal confocal microscopy documented CWH.
RESULTS: Mean follow-up was 18 months (range, 12-36). No side effects or toxic effects were documented. At 12-month follow-up examination, UCVAs (logarithm of the minimum angle of resolution) were 0.4+/-0.48 and 0.5+/-0.53 (P = .03) in mitomycin C-treated eyes and corticosteroid-treated eyes, respectively. At 1 year, corneal haze developed in 20% of corticosteroid-treated eyes, versus 0% of mitomycin C-treated eyes. At 12, 24, and 36 months, corneal confocal microscopy showed activated keratocytes and extracellular matrix significantly more evident in untreated eyes (Ps = 0.004, 0.024, and 0.046, respectively).
CONCLUSION: Topical intraoperative application of 0.02% mitomycin C can reduce haze formation in highly myopic eyes undergoing PRK.
Comment in
Ophthalmology. 2006 Feb;113(2):357; author reply 357-8
Changing pattern of hepatitis A virus epidemiology in an area of high endemicity
No full textBackground: Continuous assessment of hepatitis A virus (HAV) seroepidemiology is a useful tool to control the risk of infection. Objectives:This study aimed to evaluate the changing patterns of anti-HAV seroprevalence in a population,which isgenerally considered to be anarea ofhigh endemicity. Patients and Methods: Overall, the results of 3349 sera collected during the period 2005-2008 from patients attending the University Hospital of Cagliari, Italy were studied; their mean age was 52.7 years, (s + 16.22). Patients with liver disease were excluded from the study. Age specific seroprevalence results were compared with those observed in similar previous studies carried out in the same area. Results: The overall prevalence of anti-HAV was 74.6% with consistently lower values in subjects younger than 40 years (17.5%; p < 0.0001) particularly in those under 30 years of age (8.9%, CI 5.8-11.9). A significant declining trend in age specific seroprevalence has been foundin people under 30 years;61% in 1988, 33% in 1995 and 8.9% in 2005-2008. Discussion: Our findings show that a significant decline inherd immunity has occurred in the last 20 years as a consequence of lower HAV circulation due to improvementsin socio-economical and hygienic conditions. Adolescents and young adults are becoming increasingly susceptible to HAV infections, as recent outbreaks of acute HAV hepatitis have occurred. Persistent environmental monitoring and the implementation of prevention measures must be considered in order to contain the risk related to this epidemiological shift
- …
