170,053 research outputs found
Improvement in estimating the population mean in simple random sampling
No full textAbstractThis paper proposes some estimators for the population mean using the ratio estimators presented in [C. Kadilar, H. Cingi, Ratio estimators in simple random sampling, Applied Mathematics and Computation 151 (2004) 893–902] and shows that all proposed estimators are always more efficient than the ratio estimators. This result is also supported by a numerical example
INTERACTION OF HEPARAN-SULFATE AND ITS FRACTIONS WITH ENDOTHELIAL-CELLS IN CULTURE
No full textIn the present work we have investigated the binding capacity, to cell membrane of bovine aortic endothelial cells (BAEC) cultured in vitro, of heparan sulfate (Mr 11.1 kDa) and its four fractions named A (Mr 24.5 kDa), B (Mr 10.7 kDad), C (Mr 9.1 kDa) and D (Mr 6.8 kDa). Experiments were performed in comparison with unfractionated heparin (Mr 12.9 kDa). The binding of the examined compounds was determined by the degree of displacement of [H-3]-heparin from the cell membrane. The efficiency of heparan sulfate fractions B, C and D in displacing labelled heparin was found to decrease in function with the decrease of the molecular masses of the compounds, [H-3]-heparin could be efficiently displaced mainly by heparin and fraction A, the fraction which has the highest molecular weight and represents only 3.8% of the unfractionated HA 90681. These experimental results may confirm that molecular mass is an important feature for the interaction of glycosaminoglycans with the specific binding sites on the cell surface
Dimeric complexes of palladium with hydrazone. Crystal structure of bis(acetone methyl- phenylhydrazone) tetrachlorodipalladium(II) chloroform solvate (1:1)
No full textThe structure of the title complex was detd. by Patterson and Fourier syntheses and refined by full-matrix least-squares to R = 0.059 for 1144 reflections. The compd. is monoclinic, space group P21/c, with a 19.166, b 11.235, c 14.191 Å, and β 103.1°; Z = 4. PdCl2L2 (L = R2C:NNMePh, R = Me, Et) and Pd2Cl4L2 (R = Et) were also prepd. and characterized by IR and NMR spectra
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
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
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
A survey on chronic rhinosinusitis: opinions from experts of 50 countries
No full textChronic rhinosinusitis (CRS) is a very prevalent inflammatory disease. Treatments vary in different countries. In the present study, we explored the approaches of physicians in 50 countries. In this cross-sectional study, a rhinosinusitis survey (RSS) was completed by Honorary and Corresponding Members (otorhinolaryngologists) of the Italian Society of Rhinology. In 79.1 % of the 50 countries, the proportion of patients suffering from CRS was 15 %. Nasal symptoms were more intense in winter (46 % of countries), and spring and autumn (22 %). The most common symptoms were nasal obstruction (86 %), postnasal drip (82 %) and headache (52 %). The most common investigative modalities in the assessment of CRS are paranasal sinus CT, fiberoptic endoscopy, and anterior rhinoscopy. CRS patients were principally treated by otorhinolaryngologists (70 %). Medical treatments included nasal corticosteroids (90 %), nasal washes (68 %), and nasal decongestants (32 %). In 88 % of countries, more than 50 %, or "about 50 %", of all patients reported subjective symptom improvement after treatment. In most of the countries, surgery was required by 20-35 % of all CRS patients. During post-surgery follow-up, nasal washes (90 %), nasal corticosteroids (76 %), and systemic antibiotics (32 %) were prescribed. In 20-40 % of all patients, CRS was associated with nasal polyps. In such patients, the medical treatment options were nasal corticosteroids (90 %), systemic corticosteroids (50 %), nasal washes (46 %), and systemic antibiotics (34 %). Treatment of CRS patients varies in different countries. Paranasal sinus CT is the most common investigative modality in the assessment of CRS, and nasal corticosteroids are the first-line treatment, in the absence or presence of nasal polyps
Influence of allergic rhinitis in children and adolescents with recurrent headache
No full textIntroduction: Migraine and allergies are common occurrences. The aim of this study was to investigate the relationship between respiratory allergy and cephalalgic migraine in childhood.Materials and Methods: We screened 800 children for headache and its characteristics. After that we investigated the presence of allergy performing prick tests, rhinoscopy, endoscopy, rhinomanometry, nasal cytology and mucociliary clearance tests.Results: Out of 800 children screened, 96 suffered from headache. Among these, 67 resulted to suffered from both headache and allergy. We found a significant correlation between allergy and headache onset in the morning and headache onset in the evening in non-allergic subjects. The average duration of the a headache attack was independent from the presence of allergy, as well as the frequency of the cephalalgy attacks, and the localization of the pain. Prodromal symptoms connected with headache were reported to be: dizziness, aurea, sparkling scotoma, nausea and vomiting, and they were associated with absence of allergy. We also found a relationship between female gender and headache onset, but in teen-agers only. Paracetamol or FANS were used in the majority of cases, but antihistaminic therapy and/or nasal topical sprays were also reported.Discussion: For an effective diagnostic and therapeutic approach to migraine, the pediatrician should take into account atopy and its related allergic manifestations requiring a consultation with an otolaryngologist or allergist, if necessary. Our findings also stress the potential role of medicines that are not usually utilized for migraine attacks, such as antihistamines or decongestionant nasal sprays
The International Study of the Allergic Rhinitis Survey: outcomes from 4 geographical regions.
No full textBackground
Allergic rhinitis (AR) is a global health problem and is characterised by one or more symptoms, including sneezing, itching, nasal congestion and rhinorrhea.
Objective
We investigated the features of AR and the physician's approach to the management of AR patients in four geographical regions.
Methods
In this cross-sectional study, a questionnaire survey concerning AR was completed by Honorary and Corresponding Members of the Italian Society of Rhinology from different countries among 4 world geographical regions—Asia, Europe, the Americas, and Africa.
Results
The prevalence of AR was reported to be 15%–25%. Children and adolescents, as well as young adults, were the age groups more affected by AR with comorbidities of asthma, sinusitis, conjunctivitis, and nasal polyposis. Nasal symptoms of AR were more intense in the spring (51.92%) and autumn (28.85%). The most common aero-allergens were pollen and mites (67.31%), animal dander and pollutants (23.08%), and fungal allergens (21.15%). Allergen-specific immunotherapy was prescribed for both perennial and seasonal allergens (32.69%) via sublingual swallow (46.15%) and subcutaneous (32.69%) routes. For the AR patients, the most prescribed drugs were intranasal corticosteroids (86.54%) and oral H1-antihistamines (82.69%).
Conclusion
A network of experts can improve our knowledge concerning AR epidemiology, and together with guidelines, could assist practitioners and otolaryngologists in standardising the diagnosis and treatment of AR
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