170,098 research outputs found
Cigarette smoking and silica exposure as determinants for the development of rheumatoid arthritis
No full textRheumatoid arthritis (RA) is an autoimmune, inflammatory disease with obscure etiology. This thesis is based on the hypothesis, that there is a link between respiratory exposures and the development of RA. Cigarette smoking and silica exposure were selected as the environmental exposures to study, as they have previously emerged as probable, but not fully elucidated, risk factors for RA.The major part of the analyses was based on a population based case-control study, comprising a population, aged 18-70 years, in Sweden. A case was defined as a person in the study base with newly developed RA, defined according to the American College of Rheumatology criteria. Controls were randomly selected from the study base, considering age, gender and residency. Smoking habits, silica exposure, HLA-DR shared epitope (SE) genes, Rheumatoid factor (RF) and antibodies to cyclic citrullinated peptides (anti-CCP) were analysed. Comparisons were made between smokers and never-smokers, between silica exposed men and unexposed men, between carriers of SE genes and persons without SE genes and between persons with various combinations of smoking habits and SE genes and never-smokers without SE genes.Comparisons included the risk of RA overall, and of RA of different RF status and anti-CCP status, by calculating odds ratio (OR) with 95 % confidence interval (95% CI). Smokers had an increased risk of RF+ and anti-CCP+, but not of RF-, or anti-CCP-, RA. Carriers of SE genes and silica exposed men had an increased risk of anti-CCP+, but not anti-CCP-, RA. The increased risk of RA associated with smoking, required a long duration, but merely a moderate intensity of smoking, increased with increasing cumulative dose of smoking and remained for several years after smoking cessation.Smoking was observed to be linked to occurrence of citrulline in lung cells. Evidence for an interaction between smoking and SE genes, and results compatible with, but not conclusive for, an interaction between smoking and silica exposure, in the development of RA, was seen. This thesis demonstrates that respiratory exposures may be associated with increased risk of developing RA and that this association may be linked to RA related antibodies and influenced by genotype.List of scientific papersI. Stolt P, Bengtsson C, Nordmark B, Lindblad S, Lundberg I, Klareskog L, Alfredsson L; EIRA study group (2003). Quantification of the influence of cigarette smoking on rheumatoid arthritis: results from a population based case-control study, using incident cases. Ann Rheum Dis. 62(9): 835-41. https://pubmed.ncbi.nlm.nih.gov/12922955II. Padyukov L, Silva C, Stolt P, Alfredsson L, Klareskog L, EIRA study group (2004). A gene-environment interaction between smoking and shared epitope genes in HLA-DR provides a high risk of seropositive rheumatoid arthritis. Arthritis Rheum. 50(10): 3085-92. https://pubmed.ncbi.nlm.nih.gov/15476204III. Stolt P, Kallberg H, Lundberg I, Sjogren B, Klareskog L, Alfredsson L (2004). Silica exposure is associated with increased risk of developing rheumatoid arthritis: results from the Swedish EIRA-study. Ann Rheum Dis. Aug 19. https://pubmed.ncbi.nlm.nih.gov/15319232IV. Klareskog L, Stolt P, Lundberg K, Kallberg H, Silva C, Grunewald J, Ronnelid J, Ulfgren AK, Harris H, Rantapaa-Dahlqvist S, Eklund A, Padyukov L, Alfredsson L, EIRA study group (2004). Gene-environment interactions in the etiology of RA; Smoking may trigger HLA-DR (SE) restricted immune reactions to autoantigens modified by citrullination. [Manuscript]V. Stolt P, Padyukov L, Kallberg H, Lundberg I, Klareskog L, Alfredsson L, EIRA study group (2004). Silica exposure is associated with increased risk of a restricted proportion of rheumatoid arthritis linked to antibodies to cyclic citrullinated peptides. [Manuscript]</p
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
Development and degeneration of dorsal root ganglia in the absence of the HMG-domain transcription factor Sox10
No full textThe HMG-domain transcription factor Sox10 is essential for the development of various neural crest derived lineages including glia and neurons of the peripheral nervous system (PNS). Within the PNS the most striking defect is the complete absence of glial differentiation whereas neurogenesis seemed initially normal. A degeneration of motoneurons and sensory neurons occurred later in development. The mechanism that leads to the dramatic effects on the neural crest derived cell lineages in the dorsal root ganglia (DRG), however, has not been examined up to now. Here, we provide a detailed analysis of proliferation and apoptosis in the DRG during the time of their generation and lineage segregation (between E 9.5 and E 11.5). We show that both increased apoptosis as well as decreased proliferation of neural crest cells contribute to the observed hypomorphism
Har företagen övergett budgeten? - en studie om budgetens användning i de börsnoterade företagen
No full textBakgrund och problem: Budgetering är något som är väl etablerat då det har funnits i snart 40 år i Sverige. Budget har flera syften i ett företag bland annat används den för planering, styrning av verksamheten, kontroll och utvärdering. Under den här tiden har dock omvärlden förändrats en hel del. Det har skett en avreglering och globalisering med en mer föränderlig omvärld som följd. Detta ställer nya krav på ett företag som många menar att budgeten inte kan leva upp till. Det har förekommit mycket artiklar i tidskrifter om att budgeten borde avskaffas. Hur är det då ute i företagen finns budgeten kvar eller håller den på att överges eller kompletteras?
Syfte: Att kartlägga och beskriva hur den fasta årliga budgeten används i de börsnotera-de företagen i Sverige. En jämförelse ska också göras med en liknande studie som gjor-des 1997 för att se om det finns några skillnader. Dessutom ska studien försöka belysa vilka skillnader det är mellan de företag som använder sig av fast årlig budget eventuellt med något eller några komplement kontra de som övergett eller funderar på att överge den.
Avgränsningar: Undersökningen begränsar sig till att undersöka budgetens användning på koncernnivå bland de svenska börsbolag som finns med på listorna Mest omsatta, A-listan, Attract 40 och O-listan.
Metod: Det handlar om en kvantitativ metod eftersom en kartläggning ska ske av bud-getens användning i de svenska börsbolagen. En enkätundersökning sändes ut till alla företag på de berörda börslistorna, se avgränsningar ovan. Det handlar om 277 företag. Enkäten besvarades via Internet. Det empiriska materialet analyserades sedan utifrån den teoretiska referensramen.
Resultat och slutsatser: I studien framkom att 84 % av företagen använder sig av fast årlig budget mot 89 % 1997. Det framkom också att de allra flesta anser att den fasta år-liga budgeten bygger på osäkra framtidsutsikter. Det är ett av de större problemen anser framförallt de som övergett budgeten till förmån för rullande budgetar/prognoser ofta kompletterat med Balanced Scorecard och/eller benchmarking. Bland de som inte över-gett den fasta årliga budgeten är det många som kompletterat den med reviderad bud-get/prognos men även bland dessa används rullande budgetar/prognoser och Balanced Scorecard och/eller benchmarking.
Förslag till fortsatt forskning: En studie om hur budgetens användning är i de mindre och medelstora företagen kan vara intressant att göra för att se eventuella skillnader. Den här undersökningen går ut på att se användningen av budgeten på koncernnivå. Det kan vara intressant att se om det skiljer sig mellan hur budgeten används på högsta ni-vån kontra längre ned i organisationern
Characterisation of a Coriolis flow meter for fuel consumption measurements in realistic drive cycle tests
No full textWhen testing light-duty and heavy-duty vehicles on chassis dynamometers, as in the WLTP, or engines on engine test benches, as in the WHDC, it is required to measure the fuel consumption. In the preferable case, the measurement of the fuel consumption is carried out with suitable flow meters. These require high measurement accuracy in a wide flow range, independent of the fuel type, as the flow rate range is often very large and depends on the power range of the vehicle engines. Moreover, the fuel flow rate in the test cycles is very dynamically related to the loads. In the scope of the ongoing EMPIR Joint Research Project 20IND13 SAFEST the dynamic flow behaviour as well as the measurement accuracy of flow meters for different types of fuels are investigated. This paper presents first results from the realisation of dynamic flow profiles, and flow measurements with a Coriolis Flow Meter with different representative fuels in a wide density and viscosity range and a wide flow rate range at different fuel temperatures
A Multi-Language Comparison of Influences on Author Verification using Character N-Grams
No full textWe create a new multi-language corpus for author verification based on Wikipedia talkpages, and evaluate the influence that differences in topic and time have on character n-gram author profiles. Topic alignment between two texts is found to increase author verification precision, and an authors writing style is found to change over time, but not more significantly after 3 years than after 1 year.Information ArchitectureWISElectrical Engineering, Mathematics and Computer Scienc
A 0.12mm<sup>2</sup> Wien-Bridge Temperature Sensor with 0.1°C (3σ) Inaccuracy from -40°C to 180°C
No full text Resistor-based temperature sensors can achieve much higher resolution and energy efficiency than conventional BJT-based sensors [1], but they typically occupy more area (> 0.25 mm 2 ) and have lower operating temperatures (le 125 {circ} {C}) [2]-[4]. This work describes a 0.12mm 2 resistor-based sensor that uses a Wien-bridge (WB) filter to achieve 0.1 {circ} {C} (3 sigma) inaccuracy from - 40 {circ} {C} to 180 {circ} {C}. Compared to a state-of-the-art WB sensor [4], it occupies 6 × less area and achieves comparable relative accuracy over a 76% wider operating range. Session 10.3 Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Electronic InstrumentationMicroelectronic
A ±25A Versatile Shunt-Based Current Sensor with 10kHz Bandwidth and ±0.25% Gain Error from -40°C to 85°C Using 2-Current Calibration
No full textAccurate current sensing is critical in many industrial applications, such as battery management and motor control. Precise shunt-based current sensors have been reported with gain errors of less than 1% over the industrial temperature range (-40°C to 85°C) [1]–[4]. However, since they are intended for coulomb counting, their bandwidth is limited to a few tens of Hz, making them unsuitable for battery impedance or motor-current sensing. This paper presents a current sensor with a wide (10kHz) bandwidth and a tunable temperature compensation scheme (TCS), which allows it to be flexibly used with different types of shunts while maintaining high accuracy. A low-cost room-temperature calibration scheme is proposed to optimize gain flatness over temperature by exploiting the shunt's self-heating at large currents. Over the industrial temperature range and a ±25A current range, it achieves state-of-the-art gain error (±0.25%) with both low-cost PCB and stable metal-alloy shunts.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Electronic InstrumentationMicroelectronic
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