169,748 research outputs found
Glycemic load in relation to hepatocellular carcinoma among patients with chronic hepatitits infection
No full textBackground: Chronic infections with hepatitis B virus (HBV) and hepatitis C virus (HCV) are of paramount etiologic importance for hepatocellular carcinoma (HCC), but other factors are likely to be important. The association of diabetes mellitus and obesity with HCC raises the possibility that dietary glycemic load (GL) may interact with chronic hepatitis infection in the causation of HCC. Patients and methods: We conducted a case-control study of 333 HCC patients and 360 controls in Athens, Greece. Third-generation assays were used to determine chronic HBV and HCV infection and information from a semiquantitative food frequency questionnaire to estimate dietary GL. Results: After adjustment for possible confounding factors through multiple logistic regression, we found a nonsignificant positive association between GL and HCC, which was exclusively accounted for by a positive association between GL and HCC cases with chronic infection with hepatitis B and/or C. For the latter group of patients, the odds ratio at the highest compared with the lowest GL quintile was 1.95 (95% confidence interval 1.09-3.48). The association was strengthened after exclusion of subjects with diabetes. Conclusion: Our results indicate that, among patients with chronic infection with HBV and/or HCV, reduction of dietary GL could reduce risk or delay development of HCC
Learning Dialogue Strategies from Older and Younger Simulated Users
No full textOlder adults are a challenging user group because their behaviour can be highly variable. To the best of our knowledge, this is the first study where dialogue strategies are learned and evaluated with both simulated younger users and simulated older users. The simulated users were derived from a corpus of interactions with a strict system-initiative spoken dialogue system (SDS). Learning from simulated younger users leads to a policy which is close to one of the dialogue strategies of the underlying SDS, while the simulated older users allow us to learn more flexible dialogue strategies that accommodate mixed initiative. We conclude that simulated users are a useful technique for modelling the behaviour of new user groups
Η συμμετοχή της πρωτεοσωμικής αποικοδόμησης στη γήρανση και τον νευροεκφυλισμό. Μελέτη της προστατευτικής δράσης της απόκρισης σε θερμικό σοκ στο νεκροτικό κυτταρικό θάνατο
No full textΗ διατήρηση της ομοιόστασης των πρωτεϊνών είναι ζωτικής σημασίας για τη φυσιολογική λειτουργία του κυττάρου. Το πρωτεόσωμα αποτελεί την κύρια μηχανή αποικοδόμησης μακρόβιων 4
Georgila K. Master thesis
πρωτεϊνών. Τα βασικά υποστρώματα του πρωτεοσώματος είναι οξειδωμένες, μετουσιωμένες, πρόωρα τερματισμένες και γενικότερα βλαβερές για το κύτταρο πρωτεΐνες. Στη παρούσα μελέτη, χρησιμοποιήσαμε ως μοντέλο οργανισμό, το νηματώδη Caenorhabditis elegans προκειμένου να διερευνήσουμε εάν η ενίσχυση της πρωτεοσωμικής λειτουργίας, μέσω υπερέκφρασης της κεντρική περιοριστικής υπομονάδας του πρωτεοσώματος, PBS-5 οδηγεί σε αυξημένο προσδόκιμο ζωής. Τα μοριακά μονοπάτια που αφορούν στην γήρανση είναι συντηρημένα και πολύ καλά χαρακτηρισμένα στον νηματώδη. Στοχεύουμε να εξετάσουμε με γενετική ανάλυση εάν η αυξημένη πρωτεϊνική ανακύκλωση επεκτείνει το προσδόκιμο ζωής μέσω ή ανεξάρτητα από τα ήδη γνωστά μοριακά μονοπάτια που διέπουν τη γήρανση. Ακόμη, διερευνήσαμε την επίπτωση της υπερέκφρασης της περιοριστικής υπομονάδας pbs-5 στην αντίσταση των σκουληκιών στο οξειδωτικό στρες. Επιπλέον, μελετήσαμε την επίδραση της αυξημένης πρωτεοσωμικής λειτουργίας σε μοντέλα νευροεκφυλιστικών ασθενειών στον νηματώδη. Η κατανόηση των μηχανισμών ενίσχυσης του πρωτεοσώματος που συμβάλουν στην αύξηση του προσδόκιμου ζωής, στην αντίσταση στο οξειδωτικό στρες και στη καταστολή του νευροεκφυλισμού μπορεί να οδηγήσει στη ανάπτυξη νέων αντιγηραντικών και θεραπευτικών παρεμβάσεων.Preservation of cellular protein homeostasis (proteostasis) is of critical importance. The cell employs various mechanisms to achieve this. The main machinery for the degradation of long-lived 5
Georgila K. Master thesis
or damaged proteins is the proteasome. We exploited the simple model organism Caenorhabditis elegans to examine whether enhancement of the proteasome activity, via overexpression of the core, rate-limiting proteasomal subunit, pbs-5 can act beneficially on the lifespan of the nematode. C. elegans’ lifespan is regulated by several conserved and well characterized pathways. We aim to investigate, by genetic analysis, whether increased protein turnover confers lifespan extension by acting through those pathways. In addition, we examined whether pbs-5 overexpression and consequently increased proteasomal degradation confers oxidative stress resistance. Finally, there is a striking connection between aging and the onset of many neurodegenerative disorders. We took advantage of an established model of neurodegeneration in C. elegans. We examined whether enhancement of the main cellular degradation machinery may lead to suppression of neurodegeneration. Understanding the mechanism by which preservation of cellular proteostasis, via enhancement of the proteasomal activity, extends lifespan, confers oxidative stress resistance and suppresses neurodegeneration may lead to new anti-aging strategies and therapeutic interventions.
1. INTRODUCTIO
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 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
An Article About Albertus C. Van Raalte, Author Unknown, Except for Parts Taken from an Article by Anna C. Post
No full textAn article about Albertus C. Van Raalte, author unknown, except for parts taken from an article by Anna C. Post. The author knew first generation persons in the Holland settlement and therefore, the article has some value.https://digitalcommons.hope.edu/vrp_1890s/1012/thumbnail.jp
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