131 research outputs found
The 85$Rb(p,n)85Sr reaction and the modified proton optical potential
The cross sections of the astrophysically relevant 85$Rb(p,n)85Srg,m reaction
have been measured between Ec.m. = 2.16 and 3.96 MeV. The cross sections have
been derived by measuring the gamma radiation following the beta decay of the
reaction products. A comparison with the predictions of Hauser-Feshbach
calculations using the NON-SMOKER code confirms a recently derived modification
of the global optical proton potential.Comment: CGS XIII conferenc
Loci Memoriae Hungaricae
PĂĄl S. Varga: Introduction - 7 ; 1. Theoretical Approaches - 21 ; Aleida Assmann: The Transformative Power of Memory - 22 ; Jan Assmann: Communicative and Cultural - 36 ; Pim den Boer: Lieux de MĂ©moire in Comparative Perspective - 44 ; 2.Discussion/Diskussion - 51 ;
PĂĄl S. Varga: Kollektives GedĂ€chtnis und Geschichtswissenschaften (Diskussionseröffnung) - 52 ; Harald D. Gröller: Diskussionsbeitrag bez. des Eröffnungsreferats von PĂĄl S. Varga - 59 ; Csaba Gy. Kiss: Diskussionsbeitrag zum Eröffnungsreferat von PĂĄl S. Varga - 64 ; Ferenc Velkey: GedĂ€chtnis und Geschichte. Kommentare zur Diskussionseröffnung von PĂĄl S. Varga - 67 ; PĂ©ter György: Memory Fallen Apart: the Case of Two Cemeteries - 72 ; Aleida Assmann: Response to PĂ©ter György, âMemory Fallen Apart: the Case of Two Cemeteriesâ - 78 ; TamĂĄs BĂ©nyei: Remembering from Outside: A Response to PĂ©ter Györgyâs Essay - 81 ; 3. Ungarische Erinnerungsorte im zentraleuropĂ€ischen Kontext - 89 ; IstvĂĄn Bitskey: Ein religiöser Erinnerungsort in Mitteleuropa: Tyrnau (Nagyszombat, Trnava), das âKlein-Româ (Eine Fallstudie) - 90 ; MĂĄrta Fata: Erinnerungsort Bauernkrieg? MĂŒntzer und DĂłzsa in der Geschichtspolitik der DDR und der Volksrepublik Ungarn im Vergleich - 101 ; 4. The Socio-Psychological Approach - 115 ; Ăkos MĂŒnnich, IstvĂĄn Hidegkuti: Structural Characteristics of Sites of National Memory - 11
Polymorphisms in gene encoding TRPV1-receptor involved in pain perception are unrelated to chronic pancreatitis
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79505.pdf (publisher's version ) (Open Access
Sexual Behaviour and HPV Infections in 18 to 29 Year Old Women in the Pre-Vaccine Era in the Netherlands
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71058.pdf ( ) (Open Access)BACKGROUND: Infection with Human Papillomavirus (HPV) is a necessary event in the multi-step process of cervical carcinogenesis. Little is known about the natural history of HPV infection among unscreened young adults. As prophylactic vaccines are being developed to prevent specifically HPV 16 and 18 infections, shifts in prevalence in the post vaccine era may be expected. This study provides a unique opportunity to gather baseline data before changes by nationwide vaccination occur. METHODS AND PRINCIPAL FINDINGS: This cross-sectional study is part of a large prospective epidemiologic study performed among 2065 unscreened women aged 18 to 29 years. Women returned a self-collected cervico-vaginal specimen and filled out a questionnaire. All HPV DNA-positive samples (by SPF(10) DEIA) were genotyped using the INNO-LiPA HPV genotyping assay. HPV point prevalence in this sample was 19%. Low and high risk HPV prevalence was 9.1% and 11.8%, respectively. A single HPV-type was detected in 14.9% of all women, while multiple types were found in 4.1%. HPV-types 16 (2.8%) and 18 (1.4%) were found concomitantly in only 3 women (0.1%). There was an increase in HPV prevalence till 22 years. Multivariate analysis showed that number of lifetime sexual partners was the most powerful predictor of HPV positivity, followed by type of relationship, frequency of sexual contact, age, and number of sexual partners over the past 6 months. CONCLUSIONS AND SIGNIFICANCE: This study shows that factors independently associated with HPV prevalence are mainly related to sexual behaviour. Combination of these results with the relative low prevalence of HPV 16 and/or 18 may be promising for expanding the future target group for catch up vaccination. Furthermore, these results provide a basis for research on possible future shifts in HPV genotype prevalence, and enable a better estimate of the effect of HPV 16-18 vaccination on cervical cancer incidence
hMMS2 serves a redundant role in human PCNA polyubiquitination
<p>Abstract</p> <p>Background</p> <p>In yeast, DNA damage leads to the mono and polyubiquitination of the sliding clamp PCNA. Monoubiquitination of PCNA is controlled by RAD18 (E3 ligase) and RAD6 (E2 conjugating enzyme), while the extension of the monoubiquitinated PCNA into a polyubiquitinated substrate is governed by RAD5, and the heterodimer of UBC13/MMS2. Each modification directs a different branch of the DNA damage tolerance pathway (DDT). While PCNA monoubiquitination leads to error-prone bypass via TLS, biochemical studies have identified MMS2 along with its heteromeric partner UBC13 to govern the error-free repair of DNA lesions by catalyzing the formation of lysine 63-linked polyubiquitin chains (K63-polyUb). Recently, it was shown that PCNA polyubiquitination is conserved in human cells and that this modification is dependent on RAD18, UBC13 and SHPRH. However, the role of hMMS2 in this process was not specifically addressed.</p> <p>Results</p> <p>In this report we show that mammalian cells in which MMS2 was reduced by siRNA-mediated knockdown maintains PCNA polyubiquitination while a knockdown of RAD18 or UBC13 abrogates PCNA ubiquitination. Moreover, the additional knockdown of a UEV1A (MMS2 homolog) does not deplete PCNA polyubiquitination. Finally, mouse embryonic stem cells null for MMS2 with or without the additional depletion of mUEV1A continue to polyubiquitinated PCNA with normal kinetics.</p> <p>Conclusion</p> <p>Our results point to a high level of redundancy in the DDT pathway and suggest the existence of another hMMS2 variant (hMMSv) or complex that can compensate for its loss.</p
Assessing circadian rhythms in propofol PK and PD during prolonged infusion in ICU patients
This study evaluates possible circadian rhythms during prolonged propofol infusion in patients in the intensive care unit. Eleven patients were sedated with a constant propofol infusion. The blood samples for the propofol assay were collected every hour during the second day, the third day, and after the termination of the propofol infusion. Values of electroencephalographic bispectral index (BIS), arterial blood pressure, heart rate, blood oxygen saturation and body temperature were recorded every hour at the blood collection time points. A two-compartment model was used to describe propofol pharmacokinetics. Typical values of the central and peripheral volume of distribution and inter-compartmental clearance were VC = 27.7 l, VT = 801 l, and CLD = 2.73 l/min. The systolic blood pressure (SBP) was found to influence the propofol metabolic clearance according to Cl (l/min) = 2.65·(1 â 0.00714·(SBP â 135)). There was no significant circadian rhythm detected with respect to propofol pharmacokinetics. The BIS score was assessed as a direct effect model with EC50 equal 1.98 mg/l. There was no significant circadian rhythm detected within the BIS scores. We concluded that the lightâdark cycle did not influence propofol pharmacokinetics and pharmacodynamics in intensive care units patients. The lack of nightâday differences was also noted for systolic blood pressure, diastolic blood pressure and blood oxygenation. Circadian rhythms were detected for heart rate and body temperature, however they were severely disturbed from the pattern of healthy patients
Rapid measurement of intravoxel incoherent motion (IVIM) derived perfusion fraction for clinical magnetic resonance imaging
Objective This study aimed to investigate the reliability of intravoxel incoherent motion (IVIM) model derived parameters D and f and their dependence on b value distributions with a rapid three b value acquisition protocol. Materials and methods Diffusion models for brain, kidney, and liver were assessed for bias, error, and reproducibility for the estimated IVIM parameters using b values 0 and 1000, and a b value between 200 and 900, at signal-to-noise ratios (SNR) 40, 55, and 80. Relative errors were used to estimate optimal b value distributions for each tissue scenario. Sixteen volunteers underwent brain DW-MRI, for which bias and coefficient of variation were determined in the grey matter. Results Bias had a large influence in the estimation of D and f for the low-perfused brain model, particularly at lower b values, with the same trends being confirmed by in vivo imaging. Significant differences were demonstrated in vivo for estimation of D (P = 0.029) and f (P < 0.001) with [300,1000] and [500,1000] distributions. The effect of bias was considerably lower for the high-perfused models. The optimal b value distributions were estimated to be brain500,1000, kidney300,1000, and liver200,1000. Conclusion IVIM parameters can be estimated using a rapid DW-MRI protocol, where the optimal b value distribution depends on tissue characteristics and compromise between bias and variability
Calcium Influx Rescues Adenylate Cyclase-Hemolysin from Rapid Cell Membrane Removal and Enables Phagocyte Permeabilization by Toxin Pores
Bordetella adenylate cyclase toxin-hemolysin (CyaA) penetrates the cytoplasmic membrane of phagocytes and employs two distinct conformers to exert its multiple activities. One conformer forms cation-selective pores that permeabilize phagocyte membrane for efflux of cytosolic potassium. The other conformer conducts extracellular calcium ions across cytoplasmic membrane of cells, relocates into lipid rafts, translocates the adenylate cyclase enzyme (AC) domain into cells and converts cytosolic ATP to cAMP. We show that the calcium-conducting activity of CyaA controls the path and kinetics of endocytic removal of toxin pores from phagocyte membrane. The enzymatically inactive but calcium-conducting CyaA-ACâ toxoid was endocytosed via a clathrin-dependent pathway. In contrast, a doubly mutated (E570K+E581P) toxoid, unable to conduct Ca2+ into cells, was rapidly internalized by membrane macropinocytosis, unless rescued by Ca2+ influx promoted in trans by ionomycin or intact toxoid. Moreover, a fully pore-forming CyaA-ÎAC hemolysin failed to permeabilize phagocytes, unless endocytic removal of its pores from cell membrane was decelerated through Ca2+ influx promoted by molecules locked in a Ca2+-conducting conformation by the 3D1 antibody. Inhibition of endocytosis also enabled the native B. pertussis-produced CyaA to induce lysis of J774A.1 macrophages at concentrations starting from 100 ng/ml. Hence, by mediating calcium influx into cells, the translocating conformer of CyaA controls the removal of bystander toxin pores from phagocyte membrane. This triggers a positive feedback loop of exacerbated cell permeabilization, where the efflux of cellular potassium yields further decreased toxin pore removal from cell membrane and this further enhances cell permeabilization and potassium efflux
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