SwePub
Sök i SwePub databas

  Utökad sökning

Träfflista för sökning "WFRF:(Snijders M. A. J.) "

Sökning: WFRF:(Snijders M. A. J.)

  • Resultat 1-10 av 10
Sortera/gruppera träfflistan
   
NumreringReferensOmslagsbildHitta
1.
  • Edelson, R. A., et al. (författare)
  • Multiwavelength observations of short-timescale variability in NGC 4151. IV. Analysis of multiwavelength continuum variability
  • 1996
  • Ingår i: Astrophysical Journal. - 0004-637X .- 1538-4357. ; 470:1, s. 364-377377
  • Tidskriftsartikel (refereegranskat)abstract
    • <p>For pt.III see ibid., vol.470, no.1, p.349-63 (1996). Combines data from the three preceding papers in order to analyze the multi wave-band variability and spectral energy distribution of the Seyfert 1 galaxy NGC 4151 during the 1993 December monitoring campaign. The source, which was near its peak historical brightness, showed strong, correlated variability at X-ray, ultraviolet, and optical wavelengths. The strongest variations were seen in medium-energy (~1.5 keV) X-rays, with a normalized variability amplitude (NVA) of 24%. Weaker (NVA=6%) variations (uncorrelated with those at lower energies) were seen at soft gamma-ray energies of ~100 keV. No significant variability was seen in softer (0.1-1 keV) X-ray bands. In the ultraviolet/optical regime, the NVA decreased from 9% to 1% as the wavelength increased from 1275 to 6900 Aring. These data do not probe extreme ultraviolet (1200 Aring to 0.1 keV) or hard X-ray (250 keV) variability. The phase differences between variations in different bands were consistent with zero lag, with upper limits of lsim0.15 day between 1275 Aring and the other ultraviolet bands, lsim0.3 day between 1275 Aring and 1.5 keV, and lsim1 day between 1275 and 5125 Aring. These tight limits represent more than an order of magnitude improvement over those determined in previous multi-wave-band AGN monitoring campaigns. The ultraviolet fluctuation power spectra showed no evidence for periodicity, but were instead well fitted with a very steep, red power law (ales-2.5)</p>
  •  
2.
  • Crenshaw, D. M., et al. (författare)
  • Multiwavelength observations of short-timescale variability in NGC 4151. I. Ultraviolet observations
  • 1996
  • Ingår i: Astrophysical Journal. - 0004-637X .- 1538-4357. ; 470:1, s. 322-335335
  • Tidskriftsartikel (refereegranskat)abstract
    • <p>Presents the results of an intensive ultraviolet monitoring campaign on the Seyfert 1 galaxy NGC 4151, as part of an effort to study its short-timescale variability over a broad range in wavelength. The nucleus of NGC 4151 was observed continuously with the International Ultraviolet Explorer for 9.3 days, yielding a pair of LWP and SWP spectra every ~70 minutes, and during 4 hr periods for 4 days prior to and 5 days after the continuous-monitoring period. The sampling frequency of the observations is an order of magnitude higher than that of any previous UV monitoring campaign on a Seyfert galaxy. The continuum fluxes in bands from 1275 to 2688 Aring went through four significant and well-defined ldquoeventsrdquo of duration 2-3 days during the continuous-monitoring period. The authors find that the amplitudes of the continuum variations decrease with increasing wavelength, which extends a general trend for this and other Seyfert galaxies to smaller timescales (i.e., a few days). The continuum variations in all the UV bands are simultaneous to within an accuracy of ~0.15 days, providing a strict constraint on continuum models. The emission-line light curves show only one major event during the continuous monitoring (a slow rise followed by a shallow dip) and do not correlate well with continuum light curves over the short duration of the campaign, because the timescale for continuum variations is apparently smaller than the response times of the emission lines</p>
  •  
3.
  • Meijer, Chris J. L. M., et al. (författare)
  • Guidelines for human papillomavirus DNA test requirements for primary cervical cancer screening in women 30 years and older
  • 2009
  • Ingår i: International Journal of Cancer. - John Wiley and Sons Inc.. - 0020-7136. ; 124:3, s. 516-520
  • Tidskriftsartikel (refereegranskat)abstract
    • Given the strong etiologic link between high-risk HPV infection and cervical cancer high-risk HPV testing is now being considered as an alternative for cytology-based cervical cancer screening. Many test systems have been developed that can detect the broad spectrum of hrHPV types in one assay. However, for screening purposes the detection of high-risk HPV is not inherently useful unless it is informative for the presence of high-grade cervical intraepithelial neoplasia (CIN 2/3) or cancer. Candidate high-risk HPV tests to be used for screening should reach an optimal balance between clinical sensitivity and specificity for detection of high-grade CIN and cervical cancer to minimize redundant or excessive follow-up procedures for high-risk HPV positive women without cervical lesions. Data from various large screening studies have shown that high-risk HPV testing by hybrid capture 2 and GP5+/6+-PCR yields considerably better results in the detection of CIN 2/3 than cytology. The data from these studies can be used to guide the translation of high-risk HPV testing into clinical practice by setting standards of test performance and characteristics. On the basis of these data we have developed guidelines for high-risk HPV test requirements for primary cervical screening and validation guidelines for candidate HPV assays. (C) 2008 Wiley-Liss, Inc.
  •  
4.
  • Bleeker, M. C. G., et al. (författare)
  • Penile cancer: epidemiology, pathogenesis and prevention
  • 2009
  • Ingår i: World Journal of Urology. - Springer. - 1433-8726. ; 27:2, s. 141-150
  • Tidskriftsartikel (refereegranskat)abstract
    • Penile cancer is a disease with a high morbidity and mortality. Its prevalence is relatively rare, but the highest in some developing countries. Insight into its precursor lesions, pathogenesis and risk factors offers options to prevent this potentially mutilating disease. This review presents an overview of the different histologically and clinically identified precursor lesions of penile cancer and discusses the molecular pathogenesis, including the role of HPV in penile cancer development. A systematic review of the literature evaluating penile carcinogenesis, risk factors and molecular mechanisms involved. Careful monitoring of men with lichen sclerosis, genital Bowen's disease, erythroplasia of Queyrat and bowenoid papulosis seems useful, thereby offering early recognition of penile cancer and, subsequently, conservative therapeutic options. Special attention is given to flat penile lesions, which contain high numbers of HPV. Their role in HPV transmission to sexual partners is highlighted, but their potential to transform as a precursor lesion into penile cancer has been unsatisfactorily explored. Further research should not only focus on HPV mediated pathogenic pathways but also on the non-HPV related molecular and genetic factors that play a role in penile cancer development. Options for prevention of penile cancer include (neonatal) circumcision, limitation of penile HPV infections (either by prophylactic vaccination or condom use), prevention of phimosis, treatment of chronic inflammatory conditions, limiting PUVA treatment, smoking cessation and hygienic measures.
  •  
5.
  • Barbato, A, et al. (författare)
  • Primary ciliary dyskinesia: a consensus statement on diagnostic and treatment approaches in children.
  • 2009
  • Ingår i: The European respiratory journal : official journal of the European Society for Clinical Respiratory Physiology. - 0903-1936. ; 34:6, s. 1264-76
  • Tidskriftsartikel (refereegranskat)abstract
    • Primary ciliary dyskinesia (PCD) is associated with abnormal ciliary structure and function, which results in retention of mucus and bacteria in the respiratory tract, leading to chronic oto-sino-pulmonary disease, situs abnormalities and abnormal sperm motility. The diagnosis of PCD requires the presence of the characteristic clinical phenotype and either specific ultrastructural ciliary defects identified by transmission electron microscopy or evidence of abnormal ciliary function. Although the management of children affected with PCD remains uncertain and evidence is limited, it remains important to follow-up these patients with an adequate and shared care system in order to prevent future lung damage. This European Respiratory Society consensus statement on the management of children with PCD formulates recommendations regarding diagnostic and therapeutic approaches in order to permit a more accurate approach in these patients. Large well-designed randomised controlled trials, with clear description of patients, are required in order to improve these recommendations on diagnostic and treatment approaches in this disease.
  •  
6.
  • Kuehni, C E, et al. (författare)
  • Factors influencing age at diagnosis of primary ciliary dyskinesia in European children.
  • 2010
  • Ingår i: The European respiratory journal : official journal of the European Society for Clinical Respiratory Physiology. - 1399-3003. ; 36:6, s. 1248-58
  • Tidskriftsartikel (refereegranskat)abstract
    • Primary ciliary dyskinesia (PCD) is a hereditary disorder of mucociliary clearance causing chronic upper and lower airways disease. We determined the number of patients with diagnosed PCD across Europe, described age at diagnosis and determined risk factors for late diagnosis. Centres treating children with PCD in Europe answered questionnaires and provided anonymous patient lists. In total, 223 centres from 26 countries reported 1,009 patients aged < 20 yrs. Reported cases per million children (for 5-14 yr olds) were highest in Cyprus (111), Switzerland (47) and Denmark (46). Overall, 57% were males and 48% had situs inversus. Median age at diagnosis was 5.3 yrs, lower in children with situs inversus (3.5 versus 5.8 yrs; p < 0.001) and in children treated in large centres (4.1 versus 4.8 yrs; p = 0.002). Adjusted age at diagnosis was 5.0 yrs in Western Europe, 4.8 yrs in the British Isles, 5.5 yrs in Northern Europe, 6.8 yrs in Eastern Europe and 6.5 yrs in Southern Europe (p < 0.001). This strongly correlated with general government expenditures on health (p < 0.001). This European survey suggests that PCD in children is under-diagnosed and diagnosed late, particularly in countries with low health expenditures. Prospective studies should assess the impact this delay might have on patient prognosis and on health economic costs across Europe.
  •  
7.
  •  
8.
  •  
9.
  •  
10.
  •  
Skapa referenser, mejla, bekava och länka
  • Resultat 1-10 av 10
 
pil uppåt Stäng

Kopiera och spara länken för att återkomma till aktuell vy