620 research outputs found

    Strain induced pressure effect in pulsed laser deposited thin films of the strongly correlated oxide V2O3

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    V2O3 thin films about 10 nm thick were grown on Al2O3 (0001) by pulsed laser deposition. The XRD analysis is in agreement with R-3c space group. Some of them exhibit the metal / insulator transition characteristic of V2O3 bulk material and others samples exhibit a metallic behavior. For the latter, the XPS analysis indicates an oxidation state of +III for vanadium. There is no metal / insulator transition around 150 K in this sample and a strongly correlated Fermi liquid rho = AT2 behavior of the resistivity at low temperature is observed, with a value of A of 1.2 10-4 ohm cm, 3 times larger than the bulk value at 25 kbar

    Tailoring strain in SrTiO3 compound by low energy He+ irradiation

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    The ability to generate a change of the lattice parameter in a near-surface layer of a controllable thickness by ion implantation of strontium titanate is reported here using low energy He+ ions. The induced strain follows a distribution within a typical near-surface layer of 200 nm as obtained from structural analysis. Due to clamping effect from the underlying layer, only perpendicular expansion is observed. Maximum distortions up to 5-7% are obtained with no evidence of amorphisation at fluences of 1E16 He+ ions/cm2 and ion energies in the range 10-30 keV.Comment: 11 pages, 4 figures, Accepted for publication in Europhysics Letter (http://iopscience.iop.org/0295-5075

    Transformation zone location and intraepithelial neoplasia of the cervix uteri.

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    We examined the relationship between the frequency of premalignant lesions of the cervix and location of the transformation zone on the cervix among 8758 women as assessed using cervicography. An endo- and exocervical smear test was performed at the same time. Women with smear test classified CIN I or more were recalled and any abnormal area was biopsied under colposcopy. The transformation zone was located on the exocervix in 94% of women younger than 25 years old; as age increased, the proportion of women with a transformation zone located on the exocervix steadily decreased to reach less than 2% after 64 years old. As compared with women having a transformation zone in the endocervical canal, the age-adjusted likelihood of discovering a histologically proven dysplastic lesion was 1.8 times more frequent among women with a transformation zone located on the exocervix (95% confidence interval 1.1-2.9). This higher frequency seemed not attributable to a lower sensitivity of the smear test when the transformation zone was hidden. The results also showed that deliveries tended significantly to maintain the transformation zone on the exocervix. Parity is a known risk factor for cervix cancer, but the mechanism by which it favours malignant lesions remain unknown. Our results suggest that with increasing numbers of livebirths, the transformation zone is directly exposed for longer periods to external agents involved in dysplastic lesions

    Essential considerations in the investigation of associations between insulin and cancer risk using prescription databases

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    Boyle, P Ford, I Robertson, Jfr La Vecchia, C Boffetta, P Autier, P eng England 2009/01/01 00:00 Ecancermedicalscience. 2009;3:174. doi: 10.3332/ecancer.2009.174. Epub 2009 Dec 11.International audienceno abstrac

    The effect of the systemic inflammatory response on plasma vitamin 25 (OH) D concentrations adjusted for albumin

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    <b>Aim</b><p></p> To examine the relationship between plasma 25(OH)D, CRP and albumin concentrations in two patient cohorts.<p></p> <b>Methods</b><p></p> 5327 patients referred for nutritional assessment and 117 patients with critical illness were examined. Plasma 25 (OH) D concentrations were measured using standard methods. Intra and between assay imprecision was <10%.<p></p> <b>Result</b><p></p> In the large cohort, plasma 25 (OH) D was significantly associated with CRP (rs = −0.113, p<0.001) and albumin (rs = 0.192, p<0.001). 3711 patients had CRP concentrations ≤10 mg/L; with decreasing albumin concentrations ≥35, 25–34 and <25 g/l, median concentrations of 25 (OH) D were significantly lower from 35 to 28 to 14 nmol/l (p<0.001). This decrease was significant when albumin concentrations were reduced between 25–34 g/L (p<0.001) and when albumin <25 g/L (p<0.001). 1271 patients had CRP concentrations between 11–80 mg/L; with decreasing albumin concentrations ≥35, 25–34 and <25 g/l, median concentrations of 25 (OH) D were significantly lower from 31 to 24 to 19 nmol/l (p<0.001). This decrease was significant when albumin concentration were 25–34 g/L (p<0.001) and when albumin <25 g/L (p<0.001). 345 patients had CRP concentrations >80 mg/L; with decreasing albumin concentrations ≥35, 25–34 and <25 g/l, median concentrations of 25 (OH) D were not significantly altered varying from 19 to 23 to 23 nmol/l. Similar relationships were also obtained in the cohort of patients with critical illness.<p></p> <b>Conclusion</b><p></p> Plasma concentrations of 25(OH) D were independently associated with both CRP and albumin and consistent with the systemic inflammatory response as a major confounding factor in determining vitamin D status.<p></p&gt

    Sunscreen use and intentional exposure to ultraviolet A and B radiation: a double blind randomized trial using personal dosimeters

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    A previous randomized trial found that sunscreen use could extend intentional sun exposure, thereby possibly increasing the risk of cutaneous melanoma. In a similarly designed trial, we examined the effect of the use of sunscreens having different sun protection factor (SPF) on actual exposure to ultraviolet B (UVB) and ultraviolet A (UVA) radiation. In June 1998, 58 European participants 18–24 years old were randomized to receive a SPF 10 or 30 sunscreens and were asked to complete daily records of their sun exposure during their summer holidays of whom 44 utilized a personal UVA and UVB dosimeter in a standard way during their sunbathing sessions. The median daily sunbathing duration was 2.4 hours in the SPF 10 group and 3.0 hours in the SPF 30 group (P = 0.054). The increase in daily sunbathing duration was paralleled by an increase in daily UVB exposure, but not by changes in UVA or UVB accumulated over all sunbathing sessions, or in daily UVA exposure. Of all participants, those who used the SPF 30 sunscreen and had no sunburn spent the highest number of hours in sunbathing activities. Differences between the two SPF groups in total number of sunbathing hours, daily sunbathing duration, and daily UVB exposure were largest among participants without sunburn during holidays. Among those with sunburn, the differences between the two groups tended to reduce. In conclusion, sunscreens used during sunbathing tended to increase the duration of exposures to doses of ultraviolet radiation below the sunburn threshold. © 2000 Cancer Research Campaig

    Observed and predicted risk of breast cancer death in randomized trials on breast cancer screening

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    BACKGROUND: The role of breast screening in breast cancer mortality declines is debated. Screening impacts cancer mortality through decreasing the number of advanced cancers with poor diagnosis, while cancer treatment works through decreasing the case-fatality rate. Hence, reductions in cancer death rates thanks to screening should directly reflect reductions in advanced cancer rates. We verified whether in breast screening trials, the observed reductions in the risk of breast cancer death could be predicted from reductions of advanced breast cancer rates. PATIENTS AND METHODS: The Greater New York Health Insurance Plan trial (HIP) is the only breast screening trial that reported stage-specific cancer fatality for the screening and for the control group separately. The Swedish Two-County trial (TCT)) reported size-specific fatalities for cancer patients in both screening and control groups. We computed predicted numbers of breast cancer deaths, from which we calculated predicted relative risks (RR) and (95% confidence intervals). The Age trial in England performed its own calculations of predicted relative risk. RESULTS: The observed and predicted RR of breast cancer death were 0.72 (0.56-0.94) and 0.98 (0.77-1.24) in the HIP trial, and 0.79 (0.78-1.01) and 0.90 (0.80-1.01) in the Age trial. In the TCT, the observed RR was 0.73 (0.62-0.87), while the predicted RR was 0.89 (0.75-1.05) if overdiagnosis was assumed to be negligible and 0.83 (0.70-0.97) if extra cancers were excluded. CONCLUSIONS: In breast screening trials, factors other than screening have contributed to reductions in the risk of breast cancer death most probably by reducing the fatality of advanced cancers in screening groups. These factors were the better management of breast cancer patients and the underreporting of breast cancer as the underlying cause of death. Breast screening trials should publish stage-specific fatalities observed in each group
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