116 research outputs found

    High-pressure melting curve of hydrogen

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    The melting curve of hydrogen was computed for pressures up to 200 GPa, using molecular dynamics. The inter- and intramolecular interactions were described by the reactive force field (ReaxFF) model. The model describes the pressure-volume equation of state solid hydrogen in good agreement with experiment up to pressures over 150 GPa, however the corresponding equation of state for liquid deviates considerably from density functional theory calculations. Due to this, the computed melting curve, although shares most of the known features, yields considerably lower melting temperatures compared to extrapolations of the available diamond anvil cell data. This failure of the ReaxFF model, which can reproduce many physical and chemical properties (including chemical reactions in hydrocarbons) of solid hydrogen, hints at an important change in the mechanism of interaction of hydrogen molecules in the liquid state

    Relation between smoking history and gene expression profiles in lung adenocarcinomas

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    Background: Lung cancer is the worldwide leading cause of death from cancer. Tobacco usage is the major pathogenic factor, but all lung cancers are not attributable to smoking. Specifically, lung cancer in never-smokers has been suggested to represent a distinct disease entity compared to lung cancer arising in smokers due to differences in etiology, natural history and response to specific treatment regimes. However, the genetic aberrations that differ between smokers and never-smokers' lung carcinomas remain to a large extent unclear. Methods: Unsupervised gene expression analysis of 39 primary lung adenocarcinomas was performed using Illumina HT-12 microarrays. Results from unsupervised analysis were validated in six external adenocarcinoma data sets (n=687), and six data sets comprising normal airway epithelial or normal lung tissue specimens (n=467). Supervised gene expression analysis between smokers and never-smokers were performed in seven adenocarcinoma data sets, and results validated in the six normal data sets. Results: Initial unsupervised analysis of 39 adenocarcinomas identified two subgroups of which one harbored all never-smokers. A generated gene expression signature could subsequently identify never-smokers with 79-100% sensitivity in external adenocarcinoma data sets and with 76-88% sensitivity in the normal materials. A notable fraction of current/former smokers were grouped with never-smokers. Intriguingly, supervised analysis of never-smokers versus smokers in seven adenocarcinoma data sets generated similar results. Overlap in classification between the two approaches was high, indicating that both approaches identify a common set of samples from current/former smokers as potential never-smokers. The gene signature from unsupervised analysis included several genes implicated in lung tumorigenesis, immune-response associated pathways, genes previously associated with smoking, as well as marker genes for alveolar type II pneumocytes, while the best classifier from supervised analysis comprised genes strongly associated with proliferation, but also genes previously associated with smoking. Conclusions: Based on gene expression profiling, we demonstrate that never-smokers can be identified with high sensitivity in both tumor material and normal airway epithelial specimens. Our results indicate that tumors arising in never-smokers, together with a subset of tumors from smokers, represent a distinct entity of lung adenocarcinomas. Taken together, these analyses provide further insight into the transcriptional patterns occurring in lung adenocarcinoma stratified by smoking history

    Modeling the actinides with disordered local moments

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    A first-principles disordered local moment (DLM) picture within the local-spin-density and coherent potential approximations (LSDA+CPA) of the actinides is presented. The parameter free theory gives an accurate description of bond lengths and bulk modulus. The case of δ\delta-Pu is studied in particular and the calculated density of states is compared to data from photo-electron spectroscopy. The relation between the DLM description, the dynamical mean field approach and spin-polarized magnetically ordered modeling is discussed.Comment: 6 pages, 4 figure

    Increased use of cross-sectional imaging for follow-up does not improve post-recurrence survival of surgically treated initially localized R.C.C.: results from a European multicenter database (R.E.C.U.R.).

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    Objective: Modality and frequency of image-based renal cell carcinoma (R.C.C.) follow-up strategies are based on risk of recurrence. Using the R.E.C.U.R.-database, frequency of imaging was studied in regard to prognostic risk groups. Furthermore, it was investigated whether imaging modality utilized in contemporary follow-up were associated with outcome after detection of recurrence. Moreover, outcome was compared based on whether the assessment of potential curability was a pre-defined set of criteria's (per-protocol) or stated by the investigator. Materials and methods: Consecutive non-metastatic R.C.C. patients (n = 1,612) treated with curative intent at 12 institutes across eight European countries between 2006 and 2011 were included. Leibovich or U.I.S.S. risk group, recurrence characteristics, imaging modality, frequency and survival were recorded. Primary endpoints were overall survival (O.S.) after detection of recurrence and frequency of features associated with favourable outcome (non-symptomatic recurrences and detection within the follow-up-programme). Results: Recurrence occurred in 336 patients. Within low, intermediate and high risk for recurrence groups, the frequency of follow-up imaging was highest in the early phase of follow-up and decreased significantly over time (p < 0.001). However, neither the image modality for detection nor ≥ 50% cross-sectional imaging during follow-up were associated with improved O.S. after recurrence. Differences between per protocol and investigator based assessment of curability did not translate into differences in O.S. Conclusions: As expected, the frequency of imaging was highest during early follow-up. Cross-sectional imaging use for detection of recurrences following surgery for localized R.C.C. did not improve O.S. post-recurrence. Prospective studies are needed to determine the value of imaging in follow-up

    Intensive Imaging-based Follow-up of Surgically Treated Localised Renal Cell Carcinoma Does Not Improve Post-recurrence Survival: Results from a European Multicentre Database (RECUR).

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    The optimal follow-up (FU) strategy for patients treated for localised renal cell carcinoma (RCC) remains unclear. Using the RECUR database, we studied imaging intensity utilised in contemporary FU to evaluate its association with outcome after detection of disease recurrence. Consecutive patients with nonmetastatic RCC (n=1612) treated with curative intent at 12 institutes across eight European countries between 2006 and 2011 were included. Recurrence occurred in 336 patients. Cross-sectional (computed tomography, magnetic resonance imaging) and conventional (chest X-ray, ultrasound) methods were used in 47% and 53%, respectively. More intensive FU imaging (more than twofold) than recommended by the European Association of Urology (EAU) was not associated with improved overall survival (OS) after recurrence. Overall, per patient treated for recurrence remaining alive with no evidence of disease, the number of FU images needed was 542, and 697 for high-risk patients. The study results suggest that use of more imaging during FU than that recommended in the 2017 EAU guidelines is unlikely to improve OS after recurrence. Prospective studies are needed to design optimal FU strategies for the future. PATIENT SUMMARY: After curative treatment for localised kidney cancer, follow-up is necessary to detect any recurrence. This study illustrates that increasing the imaging frequency during follow-up, even to double the number of follow-up imaging procedures recommended by the European Association of Urology guidelines, does not translate into improved survival for those with recurrence

    Reproductive and hormonal factors and risk of renal cell carcinoma among women in the European Prospective Investigation into Cancer and Nutrition

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    PurposeThe incidence of small intestinal cancer (SIC) is increasing, however, its aetiology remains unclear due to a lack of data from large-scale prospective cohorts. We examined modifiable risk factors in relation to SIC overall and by histological subtype.MethodsWe analysed 450,107 participants enrolled in the European Prospective Investigation into Cancer and Nutrition cohort. Cox proportional hazards models were used to estimate univariable and multivariable hazard ratios (HRs) and 95% confidence intervals (CIs).ResultsDuring an average of 14.1 years of follow-up, 160 incident SICs (62 carcinoids, 51 adenocarcinomas) were identified. Whilst univariable models revealed a positive association for current versus never smokers and SIC (HR, 95% CI: 1.77, 1.21-2.60), this association attenuated in multivariable models. In energy-adjusted models, there was an inverse association across vegetable intake tertiles for SIC overall (HRT3vsT1, 95% CI: 0.48, 0.32-0.71, p-trend: < 0.001) and for carcinoids (HRT3vsT1, 95% CI: 0.44, 0.24-0.82, p-trend: 0.01); however, these attenuated in multivariable models. Total fat was also inversely associated with total SIC and both subtypes but only in the second tertile (SIC univariable HRT2vsT1, 95% CI: 0.57, 0.38-0.84; SIC multivariable HRT2vsT1, 95% CI: 0.55, 0.37-0.81). Physical activity, intake of alcohol, red or processed meat, dairy products, or fibre were not associated with SIC.ConclusionThese exploratory analyses found limited evidence for a role of modifiable risk factors in SIC aetiology. However, sample size was limited, particularly for histologic subtypes; therefore, larger studies are needed to delineate these associations and robustly identify risk factors for SIC

    Reproductive and hormonal factors and risk of renal cell carcinoma among women in the European Prospective Investigation into Cancer and Nutrition

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    Background - Renal cell carcinoma (RCC) is twice as common among men compared with women, and hormonal factors have been suggested to partially explain this difference. There is currently little evidence on the roles of reproductive and hormonal risk factors in RCC aetiology. Materials & Methods - We investigated associations of age at menarche and age at menopause, pregnancy-related factors, hysterectomy and ovariectomy and exogenous hormone use with RCC risk among 298,042 women in the European Prospective Investigation into Cancer and Nutrition (EPIC) study. Results - During 15 years of follow-up, 438 RCC cases were identified. Parous women had higher rates of RCC compared with nulliparous women (HR = 1.71, 95% CI 1.18, 2.46), and women who were older at age of first pregnancy had lower rates of RCC (30 years + vs. Conclusion - Our results suggest that parity and reproductive organ surgeries may play a role in RCC aetiology

    Neuromusculoskeletal disorders in the neck and upper extremities among drivers of all-terrain vehicles – a case series

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    BACKGROUND: The purpose of this study was to investigate whether professional drivers of all-terrain vehicles (ATVs) with neck pain have a different array of neuromusculoskeletal disorders in the neck and upper extremities than a referent group with neck pain from the general population. It is hypothesized that exposure to shock-type vibration and unfavorable working postures in ATVs have the capacity to cause peripheral nervous lesions. METHODS: This study was based on a case series analyzed according to a case-case comparison design. The study population consisted of 60 male subjects, including professional drivers of forest machines (n = 15), snowmobiles (n = 15), snowgroomers (n = 15) and referents from the general population (n = 15) all of whom had reported neck pain in a questionnaire and underwent an extensive physical examination of the neck and upper extremities. Based on symptom history, symptoms and signs, and in some cases chemical, electroneurographical and radiological findings, subjects were classified as having a nociceptive or neuropathic disorder or a mix of these types. RESULTS: The occurrence of asymmetrical and focal neuropathies (peripheral nervous lesion), pure or in a mix with a nociceptive disorder was common among cases in the ATV driver groups (47%–79%). This contrasted with the referents that were less often classified as having asymmetrical and focal neuropathy (27%), but instead had more nociceptive disorders. The difference was most pronounced among drivers of snowgroomers, while drivers of forest machines were more frequently classified as having a nociceptive disorder originating in the muscles. CONCLUSION: This study found a high prevalence of assymetrical and focal neuropathies among drivers with pain in the neck, operating various ATVs. It seems as if exposure to shock-type whole-body vibration (WBV) and appurtenant unfavorable postures in ATVs may be associated to peripheral nervous lesions
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