292 research outputs found

    Core hole-electron correlation in coherently coupled molecules

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    We study the core hole-electron correlation in coherently coupled molecules by energy dispersive near edge X-ray absorption fine-structure spectroscopy. In a transient phase, which exists during the transition between two bulk arrangements, 1,4,5,8-naphthalene-tetracarboxylicacid-dianhydride multilayer films exhibit peculiar changes of the line shape and energy position of the X-ray absorption signal at the C K-edge with respect to the bulk and gas phase spectra. By a comparison to a theoretical model based on a coupling of transition dipoles, which is established for optical absorption, we demonstrate that the observed spectroscopic differences can be explained by an intermolecular delocalized core hole-electron pair. By applying this model we can furthermore quantify the coherence length of the delocalized core-exciton.Comment: 5 pages, 3 figures, Accepted Version, PRL, minor wording change

    Proteomics uncover EPHA2 as a potential novel therapeutic target in colorectal cancer cell lines with acquired cetuximab resistance.

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    BACKGROUND: In metastatic colorectal cancer (mCRC), acquired resistance against anti-EGFR targeted monoclonal antibodies, such as cetuximab (CET), was shown to be frequently caused by activating alterations in the RAS genes KRAS or NRAS. To this day, no efficient follow-up treatment option has emerged to treat mCRC in such a setting of resistance. METHODS: To uncover potential targets for second-line targeted therapies, we used mass-spectrometric proteomics to shed light on kinome reprogramming in an established cellular model of acquired, KRAS-associated CET resistance. RESULTS: This CET resistance was reflected by significant changes in the kinome, most of them individual to each cell line. Interestingly, all investigated resistant cell lines displayed upregulation of the Ephrin type-A receptor 2 (EPHA2), a well-known driver of traits of progression. Expectedly resistant cell lines displayed increased migration (p < 0.01) that was significantly reduced by targeting the EPHA2 signalling axis using RNA interference (RNAi) (p < 0.001), ephrin-A1 stimulation (p < 0.001), dasatinib (p < 0.01), or anti-EPHA2 antibody treatment (p < 0.001), identifying it as an actionable target in mCRC with acquired CET resistance. CONCLUSION: These results highlight EPHA2 and its role in mCRC with KRAS-gene mutated acquired CET resistance and support its use as a potential actionable target for the development of future precision medicine therapies

    Patients' views of routine quality of life assessment following a diagnosis of early-stage non-small cell lung cancer.

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    OBJECTIVES: There is an increasing interest in the quality of life (QoL) evaluation following video-assisted thoracoscopic anatomical lung resection or stereotactic ablative body radiotherapy for early-stage non-small-cell lung cancer (NSCLC). A qualitative interview study was conducted to gain insight into the optimal methods of assessing and discussing QoL in clinical practice. METHODS: A prospective observational longitudinal study of patients with early-stage NSCLC was conducted where repeated QoL measures were administered either online or on paper. A subset of participants was invited for qualitative interviews after the 6-month assessment or at the end of the study. The semi-structured interviews were transcribed verbatim and thematically analysed. RESULTS: Twenty-three patients were interviewed. Generally, patients were content with recruitment and data collection procedures. Most opted to complete the assessments on paper instead of online; this choice was influenced by the level of technology literacy. Some found the questionnaires too generic to reflect their experiences. Barriers to questionnaire completion were mostly practical, and many acknowledged benefits of QoL assessment including allowing them to express problems and health issues, and following changes over time. Generally, participants would like to discuss QoL results during clinical consultations, but reported this rarely happened. CONCLUSIONS: Lung cancer patient interviews confirm the acceptability of repeated QoL assessments, but online data capture is limited. Patients highlight the importance of discussing QoL aspects with their clinical team. Future strategies are needed to optimize the routine collection of patient-reported outcomes in clinical practice

    Electronic Patient Reporting of Adverse Events and Quality of Life: A Prospective Feasibility Study in General Oncology

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    PURPOSE: Adverse event (AE) reporting is essential in clinical trials. Clinician interpretation can result in under-reporting; therefore, the value of patient self-reporting has been recognized. The National Cancer Institute has developed a Patient-Reported Outcomes version of the Common Terminology Criteria for Adverse Events (PRO-CTCAE) for direct patient AE reporting. A nonrandomized prospective cohort feasibility study aimed to explore the compliance and acceptability of an electronic (Internet or telephone) system for collecting patient self-reported AEs and quality of life (QOL). METHODS: Oncology patients undergoing treatment (chemotherapy, targeted agents, hormone therapy, radiotherapy, and/or surgery) at 2 hospitals were sent automated weekly reminders to complete PRO-CTCAE once a week and QOL (for a maximum of 12 weeks). Patients had to speak/understand English and have access to the Internet or a touch-tone telephone. Primary outcome was compliance (proportion of expected questionnaires), and recruitment rate, attrition, and patient/staff feedback were also explored. RESULTS: Of 520 patients, 249 consented (47.9%)—mean age was 62 years, 51% were male, and 70% were married—and 230 remained on the study at week 12. PRO-CTCAE was completed at 2,301 (74.9%) of 3,074 timepoints and QOL at 749 (79.1%) of 947 timepoints. Individual weekly/once every 4 weeks compliance reduced over time but was more than 60% throughout. Of 230 patients, 106 (46.1%) completed 13 or more PRO-CTCAE, and 136 (59.1%) of 230 patients completed 4 QOL questionnaires. Most were completed on the Internet (82.3%; mean age, 60.8 years), which was quicker, but older patients preferred the telephone option (mean age, 70.0 years). Positive feedback was received from patients and staff. CONCLUSION: Self-reporting of AEs and QOL using an electronic home-based system is feasible and acceptable. Implementation of this approach in cancer clinical trials may improve the precision and accuracy of AE reporting

    Electronic patient self-Reporting of Adverse-events: Patient Information and aDvice (eRAPID): a randomised controlled trial in systemic cancer treatment

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    BACKGROUND: eRAPID (electronic patient self-Reporting of Adverse-events: Patient Information and aDvice) is an internet based system for patients to self-report symptoms and side effects (adverse events or AE) of cancer treatments. eRAPID allows AE reporting from home and patient reported data is accessible via Electronic Patient Records (EPR) for use in routine care. The system can generate alerts to clinical teams for severe AE and provides patient advice on managing mild AEs. The overall aims of eRAPID are to improve the safe delivery of cancer treatments, enhance patient care and standardise AE documentation. METHODS: The trial is a prospective randomised two-arm parallel group design study with repeated measures and mixed methods. Participants (adult patients with breast cancer on neo-adjuvant or adjuvant chemotherapy, colorectal and gynaecological cancer receiving chemotherapy) are randomised to receive the eRAPID intervention or usual care over 18 weeks of treatment. Participants in the intervention arm receive training in using the eRAPID system to provide routine weekly adverse event reports from home. Hospital staff can access eRAPID reports via the EPR and use the information during consultations or phone calls with patients. Prior to commencing the full trial an internal pilot phase was conducted (N = 87 participants) to assess recruitment procedures, consent and attrition rates, the integrity of the intervention information technology and establish procedures for collecting outcome data. The overall target sample for the trial is N = 504. The primary outcome of the trial is quality of life (FACT-G) with secondary outcomes including health economics (costs to patients and the NHS), process of care (e.g. contacts with the hospital, number of admissions, clinic appointments and changes to treatment/medications) and patient self-efficacy. Outcome data is collected at baseline, 6, 12, 18 weeks and 12 months. The intervention is also being evaluated via end of study interviews with patient participants and clinical staff. DISCUSSION: The pilot phase was completed in February 2016 and recruitment and attrition rates met criteria for continuing to the full trial. Recruitment recommenced in May 2016 and is planned to continue until December 2017. Overall findings will determine the value of the eRAPID intervention for supporting the care of patients receiving systemic cancer treatment. TRIAL REGISTRATION: Current Controlled Trials ISRCTN88520246 . Registered 11 September 2014

    Detection of variable VHE gamma-ray emission from the extra-galactic gamma-ray binary LMC P3

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    Context. Recently, the high-energy (HE, 0.1-100 GeV) Îł\gamma-ray emission from the object LMC P3 in the Large Magellanic Cloud (LMC) has been discovered to be modulated with a 10.3-day period, making it the first extra-galactic Îł\gamma-ray binary. Aims. This work aims at the detection of very-high-energy (VHE, >100 GeV) Îł\gamma-ray emission and the search for modulation of the VHE signal with the orbital period of the binary system. Methods. LMC P3 has been observed with the High Energy Stereoscopic System (H.E.S.S.); the acceptance-corrected exposure time is 100 h. The data set has been folded with the known orbital period of the system in order to test for variability of the emission. Energy spectra are obtained for the orbit-averaged data set, and for the orbital phase bin around the VHE maximum. Results. VHE Îł\gamma-ray emission is detected with a statistical significance of 6.4 σ\sigma. The data clearly show variability which is phase-locked to the orbital period of the system. Periodicity cannot be deduced from the H.E.S.S. data set alone. The orbit-averaged luminosity in the 1−101-10 TeV energy range is (1.4±0.2)×1035(1.4 \pm 0.2) \times 10^{35} erg/s. A luminosity of (5±1)×1035(5 \pm 1) \times 10^{35} erg/s is reached during 20% of the orbit. HE and VHE Îł\gamma-ray emissions are anti-correlated. LMC P3 is the most luminous Îł\gamma-ray binary known so far.Comment: 5 pages, 3 figures, 1 table, accepted for publication in A&

    Search for dark matter annihilation signals in the H.E.S.S. Inner galaxy survey

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    The central region of the Milky Way is one of the foremost locations to look for dark matter (DM) signatures. We report the first results on a search for DM particle annihilation signals using new observations from an unprecedented Îł-ray survey of the Galactic Center (GC) region, i.e., the Inner Galaxy Survey, at very high energies (≳100  GeV) performed with the H.E.S.S. array of five ground-based Cherenkov telescopes. No significant Îł-ray excess is found in the search region of the 2014-2020 dataset and a profile likelihood ratio analysis is carried out to set exclusion limits on the annihilation cross section ⟚σv⟩. Assuming Einasto and Navarro-Frenk-White (NFW) DM density profiles at the GC, these constraints are the strongest obtained so far in the TeV DM mass range. For the Einasto profile, the constraints reach ⟚σv⟩ values of 3.7×10^{-26}  cm^{3} s^{-1} for 1.5 TeV DM mass in the W^{+}W^{-} annihilation channel, and 1.2×10^{-26}  cm^{3} s^{-1} for 0.7 TeV DM mass in the τ^{+}τ^{-} annihilation channel. With the H.E.S.S. Inner Galaxy Survey, ground-based Îł-ray observations thus probe ⟚σv⟩ values expected from thermal-relic annihilating TeV DM particles

    A deep spectromorphological study of the Îł -ray emission surrounding the young massive stellar cluster Westerlund 1

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    Context. Young massive stellar clusters are extreme environments and potentially provide the means for efficient particle acceleration. Indeed, they are increasingly considered as being responsible for a significant fraction of cosmic rays (CRs) that are accelerated within the Milky Way. Westerlund 1, the most massive known young stellar cluster in our Galaxy, is a prime candidate for studying this hypothesis. While the very-high-energy Îł-ray source HESS J1646-458 has been detected in the vicinity of Westerlund 1 in the past, its association could not be firmly identified. Aims. We aim to identify the physical processes responsible for the Îł-ray emission around Westerlund 1 and thus to understand the role of massive stellar clusters in the acceleration of Galactic CRs better. Methods. Using 164 h of data recorded with the High Energy Stereoscopic System (H.E.S.S.), we carried out a deep spectromorphological study of the Îł-ray emission of HESS J1646-458. We furthermore employed H I and CO observations of the region to infer the presence of gas that could serve as target material for interactions of accelerated CRs. Results. We detected large-scale (~2 diameter) Îł-ray emission with a complex morphology, exhibiting a shell-like structure and showing no significant variation with Îł-ray energy. The combined energy spectrum of the emission extends to several tens of TeV, and it is uniform across the entire source region. We did not find a clear correlation of the Îł-ray emission with gas clouds as identified through H I and CO observations. Conclusions. We conclude that, of the known objects within the region, only Westerlund 1 can explain the majority of the Îł-ray emission. Several CR acceleration sites and mechanisms are conceivable and discussed in detail. While it seems clear that Westerlund 1 acts as a powerful particle accelerator, no firm conclusions on the contribution of massive stellar clusters to the flux of Galactic CRs in general can be drawn at this point

    Preliminary evidence on the uptake, use and benefits of the CONSORT-PRO extension.

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    PURPOSE: This study assessed the uptake of the CONsolidated Standards of Reporting Trials (CONSORT)-Patient-Reported Outcomes (PRO) statement; determined if use of CONSORT-PRO was associated with more complete reporting of PRO endpoints in randomised controlled trials (RCTs) and identified the extent to which high-impact journals publishing RCTs with PRO endpoints endorse CONSORT-PRO. METHODS: CONSORT-PRO citations were identified by systematically searching Medline, EMBASE and Google from 2013 (year CONSORT-PRO released) to 17 December 2015. RCTs that cited CONSORT-PRO (cases) were compared to a comparable control sample of RCTs in terms of adherence to CONSORT-PRO using t tests. General linear models assessed the relationship between CONSORT-PRO score and key, pre-specified variables. The 100 highest-impact journals that published RCTs with PRO endpoints (2014-2015) were identified via a systematic Medline search. Instructions for authors were reviewed to determine whether journals endorsed CONSORT-PRO. RESULTS: Total CONSORT-PRO scores ranged from 47 to 100% for cases and 25-96% for controls. Cases had significantly higher total CONSORT-PRO scores compared to controls: t = 2.64, p = 0.01. 'Citing CONSORT-PRO', 'journal endorsing CONSORT-PRO' and 'dedicated PRO paper' were significant predictors of higher CONSORT-PRO adherence score: R (2) = 0.48, p < 0.001. 11/100 top-ranked journals endorsed CONSORT-PRO in their instructions to authors, seven of these journals published RCTs included as cases in this study. CONCLUSION: This study demonstrated improved PRO reporting associated with journal endorsement and author use of the CONSORT-PRO extension. Despite growing awareness, more work is needed to promote appropriate use of CONSORT-PRO to improve completeness of reporting; in particular, stronger journal endorsement of CONSORT-PRO

    Adaptive Evolution of Escherichia coli to an α-Peptide/ÎČ-Peptoid Peptidomimetic Induces Stable Resistance.

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    Antimicrobial peptides (AMPs) and synthetic analogues thereof target conserved structures of bacterial cell envelopes and hence, development of resistance has been considered an unlikely event. However, recently bacterial resistance to AMPs has been observed, and the aim of the present study was to determine whether bacterial resistance may also evolve against synthetic AMP analogues, e.g. α-peptide/ÎČ-peptoid peptidomimetics. E. coli ATCC 25922 was exposed to increasing concentrations of a peptidomimetic (10 lineages), polymyxin B (10 lineages), or MilliQ water (4 lineages) in a re-inoculation culturing setup covering approx. 500 generations. All 10 lineages exposed to the peptidomimetic adapted to 32 × MIC while this occurred for 8 out of 10 of the polymyxin B-exposed lineages. All lineages exposed to 32 × MIC of either the peptidomimetic or polymyxin B had a significantly increased MIC (16-32 ×) to the selection agent. Five transfers (≈ 35 generations) in unsupplemented media did not abolish resistance indicating that resistance was heritable. Single isolates from peptidomimetic-exposed lineage populations displayed MICs against the peptidomimetic from wild-type MIC to 32 × MIC revealing heterogeneous populations. Resistant isolates showed no cross-resistance against a panel of membrane-active AMPs. These isolates were highly susceptible to blood plasma antibacterial activity and were killed when plasma concentrations exceeded ≈ 30%. Notably, MIC of the peptidomimetic against resistant isolates returned to wild-type level upon addition of 25% plasma. Whole-genome sequencing of twenty isolates from four resistant lineages revealed mutations, in murein transglycosylase D (mltD) and outer-membrane proteins, which were conserved within and between lineages. However, no common resistance-conferring mutation was identified. We hypothesise that alterations in cell envelope structure result in peptidomimetic resistance, and that this may occur via several distinct mechanisms. Interestingly, this type of resistance result in a concomitant high susceptibility towards plasma, and therefore the present study does not infer additional concern for peptidomimetics as future therapeutics
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