415 research outputs found

    Photonic band structure of highly deformable, self-assembling systems

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    We calculate the photonic band structure at normal incidence of highly deformable, self-assembling systems - cholesteric elastomers subjected to external stress. Cholesterics display brilliant reflection and lasing owing to gaps in their photonic band structure. The band structure of cholesteric elastomers varies sensitively with strain, showing new gaps opening up and shifting in frequency. A novel prediction of a total band gap is made, and is expected to occur in the vicinity of the previously observed de Vries bandgap, which is only for one polarisation

    Reversed anisotropies and thermal contraction of FCC (110) surfaces

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    The observed anisotropies of surface vibrations for unreconstructed FCC metal (110) surfaces are often reversed from the "common sense" expectation. The source of these reversals is investigated by performing ab initio density functional theory calculations to obtain the surface force constant tensors for Ag(110), Cu(110) and Al(110). The most striking result is a large enhancement in the coupling between the first and third layers of the relaxed surface, which strongly reduces the amplitude of out-of-plane vibrations of atoms in the first layer. This also provides a simple explanation for the thermal contraction of interlayer distances. Both the anisotropies and the thermal contraction arise primarily as a result of the bond topology, with all three (110) surfaces showing similar behavior.Comment: 13 pages, in revtex format, plus 1 postscript figur

    Educational courses on non-pharmacologic complementary interventions for nurses across Europe : The INES mapping pilot study

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    Funding Information: This study is part of a larger EU-funded project called the Integrative Nursing Education Series (INES). The INES project is a European consortium between the Erasmus Medical Center Rotterdam, the Netherlands; the van Praag Institute, the Netherlands; VIA University College, Denmark; the University of Iceland and Karolinska Institutet, Sweden. The INES consortium aims to strengthen nurses' knowledge, attitudes, competencies and skills on complementary NPIs such as mindfulness, massage and relaxation exercises.This study is part of an EU funded project by Erasmus+ (KA203 Strategic Partnerships for Higher Education): ‘The Integrative Nursing Education Series’ (2019-1-NL01-KA203-060478). Funding Information: This study is part of an EU funded project by Erasmus+ (KA203 Strategic Partnerships for Higher Education): ‘The Integrative Nursing Education Series’ ( 2019-1-NL01-KA203-060478 ). Publisher Copyright: © 2022 The AuthorsBackground: Pharmacological interventions still form the mainstay of the management of pain, anxiety, sleep problems and discomfort. In Europe, an estimated 100 million people use complementary non-pharmacological interventions (NPIs) for these conditions. In their pre-registration education, nurses do not generally learn about the various types of NPIs and how patients and health care professionals can include NPIs complementary to their standard care. Some nursing schools in Europe offer elective courses on NPIs, often relying on individual initiatives. Little is publicly available about the content of these programmes and how they relate to the current nursing curriculum for EU countries. Objectives: This pilot study aims to explore and map the field of nursing education with regard to complementary NPIs for nurses in Europe. Design: A web-based open-access questionnaire administered through the online survey tool LimeSurvey® was designed by the authors. Participants: The questionnaire was sent to a purposive sample of 49 experts on nurse education and complementary NPIs from 16 European countries. All levels of education were eligible for inclusion. Methods: The questionnaire consisted of 35 items regarding course content, teaching material, teaching methods and methods of assessment. In addition, respondents were invited to perform a strengths, weaknesses, opportunities and threats (SWOT) analysis in relation to their education programme. Qualitative data was analyzed using a directive content analysis approach. Results: Between January and May 2020, thirty-one completed questionnaires from ten different countries were returned (response rate 63.3%). Massage, meditation, mindfulness and relaxation are the most taught interventions. Anxiety, stress, chronic pain, depression and sleep problems are the most common symptoms addressed. Conclusions: Currently, a consistent and European approach to education for nurses on complementary NPIs and integrative nursing is lacking. Although taught at regular nursing educational institutes, the courses discussed here are not yet embedded in mainstream education for nurses.Peer reviewe

    Astroparticle Physics with a Customized Low-Background Broad Energy Germanium Detector

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    The MAJORANA Collaboration is building the MAJORANA DEMONSTRATOR, a 60 kg array of high purity germanium detectors housed in an ultra-low background shield at the Sanford Underground Laboratory in Lead, SD. The MAJORANA DEMONSTRATOR will search for neutrinoless double-beta decay of 76Ge while demonstrating the feasibility of a tonne-scale experiment. It may also carry out a dark matter search in the 1-10 GeV/c^2 mass range. We have found that customized Broad Energy Germanium (BEGe) detectors produced by Canberra have several desirable features for a neutrinoless double-beta decay experiment, including low electronic noise, excellent pulse shape analysis capabilities, and simple fabrication. We have deployed a customized BEGe, the MAJORANA Low-Background BEGe at Kimballton (MALBEK), in a low-background cryostat and shield at the Kimballton Underground Research Facility in Virginia. This paper will focus on the detector characteristics and measurements that can be performed with such a radiation detector in a low-background environment.Comment: Submitted to NIMA Proceedings, SORMA XII. 9 pages, 4 figure

    Flux Phase as a Dynamic Jahn-Teller Phase: Berryonic Matter in the Cuprates?

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    There is considerable evidence for some form of charge ordering on the hole-doped stripes in the cuprates, mainly associated with the low-temperature tetragonal phase, but with some evidence for either charge density waves or a flux phase, which is a form of dynamic charge-density wave. These three states form a pseudospin triplet, demonstrating a close connection with the E X e dynamic Jahn-Teller effect, suggesting that the cuprates constitute a form of Berryonic matter. This in turn suggests a new model for the dynamic Jahn-Teller effect as a form of flux phase. A simple model of the Cu-O bond stretching phonons allows an estimate of electron-phonon coupling for these modes, explaining why the half breathing mode softens so much more than the full oxygen breathing mode. The anomalous properties of O2O^{2-} provide a coupling (correlated hopping) which acts to stabilize density wave phases.Comment: Major Revisions: includes comparisons with specific cuprate phonon modes, 16 eps figures, revte

    Prior dengue virus exposure shapes T Cell immunity to Zika Virus in humans

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    While progress has been made in characterizing humoral immunity to Zika virus (ZIKV) in humans, little is known regarding the corresponding T cell responses to ZIKV. Here we investigate the kinetics and viral epitopes targeted by T cells responding to ZIKV and address the critical question of whether pre-existing dengue virus (DENV) T cell immunity modulates these responses. We find that memory T cell responses elicited by prior infection with DENV or vaccination with Tetravalent Dengue Attenuated Vaccines (TDLAV) recognize ZIKV-derived peptides. This cross-reactivity is explained by the sequence similarity of the two viruses, as the ZIKV peptides recognized by DENV-elicited memory T cells are identical or highly conserved in DENV and ZIKV. DENV exposure prior to ZIKV infection also influences the timing and magnitude of the T cell response. ZIKV-reactive T cells in the acute phase of infection are detected earlier and in greater magnitude in DENV-immune patients. Conversely, the frequency of ZIKV-reactive T cells continues to rise in the convalescent phase in DENV-naive donors, but declines in DENV pre-exposed donors, compatible with more efficient control of ZIKV replication and/or clearance of ZIKV antigen. The quality of responses is also influenced by previous DENV exposure, and ZIKV-specific CD8 T cells form DENV pre-exposed donors selectively up-regulated granzyme B and PD1, as compared to DENV-naïve donors. Finally, we discovered that ZIKV structural proteins (E, prM and C) are major targets of both the CD4 and CD8 T cell responses, whereas DENV T cell epitopes are found primarily in nonstructural proteins

    Performance of diagnostic tools for acute cholangitis in patients with suspected biliary obstruction

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    Background Acute cholangitis is an infection requiring endoscopic retrograde cholangiopancreatography (ERCP) and antibiotics. Several diagnostic tools help to diagnose cholangitis. Because diagnostic performance of these tools has not been studied and might therefore impose unnecessary ERCPs, we aimed to evaluate this. Methods We established a nationwide prospective cohort of patients with suspected biliary obstruction who underwent an ERCP. We assessed the diagnostic performance of Tokyo Guidelines (TG18), Dutch Pancreatitis Study Group (DPSG) criteria, and Charcot triad relative to real-world cholangitis as the reference standard. Results 127 (16%) of 794 patients were diagnosed with real-world cholangitis. Using the TG18, DPSG, and Charcot triad, 345 (44%), 55 (7%), and 66 (8%) patients were defined as having cholangitis, respectively. Sensitivity for TG18 was 82% (95% CI 74-88) and specificity 60% (95% CI 56-63). The sensitivity for DPSG and Charcot was 42% (95% CI 33-51) and 46% (95% CI 38-56), specificity was 99.7% (95% CI 99-100) and 99% (95% CI 98-100), respectively. Conclusions TG18 criteria incorrectly diagnoses four out of ten patients with real-world cholangitis, while DPSG and Charcot criteria failed to diagnose more than half of patients. As the cholangitis diagnosis has many consequences for treatment, there is a need for more accurate diagnostic tools or work-up towards ERCP.Cellular mechanisms in basic and clinical gastroenterology and hepatolog

    Long-term quality of life and exocrine and endocrine insufficiency after pancreatic surgery: a multicenter, cross-sectional study

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    Background: Data regarding long-term quality of life and exocrine and endocrine insufficiency after pancreatic surgery for premalignant and benign (non-pancreatitis) disease are lacking. Methods: This cross-sectional study included patients >3 years after pancreatoduodenectomy or left pancreatectomy in six Dutch centers (2006-2016). Outcomes were measured with the EQ-5D-5L, the EORTC QLQ-C30, an exocrine and endocrine pancreatic insufficiency questionnaire, and PAID20. Results: Questionnaires were completed by 153/183 patients (response rate 84%, median follow-up 6.3 years). Surgery related complaints were reported by 72/153 patients (47%) and 13 patients (8.4%) would not undergo this procedure again. The VAS (EQ-5D-5L) was 76 +/- 17 versus 82 +/- 0.4 in the general population (p < 0.001). The mean global health status (QLQ-C30) was 78 +/- 17 versus 78 +/- 17, p = 1.000. Fatigue, insomnia, and diarrhea were clinically relevantly worse in patients. Exocrine pancreatic insufficiency was reported by 62 patients (41%) with relieve of symptoms by enzyme supplementation in 48%. New-onset diabetes mellitus was present in 22 patients (14%). The median PAID20 score was 6.9/20 (IQR 2.5-17.8). Conclusion: Although generic quality of life after pancreatic resection for pre-malignant and benign disease was similar to the general population and diabetes-related distress was low, almost half suffered from a range of symptoms highlighting the need for long-term counseling.Cellular mechanisms in basic and clinical gastroenterology and hepatolog

    The Unitary Gas and its Symmetry Properties

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    The physics of atomic quantum gases is currently taking advantage of a powerful tool, the possibility to fully adjust the interaction strength between atoms using a magnetically controlled Feshbach resonance. For fermions with two internal states, formally two opposite spin states, this allows to prepare long lived strongly interacting three-dimensional gases and to study the BEC-BCS crossover. Of particular interest along the BEC-BCS crossover is the so-called unitary gas, where the atomic interaction potential between the opposite spin states has virtually an infinite scattering length and a zero range. This unitary gas is the main subject of the present chapter: It has fascinating symmetry properties, from a simple scaling invariance, to a more subtle dynamical symmetry in an isotropic harmonic trap, which is linked to a separability of the N-body problem in hyperspherical coordinates. Other analytical results, valid over the whole BEC-BCS crossover, are presented, establishing a connection between three recently measured quantities, the tail of the momentum distribution, the short range part of the pair distribution function and the mean number of closed channel molecules.Comment: 63 pages, 8 figures. Contribution to the Springer Lecture Notes in Physics "BEC-BCS Crossover and the Unitary Fermi gas" edited by Wilhelm Zwerger. Revised version correcting a few typo
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