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We present an implementation of a damped response framework for calculating resonant inelastic X-ray scattering (RIXS) at the equation-of-motion coupled-cluster singles and doubles (CCSD) and second-order approximate coupled-cluster singles and doubles (CC2) levels of theory in the open-source program eT. This framework lays the foundation for future extension to higher excitation methods (notably, the coupled-cluster singles and doubles with perturbative triples, CC3) and to multilevel approaches. Our implementation adopts a fully relaxed ground state and different variants of the core-valence separation projection technique to address convergence issues. Illustrative results are compared with those obtained within the frozen-core core-valence separated approach, available in Q-Chem, as well as with experiment. The performance of the CC2 method is evaluated in comparison with that of CCSD. It is found that, while the CC2 method is noticeably inferior to CCSD for X-ray absorption spectra, the quality of the CC2 RIXS spectra is often comparable to that of the CCSD level of theory, when the same valence excited states are probed. Finally, we present preliminary RIXS results for a solvated molecule in aqueous solution.
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We present an efficient implementation of ground and excited state coupled cluster singles and doubles (CCSD) gradients based on Cholesky-decomposed electron repulsion integrals. Cholesky decomposition and density fitting are both inner projection methods, and, thus, similar implementation schemes can be applied for both methods. One well-known advantage of inner projection methods, which we exploit in our implementation, is that one can avoid storing large V3O and V4 arrays by instead considering three-index intermediates. Furthermore, our implementation does not require the formation and storage of Cholesky vector derivatives. The new implementation is shown to perform well, with less than 10% of the time spent calculating the gradients in geometry optimizations. Furthermore, the computational time per optimization cycle is significantly lower compared to other implementations based on an inner projection method. We showcase the capabilities of the implementation by optimizing the geometry of the retinal molecule (C20H28O) at the CCSD/aug-cc-pVDZ level of theory.
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We have measured, analyzed, and simulated the ground state valence photoelectron spectrum, x-ray absorption (XA) spectrum, x-ray photoelectron (XP) spectrum as well as normal and resonant Auger-Meitner electron (AE) spectrum of oxazole at the carbon, oxygen, and nitrogen K-edge in order to understand its electronic structure. Experimental data are compared to theoretical calculations performed at the coupled cluster, restricted active space perturbation theory to second-order and time-dependent density functional levels of theory. We demonstrate (1) that both N and O K-edge XA spectra are sensitive to the amount of dynamical electron correlation included in the theoretical description and (2) that for a complete description of XP spectra, additional orbital correlation and orbital relaxation effects need to be considered. The normal AE spectra are dominated by a singlet excitation channel and well described by theory. The resonant AE spectra, however, are more complicated. While the participator decay channels, dominating at higher kinetic energies, are well described by coupled cluster theory, spectator channels can only be described satisfactorily using a method that combines restricted active space perturbation theory to second order for the bound part and a one-center approximation for the continuum.
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A theoretical framework for understanding molecular structures is crucial for the development of new technologies such as catalysts or solar cells. Apart from electronic excitation energies, however, only spectroscopic properties of molecules consisting of lighter elements can be computationally described at a high level of theory today since heavy elements require a relativistic framework, and thus far, most methods have only been derived in a non-relativistic framework. Important new technologies such as those mentioned above require molecules that contain heavier elements, and hence, there is a great need for the development of relativistic computational methods at a higher level of accuracy. Here, the Second-Order-Polarization-Propagator-Approximation (SOPPA), which has proven to be very successful in the non-relativistic case, is adapted to a relativistic framework. The equations for SOPPA are presented in their most general form, i.e., in a non-canonical spin-orbital basis, which can be reduced to the canonical case, and the expressions needed for a relativistic four-component SOPPA are obtained. The equations are one-index transformed, giving more compact expressions that correspond to those already available for the four-component RPA. The equations are ready for implementation in a four-component quantum chemistry program, which will allow both linear response properties and excitation energies to be calculated relativistically at the SOPPA level.
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In this article, the RPA(D) and HRPA(D) models for the calculation of linear response functions are presented. The performance of the new RPA(D) and HRPA(D) models is compared to the performance of the established RPA, HRPA, and SOPPA models in calculations of indirect nuclear spin-spin coupling constants using the CCSD model as a reference. The doubles correction offers a significant improvement on both the RPA and HRPA models; however, the improvement is more dramatic in the case of the RPA model. For all coupling types investigated in this study, the results obtained using the HRPA(D) model are comparable in accuracy to those given by the SOPPA model, while requiring between 30% and 90% of the calculation time needed for SOPPA. The RPA(D) model, while of slightly lower accuracy compared to the CCSD model than HRPA(D), offered calculation times of only approximately 25% of those required for SOPPA for all the investigated molecules. © 2018 Wiley Periodicals, Inc.
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MAIN CONCLUSION: Ripening initiation-associated hormonal changes and sugar accumulation for individual fruits differed by seed content and did not depend heavily on flowering time or duration from anthesis to clusters' onset of ripening. For Vitis vinifera, the ripening initiation of individual fruits in a cluster occurs unevenly. This developmental period is called véraison. Why individual fruits initiate ripening at different times is not well studied, though differences in seed content and unequal developmental durations that arise from asynchronous flowering within a cluster have been proposed. This study examined how much both variables contribute to individual fruits' ripening progress by mid-véraison, when half of berries in a cluster have initiated ripening, and whether either or both factors affect the timing of characteristic, ripening-initiation associated changes in abscisic acid and auxin before, at, and after véraison. Overall, developmental duration and flowering time did not sufficiently explain how far berries had progressed into the ripening stage because fruits did not require a fixed amount of time to initiate ripening. Fruits from early and late flowers but of similar seed content were able to initiate ripening at the same time despite differences in chronological age. This suggests either an early developmental enhancement occurred for late-initiated fruits or that flowering time is an inappropriate "day zero". Ultimately, only seed content was linked to the timing and magnitude of ripening-related hormone changes, supporting that seeds have a comparatively larger influence than flowering time on the ripening initiation of individual berries. More specifically, if the fraction of berry weight occupied by seed was high, then the initiation of ripening for that berry and its associated hormone changes were delayed relative to berries with less seed weight versus total berry weight.
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Flores/fisiología , Frutas/fisiología , Semillas/metabolismo , Vitis/fisiología , Ácido Abscísico/metabolismo , Frutas/crecimiento & desarrollo , Ácidos Indolacéticos/metabolismo , Modelos Biológicos , Monosacáridos/metabolismo , Oregon , Reguladores del Crecimiento de las Plantas/metabolismo , Semillas/química , Semillas/crecimiento & desarrollo , Vitis/crecimiento & desarrolloRESUMEN
Introduction: Sepsis is a life-threatening and common cause of Emergency department (ED) referrals. Out-of-hour staffing is limited in ED, which may potentially affect fluid administration. This study aimed to investigate fluid volume variation in out-of-hour vs. routine-hour admissions. Methods: The present study is a post-hoc analysis of a multicentre, prospective, observational study investigating fluid administration in ED patients with suspected infection, from Jan 20th - March 2nd, 2020. Patient groups were "routine-hours" (RH): weekdays 07:00-18:59 or "out-of-hours" (OOH): weekdays 19:00-06:59 or Friday 19:00-Monday 06:59. Primary outcome was 24-hour total fluid volumes (oral + intravenous (IV)). Secondary outcomes were total fluids 0-6 hours, oral fluids 0-6 and 0-24 hours, and IV fluids 0-6 and 0-24 hours. Linear regression adjusted for site and illness severity was used. Results: 734 patients had suspected infection; 449 were admitted during RH and 287 during OOH. Mean (95% CI) total 24-hour fluid volumes were equal in simple infection and sepsis regardless of admission time: Simple infection RH: 3640 (3410 - 3871) ml and OOH: 3681 (3451 - 3913) ml. Sepsis RH: 3671 (3443;3898) ml and OOH: 3896 (3542;4250) ml. Oral fluids 0-6h were reduced in simple infection and sepsis among OOH vs. RH. Sepsis patients received more 0-6-hour IV fluid when admitted OOH vs. RH. There were no associations between admission time and 0-24-hour oral or IV volumes in simple infection or sepsis. Conclusion: Admission time did not have an association with 24-hour total fluid volumes. Sepsis patients admitted during OOH received more 0-6-hour IV fluids than RH patients, and simple infection and sepsis patients received less oral fluid in 0-6 hours if admitted during OOH vs. RH.
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Background: Although approximately 41% of women experience sexual dysfunction, limited education on female sexual medicine (FSM) in medical school results in underpreparedness among physicians when addressing these bothersome conditions. Aim: This study aims to evaluate the extent to which FSM is represented in medical education by examining current preclinical and clinical curricula. Methods: Preclinical curriculum materials on female sexual anatomy, physiology, and pathology, as well as obstetrics and gynecology clinical materials (syllabi, lecture materials, and supplemental resources), were collected from medical schools in the Chicago area. We utilized previous literature to identify specific components of medical school content to evaluate. Outcomes: Upon reviewing each institution's curricula, we evaluated materials for topic saturation and assessed goals of each syllabus in terms of required content. Results: Curriculum materials were collected from 7 medical schools. In the preclinical assessment, 1 institution identified all anatomic components of the clitoris in our review, 4 discussed the physiology of the female orgasm, 3 highlighted the prevalence and epidemiology of female sexual dysfunction (FSD), 3 addressed treatments for FSD, and 1 instructed a genitourinary physical exam specific to assessing FSD. When assessing obstetrics and gynecology clinical materials, 5 institutions included topics related to FSM. Of these, only 1 institution had corresponding required synchronous clerkship time dedicated to these topics as a 1-hour lecture, in addition to an optional online training to third-year clinical students in comprehensive sexual history-taking practices, including screening for FSD. One other institution offered supplemental case-based gynecology modules including vulvovaginal diseases and chronic pelvic pain, though sexual pleasure, arousal, and libido were not included. Clinical Implications: The results of this study highlight the need for the inclusion of standardized curricula related to FSM in medical education to equip future physicians to treat patients with sexual dysfunction. Strengths and Limitations: The strengths of this study include that it is the first of its kind to complete a comprehensive review of FSM curricula at a cohort of undergraduate medical institutions. Its limitations include a small sample size of 7 medical schools limited to 1 geographical area. Conclusion: Our focused needs assessment of medical schools in the Chicago area reveals inconsistencies in outlined institution-specific course goals related to FSM and thus highlights the need for restructuring the curricula to prepare future physicians to recognize and treat patients with sexual dysfunction.
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The time-resolved x-ray absorption spectrum of the BT-1T cation (BT-1T+) is theoretically simulated in order to investigate the charge transfer reaction of the system. We employ both trajectory surface hopping and quantum dynamics to simulate the structural evolution over time and the changes in the state populations. To compute the static x-ray absorption spectra (XAS) of the ground and excited states, we apply both the time-dependent density functional theory and the coupled cluster singles and doubles method. The results obtained are in good agreement between the methods. It is, furthermore, found that the small structural changes that occur during the reaction have little effect on the static XAS. Hence, the tr-XAS can be computed based on the state populations determined from a nuclear dynamics simulation and one set of static XAS calculations, utilizing the ground state optimized geometry. This approach can save considerable computational resources, as the static spectra need not to be calculated for all geometries. As BT-1T is a relatively rigid molecule, the outlined approach should only be considered when investigating non-radiative decay processes in the vicinity of the Franck-Condon point.
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OBJECTIVE: To summarize an innovative initiative in oncology nurse workforce development that addresses critical current and future gaps and encompasses use of dedicated education units for student nurse rotation and a transition-to-practice residency program. DATA SOURCES: Review of institutional data including original pilot analysis and ongoing programmatic metrics (N=8 years), consensus, professional guidelines, and published literature. CONCLUSION: The dedicated education unit serves as a conduit for recruitment into institutional oncology nurse residency positions, and retention rates in the residency program continue to exceed national averages. Subsequent mentoring of these nurses in transition to practice has manifested high rates of promotion into nurse leadership roles year over year. IMPLICATIONS FOR NURSING PRACTICE: Oncology nurse practice incorporates state-of-the-science approved therapies, early phase clinical trial implementation, and evidence-based complex oncology patient care management. A new model of student clinical nurse rotations in ambulatory settings, nurse resident transition to practice, and ongoing leadership mentoring is essential in creating a sustainable, highly skilled, and robust oncology nurse work force.
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Educación en Enfermería/organización & administración , Enfermería Oncológica/educación , Preceptoría/organización & administración , Recursos Humanos , Atención Ambulatoria/organización & administración , Competencia Clínica , Humanos , Rol de la Enfermera , Investigación en Evaluación de EnfermeríaRESUMEN
BACKGROUND: Low physical activity level is associated with poor prognosis in patients with colorectal cancer (CRC). To increase physical activity, technology-based platforms are emerging and provide intriguing opportunities to prescribe and monitor active lifestyle interventions. The "Interval Walking in Colorectal Cancer"(I-WALK-CRC) study explores the feasibility and efficacy a home-based interval-walking intervention delivered by a smart-phone application in order to improve cardio-metabolic health profile among CRC survivors. The aim of the present report is to describe the design, methods and recruitment results of the I-WALK-CRC study.Methods/Results: The I-WALK-CRC study is a randomized controlled trial designed to evaluate the feasibility and efficacy of a home-based interval walking intervention compared to a waiting-list control group for physiological and patient-reported outcomes. Patients who had completed surgery for local stage disease and patients who had completed surgery and any adjuvant chemotherapy for locally advanced stage disease were eligible for inclusion. Between October 1st, 2015, and February 1st, 2017, 136 inquiries were recorded; 83 patients were eligible for enrollment, and 42 patients accepted participation. Age and employment status were associated with participation, as participants were significantly younger (60.5 vs 70.8 years, Pâ¯<â¯0.001) and more likely to be working (OR 5.04; 95%CI 1.96-12.98, Pâ¯<â¯0.001) than non-participants. CONCLUSION: In the present study, recruitment of CRC survivors was feasible but we aim to better the recruitment rate in future studies. Further, the study clearly favored younger participants. The I-WALK-CRC study will provide important information regarding feasibility and efficacy of a home-based walking exercise program in CRC survivors.