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X-ray resonant Raman spectroscopy (XRRS), a variant of resonant inelastic x-ray scattering, has been used to investigate the two prototype systems, UF4and UO2. Both are U5f2and each is an example of 5f localized, ionic behavior and 5f localized, covalent behavior, respectively. From the M5XRRS measurements, the 5f band gap in each can be directly determined and, moreover, a clear and powerful sensitivity to 5f covalency emerges.
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When a heavy atomic nucleus splits (fission), the resulting fragments are observed to emerge spinning1; this phenomenon has been a mystery in nuclear physics for over 40 years2,3. The internal generation of typically six or seven units of angular momentum in each fragment is particularly puzzling for systems that start with zero, or almost zero, spin. There are currently no experimental observations that enable decisive discrimination between the many competing theories for the mechanism that generates the angular momentum4-12. Nevertheless, the consensus is that excitation of collective vibrational modes generates the intrinsic spin before the nucleus splits (pre-scission). Here we show that there is no significant correlation between the spins of the fragment partners, which leads us to conclude that angular momentum in fission is actually generated after the nucleus splits (post-scission). We present comprehensive data showing that the average spin is strongly mass-dependent, varying in saw-tooth distributions. We observe no notable dependence of fragment spin on the mass or charge of the partner nucleus, confirming the uncorrelated post-scission nature of the spin mechanism. To explain these observations, we propose that the collective motion of nucleons in the ruptured neck of the fissioning system generates two independent torques, analogous to the snapping of an elastic band. A parameterization based on occupation of angular momentum states according to statistical theory describes the full range of experimental data well. This insight into the role of spin in nuclear fission is not only important for the fundamental understanding and theoretical description of fission, but also has consequences for the γ-ray heating problem in nuclear reactors13,14, for the study of the structure of neutron-rich isotopes15,16, and for the synthesis and stability of super-heavy elements17,18.
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An amendment to this paper has been published and can be accessed via a link at the top of the paper.
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Personas con Mala Vivienda/historia , Administración en Salud Pública/historia , Determinantes Sociales de la Salud/historia , Recolección de Datos , Objetivos , Historia del Siglo XIX , Atención Dirigida al Paciente/historia , Atención Dirigida al Paciente/organización & administración , Desarrollo SostenibleRESUMEN
We present a high energy resolution x-ray spectrometer for the tender x-ray regime (1.6-5.0 keV) that was designed and operated at Stanford Synchrotron Radiation Lightsource. The instrument is developed on a Rowland geometry (500 mm of radius) using cylindrically bent Johansson analyzers and a position sensitive detector. By placing the sample inside the Rowland circle, the spectrometer operates in an energy-dispersive mode with a subnatural line-width energy resolution (â¼0.32 eV at 2400 eV), even when an extended incident x-ray beam is used across a wide range of diffraction angles (â¼30° to 65°). The spectrometer is enclosed in a vacuum chamber, and a sample chamber with independent ambient conditions is introduced to enable a versatile and fast-access sample environment (e.g., solid/gas/liquid samples, in situ cells, and radioactive materials). The design, capabilities, and performance are presented and discussed.
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There is sparse direct experimental evidence that atomic nuclei can exhibit stable "pear" shapes arising from strong octupole correlations. In order to investigate the nature of octupole collectivity in radium isotopes, electric octupole (E3) matrix elements have been determined for transitions in ^{222,228}Ra nuclei using the method of sub-barrier, multistep Coulomb excitation. Beams of the radioactive radium isotopes were provided by the HIE-ISOLDE facility at CERN. The observed pattern of E3 matrix elements for different nuclear transitions is explained by describing ^{222}Ra as pear shaped with stable octupole deformation, while ^{228}Ra behaves like an octupole vibrator.
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There is a large body of evidence that atomic nuclei can undergo octupole distortion and assume the shape of a pear. This phenomenon is important for measurements of electric-dipole moments of atoms, which would indicate CP violation and hence probe physics beyond the Standard Model of particle physics. Isotopes of both radon and radium have been identified as candidates for such measurements. Here, we observed the low-lying quantum states in 224Rn and 226Rn by accelerating beams of these radioactive nuclei. We show that radon isotopes undergo octupole vibrations but do not possess static pear-shapes in their ground states. We conclude that radon atoms provide less favourable conditions for the enhancement of a measurable atomic electric-dipole moment.
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After a minor blow to the neck from the handlebars of a bike, a 5-year-old boy developed a massive subcutaneous emphysema with respiratory distress. Orotracheal intubation was performed. A computed tomography (CT) scan of the neck and thorax showed a pneumomediastinum and a bilateral pneumothorax. No injury to the large airways was identified. The patient was stabilized by insertion of chest tubes and controlled ventilation. The endoscopic examination of the trachea revealed a tear of the pars membranacea, which was successfully treated conservatively. The specific features of the injury and the airway management are discussed based on a review of the current literature.
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Traumatismos del Cuello/diagnóstico por imagen , Enfisema Subcutáneo/terapia , Manejo de la Vía Aérea , Preescolar , Endoscopía , Humanos , Intubación Intratraqueal , Masculino , Traumatismos del Cuello/terapiaRESUMEN
BACKGROUND: In most developed countries there is an increasing ageing population living in the community with long-term conditions and sensory impairment (sight; hearing; dual impairment). Community pharmacy personnel are key providers of pharmaceutical care to this patient population. OBJECTIVE: This study explored community pharmacy personnel's experiences with providing pharmaceutical care for older people with sensory impairment. METHODS: Semi-structured telephone interviews were conducted with community pharmacy personnel across Scotland between 2015 and 2016. RESULTS: Thirty interviews were completed with community pharmacists (nâ¯=â¯17) and other pharmacy personnel (nâ¯=â¯13). Two overarching themes emerged: safety and communication. Interviewees reported patients' reluctance to disclose their impairment "patients are very good at hiding it" and had considerable safety concerns "it's a fear that they're going to take too much accidentally taking the same medicine twice". Difficulties in communication were cited "no matter what you do or how you label things, leaflets and telling people, things can go wrong". Additionally, interviewees identified training needs to increase their disability awareness and to identify strategies to provide safe and reliable pharmaceutical care to this vulnerable group "We don't specifically have anything in place to deal with anyone with impairments of that kind". CONCLUSIONS: This is the first in-depth exploration of providing pharmaceutical care to older people with sensory impairment from the perspective of community pharmacy personnel. Strategies are needed to encourage older people to disclose their sensory impairment. Education and training are also needed to optimise the provision of pharmaceutical care to this vulnerable population.
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Envejecimiento , Servicios Comunitarios de Farmacia , Personas con Discapacidad , Servicios de Salud para Ancianos , Seguridad del Paciente , Farmacéuticos , Trastornos de la Sensación/complicaciones , Anciano , Actitud del Personal de Salud , Concienciación , Comunicación , Revelación , Femenino , Humanos , Masculino , Educación del Paciente como Asunto , Farmacias , Investigación Cualitativa , EscociaRESUMEN
The aim of this research was to develop a tool to identify and assess the qualities of cancer-related loneliness in adult cancer survivors who have completed treatment. In addition to reporting the development of the tool, we explicate the process of using the findings of a qualitative analysis to generate questionnaire items, as currently little guidance exists on this topic. The findings of our qualitative research exploring the experience of loneliness in adult cancer survivors who had completed treatment, together with the findings of our concept analysis of loneliness, were used to develop an assessment tool for cancer-related loneliness following treatment completion. Cognitive testing was undertaken to assess fidelity of comprehension and feasibility in administration. The Cancer-Related Loneliness Assessment Tool is a 10-item self-report questionnaire capturing the essential elements of cancer-related loneliness following treatment completion. Experts believed the questionnaire to be face-valid and usable in clinical practice, and preliminary cognitive testing indicated that the items generate the information intended and individuals have little trouble completing the tool. Following further development work, the tool could be employed to identify cancer-related loneliness following treatment completion. It could also aid with the development/adaptation and evaluation of person-centred interventions to address such loneliness.
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Supervivientes de Cáncer/psicología , Soledad , Encuestas y Cuestionarios/normas , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Investigación Cualitativa , Reproducibilidad de los Resultados , Apoyo SocialRESUMEN
Wakefulness and sleep are fundamental characteristics of the brain. We, therefore, hypothesized that transmitter systems contribute to their regulation and will exhibit circadian alterations. We assessed the concentration of various neurotransmitter receptors and transporters including adenosinergic (A1AR, A2AAR, and ENT1), dopaminergic (D1R, D2R, and DAT), and serotonergic (5-HT2AR) target proteins. Adult male Sprague Dawley rats were used and maintained in a 12 h light: 12 h dark cycle (lights on from 07:00 h to 19:00 h). We measured receptor and transporter concentrations in different brain regions, including caudate putamen, basal forebrain, and cortex in 4 hour-intervals over a 24 hour-period using quantitative in vitro autoradiography. Investigated receptors and transporters showed no fluctuations in any of the analyzed regions using one-way ANOVA. Only in the horizontal diagonal band of Broca, the difference of A1AR concentration between light and dark phases (t-test) as well as the cosinor analysis of the 24 hour-course were significant, suggesting that this region underlies receptor fluctuations. Our findings suggest that the availability of the investigated neurotransmitter receptors and transporters does not undergo changes in a 24 hour-period. While there are reports on changes in adenosine and dopamine receptors during sleep deprivation, we found no changes in the investigated adenosine, dopamine, and serotonin receptors during regular and undisturbed day-night cycles.
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Encéfalo/metabolismo , Ritmo Circadiano , Receptores Dopaminérgicos/metabolismo , Receptores Purinérgicos P1/metabolismo , Receptores de Serotonina/metabolismo , Animales , Oscuridad , Masculino , Proteínas de Transporte de Neurotransmisores/metabolismo , Fotoperiodo , Ratas Sprague-Dawley , Factores de TiempoRESUMEN
BACKGROUND: An accurate preoperative assessment of cervical lymph node status is a prerequisite for individually tailored cancer therapies in patients with oral squamous cell carcinoma. The detection of malignant spread and its treatment crucially influence the prognosis. The aim of the present study was to analyze the different staging modalities used among patients with a diagnosis of primary oral squamous cell carcinoma between 2008 and 2015. MATERIAL AND METHODS: An analysis of preoperative staging findings, collected by clinical palpation, ultrasound, and computed tomography (CT), was performed. The results obtained were compared with the results of the final histopathological findings of the neck dissection specimens. A statistical analysis using McNemar's test was performed. RESULTS: The sensitivity of CT for the detection of malignant cervical tumor spread was 74.5%. The ultrasound obtained a sensitivity of 60.8%. Both CT and ultrasound demonstrated significantly enhanced sensitivity compared to the clinical palpation with a sensitivity of 37.1%. No significant difference was observed between CT and ultrasound. A combination of different staging modalities increased the sensitivity significantly compared with ultrasound staging alone. No significant difference in sensitivity was found between the combined use of different staging modalities and CT staging alone. The highest sensitivity, of 80.0%, was obtained by a combination of all three staging modalities: clinical palpation, ultrasound and CT. CONCLUSIONS: The present study indicates that CT has an essential role in the preoperative staging of patients with oral squamous cell carcinoma. Its use not only significantly increases the sensitivity of cervical lymph node metastasis detection but also offers a preoperative assessment of local tumor spread and resection borders. An additional non-invasive cervical lymph node examination increases the sensitivity of the tumor staging process and reduces the risk of occult metastasis.
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Carcinoma de Células Escamosas/patología , Neoplasias de la Boca/patología , Cuidados Preoperatorios , Carcinoma de Células Escamosas/diagnóstico , Carcinoma de Células Escamosas/diagnóstico por imagen , Carcinoma de Células Escamosas/cirugía , Femenino , Humanos , Metástasis Linfática , Masculino , Persona de Mediana Edad , Neoplasias de la Boca/diagnóstico , Neoplasias de la Boca/diagnóstico por imagen , Neoplasias de la Boca/cirugía , Estadificación de Neoplasias/métodos , Cuidados Preoperatorios/métodos , Pronóstico , Estudios Retrospectivos , Sensibilidad y Especificidad , Tomografía Computarizada por Rayos X , UltrasonografíaRESUMEN
The ultra-bright femtosecond X-ray pulses provided by X-ray Free Electron Lasers (XFELs) open capabilities for studying the structure and dynamics of a wide variety of biological and inorganic systems beyond what is possible at synchrotron sources. Although the structure and chemistry at the catalytic sites have been studied intensively in both biological and inorganic systems, a full understanding of the atomic-scale chemistry requires new approaches beyond the steady state X-ray crystallography and X-ray spectroscopy at cryogenic temperatures. Following the dynamic changes in the geometric and electronic structure at ambient conditions, while overcoming X-ray damage to the redox active catalytic center, is key for deriving reaction mechanisms. Such studies become possible by using the intense and ultra-short femtosecond X-ray pulses from an XFEL, where sample is probed before it is damaged. We have developed methodology for simultaneously collecting X-ray diffraction data and X-ray emission spectra, using an energy dispersive spectrometer, at ambient conditions, and used this approach to study the room temperature structure and intermediate states of the photosynthetic water oxidizing metallo-protein, photosystem II. Moreover, we have also used this setup to simultaneously collect the X-ray emission spectra from multiple metals to follow the ultrafast dynamics of light-induced charge transfer between multiple metal sites. A Mn-Ti containing system was studied at an XFEL to demonstrate the efficacy and potential of this method.
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Cristalografía por Rayos X , Electrones , Rayos Láser , Catálisis , Rayos XRESUMEN
BACKGROUND: There has been a dramatic increase in the use of dietary supplements over the last few decades and both omega-3 fatty acids and glucosamine are two of the best-selling dietary supplements in many countries. An understanding of omega-3 fatty acids and glucosamine consumption is of significance to health care providers and for future health promotion activities. METHODS: This research involved analysis of data collected from a nationally-representative sample of Australian women as part of the Australian Longitudinal Study on Women's Health (ALSWH). Participants' use of omega-3 fatty acids (FA), glucosamine, their demographics, health status and health care utilisation were measured. Analysis included logistic regression modelling. RESULTS: Of the 10,638 women in the study, 26.8% reported use of omega-3 FA and 15.9% glucosamine. Women with osteoarthritis (OR=2.529; 95% CI: 2.190, 2.921), other arthritis (OR= 1.618; 95% CI: 1.375, 1.905), and joint pain (OR= 2.699; 95% CI: 2.305, 3.160) were more likely to use glucosamine (all p<0.001). In contrast, those with diabetes (OR= 0.471; 95% CI: 0.343, 0.646) or depression (OR= 0.764; 95% CI: 0.657, 0.887) were less likely to use glucosamine (both p<0.001). Women with osteoarthritis (OR=1.481; 95% CI: 1.297, 1.691) and joint pain (OR= 1.456; 95% CI: 1.306, 1.622) were more likely to use omega-3 FA (all p<0.001). CONCLUSIONS: Substantial prevalence rates for use of glucosamine and omega-3 FA amongst mid-aged women highlights the need for health practitioners and policymakers to be mindful of the possible significant role of such supplement use as part of patient health-seeking behaviours.
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Suplementos Dietéticos/estadística & datos numéricos , Ácidos Grasos Omega-3/uso terapéutico , Glucosamina/uso terapéutico , Salud de la Mujer , Adolescente , Adulto , Anciano , Australia/epidemiología , Femenino , Humanos , Estudios Longitudinales , Persona de Mediana Edad , Prevalencia , Adulto JovenRESUMEN
A patient presents with a keratocystic odontogenic tumour of the left maxillary sinus. In computed tomography scans, extensive pressure-induced osseous atrophy of the sinus walls is detected. Endoscopic cystectomy of the tumour was performed, with subsequent clinical follow-up. A second computed tomography scan revealed almost complete regeneration of the sinus walls. Where spontaneous regeneration of osseous structures is possible, restraint should be exercised when assessing indications for bony reconstruction during initial conservative surgery such as enucleation.
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Regeneración Ósea , Neoplasias del Seno Maxilar/cirugía , Seno Maxilar/diagnóstico por imagen , Quistes Odontogénicos/diagnóstico por imagen , Quistes Odontogénicos/cirugía , Tumores Odontogénicos/cirugía , Humanos , Masculino , Seno Maxilar/crecimiento & desarrollo , Seno Maxilar/cirugía , Neoplasias del Seno Maxilar/diagnóstico por imagen , Tumores Odontogénicos/diagnóstico por imagen , Radiografía , Recuperación de la Función , Resultado del TratamientoRESUMEN
Excited states of the neutron-rich nuclei (97,99)Rb were populated for the first time using the multistep Coulomb excitation of radioactive beams. Comparisons of the results with particle-rotor model calculations provide clear identification for the ground-state rotational band of (97)Rb as being built on the πg(9/2) [431] 3/2(+) Nilsson-model configuration. The ground-state excitation spectra of the Rb isotopes show a marked distinction between single-particle-like structures below N=60 and rotational bands above. The present study defines the limits of the deformed region around Aâ¼100 and indicates that the deformation of (97)Rb is essentially the same as that observed well inside the deformed region. It further highlights the power of the Coulomb-excitation technique for obtaining spectroscopic information far from stability. The (99)Rb case demonstrates the challenges of studies with very short-lived postaccelerated radioactive beams.