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An antiferromagnet emits spin currents when time-reversal symmetry is broken. This is typically achieved by applying an external magnetic field below and above the spin-flop transition or by optical pumping. In this work we apply optical pump-THz emission spectroscopy to study picosecond spin pumping from metallic FeRh as a function of temperature. Intriguingly we find that in the low-temperature antiferromagnetic phase the laser pulse induces a large and coherent spin pumping, while not crossing into the ferromagnetic phase. With temperature and magnetic field dependent measurements combined with atomistic spin dynamics simulations we show that the antiferromagnetic spin-lattice is destabilised by the combined action of optical pumping and picosecond spin-biasing by the conduction electron population, which results in spin accumulation. We propose that the amplitude of the effect is inherent to the nature of FeRh, particularly the Rh atoms and their high spin susceptibility. We believe that the principles shown here could be used to produce more effective spin current emitters. Our results also corroborate the work of others showing that the magnetic phase transition begins on a very fast picosecond timescale, but this timescale is often hidden by measurements which are confounded by the slower domain dynamics.
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BACKGROUND: Although, there is a wealth of information in the medical literature on the usefulness of genomic testing in assessing risk and its application in medical oncology decision making, there are no theoretical reflections in the nursing field. AIM: To understand the implications of molecular biology in nursing practice and highlight the role of Nursing Theory in guiding nurses' reasoning. MATERIALS AND METHODS: Searching literature published between 2000 and 2022 in Medline and Google Scholar. Scientific evidence was analysed by the authors expert in different fields. RESULTS: Based on the findings of the literature, concerns have been raised about the proper care of cancer patients who have a genomic risk profile determination. In particular, the absence of theoretical thinking and conceptual models that consider developments in molecular biology and their impact on nursing, in addition to the prevalence of heuristic thinking and the application of clinical patterns in nursing practice, could induce patient misjudgement with inadequate planning of preventive, curative, rehabilitative and educational nursing interventions. Nurses working in the field of oncology should be aware that the risk profile determined by genomics tests is merely the visible and stated portion of the cancer patient: the tip of iceberg. DISCUSSION: This study demonstrates how genomic testing takes into account a fraction of genes discovered in tumour tissue to establish a risk profile. This subset differs, for example, from the social genome, which can determine the risk of dementia, cancer and cardiovascular disease, but in response to social adversity. Nursing theory, which views the environment as a metaparadigm, must consider a conceptual model that can integrate the findings of genomic testing with recommendations from studies on the social genome of humans to make it easier to build nursing treatments that can better reduce these risks. CONCLUSION: A nursing theoretical discourse on genomics is a paramount requirement for developing effective nursing care.
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Neoplasias , Enfermería Oncológica , Humanos , Genómica , Neoplasias/genética , Oncología Médica , Razonamiento Clínico , Epigénesis GenéticaRESUMEN
Interfaces in heavy metal (HM) - antiferromagnetic insulator (AFI) heterostructures have recently become highly investigated and debated systems in the effort to create spintronic devices that function at terahertz frequencies. Such heterostructures have great technological potential because AFIs can generate sub-picosecond spin currents which the HMs can convert into charge signals. In this work we demonstrate an optically induced picosecond spin transfer at the interface between AFIs and Pt using time-domain THz emission spectroscopy. We select two antiferromagnets in the same family of fluoride cubic perovskites, KCoF3 and KNiF3, whose magnon frequencies at the centre of the Brillouin zone differ by an order of magnitude. By studying their behaviour with temperature, we correlate changes in the spin transfer efficiency across the interface to the opening of a gap in the magnon density of states below the Néel temperature. Our observations are reproduced in a model based on the spin exchange between the localized electrons in the antiferromagnet and the free electrons in Pt. Through this comparative study of selected materials, we are able to shine light on the microscopy of spin transfer at picosecond timescales between antiferromagnets and heavy metals and identify a key figure of merit for its efficiency: the magnon gap. Our results are important for progressing in the fundamental understanding of the highly discussed physics of the HM/AFI interfaces, which is the necessary cornerstone for the designing of femtosecond antiferromagnetic spintronics devices with optimized characteristics.
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Cancer is the second leading cause of noncommunicable disease death, with an increasing incidence. Qigong practice can moderate non-intrinsic, modifiable risk factors that act on the stress response using physical movements, breathing, and focused attention. The purpose of this umbrella review is to provide a concise summary to facilitate an evidence-based decision to integrate Qigong into cancer patients' care. Relevant systematic reviews and meta-analyses were identified and retrieved from the JBI database, Cochrane Library, PubMed, Embase, and CINAHL. Of all of the studies assessed, none found evidence of a risk to cancer patients, indicating that Qigong is a safe practice that can be used even by frail patients. The overall quality of life, cancer-related fatigue, and cognitive impairment were improved by Qigong. Different Qigong programs have different impacts on sleep quality and gastrointestinal problems, suggesting that longer practice sessions are required to achieve improvements. To maintain Qigong's effectiveness, an ordinary practice is essential, or such effectiveness will wear off. The use of biological markers in efficacy assessments needs to be more systematically studied. However, positive WBC, RBC, and CRP trends in Qigong practitioners are evident. Higher-quality clinical studies are necessary to measure variables more closely related to Qigong functioning and consider cancer's multifactorial nature.
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. The management of sexual problems in cancer patients. Sexual dysfunction is one of the most common and distressing consequences of cancer treatment. Many survivors face long-term effects such as treatment-induced menopause, altered gonadal function, and significant surgical disfigurement but some treatment-related sexual adverse effects are short-term. Many survivors do not feel prepared for potential sexual changes and often do not receive adequate support to manage sexual dysfunction. A concise review of the most common sexual problems experienced by cancer ptients is presented together with the main evidence based interventions to suggest to address sexual dysfunction.
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Neoplasias , Disfunciones Sexuales Fisiológicas , Femenino , Humanos , Neoplasias/complicaciones , Neoplasias/terapia , Disfunciones Sexuales Fisiológicas/etiología , Disfunciones Sexuales Fisiológicas/terapia , SobrevivientesRESUMEN
5d metals are used in electronics because of their high spin-orbit coupling (SOC) leading to efficient spin-electric conversion. When C60 is grown on a metal, the electronic structure is altered due to hybridization and charge transfer. In this work, we measure the spin Hall magnetoresistance for Pt/C60 and Ta/C60, finding that they are up to a factor of 6 higher than those for pristine metals, indicating a 20-60% increase in the spin Hall angle. At low fields of 1-30 mT, the presence of C60 increased the anisotropic magnetoresistance by up to 700%. Our measurements are supported by noncollinear density functional theory calculations, which predict a significant SOC enhancement by C60 that penetrates through the Pt layer, concomitant with trends in the magnetic moment of transport electrons acquired via SOC and symmetry breaking. The charge transfer and hybridization between the metal and C60 can be controlled by gating, so our results indicate the possibility of dynamically modifying the SOC of thin metals using molecular layers. This could be exploited in spin-transfer torque memories and pure spin current circuits.
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Twenty-two pharmaceutical formulations containing prednisolone or prednisone commercially available in Italy, Belgium, Spain, Brazil, and India were analyzed through a specific gas chromatography combustion isotope ratio mass spectrometry (GC-C-IRMS) method. All of them showed typical non-endogenous δ13 C values, except for the Belgian nasal spray, Sofrasolone®, with a less depleted 13 C content (-17.84 ± 0.18). Observational studies were performed on two volunteers in therapy with Sofrasolone® to confirm the applicability of the method and to suggest adequate interpretation criteria also in the case of drugs with less negative δ13 C values. Urine samples were collected before, during, and within the 36 hours after the administration of the spray. Both δ13 C values and urinary concentrations of prednisolone and prednisone were evaluated. All samples were subjected to an adequate pre-treatment (enzymatic hydrolysis, liquid/liquid extraction, and two sequential HPLC steps) before injection to the GC-C-IRMS instrument, according to the method recently developed and validated in our laboratory. Pregnanediol (PD), tetrahydro-11-deoxycortisol (THS), and pregnanetriol (PT) were selected as endogenous reference compounds (ERC). The excretion profile was estimated through liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) method used routinely for the quali-quantitative detection of glucocorticoids. δ13 C values and urinary levels of prednisolone and prednisone were also determined after the intake of one single vial of Sintredius®, a prednisolone oral formulation with a conventional more negative δ13 C value (-29.28 ± 0.25). Finally, the potential masking effect that combined therapy with Sofrasolone® and Sintredius® could induce on the IRMS findings was investigated.
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Isótopos de Carbono/orina , Doping en los Deportes/prevención & control , Composición de Medicamentos/métodos , Prednisolona/orina , Prednisona/orina , Detección de Abuso de Sustancias/métodos , Administración Intranasal , Administración Oral , Adulto , Doping en los Deportes/métodos , Composición de Medicamentos/normas , Femenino , Cromatografía de Gases y Espectrometría de Masas/métodos , Cromatografía de Gases y Espectrometría de Masas/normas , Humanos , Masculino , Prednisolona/administración & dosificación , Prednisolona/química , Prednisona/administración & dosificación , Prednisona/química , Detección de Abuso de Sustancias/normas , Adulto JovenRESUMEN
Understanding the transfer of spin angular momentum is essential in modern magnetism research. A model case is the generation of magnons in magnetic insulators by heating an adjacent metal film. Here, we reveal the initial steps of this spin Seebeck effect with <27 fs time resolution using terahertz spectroscopy on bilayers of ferrimagnetic yttrium iron garnet and platinum. Upon exciting the metal with an infrared laser pulse, a spin Seebeck current js arises on the same ~100 fs time scale on which the metal electrons thermalize. This observation highlights that efficient spin transfer critically relies on carrier multiplication and is driven by conduction electrons scattering off the metal-insulator interface. Analytical modeling shows that the electrons' dynamics are almost instantaneously imprinted onto js because their spins have a correlation time of only ~4 fs and deflect the ferrimagnetic moments without inertia. Applications in material characterization, interface probing, spin-noise spectroscopy and terahertz spin pumping emerge.
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Unlike conventional spin-singlet Cooper pairs, spin-triplet pairs can carry spin1,2. Triplet supercurrents were discovered in Josephson junctions with metallic ferromagnet spacers, where spin transport can occur only within the ferromagnet and in conjunction with a charge current. Ferromagnetic resonance injects a pure spin current from a precessing ferromagnet into adjacent non-magnetic materials3,4. For spin-singlet pairing, the ferromagnetic resonance spin pumping efficiency decreases below the critical temperature (Tc) of a coupled superconductor5,6. Here we present ferromagnetic resonance experiments in which spin sink layers with strong spin-orbit coupling are added to the superconductor. Our results show that the induced spin currents, rather than being suppressed, are substantially larger in the superconducting state compared with the normal state; although further work is required to establish the details of the spin transport process, we show that this cannot be mediated by quasiparticles and is most likely a triplet pure spin supercurrent.
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Few resources are available to quantify clinical trial-associated workload, needed to guide staffing and budgetary planning. The aim of the study is to describe a tool to measure clinical trials nurses' workload expressed in time spent to complete core activities. Clinical trials nurses drew up a list of nursing core activities, integrating results from literature searches with personal experience. The final 30 core activities were timed for each research nurse by an outside observer during daily practice in May and June 2014. Average times spent by nurses for each activity were calculated. The "Nursing Time Required by Clinical Trial-Assessment Tool" was created as an electronic sheet that combines the average times per specified activities and mathematic functions to return the total estimated time required by a research nurse for each specific trial. The tool was tested retrospectively on 141 clinical trials. The increasing complexity of clinical research requires structured approaches to determine workforce requirements. This study provides a tool to describe the activities of a clinical trials nurse and to estimate the associated time required to deliver individual trials. The application of the proposed tool in clinical research practice could provide a consistent structure for clinical trials nursing workload estimation internationally.
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Ensayos Clínicos como Asunto , Oncología Médica , Investigación en Enfermería , Carga de Trabajo , HumanosRESUMEN
Recent years have seen great progress in our understanding of the electronic properties of nanomaterials in which at least one dimension measures less than 100 nm. However, contacting true nanometer scale materials such as individual molecules or nanoparticles remains a challenge as even state-of-the-art nanofabrication techniques such as electron-beam lithography have a resolution of a few nm at best. Here we present a fabrication and measurement technique that allows high sensitivity and high bandwidth readout of discrete quantum states of metallic nanoparticles which does not require nm resolution or precision. This is achieved by coupling the nanoparticles to resonant electrical circuits and measurement of the phase of a reflected radio-frequency signal. This requires only a single tunnel contact to the nanoparticles thus simplifying device fabrication and improving yield and reliability. The technique is demonstrated by measurements on 2.7 nm thiol coated gold nanoparticles which are shown to be in excellent quantitative agreement with theory.
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We propose a novel hybrid single-electron device for reprogrammable low-power logic operations, the magnetic single-electron transistor (MSET). The device consists of an aluminium single-electron transistor with a GaMnAs magnetic back-gate. Changing between different logic gate functions is realized by reorienting the magnetic moments of the magnetic layer, which induces a voltage shift on the Coulomb blockade oscillations of the MSET. We show that we can arbitrarily reprogram the function of the device from an n-type SET for in-plane magnetization of the GaMnAs layer to p-type SET for out-of-plane magnetization orientation. Moreover, we demonstrate a set of reprogrammable Boolean gates and its logical complement at the single device level. Finally, we propose two sets of reconfigurable binary gates using combinations of two MSETs in a pull-down network.
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Campos Magnéticos , Modelos Teóricos , Transistores ElectrónicosRESUMEN
The interplay between spin, charge and orbital degrees of freedom has led to the development of spintronic devices such as spin-torque oscillators and spin-transfer torque magnetic random-access memories. In this development, spin pumping represents a convenient way to electrically detect magnetization dynamics. The effect originates from direct conversion of low-energy quantized spin waves in the magnet, known as magnons, into a flow of spins from the precessing magnet to adjacent leads. In this case, a secondary spin-charge conversion element, such as heavy metals with large spin Hall angle or multilayer layouts, is required to convert the spin current into a charge signal. Here, we report the experimental observation of charge pumping in which a precessing ferromagnet pumps a charge current, demonstrating direct conversion of magnons into high-frequency currents via the relativistic spin-orbit interaction. The generated electric current, unlike spin currents generated by spin-pumping, can be directly detected without the need of any additional spin-charge conversion mechanism. The charge-pumping phenomenon is generic and gives a deeper understanding of its reciprocal effect, the spin orbit torque, which is currently attracting interest for their potential in manipulating magnetic information.
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A metallic double dot is measured with radio frequency reflectometry. Changes in the total electron number of the double dot are determined via single electron tunnelling contributions to the complex electrical impedance. Electron counting experiments are performed by monitoring the impedance, demonstrating operation of a single electron ammeter without the need for external charge detection.