RESUMEN
Two-dimensional (2D) anatase titanium dioxide (TiO2) is expected to exhibit different properties as compared to anatase nanocrystallites, due to its highly reactive exposed facets. However, access to 2D anatase TiO2 is limited by the non-layered nature of the bulk crystal, which does not allow use of top-down chemical exfoliation. Large efforts have been dedicated to the growth of 2D anatase TiO2 with high reactive facets by bottom-up approaches, which relies on the use of harmful chemical reagents. Here, we demonstrate a novel fluorine-free strategy based on topochemical conversion of 2D 1T-TiS2 for the production of single crystalline 2D anatase TiO2, exposing the {001} facet on the top and bottom and {100} at the sides of the nanosheet. The exposure of these faces, with no additional defects or doping, gives rise to a significant activity enhancement in the hydrogen evolution reaction, as compared to commercially available Degussa P25 TiO2 nanoparticles. Because of the strong potential of TiO2 in many energy-based applications, our topochemical approach offers a low cost, green and mass scalable route for production of highly crystalline anatase TiO2 with well controlled and highly reactive exposed facets.
RESUMEN
A well-defined insulating layer is of primary importance in the fabrication of passive ( e.g., capacitors) and active ( e.g., transistors) components in integrated circuits. One of the most widely known two-dimensional (2D) dielectric materials is hexagonal boron nitride (hBN). Solution-based techniques are cost-effective and allow simple methods to be used for device fabrication. In particular, inkjet printing is a low-cost, noncontact approach, which also allows for device design flexibility, produces no material wastage, and offers compatibility with almost any surface of interest, including flexible substrates. In this work, we use water-based and biocompatible graphene and hBN inks to fabricate all-2D material and inkjet-printed capacitors. We demonstrate an areal capacitance of 2.0 ± 0.3 nF cm-2 for a dielectric thickness of â¼3 µm and negligible leakage currents, averaged across more than 100 devices. This gives rise to a derived dielectric constant of 6.1 ± 1.7. The inkjet printed hBN dielectric has a breakdown field of 1.9 ± 0.3 MV cm-1. Fully printed capacitors with sub-micrometer hBN layer thicknesses have also been demonstrated. The capacitors are then exploited in two fully printed demonstrators: a resistor-capacitor (RC) low-pass filter and a graphene-based field effect transistor.
RESUMEN
We propose and demonstrate a novel physical computing paradigm based on an engineered unipolar memristor that exhibits symmetric SET switching with respect to voltage polarity. A one-dimensional array of these devices was sufficient to demonstrate an efficient Hamming distance comparator for two strings of analog states represented by voltages from the physical world. The comparator first simultaneously applies the two sets of voltages to the array of memristors, each of which is initially in its high resistance state and switches to its low resistance state only if the two voltages applied on that memristor differ by more than the switching threshold. An accurate analog representation of the Hamming distance is then obtained by applying a reading voltage to the memristors and summing all the resultant currents. The comparator with a small footprint can directly process analog signals and store computation results without power, representing a promising application for analog computing based on memristor crossbar arrays.
RESUMEN
'Thousands of patients are annually starved in the midst of plenty for want of attention to the ways which alone make it possible for them to take food' (Florence Nightingale, 1860).
Asunto(s)
Servicios de Alimentación/organización & administración , Desnutrición/prevención & control , Terapia Nutricional/normas , Directrices para la Planificación en Salud , Humanos , Desnutrición/epidemiología , Rol de la Enfermera , Política Nutricional , Terapia Nutricional/enfermería , Medicina Estatal/organización & administración , Reino Unido/epidemiologíaRESUMEN
A study by Gosney (2003) aimed to identify the number of prescriptions and consumption of nutritional supplements (sip feeds) over a 24-hour period on an elderly care ward. This included the measurement and collection of anthropometric and biochemical data of patients who did and did not receive sip feeds in order to compare the indication for their use and calculate the cost of wasted feed.
Asunto(s)
Suplementos Dietéticos/estadística & datos numéricos , Geriatría/métodos , Anciano , Índice de Masa Corporal , Costos y Análisis de Costo , Suplementos Dietéticos/economía , Suplementos Dietéticos/normas , Humanos , Albúmina Sérica/análisisRESUMEN
Malnutrition is prevalent in patients with cancer. This can have deleterious effects including reduced response to treatment, diminished quality of life, increased length of hospital stay and decreased survival. It is, therefore, imperative that thorough nutritional screening is carried out by nurses on patients' admission and during their hospital stay to detect those who are malnourished or at risk of malnutrition in order to plan their nutritional care effectively. Cancer cachexia is the progressive weight loss and emaciation seen in cancer patients, particularly in advanced disease, which can have a devastating effect on the physical, psychological, social and spiritual aspects of the patient's life. Therefore, the aims of nutritional care are identified depending on the stage of the patient's illness and recommendations made for nursing, pharmacological and nutritional intervention. These include nursing comfort strategies, the use of recommended pharmacological agents and dietary interventions such as experimenting with different foods, textures, portion sizes and nutritional supplements. The use of fish oil-enhanced nutritional supplements and artificial nutritional support is also discussed. Consideration is also given to the legal and ethical aspects of providing nutrition and nutritional support.