thinning

Atom-probe tomography (APT) is a unique analysis tool that enables true three-dimensional (3-D) analyses with sub-nano scale spatial resolution. Recent implementations of the local-electrode atom-probe (LEAP) tomograph with ultraviolet laser pulsing have significantly expanded the research applications of APT. The small field-of-view of a needle-shaped specimen with a less than 100 nm diam. is, however, a major limitation for analyzing materials. The systematic approaches for site-specific targeting of an APT nanotip in a transmission electron microscope (TEM) of a thin sample are introduced to solve the geometrical limitations of a sharpened APT nanotip...

Neuroaxonal pathology is a main determinant of disease progression in multiple sclerosis; however, its underlying pathophysiological mechanisms, including its link to inflammatory demyelination and temporal occurrence in the disease course are still unknown. We used ultra-high field (7 T), ultra-high gradient strength diffusion and T1/T2-weighted myelin-sensitive magnetic resonance imaging to characterize microstructural changes in myelin and neuroaxonal integrity in the cortex and white matter in early stage multiple sclerosis, their distribution in lesional and normal-appearing tissue, and their correlations with neurological disability...

In vivo microinjection is the most commonly used gene transfer technique for analyzing the gene functions in individual mosquitoes. However, this method requires a more technically demanding operation and involves complicated procedures, especially when used in larvae due to their small size, relatively thin and fragile cuticle, and high mortality, which limit its application. In contrast, viral vectors for gene delivery have been developed to surmount extracellular and intracellular barriers. These systems have the advantages of easy manipulation, high gene transduction efficiency, long-term maintenance of gene expression, and the ability to produce persistent effects in vivo...

PURPOSE: To report a case of peripheral ulcerative keratitis secondary to gout. METHODS: A 41-year-old man with a history of severe gout disease presented with pain and redness of the right eye. Physical examination revealed 2 areas of peripheral corneal thinning with overlying epithelial defects. Adjacent to these areas, reflective crystals were identified in the corneal stroma. Anterior segment optical coherence tomography demonstrated stromal corneal deposits...

PURPOSE: To evaluate the surface characteristics of lenticules created by small-incision lenticule extraction (SMILE) with different cap thicknesses. METHODS: This prospective study included 20 consecutive patients who underwent bilateral SMILE. Surface regularity of the extracted corneal lenticule was analyzed using scanning electron microscopy (SEM) combined with 2 methods: qualitative and quantitative regularity. Qualitative regularity of SEM images was graded by masked observers using an established scoring system...

In the present work we predict, through first-principles calculations, that bilayers of the recently synthesized Ni3 [Formula: see text] [Formula: see text] and Pt3 [Formula: see text] [Formula: see text] layered materials are topological insulators upon electron doping, and that their topological insulator properties can be modulated by the application of electric fields with magnitudes achievable in devices. The electronic structures of both bilayers are characterized by spin-orbit split graphene-like bands, with gap magnitudes that are three orders of magnitude larger than graphene's...

By dual gating a few-layer MoS_{2} flake, we induce spatially separated electronic states showing superconductivity and Shubnikov-de Haas (SdH) oscillations. While the highly confined superconductivity forms at the K/K^{'} valleys of the topmost layer, the SdH oscillations are contributed by the electrons residing in the Q/Q^{'} valleys of the rest of the bottom layers, which is confirmed by the extracted Landau level degeneracy of 3, electron effective mass of 0.6m_{e}, and carrier density of 5×10^{12}  cm^{-2}...

The ability to monitor biomolecular reactions in a real-time and label free manner is nearly synonymous with the surface plasmon resonance (SPR) technique. At its basis, SPR relies on the interaction of an incoming light source with a thin metallic film in close contact with a prism or grating, which, under the correct experimental conditions, allows for the propagative oscillation of the conduction electrons at the surface of the metallic material. The oscillating, electromagnetic fields are extremely sensitive to small changes in the refractive index within the dielectric near the sensing interface, where various binding events and interactions can be detected...

The challenges of global climate change and the world's growing demand for energy have brought the need for new renewable energy sources to the top of the international community's agenda. We have known for many centuries that energy is released upon mixing seawater and freshwater, yet it was just a few decades ago that it became clear how this energy can be converted into electricity instead of heat. As a result, the blue energy rush has raised and set new strategies in different science and technology sectors, leading to the construction of a new generation of plants and other technological investments...

Background Few data are available on risk factors and associations with outcomes in symptomatic peripheral artery disease (PAD) populations in primary care. We assessed characteristics and cardiovascular outcomes in patients with and those without symptomatic peripheral artery disease in UK primary care, and quantified risk factors for cardiovascular outcomes in patients with peripheral artery disease. Methods Among patients in The Health Improvement Network (THIN) aged 50-89 years in 2000-2010, a symptomatic peripheral artery disease cohort ( n = 28,484) and a matched comparison cohort without peripheral artery disease ( n = 113,940) were identified using Read codes...

Facile fabrication of advanced catalysts toward oxygen reduction reaction with improving activity and stability is significant for proton-exchange membrane fuel cells. Based on a generic solid-state reaction, this study reports a modified hydrogen-assisted, gas-phase synthesis for facile, scalable production of surfactant-free, thin, platinum-based nanowire-network electrocatalysts. The free-standing platinum and platinum-nickel alloy nanowires show improvements of up to 5.1 times and 10.9 times for mass activity with a minimum 2...

The thin-film directed self-assembly of molecular building blocks into oriented nanostructure arrays enables next-generation lithography at the sub-5 nm scale. Currently, the fabrication of inorganic arrays from molecular building blocks is restricted by the limited long-range order and orientation of the materials, as well as suitable methodologies for creating lithographic templates at sub-5 nm dimensions. In recent years, higher-order liquid crystals have emerged as functional thin films for organic electronics, nanoporous membranes, and templated synthesis, which provide opportunities for their use as lithographic templates...

It has been difficult to produce acceptable pecan butters as the high oil content results in a product that flows and separates too easily. The objective of this work was to create pecan butters with varying oil levels (50-70%) and determine which would give the most acceptable product. Consumers rated pecan butters with 55-60% oil the most acceptable, whether roasted or not. Acceptability varied most in terms of texture and spreadability, but not flavor. Under large deformation firmness varied from 51.8 g (70% oil) to 4880 g (50%) oil, while 'spreadability' ranged from 19...

Swallowing impairment (dysphagia) is a common sequela in patients with motor neuron disease (MND). The purpose of this retrospective, observational pilot investigation was to characterize how pharyngeal swallowing mechanics are impacted in patients with MND using a comparison with healthy, non-dysphagic control group. Computational analysis of swallowing mechanics (CASM) was used to determine covariate biomechanics of pharyngeal swallowing from videofluoroscopic assessment in 15 patients with MND and 15 age- and sex-matched healthy controls...

Histological analysis has been largely confined to two-dimensional analysis of thin tissue sections, hampering detailed understanding of three-dimensional cellular distribution in biological tissues. Tissue optical clearing methods enable three-dimensional histological analysis by rendering tissues transparent and suitable for microscopic detection of the fluorescent signals inside. Despite their great potential in histological research, the tissue clearing methods are not readily accessible to many researchers because of hazardous chemicals, complicated protocols and advanced microscopy...

Nanomechanical measurements of platinum-carbon 3D nanoscale architectures grown via focused electron beam induced deposition (FEBID) were performed using a nanoindentation system in a scanning electron microscope (SEM) for simultaneous in situ imaging. Compression tests were used to estimate the modulus of the platinum-carbon deposits to be in the range of 8.6-10.5 GPa. Cantilever arm bend tests resulted in a modulus estimation of 15.6 GPa. Atomic layer deposition was used to conformally coat FEBID structures with a thin film of Al2O3, which strengthened the structures and increased the measured modulus...

ReS2 films is considered as a promising candidate for optoelectronic applications due to its direct bandgap character and optical/electrical anisotropy. However, the direct bandgap in a narrow spectrum and the low absorption of atomically thin flake weaken the prospect for light-harvesting applications. Here, we developed an efficient approach to enhance the performance of ReS2-based phototransistor by coupling CdSe-CdS-ZnS core-shell quantum dots. Under 589 nm laser irradiation, the responsivity of ReS2 phototransistor decorated with quantum dots could be enhanced by more than 25 times (up to ~654 A/W), and the rising and recovery time can be also reduced to 3...

Optical emission behaviours of lysozyme and bovine serum albumin, from bulk and thin film geometry, were studied in the presence of three different divalent ions (Mg(2+) , Ca(2+) or Ba(2+) ) using different spectroscopic [steady-state fluorescence, UV-Vis and Fourier transform infra-red (FTIR)] techniques. Additionally, protein thin films on silicon surfaces were prepared and morphological studies were carried out using atomic force microscopy. Dynamic quenching was mainly identified for both proteins in the presence of Mg(2+) , Ca(2+) and Ba(2+) ions...

Contraction of heart muscle is triggered by a transient rise in intracellular free calcium concentration linked to a change in the structure of the actin-containing thin filaments that allows the head or motor domains of myosin from the thick filaments to bind to them and induce filament sliding. It is becoming increasingly clear that cardiac contractility is also regulated through structural changes in the thick filaments, although the molecular mechanisms underlying thick filament regulation are still relatively poorly understood...

Gas-liquid interfaces broadly impact our planet, yet confined interfaces behave differently than unconfined ones. We report the role of tangential fluid motion in confined methane-water interfaces. The interfaces are created using microfluidics and investigated by in situ 1D, 2D and 3D Raman spectroscopy. The apparent CH4 and H2O concentrations are reported for Reynolds numbers (Re), ranging from 0.17 to 8.55. Remarkably, the interfaces are comprised of distinct layers of thicknesses varying from 23 to 57 μm...