Nanofountain‐Probe‐Based High‐Resolution Patterning and Single‐Cell Injection of Functionalized Nanodiamonds

Nanodiamonds are rapidly emerging as promising carriers for next‐generation therapeutics and drug delivery. However, developing future nanoscale devices and arrays that harness these nanoparticles will require unrealized spatial control. Furthermore, single‐cell in vitro transfection methods lack an instrument that simultaneously offers the advantages of having nanoscale dimensions and control and continuous delivery via microfluidic components. To address this, two modes of controlled delivery of functionalized diamond nanoparticles are demonstrated using a broadly applicable nanofountain probe, a tool for direct‐write nanopatterning with sub‐100‐nm resolution and direct in vitro single‐cell injection. This study demonstrates the versatility of the nanofountain probe as a tool for high‐fidelity delivery of functionalized nanodiamonds and other agents in nanomanufacturing and single‐cell biological studies. These initial demonstrations of controlled delivery open the door to future studies examining the nanofountain probe's potential in delivering specific doses of DNA, viruses, and other therapeutically relevant biomolecules.     

Merger of structure and material in nacre and bone – Perspectives on de novo biomimetic materials

In contrast to synthetic materials, evolutionary developments in biology have resulted in materials with remarkable structural properties, made out of relatively weak constituents, arranged in complex hierarchical patterns. For instance, nacre from seashells is primarily made of a fragile ceramic, yet it exhibits superior levels of strength and toughness. Structural features leading to this performance consist of a microstructure organized in a hierarchical fashion, and the addition of a small volume fraction of biopolymers. A key to this mechanical performance is the cohesion and sliding of wavy ceramic tablets. Another example is bone, a structural biological material made of a collagen protein phase and nanoscopic mineral platelets, reaching high levels of toughness and strength per weight. The design and fabrication of de novo synthetic materials that aim to utilize the deformation and hardening mechanism of biological materials such as bone or nacre is an active area of research in mechanics of materials. In this review, our current knowledge on microstructure and mechanics of nacre and bone are described, and a review of the fabrication of nacre-inspired artificial and related materials is presented. Both experimental and simulation approaches are discussed, along with specific examples that illustrate the various approaches. We conclude with a broader discussion of the interplay of size effects and hierarchies in defining mechanical properties of biological materials.     

Lattice dynamics of Ga1?xMnxN and Ga1?xMnxAs by first-principle calculations

In this work, we present theoretical results, using first-principle methods associated to the virtual crystal approximation model, for the vibrational mode frequencies of both the Ga_1−xMn_xN (in both cubic and hexagonal structures) and the Ga_1−xMn_xAs alloys, with the Mn contents in the range of 0% to 20%. The dependence of the calculated phonon frequencies with the Mn content was analyzed, and the results indicate that the phonon frequencies decrease with the increasing of Mn composition, leading to the false impression that they obey the Vegard rule in some cases. Moreover, the hexagonal Ga_1−xMn_xN alloys are elastically unstable for Mn concentrations at the order of 20%, which explains in part the experimentally observed deterioration of these alloys. These findings can be used in future technologies as a guide for the synthesis of spintronic nanostructured devices, such as nanowires, based on these materials.     

Study of the oxygen vacancy influence on magnetic properties of Fe- and Co-doped SnO2 diluted alloys

Transition-metal (TM)-doped diluted magnetic oxides (DMOs) have attracted attention from both experimental and theoretical points of view due to their potential use in spintronics towards new nanostructured devices and new technologies. In the present work, we study the magnetic properties of Sn_0.96TM_0.04O₂ and Sn_0.96TM_0.04O_1.98(V_O)_0.02, where TM = Fe and Co, focusing in particular in the role played by the presence of O vacancies nearby the TM. The calculated total energy as a function of the total magnetic moment per cell shows a magnetic metastability, corresponding to a ground state, respectively, with 2 and 1 μ_B/cell, for Fe and Co. Two metastable states, with 0 and 4 μ_B/cell were found for Fe, and a single value, 3 μ_B/cell, for Co. The spin-crossover energies (E_S) were calculated. The values are E_S^0/2 = 107 meV and E_S^4/2 = 25 meV for Fe. For Co, E_S^3/1 = 36 meV. By creating O vacancies close to the TM site, we show that the metastablity and E_S change. For iron, a new state appears, and the state with zero magnetic moment disappears. The ground state is 4 μ_B/cell instead of 2 μ_B/cell, and the energy E_S^2/4 is 30 meV. For cobalt, the ground state is then found with 3 μ_B/cell and the metastable state with 1 μ_B/cell. The spin-crossover energy E_S^1/3 is 21 meV. Our results suggest that these materials may be used in devices for spintronic applications that require different magnetization states.     

Autonomic Coordination of Skeleton-Based Applications Over CPU/GPU Multi-Core Architectures

Widely adumbrated as patterns of parallel computation and communication, algorithmic skeletons introduce a viable solution for efficiently programming modern heterogeneous multi-core architectures equipped not only with traditional multi-core CPUs, but also with one or more programmable Graphics Processing Units (GPUs). By systematically applying algorithmic skeletons to address complex programming tasks, it is arguably possible to separate the coordination from the computation in a parallel program, and therefore subdivide a complex program into building blocks (modules, skids, or components) that can be independently created and then used in different systems to drive multiple functionalities. By exploiting such systematic division, it is feasible to automate coordination by addressing extra-functional and non-functional features such as application performance, portability, and resource utilisation from the component level in heterogeneous multi-core architectures. In this paper, we introduce a novel approach to exploit the inherent features of skeleton-based applications in order to automatically coordinate them over heterogeneous (CPU/GPU) multi-core architectures and improve their performance. Our systematic evaluation demonstrates up to one order of magnitude speed-up on heterogeneous multi-core architectures.     

Effects of network communications on a class of learning controlled non-linear systems†

In this article, an iterative learning control approach is proposed for a class of sampled-data non-linear systems over network communication channels. The effects of constant time delays and stochastic packet loss are discussed and demonstrated by simulation results. The focus of this article is to study the remote control problems when the environment is periodic or repeatable over iterations in a fixed finite interval. Because of the existence of time delays and packet loss in input and output signal transmissions, it is not trivial to accomplish the remote stabilisation task of any system. Moreover, to track a desired trajectory through a remote controller is even more difficult. Previous cycle-based learning method is incorporated into the network-based control for a class of non-linear systems which satisfies a global Lipschitz condition. The convergence property of this approach is proven. Furthermore, the convergence in the iteration domain is also discussed when there exists packet loss in both transmission channels of the system. Finally, one single-link rigid robot is given as an example to show the effectiveness of the proposed approach.     

A multiplexed immunoassay system based upon reciprocating centrifugal microfluidics

A novel, centrifugal disk-based micro-total analysis system (μTAS) for low cost and high throughput semi-automated immunoassay processing was developed. A key innovation in the disposable immunoassay disk design is in a fluidic structure that enables very efficient micro-mixing based on a reciprocating mechanism in which centrifugal acceleration acting upon a liquid element first generates and stores pneumatic energy that is then released by a reduction of the centrifugal acceleration, resulting in a reversal of direction of flow of the liquid. Through an alternating sequence of high and low centrifugal acceleration, the system reciprocates the flow of liquid within the disk to maximize incubation/hybridization efficiency between antibodies and antigen macromolecules during the incubation/hybridization stage of the assay. The described reciprocating mechanism results in a reduction in processing time and reagent consumption by one order of magnitude.     

Reduction in personal exposures to particulate matter and carbon monoxide as a result of the installation of a Patsari improved cook stove in Michoacan Mexico

The impact of an improved wood burning stove (Patsari) in reducing personal exposures and indoor concentrations of particulate matter (PM(2.5)) and carbon monoxide (CO) was evaluated in 60 homes in a rural community of Michoacan, Mexico. Average PM(2.5) 24-h personal exposure was 0.29 mg/m(3) and mean 48-h kitchen concentration was 1.269 mg/m(3) for participating women using the traditional open fire (fogon). If these concentrations are typical of rural conditions in Mexico, a large fraction of the population is chronically exposed to levels of pollution far higher than ambient concentrations found by the Mexican government to be harmful to human health. Installation of an improved Patsari stove in these homes resulted in 74% reduction in median 48-h PM(2.5) concentrations in kitchens and 35% reduction in median 24-h PM(2.5) personal exposures. Corresponding reductions in CO were 77% and 78% for median 48-h kitchen concentrations and median 24-h personal exposures, respectively. The relationship between reductions in median kitchen concentrations and reductions in median personal exposures not only changed for different pollutants, but also differed between traditional and improved stove type, and by stove adoption category. If these reductions are typical, significant bias in the relationship between reductions in particle concentrations and reductions in health impacts may result, if reductions in kitchen concentrations are used as a proxy for personal exposure reductions when evaluating stove interventions. In addition, personal exposure reductions for CO may not reflect similar reductions for PM(2.5). This implies that PM(2.5) personal exposure measurements should be collected or indoor measurements should be combined with better time-activity estimates, which would more accurately reflect the contributions of indoor concentrations to personal exposures. PRACTICAL IMPLICATIONS: Installation of improved cookstoves may result in significant reductions in indoor concentrations of carbon monoxide and fine particulate matter (PM(2.5)), with concurrent but lower reductions in personal exposures. Significant errors may result if reductions in kitchen concentrations are used as a proxy for personal exposure reductions when evaluating stove interventions in epidemiological investigations. Similarly, time microenvironment activity models in these rural homes do not provide robust estimates of individual exposures due to the large spatial heterogeneity in pollutant concentrations and the lack of resolution of time activity diaries to capture movement through these microenvironments.     

Osthol Ameliorates Kidney Damage and Metabolic Syndrome Induced by a High-Fat/High-Sugar Diet

Excessive intake of fructose results in metabolic syndrome (MS) and kidney damage, partly mediated by its metabolism by fructokinase-C or ketohexokinase-C (KHK-C). Osthol has antioxidant properties, is capable of regulating adipogenesis, and inhibits KHK-C activity. Here, we examined the potential protective role of osthol in the development of kidney disease induced by a Western (high-fat/high-sugar) diet. Control rats fed with a high-fat/high-sugar diet were compared with two groups that also received two different doses of osthol (30 mg/kg/d or 40 mg/kg/d body weight BW). A fourth group served as a normal control and received regular chow. At the end of the follow-up, kidney function, metabolic markers, oxidative stress, and lipogenic enzymes were evaluated. The Western diet induced MS (hypertension, hyperglycemia, hypertriglyceridemia, obesity, hyperuricemia), a fall in the glomerular filtration rate, renal tubular damage, and increased oxidative stress in the kidney cortex, with increased expression of lipogenic enzymes and increased kidney KHK expression. Osthol treatment prevented the development of MS and ameliorated kidney damage by inhibiting KHK activity, preventing oxidative stress via nuclear factor erythroid 2-related factor (Nrf2) activation, and reducing renal lipotoxicity. These data suggest that the nutraceutical osthol might be an ancillary therapy to slow the progression of MS and kidney damage induced by a Western diet.