The pain matrix is conceptualised here as a fluid system composed of several interacting networks. A nociceptive matrix receiving spinothalamic projections (mainly posterior operculoinsular areas) ...ensures the bodily specificity of pain and is the only one whose destruction entails selective pain deficits. Transition from cortical nociception to conscious pain relies on a second-order network, including posterior parietal, prefrontal and anterior insular areas. Second-order regions are not nociceptive-specific; focal stimulation does not evoke pain, and focal destruction does not produce analgesia, but their joint activation is necessary for conscious perception, attentional modulation and control of vegetative reactions. The ensuing pain experience can still be modified as a function of beliefs, emotions and expectations through activity of third-order areas, including the orbitofrontal and perigenual/limbic networks. The pain we remember results from continuous interaction of these subsystems, and substantial changes in the pain experience can be achieved by acting on each of them. Neuropathic pain (NP) is associated with changes in each of these levels of integration. The most robust abnormality in NP is a functional depression of thalamic activity, reversible with therapeutic manoeuvres and associated with rhythmic neural bursting. Neuropathic allodynia has been associated with enhancement of ipsilateral over contralateral insular activation and lack of reactivity in orbitofrontal/perigenual areas. Although lack of response of perigenual cortices may be an epiphenomenon of chronic pain, the enhancement of ipsilateral activity may reflect disinhibition of ipsilateral spinothalamic pathways due to depression of their contralateral counterpart. This in turn may bias perceptual networks and contribute to the subjective painful experience.
•An algorithm coded in C environment is developed to enhance the performance of the IREC’s microgrid system.•Local energy market cost model is proposed to obtain the best buying price in a day-ahead ...energy market.•Several real technical and market scenarios incorporating demand response, price sorting, etc., are considered in the study.•Simulation results demonstrate a significant reduction in the overall plant cost of the system.
Both performance optimization and scheduling of the distributed generation (DG) are relevant implementing an energy management system (EMS) within Microgrid (MG). Furthermore, optimization methods need to be applied to achieve maximum efficiency, improve economic dispatch as well as acquiring the best performance. This paper proposes an optimization method based on gravitational search algorithm to solve such problem in a MG including different types of DG units with particular attention to the technical constraints. This algorithm includes the implementation of some variation in load consumption model considering accessibility to the energy storage (ES) and demand response (DR). The proposed method is validated experimentally. Obtained results show the improved performance of the proposed algorithm in the isolated MG, in comparison with conventional EMS. Moreover, this algorithm which is feasible from computational viewpoint, has many advantages as peak consumption reduction, electricity generation cost minimization among other.
Perovskite nanocrystals (NCs) have revolutionized optoelectronic devices because of their versatile optical properties. However, controlling and extending these functionalities often requires a ...light‐management strategy involving additional processing steps. Herein, we introduce a simple approach to shape perovskite nanocrystals (NC) into photonic architectures that provide light management by directly shaping the active material. Pre‐patterned polydimethylsiloxane (PDMS) templates are used for the template‐induced self‐assembly of 10 nm CsPbBr3 perovskite NC colloids into large area (1 cm2) 2D photonic crystals with tunable lattice spacing, ranging from 400 nm up to several microns. The photonic crystal arrangement facilitates efficient light coupling to the nanocrystal layer, thereby increasing the electric field intensity within the perovskite film. As a result, CsPbBr3 2D photonic crystals show amplified spontaneous emission (ASE) under lower optical excitation fluences in the near‐IR, in contrast to equivalent flat NC films prepared using the same colloidal ink. This improvement is attributed to the enhanced multi‐photon absorption caused by light trapping in the photonic crystal.
Perovskite nanocrystals (NCs) are self‐assembled into 2D photonic supercrystals using pre‐patterned polydimethylsiloxane (PDMS) templates and their optical spectra are tunable by varying the lattice spacing. These photonic crystals show amplified spontaneous emission (ASE) under lower optical excitation fluences in the near‐IR region due to enhanced multi‐photon absorption caused by light trapping in the photonic crystal.
In this paper, a novel wireless load-sharing controller for islanding parallel inverters in an ac-distributed system is proposed. This paper explores the resistive output impedance of the ...parallel-connected inverters in an island microgrid. The control loops are devised and analyzed, taking into account the special nature of a low-voltage microgrid, in which the line impedance is mainly resistive and the distance between the inverters makes the control intercommunication between them difficult. In contrast with the conventional droop-control method, the proposed controller uses resistive output impedance, and as a result, a different control law is obtained. The controller is implemented by using a digital signal processor board, which only uses local measurements of the unit, thus increasing the modularity, reliability, and flexibility of the distributed system. Experimental results are provided from two 6-kVA inverters connected in parallel, showing the features of the proposed wireless control
Bacterial microcompartments (BMC) are complex macromolecular assemblies that participate in varied chemical processes in about one fourth of bacterial species. BMC-encapsulated enzymatic activities ...are segregated from other cell contents by means of semipermeable shells, justifying why BMC are viewed as prototype nano-reactors for biotechnological applications. Herein, we undertook a comparative study of bending propensities of BMC hexamers (BMC-H), the most abundant shell constituents. Published data show that some BMC-H, like β-carboxysomal CcmK, tend to assemble flat whereas other BMC-H often build curved objects. Inspection of available crystal structures presenting BMC-H in tiled arrangements permitted us to identify two major assembly modes with a striking connection with experimental trends. All-atom molecular dynamics (MD) supported that BMC-H bending is triggered robustly only from the arrangement adopted in crystals by BMC-H that experimentally form curved objects, leading to very similar arrangements to those found in structures of recomposed BMC shells. Simulations on triplets of planar-behaving hexamers, which were previously reconfigured to comply with such organization, confirmed that bending propensity is mostly defined by the precise lateral positioning of hexamers, rather than by BMC-H identity. Finally, an interfacial lysine was pinpointed as the most decisive residue in controlling PduA spontaneous curvature. Globally, results presented herein should contribute to improve our understanding of the variable mechanisms of biogenesis characterized for BMC, and of possible strategies to regulate BMC size and shape.
Biomedical Applications of Metal 3D Printing Velásquez-García, Luis Fernando; Kornbluth, Yosef
Annual review of biomedical engineering,
07/2021, Volume:
23, Issue:
1
Journal Article
Peer reviewed
Open access
Additive manufacturing's attributes include print customization, low per-unit cost for small- to mid-batch production, seamless interfacing with mainstream medical 3D imaging techniques, and ...feasibility to create free-form objects in materials that are biocompatible and biodegradable. Consequently, additive manufacturing is apposite for a wide range of biomedical applications including custom biocompatible implants that mimic the mechanical response of bone, biodegradable scaffolds with engineered degradation rate, medical surgical tools, and biomedical instrumentation. This review surveys the materials, 3D printing methods and technologies, and biomedical applications of metal 3D printing, providing a historical perspective while focusing on the state of the art. It then identifies a number of exciting directions of future growth: (
a
) the improvement of mainstream additive manufacturing methods and associated feedstock; (
b
) the exploration of mature, less utilized metal 3D printing techniques; (
c
) the optimization of additively manufactured load-bearing structures via artificial intelligence; and (
d
) the creation of monolithic, multimaterial, finely featured, multifunctional implants.
Purpose
In velocity‐selective (VS) arterial spin labeling, strategies using multiple saturation modules or using VS inversion (VSI) pulse can provide improved SNR efficiency compared to the original ...labeling scheme using one VS saturation (VSS) module. Their performance improvement, however, has not been directly compared.
Methods
Different VS labeling schemes were evaluated by Bloch simulation for their SNR efficiency, eddy current sensitivity, and robustness against B1 and B0 variation. These schemes included dual‐module double‐refocused hyperbolic secant and symmetric 8‐segment B1‐insensitive rotation (sBIR8‐) VSS pulses, the original and modified Fourier transform‐based VSI pulses. A subset of the labeling schemes was examined further in phantom and in vivo experiments for their eddy current sensitivity and SNR performance. An additional sBIR8‐VSS with a built‐in inversion (sBIR8‐VSS‐inversion) was evaluated for the effects of partial background suppression to allow a fairer comparison to VSI.
Results
According to the simulations, the sBIR8‐VSS was the most robust against field imperfections and had similarly high SNR efficiency (dual‐module, dual‐sBIR8‐VSS) compared with the best VSI pulse (sinc‐modulated, sinc‐VSI). These were confirmed by the phantom and in vivo data. Without additional background suppression, the sinc‐VSI pulses had the highest temporal SNR, closely followed by the sBIR8‐VSS‐inversion pulse, both benefited from partial background suppression effects.
Conclusion
Dual‐sBIR8‐VSS and sinc‐VSI measured the highest SNR efficiency among the VS labeling schemes. Dual‐sBIR8‐VSS was the most robust against field imperfections, whereas sinc‐VSI may provide a higher SNR efficiency if its immunity to field imperfections can be improved.
Standardizing the standards Loss, Lindsey; Tinoco Garcia, Luis; Schreiber, Martin
The American journal of surgery,
20/May , Volume:
231
Journal Article
Peer reviewed
The maintenance of a database for trauma patients is mandated for trauma center accreditation however there is no further standardization beyond that.2 The importance of restarting this database has ...been emphasized by Canadian trauma surgeons. The relatively random nature of these 5 universal complications emphasizes the need for greater standardization of pertinent quality improvement measures. Currently, the National Trauma Databank (NTDB) and Trauma Quality Improvement Program (TQIP) include Canadian Centers but they were not included in this review.3 These databases have allowed the US to create benchmarks for programs to strive for and make targeted plans for quality improvement.3 In the United States, the American College of Surgeons is responsible for trauma center verification and this verification mechanism is used less commonly north of the border.3 In Canada, Accreditation Canada designates Canadian Trauma Centers using set trauma system and trauma center standards developed by the Trauma Association of Canada.4 The core indicators used include field triage, wait time for rehabilitation, trauma team activation, emergency department/acute care length of stay, complications, and mortality.4 The billing for Canadian Healthcare and the US Healthcare systems is very different as Canada has a publicly funded system, thus data on exact trauma costs are more challenging to determine.5 However research into this has shown that major trauma in Canada is also associated with high costs.5 This could be a motivating factor to reinvigorate the Canadian trauma registry and rationale to provide additional funding for this registry with the long term goal of reducing cost via quality improvement and benchmarking.
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