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1.
Nano Lett ; 24(35): 10834-10841, 2024 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-39093057

RESUMO

In this study, we present an innovative approach leveraging combination internal resonances within a NEMS platform to generate mechanical soliton frequency combs (FCs) spanning a broad spectrum. In the time domain, the FCs take the form of a periodic train of narrow pulses, a highly coveted phenomenon within the realm of nonlinear wave-matter interactions. Our method relies on an intricate interaction among multiple vibration modes of a bracket-nanocantilever enabled by the strong nonlinearity of the electrostatic field. Through numerical simulation and experimental validation, we demonstrate that by amplifying the motions of the NEMS with the external electrostatic forcing tuned to excite the superharmonic resonance of order-n of the fundamental mode and exploiting combination internal resonances, we can generate multiple stable localized mechanical wave packets with different lobe sizes embodying soliton states I and II. This represents a significant breakthrough with profound implications for quantum computing and metrology.

2.
Med Educ ; 58(3): 354-362, 2024 03.
Artigo em Inglês | MEDLINE | ID: mdl-37726176

RESUMO

INTRODUCTION: Although programme evaluation is increasingly routinised across the academic health sciences, there is scant research on the factors that shape the scope and quality of evaluation work in health professions education. Our research addresses this gap, by studying how the context in which evaluation is practised influences the type of evaluation that can be conducted. Focusing on the context of accreditation, we critically examine the types of paradoxical tensions that surface as evaluation-leads consider evaluation ideals or best practices in relation to contextual demands associated with accreditation seeking. METHODS: Our methods were qualitative and situated within a critical realist paradigm. Study participants were 29 individuals with roles requiring responsibility and oversight on evaluation work. They worked across 4 regions, within 26 academic health science institutions. Data were collected using semi-structured interviews and analysed using framework and matrix analyses. RESULTS: We identified three overarching themes: (i) absence of collective coherence about evaluation practice, (ii) disempowerment of expertise and (iii) tensions as routine practice. Examples of these latter tensions in evaluation work included (i) resourcing accreditation versus resourcing robust evaluation strategy (performing paradox), (ii) evaluation designs to secure accreditation versus design to spur renewal and transformation (performing-learning paradox) and (iii) public dissemination of evaluation findings versus restricted or selective access (publicising paradox). Sub-themes and illustrative data are presented. DISCUSSION: Our study demonstrates how the high-stakes context of accreditation seeking surfaces tensions that can risk the quality and credibility of evaluation practices. To mitigate these risks, those who commission or execute evaluation work must be able to identify and reconcile these tensions. We propose strategies that may help optimise the quality of evaluation work alongside accreditation-seeking efforts. Critically, our research highlights the limitations of continually positioning evaluation purely as a method versus as a socio-technical practice that is highly vulnerable to contextual influences.


Assuntos
Acreditação , Aprendizagem , Humanos , Avaliação de Programas e Projetos de Saúde
3.
J Musculoskelet Neuronal Interact ; 24(1): 38-46, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38427367

RESUMO

BFR) applied during sprint interval training (SIT) on performance and neuromuscular function. METHODS: Fifteen men completed a randomized bout of SIT with CBFR, IBFR, and without BFR (No-BFR), consisting of 2, 30-s maximal sprints on a cycle ergometer with a resistance of 7.5% of body mass. Concentric peak torque (CPT), maximal voluntary isometric contraction (MVIC) torque, and muscle thickness (MT) were measured before and after SIT, including surface electromyography (sEMG) recorded during the strength assessments. Peak and mean revolutions per minute (RPM) were measured during SIT and power output was examined relative to physical working capacity at the fatigue threshold (PWCFT). RESULTS: CPT and MVIC torque decreased from pre-SIT (220.3±47.6 Nm and 355.1±72.5 Nm, respectively) to post-SIT (147.9±27.7 Nm and 252.2±45.5 Nm, respectively, all P<0.05), while MT increased (1.77±0.31 cm to 1.96±0.30 cm). sEMG mean power frequency decreased during CPT (-12.8±10.5%) and MVIC (-8.7±10.2%) muscle actions. %PWCFT was greater during No-BFR (414.2±121.9%) than CBFR (375.9±121.9%). CONCLUSION: SIT with or without BFR induced comparable alterations in neuromuscular fatigue and sprint performance across all conditions, without affecting neuromuscular function.


Assuntos
Treinamento Intervalado de Alta Intensidade , Músculo Esquelético , Humanos , Masculino , Eletromiografia , Contração Isométrica/fisiologia , Fadiga Muscular , Músculo Esquelético/fisiologia , Fluxo Sanguíneo Regional/fisiologia , Torque
4.
Eur J Appl Physiol ; 2024 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-39162881

RESUMO

PURPOSE: Resistance exercise can attenuate muscular impairments associated with multiple sclerosis (MS), and blood flow restriction (BFR) may provide a viable alternative to prescribing heavy training loads. The purpose of this investigation was to examine the progression of upper and lower body low-load (30% of one-repetition maximum [1RM]) resistance training (RT) with BFR applied intermittently during the exercise intervals (RT + BFR) versus volume-matched heavy-load (65% of 1RM) RT. METHODS: Men and women with MS (n = 16) were randomly assigned to low-load RT + BFR (applied intermittently) or heavy-load RT and completed 12 weeks (2 × /week) of RT that consisted of bilateral chest press, seated row, shoulder press, leg press, leg extension, and leg curl exercises. Exercise load, tonnage, and rating of perceived exertion were assessed at baseline and every 6 weeks. RESULTS: Training load increased to a greater extent and sometimes earlier for RT + BFR (57.7-106.3%) than heavy-load RT (42.3-54.3%) during chest press, seated row, and leg curl exercises, while there were similar increases (63.5-101.1%) for shoulder press, leg extension, and leg press exercises. Exercise tonnage was greater across all exercises for RT + BFR than heavy-load RT, although tonnage only increased during the chest press (70.7-80.0%) and leg extension (89.1%) exercises. Perceptions of exertion (4.8-7.2 au) and compliance (97.9-99.0%) were similar for both interventions. CONCLUSION: The training-induced increases in load, high compliance, and moderate levels of exertion suggested that RT + BFR and heavy-load RT are viable interventions among people with MS. RT + BFR may be a preferred modality if heavy loads are not well tolerated and/or to promote early-phase training responses.

5.
Int Orthop ; 48(5): 1351-1356, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38302595

RESUMO

In orthopaedic surgery, as well as other areas in medicine, it is common for a surgical technique to carry the original authors' name describing the procedure. The Judet family represents a unique history, since several orthopaedic procedures are known as "Judet's technique". The aim of this historic review is to outline the genealogy of the orthopaedic arm of the Judet family, while crediting each surgical procedure to the specific family member that described the technique.


Assuntos
Procedimentos Ortopédicos , Ortopedia , Humanos , Procedimentos Ortopédicos/efeitos adversos , Procedimentos Ortopédicos/métodos
6.
J Strength Cond Res ; 2024 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-39178106

RESUMO

ABSTRACT: Lubiak, SM, Lawson, JE, Gonzalez Rojas, DH, Proppe, CE, Rivera, PM, Hammer, SM, Trevino, MA, Dinyer-McNeely, TK, Montgomery, TR, Olmos, AA, Sears, KN, Bergstrom, HC, Succi, PJ, Keller, JL, and Hill, EC. A moderate blood flow restriction pressure does not affect maximal strength or neuromuscular responses. J Strength Cond Res XX(X): 000-000, 2024-The purpose of this study was to examine the acute effects of blood flow restriction (BFR) applied at 60% of total arterial occlusion pressure (AOP) on maximal strength. Eleven college-aged female subjects completed two testing sessions of maximal unilateral concentric, isometric, and eccentric leg extension muscle actions performed with and without BFR. Separate 3 (mode [isometric, concentric, eccentric]) × 2 (condition [BFR, no BFR]) × 2 (visit [2, 3]) repeated-measures analysis of variances were used to examine mean differences in maximal strength, neuromuscular function, rating of perceived exertion (RPE), and pain. For maximal strength (collapsed across condition and visit), isometric (128.5 ± 22.7 Nm) and eccentric (114.5 ± 35.4 Nm) strength were greater than concentric maximal strength (89.3 ± 22.3 Nm) (p < 0.001-0.041). Muscle excitation relative (%) to isometric non-BFR was greater during the concentric (108.6 ± 31.5%) than during the eccentric (86.7 ± 29.2%) (p = 0.045) assessments but not different than isometric (93.4 ± 17.9%) (p = 0.109) assessments, collapsed across condition and visit. For RPE, there was an interaction such that RPE was greater during non-BFR (4.3 ± 1.7) than during BFR (3.7 ± 1.7) (p = 0.031) during the maximal concentric strength assessments. Furthermore, during maximal strength assessments performed with BFR, isometric RPE (5.8 ± 1.9) was greater than concentric (3.7 ± 1.7) (p = 0.005) and eccentric (4.6 ± 1.9) (p = 0.009) RPE. Finally, pain was greater during the isometric (2.8 ± 2.1 au) than during the concentric (1.8 ± 1.5 au) (p = 0.016), but not eccentric, maximal strength assessments (2.1 ± 1.6 au) (p = 0.126), collapsed across condition and visit. The application of BFR at 60% AOP did not affect concentric, isometric, or eccentric maximal strength or neuromuscular function. Trainers, clinicians, and researchers can prescribe exercise interventions relative to a restricted (when using a moderate AOP) or nonrestricted assessment of maximal strength.

7.
J Interprof Care ; : 1-10, 2024 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-39264988

RESUMO

The shortage of adequately trained healthcare providers (HCPs) able to treat adults who have experienced childhood interpersonal trauma (CIT) is a pressing concern. This study explored HCPs' training needs for a trauma-focused psychoeducational group intervention and the potential barriers and facilitators to accessing such training. Three 1-hour focus group sessions were conducted with HCPs (n = 17) from two urban and one rural community healthcare organization serving diverse populations in Ontario, Canada, including under-housed people, women struggling with mental health and addiction, and LGBTQ+ populations. On average, participants had 2.4 years in their current role and 18.1 years of mental health field experience. Thematic analysis revealed key findings: a strong clinical need for trauma services, accessible training programs, and broadly applicable interventions relevant for diverse populations. Notably, participants emphasized the clinical advantages and increased accessibility of a virtual training programs focused on psychoeducational treatment interventions, particularly within community-based healthcare settings. This study highlights the potential of a virtual psychoeducational training programs for HCPs to address this critical gap in healthcare provision for individual with CIT. It also underscores the need to move beyond training program development and focus on implementation and sustainability of interventions in clinical practice.

8.
Artigo em Alemão | MEDLINE | ID: mdl-38153419

RESUMO

BACKGROUND: The need for a concept for the nationwide strategic transfer of critical care patients in Germany was highlighted during the COVID-19 (coronavirus disease 2019) pandemic. Despite the cloverleaf concept developed specifically for this purpose, the transfer of large numbers of critical care patients represents a major challenge. With the help of a computer simulation, the SCATTER research project uses a fictitious example to test, develop, and recommend transfer strategies. METHOD: The simulation was programmed after collecting procedural and structural data on critical care transports within Germany. The simulation allows altering various parameters and testing different transfer scenarios. In a fictitious scenario, nationwide transfers starting from Schleswig-Holstein were simulated and evaluated using predetermined criteria. RESULTS: In the case of ground-based transfers, it became apparent that, depending on the selected target region, not all patients could be transferred due to the limited range of ground-based vehicles. Although a higher number of patients can be transferred by air, this is associated with additional gurney changes and potential risk to the patient. A distance-dependent transport strategy led to the identical results as purely air-bound transport, since air-bound transport was always chosen due to the long distances. DISCUSSION: The simulation can be used to develop recommendations and to draw important conclusions from different transfer strategies.


Assuntos
COVID-19 , Cuidados Críticos , Humanos , Simulação por Computador , Alemanha , COVID-19/epidemiologia , Computadores
9.
J Ment Health ; : 1-10, 2024 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-38572918

RESUMO

BACKGROUND: The long-term mental and physical health implications of childhood interpersonal trauma on adult survivors is immense, however, there is a lack of available trauma-focused treatment services that are widely accessible. This study, utilizing a user-centered design process, sought feedback on the initial design and development of a novel, self-paced psychoeducation and skills-based treatment intervention for this population. AIMS: To explore the views and perspectives of adult survivors of childhood interpersonal trauma on the first two modules of an asynchronous trauma-focused treatment program. METHODS: Fourteen participants from our outpatient hospital service who completed the modules consented to provide feedback on their user experience. A thematic analysis of the three focus groups was conducted. RESULTS: Four major themes emerged from the focus groups: (1) technology utilization, (2) module content, (3) asynchronous delivery, and (4) opportunity for interactivity. Participants noted the convenience of the platform and the use of multimedia content to increase engagement and did not find the modules to be emotionally overwhelming. CONCLUSIONS: Our research findings suggest that an asynchronous virtual intervention for childhood interpersonal trauma survivors may be a safe and acceptable way to provide a stabilization-focused intervention on a wider scale.

10.
Med Educ ; 57(12): 1210-1218, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37264487

RESUMO

INTRODUCTION: The COVID-19 pandemic had significant impacts on many aspects of health care and education, including the accreditation of medical education programmes. As a community of international educators, it is important that we study changes that resulted from the pandemic to help us understand educational processes more broadly. As COVID-19 unfolded in Canada, a revised format of undergraduate medical accreditation was implemented, including a shift to virtual site visits, a two-stage visit schedule, a focused approach to reviewing standards and the addition of a field secretary to the visit team. Our case study research aimed to evaluate the sociomaterial implications of these changes in format on the process of accreditation at two schools. METHODS: We interviewed key informants to understand the impacts, strengths and limitations of changes made to the accreditation format. We used an abductive approach to analyse transcripts and applied a sociomaterial lens in looking for interconnections between the material and social changes that were experienced within the accreditation system. RESULTS: Stakeholders within the accreditation system did not anticipate that changes to the accreditation format would have significant impacts on how accreditation functioned or on its overall outcomes. However, key informants described how the revised format of accreditation reconstructed how power was distributed and how knowledge was produced. The revised format contributed to changes in who held power within each of the programmes, within each of the visiting teams and between site members and visiting team members. As power shifted across stakeholders in response to material changes to the accreditation format, key informants described changes in how knowledge was produced. CONCLUSIONS: Our findings suggest that the most powerful knowledge about any given programme might best be obtained through individualised tools, technologies and voices that are most meaningful to the unique context of each programme. Deliberate attention to how knowledge and power are influenced by the interactions between material and social processes within accreditation may help educators and leaders see the effects of change.


Assuntos
COVID-19 , Educação Médica , Humanos , Pandemias , Faculdades de Medicina , COVID-19/epidemiologia , Acreditação
11.
J Musculoskelet Neuronal Interact ; 23(2): 165-174, 2023 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-37259656

RESUMO

OBJECTIVES: The purpose of this investigation was to examine the acute effects of low-load blood flow restriction (LLBFR) and low-load (LL) resistance exercise on muscle excitation, neuromuscular efficiency, and average torque. METHODS: Eleven men (age±SD=22±3yrs) randomly performed LLBFR and LL that consisted of 30 unilateral leg extensions at 30% of one-repetition maximum while surface electromyography (sEMG) and torque were simultaneously assessed. Polynomial regression analyses and slope comparisons were performed to examine patterns of responses and rates of change. RESULTS: sEMG amplitude increased for LLBFR (9 of 11) and LL (8 of 11) and between composite responses (R2=0.939-0.981). For LLBFR, sEMG amplitude increased to a greater extent for 5 of the 11 individual and for the composite responses. Similarly, neuromuscular efficiency decreased for LLBFR (8 of 11) and LL (5 of 11) as well as the composite responses r2=0.902-0.929, but the decrease was larger for LLBFR than LL for the individual (4 of 11) responses. For average submaximal concentric torque, there were individual increases, decreases, and no changes for the composite responses (R2=0.198-0.325). CONCLUSION: LLBFR elicited greater fatigue-induced increases in muscle excitation and decreases in neuromuscular efficiency than LL, but neither LLBFR nor LL affected average submaximal concentric torque.


Assuntos
Músculo Esquelético , Treinamento Resistido , Humanos , Masculino , Eletromiografia , Exercício Físico/fisiologia , Músculo Esquelético/fisiologia , Torque , Adulto Jovem , Adulto
12.
Nano Lett ; 22(8): 3196-3203, 2022 04 27.
Artigo em Inglês | MEDLINE | ID: mdl-35404606

RESUMO

A resonant microcantilever sensor is fabricated from a zinc oxide (ZnO) thin film, which serves as both the structural and sensing layers. An open-air spatial atomic layer deposition technique is used to deposit the ZnO layer to achieve a ∼200 nm thickness, an order of magnitude lower than the thicknesses of conventional microcantilever sensors. The reduction in the number of layers, in the cantilever dimensions, and its overall lower mass lead to an ultrahigh sensitivity, demonstrated by detection of low humidity levels. A maximum sensitivity of 23649 ppm/% RH at 5.8% RH is observed, which is several orders of magnitude larger than those reported for other resonant humidity sensors. Furthermore, the ZnO cantilever sensor is self-actuated in air, an advantageous detection mode that enables simpler and lower-power-consumption sensors.


Assuntos
Óxido de Zinco , Umidade , Óxido de Zinco/química
13.
J Strength Cond Res ; 37(10): e546-e554, 2023 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-37639655

RESUMO

ABSTRACT: Wizenberg, AM, Gonzalez-Rojas, D, Rivera, PM, Proppe, CE, Laurel, KP, Stout, JR, Fukuda, DH, Billaut, F, Keller, JL, and Hill, EC. Acute effects of continuous and intermittent blood flow restriction on sprint interval performance and muscle oxygen responses. J Strength Cond Res 37(10): e546-e554, 2023-This investigation aimed to examine the acute effects of continuous and intermittent blood flow restriction (CBFR and IBFR, respectively) during sprint interval training (SIT) on muscle oxygenation, sprint performance, and ratings of perceived exertion (RPE). Fifteen men (22.6 ± 2.4 years; 176 ± 6.3 cm; 80.0 ± 12.6 kg) completed in random order a SIT session with CBFR, IBFR (applied during rest), and no blood flow restriction (NoBFR). Each SIT session consisted of two 30-second all-out sprint tests separated by 2 minutes. Peak power (PP), total work (TW), sprint decrement score (S dec ), RPE, and muscle oxygenation were measured during each sprint. A p value ≤0.05 was considered statistically significant. PP decreased to a greater extent from sprint 1 to sprint 2 during CBFR (25.5 ± 11.9%) and IBFR (23.4 ± 9.3%) compared with NoBFR (13.4 ± 8.6%). TW was reduced similarly (17,835.6 ± 966.2 to 12,687.2 ± 675.2 J) from sprint 1 to sprint 2 for all 3 conditions, but TW was lower (collapsed across time) for CBFR (14,320.7 ± 769.1 J) than IBFR (15,548.0 ± 840.5 J) and NoBFR (15,915.4 ± 771.5 J). There were no differences in S dec (84.3 ± 1.7%, 86.1 ± 1.5%, and 87.2 ± 1.1% for CBFR, IBFR, and NoBFR, respectively) or RPE, which increased from sprint 1 (8.5 ± 0.3) to sprint 2 (9.7 ± 0.1). Collective muscle oxygenation responses increased across time and were similar among conditions, whereas increases in deoxy[heme] and total[heme] were greatest for CBFR. Applying BFR during SIT induced greater decrements in PP, and CBFR resulted in greater decrements in work across repeated sprints. The larger increases in deoxy[heme] and total[heme] for CBFR suggested it may induce greater metabolite accumulation than IBFR and NoBFR when combined with SIT.


Assuntos
Treinamento Intervalado de Alta Intensidade , Músculos , Humanos , Masculino , Heme , Oxigênio , Descanso , Adulto Jovem
14.
J Neurophysiol ; 128(1): 73-85, 2022 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-35704398

RESUMO

The purpose of this study was to examine the acute effects of low-load blood flow restriction (LLBFR) and low-load non-BFR (LL) on neuromuscular function after a bout of standardized fatiguing leg extension muscle actions. Fourteen men (mean age ± SD = 23 ± 4 yr) volunteered to participate in this investigation and randomly performed LLBFR and LL on separate days. Resistance exercise consisted of 75 isotonic unilateral leg extension muscle actions performed at 30% of one-repetition maximum. Before (pretest) and after (posttest) performance of each bout of exercise, strength and neural assessments were determined. There were no pretest to posttest differences between LLBFR and LL for maximal voluntary isometric contraction (MVIC) torque or V wave/M wave responses (muscle compound action potentials assessed during a superimposed MVIC muscle action), which exhibited decreases (collapsed across condition) of 41.2% and 26.2%, respectively. There were pretest to posttest decreases in peak twitch torque (36.0%) and surface electromyography amplitude (sEMG) (29.5%) for LLBFR but not LL and larger decreases in voluntary activation for LLBFR (11.3%) than for LL (4.5%). These findings suggested that LLBFR elicited greater fatigue-induced decreases in several indexes of neuromuscular function relative to LL. Despite this, both LLBFR and LL resulted in similar decrements in performance as assessed by maximal strength.NEW & NOTEWORTHY The application of blood flow restriction induces greater acute neuromuscular fatigue relative to nonrestricted conditions. Resistance exercise with blood flow restriction elicited a greater reduction in twitch responses. These neuromuscular differences might explain the more favorable adaptations achieved with blood flow restriction that are likely a function of metabolic stress and subsequent changes in efferent neural drive.


Assuntos
Fadiga Muscular , Treinamento Resistido , Humanos , Contração Isométrica/fisiologia , Masculino , Fadiga Muscular/fisiologia , Músculo Esquelético/fisiologia , Fluxo Sanguíneo Regional/fisiologia , Treinamento Resistido/métodos , Torque
15.
Small ; 18(19): e2106006, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35195360

RESUMO

Transparent electrodes (TEs) are pivotal components in many modern devices such as solar cells, light-emitting diodes, touch screens, wearable electronic devices, smart windows, and transparent heaters. Recently, the high demand for flexibility and low cost in TEs requires a new class of transparent conductive materials (TCMs), serving as substitutes for the conventional indium tin oxide (ITO). So far, ITO has been the most used TCM despite its brittleness and high cost. Among the different emerging alternative materials to ITO, metallic nanomaterials have received much interest due to their remarkable optical-electrical properties, low cost, ease of manufacturing, flexibility, and widespread applicability. These involve metal grids, thin oxide/metal/oxide multilayers, metal nanowire percolating networks, or nanocomposites based on metallic nanostructures. In this review, a comparison between TCMs based on metallic nanomaterials and other TCM technologies is discussed. Next, the different types of metal-based TCMs developed so far and the fabrication technologies used are presented. Then, the challenges that these TCMs face toward integration in functional devices are discussed. Finally, the various fields in which metal-based TCMs have been successfully applied, as well as emerging and potential applications, are summarized.


Assuntos
Nanoestruturas , Nanofios , Condutividade Elétrica , Eletrodos , Metais/química , Nanofios/química , Óxidos
16.
Sensors (Basel) ; 22(13)2022 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-35808503

RESUMO

Many systems with distributed dynamics are described by partial differential equations (PDEs). Coupled reaction-diffusion equations are a particular type of these systems. The measurement of the state over the entire spatial domain is usually required for their control. However, it is often impossible to obtain full state information with physical sensors only. For this problem, observers are developed to estimate the state based on boundary measurements. The method presented applies the so-called modulating function method, relying on an orthonormal function basis representation. Auxiliary systems are generated from the original system by applying modulating functions and formulating annihilation conditions. It is extended by a decoupling matrix step. The calculated kernels are utilized for modulating the input and output signals over a receding time window to obtain the coefficients for the basis expansion for the desired state estimation. The developed algorithm and its real-time functionality are verified via simulation of an example system related to the dynamics of chemical tubular reactors and compared to the conventional backstepping observer. The method achieves a successful state reconstruction of the system while mitigating white noise induced by the sensor. Ultimately, the modulating function approach represents a solution for the distributed state estimation problem without solving a PDE online.


Assuntos
Algoritmos , Simulação por Computador , Difusão
17.
Eur J Orthop Surg Traumatol ; 32(2): 371-376, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33783628

RESUMO

Hip and groin pain in patients at-risk for femoral neck stress fracture demand a careful workup including advanced imaging in the setting of normal radiographs. A delay in diagnosis can lead to fracture displacement, which negatively impacts outcomes. Non-displaced tension-sided fractures and displaced fractures warrant operative fixation, while non-displaced compression-side fractures can be managed conservatively. Fixation with a sliding hip screw or cephalomedullary nail is recommended over cannulated screws. In addition, all patients should undergo a metabolic workup to identify correctable parameters. We present a rare case of bilateral compression-sided basicervical femoral neck stress fractures in a non-compliant osteoporotic patient who was treated with cannulated screws. The postoperative course was complicated by bilateral subtrochanteric stress riser fractures requiring revision fixation, which could have been prevented with use of a different implant.


Assuntos
Fraturas do Colo Femoral , Fraturas de Estresse , Parafusos Ósseos/efeitos adversos , Fraturas do Colo Femoral/diagnóstico por imagem , Fraturas do Colo Femoral/etiologia , Fraturas do Colo Femoral/cirurgia , Colo do Fêmur , Fixação Interna de Fraturas/efeitos adversos , Fraturas de Estresse/diagnóstico por imagem , Fraturas de Estresse/etiologia , Humanos
18.
Small ; 17(21): e2007344, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33825334

RESUMO

Threshold switching devices are fundamental active elements in more than Moore approaches, integrating the new generation of non-volatile memory devices. Here, the authors report an in-plane threshold resistive switching device with an on/off ratio above 106 , a low resistance state of 10 to 100 kΩ and a high resistance state of 10 to 100 GΩ. Our devices are based on nanocomposites of silver nanowire networks and titanium oxide, where volatile unipolar threshold switching takes place across the gap left by partially spheroidized nanowires. Device reversibility depends on the titanium oxide thickness, while nanowire network density determines the threshold voltage, which can reach as low as 0.16 V. The switching mechanism is explained through percolation between metal-semiconductor islands, in a combined tunneling conduction mechanism, followed by a Schottky emission generated via Joule heating. The devices are prepared by low-cost, atmospheric pressure, and scalable techniques, enabling their application in printable, flexible, and transparent electronics.

19.
Nanotechnology ; 32(44)2021 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-34374663

RESUMO

Silver nanowire (AgNW) networks are among the most promising indium-free, flexible transparent electrodes for energy, lighting and heating devices. However, the lack of stability of such networks is a key factor that limits their industrial application. While applications require homogeneous networks, non-homogeneous AgNW networks are intentionally prepared in the present work to probe the mechanisms leading to failure under electrical stress. We show that induced non-homogeneities have a strong impact both on the spatial distribution of temperature (measured by IR imaging) and the current density throughout the electrode (as deduced from modeling). Regions with higher current density under elevated electrical stress are correlated to the origin of degradation. Furthermore, the influence of a zinc oxide (ZnO) layer on electrical performances of non-homogeneous specimens is studied. Thanks to ZnO coating, the tortuosity of electrical potential lines measured by the one-probe mapping technique is much lower than for bare networks. Additionally, coated network electrical failure occurs at 40% higher voltage compared to bare network, over 18 V, while reaching superior power-induced heating of 360 °C. The results presented here will contribute to the design and fabrication of more robust nanowire networks, particularly for application in transparent heaters.

20.
BMC Musculoskelet Disord ; 21(1): 251, 2020 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-32303230

RESUMO

BACKGROUND: This study aimed to evaluate the effects of vitamin D deficiency on the functional outcomes following a high tibial osteotomy (HTO). METHODS: Clinical data of 209 patients (327 knees) who underwent HTO done by a single surgeon were retrospectively registered for the study. Ninety-four patients (94 knees) who underwent HTO were analyzed. Patients were assigned into two groups according to their preoperative serum vitamin D levels (D- Deficiency and S- Sufficient); < 20 ng/ml (group D, N = 48) and ≥ 20 ng/ml (group S, N = 46) respectively. A subjective form of International Knee Documentation Committee (IKDC) score, mechanical alignment, and cartilage status before and 1 year following HTO were studied between groups. RESULTS: The mean postoperative IKDC score was significantly higher in group S (p = 0.012). Moreover, the difference of IKDC score between pre- and post- HTO was also significantly higher in group S (p = 0.006). Preoperative vitamin D level and IKDC score did not show a significant correlation. Serum vitamin D level was found to be moderately correlated to postoperative IKDC score (r = 0.342 and, p = 0.001). A moderately positive correlation between serum vitamin D level and improvement of IKDC score following osteotomy was appreciated (r = 0.381 and, p < 0.001). CONCLUSION: Patients with vitamin D deficiency had less satisfactory functional outcomes within 1 year from HTO surgery. Our results suggest that preoperative serum vitamin D level is one of the factors affecting the outcome after HTO. We recommended analyzing serum vitamin D levels as part of the routine workup in patients undergoing HTO.


Assuntos
Osteoartrite do Joelho/complicações , Osteoartrite do Joelho/cirurgia , Osteotomia/métodos , Período Pré-Operatório , Tíbia/cirurgia , Deficiência de Vitamina D/complicações , Vitamina D/análogos & derivados , Idoso , Placas Ósseas , Cartilagem Articular/fisiopatologia , Estudos de Casos e Controles , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Osteoartrite do Joelho/sangue , Estudos Retrospectivos , Resultado do Tratamento , Vitamina D/sangue
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