Single Contact Research Articles

Cardiovascular Response to Intraneural Right Vagus Nerve Stimulation in Adult Minipig

ObjectiveThis study explored intraneural stimulation of the right thoracic vagus nerve (VN) in sexually mature male minipigs to modulate safe heart rate and blood pressure response. Material and MethodsWe employed an intraneural electrode designed for the VN of pigs to perform VN stimulation (VNS). This was delivered using different numbers of contacts on the electrode and different stimulation parameters (amplitude, frequency, and pulse width), identifying the most suitable stimulation configuration. All the parameter ranges had been selected from a computational cardiovascular system model. ResultsClinically relevant responses were observed when stimulating with low current intensities and relatively low frequencies delivered with a single contact. Selecting a biphasic, charge-balanced square wave for VNS with a current amplitude of 500 μA, frequency of 10 Hz, and pulse width of 200 μs, we obtained heart rate reduction of 7.67 ± 5.19 beats per minute, systolic pressure reduction of 5.75 ± 2.59 mmHg, and diastolic pressure reduction of 3.39 ± 1.44 mmHg. ConclusionHeart rate modulation was obtained without inducing any observable adverse effects, underlining the high selectivity of the intraneural approach.

Ultrahigh Color Conversion Efficiency Nano-Light-Emitting Diode With Single Electrical Contact

Realizing full color GaN-based micro- and nano-light-emitting diode (nLED) displays with quantum dots (QDs) being the color conversion media remains challenging because of the limited QD color conversion efficiency (CCE). In this article, by using GaN-based nanorod LED as the light source and exciting the QDs by nonradiative energy transfer (NRET) method, a nanorod LED with ultrahigh CCE has been realized. At the same time, a single electrical contact alternating current (ac)-driven electroluminescence (EL) method is adopted to investigate the relationship between frequency and nLED performance. Different from the double terminal injection mode, on the premise of lighting up the nanorod LED, the ac-driven can also avoid the necessity of external p-type and n-type electrodes, thus simplified the manufacturing process of LED. The final optical measurement shows that the CCE of this hybrid color conversion nLED driven by single contact electrode can reach up to 86.67% under the ac voltage of 60 V and an ac frequency of 14.2 MHz, which shows that the energy utilization efficiency can be effectively improved by NRET.

Dominant Mechanism of GaN-Based Single Contact Micro-LED Driven by AC Power

A new type of Micro-LED driving technique has attracted wide attention, for its advantages and potential applications in the field where direct current-drive (DC-drive) LED is restricted. However, the understanding of the dominant mechanism in AC-driven LED is still vague. In this work, AC-driven single contact LED (SC-LED) devices were fabricated. Electrical and optical characteristics are investigated. A new equivalent circuit model is established and simulated. The injection efficiency (INJ) is discussed, which understands the dominant mechanism of AC-driven SC-LEDs. These results could promote the applications of AC-driven Micro-LED devices in the future.

Possibility of mpox viral transmission and control from high-risk to the general population: a modeling study

BackgroundMpox is an emerging infectious disease that is now a global hazard. The strategies for preventing and controlling mpox should be further investigated in terms of transmission characteristics, infection risk among different populations, and ideal therapeutic approaches.MethodsA multi-group dynamic model was used to quantify the transmissibility of mpox. We further analyzed the transmission risk from men who have sex with men (MSM) to non-MSM and evaluated the effects of three intervention measures, including community-based prevention, early detection, and vaccination.ResultsThe median value of effective reproduction number (Reff) and probability of contact via a single contact (q) among MSM worldwide is 3.11 (interquartile range [IQR]: 2.82–5.57) and 2.15% (IQR: 1.95–3.84%). We found that the cumulative incidence rate of non-MSM is much lower than that of MSM (< 1/2048) when the possibility of infection (including the percentage of high-risk behaviors of contact degree [C] and q) was lowered to less than 1 in 100,000. When comparing the three intervention measures, if we want to control the cumulative incidence rate to 5.96 × 10–8 we need to increase the vaccine coverage to 81% or reduce the transmission rate factor (Cq) to 70% or shorten the transmission period to 74%.ConclusionsMpox has high transmissibility in MSM, which required minimize the risk of infection and exposure to high-risk populations. Community prevention and control is the top priority of interventions to contain the spread of mpox.

How Does Network Structure Impact Socially Reinforced Diffusion?

How does network structure impact the speed and reach of social contagions? The current view holds that random links facilitate “simple” contagion, but when agents require multiple reinforcements for “complex” adoption, clustered networks are better conduits of social influence. We show that in complex contagion, even low probabilities of adoption upon a single contact would activate an exponential contagion process that tilts the balance in favor of random networks. On the other hand, underappreciated but critical to the race between random and clustered networks is how long agents engage with contagion. Switching back to prior practice and the inactivation of senders and especially receivers shorten the window of engagement for convincing distant contacts and weaken the reach of diffusion on random networks. We propose a simplified framework where clustering primarily enables contagion when repetition matters and receivers lose interest quickly; otherwise, diffusion, simple or complex, is faster on random networks than clustered ones. These mechanisms can inform designing social networks, structuring groups, and seeding of ideas and innovations at a time when the increasing inflow of content from various media limits actors’ engagement with each item, whereas expanding network size and connections speeds up diffusion through distant contacts. Supplemental Material: The e-companion is available at https://doi.org/10.1287/orsc.2023.1658 .

Phenomenological Laws of Single Point Contact: Pre-Rolling Contact Resistance through Pendulum

The development results of a single-point contact system set up as a pendulum to study the laws of rolling resistance to contacting bodies at a distance significantly reduced compared to the elastic contact spot size. The designed device uses a physical pendulum sustained by only one ball on a flat polished surface. The problem of stability of the pendulum swing plane is solved. A phenomenological theory of rolling resistance is described. The surface tension of solids on the contact zone, parameters of the frequency-independent internal friction and the pressure of the adhesion forces are found.

Curvature-based force estimation for an elastic tube

AbstractContact force is one of the most significant feedback for robots to achieve accurate control and safe interaction with environment. For continuum robots, it is possible to estimate the contact force based on the feedback of robot shapes, which can address the difficulty of mounting dedicated force sensors on the continuum robot body with strict dimension constraints. In this paper, we use local curvatures to estimate the magnitude and location of single or multiple contact forces based on Cosserat rod theory. We validate the proposed method in a thin elastic tube and calculate the curvatures via Fiber Bragg Grating (FBG) sensors or image feedback. For the curvature feedback obtained from multicore FBG sensors, the overall force magnitude estimation error is$0.062 \pm 0.068$N and the overall location estimation error is$3.51 \pm 2.60$mm. For the curvature feedback obtained from image, the overall force magnitude estimation error is$0.049 \pm 0.048$N and the overall location estimation error is$2.75 \pm 1.71$mm. The results demonstrate that the curvature-based force estimation method is able to accurately estimate the contact force.

Specific Signal Enhancement on an RNA-Protein Interface by Dynamic Nuclear Polarization.

Sensitivity and specificity are both crucial for the efficient solid-state NMR structure determination of large biomolecules. We present an approach that features both advantages by site-specific enhancement of NMR spectroscopic signals from the protein-RNA binding site within a ribonucleoprotein (RNP) by dynamic nuclear polarization (DNP). This approach uses modern biochemical techniques for sparse isotope labeling and exploits the molecular dynamics of 13 C-labeled methyl groups exclusively present in the protein. These dynamics drive heteronuclear cross relaxation and thus allow specific hyperpolarization transfer across the biomolecular complex's interface. For the example of the L7Ae protein in complex with a 26mer guide RNA minimal construct from the box C/D complex in archaea, we demonstrate that a single methyl-nucleotide contact is responsible for most of the polarization transfer to the RNA, and that this specific transfer can be used to boost both NMR spectral sensitivity and specificity by DNP.

Investigation on Arc Asynchronous Characteristics of the Double Bridge-Type Contacts in DC Relays

The asynchrony of the multi-break dc relay has an important influence on its arcing characteristics. Through the experimental test platform, the arc characteristics of the single bridge-type contact and the double bridge-type contacts are compared. Arc images are acquired through high-speed photography. On the basis of asynchronous action, the influence of action speed and overtravel difference on arcing characteristics is analyzed. A multi-breakpoint asynchronous arc model is established to study the nonlinear relationship between overtravel difference and arc duration. The distribution characteristics of the double-bridge arc are analyzed. Experiments and simulations show that the double bridge-type contacts have better arc-extinguishing characteristics. Increasing breaking speed is conducive to reducing arc energy difference between fractures. When the overtravel difference is small, the bridge <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$B$</tex-math> </inline-formula> (bridge with larger overtravel) arc can enter the diffusion state, and the arc voltage of bridge <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$B$</tex-math> </inline-formula> is higher. Reducing the overtravel difference can effectively reduce the arc duration.

Recent Advancements and Future Trends in Indirect Bridge Health Monitoring

Bridges hold an imperative role in the transportation network and infrastructure. Continuous monitoring of their condition is crucial for the efficient operation of transportation facilities. Conventional bridge monitoring has relied on direct sensor instrumentation on the bridge to obtain the bridge response. Indirect bridge health monitoring (iBHM) leverages the moving traffic over the specific bridge of interest. The benefit of iBHM lies in the fact that bridge instrumentation is no longer required since the moving vehicle is instrumented with sensors. The collected data can be used to identify the dynamic characteristics of the bridge. Additionally, the method can be used to detect damage using the information of the vehicle bridge interaction. This paper systematically reviews the recent research progress in iBHM, and the review is organized based on four main groups, namely single test vehicles, tractor-trailer vehicles, crowdsourced/smartphone monitoring, and contact point (CP) response. The primary classification is further divided according to the nature of the investigation, which includes theoretical and numerical investigations, laboratory tests, and full-scale validations. After a concise and systematic review, the existing challenges and future recommendations are outlined. It is anticipated that this review will provide valuable guidance for researchers and practitioners of bridge engineering to understand better the evolution, development, and future trends of iBHM.

Effect of shear-induced contact area and aperture variations on nonlinear flow behaviors in fractal rock fractures

This study experimentally analyzes the nonlinear flow characteristics and channelization of fluid through rough-walled fractures during the shear process using a shear-flow-visualization apparatus. A series of fluid flow and visualization tests is performed on four transparent fracture specimens with various shear displacements of 1 mm, 3 mm, 5 mm, 7 mm and 10 mm under a normal stress of 0.5 MPa. Four granite fractures with different roughnesses are selected and quantified using variogram fractal dimensions. The obtained results show that the critical Reynolds number tends to increase with increasing shear displacement but decrease with increasing roughness of fracture surface. The flow paths are more tortuous at the beginning of shear because of the wide distribution of small contact spots. As the shear displacement continues to increase, preferential flow paths are more distinctly observed due to the decrease in the number of contact spots caused by shear dilation; yet the area of single contacts increases. Based on the experimental results, an empirical mathematical equation is proposed to quantify the critical Reynolds number using the contact area ratio and fractal dimension. • A visualization method is developed to determine the channelization of sheared fracture. • A model for predicting the Re c is proposed.

Tribological properties of oil-impregnated polyimide in double-contact friction under micro-oil lubrication conditions

Oil-impregnated porous polyimide (iPPI) materials are usually used as retainer for bearings. In these bearings, balls and rings, balls and retainers are two different kinds of contact. In this paper, the friction and wear properties of iPPI were investigated using steel (disc)—steel (ball)—iPPI (pin) double-contact friction test rig for simulating the actual contact in bearings. The results show that compared with that of iPPI—steel single contact, the friction coefficient of iPPI—steel in double contacts is lower and decreases with the amount of additional oil. The surface of iPPI in single contact suffers more wear compared with that in double contacts. Different from single contact, the worn surfaces of iPPI in double contacts are blackened. The Raman spectra of worn surfaces of balls and discs indicate that α-Fe2O3 and Fe3O4 were formed during rubbing of the double contacts. Many nanoscale iron oxide particles are found on the worn surfaces of iPPI in double contacts; on the contrary, few particles could be found on the surface in single contact. In double-contact friction, the nanoscale wear debris penetrates inside the iPPI material through the process of extruding and recycling of oil, which is the mechanism of the blackening of the iPPI worn surfaces. The studies show that the double-contact friction method is a new and effective method to study the friction in bearings, especially for those with polymer retainer.

Integrated multimodality microscope for accurate and efficient target-guided cryo-lamellae preparation

Cryo-electron tomography (cryo-ET) is a revolutionary technique for resolving the structure of subcellular organelles and macromolecular complexes in their cellular context. However, the application of the cryo-ET is hampered by the sample preparation step. Performing cryo-focused ion beam milling at an arbitrary position on the sample is inefficient, and the target of interest is not guaranteed to be preserved when thinning the cell from several micrometers to less than 300 nm thick. Here, we report a cryogenic correlated light, ion and electron microscopy (cryo-CLIEM) technique that is capable of preparing cryo-lamellae under the guidance of three-dimensional confocal imaging. Moreover, we demonstrate a workflow to preselect and preserve nanoscale target regions inside the finished cryo-lamellae. By successfully preparing cryo-lamellae that contain a single centriole or contact sites between subcellular organelles, we show that this approach is generally applicable, and shall help in innovating more applications of cryo-ET.

Contact tracing & super-spreaders in the branching-process model

In recent years, it became clear that super-spreader events play an important role, particularly in the spread of airborne infections. We investigate a novel model for super-spreader events, not based on a heterogeneous contact graph but on a random contact rate: Many individuals become infected synchronously in single contact events. We use the branching-process approach for contact tracing to analyze the impact of super-spreader events on the effect of contact tracing. Here we neglect a tracing delay. Roughly speaking, we find that contact tracing is more efficient in the presence of super-spreaders if the fraction of symptomatics is small, the tracing probability is high, or the latency period is distinctively larger than the incubation period. In other cases, the effect of contact tracing can be decreased by super-spreaders. Numerical analysis with parameters suited for SARS-CoV-2 indicates that super-spreaders do not decrease the effect of contact tracing crucially in case of that infection.

Accuracy of radiological prediction of electrode position with otological planning software and implications of high-resolution imaging

Objectives In cochlear implantation, preoperative prediction of electrode position has recently gained increasing attention. Currently, planning is usually done by multislice CT (MSCT). However, flat-panel volume CT (fpVCT) and its secondary reconstructions (fpVCTSECO) allow for more precise visualization of the cochlea. Combined with a newly developed otological planning software, the position of every single contact can be effectively predicted. In this study it was investigated how accurately radiological prediction forecasts the postoperative electrode localization and whether higher image resolution is advantageous. Methods Utilizing otological planning software (OTOPLAN®️) and different clinical imaging modalities (MSCT, fpVCT and fpVCTSECO) the electrode localization [angular insertion depth (AID)] and respective contact frequencies were predicted preoperatively and examined postoperatively. Furthermore, inter-electrode-distance (IED) and inter-electrode-frequency difference (IEFD) were evaluated postoperatively. Results Measurements revealed a preoperative overestimation of AID. Corresponding frequencies were also miscalculated. Determination of IED and IEFD revealed discrepancies at the transition from the basal to the middle turn and round window to the basal turn. All predictions and discrepancies were lowest when using fpVCTSECO. Conclusion The postoperative electrode position can be predicted quite accurately using otological planning software. However, because of several potential misjudgments, high-resolution imaging, such as offered by fpVCTSECO, should be used pre- and postoperatively.

Effect of Contact Area on Deflection Flow Behavior in a Bifurcated Fracture

The factors affecting the deflection flow in a bifurcated fracture under the effect of the fracture contact area are discussed. The effects of the contact area and cross-section on the deflection flow are determined using a combination of experiments and numerical simulations. The contact and seepage changes in bifurcated fractures under a confining pressure are monitored using a pressure film. A parallel plate bifurcated fracture model with a single contact area is established, which is in good agreement with the results of the laboratory experiments. Based on numerical simulation experiments, under the effects of the contact area and cross-section, the change in the effective flow path is the main reason for the change in the deflection flow behavior. The proportion of the flow path of the entire fracture is used to reflect the deflection flow characteristics under different contact areas and cross-sectional areas. For a given contact area, the larger the cross-section of the contact area, the larger the difference in the outlet flow of the bifurcated fracture and the more obvious the deflection flow behavior. As the contact area increases and the cross-section is constant, the effective path of the fluid does not change, and the deflection flow behavior does not change. This explanation of the cause of fracture deflection flow is of great significance for studying fracture seepage.

New Zealanders with low back pain seeking health care: a retrospective descriptive analysis of Accident Compensation Corporation-funded low back pain healthcare service usage.

Introduction Most New Zealanders experience low back pain (LBP) at least once throughout their lifetime and many seek help from the large range of health providers in primary care. Accident Compensation Corporation (ACC) funds a significant proportion of those claims, but which services are they funding and what are the costs? Method This was a retrospective audit and descriptive analysis of ACC-funded, non-public hospital healthcare service use by people with LBP in New Zealand (NZ). Outcome measures were the healthcare services accessed by people with ACC-funded LBP,the claims (all occurrences for a service that has generated a payment/year), single contact (with a service), and costs (NZ$) for services between 2009 and 2020. Results The number of claims for services were 129 000 for physiotherapy, 105 000 for general practitioner and 59 000 for radiology services. Per single contact, elective surgery and radiology services were the most expensive. During 2009-2020, there were 3.3 million ACC claims for LBP with a total cost of NZ$4 billion. Over this time, there was an increase in claims, costs and single contacts. Costs decreased slightly during 2010 due to changes in healthcare funding and in 2020 due to the COVID-19 pandemic. Discussion Consumers have considerable choice in where they access health care for ACC-funded LBP services. This study shows the services they use most frequently and the cost to NZ for those services. These data can inform service planning for ACC-funded LBP health care in NZ.

Insights into the influence on 2,4,6-trichlorophenol microbial reductive dechlorination process by exposure to microplastics

As a newly emerging pollutant, the adverse effects of ubiquitous microplastic on ecosystems and living have attracted increasing attention, however, the microplastic intervention influencing anaerobic biotransformation behaviors of chlorinated aromatics remains poorly understood. Here, the significantly altered 2,4,6-trichlorophenol microbial reductive dechlorination activities were found by single- and multi-exposure to microplastics. Single contact with five different types of microplastics showed diverse dechlorination performance, that PET was the most promoted ( k T of 0.037 h -1 ) and PP was the largest inhibited ( k T of 0.01 h -1 ) compared to control ( k T of 0.023 h -1 ). The microplastic size was negatively correlated with dechlorination activities, with 1.8~1.9 times decreased k T as the particle size decreased from 1000μm to 75μm. The higher the concentration, the more promoted effects by PET and the more inhibited effects by PP on dechlorination performance, with the respective k T of 0.052 h -1 and 0.006 h -1 under 2.0 g/L condition. Bio-enrichment on hydrophilic surfaces of microplastics (e.g. PET) was speculated to be responsible for the favored dechlorination activity, while adsorption of chlorophenols posed little influence. However, the overall inhibited 2,4,6-TCP dechlorination performance was found under all conditions by extending exposure cycles. The obvious bacterial succession that the abundance of some absolute anaerobic fermentator ( Dysgonomonas ) or dechlorinator ( Desulfitobacterium ) was greatly decreased, while, some facultative anaerobic genera ( Comamonas , Pseudomonas ) that held microplastic degradation potential were enriched. The increased positive correlations among networks were found and the more simplified molecule network as the size of microplastics became larger. The study provided significant theoretical support for understanding anaerobic biotransformation process of CAs influenced by the microplastic intervention. • Altered microbial reductive dechlorination activities by microplastic intervention • PET mostly promoted and PP largest inhibited the dechlorination by single contact • Microplastic size was negatively correlated with the dechlorination activities • Serious inhibited dechlorination performance was found by multi-cycle exposure • Obvious population succession and increased positive correlations of eco-networks

Microscale multicircuit brain stimulation: Achieving real-time brain state control for novel applications.

Neurological and psychiatric disorders typically result from dysfunction across multiple neural circuits. Most of these disorders lack a satisfactory neuromodulation treatment. However, deep brain stimulation (DBS) has been successful in a limited number of disorders; DBS typically targets one or two brain areas with single contacts on relatively large electrodes, allowing for only coarse modulation of circuit function. Because of the dysfunction in distributed neural circuits - each requiring fine, tailored modulation - that characterizes most neuropsychiatric disorders, this approach holds limited promise. To develop the next generation of neuromodulation therapies, we will have to achieve fine-grained, closed-loop control over multiple neural circuits. Recent work has demonstrated spatial and frequency selectivity using microstimulation with many small, closely-spaced contacts, mimicking endogenous neural dynamics. Using custom electrode design and stimulation parameters, it should be possible to achieve bidirectional control over behavioral outcomes, such as increasing or decreasing arousal during central thalamic stimulation. Here, we discuss one possible approach, which we term microscale multicircuit brain stimulation (MMBS). We discuss how machine learning leverages behavioral and neural data to find optimal stimulation parameters across multiple contacts, to drive the brain towards desired states associated with behavioral goals. We expound a mathematical framework for MMBS, where behavioral and neural responses adjust the model in real-time, allowing us to adjust stimulation in real-time. These technologies will be critical to the development of the next generation of neurostimulation therapies, which will allow us to treat problems like disorders of consciousness and cognition.

Automated 3D Design and Evaluation of RNA Nanostructures with RNAMake.

Despite growing interest in applying RNA's unique structural characteristics to solve diverse biotechnology and nanotechnology problems, there are few computational tools for targeted tertiary design. As a result, RNA 3D design is traditionally slow, resource-consuming, and dependent on expert modeling. In this chapter, we discuss our recently developed software package: RNAMake, a set of applications capable of designing RNA tertiary structures to solve various relevant nanotechnology problems and provide basic thermodynamic calculations for the generated designs. We provide in-depth examples and instructions for designing example RNA nanostructures such as minimal RNA sequences containing a single tertiary contact, generating RNAs that stabilize small-molecule ligands, and building tethers that link ribosomal subunits together. We also highlight the addition of a new Monte Carlo design algorithm and the ability to estimate the thermodynamic contribution of helical elements in RNA 3D structures.