Contact Points Research Articles

Construction of superhydrophobic composite coating on AZ31B Mg alloy for improved corrosion resistance and anti-wear property

In this study, the EP (epoxy)/L(P) (layered double hydroxides powder)-DTMS (dodecyl-trimethoxy-silane) superhydrophobic composite coating was prepared on AZ31B Magnesium (Mg) alloy surface by spin-coating and self-assembly methods. Mg-Al layered double hydroxides (LDH) powder with ion exchange ability, prepared by hydrothermal coprecipitation, was mixed with EP to construct rough surface and provide good adhesion between the coating and Mg alloy substrate. The introduction of DTMS could reduce the surface energy of coating and improve the compactness of rough surface. Due to the shielding effect of superhydrophobic surface and the ion exchange ability of LDH, it was difficult for corrosive ions (Cl-) to reach the substrate surface in 3.5 wt% NaCl solution. And the corrosion current density was decreased by 4 orders of magnitude. Because of the lubrication of DTMS and the layered structure of L(P), the composite coating had a good wear-reducing effect under the reciprocating point contact mode against with an AISI5200 steel ball. It provided a feasible idea for the construction of multifunctional superhydrophobic coatings on metal surface with self-cleaning, corrosion resistance and wear resistance, which will expand the industrial application fields of superhydrophobic coatings.

The Interplay between Airway Cilia and Coronavirus Infection, Implications for Prevention and Control of Airway Viral Infections.

Coronaviruses (CoVs) are a class of respiratory viruses with the potential to cause severe respiratory diseases by infecting cells of the upper respiratory tract, bronchial epithelium, and lung. The airway cilia are distributed on the surface of respiratory epithelial cells, forming the first point of contact between the host and the inhaled coronaviruses. The function of the airway cilia is to oscillate and sense, thereby defending against and removing pathogens to maintain the cleanliness and patency of the respiratory tract. Following infection of the respiratory tract, coronaviruses exploit the cilia to invade and replicate in epithelial cells while also damaging the cilia to facilitate the spread and exacerbation of respiratory diseases. It is therefore imperative to investigate the interactions between coronaviruses and respiratory cilia, as well as to elucidate the functional mechanism of respiratory cilia following coronavirus invasion, in order to develop effective strategies for the prevention and treatment of respiratory viral infections. This review commences with an overview of the fundamental characteristics of airway cilia, and then, based on the interplay between airway cilia and coronavirus infection, we propose that ciliary protection and restoration may represent potential therapeutic approaches in emerging and re-emerging coronavirus pandemics.

How GPs can help young people avoid future self-harm: a qualitative study.

Self-harm is a growing problem in young people. GPs are usually the first point of healthcare contact for young people aged 16-25 years, after self-harm. GPs can experience barriers to supporting young people and behaviour change theory can help to understand these, and the influences on, GP behaviour. To explore the capabilities, opportunities, and motivations (COM-B model of behaviour) of GPs, and their perceived training needs, to help young people aged 16-25 years avoid future self-harm. This was a qualitative study of GPs in England. Semi-structured interviews were conducted with NHS GPs who were purposively sampled. Interviews occurred in 2021. Data were analysed using reflexive thematic analysis and mapped onto the COM-B model domains. The study's patient and public involvement group supported data analysis. Fifteen interviews were completed. Four themes were generated. GPs described mixed capabilities, with many feeling they had the physical and psychological skills to support young people to avoid future self-harm, but some felt doing so was emotionally tiring. GPs identified opportunities to better support young people, such as use of electronic consultation tools, but cited lack of time as a concern. GPs reported motivation to help young people, but this can be influenced by their workload. Unmet training needs around communication, knowledge, and optimising safety were identified. GPs are supported by their practice teams to support young people after self-harm, but a lack of time hinders opportunities to do so. Future effective GP-led interventions may improve GP motivation to support young people after self-harm.

Ultrasound-Guided Polypectomy: Evaluation of a Novel Technique to Remove Endometrial Polyps in the Office.

To present a novel technique for office resection of pedunculated endometrial polyps under ultrasound guidance. A prospective trial was conducted at an academic center where women with abnormal uterine bleeding (AUB) who were diagnosed an endometrial polyp following saline infusion sonogram (SIS), were offered polyp removal under ultrasound guidance using a universal grasping forceps (2.5 mm × 25 cm). The primary outcome was to evaluate the feasibility of this technique for complete removal of the polyp. The secondary outcomes were to evaluate the patients' pain score, satisfaction score using visual analogue score (VAS), and efficacy of the technique in alleviating symptoms in patients with AUB due to polyps. Thirty patients participated, with a mean age of 54.8 ± 11 years. Average polyp volume was 1.87 cm3 and mean duration for polypectomy was 11 minutes 31 seconds. The median pain score immediately post-procedure was 5 (0-9). We were unable to complete the procedure in two patients due to patient discomfort and poor visualization. Complete removal of polyp was ensured by checking for a thin endometrial echo at the end of the procedure and by performing SIS at 3-months post-procedure. Of the 22 patients who returned for follow-up, 19 (86.36%) showed no evidence of polyp on SIS and all reported resolution of AUB symptoms. The median satisfaction score at the follow-up was 10/10. Adequate pathology samples were obtained from all cases, diagnosing malignancy in one and endometrial hyperplasia in one patient. This technique offers safe and effective removal of pedunculated endometrial polyps in an office setting, avoiding the need for general anesthesia. It can be offered as a therapeutic option at the initial point of contact, providing symptom relief and tissue diagnosis while reducing costs and patient visits.

Full-field stress-strain analysis of octagonal shape PMMA using reflection photoelasticity

This research involves stress-strain analysis in poly(methyl methacrylate) (PMMA) octagonal shape compressed by hydraulic system. The observation of uniaxially stressed samples was carried out using reflection photoelasticity technique. The results of fringe order number and principal stress angle were used to determine stress and strain distribution in the samples by shear difference method. It was found that high stress-strain region was close to the contact point where compressive force was applied but it was zero at the edge of the samples. The area of high strain region increased as the magnitude of force was increased but it decreased as the dimension of octagonal shape was increased.

Transnational Human Rights Violations: Addressing the Evolution of Globalized Repression through National Human Rights Institutions

Abstract Transnational Human Rights Violations (THRV) are infringements of individual rights that originate outside the jurisdiction in which they take effect. Ranging from violent and criminal forms of transnational repression through to coercion against targets’ family members abroad, digital surveillance, and legal intimidation, THRVs today generate widespread and systemic constraints on the exercise of human rights in jurisdictions around the world. At present, however, targets of THRVs typically find few avenues through which to raise complaints, receive assistance or pursue redress. This article proposes a new domestic institutional mechanism to directly address this situation. It first examines the mutually reinforcing, additive effects of transnational surveillance, coercion and censorship in the digital era. Next, it identifies relevant human rights standards showing state responsibilities to monitor and counter THRVs within their jurisdiction, and the growing recognition of additive, systemic effects of THRVs on broad populations. The third section examines policy responses in the United States, Australia, United Kingdom, and international organizations, noting that none has adequately addressed the contemporary nature and scope of THRVs as international standards require. The final section argues that to meet their obligations, states should establish Transnational Rights Protection Offices (TRPOs) to provide a clear contact point for targets to raise complaints and receive support; monitor and report on the situation of THRVs taking effect within the state’s jurisdiction; advise and inform government departments on THRV issues; and develop evidence-based policy recommendations. We conclude by laying out the rationale for its institutional status within National Human Rights Institutions (NHRIs).

The electron resistance of a single skyrmion within ballistic approach

An alternative way of skyrmion quasi-particle detection is simulated at low voltage bias. The point contact (PC), attached to the strip with a Néel-type skyrmion, can detect it with a higher efficiency than a magnetic tunnel junction. The method is based on detecting the skyrmion via the ballistic magnetoresistance ratio (BRR). PC's resistance with skyrmion significantly differs from the one without it. BRR is estimated in the framework of the point contact model for two directions of spin-polarized current: perpendicular to the transport direction (case 1) and along one (case 2). Skyrmion's size is assumed to be around 3.6 nm in diameter—smaller, or comparable, to the mean free path of electrons, allowing it to utilize the ballistic transport approach. As a result, resistance values for the considered Néel type skyrmion within the related size are estimated as 157 Ω for case 1 and 452.2 Ω for case 2 with optimistic BRR 101.3% and 291.7%, respectively. BRR for case 2 is higher due to the spin-filtering effect. The method also has the potential to detect the skyrmion type, or other magnetic nano structures such as bimeron, domain wall (DW), etc.

Hybrid Sensor Fusion Mixed with Reinforcement Learning in Autonomous Dual-Arm Lifting Tasks Performed by Humanoid Robots

Humanoid robots often struggle with tasks such as lifting objects due to the complexity involved in identifying contact points, applying the correct force, and tracking task progress. We propose an integrated solution that leverages the dual-arm capability of humanoids and utilizes sensor fusion from vision and force sensors. Our system employs a computer vision algorithm to detect and characterize object properties (shape, size, position, orientation) and differentiate between parallel and non-parallel bi-manipulation tasks. The controller then identifies optimal contact points for the end effectors, generating trajectories fed into a closed-loop controller using force feedback. For parallel bi-manipulation, momentum cancellation is achieved through sensor fusion. For non-parallel surfaces, a reinforcement learning algorithm determines the appropriate lifting force to prevent slippage using only two contact points. Experimental validation on a real humanoid platform demonstrates the effectiveness of our approach in autonomously lifting objects, regardless of contact surface configuration. This advancement significantly enhances the reliability and versatility of humanoid robots in performing complex manipulation tasks, contributing to their practical deployment in human-oriented environments.

Empowering Particle Jamming Soft Gripper with Tactility via Stretchable Optoelectronic Sensing Skin

Particle‐jamming soft grippers demonstrate notable shape adaptability and adjustable stiffness, which improve their grasping efficiency. However, integrating tactile sensing into these grippers presents challenges due to the specific properties of the particle jamming mechanism. This study introduces a parallel particle jamming soft gripper equipped with tactile sensing capabilities. The gripper consists of two tactile sensing particle jamming pads (TSPJPs) that are integrated with flexible optoelectronic skins. These skins are made of silicone rubber membranes and are embedded with a 3 × 3 array of stretchable optical waveguide arrays (SOWAs). Testing indicates that incorporating these sensors enhances the gripper's tactile sensing capabilities, with minimal impact on its particle jamming‐based grasping function. A single TSPJP can accurately detect various contact points and estimate the contract forces. The proposed soft gripper can reliably grasp a wide range of objects, varying in shape, hardness, and weight, and it provides detailed tactile feedback on contact locations and the intensity of the grasping through the SOWA sensor. It can precisely distinguish between different grasping postures using a light gradient boosting machine (LightGBM) learning model. Furthermore, it can effectively detect the slippage of grasped objects, facilitating accurate closed‐loop control for secure manipulation.

Tribological Characteristics of Fibrous Polyphthalamide-Based Composites.

The aim of this study was to investigate the tribological characteristics of commercially available high-strength polyphthalamide-based composites with great contents (30-50 wt.%) of both carbon and glass fibers in point and linear contacts against metal and ceramic counterfaces under dry friction and oil-lubricated conditions at various loads and sliding speeds. The lengths of both types of fibers were varied simultaneously with their contents while samples were fabricated from granules by injection molding. When loading PPA with 30 wt.% SCFs at an aspect ratio (AR) of 200, the ultimate tensile strength and the elastic modulus increased up to 142.7 ± 12.5 MPa and 12.9 ± 0.6 GPa, respectively. In the composites with the higher contents of reinforcing fibers PPA/40CCF and AR~1000, the ultimate tensile strength and the elastic modulus were 240 ± 3 MPa and 33.7 ± 1.9 GPa, respectively. Under the applied test conditions, a composite reinforced with 40 wt.% carbon fibers up to 100 μm long at an aspect ratio of ~1000 possessed the best both mechanical properties and tribological characteristics. One of the reasons that should be considered for improving the tribological characteristics of the composite is the fatigue wear mechanism, which is facilitated by the high filling degree, the strong interfacial adhesion, and the great aspect ratio for fibers. Under the oil-lubricated conditions, both friction coefficients and wear rates decreased, so such friction units could be implemented whenever possible. The reported data can be used as practical recommendations for applying fibrous polyphthalamide-based composites as friction unit components.

(Invited) Point-of-Care Biomembrane-Based Electronic Sensors

The development of medical devices that comply with the soft mechanics of biological systems at different length and complexity levels is highly desirable. With the emergence of conducting polymers exciting directions opened up in bioelectronics research, bridging the gap between traditional electronics and biology. With the ultimate goal of fully integrated devices, organic bioelectronic technologies have been heavily explored the past decade resulting in novel materials/device configurations. Multiplexing capability, ability to adopt to complex performance requirements in biological fluids, sensitivity, stability, literal flexibility and compatibility with large-area processes are only some of the merits of this technology for biomedical applications. A recent example of a bio-integrated electronic device, the BiOET, is based on polymeric semiconductor technology and is fabricated using nano/micro-fabrication methods in conjunction with synthetic biology approaches to incorporate hierarchically organized biological models of the cell membrane. Despite their significance, cell membranes are still an underexplored target for studying the mechanisms of diseases or drug therapies. Cell-free commercially available technologies for cell membrane studies have been limited to synthetic membranes that lack the inherent complexity found in the membrane of the cell. In this talk I will describe a method to create native cell membranes, using vesicles derived from live cells, on top of conducting polymer- based microfabricated electrodes and transistors. The activity of transmembrane proteins in response to different stimuli can be electrically monitored, offering a direct means to characterize drug toxicity or potency at the critical first contact point: membrane interaction.

(Invited) Thermo-Electrochemical Stability of Solid-State Batteries

Solid-state batteries (SSBs) are promising due to higher energy density and improved safety. While interface instability due to electrochemical-mechanics interaction, transport and morphological dynamics at solid-solid interfaces has been identified as a critical determinant of failure modes, the role of thermo-electrochemical effect is still elusive. A wide range of factors, such as, high reactivity of lithium, propensity for hotspot formation (e.g., at solid/solid point contacts), and cathode instability may affect thermo-electrochemical signature of solid-state architectures. In addition, spatio-temporal evolution of thermal and reaction heterogeneities and the occurrence of failure mechanisms such as lithium filament growth can be critical. In this presentation, the important role of internal thermal signature and mechanistic origin of thermo-electrochemical instability in solid-state battery architectures will be discussed.

Communicating and categorising ‘kidnap’ incidents in UK police emergency calls: a conversation analytic study

ABSTRACT This study of police emergency calls in the UK addresses the interactional work conducted when dealing with reports of kidnap. In the UK, kidnap is classed as a type of ‘crime-in-action’, known to be complex to categorise and code for the appropriate police response. Using the qualitative method of ‘conversation analysis’, we address this complexity through analysing a dataset of anonymised emergency calls which are, at some point during the call or subsequent police investigation, categorised as ‘kidnap’. Analysing the calls, their categorisations and the accompanying incident logs, we aim to understand the difficulties that can arise in identifying this type of high-stakes incident at the first point of police contact. We find callers encode differing levels of ‘entitlement’ in requests for police assistance, with potential effects on call-handlers’ decisions about kidnap categorisations. We also observe interactional difficulties in establishing information about the incident, either through the caller’s displayed lack of knowledge or certainty, difficulty in producing turns or sometimes resistance to providing further information. These features may render the call-handler’s task of categorising incidents as ‘kidnap’ more challenging. Our identification of these communicative patterns has potential benefits for call-handlers’ practices in the police control room, providing an evidence-base from real-life talk for training. The findings also have implications at an institutional level, as they shed light on the negotiations that underly ‘categorisation’ work in policing, where there may sometimes only be a tacit understanding of how crime categories are decided during initial reports from the public.

Barriers and Facilitators to the Use of Wearable Robots as Assistive Devices: Qualitative Study With Older Adults and Physiotherapists.

Light wearable robots have the potential to assist older adults with mobility impairments in daily life by compensating for age-related decline in lower extremity strength. Physiotherapists may be the first point of contact for older adults with these devices. The aims of this study were to explore views of older adults and physiotherapists on wearable robots as assistive devices for daily living and to identify the barriers and facilitators to their use. Six older adults (aged 72-88 years) tested a wearable robot (Myosuit) and participated in semistructured interviews. A focus group with 6 physiotherapists who had a minimum of 5 years of professional experience and specialized in geriatrics was conducted. Data were analyzed using thematic qualitative text analysis. Older adults perceived benefits and had positive use experiences, yet many saw no need to use the technology for themselves. Main barriers and facilitators to its use were the perception of usefulness, attitudes toward technology, ease of use, and environmental factors such as the support received. Physiotherapists named costs, reimbursement schemes, and complexity of the technology as limiting factors. A light wearable robot-the Myosuit-was found to be acceptable to study participants as an assistive device. Although characteristics of the technology are important, the use and acceptance by older adults heavily depend on perceived usefulness and need.

Entrance process and interface distribution of nanoparticles in point contact

Nanoparticles have proven to be effective in reducing friction and wear in tribological systems. Previous research mainly focused on the behavior of nanoparticles within the contact region, often overlooking the dynamics of particle's ingress into the interface. This study introduces an innovative model to elucidate the entry process of particles in point contact, grounded in mechanical analysis. The model is employed to investigate the distribution and load-bearing capacity of nanoparticles within the interface, considering variables such as velocity, applied load, particle concentration, particle size, and friction coefficient. Relative ball-on-disk experiments were conducted to verify the model’s prediction, with particular attention to the elemental distribution of particles along the wear tracks. Both theoretical and experimental results indicate that the distribution of particles shifts from covering the whole contact interface to concentrating at the edge in the movement direction as the external load increases and the velocity decreases. Additionally, while the spatial distribution of particles remains constant, the particle concentration within the interface significantly increases with higher nanoparticle concentrations. The enhanced tribological performance of nanofluid is attributed to a greater number of particles entering the contact region.

Ad Hoc Modeling of Rate-Dependent Adhesion in Indentation Relaxation Testing.

The phenomenon of rate-dependent adhesion has long been recognized as an intricate problem, and the so-far-developed physics and mechanics-based approaches resulted in analytical relations between the implicit form between the work of adhesion and the contact front velocity which are difficult to implement in practice. To address this issue in the framework of spherical indentation, the adhesion relaxation test in a nominal point contact is introduced to estimate the rate-dependent adhesion. Based on a stretched exponent approximation for the contact radius evolution with time, a relatively simple four-parameter model is proposed for the functional relation between the work of adhesion and the contact front velocity, and its fitting performance is compared to that of the known Greenwood-Johnson and Persson-Brener models.

Attitudes and responses of Victorian paediatric intensive care doctors to the detection and reporting of child maltreatment.

To determine the attitudes and responses of Victorian paediatric intensive care doctors to the detection and reporting of child maltreatment. A prospective study conducted in a 30-bed paediatric intensive care unit of a university teaching hospital using data collected from a questionnaire completed by paediatric intensive care consultants and registrars. The questionnaire covered the following domains - doctors' knowledge of Victorian mandatory reporting legislation, doctors' history of reporting and doctors' current role in the detection and reporting of child maltreatment. The questionnaire was completed by 37 doctors. All but one doctor considered their role in the detection and reporting of all six forms of maltreatment (physical abuse, sexual abuse, emotional abuse, neglect, exposure to domestic violence and grooming to facilitate later sexual activity with a child) very important or somewhat important. Thirty-two percent of doctors did not feel adequately trained to detect child maltreatment while 51% did not feel adequately trained to report maltreatment. If a doctor wanted to make a report to Child Protection about the physical or sexual abuse of a child, only one would likely make Child Protection their first point of contact. Paediatric intensive care doctors show a strong intent to detect and report child maltreatment across a broad range of maltreatment types. Doctors are likely to contact one or more members of a child's care team and/or one or more relevant hospital/community services before making a report to Child Protection about the physical or sexual abuse of a child. Opportunities exist for the further education of doctors in regards to the detection and reporting of child maltreatment.

The kpc-1 3'UTR facilitates dendritic transport and translation efficiency of mRNAs for dendrite arborization of a mechanosensory neuron important for male courtship.

A recently reported Schizophrenia-associated genetic variant in the 3'UTR of the human furin gene, a homolog of C. elegans kpc-1, highlights an important role of the furin 3'UTR in neuronal development. We isolate three kpc-1 mutants that display abnormal dendrite arborization in PVD neurons and defective male mating behaviors. We show that the kpc-1 3'UTR participates in dendrite branching and self-avoidance. The kpc-1 3'UTR facilitates mRNA localization to branching points and contact points between sibling dendrites and promotes translation efficiency. A predicted secondary structural motif in the kpc-1 3'UTR is required for dendrite self-avoidance. Animals with over-expression of DMA-1, a PVD dendrite receptor, exhibit similar dendrite branching and self-avoidance defects that are suppressed with kpc-1 over-expression. Our results support a model in which KPC-1 proteins are synthesized at branching points and contact points to locally down-regulate DMA-1 receptors to promote dendrite branching and self-avoidance of a mechanosensory neuron important for male courtship.

Asymmetric mate preference and reproductive interference mediate climate-induced changes in mate availability in a small mammal hybrid zone.

Range expansion and contraction are among the most common biotic responses to changing environmental conditions, yet much is to be learned about the mechanisms that underlie range-edge population dynamics, especially when those areas are points of secondary contact between closely related species. Here, we present field-measured parentage data that document the reproductive outcomes of changes in mate availability at a secondary contact zone between two species of woodrat in the genus Neotoma. Changes in mate availability resulted from drought-driven differential survival between the species and their hybrids. As the availability of conspecific mates declined, rates of hybridization increased, leading to the accumulation of admixed individuals in the zone of contact. Patterns of reproductive success in the wild appear to be the result of a combination of both pre-mating isolation and post-zygotic selection resulting from genomic incompatibilities between the parental lineages. Evidence of asymmetric mate preference between the parental lineages came from both skewed reproductive output in the field and laboratory preference trials. Moreover, partial genomic incompatibility was evident from the near-zero reproductive success of F1 males and because nearly all surviving hybrids had one pure parent. Nonetheless, high reproductive success of F1 females and backcrossing in both parental directions allow for introgression between the parental species. These findings reveal how climate change may alter evolutionary outcomes for species at the edge of their ranges through an interplay of behavioral, demographic, and genetic mechanisms.

Can you know before you go? Information about disability accommodations on UShospital websites.

People with disability (PWD) face challenges accessing healthcare. Websites are a public-facing resource that can help PWD determine if a hospital can accommodate their needs, yet few studies have described whether hospital websites contain adequate accommodation information. To characterize the extent to which information about disability accommodations is available on UShospital websites. We manually reviewed hospital websites using a structured extraction form. We used the Centers for Medicare and Medicaid Services'Hospital General Information Data set to identify a stratified random sample of 600 nonspecialty hospitals in the United States. We excluded hospitals that shared a website with a previously reviewed hospital for a final sample of 445. We recorded(1) content about specific disability accommodations (in 11 predetermined categories); (2) descriptions of hospital policy mentioning disability; and (3) the point of contact to obtain more information about accommodations. About two-thirds (65.6%) of sampled hospitals were acute care hospitals (vs34.4% critical access); 53.5% had 26-299 beds. Overall, 73.7% websites had information about accommodations; of these, 36.3% had information solely within hospital policies. Of the 47.0% websites with accommodation information beyond hospital policies, the mean number of accommodations listed (excluding policy statements) was 2.37 (of 11 possible). Hospitals with 300+ beds had higher odds of listing any nonpolicy accommodations than those with 1-26 beds (odds ratio = 2.768, p = .02). Less than half (40.5%) hospitals listed a contact person. Information about disability accommodations is sparse on hospital websites. Comprehensive and actionable communication about accommodations is needed to better protect PWD's rights to accessible healthcare.