搜索结果：Pads

The effect of polishing pads is generally incorporated as a coefficient in the conventional Preston equation and its modified forms during the past century, and macroscopic stress distribution and microscopic motion states are discussed separately. To solve this challenge, we propose a novel cross-scale model using a unified physical framework integrating the macroscopic and microscopic states. The proposed model decomposes the effect of polishing pads into stress transfer and abrasive constraint factors. It connects microstructure, stress transfer, abrasive constraint and material removal in sequence and establishes a relationship between the microstructure of pads and the evolution of a polished surface. Finite element simulations show that the maxima of von Mises stresses on fused silica are 0.171, 0.749 and 0.446 MPa for non-woven, polyurethane, and asphalt pads, respectively, corresponding to the support of discrete fibers, local stress concentration and continuous transfer of stress. Furthermore, single-abrasive scratching confirms that the maxima of equivalent stress exerted by the associated three pads are 2.059, 4.701 and 7.771 MPa, respectively, relevant to weak, unstable and strong constraints of abrasives. Polishing experiments were performed on fused silica with ceria slurry. They demonstrate that the peak-to-valley value obtained using an asphalt pad decreases from 385.976 to 115.237 nm and the attenuation of power spectral density is 88%. The surface roughness Sa achieved using a non-woven pad is reduced from 2.145 to 0.721 nm. The predictions of the proposed model are in good agreement with the simulation and experimental results. Our outcomes provide new insights into achieving error convergence of full bands on polished surfaces using different polishing pads.

Canine protothecosis is an uncommon opportunistic infection, most frequently reported in warm, humid climates. In dogs, it typically presents as disseminated disease following primary colonic involvement and carries a poor prognosis for clinical cure. No standardised treatment protocol exists in veterinary medicine. Regimens that maintain an acceptable quality of life often incorporate posaconazole, while amphotericin B may be used with curative intent in selected cases. We report the first documented case of localised cutaneous protothecosis due to Prototheca wickerhamii in a dog from Tasmania, Australia, together with its successful management. A 2-year-old neutered male Chihuahua cross presented with painful swelling and ulceration of the metacarpal and metatarsal pads, resulting in marked lameness. Diagnosis was established by cytology, histopathology, culture and MALDI-ToF mass spectrometry on samples from affected pads. Three sequential treatment protocols were trialled: (i) modified pulsed itraconazole therapy, (ii) oral posaconazole and (iii) intralesional amphotericin B deoxycholate. Itraconazole was ineffective. Posaconazole led to the resolution of clinical signs, although ongoing therapy was required, and relapse occurred after cessation of therapy. Subsequent treatment with intralesional amphotericin B achieved sustained clinical remission, consistent with sustained clinical remission and possible cure. This case expands the recognised geographic and clinical spectrum of canine protothecosis, documenting infection in a temperate region and in a localised cutaneous form. It highlights the importance of considering protothecosis in atypical dermatological presentations and supports the use of posaconazole for disease control and amphotericin B, specifically intralesional administration, for definitive therapy in clinical veterinary practice settings.

Currently, most design solutions are disc brake systems, in which, during braking, the rotating disc, along with the wheel, rubs against stationary brake pads, converting kinetic energy into thermal energy released into the atmosphere. Brake pads are made of composite materials. One of the key components is copper. Its presence is crucial and plays a crucial role in friction materials. In this work, an attempt was made to replace copper, which is unfortunately harmful to both the environment and humans, with aluminum powder and polytetrafluoroethylene powder. Samples of the proposed prototype friction materials were manufactured, and their thermal and tribological properties were determined (research described in the previous work). Knowledge of the materials' properties allowed for simulation studies. Calculations were prepared for three different scenarios. The results showed that the heating process using the proposed materials during braking is very similar to that of materials with a conventional composition. Of the materials tested, composition where copper was replaced by polytetrafluoroethylene and aluminum in a 4:1 ratio gave the most promising results. In tests, this material had the lowest maximum brake pad temperature values, which contributes to a reduced risk of fading. Also, by "pushing" thermal energy into the brake disc, it contributes to the fastest dissipation of this energy. This suggests that the materials can be used in real-world braking systems.

Thinning of fat pads may elevate the risk of developing plantar foot ulcers potentially resulting in lower-extremity amputations. Evaluating whether fat pad thickness is associated with plantar foot ulceration could aid in early risk detection. This study therefore aims to compare fat pad thickness between type 2 diabetes mellitus (T2DM) patients with and without plantar foot ulcers using MRI. This retrospective cross-sectional study included patients diagnosed with T2DM of whom a nonweight bearing MRI of the ankle or foot was available. The thickness of the calcaneal fat pad was measured in the sagittal plane, measuring perpendicularly from the lowest cortex of the calcaneal bone to and including the skin. Calcaneal fat pad thickness was compared between T2DM patients with and without plantar foot ulceration. In total, 42 patients were included of which 16 in the T2DM group with plantar foot ulceration. The calcaneal fat pad was significantly thinner in T2DM patients with plantar foot ulceration compared to those without plantar foot ulceration (15.7 ± 3.2 mm vs. 18.6 ± 2.8 mm, p = 0.004). This study established an initial association between fat pad thickness and plantar foot ulceration in T2DM patients. Our findings suggest that a reduction in calcaneal fat pad thickness may decrease the shock-absorbing ability of the plantar fat pads, making the underlying tissue more vulnerable to injury, increasing the risk of developing plantar foot ulcers. The initial association between fat pad thickness and foot ulceration should be further explored to discover its potential in clinical practice.

Bronchiectasis is a chronic inflammatory lung disease characterized by permanent airway dilation, mucus production, recurrent infections, and progressive structural injury. Inborn errors of immunity (IEI), particularly predominantly antibody deficiencies (PADs), are important and potentially underrecognized causes of non-cystic fibrosis bronchiectasis (NCFB). Antibody deficiency increases susceptibility to bacterial infection, but the observation that bronchiectasis develops in only a subset of patients with PADs, and may develop despite immunoglobulin replacement therapy (IGRT), indicates that serum antibody measurements alone do not fully define the airway risk. Bronchiectasis in IEI likely reflects the interaction of impaired systemic humoral immunity impacting mucosal immune defenses, altered IgG transport or catabolism, B cell dysregulation, T cell and innate immune dysfunction, autoimmunity, environmental exposures, comorbid lung disease, and chronic airway infection. In this review, we summarize reported frequencies of NCFB among selected IEIs with antibody deficiency, discuss the limitations of IgG subclass and serum-based antibody testing as predictors of airway disease, and review evidence supporting higher individualized IGRT dosing in patients with antibody deficiency and bronchiectasis to achieve therapeutic IgG levels. We also propose a practical clinical framework for evaluating immune defects in bronchiectasis and for longitudinal pulmonary screening in patients with IEIs at increased risk of bronchiectasis.

Phenolic acid decarboxylases (PADs) convert bio-based hydroxycinnamic acids into valuable hydroxystyrene monomers under mild reaction conditions. These compounds are in high demand in polymer production, cosmetics, and flavoring. Especially 4-vinyl syringol, the decarboxylation product from sinapic acid, generates polymers with similar thermal stability and higher glass transition temperatures than vinyl guaiacol, the decarboxylation product from ferulic acid. However, natural PAD enzymes typically show slow turnover with sinapic acid. In addition, establishing a viable industrial process requires enzymes operating under elevated temperatures. To tackle these issues, we assessed five thermostable ancestral PADs towards their activity and stability for the conversion of ferulic acid and sinapic acid at different temperatures. A combinatorial active site library was prepared for the most thermostable ancestor. We expanded the substrate scope of a selected PAD ancestor to include sinapic acid through directed mutagenesis. A trade-off between ferulic-/caffeic acid and sinapic acid was observed and investigated via molecular dynamics simulations. The most stable ancestor was identified with a half-life of 3.65 days, analyzed at 50°C. We found the Ile29Ser-Leu80Ser-Ile93Ala triple mutation (SSA) to effectively expand the substrate scope with an 11-fold increase in catalytic efficiency for sinapic acid, and a half-life of 1.12 days at 50°C, being approximately 1.6-fold higher than the frequently used PAD from Bacillus subtilis.

To assess the cleaning potential of different powder abrasive devices (PADs) employing glycine powder in different peri-implant defect models, simulating the non-surgical and surgical approach. 120 implants were stained with insoluble ink and mounted in models with circular steep and horizontal defects with and without simulated mucosa. Debridement was performed with three different commercially available PADs (1-3) for 120&#xa0;s, either with a hand piece for the surgical or the nozzle for the non-surgical approach. Each treatment mode was performed on ten implants, respectively. Photos from each implant were taken under UV-A light activation and residually stained areas planimetrically assessed. Cleaning was tested for intergroup differences by two-way ANOVA with Bonferroni correction. Potential changes in the micro-morphology were investigated by scanning electron microscopy. Taken all experiments together, device I performed significantly better than the others (p&#x2009;<&#x2009;0.05). For the non-surgical approach, no significant overall difference was found. Horizontal defects were cleaned better than steep defects in all treatment-groups (p&#x2009;<&#x2009;0.001). For the surgical approach, there was a significant overall difference between group I and III (p&#x2009;=&#x2009;0.031). For both defect types, significant inter-group differences were found except for group II and III in the horizontal defect (p&#x2009;<&#x2009;0.05). No configuration showed complete cleaning. Apically facing thread surfaces were found to be the most difficult to clean. (1) Different devices showed considerably different cleaning performances. Generally, stand-alone devices tended to perform better than powder chambers mounted on a handpiece. (2) Throughout the settings, steep defects are more difficult to clean.

Little is known about female sex worker (FSW) experiences with menstruation and its impact on their economic livelihood and health. To support a future intervention aimed at improving menstrual hygiene management (MHM) for FSW, this study sought to explore FSW's views of MHM, its impact on work, and related practices during client engagement. This qualitative study conducted seven focus group discussions among 57 FSWs in Kisumu, western Kenya, between June and September 2023. Semi-structured guides assessed current MHM practices, the impact of menstruation on work and livelihood, and clients' perceptions of sex during menses. The data were analysed using thematic analysis. Outside of sex work, FSWs primarily reported using disposable sanitary pads, with tampons, reusable pads, cloths, cotton wool and tissue also reported as methods used to absorb menstrual flow. Many FSWs described continuing sex work during menstruation out of financial necessity. Needing to hide menstrual blood flow when engaging in sex work was customary and women resorted to unsafe practices, including intravaginal cleansing or inserting cotton or tissue high into the vagina to stem bleeding. Most FSWs spoke of losing income during their menses from stopping work entirely or reducing the number of clients seen. Women reported a range of client attitudes towards sex during menstruation, from indifference to disgust, with most reporting negative views. FSWs discussed that clients frequently refused services if they became aware of menstruation and that non-payment or physical abuse from clients could occur upon discovering menstruation. The use of harmful practices to conceal menstrual blood during sex work underscores a critical need for safer menstrual management solutions for this population that can be used discreetly and comfortably during sex, such as menstrual discs that can be worn during sex. Negative perceptions of menstruation contribute to increased financial instability in this population.Clinical Trial Registration: Clinicaltrials.gov NCT05666778; Pan African Clinical Trials Registry 202305912778108.

Lemmel syndrome is a rare and misdiagnosed cause of obstructive jaundice due to a periampullary duodenal diverticulum (PAD) in the absence of choledocholithiasis or a tumor. PADs are extraluminal outpouchings of duodenal mucosa that develop within a radius of 2-3 cm from the ampulla of Vater. They are largely asymptomatic, but rarely they can cause acute abdominal pain and obstructive jaundice due to the extrinsic compression of the common bile duct or pancreatic duct. PADs are mostly asymptomatic, but complications can occur, such as hemorrhage, perforation, diverticulitis, pancreatitis, choledocholithiasis, cholangitis, jaundice, or intestinal obstruction. Treatment workup depends on the clinical presentation. The authors present the clinical case of an 84-year-old woman who presented to the emergency department with jaundice, refusal to feed, vomiting, and prostration with a two-day&#xa0;duration. On physical examination, jaundice and tenderness in the upper quadrants were observed.&#xa0;Blood tests revealed anemia, leukocytosis with neutrophilia, and elevated aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase, and gamma-glutamyl transferase. Abdominal computed tomography&#xa0;showed ectasia of the intra-hepatic bile ducts and main bile duct, compressed extrinsically by a PAD. Due to the patient's previous functional status, conservative management was decided.

BackgroundPeriod product insecurity is an emerging form of material hardship with significant implications for mental health. Previous research has shown that financial challenges related to accessing material basic needs hygiene products can increase stress and anxiety.ObjectivesThis study aims to examine the relationship between frequencies of period product insecurity, parenting stress, and mental health outcomes in caregivers with young children.DesignThe study uses cross-sectional survey data from participants (N=541) who menstruated in the past year and were caregivers of children under age four. Data were collected during completion of an online survey from March - April 2024.MethodParticipants reported experiences with period product insecurity and completed standardized measures of anxiety and depression (GAD-2 and PHQ-2). Logistic regression models, adjusting for sociodemographic factors, estimated the association between period product insecurity frequency, parenting stress, and mental health outcomes.ResultsAmong participants, 39.5% (n=214) endorsed period product insecurity at least once in the past year. The majority of caregivers with young children who experienced period product insecurity monthly reported symptoms of Generalized Anxiety Disorder (68.4%, n=156) or major depressive disorder (72.3%, n=112). Fewer caregivers who did not experience period product insecurity reported symptoms (Generalized Anxiety Disorder 27.0%, n=87; major depressive disorder 27.1%, n=87). More than half of all caregivers "completely agree" or "agree" that they felt stressed or anxious about the responsibilities that come with parenting/caretaking (57.7%, n=308). Monthly experiences of period product insecurity, and stress about parenting responsibilities, increased risk of symptoms of anxiety and depression compared with no period product insecurity (p<.001).ConclusionFuture research is needed to strengthen the evidence base to better understand the causal pathways between period product insecurity and caregiver mental health. In the meantime, interventions and policy measures could be explored to integrate both period product distribution and parenting supports within broader caregiver support systems. Why we did this study: Being a parent can be very stressful, so can worrying about how to pay for basic essentials like period products (including pads and tampons). Not being able to afford period products is called period product insecurity or period poverty. Parents&#x2019; mental health can impact how they parent their children. What we wanted to learn: We wanted to understand if there is a connection between not being able to afford period products, feeling stressed about parenting responsibilities, and the mental health of caregivers with young children. What we did: From March 2024 to April 2024, 541 caregivers who had menstruated in the past year and lived with a child under age four completed an online survey. Survey questions asked whether participants had trouble affording period products like pads or tampons, how often that happened, whether they felt stressed about caregiving responsibilities, and whether they experienced symptoms of anxiety or depression. What we learned: 40% of caregivers said they had struggled to afford period products in the past year, and 29% said it happened every month. Caregivers who experienced period product insecurity monthly were much more likely to report parenting stress and symptoms of anxiety and depression, even after considering other factors like income and employment. Why is this important: Struggling to afford period products can contribute to serious mental health challenges for caregivers of young children. This can make it hard for caregivers to be the parents they want to be for their children. We need the people who make the laws for our states and country and decide how to spend the government&#x2019;s money to use policies and funding to make free period products available to caregivers with young children. This could help reduce stress, improve mental health, and support families raising young children.

The development and performance of self-lubricating Cu-Fe-based composites produced via powder metallurgy are examined as an advanced alternative to conventional Babbitt alloy for guide pad applications in high-speed circular saw systems. The proposed composite addresses the inherent limitations of Babbitt, particularly its low mechanical strength and poor wear resistance under high contact pressures, aiming to improve durability and operational reliability. A baseline Cu-5 vol.% Ni-coated graphite (NCG)-6 vol.% CaF&#x2082; composite was reinforced with incremental Fe additions (12-52 vol.%) to enhance mechanical strength while preserving favorable tribological properties. The composites were characterized through pin-on-disk and dry sand rubber wheel (DSRW) wear tests, complemented by mechanical evaluation (hardness and tensile testing) and detailed microstructural examination using SEM/EDS. The results demonstrate that increasing Fe content significantly improves hardness, yield strength, and wear resistance, with the composite containing 42 vol.% Fe achieving the optimal performance balance. This composition exhibited nearly a twofold increase in hardness and an approximately threefold increase in yield strength, along with a 94% reduction in sliding wear during pin-on-disk test and an 81% reduction in abrasive wear compared to Babbitt. These improvements are attributed to the enhanced load-bearing capacity of the Fe-reinforced matrix and the formation of a stable oxide-rich tribolayer that effectively limits direct surface interaction and suppresses material removal. In contrast, excessive Fe content (52 vol.%) led to brittle oxide formation and increased wear due to crack propagation and delamination, confirming the existence of a critical reinforcement threshold. Semi-industrial testing further validated the superior performance of the optimized Cu-Fe-based composite. Compared to Babbitt, the optimized composite demonstrated reduced power consumption and negligible material transfer to the saw blade, indicating improved tribological efficiency. Surface morphology analyses of the guide pads revealed that while Babbitt guide pad experienced severe material loss, the Cu-Fe-based composite maintained a smooth and coherent contact surface with minimal damage. Overall, the Cu-42 vol.%Fe-5 vol.%NCG-6 vol.%CaF2- composite emerges as a highly effective and durable replacement for Babbitt guide pads, offering superior wear resistance.

Alterations in periarticular lipid composition are implicated in musculoskeletal diseases, yet short-term reliability of MRI-based triglyceride composition mapping in the knee is not fully established. To evaluate 1-week repeatability of proton-density fat fraction (PDFF) and triglyceride fatty-acid composition-saturated (SFA), monounsaturated (MUFA), and polyunsaturated (PUFA)-in periarticular knee tissues. Prospective. Ten healthy adults (5 female, 5 male; age 32&#x2009;&#xb1;&#x2009;8&#x2009;years; BMI 23.5&#x2009;&#xb1;&#x2009;2.4&#x2009;kg/m2). 3T; 12-echo 3D spoiled gradient-echo acquisition for chemical shift-encoded fat quantification and a proton density-weighted SPACE sequence for segmentation (0.6&#x2009;mm isotropic). Participants underwent repeated MRI 1&#x2009;week apart. Femoral and tibial bone marrow, patella, Hoffa's fat pad, prefemoral fat pad, quadriceps fat pad, posterior fat pad, and subcutaneous adipose tissue were segmented and rigidly aligned. Voxelwise spectral fitting was used to estimate PDFF and fatty acid composition, including SFA, MUFA, and PUFA components. Repeatability metrics included bias, within-subject standard deviation (wSD), within-subject coefficient of variation (wCV%), coefficient of repeatability, and intraclass correlation coefficient (ICC). Paired t-tests assessed systematic differences (&#x3b1;&#x2009;=&#x2009;0.05); ICCs used a two-way random-effects, absolute-agreement model (ICC(2,1)). PDFF showed lowest variability across all regions (wCV: 1.5%-5.9%; ICC: 0.33-0.96). SFA demonstrated similar stability (wCV: 2.4%-12.6%; ICC: 0.19-0.87). MUFA exhibited anatomy-dependent reliability (wCV: 4.1%-21.1%; ICC: 0.17-0.97), with highest repeatability in subcutaneous adipose tissue (ICC: 0.97) and Hoffa's fat pad (ICC: 0.85). PUFA displayed the greatest variability (wCV: 3.6%-52.8%; ICC: 0.10-0.94), with the greatest instability in periarticular fat pads. No paired comparisons were significant (all p&#x2009;>&#x2009;0.05; range p&#x2009;=&#x2009;0.14-0.98). Regional ordering remained consistent across sessions. A 12-echo chemical shift-encoded MRI protocol provides repeatable PDFF and SFA measurements over 1&#x2009;week. MUFA reliability varies by tissue, while PUFA remains least stable. 2 (Prospective cohort). 2 (Reproducibility/feasibility evaluation). Fat tissues around the knee, including bone marrow and periarticular fat pads, are active biological tissues whose composition may change in joint diseases such as osteoarthritis. We tested whether a specialized MRI technique can reliably measure fat types in these tissues. Ten healthy adults were scanned twice, 1&#x2009;week apart, at 3Tesla. Total fat content and the proportions of saturated, monounsaturated, and polyunsaturated fats were measured in eight knee regions. Measurements were stable between sessions, especially for total fat content and saturated fats. This approach could support future studies tracking fat changes linked to joint disease.

Despite the cost, disposal issues, risk of infections and environmental burden, sanitary pads continue to be the most used method of menstrual hygiene among young women in India. Menstrual cups are a safer, cost-effective and environmentally friendly option, but acceptance is very low because of myths, cultural taboos and absence of organised education. There has been no randomised trial in Sikkim to assess a menstrual cup awareness and use promotion intervention. This study is designed to assess the effect of a Nurse-Led Menstrual Hygiene Management Package (NL-MHMP) on awareness, perception and sustained use of menstrual cups among university students. A randomised active wait list-controlled trial will be conducted among 140 undergraduate female students (18-25 years) using proportionate stratified sampling technique from government and private universities in Gangtok, Sikkim and simple randomisation will be used to allocate participants into intervention and wait list groups. The NL-MHMP includes a 15-minute teaching session, audiovisual demonstration, graphical hand-out, clarification session, and the distribution of two ISO-certified menstrual cups with digital follow-up for six menstrual cycles. The primary outcome is sustained adoption of menstrual cup use among sanitary pad users. Secondary outcomes include changes in awareness, attitude, acceptability, adaptability, misconceptions, satisfaction, and preference toward menstrual cups. This nurse-led, digitally supported intervention offers a structured and scalable approach to improving menstrual health literacy and promoting sustainable menstrual hygiene practices among young women in Sikkim. Findings may inform university-based health programs and contribute to evidence-based policy initiatives supporting eco-friendly menstrual products. The study is registered on 19/06/2025 in the Clinical Trial Registry India with trial ID: CTRI/2025/06/089117, prospectively registered.