Hypersensitive meta-crack strain sensor for real-time biomedical monitoring.

Real-time monitoring of infinitesimal deformations on complex morphologies is essential for precision biomechanical engineering. While flexible strain sensors facilitate real-time monitoring with shape-adaptive properties, their sensitivity is generally lower than spectroscopic imaging methods. Crack-based strain sensors achieve enhanced sensitivity with gauge factors (GFs) exceeding 30,000; however, such GFs are only attainable at large strains exceeding several percent and decline below 10 for strains under 10, rendering them inadequate for minute deformations.

Spongy Ag Foam for Soft and Stretchable Strain Gauges.

Strain gauges, particularly for wearable sensing applications, require a high degree of stretchability, softness, sensitivity, selectivity, and linearity. They must also steer clear of challenges such as mechanical and electrical hysteresis, overshoot behavior, and slow response/recovery times. However, current strain gauges face challenges in satisfying all of these requirements at once due to the inevitable trade-offs between these properties.

Rapid Self-Healing Hydrogel with Ultralow Electrical Hysteresis for Wearable Sensing.

Self-healing hydrogels are in high demand for wearable sensing applications due to their remarkable deformability, high ionic and electrical conductivity, self-adhesiveness to human skin, as well as resilience to both mechanical and electrical damage. However, these hydrogels face challenges such as delayed healing times and unavoidable electrical hysteresis, which limit their practical effectiveness. Here, we introduce a self-healing hydrogel that exhibits exceptionally rapid healing with a recovery time of less than 0.

Transparent Intracellular Sensing Platform with Si Needles for Simultaneous Live Imaging.

Vertically ordered Si needles are of particular interest for long-term intracellular recording owing to their capacity to infiltrate living cells with negligible damage and minimal toxicity. Such intracellular recordings could greatly benefit from simultaneous live cell imaging without disrupting their culture, contributing to an in-depth understanding of cellular function and activity. However, the use of standard live imaging techniques, such as inverted and confocal microscopy, is currently impeded by the opacity of Si wafers, typically employed for fabricating vertical Si needles.

Active site engineering of Zn-doped mesoporous ceria toward highly efficient organophosphorus hydrolase-mimicking nanozyme.

Hydrolase-mimicking nanozymes have received increasing attention in recent years, but the effective rational design and development of these materials has not been realized, as they are not at present considered a critical research target. Herein, we report that Zn-doped mesoporous ceria (Zn-m-ceria) engineered to have an abundance of two different active sites with different functions-one that allows both co-adsorption binding of organophosphate (OP) and water and another that serves as a general base-has significant organophosphorus hydrolase (OPH)-like catalytic activity. Specifically, Zn-m-ceria exhibits a catalytic efficiency over 75- and 25-fold higher than those of m-ceria and natural OPH, respectively.

Wearable Sensor Patch with Hydrogel Microneedles for In Situ Analysis of Interstitial Fluid.

Continuous real-time monitoring of biomarkers in interstitial fluid is essential for tracking metabolic changes and facilitating the early detection and management of chronic diseases such as diabetes. However, developing minimally invasive sensors for the in situ analysis of interstitial fluid and addressing signal delays remain a challenge. Here, we introduce a wearable sensor patch incorporating hydrogel microneedles for rapid, minimally invasive collection of interstitial fluid from the skin while simultaneously measuring biomarker levels in situ.

In Situ Spray Polymerization of Conductive Polymers for Personalized E-textiles.

E-textiles, also known as electronic textiles, seamlessly merge wearable technology with fabrics, offering comfort and unobtrusiveness and establishing a crucial role in health monitoring systems. In this field, the integration of custom sensor designs with conductive polymers into various fabric types, especially in large areas, has presented significant challenges. Here, we present an innovative additive patterning method that utilizes a dual-regime spray system, eliminating the need for masks and allowing for the programmable inscription of sensor arrays onto consumer textiles.

Rh-coordinated histidyl bolaamphiphile assembly: a catalyst for the isomerization of -stilbene and -alkene.

In this study, we present a colloidal assembly of histidyl bolaamphiphiles whose imidazoles coordinate with rhodium ions (HisC7[Rh]) to exhibit catalytic isomerization activity for -stilbene and -alkene molecules. The histidyl bolaamphiphiles self-assemble to form a soft scaffold that functions analogously to an apoenzyme. This scaffold exposes multiple histidyl imidazoles and carboxylates on its surface, to which rhodium ions bind, generating catalytically active sites.

Principles for Controlling the Shape Recovery and Degradation Behavior of Biodegradable Shape-Memory Polymers in Biomedical Applications.

Polymers with the shape memory effect possess tremendous potential for application in diverse fields, including aerospace, textiles, robotics, and biomedicine, because of their mechanical properties (softness and flexibility) and chemical tunability. Biodegradable shape memory polymers (BSMPs) have unique benefits of long-term biocompatibility and formation of zero-waste byproducts as the final degradable products are resorbed or absorbed via metabolism or enzyme digestion processes. In addition to their application toward the prevention of biofilm formation or internal tissue damage caused by permanent implant materials and the subsequent need for secondary surgery, which causes secondary infections and complications, BSMPs have been highlighted for minimally invasive medical applications.

Application of Macro-Instrumented Indentation Test for Superficial Residual Stress and Mechanical Properties Measurement for HY Steel Welded T-Joints.

HY-80 and HY-100 steels, widely used in constructing large ocean vessels and submarine hulls, contain mixed microstructures of tempered bainite and martensite and provide high tensile strength and toughness. Weld integrity in HY steels has been studied to verify and optimize welding conditions. In this study, the T-joint weld coupons, HY80 and HY100, were fabricated from HY-80 and HY-100 steel plates with a thickness of 30 mm as base metals by submerged-arc welding.

Self color-changing ordered mesoporous ceria for reagent-free colorimetric biosensing.

A reagent-free colorimetric detection method using mesoporous cerium oxide with a large pore size trapping an oxidative enzyme has been developed and glucose is sensitively detected with a limit of detection of 10 μM by supporting glucose oxidase on mesoporous cerium oxide.

N- and B-Codoped Graphene: A Strong Candidate To Replace Natural Peroxidase in Sensitive and Selective Bioassays.

The work describes a carbon-based peroxidase mimic, N- and B-codoped reduced graphene oxide (NB-rGO), which shows high peroxidase-like activity without oxidase-like activity and has a catalytic efficiency nearly 1000-fold higher than that of undoped rGO. The high catalytic activity of NB-rGO is explained by density functional theory by calculating Gibbs free energy change during the peroxide decomposition reaction. Acetylcholine and C-reactive protein are successfully quantified with high sensitivity and selectivity, which were comparable to or better than those obtained using natural peroxidase.

Biomechanical analysis of a changed posterior condylar offset under deep knee bend loading in cruciate-retaining total knee arthroplasty.

Background: The conservation of the joint anatomy is an important factor in total knee arthroplasty (TKA). The restoration of the femoral posterior condylar offset (PCO) has been well known to influence the clinical outcome after TKA.

Objective: The purpose of this study was to determine the mechanism of PCO in finite element models with conservation of subject anatomy and different PCO of ±1, ±2, ±3 mm in posterior direction using posterior cruciate ligament-retaining TKA.

Comparison of the biomechanical effect of posterior condylar offset and kinematics between posterior cruciate-retaining and posterior-stabilized total knee arthroplasty.

Background: The effect of the changes in the femoral posterior condylar offset (PCO) on anterior-posterior (AP) translation and internal-external (IE) rotation in cruciate-retaining (CR) and posterior-stabilized (PS) total knee arthroplasty (TKA) remains unknown. The purpose of this study was to compare the kinematics in CR and PS TKA with respect to the difference in prosthetic design and PCO change through a computational simulation.

Methods: We developed three-dimensional finite element models with the different PCOs of ±1, ±2 and ±3 mm in the posterior direction using CR and PS TKA.

Medical adhesive related skin injury after dental surgery.

An 87-year-old woman was referred for the extraction of residual teeth and removal of tori prior to prosthetic treatment. After surgery under general anesthesia, the surgical tape was removed to detach the bispectral index sensor and the hair cover. After the surgical tape was removed, skin injury occurred on the left side of her face.

Control of accumulated volatile fatty acids by recycling nitrified effluent.

Background: Volatile fatty acids (VFA) often accumulate in anaerobic digestion systems, decreasing pH levels and causing unstable operational performance and poor biogas production. The aim of this study is to improve anaerobic digestion efficiency by controlling/reducing the accumulation of VFAs in a continuous anaerobic digestion system.

Methods: NO -N was added to the digester and its effects on VFAs were investigated.

Comparison of Kinematics in Cruciate Retaining and Posterior Stabilized for Fixed and Rotating Platform Mobile-Bearing Total Knee Arthroplasty with respect to Different Posterior Tibial Slope.

Reconstructed posterior tibial slope (PTS) plays a significant role in kinematics restoration after total knee arthroplasty (TKA). However, the effect of increased and decreased PTS on prosthetic type and design has not yet been investigated. We used a finite element model, validated using in vitro data, to evaluate the effect of PTS on knee kinematics in cruciate-retaining (CR) and posterior-stabilized (PS) fixed TKA and rotating platform mobile-bearing TKA.

Effects of posterior condylar offset and posterior tibial slope on mobile-bearing total knee arthroplasty using computational simulation.

Background: Postoperative changes of the femoral posterior condylar offset (PCO) and posterior tibial slope (PTS) affect the biomechanics of the knee joint after fixed-bearing total knee arthroplasty (TKA). However, the biomechanics of mobile-bearing is not well known. Therefore, the aim of this study was to investigate whether alterations to the PCO and PTS affect the biomechanics for mobile-bearing TKA.

The increase in posterior tibial slope provides a positive biomechanical effect in posterior-stabilized total knee arthroplasty.

Purpose: This study aims to clarify the influence of the posterior tibial slope (PTS) on knee joint biomechanics after posterior-stabilized (PS) total knee arthroplasty (TKA) using a computer simulation.

Methods: A validated TKA computational model was used to evaluate and quantify the effects of an increased PTS. In order to conduct a squat simulation, models with a - 3° to 15° PTS using increments of 3° were developed.

Biomechanical Effects of Posterior Condylar Offset and Posterior Tibial Slope on Quadriceps Force and Joint Contact Forces in Posterior-Stabilized Total Knee Arthroplasty.

This study aimed to determine the biomechanical effect of the posterior condylar offset (PCO) and posterior tibial slope (PTS) in posterior-stabilized (PS) fixed-bearing total knee arthroplasty (TKA). We developed ±1, ±2, and ±3 mm PCO models in the posterior direction and -3°, 0°, 3°, and 6° PTS models using a previously validated FE model. The influence of changes in the PCO and PTS on the biomechanical effects under deep-knee-bend loading was investigated.

Association between Health Information Technology and Case Mix Index.

Objectives: Health information technology (IT) can assist healthcare providers in ordering medication and adhering to guidelines while improving communication among providers and the quality of care. However, the relationship between health IT and Case Mix Index (CMI) has not been thoroughly investigated; therefore, this study aimed to clarify this relationship.

Methods: To examine the effect of health IT on CMI, a generalized estimation equation (GEE) was applied to two years of California hospital data.

Influence of Increased Posterior Tibial Slope in Total Knee Arthroplasty on Knee Joint Biomechanics: A Computational Simulation Study.

Background: The reconstructed posterior tibial slope (PTS) plays a significant role in restoring knee kinematics in cruciate-retaining-total knee arthroplasty (TKA). A few studies have reported the effect of the PTS on biomechanics.

Methods: This study investigates the effect of the PTS on tibiofemoral (TF) kinematics, patellofemoral (PF) contact stress, and forces at the quadriceps, posterior cruciate ligament (PCL) and collateral ligament after cruciate-retaining-TKA using computer simulations.