Doping Engineering of Conductive Polymers and Their Application in Physical Sensors for Healthcare Monitoring.

Physical sensors have emerged as a promising technology for real-time healthcare monitoring, which tracks various physical signals from the human body. Accurate acquisition of these physical signals from biological tissue requires excellent electrical conductivity and long-term durability of the sensors under complex mechanical deformation. Conductive polymers, combining the advantages of conventional polymers and organic conductors, are considered ideal conductive materials for healthcare physical sensors due to their intrinsic conductive network, tunable mechanical properties, and easy processing. Doping engineering has been proposed as an effective approach to enhance the sensitivity, lower the detection limit, and widen the operational range of sensors based on conductive polymers. This approach enables the introduction of dopants into conductive polymers to adjust and control the microstructure and energy levels of conductive polymers, thereby optimizing their mechanical and conductivity properties. This review article provides a comprehensive overview of doping engineering methods to improve the physical properties of conductive polymers and highlights their applications in the field of healthcare physical sensors, including temperature sensors, strain sensors, stress sensors, and electrophysiological sensing. Additionally, the challenges and opportunities associated with conductive polymer-based physical sensors in healthcare monitoring are discussed.

Hydrogel-Based Bioelectronics and Their Applications in Health Monitoring.

Flexible bioelectronics exhibit promising potential for health monitoring, owing to their soft and stretchable nature. However, the simultaneous improvement of mechanical properties, biocompatibility, and signal-to-noise ratio of these devices for health monitoring poses a significant challenge. Hydrogels, with their loose three-dimensional network structure that encapsulates massive amounts of water, are a potential solution. Through the incorporation of polymers or conductive fillers into the hydrogel and special preparation methods, hydrogels can achieve a unification of excellent properties such as mechanical properties, self-healing, adhesion, and biocompatibility, making them a hot material for health monitoring bioelectronics. Currently, hydrogel-based bioelectronics can be used to fabricate flexible bioelectronics for motion, bioelectric, and biomolecular acquisition for human health monitoring and further clinical applications. This review focuses on materials, devices, and applications for hydrogel-based bioelectronics. The main material properties and research advances of hydrogels for health monitoring bioelectronics are summarized firstly. Then, we provide a focused discussion on hydrogel-based bioelectronics for health monitoring, which are classified as skin-attachable, implantable, or semi-implantable depending on the depth of penetration and the location of the device. Finally, future challenges and opportunities of hydrogel-based bioelectronics for health monitoring are envisioned.

A Flexible Piezocapacitive Pressure Sensor with Microsphere-Array Electrodes.

Flexible pressure sensors that emulate the sensation and characteristics of natural skins are of great importance in wearable medical devices, intelligent robots, and human-machine interfaces. The microstructure of the pressure-sensitive layer plays a significant role in the sensor's overall performance. However, microstructures usually require complex and costly processes such as photolithography or chemical etching for fabrication. This paper proposes a novel approach that combines self-assembled technology to prepare a high-performance flexible capacitive pressure sensor with a microsphere-array gold electrode and a nanofiber nonwoven dielectric material. When subjected to pressure, the microsphere structures of the gold electrode deform via compressing the medium layer, leading to a significant increase in the relative area between the electrodes and a corresponding change in the thickness of the medium layer, as simulated in COMSOL simulations and experiments, which presents high sensitivity (1.807 kPa-1). The developed sensor demonstrates excellent performance in detecting signals such as slight object deformations and human finger bending.

Recent progress on performances and mechanisms of carbon dots for gas sensing.

Carbon dots (CDs), as an attractive zero-dimensional carbon nanomaterial with unique photoluminescent merits, have recently exhibited significant application potential in gas sensing as a result of their excellent optical/electronic characteristics, high chemical/thermal stability, and tunable surface states. CDs exhibit strong light absorption in the ultraviolet range and tunable photoluminescence characteristics in the visible range, which makes CDs an effective tool for optical sensing applications. Optical gas sensor based on CDs have been investigated, which generally responds to the target gas by corresponding changes in optical absorption or fluorescence. Moreover, electrical gas sensor and quartz crystal microbalance sensor whose sensing layer involves CDs have also been designed. Electrical gas sensor exhibits an increase or a decrease in electrical current, capacitance, or conductance once exposed to the target gas. Quartz crystal microbalance sensor responds to the target gas with a frequency shift. CDs greatly promote the absorption of the target gas and improve the sensitivity of both sensors. In this review, we aim to summarize different types of gas sensors involving CDs, and sensing performances of these sensors for monitoring diverse gases or vapors, as well as the mechanisms of CDs in different types of sensors. Moreover, this review provides the prospect of the potential development of CDs based gas sensors.

Versatile self-assembled electrospun micropyramid arrays for high-performance on-skin devices with minimal sensory interference.

On-skin devices that show both high performance and imperceptibility are desired for physiological information detection, individual protection, and bioenergy conversion with minimal sensory interference. Herein, versatile electrospun micropyramid arrays (EMPAs) combined with ultrathin, ultralight, gas-permeable structures are developed through a self-assembly technology based on wet heterostructured electrified jets to endow various on-skin devices with both superior performance and imperceptibility. The designable self-assembly allows structural and material optimization of EMPAs for on-skin devices applied in daytime radiative cooling, pressure sensing, and bioenergy harvesting. A temperature drop of ~4 °C is obtained via an EMPA-based radiative cooling fabric under a solar intensity of 1 kW m-2. Moreover, detection of an ultraweak fingertip pulse for health diagnosis during monitoring of natural finger manipulation over a wide frequency range is realized by an EMPA piezocapacitive-triboelectric hybrid sensor, which has high sensitivity (19 kPa-1), ultralow detection limit (0.05 Pa), and ultrafast response (≤0.8 ms). Additionally, EMPA nanogenerators with high triboelectric and piezoelectric outputs achieve reliable biomechanical energy harvesting. The flexible self-assembly of EMPAs exhibits immense potential in superb individual healthcare and excellent human-machine interaction in an interference-free and comfortable manner.

Bilateral Maxillary Langerhans Cell Histiocytosis in a Six-Month-Old Infant.

Langerhans cell histiocytosis (LCH) is a rare proliferative disease of myeloid cells that can affect multiple organs and present with diverse clinical manifestations. The skeleton, skin and lymph nodes are commonly affected sites, while oral involvement is rare. LCH is currently classified by disease extent into single system and multisystem forms, and further categorized by risk organs. The purpose of this report is to describe the case of a six-month-old girl who presented with a chief complaint of feeding difficulties, premature eruption of the primary left maxillary second molar, expansion of the maxillary alveolar ridges and ulceration of the posterior maxillary oral mucosa. The diverse presentations of pediatric LCH in the literature are reviewed and the role of pediatric dentists and oral surgeons in helping to diagnose LCH is highlighted.

Skin-Attachable Sensors for Biomedical Applications.

With the growing concern about human health issues, especially during the outbreak of the COVID-19 pandemic, the demand for personalized healthcare regarding disease prevention and recovery is increasing. However, tremendous challenges lie in both limited public medical resources and costly medical diagnosis approaches. Recently, skin-attachable sensors have emerged as promising health monitoring platforms to overcome such difficulties. Owing to the advantages of good comfort and high signal-to-noise ratio, skin-attachable sensors enable household, real-time, and long-term detection of weak physiological signals to efficiently and accurately monitor human motion, heart rate, blood oxygen saturation, respiratory rate, lung and heart sound, glucose, and biomarkers in biomedical applications. To further improve the integration level of biomedical skin-attachable sensors, efforts have been made in combining multiple sensing techniques with elaborate structural designs. This review summarizes the recent advances in different functional skin-attachable sensors, which monitor physical and chemical indicators of the human body. The advantages, shortcomings, and integration strategies of different mechanisms are presented. Specially, we highlight sensors monitoring pulmonary function such as respiratory rate and blood oxygen saturation for their potential usage in the COVID-19 pandemic. Finally, the future development of skin-attachable sensors is envisioned.

Focus calibration method based on the illumination beam scanning angle modulation in a grating alignment system.

A focus calibration method is developed to determine the focus position of a grating alignment system. An illumination beam scanning module is utilized to generate a circular motion for the beam, which forms an angular modulation interference image on the reference mark. A theoretical model is presented to determine the focus by determining the alignment grating z-position, at which the alignment offset is independent of the incident beam tilt. The standard uncertainty of the focus calibration results is estimated to be better than 150 nm. This technique may improve the measurement performance for lithography systems and precision machine applications.

Nanomaterials and their applications on bio-inspired wearable electronics.

Wearable electronics featuring conformal attachment, sensitive perception and intellectual signal processing have made significant progress in recent years. However, when compared with living organisms, artificial sensory devices showed undeniable bulky shape, poor adaptability, and large energy consumption. To make up for the deficiencies, biological examples provide inspirations of novel designs and practical applications. In the field of biomimetics, nanomaterials from nanoparticles to layered two-dimensional materials are actively involved due to their outstanding physicochemical properties and nanoscale configurability. This review focuses on nanomaterials related to wearable electronics through bioinspired approaches on three different levels, interfacial packaging, sensory structure, and signal processing, which comprehensively guided recent progress of wearable devices in leveraging both nanomaterial superiorities and biorealistic functionalities. In addition, opinions on potential development trend are proposed aiming at implementing bioinspired electronics in multifunctional portable sensors, health monitoring, and intelligent prosthetics.

Coating film and asymmetric amplitude difference effects on measurement performance in phase grating interference-based metrology.

In this study, the effects of the coating film thickness on a grating interferometry system were analyzed. The asymmetry-induced error of the deformed phase grating varied periodically with the coating film thickness, due to the spurious interference of multiple reflections in the film layer and asymmetry in the amplitudes of the diffraction orders, which led to phase offsets (and thus position errors). The average error obtained with a multiorder interferometer was compared to that simulated by atomic force microscopy. The simulation and measurement results were consistent with the theoretical analysis, which will facilitate accurate measurement error analysis.

External Modulation Laser Module Assembly for Improving Measurement Performance of Homodyne Interferometry.

An external modulation laser module assembly (EMLMA) is proposed to suppress nonlinear errors in an interferometry system and improve its measurement performance. The EMLMA employs both phase modulation with radio frequency signal and a specific modulation amplitude switching mode, enabling the suppression of noise introduced by spurious reflections. The amplitude modulation reduces the influence of stray and background light by transforming the signal of interest to a high-frequency bandwidth. Experimental results show that the measurement error and stability of the interferometry system are significantly improved using the proposed light source module. After modulation, the spurious reflection-induced offset is decreased, and the measurement resolution improves from 7 to 2 nm. The EMLMA can replace the light source of any interferometric measurement system without altering the optical measurement structure. The proposed method reduces the influence of nonlinear errors in homodyne interferometry and provides a basis for further improvement of the interferometry performance.

MXenes and Their Applications in Wearable Sensors.

MXenes, a kind of two-dimensional material of early transition metal carbides and carbonitrides, have emerged as a unique class of layered-structured metallic materials with attractive features, as good conductivity comparable to metals, enhanced ionic conductivity, hydrophilic property derived from their hydroxyl or oxygen-terminated surfaces, and mechanical flexibility. With tunable etching methods, the morphology of MXenes can be effectively controlled to form nanoparticles, single layer, or multi-layer nanosheets, which exhibit large specific surface areas and is favorable for enhancing the sensing performance of MXenes based sensors. Moreover, MXenes are available to form composites with other materials facilely. With structure design, MXenes or its composite show enhanced mechanical flexibility and stretchability, which enabled its wide application in the fields of wearable sensors, energy storage, and electromagnetic shielding. In this review, recent progress in MXenes is summarized, focusing on its application in wearable sensors including pressure/strain sensing, biochemical sensing, temperature, and gas sensing. Furthermore, the main challenges and future research are also discussed.

Systematic review of the use of pentoxifylline and tocopherol for the treatment of medication-related osteonecrosis of the jaw.

OBJECTIVE: Medication-related osteonecrosis of the jaw (MRONJ) is a pathologic process resulting in progressive destruction of the jaws. There are no established guidelines for the medical management of MRONJ. Interest in pentoxifylline and tocopherol is growing because these agents have been shown to be effective in treating osteoradionecrosis of the jaw. This review evaluates the clinical usefulness of pentoxifylline and tocopherol in treating MRONJ. STUDY DESIGN: Literature databases were searched for relevant reports of pentoxifylline and tocopherol in treating MRONJ. Only English-language reports and human studies were considered. RESULTS: There were 3 published observational studies and 2 abstracts relevant to this topic. The combination of pentoxifylline and tocopherol is associated with subjective and objective improvements and no major adverse outcomes. CONCLUSIONS: Pentoxifylline and tocopherol has been demonstrated to be effective for managing MRONJ nonsurgically, and, thus, this treatment modality holds promise. However, larger clinical studies are needed to optimize dose and duration.

Differential Effects of Antiretroviral Drugs on Neurons In Vitro: Roles for Oxidative Stress and Integrated Stress Response.

Mounting evidence suggests that antiretroviral drugs may contribute to the persistence of HIV-associated neurocognitive disorders (HAND), which impact 30%-50% of HIV-infected patients in the post-antiretroviral era. We previously reported that two first generation HIV protease inhibitors, ritonavir and saquinavir, induced oxidative stress, with subsequent neuronal death in vitro, which was reversed by augmentation of the endogenous antioxidant response by monomethyl fumarate. We herein determined whether two newer-generation PIs, darunavir and lopinavir, were deleterious to neurons in vitro. Further, we expanded our assessment to include three integrase strand transfer inhibitors, raltegravir, dolutegravir, and elvitegravir. We found that only lopinavir and elvitegravir were neurotoxic to primary rat neuroglial cultures as determined by the loss of microtubule-associated protein 2 (MAP2). Intriguingly, lopinavir but not elvitegravir led to oxidative stress and induced the endogenous antioxidant response (EAR). Furthermore, neurotoxicity of lopinavir was blocked by pharmacological augmentation of the endogenous antioxidant heme oxygenase-1 (HO-1), expanding our previous finding that protease inhibitor-induced neurotoxicity was mediated by oxidative stress. Conversely, elvitegravir but not lopinavir led to increased eIF2α phosphorylation, indicating the activation of a common adaptive pathway termed the integrated stress response (ISR), and elvitegravir-mediated neurotoxicity was partially alleviated by the ISR inhibitor trans-ISRIB, suggesting ISR as a promoter of elvitegravir-associated neurotoxicity. Overall, we found that neurotoxicity was induced only by a subset of protease inhibitors and integrase strand transfer inhibitors, providing evidence for class- and drug-specific neurotoxic effects of antiretroviral drugs. Future in vivo studies will be critical to confirm the neurotoxicity profiles of these drugs for incorporation of these findings into patient management. The EAR and ISR pathways are potential access points for the development of adjunctive therapies to complement antiretroviral therapies and limit their contribution to HAND persistence.

Effects of Specimen Collection Methodologies and Storage Conditions on the Short-Term Stability of Oral Microbiome Taxonomy.

UNLABELLED: Community profiling of the oral microbiome requires the recovery of quality sequences in order to accurately describe microbial community structure and composition. Our objective was to assess the effects of specimen collection method, storage medium, and storage conditions on the relative abundance of taxa in saliva and plaque identified using 16S rRNA genes. We also assessed short-term changes in taxon composition and relative abundance and compared the salivary and dental plaque communities in children and adults. Over a 2-week period, four successive saliva and dental plaque specimens were collected from four adults with no dental decay (108 samples), and two successive specimens were collected from six children with four or more erupted teeth (48 samples). There were minimal differences in community composition at the phylum and operational taxonomic unit levels between dental plaque collection using a scaler and collection using a CytoSoft brush. Plaque samples stored in OMNIgene medium showed higher within-sample Shannon diversity, were compositionally different, and were more similar to each other than plaque stored in liquid dental transport medium. Saliva samples stored in OMNIgene recovered similar communities for at least a week following storage at room temperature. However, the microbial communities recovered from plaque and saliva stored in OMNIgene were significantly different in composition from their counterparts stored in liquid dental transport medium. Dental plaque communities collected from the same tooth type over four successive visits from the same adult did not significantly differ in structure or composition. IMPORTANCE: Large-scale epidemiologic studies require collection over time and space, often with multiple teams collecting, storing, and processing data. Therefore, it is essential to understand how sensitive study results are to modest changes in collection and storage protocols that may occur with variation in personnel, resources available at a study site, and shipping requirements. The research presented in this paper measures the effects of multiple storage parameters and collection methodologies on the measured ecology of the oral microbiome from healthy adults and children. These results will potentially enable investigators to conduct oral microbiome studies at maximal efficiency by guiding informed administrative decisions pertaining to the necessary field or clinical work.