Recent Advances in Functional Hydrogels for Treating Dental Hard Tissue and Endodontic Diseases.

Oral health is the basis of human health, and almost everyone has been affected by oral diseases. Among them, endodontic disease is one of the most common oral diseases. Limited by the characteristics of oral biomaterials, clinical methods for endodontic disease treatment still face large challenges in terms of reliability and stability. The hydrogel is a kind of good biomaterial with an adjustable 3D network structure, excellent mechanical properties, and biocompatibility and is widely used in the basic and clinical research of endodontic disease. This Review discusses the recent advances in functional hydrogels for dental hard tissue and endodontic disease treatment. The emphasis is on the working principles and therapeutic effects of treating different diseases with functional hydrogels. Finally, the challenges and opportunities of hydrogels in oral clinical applications are discussed and proposed. Some viewpoints about the possible development direction of functional hydrogels for oral health in the future are also put forward. Through systematic analysis and conclusion of the recent advances in functional hydrogels for dental hard tissue and endodontic disease treatment, this Review may provide significant guidance and inspiration for oral disease and health in the future.

Intelligent Recognition Using Ultralight Multifunctional Nano-Layered Carbon Aerogel Sensors with Human-Like Tactile Perception.

Humans can perceive our complex world through multi-sensory fusion. Under limited visual conditions, people can sense a variety of tactile signals to identify objects accurately and rapidly. However, replicating this unique capability in robots remains a significant challenge. Here, we present a new form of ultralight multifunctional tactile nano-layered carbon aerogel sensor that provides pressure, temperature, material recognition and 3D location capabilities, which is combined with multimodal supervised learning algorithms for object recognition. The sensor exhibits human-like pressure (0.04-100 kPa) and temperature (21.5-66.2 °C) detection, millisecond response times (11 ms), a pressure sensitivity of 92.22 kPa-1 and triboelectric durability of over 6000 cycles. The devised algorithm has universality and can accommodate a range of application scenarios. The tactile system can identify common foods in a kitchen scene with 94.63% accuracy and explore the topographic and geomorphic features of a Mars scene with 100% accuracy. This sensing approach empowers robots with versatile tactile perception to advance future society toward heightened sensing, recognition and intelligence.

A pathway analysis of the impact of childhood domestic violence on depression in middle-aged and elderly people from the perspective of life course.

BACKGROUND: Negative life events in early life have a cumulative effect on health trajectory changes in middle and old age, and some scholars have used life course theory as a guide to empirically explore the effect of childhood adversity or adverse experiences on depression in the elderly, but few study focuses on violence within the family. OBJECTIVE: To explore the influence mechanism of domestic violence experience on depression in later life in middle-aged and elderly people, and to provide academic support for the whole society to pay attention to good family function and intergenerational interaction, and to propose whole-life health promotion strategies. PARTICIPANTS AND SETTING: This paper selects the 2014 life course survey data and 2018 cross-sectional data of the China Health and Elderly Care Longitudinal Survey for analysis, and the research objects are middle-aged and elderly people aged 45 and above. METHODS: Based on a retrospective survey of 3008 middle-aged and elderly people, this study analyzed the influence path of domestic violence on depression level in childhood by using multiple mediation models, and used the Bootstrap method to test the significance of indirect effects. RESULTS: Based on controlling for gender, age, age square, household registration, marital status, community environment and education level, childhood domestic violence had a direct positive effect on depression level in the elderly (P < 0.001), and childhood domestic violence also had an indirect effect on the depression level of the elderly through childhood health status, income logarithm and IADL (P < 0.05). CONCLUSION: As a life experience in early life, childhood domestic violence has a cumulative effect on depression in middle-aged and elderly people, is an important risk factor for depression, and has an important impact on mental health in later life.

3D Extruded Graphene Thermoelectric Threads for Self-Powered Oral Health Monitoring.

Flexible sensors play a crucial role in intelligent electronic devices, while strain-sensing is the fundamental feature for these sensors of different fields. Therefore, developing high-performance flexible strain sensors is essential for building the next generation of smart electronics. Here, a self-powered ultrasensitive strain sensor based on graphene-based thermoelectric composite threads through a simple 3D extrusion method is reported. The optimized thermoelectric composite threads show a large stretchable strain of over 800%. After 1000 cycles of bending, the threads still maintain excellent thermoelectric stability. The thermoelectric effect-induced electricity can realize ultrasensitive strain and temperature detection with high resolution. As wearable devices, the thermoelectric threads can also realize self-powered physiological signals monitoring, including the opening degree of mouth, occlusal frequency, and force of the tooth during the eating process. It provides significant judgment and guidance for promoting oral healthcare and developing good eating habits.

Recent Advances in Pyroelectric Materials and Applications.

As one important subclass of piezoelectric materials, pyroelectric materials have caused increasing attention owing to the unique pyroelectric effect induced by spontaneous polarization, showing broad promising application prospects due to various electrical responses induced by time-dependent temperature variation. This review systematically introduces the pyroelectric effect and evaluation of pyroelectric materials and follows by analyzing and concluding the novel properties corresponding to four kinds of main pyroelectric materials. The emphasis of this review focuses on several significant and practical applications of pyroelectric materials in thermal energy harvesting from the external environment, pyroelectric sensing, and imaging, even some electrochemical applications including hydrogen generation, wastewater treatment, sterilization, and disinfection. Finally, the development direction of pyroelectric materials, potential challenges and opportunities in the future are all discussed and proposed. Through systematical conclusion and analysis of the latest research progress in the recent two decades, this review may provide significant guide and inspiration in the development of pyroelectric materials.

Hierarchically patterned self-powered sensors for multifunctional tactile sensing.

Flexible sensors are highly desirable for tactile sensing and wearable devices. Previous researches of smart elements have focused on flexible pressure or temperature sensors. However, realizing material identification remains a challenge. Here, we report a multifunctional sensor composed of hydrophobic films and graphene/polydimethylsiloxane sponges. By engineering and optimizing sponges, the fabricated sensor exhibits a high-pressure sensitivity of >15.22 per kilopascal, a fast response time of <74 millisecond, and a high stability over >3000 cycles. In the case of temperature stimulus, the sensor exhibits a temperature-sensing resolution of 1 kelvin via the thermoelectric effect. The sensor can generate output voltage signals after physical contact with different flat materials based on contact-induced electrification. The corresponding signals can be, in turn, used to infer material properties. This multifunctional sensor is excellent in its low cost and material identification, which provides a design concept for meeting the challenges in functional electronics.

Efficient water scavenging by cooling superhydrophobic surfaces to obtain jumping water droplets from air.

Dew collection is significant in harvesting water and relieving water shortages in arid regions. However, current methods for collecting dew or steam are mainly focusing on the millimeter-sized droplets condensed on the superhydrophobic surfaces. Here, we present a concept for harvesting micro droplets that can spontaneously bounce on the cooling superhydrophobic aluminum surface with randomly micro-nano composite structures, which were fabricated by using a two-step surface structural process. Moreover, an integrated device has been developed, which consists of a triboelectric nanogenerator and the superhydrophobic aluminum sheet. We experimentally explained that the triboelectric nanogenerator, which provides an external electric field by converting wind energy to electric energy with DC voltage pulse peaks of about 60 V, can be utilized to enhance the collection capacity of the jumping water droplets.

Laser-Etched Stretchable Graphene-Polymer Composite Array for Sensitive Strain and Viscosity Sensors.

The ability to control surface wettability and liquid spreading on textured surfaces is of interest for extensive applications. Soft materials have prominent advantages for producing the smart coatings with multiple functions for strain sensing. Here, we report a simple method to prepare flexible hydrophobic smart coatings using graphene-polymer films. Arrays of individual patterns in the films were created by laser engraving and controlled the contact angle of small drops by pinning the contact lines in a horizontal tensile range of 0-200%. By means of experiments and model, we demonstrate that the ductility of drops is relied on the height-to-spacing ratio of the individual pattern and the intrinsic contact angle. Moreover, the change of drop size was utilized to measure the applied strain and liquid viscosity, enabling a strain sensitivity as high as 1068 µm2/%. The proposed laser-etched stretchable graphene-polymer composite has potential applications in DNA microarrays, biological assays, soft robots, and so on.