Nanoparticle-based nanocomposite coatings with postprocessing for enhanced antimicrobial capacity of polymeric film.

Bacterial adhesion and biofilm formation on surfaces pose a significant risk of microbial contamination and chronic diseases, leading to potential health complications. To mitigate this concern, the implementation of antibacterial coatings becomes paramount in reducing pathogen propagation on contaminated surfaces. To address this requirement, our study focuses on developing cost-effective and sustainable methods using polymer composite coatings. Copper and titanium dioxide nanoparticles were used to assess their active antimicrobial functions. After coating the surface with nanoparticles, four different combinations of two postprocessing treatments were performed. Intense pulsed light was utilized to sinter the coatings further, and plasma etching was applied to manipulate the physical properties of the nanocomposite-coated sheet surface. Bacterial viability was comparatively analyzed at four different time points (0, 30, 60, and 120 min) upon contact with the nanocomposite coatings. The samples with nanoparticle coatings and postprocessing treatments showed an above-average 84.82% mortality rate at 30 min and an average of 89.77% mortality rate at 120 min of contact. In contrast, the control sample, without nanoparticle coatings and postprocessing treatments, showed a 95% microbe viability after 120 min of contact. Through this study, we gained critical insights into effective strategies for preventing the spread of microorganisms on high-touch surfaces, thereby contributing to the advancement of sustainable antimicrobial coatings.

Development of Antifreezing, Printable, Adhesive, Tough, Biocompatible, High-Water Content Hydrogel for Versatile Applications.

Hydrogels with different functionalities such as printability, antifreezing properties, adhesion, biocompatibility, and toughness are being continually developed. However, it has been extremely challenging to design adhesive, antifreezing, tough, and biocompatible multifunctional hydrogels with complex shapes simultaneously and prepare them in a short period. In this paper, novel composite hydrogels, which consist of poly(vinyl alcohol) grafted with styrylpyridinium group (PVA-SbQ) and TEMPO-oxidized cellulose nanofibrils (CNF), were successfully synthesized via UV photo-cross-linking. In addition to UV photo-cross-linking, the PVA-SbQ/CNF hydrogels with different shapes could be rapidly printed by facile visible light-based stereolithography printing and laser direct-writing without any photoinitiators in 3 min and 30 s, respectively. The results show that PVA-SbQ/CNF hydrogels are biocompatible because there are no photoinitiators and cross-linkers required during the printing process under visible light. Moreover, the adhesive, antifreezing, mechanical properties, and water-binding capacity of PVA-SbQ/CNF with high-water contents improved significantly as the CNF contents increased. Such hydrogels, which combine multiple advantages, present great potential for application in wound dressings and portable devices with specific requirements for shapes, adhesion, toughness, and tolerance in extreme environments such as dry environments and low temperatures.

Visible light laser direct-writing of high-resolution, biocompatible, super-multifunctional and tough hydrogels without photoinitiators in 30 s.

Currently, the lack of bioinks and long printing time limits the further development of biofabrication. Here we report a novel biocompatible, multi-functional and tough 3D printable hydrogel via visible light photocrosslinking of polyvinyl alcohol bearing styrylpyridinium group (PVA-SbQ). The high-resolution PVA-SbQ hydrogels with different designed shapes can be generated via laser direct-writing in 30 s without extra toxic crosslinkers or photoinitiators, and demonstrates excellent biocompatibility. The rapid laser direct-writing technology also results in a super-strong, tough hydrogel with excellent adhesive, swelling, self-healing, and photo-tunable properties due to the photodimerization of styrylpyridinium (SbQ) groups and the left-over massive amount of free hydroxyl groups in the hydrogel. For example, the maximum tensile strength, elongation, compressive strength adhesive strength of printed PVA-SbQ hydrogels can reach 1.0 MPa, 810 %, 33 MPa, 31 kPa, and 25,000 % respectively. And these properties can be adjusted by controlling the parameters for laser direct-writing. In addition, the introduced nitrogen cations by SbQ groups further endow hydrogels with the potential to develop novel functionality, which is demonstrated by integrating negatively charged nanocelluloses in the PVA-SbQ system to develop underwater adhesives, anti-freezing (-24.9 °C), and anti-bacterial hydrogels. This discovery opens multiple doors for developing PVA-SbQ based multi-functional hydrogel for various applications including biofabrication and tissue engineering.

Correction: Using Wake-Up Tasks for Morning Behavior Change: Development and Usability Study.

[This corrects the article DOI: 10.2196/39497.].

Using Wake-Up Tasks for Morning Behavior Change: Development and Usability Study.

BACKGROUND: Early morning behaviors between waking up and beginning daily work can develop into productive habits. However, sleep inertia limits the level of human ability immediately after waking, lowering a person's motivation and available time for productive morning behavior. OBJECTIVE: This study explores a design for morning behavior change using a wake-up task, a simple assignment the user needs to finish before alarm dismissal. Specifically, we set two research objectives: (1) exploring key factors that relate to morning behavior performance, including the use of wake-up tasks in an alarm app and (2) understanding the general practice of affecting morning behavior change by implementing wake-up tasks. METHODS: We designed and implemented an apparatus that provides wake-up task alarms and facilities for squat exercises. We recruited 36 participants to perform squat exercises in the early morning using the wake-up tasks for 2 weeks. First, we conducted a generalized estimating equation (GEE) analysis for the first research objective. Next, we conducted a thematic analysis of the postsurvey answers to identify key themes about morning behavior change with the wake-up tasks for the second objective. RESULTS: The use of wake-up tasks was significantly associated with both the completion of the target behavior (math task: P=.005; picture task: P<.001) and the elapsed time (picture task: P=.08); the time to alarm dismissal was significantly related to the elapsed time to completion (P<.001). Moreover, the theory of planned behavior (TPB) variables, common factors for behavior change, were significant, but their magnitudes and directions differed slightly from the other domains. Furthermore, the survey results reveal how the participants used the wake-up tasks and why they were effective for morning behavior performance. CONCLUSIONS: The results reveal the effectiveness of wake-up tasks in accomplishing the target morning behavior and address key factors for morning behavior change, such as (1) waking up on time, (2) escaping from sleep inertia, and (3) quickly starting the desired target behavior.

Optimized 3D Bioprinting Technology Based on Machine Learning: A Review of Recent Trends and Advances.

The need for organ transplants has risen, but the number of available organ donations for transplants has stagnated worldwide. Regenerative medicine has been developed to make natural organs or tissue-like structures with biocompatible materials and solve the donor shortage problem. Using biomaterials and embedded cells, a bioprinter enables the fabrication of complex and functional three-dimensional (3D) structures of the organs or tissues for regenerative medicine. Moreover, conventional surgical 3D models are made of rigid plastic or rubbers, preventing surgeons from interacting with real organ or tissue-like models. Thus, finding suitable biomaterials and printing methods will accelerate the printing of sophisticated organ structures and the development of realistic models to refine surgical techniques and tools before the surgery. In addition, printing parameters (e.g., printing speed, dispensing pressure, and nozzle diameter) considered in the bioprinting process should be optimized. Therefore, machine learning (ML) technology can be a powerful tool to optimize the numerous bioprinting parameters. Overall, this review paper is focused on various ideas on the ML applications of 3D printing and bioprinting to optimize parameters and procedures.

Micro/nanotechnology-inspired rapid diagnosis of respiratory infectious diseases.

Humans have suffered from a variety of infectious diseases since a long time ago, and now a new infectious disease called COVID-19 is prevalent worldwide. The ongoing COVID-19 pandemic has led to research of the effective methods of diagnosing respiratory infectious diseases, which are important to reduce infection rate and help the spread of diseases be controlled. The onset of COVID-19 has led to the further development of existing diagnostic methods such as polymerase chain reaction, reverse transcription polymerase chain reaction, and loop-mediated isothermal amplification. Furthermore, this has contributed to the further development of micro/nanotechnology-based diagnostic methods, which have advantages of high-throughput testing, effectiveness in terms of cost and space, and portability compared to conventional diagnosis methods. Micro/nanotechnology-based diagnostic methods can be largely classified into (1) nanomaterials-based, (2) micromaterials-based, and (3) micro/nanodevice-based. This review paper describes how micro/nanotechnologies have been exploited to diagnose respiratory infectious diseases in each section. The research and development of micro/nanotechnology-based diagnostics should be further explored and advanced as new infectious diseases continue to emerge. Only a handful of micro/nanotechnology-based diagnostic methods has been commercialized so far and there still are opportunities to explore.

Contrast reference values in panoramic radiographic images using an arch-form phantom stand.

PURPOSE: The purpose of this study was to investigate appropriate contrast reference values (CRVs) by comparing the contrast in phantom and clinical images. MATERIALS AND METHODS: Phantom contrast was measured using two methods: (1) counting the number of visible pits of different depths in an aluminum plate, and (2) obtaining the contrast-to-noise ratio (CNR) for 5 tissue-equivalent materials (porcelain, aluminum, polytetrafluoroethylene [PTFE], polyoxymethylene [POM], and polymethylmethacrylate [PMMA]). Four panoramic radiographs of the contrast phantom, embedded in the 4 different regions of the arch-form stand, and 1 real skull phantom image were obtained, post-processed, and compared. The clinical image quality evaluation chart was used to obtain the cut-off values of the phantom CRV corresponding to the criterion of being adequate for diagnosis. RESULTS: The CRVs were obtained using 4 aluminum pits in the incisor and premolar region, 5 aluminum pits in the molar region, and 2 aluminum pits in the temporomandibular joint (TMJ) region. The CRVs obtained based on the CNR measured in the anterior region were: porcelain, 13.95; aluminum, 9.68; PTFE, 6.71; and POM, 1.79. The corresponding values in the premolar region were: porcelain, 14.22; aluminum, 8.82; PTFE, 5.95; and POM, 2.30. In the molar region, the following values were obtained: porcelain, 7.40; aluminum, 3.68; PTFE, 1.27; and POM, - 0.18. The CRVs for the TMJ region were: porcelain, 3.60; aluminum, 2.04; PTFE, 0.48; and POM, - 0.43. CONCLUSION: CRVs were determined for each part of the jaw using the CNR value and the number of pits observed in phantom images.

BeUpright: Posture Correction Using Relational Norm Intervention.

Research shows the critical role of social relationships in behavior change, and the advancement of mobile technologies brings new opportunities of using online social support for persuasive applications. In this paper, we propose Relational Norm Intervention (RNI) model for behavior change, which involves two individuals as a target user and a helper respectively. RNI model uses Negative Reinforcement and Other-Regarding Preferences as motivating factors for behavior change. The model features the passive participation of a helper who will undergo artificially generated discomforts (e.g., limited access to a mobile device) when a target user performs against a target behavior. Based on in-depth discussions from a two-phase design workshop, we designed and implemented BeUpright, a mobile application employing RNI model to correct sitting posture of a target user. Also, we conducted a two-week study to evaluate the effectiveness and user experience of BeUpright. The study showed that RNI model has a potential to increase efficacy, in terms of behavior change, compared to conventional notification approaches. The most influential factor of RNI model in the changing the behavior of target users was the intention to avoid discomforting their helpers. RNI model also showed a potential to help unmotivated individuals in behavior change. We discuss the mechanism of RNI model in relation to prior literature on behavior change and implications of exploiting discomfort in mobile behavior change services.

Three-dimensional assessment of condylar surface changes and remodeling after orthognathic surgery.

PURPOSE: This study was performed to evaluate condylar surface changes and remodeling after orthognathic surgery using three-dimensional computed tomography (3D CT) imaging, including comparisons between the right and left sides and between the sexes. MATERIALS AND METHODS: Forty patients (20 males and 20 females) who underwent multi-detector CT examinations before and after surgery were selected. Three-dimensional images comprising thousands of points on the condylar surface were obtained before and after surgery. For the quantitative assessment of condylar surface changes, point-to-point (preoperative-to-postoperative) distances were calculated using D processing software. These point-to-point distances were converted to a color map. In order to evaluate the types of condylar remodeling, the condylar head was divided into six areas (anteromedial, anteromiddle, anterolateral, posteromedial, posteromiddle, and posterolateral areas) and each area was classified into three types of condylar remodeling (bone formation, no change, and bone resorption) based on the color map. Additionally, comparative analyses were performed between the right and left sides and according to sex. RESULTS: The mean of the average point-to-point distances on condylar surface was 0.11±0.03 mm. Bone resorption occurred more frequently than other types of condylar remodeling, especially in the lateral areas. However, bone formation in the anteromedial area was particularly prominent. No significant difference was found between the right and left condyles, but condylar surface changes in males were significantly larger than in females. CONCLUSION: This study revealed that condylar remodeling exhibited a tendency towards bone resorption, especially in the lateral areas. Condylar surface changes occurred, but were small.

Visual Loss After Intraoral Local Anesthesia for the Removal of Circumzygomatic and Circum-Mandibular Wires: A Case Report.

Many types of complications occur after intraoral local anesthesia; however, visual loss is a rare one. There have been only a few case reports of visual disturbance after intraoral local anesthesia. A 67-year-old man with systemic hypertension complained of visual disturbance after a dental local injection for circumzygomatic and circum-mandibular wire removal. Forty-nine days later, he had partly recovered his vision. To date, the exact mechanism of visual loss after dental injection remains unclear. This rare case could provide another clue to the etiology and caution against similar complications.

Treatment of extensive comminuted mandibular fracture between both mandibular angles with bilateral condylar fractures using a reconstruction plate: a case report.

This following case report describes the open reduction, internal fixation and the reconstruction of an extensive comminuted mandibular fracture with bilateral condylar fractures in a 19-year-old male patient with an intellectual disability and autistic disorder. He suffered fall trauma, resulting in shattered bony fragments of the alveolus and mandibular body between both mandibular rami, the fracture of both condyles and the avulsion or dislocation of every posterior tooth of the mandible. The patient underwent open reduction and internal fixation between both mandibular rami using a reconstruction plate, open reduction and internal fixation of the shattered fragments using miniplates and screws, and the closed reduction of the bilateral condylar fractures.

Corrigendum: Osteomyelitis Treated with Antibiotic Impregnated Polymethyl Methacrylate.

[This corrects the article on p. 396 in vol. 35.].

The three-dimensional microstructure of trabecular bone: Analysis of site-specific variation in the human jaw bone.

PURPOSE: This study was performed to analyze human maxillary and mandibular trabecular bone using the data acquired from micro-computed tomography (micro-CT), and to characterize the site-specific microstructures of trabeculae. MATERIALS AND METHODS: Sixty-nine cylindrical bone specimens were prepared from the mandible and maxilla. They were divided into 5 groups by region: the anterior maxilla, posterior maxilla, anterior mandible, posterior mandible, and mandibular condyle. After the specimens were scanned using a micro-CT system, three-dimensional microstructural parameters such as the percent bone volume, bone specific surface, trabecular thickness, trabecular separation, trabecular number, structure model index, and degrees of anisotropy were analyzed. RESULTS: Among the regions other than the condylar area, the anterior mandibular region showed the highest trabecular thickness and the lowest value for the bone specific surface. On the other hand, the posterior maxilla region showed the lowest trabecular thickness and the highest value for the bone specific surface. The degree of anisotropy was lowest at the anterior mandible. The condyle showed thinner trabeculae with a more anisotropic arrangement than the other mandibular regions. CONCLUSION: There were microstructural differences between the regions of the maxilla and mandible. These results suggested that different mechanisms of external force might exist at each site.