Characteristics of mandibular anterior alveolar bone in patients with different degrees of periodontitis: a retrospective study based on CBCT.

OBJECTIVES: To investigate the alveolar bone characteristics of mandibular anterior teeth in patients with periodontitis. MATERIALS AND METHODS: 100 patients with periodontitis were selected and grouped according to the degrees of alveolar bone resorption, age, gender, and tooth type. The labial thickness of the alveolar bone, the degree of alveolar bone resorption, angulation between the long axis of teeth and alveolar process, alveolar bone height and density of the mandibular anterior teeth were measured. RESULTS: There were significant differences in alveolar bone morphology between these three groups. Compared with the mild and moderate groups, the severe group showed that the alveolar bone in the half of the root crown was thickened, the alveolar bone height was decreased, the cancellous alveolar bone density was increased, and the cortical alveolar bone density was decreased. The resorption of alveolar bone was characterized by greater resorption of proximal bone than that of labial bone with increased bone loss. There were also differences in alveolar bone characteristics among patients of different ages, genders, and tooth types. CONCLUSIONS: The morphology of the mandibular anterior alveolar bone changed accordingly with the degree of periodontitis. Labial alveolar bone thickness and cortical alveolar bone density were negatively correlated with the degree of periodontitis, while alveolar bone height and cancellous alveolar bone density were positively correlated with the degree of periodontitis. CLINICAL RELEVANCE: These results allow clinicians to better understand the alveolar bone morphology of the mandibular anterior teeth in patients with periodontitis, facilitating better treatment design and avoiding complications.

An outcomes-based module education via flipped classroom enhances undergraduate oral histopathology learning.

INTRODUCTION: Oral histopathology is a bridge course connecting oral basic medicine and clinical dentistry. However, the application of outcomes-based education via flipped classroom (FC) in oral histopathology has not been well explored. This study has assessed the efficacy of outcomes-based education via FC in undergraduate oral histopathology module learning in Nanjing Medical University of China. MATERIALS AND METHODS: A total of 214 third-year students were enrolled and assigned to the FC group of the batch 2022-23 (n = 110) and the traditional classroom (TC) group of the batch 2021-22 (n = 104) to participate the oral histopathology sessions respectively in the study. The FC group were required to preview the online course materials pre-class, followed by in-class quizz, in-class interactive group discussion, and slides microscopic observation. The outcomes-based formative and summative assessments for FC were designed. The TC group attended traditional laboratory class for the same glass slides microscopic observation. In addition, a questionnaire was performed to investigate the satisfaction of learning. Along with this, the performances of FC group in written theory tests and oral histopathology slide tests were compared with TC group. RESULTS: Students in the FC group gained significantly final higher scores of the course than those in the TC group (score: 83.79 ± 11 vs. 76.73 ± 10.93, P<0.0001). Data from the student questionnaires indicated a preference for outcomes-based module education via FC. In the questionnaires, most students considered outcomes-based module education via FC to be beneficial to learning motivation, knowledge comprehension, critical thinking and teamwork. FC group had a higher level of satisfaction with oral histopathology teaching than TC group (satisfaction score: 4.599 ± 0.1027 vs. 4.423 ± 0.01366, P<0.01). CONCLUSION: An outcomes-based module education via FC has a promising effect on undergraduate oral histopathology education.

Clinical, radiographic characterizations and complications of maxillary molar in a periodontitis population: a retrospective study based on CBCT radiography.

OBJECTIVE: This study was aimed to delineate the clinical, CBCT radiographic characteristics, and complications of maxillary molar in a periodontitis population. MATERIALS AND METHODS: Medical records and CBCT images were utilized to identify adult patients with periodontitis in a tertiary referral dental hospital between June 2019 and December 2020. CBCT scan images were used to characterize the detailed bone thickness, absorbing height, and position of maxillary molar as well as their associated conditions. All relevant descriptive epidemiological data, clinical information, radiographic details, and associated complications were recorded and statistically analyzed. RESULTS: According to the above criteria, 577 eligible periodontitis patients were enrolled and defined as research cohort here with mean age 45 ± 4.8 years. Male patients outnumbered females with a gender ratio of 1.23:1. Our results demonstrated that the bone loss of maxillary first molar was more serious than that of second molar with tooth position symmetry. The occurrence of various complications (periodontal abscess, pulp lesions, furcation lesion, and mucosal thickening) was significantly correlated to periodontal-related clinical parameters of maxillary molar. CONCLUSIONS: Our results demonstrated the more serious bone loss of maxillary first molar with tooth position symmetry. The occurrence of various complications was significantly correlated to periodontal-related clinical parameters. Our findings offer valuable information concerning the clinical, radiographic characteristics, and complications of maxillary molar in a periodontitis population. CLINICAL RELEVANCE: These findings are beneficial for clinicians to comprehensively understand the bone status, pathogenesis, and clinical management of maxillary molar in periodontitis.

Mirror training device improves dental students' performance on virtual simulation dental training system.

INTRODUCTION: Clinical practice of dentistry entails the use of indirect vision using a dental mirror. The Mirrosistant is a device that helps dental students become proficient with use of indirect vision mirror operation. This study aimed to explore the role of the Mirrosistant on students' performance with the virtual simulation dental training system. MATERIALS AND METHODS: A total of 72 dental students were equally assigned to the Control group and the Experimental group. Subsequently, Mirrosistant was used to conduct a series of mirror training exercises in the Experimental group. The training consisted of tracing the edge and filling in the blank of the prescribed shape, as well as preparing the specified figure on raw eggs using indirect vision via Mirrosistant. Next, both groups were examined using the SIMODONT system, a virtual reality dental trainer, for mirror operation. In addition, a five-point Likert scale questionnaire was used to assess student feedback by using Mirrosistant. RESULTS: The mirror operation examination conducted by the SIMODONT system revealed that mirror training using Mirrosistant had statistically improved students' performances (score: 80.42 ± 6.43 vs. 69.89 ± 15.98, P = 0.0005) and shorten their performance time of mirror operation (time of seconds: 243.28 ± 132.83 vs. 328.53 ± 111.89, P = 0.0013). Furthermore, the questionnaire survey indicated that the participants had positive attitudes toward the mirror training using Mirrosistant. Most students believed that the mirror training device could improve their perceptions of direction and distance, as well as their sensations of dental operation and dental fulcrum. CONCLUSION: Mirror training using Mirrosistant can enhance dental students' mirror perceptual and operational skills on virtual simulation dental training system.

3D-printed swab with cover for precision diagnosis.

The collection capacity of common nasopharyngeal swabs and irregularities of medical personnel limit the accuracy of PCR testing. This study describes a newly designed 3D-printed swab that is combined with a 3D-printed cover to prevent the extraction of undesired nasal secretions. This swab improved the accuracy of PCR test results. The results of a series of experiments showed that, because of the mucus extraction effect, 3D-printed swabs can replace ordinary cotton swabs. The crisis of the worldwide medical supply shortage can be ameliorated to a certain extent by applying 3D printing technology.

An Activatable Polymeric Nanoprobe for Fluorescence and Photoacoustic Imaging of Tumor-Associated Neutrophils in Cancer Immunotherapy.

Imaging to evaluate tumor-associated neutrophils (TANs) is imperative for cancer immunotherapy but remains challenging. We herein report an activatable semiconducting polymer nanoprobe (SPCy) for near-infrared fluorescence (NIRF) and photoacoustic (PA) imaging of neutrophil elastase (NE), a biomarker of TANs. SPCy comprises a semiconducting polymer conjugated with a hemicyanine (hemi-Cy) dye caged by a NE-cleavable peptide as the side chain. After systemic administration, SPCy passively targets the tumor and reacts with NE to "uncage" the hemi-Cy, leading to enhanced NIRF and PA signals of the hemi-Cy but unchanged signals of the SP. Such NE-activated ratiometric NIRF and enhanced PA signals of SPCy correlate with the intratumoral population of TANs. Thus, this study not only presents the first TAN-specific PA probe, but also provides a general molecular design strategy for PA imaging of other immune-related biomarkers to facilitate screening of cancer immunotherapeutics.

Epidemiological, clinical, radiographic characterization of non-syndromic supernumerary teeth in Chinese children and adolescents.

OBJECTIVE: This retrospective study was purposed to evaluate epidemiological, clinical, and 3D radiological features of supernumerary teeth (ST) in a non-syndromic Chinese children and adolescent dental population. MATERIALS AND METHODS: Original cone-beam CT (CBCT) data from 18,861 patients aged from 6 to 17 years with dental maxillofacial diseases treated in a Chinese dental hospital from June 2012 to December 2018 were utilized to screen patients with ST. Diagnosis and characterizations of ST were analyzed by CBCT coupled with 3D reconstruction. All relevant epidemiological, clinical, and radiographic details about ST were collected and statistically analyzed. RESULTS: Among total 18,861 patients, 2,768 ST were identified in 1984 subjects with a prevalence of 10.52% and a male:female ratio of 1.86:1. Majority of ST were single, conical, inverted, impacted, and located in maxilla anterior region. ST-associated complications mainly included malposition, rotation, and impaction of adjacent teeth, which were notably associated with morphology and position of ST. CONCLUSION: The prevalence of ST in Chinese children and adolescent dental population was 10.52% and tended to present as single, conical, inverted, and impacted, which resulted in abnormalities of neighboring teeth. Our outcomes are beneficial for clinicians to more comprehensively understand the incidence, characterization, and clinical treatment planning of ST in dental children and adolescents.

Development of pp-LFER and QSPR models for predicting the diffusion coefficients of hydrophobic organic compounds in LDPE.

Diffusion coefficient (D) is important to evaluate the performance of passive samplers and to monitor the concentration of chemicals effectively. Herein, we developed a polyparameter linear free energy relationship (pp-LFER) model and a quantitative structure-property relationship (QSPR) model for the prediction of diffusion coefficients of hydrophobic organic contaminants (HOCs) in low density polyethylene (LDPE). A dataset of 120 various chemicals was used to develop both models. The pp-LFER model was developed with two descriptors (V and E) and the statistical parameters of the model showed satisfactory results. As a further exploration of the diffusion behavior of the compounds, a QSPR model with five descriptors (ETA_Alpha, ASP-6, IC1, TDB6r and ATSC2v) was constructed with adjusted determination coefficient (R2) of 0.949 and cross-validation coefficient (QLoo2) of 0.941. The regression results indicated that both models had satisfactory goodness-of-fit and robustness. This study proves that pp-LFER and QSPR approaches are available for the prediction of log D values for the hydrophobic organic compounds within the applicability domain.

Epidemiological, clinical, and 3-dimentional CBCT radiographic characterizations of supernumerary teeth in a non-syndromic adult population: a single-institutional study from 60,104 Chinese subjects.

OBJECTIVE: This study was aimed to delineate the prevalence, clinical, and 3-dimentional radiographic characteristics of adult supernumerary teeth (ST found) in a Chinese non-syndromic, dental population. MATERIALS AND METHODS: Medical records and cone beam computed tomography (CBCT) images were utilized to identify adult patients with ST in a tertiary referral dental hospital between June 2012 and December 2018. CBCT scan coupled with 3-dimentional reconstruction was used to characterize the detailed location, morphology, orientation of ST, and their relationship with adjacent teeth and neighboring structures. All relevant information regarding age and gender of patients, morphology, and 3-dimentional topography of ST as well as ST-associated complications were recorded and statistically analyzed. RESULTS: A total number of 1149 ST was identified in 921 eligible patients screened from 60,104 subjects with the prevalence of 1.5%. Male patients outnumbered females with a gender ratio of 1.76:1. The majority of ST was single, located in the maxilla, especially the maxillary central incisor region. Most ST were conical shape, inverted orientation, and impacted. ST-associated complications including impaction or root resorption of adjacent teeth, and cystic/tumor-like lesions were totally found in 13% ST and significantly associated with location, orientation, and morphology of ST. CONCLUSIONS: Most ST in Chinese adults were conical, inverted, impacted, and located in the maxillary central incisor region, and associated with various complications. Our findings offer valuable information concerning the prevalence, clinical, and radiographic characteristics of ST in non-syndromic Chinese adults. CLINICAL RELEVANCE: These findings are beneficial for clinicians to comprehensively understand the incidence, pathogenesis, and clinical management of ST.

Molecularly imprinted polymers for the detection of illegal drugs and additives: a review.

This review (with 154 refs.) describes the current status of using molecularly imprinted polymers in the extraction and quantitation of illicit drugs and additives. The review starts with an introduction into some synthesis methods (lump MIPs, spherical MIPs, surface imprinting) of MIPs using illicit drugs and additives as templates. The next section covers applications, with subsections on the detection of illegal additives in food, of doping in sports, and of illicit addictive drugs. A particular focus is directed towards current limitations and challenges, on the optimization of methods for preparation of MIPs, their applicability to aqueous samples, the leakage of template molecules, and the identification of the best balance between adsorption capacity and selectivity factor. At last, the need for convincing characterization methods, the lack of uniform parameters for defining selectivity, and the merits and demerits of MIPs prepared using nanomaterials are addressed. Strategies are suggested to solve existing problems, and future developments are discussed with respect to a more widespread use in relevant fields. Graphical abstract This review gives a comprehensive overview of the advances made in molecularly imprinting of polymers for use in the extraction and quantitation of illicit drugs and additives. Methods for syntheses, highlighted applications, limitations and current challenges are specifically addressed.

Mechanical Robustness Enhanced Flexible Antennas Using Ti3C2 MXene and Nanocellulose Composites for Noninvasive Glucose Sensing.

Electromagnetic sensors with flexible antennas as sensing elements have attracted increasing attention in noninvasive continuous glucose monitoring for diabetic patients. The significant radiation performance loss of flexible antennas during mechanical deformation impairs the reliability of glucose monitoring. Here, we present flexible ultrawideband monopole antennas composed of Ti3C2 MXene and cellulose nanofibril (CNF) composite films for continuous glucose monitoring. The flexible MXene/CNF antenna with 20% CNF content can obtain a gain of up to 3.33 dBi and a radiation efficiency of up to 65.40% at a frequency range from 2.3 to 6.0 GHz. Compared with the pure MXene antenna, this antenna offers a comparable radiation performance and a lower performance loss in mechanical bending deformation. Moreover, the MXene/CNF antenna shows a stable response to fetal bovine serum/glucose, with a correlation of >0.9 at the reference glucose levels, and responds sensitively to the variations in blood glucose levels during human trials. The proposed strategy enhancing the mechanical robustness of MXene-based flexible antennas makes metallic two-dimensional nanomaterials more promising in wearable electromagnetic sensors.

Enhanced Mechanical Properties, Corrosion Resistance, Cytocompatibility, Osteogenesis, and Antibacterial Performance of Biodegradable Mg-2Zn-0.5Ca-0.5Sr/Zr Alloys for Bone-Implant Application.

Magnesium (Mg) alloys are widely used in bone fixation and bone repair as biodegradable bone-implant materials. However, their clinical application is limited due to their fast corrosion rate and poor mechanical stability. Here, the development of Mg-2Zn-0.5Ca-0.5Sr (MZCS) and Mg-2Zn-0.5Ca-0.5Zr (MZCZ) alloys with improved mechanical properties, corrosion resistance, cytocompatibility, osteogenesis performance, and antibacterial capability is reported. The hot-extruded (HE) MZCZ sample exhibits the highest ultimate tensile strength of 255.8 ± 2.4 MPa and the highest yield strength of 208.4 ± 2.8 MPa and an elongation of 15.7 ± 0.5%. The HE MZCS sample shows the highest corrosion resistance, with the lowest corrosion current density of 0.2 ± 0.1 µA cm-2 and the lowest corrosion rate of 4 ± 2 µm per year obtained from electrochemical testing, and a degradation rate of 368 µm per year and hydrogen evolution rate of 0.83 ± 0.03 mL cm-2 per day obtained from immersion testing. The MZCZ sample shows the highest cell viability in relation to MC3T3-E1 cells among all alloy extracts, indicating good cytocompatibility except at 25% concentration. Furthermore, the MZCZ alloy shows good antibacterial capability against Staphylococcus aureus.

Electrospun gelatin-based biomimetic scaffold with spatially aligned and three-layer architectures for vascular tissue engineering.

The spatial cellular alignment and multi-layer structure are vitally important for the physiological functions of natural blood vessels. However, the two features are difficult to be constructed in one scaffold simultaneously, especially in the small-diameter vascular scaffold. Here we report a general strategy to construct a gelatin-based biomimetic three-layer vascular scaffold with spatial alignment features mimicking the natural structure of blood vessels. By using a sequential electrospinning strategy combined with folding and rolling manipulation, a three-layer vascular scaffold with inner and middle layers spatially perpendicular to each other was obtained. The special features of this scaffold could fully mimic the natural multi-layer structures of blood vessels and also possess great potential for spatial arrangement guidance of corresponding cells in blood vessels.

Microplastics in infant milk powder.

Microplastics can be found almost everywhere and extensively expose to human. Infants are vulnerable, and the potential risks of microplastics may be greater for infants, however, infants' microplastic exposure is still poorly understood. Since milk powder makes up a significant portion of many infants' diets, we investigated microplastic pollution in infant milk powder and calculated the microplastic exposure from milk powder, feeding bottles and milk powder preparation. On one hand, we studied 13 different types of milk powder with different packaging, processing systems, and milk sources. The boxed milk powder (7 ± 3 items/100 g) was more polluted with microplastics than the canned milk powder (4 ± 3 items/100 g). The inner packaging of the boxed milk powder was plastic and aluminum foil laminated, it emitted 8 ± 2 to 17 ± 1 items/100 g of microplastics, and might be a main source of microplastics in boxed milk powder. On the other hand, we found that when infants consume milk powder, the microplastic exposure from milk powder itself is little, exposure from feeding bottles is 6.8 times higher than that from milk powder and milk powder preparation is 1.7 times higher.

Acidity-Activated Charge Conversion of 177Lu-Labeled Nanoagent for the Enhanced Photodynamic Radionuclide Therapy of Cancer.

Nanomaterials in combination with radionuclide therapy (RNT) provide new opportunities for cancer treatment. However, nanomaterials with efficient tumor accumulation have been less exploited for effective radionuclide-based therapy. Here, we report glycol chitosan-based nanoparticles (GCP-NPs) with acidic pH-dependent surface charge conversion for efficient radionuclide-based combination therapy. The nanoplatform can change the surface charge of nanoparticles from slight negative to positive in the acidic tumor microenvironment, which facilitates cellular internalization and penetration and thus improves the tumor accumulation efficiency of nanomaterials. Radiolabeling of GCP-NPs with 99mTc enables in vivo radioactive imaging in the mouse subcutaneous tumor model, showing 8.1-fold enhanced tumor uptake relative to pH-insensitive control nanoparticles (termed as GCOP-NPs). Afterward, therapeutic radioisotope 177Lu-labeled GCP-NPs (177Lu-GCP-NPs) that utilize RNT synergistic with photodynamic therapy (PDT) derived from conjugated pyropheophorbide-a within nanoparticles endow superior antitumor efficacy in living cells and tumor-bearing mouse model. More importantly, the combination of RNT and PDT using 177Lu-GCP-NPs can effectively inhibit lung metastasis and eliminate splenomegaly, which is not possible for individual RNT or PDT. Therefore, this study proposes a facile radionuclide-based combination therapy strategy toward complete cancer remission.

Interfacially Locked Metal Aerogel Inside Porous Polymer Composite for Sensitive and Durable Flexible Piezoresistive Sensors.

Flexible pressure sensors play significant roles in wearable devices, electronic skins, and human-machine interface (HMI). However, it remains challenging to develop flexible piezoresistive sensors with outstanding comprehensive performances, especially with excellent long-term durability. Herein, a facile "interfacial locking strategy" has been developed to fabricate metal aerogel-based pressure sensors with excellent sensitivity and prominent stability. The strategy broke the bottleneck of the intrinsically poor mechanical properties of metal aerogels by grafting them on highly elastic melamine sponge with the help of a thin polydimethylsiloxane (PDMS) layer as the interface-reinforcing media. The hierarchically porous conductive structure of the ensemble offered the as-prepared flexible piezoresistive sensor with a sensitivity as high as 12 kPa-1 , a response time as fast as 85 ms, and a prominent durability over 23 000 compression cycles. The excellent comprehensive performance enables the successful application of the flexible piezoresistive sensor as two-dimensional (2D) array device as well as three-dimensional (3D) force-detecting device for real-time monitoring of HMI activities.

A preliminary study on polycaprolactone and gelatin-based bilayered tubular scaffolds with hierarchical pore size constructed from nano and microfibers for vascular tissue engineering.

Due to the insufficient endothelialization and the poor colonization of smooth muscle cells (SMCs), small-diameter vascular tissue engineering is still challenging. An ideal vascular graft is expected to effectively support the formation of endothelial monolayer and the colonization of SMCs. In this study, we proposed a bilayered scaffold with hierarchical pore size constructed from nano and microfibers by electrospinning PCL-PEG-PCL (PCE) and a blend of PCE and gelatin (PCEG) sequentially. The structural features of nano and microfibers were tuned by the concentration of PCE and the proportion of PCE/gelatin in electrospun solution respectively. The results demonstrated the best nanofiber morphology and relatively high mechanical properties were achieved in 18% PCE (w/v) (PCE18) and PCE and gelatin with a weight ratio of 7:3 (P7G3) at a concentration of 18% (w/v) electrospun membranes. The in vitro co-culturing studies of cells and membranes indicated all the PCE membranes supported the proliferation and spreading of endothelial cells and the further endothelialization of the membranous surface, while PCEG membranes facilitated the migration inward of SMCs. Taking the porosity and mechanical properties into consideration, PCE18 and P7G3 were chosen to construct the inner and outer layers of the bilayered scaffold with hierarchical pore size respectively. The circumferential ring test demonstrated that the bilayered scaffold has good mechanical property both in dry and wet state. After cells were co-cultured with this bilayered scaffold for 7 days, the results manifested a continuous endothelial monolayer has formed on the luminal surface and the SMCs have started to colonized from outer layers, indicating the vast potential of this bilayered scaffold in vascular remodeling and regeneration.

Two new species of the genus Symphylella (Symphyla, Scolopendrellidae) from Tibet, China.

The Symphyla of Tibet are studied for the first time. Symphylellamacropora sp. n. and Symphylellazhongi sp. n. from southeastern Tibet are described and illustrated. Symphylellamacropora sp. n. is characterized by large, elongated oval openings of the Tömösváry organ with its inner margins covered by minute irregular teeth, rudimentary spined sensory organs present on the dorsal side of most antennal segments, and cerci with numerous long and slightly curved setae. Symphylellazhongi sp. n. is characterized by a globular Tömösváry organ with a small and roundish opening, mushroom-shaped sensory organs present on apical antennal segments, and by having tergal processes longer than their basal width with ovoid swollen ends. The newly described species are compared to the morphologically closest congeners: S.javanensis, S.asiatica, S.multisetosa, and S.simplex. A key for 43 species of the genus is also provided.

Fabrication, characterization and biocompatibility of collagen/oxidized regenerated cellulose-Ca composite scaffold for carrying Schwann cells.

Schwann cell (SC) is the primary structural and functional part of the peripheral nervous system, and it plays a key role in the repair and regeneration of peripheral nerve. In order to develop a suitable scaffold for SC nerve tissue engineering, three kinds of scaffolds, including pristine collagen, pure oxidized regenerated cellulose-Ca (ORCCa) and collagen/ORC-Ca composite scaffolds, have been fabricated for carrying SC in this study. SC is then seeded on the scaffolds to form SC-scaffold nerve tissue engineering composites and evaluate their biocompatibility. The chemical and physical structure of the scaffolds are investigated by FTIR, NMR and SEM. The wettability of the collagen/ORC-Ca composite scaffold is close to that of pristine collagen, and the tensile strength of the composite scaffold (0.58 MPa) is better than that of pristine collagen (0.36 MPa). Cytotoxicity, cell proliferation, cell adhesion and western blotting assays are conducted to evaluate the biocompatibility and properties of different scaffolds. The results show that the three scaffolds exhibit no toxicity, and the proliferation rate of SC on the collagen/ORC-Ca composite scaffold is significantly higher than that of the other scaffolds (p < 0.05). The number of the adhesion cells on the composite scaffold (244.67 ±â€¯13.02) is much more than that in the pure ORC-Ca group (p < 0.01). Furthermore, the expression of N-Cadheri and PMP22 proteins in the collagen/ORC-Ca composite scaffold is significantly superior to the other two scaffolds (both p < 0.01). Therefore, it could be concluded that the collagen/ORC-Ca composite is a promising candidate as a scaffold for carrying SC to form nerve tissue engineering composites in order to assist the peripheral nervous in the repair and regeneration.