Highly Crystalline Copper Aluminum-Layered Double Hydroxides with Intrinsic Fenton-Like Catalytic Activity for Robust Oral Health Management.

As the main challenge of dental healthcare, oral infectious diseases are highly associated with the colonization of pathogenic microbes. However, current antibacterial treatments in the field of stomatology still lack a facile, safe, and universal approach. Herein, we report the controllable synthesis of copper aluminum-layered double hydroxides (CuAl-LDHs) with high Fenton-like catalytic activity, which can be utilized in the treatment of oral infectious diseases with negligible side effects. Our strategy can efficiently avoid the unwanted doping of other divalent metal ions in the synthesis of Cu-contained LDHs and result in the formation of binary CuAl-LDHs with high crystallinity and purity. Evidenced by experimental and theoretical results, CuAl-LDHs exhibit excellent catalytic ability toward the ·OH generation in the presence of H2O2 and hold strong affinity toward bacteria, endowing them with great catalytic sterilization against both Gram-positive and Gram-negative bacteria. As expected, these CuAl-LDHs provide outstanding treatments for mucosal infection and periodontitis by promoting wound healing and remodeling of the periodontal microenvironment. Moreover, toxicity investigation demonstrates the overall safety. Accordingly, the current study not only provides a convenient and economic strategy for treating oral infectious diseases but also extends the development of novel LDH-based Fenton or Fenton-like antibacterial reagents for further biomedical applications.

Impact of Coronavirus disease 2019 on patients with toothache: Analysis of tweets on Weibo.

OBJECTIVE: The aim of this study is to investigate the impact of Coronavirus disease 2019 (COVID-19) on toothache patients through posts on Sina Weibo. METHODS: Using Gooseeker, we searched and screened 24,108 posts about toothache on Weibo during the dental clinical closure period of China (February 1, 2020-February 29, 2020), and then divided them into 4 categories (causes of toothache, treatments of toothache, impacts of COVID-19 on toothache treatment, popular science articles of toothache), including 10 subcategories, to analyze the proportion of posts in each category. RESULTS: There were 12,603 postings closely related to toothache. Among them, 87.6% of posts did not indicate a specific cause of pain, and 92.8% of posts did not clearly indicate a specific method of treatment. There were 38.9% of the posts that clearly showed that their dental treatment of toothache was affected by COVID-19, including 10.5% of the posts in which patients were afraid to see the dentists because of COVID-19, and 28.4% of the posts in which patients were unable to see the dentists because the dental clinic was closed. Only 3.5% of all posts were about popular science of toothache. CONCLUSIONS: We have studied and analyzed social media data about toothache during the COVID-19 epidemic, so as to provide some insights for government organizations, the media and dentists to better guide the public to pay attention to oral health through social media. Research on social media data can help formulate public health policies.

A Statistical Study of the Correlation between Geomagnetic Storms and M ≥ 7.0 Global Earthquakes during 1957-2020.

In order to find out whether the geomagnetic storms and large-mega earthquakes are correlated or not, statistical studies based on Superposed Epoch Analysis (SEA), significance analysis, and Z test have been applied to the Dst index data and M ≥ 7.0 global earthquakes during 1957-2020. The results indicate that before M ≥ 7.0 global earthquakes, there are clearly higher probabilities of geomagnetic storms than after them. Geomagnetic storms are more likely to be related with shallow earthquakes rather than deep ones. Further statistical investigations of the results based on cumulative storm hours show consistency with those based on storm days, suggesting that the high probability of geomagnetic storms prior to large-mega earthquakes is significant and robust. Some possible mechanisms such as a reverse piezoelectric effect and/or electroosmotic flow are discussed to explain the statistical correlation. The result might open new perspectives in the complex process of earthquakes and the Lithosphere-Atmosphere-Ionosphere (LAI) coupling.

Inhibitory effects of resveratrol on orthodontic tooth movement and associated root resorption in rats.

OBJECTIVE: To investigate the effect of resveratrol (RSV) on orthodontic tooth movement (OTM) and orthodontic induced root resorption (OIRR) in rats. METHODS: Thirty-six male Wistar rats used in this study were randomly divided into three groups of 12 animals each. All test subjects underwent a 50 g orthodontic force each, generated from a nickel-titanium closed-coil spring. The control group were fed carboxymethylcellulose (CMC) while rats in other two groups were fed 5 mg/kg/d RSV or 10 mg/kg/d RSV (dissolved in CMC). After 14 days of OTM, all rats were sacrificed, after which each group was randomly divided into two subgroups (6 test subjects in each subgroup). One subgroup was used to measure the amount of OTM and assessed by hematoxylin and eosin (HE) staining, tartrate-resistant acid phosphatase (TRAP) staining, and immunohistochemistry staining of Receptor Activator of Nuclear Factor-κ B Ligand (RANKL), Osteoprotegerin (OPG), Runt-related transcription factor 2 (RUNX2), as well as Osteocalcin (OCN). The second subgroup was used to analyze OIRR via scanning electron microscopy. RESULTS: Compared with the control group, the RSV groups showed a significant decrease in the distance of OTM and the OIRR ratio (p＜0.05). The number of TRAP positive osteoclasts and the expression of RANKL in periodontal tissue of the RSV groups were significantly inhibited (p＜0.01) while the expression of OPG, RUNX2, and OCN were remarkably promoted (p＜0.05). The effect of 10 mg/kg/d RSV group was more obvious than that of 5 mg/kg/d RSV group (p＜0.05). CONCLUSIONS: RSV could reduce the extent of OTM and root resorption areas.

Functionalized Poly(arylene ether nitrile) Porous Membrane with High Pb(II) Adsorption Performance.

Porous materials with high specific surface area possess a broad application prospect in the treatment of wastewater. In this work, sulfonated poly(arylene ether nitrile) (SPEN) functionalized with a carboxylic acid group was successfully synthesized, which was subsequently transformed into SPEN porous membranes with cetyltrimethyl ammonium bromide (CTAB) as pore-forming agents to study the adsorption performance for lead ions in aqueous solution. Then, experiments were conducted to investigate the effect of pH, contact time and initial solution concentration on the adsorption performance of porous membranes, and the adsorption capacities of porous membranes with different content (0, 5 and 15 wt %) of CTAB were 183.60, 161.73 and 127.43 mg/g, respectively, which manifested that the adsorption capacity decreased with the increase of CTAB. The adsorption capacities of porous membranes increased with the increase of the initial concentration of lead ions, and the maximum reached was 246.96 mg/g. The simulation of adsorption kinetics revealed that the adsorption was accorded with the pseudo-second-order kinetic model and Langmuir equation, indicating that the adsorption process followed Langmuir monolayer adsorption. Thermogravimetric analysis demonstrated that the porous membranes had excellent thermodynamic properties both before and after adsorption. In addition, the change of adsorption peak in the Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (ATR-FTIR) spectrum indicated that the absorption performance of porous membranes for lead ions benefited from the chelation between lead ions and the carboxylic acid group on SPEN. Moreover, the porous membranes maintained excellent adsorption properties after circulating five times under the conditions of acidic or alkaline, and the cycle regeneration effect was outstanding.

[Effect of psoralen on the stability after orthodontic tooth movement in rats].

PURPOSE: This study was designed to investigate the effect of psoralen on periodontal tissue reconstruction after orthodontic tooth movement(OTM) in rats. METHODS: Thirty-six male 6-week-old Wistar rats were randomly divided into 2 groups: the experimental group and the control group. The experimental group and the control group were all installed between the central incisor and the left maxillary first molars to pull the first molars away from the force device; after 21 days, the force was removed and the rats in 2 groups were given drug gavage. Rats in the experimental group were given a gavage of psoralen 8 mg/kg per day, while rats in the control group were given the same amount of 0.9% sodium chloride everyday. Maxillary casts were made every week during the experimental and were scanned by 3D Scanner to measure relapse distance, and histologic examination was conducted. After 28 days, the rats were sacrificed and rats' upper jaw was separated. The remaining sections were immunohistochemically stained with BMP2 and BMP4. SPSS 19.0 software package was used for statistical analysis. RESULTS：Both groups had relapse after the force device was removed. Significant decrease of relapse percentage was observed in the experimental group compared with the control group at day 7，day 14，day 21 and day 28（P<0.05）. The speed of relapse of both groups were fastest in the first week and slowed down in the second, third and fourth week gradually. The speed of relapse in the experimental group in the first week was significantly less than in the control group(P<0.05).The expression of BMP2 and BMP4 within periodontal membrane and alveolar bone was significantly higher in the experimental group than in the control group(P<0.05). CONCLUSIONS: Psoralen can accelerate the reconstruction of periodontal tissues of orthodontic tooth and reduce relapse.

Complete mitochondrial genome of the red-spotted tokay gecko (Gekko gecko, Reptilia: Gekkonidae): comparison of red- and black-spotted tokay geckos.

Here, we sequenced the complete mitochondrial genome of the red-spotted tokay gecko (Squamata: Gekkonidae). The genome is 16,590 bp in size. Its gene arrangement pattern was identical with that of black-spotted tokay gecko. We compared the mitochondrial genome of red-spotted tokay gecko with that of the black-spotted tokay gecko. Nucleotide sequence of the two whole mitochondrial genomes was 97.99% similar, and the relatively high similarity seems to indicate that they may be separated at the subspecies level. The information of mitochondrial genome comparison of the two morphological types of tokay gecko is discussed in detail.