Search

One of the main illnesses that put people’s health in jeopardy is myocardial infarction (MI). After MI, damaged or dead cells set off an initial inflammatory response that thins the ventricle wall and degrades the extracellular matrix. At the same time, the ischemia and hypoxic conditions resulting from MI lead to significant capillary obstruction and rupture, impairing cardiac function and reducing blood flow to the heart. Therefore, attenuating the initial inflammatory response and promoting angiogenesis are very important for the treatment of MI. Here, to reduce inflammation and promote angiogenesis in infarcted area, we report a new kind of injectable hydrogel composed of puerarin and chitosan via in situ self-assembly with simultaneous delivery of mesoporous silica nanoparticles (CHP@Si) for myocardial repair. On the one hand, puerarin degraded from CHP@Si hydrogel modulated the inflammatory response via inhibiting M1-type polarization of macrophages and expression of pro-inflammatory factors. On the other hand, silica ions and puerarin released from CHP@Si hydrogel showed synergistic activity to improve the cell viability, migration and angiogenic gene expression of HUVECs in both conventional and oxygen/glucose-deprived environments. It suggests that this multifunctional injectable CHP@Si hydrogel with good biocompatibility may be an appropriate candidate as a bioactive material for myocardial repair post-MI.

Although titanium and its alloys are extensively used in orthopedics and dentistry fields, implant failures still happen because of implant-associated infections. Herein, Au@Ag@Pt core–shell nanorods with noble metal combination were fabricated and assembled on medical titanium surface and the antibacterial activity and biocompatibility were investigated. The results showed that antibacterial rates of Ti–Au@Ag@Pt against S. epidermidis and P. aeruginosa were 89.7% and 92.7%, respectively. Besides, Ti–Au@Ag@Pt showed no obvious cell toxicity with MC3T3-E1 cells grew well on the sample surface. It was discovered that the Pt shell layer on Ti–Au@Ag@Pt slowed down the Ag ion release rate which endowed medical titanium surface with both antibacterial activity and good biocompatibility.

A superlattice composite of Zn-Fe layered double hydroxide and graphene oxide was fabricated on the titanium surface and showed lamellar morphology. It was found for the first time that this superlattice composite could inhibit cell adhesion and proliferation, and cause cell death of the cholangiocarcinoma cell line RBE cells

Understanding the impacts of air pollution on public health and individual behavior is crucial for optimal environmental policy design. Using 2015 census microdata in China, this paper examined the causal effect of air pollution on working place choice. The research design relies on a regression discontinuity design based on China’s Huai River Policy. The discontinuity in air pollution caused by the Huai River Policy provides a natural experiment to estimate the impact of air pollution. The results show that air pollution significantly increases the possibility of individuals working near home. The positive effect of air pollution on working near home is more significant for women, the elderly, urban individuals and those individuals working in secondary and tertiary industries. This study improves our understanding of the health effects and avoidance behavior associated with environmental hazards, discusses the negative impact of air pollution on labor mobility and mismatch by making individuals work nearby, and emphasizes that strengthening air pollution control should be a long-term policy.

Graphene and its derivatives attract extensive research interests in the biomedicine field due to their outstanding physiochemical properties. Lots of studies have reported that graphene materials exhibit antibacterial activities. However, antibacterial mechanisms of graphene materials still remain controversial and need further investigation. Herein, graphene oxide (GO) with and without nitrogen-doping were fabricated on the titanium surface by cathodic electrophoretic deposition and antibacterial activities were systematically investigated. Results showed that GO on the titanium surface presented antibacterial activity, while nitrogen-doped GO lost the antibacterial activity. The reason is that antibacterial mechanisms for the GO-metal system contain two steps. First, electron transfer occurs from bacterium’s cell membrane to GO surface which destroys the bacterial respiratory chain; subsequently, electrons on GO surface induce the production of reactive oxygen species (ROS) that damage the membrane structure and eventually lead to bacterial death. For nitrogen-doped GO, nitrogen atoms denote electrons into GO leading to n-type doping. Nitrogen-doped GO as an electron donor cuts off the electron transfer from the cell membrane to GO and subsequently inhibits the production of ROS. This is why nitrogen-doped GO exhibits no antibacterial activity. This work confirms the antibacterial mechanisms for the GO-metal system with a synergistic effect of non-oxidative electron transfer and ROS mediated oxidative stress.

This study aims to determine the efficacy of Zinc finger protein ZBTB20 in treatment of post‐infarction cardiac remodelling. For this purpose, left anterior descending (LAD) ligation was operated on mice to induce myocardial infarction (MI) with sham control group as contrast and adeno‐associated virus (AAV9) system was used to deliver ZBTB20 to mouse heart by myocardial injection with vehicle‐injected control group as contrast two weeks before MI surgery. Then four weeks after MI, vehicle‐treated mice with left ventricular (LV) remodelling underwent deterioration of cardiac function, with symptoms of hypertrophy, interstitial fibrosis, inflammation and apoptosis. The vehicle‐injected mice also showed increase of infarct size and decrease of survival rate. Meanwhile, the ZBTB20‐overexpressed mice displayed improvement after MI. Moreover, the anti‐apoptosis effect of ZBTB20 was further confirmed in H9c2 cells subjected to hypoxia in vitro. Further study suggested that ZBTB20 exerts cardioprotection by inhibiting tumour necrosis factor α/apoptosis signal‐regulating kinase 1 (ASK1)/c‐Jun N‐terminal kinase 1/2 (JNK1/2) signalling, which was confirmed by shRNA‐JNK adenoviruses transfection or a JNK activator in vitro as well as ASK1 overexpression in vivo. In summary, our data suggest that ZBTB20 could alleviate cardiac remodelling post‐MI. Thus, administration of ZBTB20 can be considered as a promising treatment strategy for heart failure post‐MI. Significance Statement: ZBTB20 could alleviate cardiac remodelling post‐MI via inhibition of ASK1/JNK1/2 signalling.

Background: To analyze the distribution of Porphyromonas gingivalis (P. gingivalis) kgp genotype in subgingival plaque of patients with diabetic periodontitis. The genetic polymorphism of the kgp gene in diabetic periodontitis was explored, and the correlation between different genotypes and diabetic periodontitis was obtained. Methods: Subgingival plaque samples were collected from 49 patients with periodontitis (21 with diabetes, 28 with non-diabetic periodontitis) and 11 healthy periodontal subjects. DNA was extracted, and the positive samples of P. gingivalis were screened by PCR with specific primers of 16S rRNA gene of P. gingivalis, and the fragment of kgp catalytic domain was obtained by PCR with specific primers of kgp. The genotype of kgp was determined by Mse I digestion of the catalytic domain fragment of kgp, and the experimental data were analyzed by the Pearson χ2 method. Results: Among the 11 healthy periodontal population samples collected in this study, 4 cases (36.4 %) of P. gingivalis were detected. Among 49 subgingival plaque samples of periodontitis, 47 patients (95.9 %) were detected with P. gingivalis. There was a statistical difference between the two. Among the 47 samples with P. gingivalis, the detection rate of kgp I was 57.4 %, the detection rate of kgp II was 31.9 %, and the detection rate of kgp I + II was 10.6 %. The kgp genotype was not associated with diabetes. There was no significant difference in the kgp genotypes between the two groups with different PD depths. Conclusion: P. gingivalis is associated with periodontitis. P. gingivalis kgp gene polymorphism exists in patients with diabetic periodontitis subgingival plaque.

Objective. To study the preventive effect of Lactobacillus helveticus (L. helveticus) on periodontitis induced by Aggregatibacter actinomycetemcomitans (A. actinomycetemcomitans) in rats. Methods. Eighteen 8-week-old female rats were randomly divided into three groups: Sham group, Trehalose group, and L. helveticus SBT2171 (LH2171) group. We measured the distance of the cementoenamel junction-alveolar bone crest (CEJ-ABC) to evaluate alveolar bone resorption. Hematoxylin-eosin staining was used to observe the histopathological changes of rat hemimaxillary tissues. We detected the expression of β-defensins, tumor necrosis factor-α (TNF-α), interleukin- (IL-) 1β, and IL-6 and the number of A. actinomycetemcomitans in rat gingival tissues by quantitative reverse transcriptase polymerase chain reaction. The levels of IL-1β, IL-6, and TNF-α in rat gingival tissues were also measured by enzyme-linked immunosorbent assay. Results. Compared with the Trehalose group, the distance of CEJ-ABC was prominently reduced and alveolar bone resorption was notably improved in the LH2171 group. And the infiltration of inflammatory cells in the hemimaxillary tissue decreased obviously, periodontal fibers were arranged neatly, connective tissue small blood vessels proliferated, and the number of A. actinomycetemcomitans reduced significantly in the LH2171 group. In addition, the mRNA expression and release of inflammatory factors in the gingival tissues in the LH2171 group were notably lower than those in the Trehalose group. On the 21st and 36th day, the expression of β-defensins in the gingival tissue of the LH2171 group increased significantly. Conclusion. L. helveticus improves alveolar bone resorption and increases the expression of β-defensins thereby inhibiting the number of A. actinomycetemcomitans and thus prevents periodontitis.

Plants can produce reactive oxygen species (ROS) to counteract pathogen invasion, and pathogens have also evolved corresponding ROS scavenging strategies to promote infection and pathogenicity. Catalases (CATs) have been found to play pivotal roles in detoxifying H2O2 formed by superoxide anion catalyzed by superoxide dismutases (SODs). However, few studies have addressed H2O2 removing during rust fungi infection of wheat. In this study, we cloned a CAT gene PsCAT1 from Puccinia striiformis f. sp. tritici (Pst), which encodes a monofunctional heme-containing catalase. PsCAT1 exhibited a high degree of tolerance to pH and temperature, and forms high homopolymers.Heterologous complementation assays in Saccharomyces cerevisiae reveal that the signal peptide of PsCAT1 is functional. Overexpression of PsCAT1 enhanced S. cerevisiae resistance to H2O2. Transient expression of PsCAT1 in Nicotiana benthamiana suppressed Bax-induced cell death. Knockdown of PsCAT1 using a host-induced gene silencing (HIGS) system led to the reduced virulence of Pst, which was correlated to H2O2 accumulation in HIGS plants. These results indicate that PsCAT1 acts as an important pathogenicity factor that facilitates Pst infection by scavenging host-derived H2O2.

A new methacrylate monomer containing ferrocene unit and disulfide bond, 2-((2-(methacryloyloxy)ethyl)disulfanyl)ethyl ferrocenecarboxylate (FcMAss), was prepared by subsequent esterification reaction with bis(2-hydroxyethyl) disulfide and methacryloyl chloride using ferrocenecarboxylic acid as starting material. A series of well-defined poly(2-((2-(methacryloyloxy)ethyl)disulfanyl)ethyl ferrocenecarboxylate) (PFcMAss) homopolymers with narrow molecular weight distributions (Mw/Mn

Implant failures still happen because of bacterial infections and inferior osteogenic properties. Graphene oxide (GO) could induce osteogenic differentiation as well as exhibit superior antibacterial activity which may provide an answer for this issue. In this work, GO films loaded with minocycline hydrochloride (MH) were fabricated on titanium implant surfaces, and the antibacterial activity and osteogenic properties were studied in the presence of S. aureus and rat bone mesenchymal stem cells (rBMSCs) in in vitro and in vivo environments, respectively. The results indicated that the MH loaded GO films on titanium surfaces (MH&GO@Ti) exhibited enhanced osteogenic activity in vitro with improved alkaline phosphatase (ALP) activity and enhanced osteogenic related gene expressions including ALP, collagen-I, osteocalcin, and osteopontin. The in vitro results of the co-culture of rBMSCs and S. aureus indicated that the rBMSCs grew well on the MH&GO@Ti sample with a higher coverage of cells and the bacteria were almost unobservable on the surface. In the in vivo experiments, the MH&GO@Ti exhibited excellent antibacterial and osteogenic activities in the presence of bacteria. No inflammatory cells for example neutrophils were found and superior bone–implant integration was obtained. This study offers a new proposal for the clinical application of drug-loaded graphene coating.

The aim of this study was to identify the influencing factors of peri-implantitis for implant prosthesis and to establish a predictive model of occurrence in managing patients with chronic periodontitis. 430 patients (a total of 686 implants) with 5 years follow-up were included in the study. The demographic and clinical characteristics independent variables were including patient related factors (age, gender, duration of symptoms, smoking, diabetes, severity of periodontitis, bone mineral density, oral hygiene) and implants related factors (position, implant diameter, implant length, additional operations, probing depth, gingival index, plaque index, load-bearing time). Univariate analysis identified the influencing factors, the statistically significant factors were further analyzed by multivariate logistic regression, and the predictive model was established. After 5 years of follow-up, peri-implantitis occurred in 95 of 686 implants (13.8%). Multiple linear regression indicated that smoking (p = 0.011), diabetes (p 0.05) Logistic regression drew the equation: occurrence of peri-implantitis = [1 + e (16.172+5.395*smoking+4.807*diabetes +8.109*severe periodontitis+5.569*lager implant diameter+11.138*poor oral hygiene)]−1. The sensitivity of predictive factors was 91.77%, 88.43%, 82.64%, 85.21% and 92.02%, respectively. The specificity 45.65%, 49.17%, 66.23%, 42.39% and 65.41%, respectively. The AUC was 0.721, 0.620, 0.453, 0.651 and 0.826, respectively. Hosmer-Lemeshow test showed a good fitting of the predictive model with an overall accuracy of 87.2%. Smoking, diabetes, severe periodontitis, lager implant diameter and poor oral hygiene are important risk factors of peri-implantitis. We also established a novel and accurate predictive model for the occurrence of peri-implantitis in managing patients with chronic periodontitis. The use of these parameters, in the form of a predictive model, has the potential to improve decision-making in the application of the treatment plan.

Hydrogen peroxide (H2O2) is an important mediator in biological medicine, disease diagnosis and environmental analyses and therefore it is essential to develop a detection approach for H2O2 in physical environments. Herein, we designed and prepared a series of AuNP-containing nanocomposites (AuNPs@NGO-PEG, AuNPs@G1-PAMAM-NGO-PEG and AuNPs@G3-PAMAM-NGO-PEG) for enhanced non-enzymatic H2O2 detection. We firstly demonstrated functionalized nanographene oxide (NGO) based materials, which combined advantages of biocompatible poly(ethylene glycol) (PEG), hyperbranched polyamidamine (PAMAM) dendrimer and thiol active site, as compatible platforms. Gold nanoparticles (AuNPs) were then aptly in situ grown on these functionalized NGO based materials via the reduction of HAuCl4 under mild conditions, i.e. AuNPs@NGO-PEG, AuNPs@G1-PAMAM-NGO-PEG and AuNPs@G3-PAMAM-NGO-PEG nanocomposites, which possess stable and uniform AuNPs standing on the functionalized NGO sheets. For H2O2 detection, these nanocomposites were cast on a glassy carbon electrode (GCE) conveniently, i.e. GCE/AuNPs@NGO-PEG, GCE/AuNPs@G1-PAMAM-NGO-PEG and GCE/AuNPs@G3-PAMAM-NGO-PEG. It is evident that these GCEs could be applied as efficient non-enzymatic H2O2 detectors resulting from the corresponding cyclic voltammetric curves and typical ready-state amperometric curves. GCE/AuNPs@G1-PAMAM-NGO-PEG exhibited the fastest electron transfer rate among these modified GCEs. We envisage that these GCEs could provide efficient sensors for H2O2 detection and a new strategy for sensor design.

Background To evaluate the associations of impaction patterns of mandibular third molars (M3Ms) with pathologies caused by them. Methods In this study, 262 patients with 432 impacted M3Ms were included. The pathologies include pericoronitis, mandibular second molar (M2M) caries, and M2M distal periodontal pathology. The impaction patterns of M3Ms and the pathologies were examined, and the M2Ms outcomes after the surgeries were evaluated. χ2 test was used to analyze the data and a P value of

Excellent antibacterial property of graphene oxide makes it an important antibacterial material. However, in some cases, a synergistic combination of materials with different antibacterial mechanisms is desired. In this work, we developed a simple two-step protocol to prepare ornidazole (ONZ), a nitroimidazole antiprotozoal drug, loaded graphene-based paper for combined antibacterial materials. Graphene oxide (GO) and reduced graphene oxide (rGO) were used as carriers in antibacterial materials. After mixed with ONZ directly in aqueous media and filtrated under vacuum, the freestanding GO/ONZ and rGO/ONZ were peeled off from the filtrate membrane. The ONZ loading contents in the paper was determined by UV/vis spectroscopy and the surface properties were investigated by measuring their contact angle, which will have an important impact on the antibacterial effects of the papers. Keywords: Ornidazole, Graphene oxide, Antibacterial material

To investigate protein-resistant surfaces with heterogeneous nanopatterns, V-shaped polymer brushes composed of a hydrophilic methoxypoly(ethylene glycol) (mPEG) arm and a hydrophobic polystyrene (PS) or fluorinated poly(methyl methacrylate) (PMMA-b-PFMA) arm were prepared, in which the surface structure and phase-separation behavior were controlled by altering the relative lengths of the two arms. The protein resistance of these amphiphilic brushes was better than that of pure poly(ethylene glycol) (PEG) brushes, and when the domain size of the phase-separated structures was about twice the size of the protein molecules, the surfaces exhibited optimal protein repellence. At the same time, the amount of protein adsorption was well related to both the adhesion and the relative friction coefficient of the protein on the brush surface. A heterogeneous surface with phase-separated domains twice the size of protein molecules may be beneficial for minimizing protein adsorption through the synergistic effect of ...

Thin polymer films with well-assembled fluorinated groups on their surfaces are not easily achieved via spin-coating film-fabrication methods because the solution solidifies very rapidly during spin-coating, which hinders the fluorinated moieties from segregating and organizing on the film surface. In this contribution, we have proposed a comprehensive strategy toward achieving well-ordered fluorinated thin films surfaces by optimizing the molecular organization at air/liquid interface of the film-formation solutions. To validate such a route, poly(methyl methacrylate) (PMMA) end-capped with several 2-perfluorooctylethyl methacrylate (FMA) units was employed as the model polymer for investigations. The air/solution interfacial structures were optimized by systematically changing the polymer chain structures and properties of the casting solvents. It was found that the polymers that form loosely associated aggregates (e.g., FMA1- ec-PMMA65- ec-FMA1) and a solvent with better solubility to FMA while having not too low surface tension (i.e., toluene) can combine to produce solutions with well-assembled FMA at the interfaces. By spin-coating the solutions with well-organized interfaces, an ultrathin film with perfluorinated groups that were highly oriented toward the film surface was readily achieved, exhibiting surface energies as low as 7.2 mJ/m2, which is among the lowest reported so far for the spin-coated thin films, and a very high F/C ratio (i.e., 0.98).

Titanium and its alloys have been widely used in orthopedic and dental implants because of their excellent properties. However, implant failures still occur due to implant-associated bacterial infections. Therefore, proper surface modification of titanium and its alloys is necessary. In this work, commercial pure titanium plates were modified with graphene oxide (GO) which was used to load minocycline hydrochloride. Gram-positive Staphylococcus aureus (S. aureus) and Streptococcus mutans (S. mutans) and Gram-negative Escherichia coli (E. coli) were used to investigate the antibacterial activity of the samples. Human gingival fibroblast (HGF) cells were applied to assess the cytocompatibility of the various samples. To investigate cell adhesion and cell surface coverage in the presence of bacteria, the coculture of HGF cells and S. aureus was performed. The results indicated that the GO-modified titanium surface could inhibit the growth of the bacteria which had direct contact with GO, while it could not affect the bacteria without direct contact of GO. Minocycline hydrochloride on the GO-modified titanium surface (M@GO-Ti) showed a slow release behavior and exhibited excellent antibacterial activity with the synergistic effect of contact-killing and release-killing by GO and minocycline hydrochloride, respectively. In the coculture process with the presence of S. aureus, HGF cells on M@GO-Ti demonstrated the best cell viability and cell surface coverage among all the samples.

Currently, graphene and its derivatives, used for surface modification of orthopedic and dental implants, are mainly in the form of two-dimensional planar structure. There is little information of three dimensional porous graphene nanosheets used as coating materials of titanium and its alloys. In the present study, three dimensional porous graphene nanosheets were first synthesized on the pure titanium surface. The physicochemical properties and osteogenic activity of the three dimensional porous graphene nanosheets-modified titanium (rGO@Ti) were systematically investigated. The results suggested that rGO@Ti showed super hydrophilicity, rough surface and excellent biocompatibility, and could enhance alkaline phosphatase (ALP) activity, extracellular matrix (ECM) mineralization and collagen secretion of rat bone mesenchymal stem cells (rBMSCs). Meanwhile, the expressions of osteogenesis related genes containing ALP, bone morphogenic protein-2 (BMP-2), osteocalcin (OCN), and osteopontin (OPN) on rGO@Ti were improved. The osteogenic differentiation of rBMSCs on rGO@Ti may be ascribed to both its superior protein adsorption ability and physical stimulation induced by the unique structure of three dimensional porous graphene nanosheets.

Polymer monolayers at liquid surfaces have attracted considerable attention as tools to construct molecular devices with unique properties. The aggregation states of chains within the monolayers must be understood as the first benchmark to establish molecular designs for the devices. It has been reported that large differences exist in surface pressure–area isotherms of polyacrylates and polymethacrylates at the water surface, although they differ chemically only by the absence of an alpha methyl group (α-CH3) in the former. Herein, we carried out experiments using sum-frequency generation vibrational spectroscopy, atomic force microscopy and infrared reflection absorption spectroscopy to explore the changes of the aggregation state and interaction of four poly(acrylates) (i.e., poly(methyl acrylate), PMA; poly(ethyl acrylate), PEA; poly(methyl methacrylate), PMMA; poly(ethyl methacrylate), PEMA) at the water surface during compression. In the case of PMA and PEA without α-CH3, the polymer chains adopt an...

Graphene oxide has attracted widespread attention in the biomedical fields due to its excellent biocompatibility. Herein we investigated the layer-number dependent antibacterial and osteogenic behaviors of graphene oxide in biointerfaces. Graphene oxide with different layer numbers was deposited on the titanium surfaces by cathodal electrophoretic deposition with varied deposition voltages. The initial cell adhesion and spreading, cell proliferation, and osteogenic differentiation were observed from all the samples using rat bone mesenchymal stem cells. Both Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus were used to investigate the antibacterial effect of the modified titanium surfaces. Cocultures of human gingival fibroblasts (HGF) cells with Escherichia coli and Staphylococcus aureus were conducted to simulate the conditions of the clinical practice. The results show that the titanium surfaces with graphene oxide exhibited excellent antibacterial and osteogenic effects. Increasing the layer-number of graphene oxide resulted in the augment of reactive oxygen species levels and the wrinkling, which led to the antibacterial and osteogenic effects, respectively. Compared to pure titanium surface in the cells-bacteria coculture process, the modified titanium surfaces with graphene oxide exhibited higher surface coverage percentage of cells.

A well-defined amphiphilic graft copolymer comprising a hydrophilic poly(acrylic acid) (PAA) backbone and hydrophobic poly(lactic acid) side chains was synthesized by a combination of reversible addition–fragmentation chain transfer (RAFT) polymerization, ring open polymerization (ROP), and the grafting-from strategy. A well-defined PtBHBMA homopolymer having pendant hydroxyls in every repeated unit was first obtained by RAFT homopolymerization of a OH-containing tert-butyl 2-((4-hydroxybutanoyloxy)methyl)acrylate (tBHBMA) monomer. ROP of lactide was directly initiated by the pendant hydroxyls of PtBHBMA to provide a well-defined poly(tert-butyl acrylate)-g-poly(lactic acid) (PtBA-g-PLA) graft copolymer via the grafting-from strategy without post-polymerization functionality transformation. The hydrophobic PtBA backbone was selectively hydrolyzed into the hydrophilic PAA backbone so as to afford the targeted well-defined PAA-g-PLA amphiphilic graft copolymer (Mw/Mn = 1.17) having equally-distributed carboxyls along the backbone. PAA-g-PLA amphiphilic graft copolymer shows pH-responsive micellization behavior and it can self-assemble into spheres under certain conditions. Doxorubicin (DOX) can be loaded by non-toxic micelles self-assembled by the PAA-g-PLA graft copolymer and its in vitro accumulative release characteristics were investigated by fluorescence spectroscopy. In comparison with free DOX, the DOX-loading nanoparticles display decreased cytotoxicity against SMMC-7721 and SH-SY5Y cells in 48 h because of a sustained release profile of DOX.

Dental health is associated with the growth and development, physical or psychological, of children. Although numerous preventive measures are available, dental caries among primary schoolchildren remains a public health concern in China. Understanding the disparity of children's dental health between rural and urban areas in China could provide further insight into the prevention of caries.A cross-sectional study was conducted to examine the oral health of pupils aged 6-12 years in Pudong District (Shanghai) and Lichuan (Jiangxi Province) in China. A questionnaire survey was performed among children's guardians to identify the potential risk factors for childhood dental caries.A total of 1922 primary schoolchildren were included in this study, with 815 from Pudong and 1107 from Lichuan. The mean age of children from Pudong was 8.57 (SD = 1.61), which was statistically significantly lower than their counterpart from Lichuan (9.36 ± 1.75). The prevalence of caries in Pudong and Lichuan was 63.4% and 75.0%, respectively. Statistically significant differences of demographical and behavioural features were observed between schoolchildren in Pudong and Lichuan. In general, Lichuan children had a higher caries risk compared with their Pudong counterparts (OR = 3.43, 95%CI 2.65-4.28). Moreover, the non-parental caregivers, low family income, low parental educational level, as well as bad dietary habits, were identified as risk factors for caries.Childhood caries in the rural area was far more severe than that in the urban area. This disparity was determined by several factors such as the high proportion of left-behind children in the rural area (e.g. children who remain in rural regions of China while their parents leave to work in urban areas). Our government should put the prevention of caries among rural children at a higher priority in the near future to narrow the gap between rural and urban areas.

Biotrophic pathogens, such as wheat rust fungi, survive on nutrients derived from host cells. Sugar appears to be the major carbon source transferred from host cells to various fungal pathogens; however, the molecular mechanism by which host sugar transporters are manipulated by fungal pathogens for nutrient uptake is poorly understood. TaSTP6, a sugar transporter protein in wheat (Triticum aestivum), was previously shown to exhibit enhanced expression in leaves upon infection by Puccinia striiformis f. sp. tritici (Pst), the causal agent of wheat stripe rust. In this study, we found that Pst infection caused increased accumulation of abscisic acid (ABA) and that application of exogenous ABA significantly enhanced TaSTP6 expression. Moreover, knockdown of TaSTP6 expression by barley stripe mosaic virus-induced gene silencing reduced wheat susceptibility to the Pst pathotype CYR31, suggesting that TaSTP6 expression upregulation contributes to Pst host sugar acquisition. Consistent with this, TaSTP6 overexpression in Arabidopsis (Arabidopsis thaliana) promoted plant susceptibility to powdery mildew and led to increased Glc accumulation in the leaves. Functional complementation assays in Saccharomyces cerevisiae showed that TaSTP6 has broad substrate specificity, indicating that TaSTP6 is an active sugar transporter. Subcellular localization analysis indicated that TaSTP6 localizes to the plasma membrane. Yeast two-hybrid and bimolecular fluorescence complementation experiments revealed that TaSTP6 undergoes oligomerization. Taken together, our results suggest that Pst stimulates ABA biosynthesis in host cells and thereby upregulates TaSTP6 expression, which increases sugar supply and promotes fungal infection.

Background Dental implant failures still occur because of peri-implant diseases such as peri-implantitis. The objective of this study was to treat peri-implantitis in beagle dogs by fabricating minocycline hydrochloride (MH)-loaded graphene oxide (GO) films on implant abutment surfaces. Methods Beagle dogs with silk ligature were used to establish the peri-implantitis model. Modified sulcus bleeding index, peri-implant probing pocket depth, radiographic evaluation, micro-CT tomography analysis, and histological evaluation were determined to evaluate the therapeutic effect of MH-loaded GO films on abutment surfaces for peri-implantitis. Results Radiographic and micro-CT analysis showed that lots of marginal bone loss could be found on Ti and MH/Ti groups, especially for Ti group. Little bone less could be seen on GO/Ti group while bone less on MH/GO/Ti group was negligible. Results of the histological analysis presented that lots of neutrophils could be found on Ti and MH/Ti groups. However, almost none of the neutrophils could be observed on GO/Ti and MH/GO/Ti while lots of osteocytes could be found. Conclusion MH-loaded GO films on implant abutment surfaces could prevent the further development of peri-implantitis and exhibit good therapeutic effect for peri-implantitis in beagle dogs.

Background Apical periodontitis (AP) is essentially an inflammatory disease of microbial etiology primarily caused by infection of the pulp and root canal system. Variation of the bacterial communities caused by AP, as well as their changes responding to dental therapy, are of utmost importance to understand the pathogensis of the apical periodontitis and establishing effective antimicrobial therapeutic strategies. This study aims to uncover the composition and diversity of microbiota associated to the root apex to identify the relevant bacteria highly involved in AP, with the consideration of root apex samples from the infected teeth (with/without root canal treatment), healthy teeth as well as the healthy oral. Methods Four groups of specimens are considered, the apical part of root from diseased teeth with and without root canal treatment, and wisdom teeth extracted to avoid being impacted (tooth healthy control), as well as an additional healthy oral control from biofilm of the buccal mucosa. DNA was extracted from these specimens and the microbiome was examined through focusing on the V3-V4 hypervariable region of the 16S rRNA gene using sequencing on Illumina MiSeq platform. Composition and diversity of the bacterial community were tested for individual samples, and between-group comparisons were done through differential analysis to identify the significant changes. Results We observed reduced community richness and diversity in microbiota samples from diseased teeth compared to healthy controls. Through differential analysis between AP teeth and healthy teeth, we identified 49 OTUs significantly down-regulated as well as 40 up-regulated OTUs for AP. Conclusion This study provides a global view of the microbial community of the AP associated cohorts, and revealed that AP involved not only bacteria accumulated with a high abundance, but also those significantly reduced ones due to microbial infection. Electronic supplementary material The online version of this article (10.1186/s12864-019-5474-y) contains supplementary material, which is available to authorized users.