Weighted Gene Co-expression Network Analysis and Machine Learning Validation for Identifying Major Genes Related to Sjogren's Syndrome.

Sjogren's syndrome (SS) is an autoimmune disorder characterized by dry mouth and dry eyes. Its pathogenic mechanism is currently unclear. This study aims to integrate weighted gene co-expression network analysis (WGCNA) and machine learning to identify key genes associated with SS. We downloaded 3 publicly available datasets from the GEO database comprising the gene expression data of 231 SS and 78 control cases, including GSE84844, GSE48378 and GSE51092, and carried out WGCNA to elucidate differences in the abundant genes. Candidate biomarkers for SS were then identified using a LASSO regression model. Totally 6 machine-learning models were subsequently utilized for validating the biological significance of major genes according to their expression. Finally, immune cell infiltration of the SS tissue was assessed using the CIBERSORT algorithm. A weighted gene co-expression network was built to divide genes into 10 modules. Among them, blue and red modules were most closely associated with SS, and showed significant enrichment in type I interferon signaling, cellular response to type I interferon and response to virus, etc. Combined machine learning identified 5 hub genes, including OAS1, EIF2AK2, IFITM3, TOP2A and STAT1. Immune cell infiltration analysis showed that SS was associated with CD8+ T cell, CD4+ T cell, gamma delta T cell, NK cell and dendritic cell activation. WGCNA was combined with machine learning to uncover genes that may be involved in SS pathogenesis, which can be utilized for developing SS biomarkers and appropriate therapeutic targets.

Exosome-liposome hybrid nanoparticle codelivery of TP and miR497 conspicuously overcomes chemoresistant ovarian cancer.

BACKGROUND: Although cisplatin-based chemotherapy has been used as the first-line treatment for ovarian cancer (OC), tumor cells develop resistance to cisplatin during treatment, causing poor prognosis in OC patients. Studies have demonstrated that overactivation of the phosphatidylinositol 3-kinase/protein kinase B/mammalian target of rapamycin (PI3K/AKT/mTOR) pathway is involved in tumor chemoresistance and that overexpression of microRNA-497 (miR497) may overcome OC chemotherapy resistance by inhibiting the mTOR pathway. However, the low transcriptional efficiency and unstable chemical properties of miR497 limit its clinical application. Additionally, triptolide (TP) was confirmed to possess a superior killing effect on cisplatin-resistant cell lines, partially through inhibiting the mTOR pathway. Even so, the clinical applications of TP are restricted by serious systemic toxicity and weak water solubility. RESULTS: Herein, whether the combined application of miR497 and TP could further overcome OC chemoresistance by synergically suppressing the mTOR signaling pathway was investigated. Bioinspired hybrid nanoparticles formed by the fusion of CD47-expressing tumor exosomes and cRGD-modified liposomes (miR497/TP-HENPs) were prepared to codeliver miR497 and TP. In vitro results indicated that the nanoparticles were efficiently taken up by tumor cells, thus significantly enhancing tumor cell apoptosis. Similarly, the hybrid nanoparticles were effectively enriched in the tumor areas and exerted significant anticancer activity without any negative effects in vivo. Mechanistically, they promoted dephosphorylation of the overactivated PI3K/AKT/mTOR signaling pathway, boosted reactive oxygen species (ROS) generation and upregulated the polarization of macrophages from M2 to M1 macrophages. CONCLUSION: Overall, our findings may provide a translational strategy to overcome cisplatin-resistant OC and offer a potential solution for the treatment of other cisplatin-resistant tumors.

Screening, cloning, enzymatic properties of a novel thermostable cellulase enzyme, and its potential application on water hyacinth utilization.

Cellulose is the cheapest, natural, renewable organic substance that is used as a carbon source in various fields. Water hyacinth, an aquatic plant rich in cellulose, is often used as a raw material in fuel production. However, natural cellulase can be hardly used in industrial production on account of its low thermal stability and activity. In this study, a metagenomic library was constructed. Then, a new cellulase gene, cel1029, was screened by Congo red staining and expressed in the prokaryotic system. Enzymatic properties of Cel1029 were explored, including optimum temperature and pH, thermal and pH stability, and tolerance against organic solvents, metal ions, and salt solutions. Finally, its ability of degrading water hyacinth was identified and evaluated. Cel1029 displayed high homology with endoglucanase in the glycoside hydrolase family 5 (GH5) and had high stability across a broad temperature range. More than 86% of its enzymatic activities were retained between 4 and 60 °C after 24 h of incubation. Single-factor analysis and orthogonal design were further conducted to determine the optimal conditions for the highest reducing sugar yield of water hyacinth. Interestingly, Cel1029 efficiently transformed water hyacinth with a reducing sugar yield of 430.39 mg/g in 22 h. These findings may open the door for significant industrial applications of a novel GH5 cellulase (NCBI Reference Sequence: MK051001, Cel1029) and help identify more efficient methods to degrade cellulose-rich plants.

Inhibition of bacterial growth on zirconia abutment with a helium cold atmospheric plasma jet treatment.

OBJECTIVES: This study presents a surface modification method to treat the zirconia implant abutment materials using a helium cold atmospheric plasma (CAP) jet in order to evaluate its efficacy on oral bacteria adhesion and growth. MATERIALS AND METHODS: Yttrium-Stabilized Zirconia disks were subjected to helium CAP treatment; after the treatment, zirconia surface was evaluated using scanning electron microscopy, a contact angle measuring device, X-ray photoelectron spectroscopy for surface characteristics. The response of Streptococcus mutans and Porphyromonas gingivalis on treated surface was evaluated by a scanning electron microscopy, MTT assay, and LIVE/DEAD staining. The biofilm formation was analyzed using a crystal violet assay. RESULTS: After the helium CAP jet treatment, the zirconia surface chemistry has been changed while the surface topography remains unchanged, the bacterial growth was inhibited, and the biofilm forming decreased. As the treatment time increases, the zirconia abutment showed a better bacterial inhibition efficacy. CONCLUSIONS: The helium CAP jet surface modification approach can eliminate bacterial growth on zirconia surface with surface chemistry change, while surface topography remained. CLINICAL RELEVANCE: Soft tissue seal around dental implant abutment plays a crucial role in maintaining long-term success. However, it is weaker than periodontal barriers and vulnerable to bacterial invasion. CAP has a potential prospect for improving soft tissue seal around the zirconia abutment, therefore providing better esthetics and most of all, prevent peri-implant lesions from happening.

Stable and Photothermally Efficient Antibody-Covered Cu3(PO4)2@Polydopamine Nanocomposites for Sensitive and Cost-Effective Immunoassays.

Polydopamine (PDA)-coated or encapsulating Cu3(PO4)2 (Cu3(PO4)2@PDA) nanosheets were synthesized, allowing the C-reaction protein (CRP) antibody to be attached electrostatically for immunosensing of CRP with simple photothermal detection. The antibody-covered Cu3(PO4)2@PDA nanosheets replace the antibody-conjugated enzyme in the enzyme-linked immunosorbant assays. Owing to the high surface area of the 2-D-structured Cu3(PO4)2@PDA nanosheets and the coabsorption of light in the near-IR spectrum by Cu3(PO4)2 and PDA, a small amount of Cu3(PO4)2@PDA confined in the wells of a titer plate generates an easily detectable temperature change after irradiation at 808 nm. The temperature changes, measured by an inexpensive pen-type thermometer, increased linearly with the analyte concentration from 0.42 to 16 pM. We found that the linear relationship can be fitted by the isotherm derived from responses collected from heterogeneous sensors covered with different ligand or antibody densities. The low detection limit (0.11 pM) is largely due to the attachment of a great number of antibodies onto the flat nanosheets. The antibody-covered Cu3(PO4)2@PDA nanosheets are stable and can be used under conditions that are generally unfavorable to enzymatic activities. The excellent agreement between our results and immunoturbidimetric assays of CRP in serum samples from patients and healthy donors demonstrates its utility for disease diagnosis in clinical settings. This cost-effective, biocompatible, and convenient photothermal immunosensor affords a range of possibilities for detecting diverse protein biomarkers.

MicroRNA let-7c-5p promotes osteogenic differentiation of dental pulp stem cells by inhibiting lipopolysaccharide-induced inflammation via HMGA2/PI3K/Akt signal blockade.

Pulpitis suppressed the level of let-7c-5p that promotes osteogenesis and bone formation by repressing HMGA2. In the current study, the function of let-7c-5p in the inflammation and osteogenesis in dental pulp stem cells (DPSCs) was explored. The level of let-7c-5p in DPSCs was up-regulated, and the cells were subjected to lipopolysaccharide (LPS) to induce inflammation. The effect of let-7c-5p on cell proliferation potential, osteogenic differentiation potential, and activity of HMGA2/PI3K/Akt pathway was detected. The administration of LPS suppressed the cell proliferation of DPSCs and suppressed calcium deposition, activity of alkaline phosphatase (ALP), and levels of OCN, OPN, OSX, MSX2, and RUNX2 in inflamed DPSCs. The impaired osteogenic differentiation of inflamed DPSCs was associated with the increased levels of HMGA2, p-PI3K, and p-Akt. In let-7c-5p-overexpressed inflamed DPSCs, the proliferation and osteogenic differentiation potential of DPSCs were restored, and the activation of HMGA2/PI3K/Akt signalling was inhibited. In rat pulpitis models, the injection of let-7c-5p agomir restored the osteogenic differentiation potential of dental pulp cells and inhibited HMGA2/PI3K/Akt signalling. The findings demonstrated the anti-inflammation and pro-osteogenesis effect of let-7c-5p during the attack of pulpitis, which depended on the inhibition of HMGA2/PI3K/Akt signalling.

MicroRNA let-7c-5p Suppressed Lipopolysaccharide-Induced Dental Pulp Inflammation by Inhibiting Dentin Matrix Protein-1-Mediated Nuclear Factor kappa B (NF-κB) Pathway In Vitro and In Vivo.

BACKGROUND Let-7c-5p is down-regulated in dental pulp tissues in inflammatory disorders. The microRNA (miR) molecule shows an anti-inflammation potential due to its direct regulation of dentin matrix protein-1 (DMP1), which promotes inflammation changes in dental pulp tissues. In the present study, the effect of let-7c-5p on lipopolysaccharide (LPS)-induced pulpitis was detected and the associated mechanism was explored. MATERIAL AND METHODS Dental pulp stem cells (DPSCs) were isolated from rat dental tissues, infected with let-7c-5p lentivirus particles, and subjected to LPS administration to induce inflammation. Then, the effect of let-7c-5p overexpression on LPS-induced impairments on DPSCs were detected and the mechanism was explained by focusing on the DMP1 expression and NF-κB pathway. The role of DMP1 in the anti-inflammation effect of let-7c-5p was assessed by incubating let-7c-5p-expressed DPSCs with DMP1 protein. The results of in vitro assays were verified in LPS-induced rat pulpitis models. RESULTS LPS administration increased the production of IL-1ß and TNF-α and decreased DPSCs viability by increasing the expression of DMP1 and activating NF-κB pathway. However, the induced expression of let-7c-5p relieved DPSCs from LPS-induced inflammation and suppressed DMP1 as well as NF-κB pathway. The incubation of let-7c-5p-expressed DPSCs with DMP1 protein blocked the effect of let-7c-5p. In in vivo experiments, the injection of let-7c-5p attenuated LPS-induced pulpitis by inhibiting DMP1-mediated NF-κB pathway. CONCLUSIONS Findings outlined in the current study demonstrated the dental pulp protecting function of let-7c-5p during LPS-induced inflammation, which was exerted by inhibiting the DMP1-mediated NF-κB pathway.

Neuro-Magnetic Resonance Imaging in Hand, Foot, and Mouth Disease: Finding in 412 Patients and Prognostic Features.

PURPOSE: The aims of this study were to describe the neuroimaging findings in hand, foot, and mouth disease and determine those who may provide prognosis. MATERIAL AND METHODS: Magnetic resonance imaging scans in 412 severe hand, foot, and mouth disease between 2009 and 2014 were retrospectively evaluated. The patients who had the neurological signs were followed for 6 months to 1 year. According to the good or poor prognosis, 2 groups were categorized. The incidence of lesions in different sites between the 2 groups was compared, and multivariate analysis was used to look for risk factors. RESULTS: The major sites of involvement for all patients with percentages were the medulla oblongata (16.1%), spinal anterior nerve roots (12.4%), thoracic segments (11.1%), brain or spinal meninges (8.3%), and so on. There were 347 patients (84.2%) with good prognosis and 65 (15.8%) with poor prognosis in the follow-up. There was a significantly higher rate of lesions involving the cerebral white substance, thalamus, medulla oblongata, pons, midbrain, and spinal cord in the group with poor prognosis. Multivariate analysis showed 2 independent risk factors associated with poor prognosis: lesions located in the medulla oblongata (P < 0.015) and spinal cord (P < 0.001) on magnetic resonance imaging; the latter was the most significant prognostic factor (odds ratio, 29.11; P < 0.001). CONCLUSIONS: We found that the distribution patterns for all patients mainly involved the medulla oblongata, spinal anterior nerve roots, thoracic segments, and brain or spinal meninges. Our findings suggested that patients with lesions located in the medulla oblongata and spinal cord may be closely monitored for early intervention and meticulous management. For children with the symptom of nervous system, they are strongly recommended for magnetic resonance examination.

Optic replacement in a novel modular intraocular lens system.

PURPOSE: The purpose of the study is to evaluate the stability and ease of replacement of a new modular intraocular lens (IOL) system consisting of a hydrophobic acrylic base unit and a hydrophobic acrylic optic in the rabbit model. METHODS: Five New Zealand white rabbits were utilized. Bilateral phacoemulsification was performed; one eye received the test IOL (ClarVista Harmoni Modular IOL System) and the other, a commercially available hydrophobic acrylic control IOL (Alcon AcrySof SA60AT). Slit-lamp examinations were performed weekly during postoperative weeks 1 to 6. IOL replacement procedures were performed at weeks 2 and 6 using standard instruments. The rabbits were sacrificed at the end of the study (week 6), with all globes analyzed grossly using the Miyake-Apple technique and sectioned and processed for histopathologic examination. RESULTS: The base component and the optic of the Harmoni IOL system remained stable and centred throughout the clinical follow up. Disengagement of the optic component from the base and replacement of the optic were safely and easily accomplished at 2 and 6 weeks postoperatively. Explantation of the control lens required posterior synechiolysis and capsular bag manipulation due to the position of the loops at the periphery of the bag, thus causing zonular stress. CONCLUSIONS: Replacement of the Harmoni optic was found to be safe and efficient compared with the control IOL, as manipulation of the capsular bag to remove haptic components is not necessary with the modular design. The base component of the modular system remained stable and centred throughout the study.

[The swelling behavior of choline fenofibrate hydrogel matrix tablets using dynamic image analysis].

The purpose of this study is to investigate the effects of formulation on the swelling behavior of choline fenofibrate hydrogel matrix tablets and reveal the relation between swelling property and release profile using dynamic image analysis. The volume swelling ratio (SR) and height/width (k) could evaluate the swelling behavior of matrix tablets well. The mount of hydroxypropyl methylcellulose (HPMC) and the ratio between K15M and K4M affected the volume swelling ratio, while PVP didn't. The three factors all impacted k, which was an indicator of the strength of the gel formed by HPMC. The accumulative release ratio and SR, the rate of swelling and the rate of release were compared. The proper model equations were established for the results with an excellent correlation. The results prove that there is a strong relevance between the swelling behavior and release property. This study provides a guideline in the study design for hydrogel matrix tablets.

[Preparation and properties of thermosensitive in situ gel for ophthalmic formulation containing pearl hydrolyzate].

The study was designed to generate an ophthalmic thermosensitive in situ gel with improved mechanical and mucoadhesive properties that may prolong the retention time to enhance the bioavalability of pearl hydrolyzate. The gene was comprised of poloxamer 407, poloxamer188 and Carbopol 934, which were optimized by central composite design and response surface methodology. The rheological properties, transcorneal permeability, retention time and in vitro release behaviors of the optimal gel formulation were investigated. The gel was Newtonian liquid at 25 ℃ and performed as a semisolid gel with non-Newtonian liquid property with a gelation time of 13 s at 35 ℃. Compared with a conventional eye drops, the ophthalmic in situ gel exhibited a sevenfold increase in retention with a sustained release behavior, which was observed with suitable permeability coefficient at 5.58 cm·s-1. In conclusion, the new gel of pearl hydrolyzate prolonged the release duration of drug, which may decrease the frequency of administration of pearl hydrolyzate.

[The rheology properties of common hydrophilic gel excipients].

To investigate theological properties of common hydrophilic gel excipients such as Carbopol based on viscosity, the viscosity was determined by rotation method and falling-ball method. Linear regression was made between ln(eta) and concentration, the slope of which was used to explore the relation between viscosity and concentration of different excipients. The viscosity flow active energy (E(eta)) was calculated according to Arrhenius equation and was used to investigate the relation between viscosity and temperature of different excipients. The results showed that viscosities measured by two methods were consistent. Concentration of guargum (GG) and hydroxypropylmethyl cellulose (HPMC) solution had a great influence on the viscosity, k > 5; while concentration of polyvinylpyrrolidone-K30 (PVP-K30) and polyethylene glycol 6000 (PEG6000) exerted a less effect on viscosity, k < 0.2; viscosity flow active energy of different excipients were close, which ranged from 30 to 40 kJ x mol(-1). Therefore, theological properties study could provide the basis for application of excipients and establish a foundation for the research of relation between excipients structure, property and function.

Investigation on the improvement of mechanical properties and surface quality of the polylactic acid (PLA) fused filament fabrication parts manufactured without and with vibrations dependent utilization.

Fused Filament Fabrication (FFF), is one of the most widely used additive manufacturing technologies today, which has been used for a variety of applications. Due to the layer-by-layer manufacturing process, FFF parts are inferior to those fabricated by traditional methods in terms of tensile properties, which is one of the most significant defects that hinder the development of this technique. In this study, a vibration was utilized during the FFF process by piezoelectric ceramics electric plates to improve the mechanical properties of the built parts and surface quality of PLA FFF parts. Subsequently, an investigation of the tensile and the surface quality of PLA FFF specimens built-in X and Z-direction fabricated individually without and with vibrations utilized has been done. Furthermore, a theoretical model has been established to predict the tensile strength and plasticity of FFF parts fabricated without and with vibrations utilized based on classical laminated plate theory, with the anisotropic and laminated characteristics taken into consideration. Young's modulus model has been established based on the laminated plate theory and flexural vibration theoretical approaches of a plate for the PLA FFF parts manufactured without and with vibrations utilized respectively. Compared with the previous models this model provides the tensile strength and plasticity of FFF parts both manufactured without and with vibrations utilized. The results indicate that the predicted tensile strength and plasticity of the PLA FFF parts manufactured with vibrations utilized have a good consistency with the experimental ones, meanwhile, vibration utilization can significantly improve the surface quality of the PLA FFF samples manufactured in the Z-direction, and the scanning electron microscopy (SEM) analysis confirmed that vibration utilization can improve the forming quality of FFF manufactured parts.

Single-cell analysis of immune cells on gingiva-derived mesenchymal stem cells in experimental autoimmune uveitis.

Gingiva-derived mesenchymal stem cells (GMSCs) have shown astonishing efficacy in the treatment of various autoimmune diseases. However, the mechanisms underlying these immunosuppressive properties remain poorly understood. Here, we generated a lymph node single-cell transcriptomic atlas of GMSC-treated experimental autoimmune uveitis mice. GMSC exerted profound rescue effects on T cells, B cells, dendritic cells, and monocytes. GMSCs rescued the proportion of T helper 17 (Th17) cells and increased the proportion of regulatory T cells. In addition to globally altered transcriptional factors (Fosb and Jund), we observed cell type-dependent gene regulation (e.g., Il17a and Rac1 in Th17 cells), highlighting the GMSCs' cell type-dependent immunomodulatory capacity. GMSCs strongly influenced the phenotypes of Th17 cells, suppressing the formation of the highly inflammatory CCR6-CCR2+ phenotype and enhancing the production of interleukin (IL) -10 in the CCR6+CCR2+ phenotype. Integration of the glucocorticoid-treated transcriptome suggests a more specific immunosuppressive effect of GMSCs on lymphocytes.

[In vivo imaging in tumor-bearing animals and pharmacokinetics of PEGylated liposomes modified with RGD cyclopeptide].

The hydroxycamptothecin (HCPT) PEGylated liposomes (HCPT-LP) were modified with RGD cyclopeptide formed the tumor-targeting liposomes (HCPT-RGD-LP). HCPT-LP and HCPT-RGD-LP were injected intravenously with single dose of 5 mg x kg(-1) to rats. The drug concentration in plasma was determined and the pharmacokinetic behaviour was compared. The HCPT distribution in heart, liver, spleen, lung, kidney and plasma of mice was investigated following intravenous administration of HCPT-LP and HCPT injection. The nude mice implanted human hepatoma HepG2 cells were studied by in vivo imaging. The fluorescent probe was DiR and the nude mice were injected with DiR PEGylated liposomes (DiR-LP) and DiR-LP modified with RGD cyclopeptide (DiR-RGD-LP). The results showed that there was no significant difference (P > 0.05) of main pharmacokinetic parameters t1/2beta, CL, V(c), AUC(0-48 h), AUC(0-inifinity), MRT(0-48 h), MRT(0-infinity) between HCPT-RGD-LP and HCPT-LP. HCPT-LP had a remarkably better long-circulating effect than HCPT injection in mice and the concentration of HCPT was highest in liver. The DiR accumulation in tumors of DiR-RGD-LP was higher than that of DiR-LP by the visualized fluorescence of in vivo imaging. It indicated that such PEGylated liposomes modified with RGD cyclopeptide could improve the tumor targeting efficacy.

[Comparison of activated carbon and ultrafiltration technique in the production process of huoxue tongluo injection].

OBJECTIVE: To research the applicability of activated carbon and ultrafiltration technique in the production process of Huoxue Tongluo Injection. METHODS: The kinetic-turbidimetric method was used to determine the content of bacterial endotoxins in Huoxue Tongluo solution. Particle size change in Huoxue Tongluo solution was determined by nanometer particle size instrument before and after the use of different concentration activated carbon and different molecular weight ultrafiltration membrane. RESULTS: The removal efficacy of bacterial endotoxins was 65.2%, 77.5%, 80.4% by using three concentrations of active carbon at 0.05%, 0.10%, 0.30% in Huoxue Tongluo Injection, respectively. It was above 95% by using cutoff molecular weight both 5 kDa and 10 kDa ultrafiltration membrane. Measure results by nanometer particle size instrument showed that particle size of filter liquor by 10 kDa cutoff molecular weight ultrafiltration membrane was much smaller than that of by use of different concentration activated carbon. CONCLUSION: Ultrafiltration method is more suitable to the removal of bacterial endotoxins. The solution is more clear after using ultrafiltration method, and large particles of solution is removed. The ultrafiltration method provides the basis for injection production.

Characterization of cold atmospheric plasma-modified dentin collagen.

The aim of this study was to evaluate the crosslinking effect of the radio-frequency atmospheric-pressure glow discharge (RF-APGD) plasma jet treatment on dentin collagen. The dentin collagen was treated by an RF-APGD plasma jet with the gas temperature of 4°C under different treatment times, while the control was a non-treatment group. The dentin collagen was characterized in terms of atomic force microscopy-based nanoindentation, differential scanning calorimeter, Raman analysis and X-ray photoelectron spectroscopy (XPS) measurement. The crosslinking effect of the plasma-treated dentin collagen was found compared to that of the control group. The elastic modulus and denaturation temperature of the dentin collagen after plasma treatment for 30 s were significantly higher than those in the control group (p<0.05). The RF-APGD plasma jet treatment can promote the crosslinking of the dentin collagen, which is of great significance to improve its mechanical and thermal stabilities.

Bioactive Monomer and Polymer Polyketides from Edible Mushroom Cortinarius caerulescens as Glutamate Dehydrogenase Inhibitors and Antioxidants.

Two new polyketides named rufoolivacin E and viocristin B, a new natural product named 1-hydroxy-3,6,8-trimethoxyanthraquinone, and 13 known compounds were isolated from edible mushroom Cortinarius purpurascens in this work. Their structures were assigned on the basis of high-resolution electrospray ionization mass spectrometry, 1D and 2D nuclear magnetic resonance, and electronic circular dichroism data. Notably, the enzyme activity test on glutamate dehydrogenase indicated that 1, 3, 4, 5, 6, 10, 11, and 15 displayed an excellent inhibition effect. Further kinetic studies showed that the most potent compounds, 4 and 10, possess great potential as competitive inhibitors of glutamate dehydrogenase. Molecular docking and computational chemistry were applied to illustrate the binding mechanism in detail. 2,2-Diphenyl-1-picrylhydrazyl and reactive oxygen species assay results showed that compounds 1, 2, 3, and 8 exhibited significant antioxidant activities with IC50 values of 7.0 ± 0.3, 8.6 ± 0.1, 7.5 ± 0.1, and 2.8 ± 0.2 µg mL-1, respectively. Thus, Cortinarius caerulescens represents a novel resource of these polyketides to be utilized in food selection and drug discovery.

Galvanic-Replacement-Assisted Surface-Initiated Atom Transfer Radical Polymerization for Functional Polymer Brush Engineering.

Here we present a facile and robust strategy, namely, galvanic-replacement-assisted surface-initiated Cu(0)-mediated atom transfer radical polymerization (gr-SI-Cu0ATRP, or gr-SI-Cu0CRP) for polymer brush engineering under ambient conditions. In gr-SI-Cu0ATRP, highly active and nanostructured Cu(0) surfaces are obtained by a simple galvanic replacement on zinc/aluminum surfaces in dilute Cu2+ solution. Polymer brush growth rate is extremely high (up to ∼904 nm in 30 min polymerization); meanwhile, both nano Cu(0) surfaces and Cu2+ solution can be reused multiple times without losing grafting efficiency. We also demonstrate that the gr-SI-Cu0ATRP is advantageous for polymer brush engineering on arbitrary substrates, including flexible (polyethylene terephthalate), curved (polycarbonate), and porous (anodic aluminum oxide), and endow the substrates with various functionalities, for example, anti-icing, antifogging, and ion selectivity.

Ultrastructural Analysis of Er:YAG Lased Bovine Dentin Contaminated by Cariogenic Bacteria.

Objective: The purpose of this study is to investigate the crystal structure of bacteria-contaminated bovine dentin after Er:YAG laser irradiation at various energy densities from macroscale, microscale, and nanoscale. Background: Er:YAG laser can change the morphology and chemical components of dentin. Few preliminary researchers investigate the laser effect on crystal in dentin tissue. Methods: Twenty dentin specimens from bovine incisors were cocultured with S. mutans (UA 159) and divided into four groups with diverse Er:YAG laser irradiation energy (0, 6.37, 12.73, 19.11 J/cm2). The ultrastructure of dentin before and after laser irradiation was investigated with nanoanalytical electron microscopy. X-ray diffraction provided the information of lattice parameters in dentin. The morphology of dentin was observed by scanning electron microscopy. High-resolution transmission electron microscope images and selected-area electron diffraction patterns were obtained for characterizing crystal domain size, structure, and microenvironment of dentin. Results: The combination of these methods disclosed that there exist mineralized, demineralized, and remineralized dentin in the bacteria-invaded dentin and can be feasibly recognized using morphological features. Laser treatments influence hydroxyapatite (HAp) crystals in dentin tissue in different ways: needle HAp in mineralized dentin tissue keeps intact with laser irradiation of no higher than 19.11 J/cm2; laser irradiation improves the crystallinity of lamella HAp by domain growth and rearranges its growth orientations. Conclusions: We report an unprecedented presence of remineralization zone consisting of lamella HAp crystals with distinct high-index planes. These findings have broad implications on the role of laser operation in driving biomineralization and shed new insights into a possible relationship between laser irradiation and remineralization.