Liquid Crystals: Versatile Self-Organized Smart Soft Materials.

Smart soft materials are envisioned to be the building blocks of the next generation of advanced devices and digitally augmented technologies. In this context, liquid crystals (LCs) owing to their responsive and adaptive attributes could serve as promising smart soft materials. LCs played a critical role in revolutionizing the information display industry in the 20th century. However, in the turn of the 21st century, numerous beyond-display applications of LCs have been demonstrated, which elegantly exploit their controllable stimuli-responsive and adaptive characteristics. For these applications, new LC materials have been rationally designed and developed. In this Review, we present the recent developments in light driven chiral LCs, i.e., cholesteric and blue phases, LC based smart windows that control the entrance of heat and light from outdoor to the interior of buildings and built environments depending on the weather conditions, LC elastomers for bioinspired, biological, and actuator applications, LC based biosensors for detection of proteins, nucleic acids, and viruses, LC based porous membranes for the separation of ions, molecules, and microbes, living LCs, and LCs under macro- and nanoscopic confinement. The Review concludes with a summary and perspectives on the challenges and opportunities for LCs as smart soft materials. This Review is anticipated to stimulate eclectic ideas toward the implementation of the nature's delicate phase of matter in future generations of smart and augmented devices and beyond.

The association between polyunsaturated fatty acids and periodontitis: NHANES 2011-2014 and Mendelian randomisation analysis.

BACKGROUND: We aimed to explore the association and potential causality between polyunsaturated fatty acids concentrations and the risk of periodontal disease. MATERIALS AND METHODS: Data were collected from the 2011-2014 National Health and Nutrition Examination Survey (NHANES). Weighted logistic regression analysis and restricted cubic spline (RCS) analysis were used to analyse the associations of the concentrations of omega-3 and omega-6 fatty acids and the omega-6/omega-3 fatty acids ratio with the risk of periodontitis. E-value and propensity score matching (PSM) analyses were used for sensitivity analyses. In addition, two-sample Mendelian randomisation (MR) analyses were performed to assess the potential causal impact of the concentrations of those fatty acids on periodontitis risk. RESULTS: A total of 2462 participants from the NHANES were included. Logistic regression analysis revealed that high omega-3 fatty acids levels were negatively associated with the risk of developing periodontitis (P < 0.05), while the omega-6/omega-3 fatty acids ratio was positively associated with the risk of developing periodontitis (P < 0.05). There was no significant association between omega-6 concentrations and the risk of periodontitis. The findings mentioned above were confirmed by analysis following a 1:1 PSM. Furthermore, MR examination of the two samples indicated no possible causal link between the risk of periodontitis and the concentrations of omega-3 or omega-6 fatty acids or the ratio of omega-6 to omega-3 fatty acids (P > 0.05). CONCLUSION: Although omega-3 fatty acids and the omega-6/omega-3 fatty acids ratio were associated with the risk of periodontitis in cross-sectional studies, the MR results did not support a causal relationship between them. Therefore, there is no indication that an increase in the omega-3 fatty acids concentration or a decrease in the omega-6/omega-3 fatty acids ratio may be beneficial for preventing periodontitis.

Efficacy of the dual-action GA-KR12 peptide for remineralising initial enamel caries: an in vitro study.

OBJECTIVE: To investigate the antibiofilm and remineralising effects of the dual-action peptide GA-KR12 on artificial enamel caries. MATERIALS AND METHODS: Enamel blocks with artificial caries were treated with sterilised deionised water as control or GA-KR12. The blocks underwent biochemical cycling with Streptococcus mutans for 3 weeks. The architecture, viability, and growth kinetics of the biofilm were determined, respectively, by scanning electron microscopy (SEM), confocal laser scanning microscopy, and quantitative (culture colony-forming units, CFUs). The mineral loss, calcium-to-phosphorus ratio, surface morphology, and crystal characteristics of the enamel surface were determined, respectively, using micro-computed tomography, energy dispersive spectroscopy, SEM, and X-ray diffraction (XRD). RESULTS: SEM showed confluent growth of S. mutans in the control group but not in the GA-KR12-treated group. The dead-to-live ratios of the control and GA-KR12-treated groups were 0.42 ± 0.05 and 0.81 ± 0.08, respectively (p < 0.001). The log CFUs of the control and GA-KR12-treated groups were 8.15 ± 0.32 and 6.70 ± 0.49, respectively (p < 0.001). The mineral losses of the control and GA-KR12-treated groups were 1.39 ± 0.09 gcm-3 and 1.19 ± 0.05 gcm-3, respectively (p < 0.001). The calcium-to-phosphorus molar ratios of the control and GA-KR12-treated groups were 1.47 ± 0.03 and 1.57 ± 0.02, respectively (p < 0.001). A uniformly remineralised prismatic pattern on enamel blocks was observed in the GA-KR12-treated but not in the control group. The hydroxyapatite in the GA-KR12-treated group was better crystallised than that in the control group. CONCLUSION: The dual-action peptide GA-KR12 inhibited the growth of S. mutans biofilm and promoted the remineralisation of enamel caries. CLINICAL RELEVANCE: GA-KR12 potentially is applicable for managing enamel caries.

Fabrication of Multilayered Biofunctional Material with an Enamel-like Structure.

The oral cavity is an environment with diverse bacteria; thus, antibacterial materials are crucial for treating and preventing dental diseases. There is a high demand for materials with an enamel-like architecture because of the high failure rate of dental restorations, due to the physical differences between dental materials and enamel. However, recreating the distinctive apatite composition and hierarchical architecture of enamel is challenging. The aim of this study was to synthesize a novel material with an enamel-like structure and antibacterial ability. We established a non-cell biomimetic method of evaporation-based bottom-up self-assembly combined with a layer-by-layer technique and introduced an antibacterial agent (graphene oxide) to fabricate a biofunctional material with an enamel-like architecture and antibacterial ability. Specifically, enamel-like graphene oxide-hydroxyapatite crystals, formed on a customized mineralization template, were assembled into an enamel-like prismatic structure with a highly organized orientation preferentially along the c-axis through evaporation-based bottom-up self-assembly. With the aid of layer-by-layer absorption, we then fabricated a bulk macroscopic multilayered biofunctional material with a hierarchical enamel-like architecture. This enamel-inspired biomaterial could effectively resolve the problem in dental restoration and brings new prospects for the synthesis of other enamel-inspired biomaterials.

Diagnostic value of loop-mediated isothermal amplification assay for hand, foot, and mouth disease.

BACKGROUND: Nowadays, hand, foot, and mouth disease (HFMD) has a significant negative impact on children's health, especially in the Asia-Pacific region. Loop-mediated isothermal amplification assay (LAMP) is a highly efficient and convenient novel tool. However, its diagnostic accuracy for HFMD is still not clear. Therefore, we conducted a meta-analysis in order to evaluate the potential of LAMP assay for the diagnosis of HFMD, in which the reference standard was polymerase chain reaction (PCR). METHODS: A protocol was predetermined (CRD42020212882) in PROSPERO. We retrieved seven databases including PubMed for relevant studies published before October 2020. Articles were included if they compared the diagnostic efficiency of LAMP with PCR for HFMD through detecting clinical samples which was more than 15. Statistical analysis was performed by STATA 15.1 software. Risk of bias and applicability were assessed using Quality Assessment of Diagnostic Accuracy Studies. No funding was used for the study. RESULTS: A total of 18 retrospective studies including 2495 samples from China were finally included. Reference standards of them included RT-PCR and non-RT-PCR. The merged sensitivity and specificity with 95% confidence interval (95% CI) were 1.00 (0.97-1.00) and 0.97 (0.88-0.99), respectively. The pooled PLR, NLR, and DOR with 95% CI were 11.17 (5.91-21.11), 0.05 (0.03-0.09), and 538.12 (183.17-1580.83), respectively. The AUC of SROC was 1.00 (95% CI: 0.99-1.00). CONCLUSION: In conclusion, our research revealed high sensitivity and specificity of LAMP in diagnosing HFMD. However, more high-quality research is required to prove this conclusion.

Functionalized Resins for the Synthesis of Peptide Alcohols.

Peptide alcohols are clinically important compounds that are underexplored in structure-activity relationship (SAR) studies in drug discovery. One reason for this underutilization is that current syntheses are laborious and time consuming. Herein, we describe the preparation and utility of Rink, Ramage, and Sieber-chloride resins, which enables the use of a general, easy and practical method for the attachment of fluorenylmethoxycarbonyl (Fmoc)-amino alcohols to a solid support, in the synthesis of peptide alcohols. This method is the first straightforward Fmoc/tBu synthesis of peptide alcohols starting from a pre-loaded resin. The synthesized peptide alcohols can be detached from the linkers through conventional methods. Treatment with trifluoroacetic acid (TFA) (95 %) and scavengers such as triisopropylsilane and water for 2 h is sufficient to obtain a fully deprotected peptide alcohol, while treatment with 20 % hexafluoroisopropanol in dichloromethane renders a fully protected peptide alcohol that can be further modified at the C-terminus. As examples, the new resins were used in straightforward, relatively rapid syntheses of the peptide alcohols octreotide, alamethicin, and a segment of trichogin GA IV, as well as the first synthesis of stapled peptide alcohols.

Characterization of a Cu2+, SDS, alcohol and glucose tolerant GH1 ß-glucosidase from Bacillus sp. CGMCC 1.16541.

A ß-glucosidase gene (bsbgl1a) from Bacillus sp. CGMCC 1.16541 was expressed in Escherichia coli BL21 and subsequently characterized. The amino acid sequence shared 83.64% identity with ß-glucosidase (WP_066390903.1) from Fictibacillus phosphorivorans. The recombinant ß-glucosidase (BsBgl1A) had a molecular weight of 52.2 kDa and could hydrolyze cellobiose, cellotriose, cellotetrose, p-nitrophenyl-ß-D-glucopyranoside (pNPG), and p-nitrophenyl-ß-D-xylopyranoside (pNPX). Optimal activity for BsBgl1A was recorded at 45 °C with a pH between 5.6 and 7.6, and 100% of its activity was maintained after a 24 h incubation between pH 4 and 9. Kinetic characterization revealed an enzymatic turnover (Kcat) of 616 ± 2 s-1 (with cellobiose) and 3.5 ± 0.1 s-1 (with p-nitrophenyl-ß-D-glucopyranoside). Interestingly, the recombinant enzyme showed cupric ion (Cu2+), sodium dodecyl sulfate (SDS) and alcohol tolerance at 10 mM for Cu2+ and 10% for both SDS and alcohol. Additionally, BsBgl1A had high tolerance for glucose (Ki = 2095 mM), which is an extremely desirable feature for industrial applications. Following the addition of BsBgl1A (0.05 mg/ml) to a commercial cellulase reaction system, glucose yields from sugarcane bagasse increased 100% after 1 day at 45 °C. This work identifies a Cu2+, SDS, alcohol, and glucose tolerant GH1 ß-glucosidase with potential applications in the hydrolysis of cellulose for the bioenergy industry.

A highly conserved amino acid in VP1 regulates maturation of enterovirus 71.

Enterovirus 71 (EV71) is the major causative agent of hand, foot and mouth disease (HFMD) in children, causing severe clinical outcomes and even death. Here, we report an important role of the highly conserved alanine residue at position 107 in the capsid protein VP1 (VP1A107) in the efficient replication of EV71. Substitutional mutations of VP1A107 significantly diminish viral growth kinetics without significant effect on viral entry, expression of viral genes and viral production. The results of mechanistic studies reveal that VP1A107 regulates the efficient cleavage of the VP0 precursor during EV71 assembly, which is required, in the next round of infection, for the transformation of the mature virion (160S) into an intermediate or A-particle (135S), a key step of virus uncoating. Furthermore, the results of molecular dynamic simulations and hydrogen-bond networks analysis of VP1A107 suggest that flexibility of the VP1 BC loop or the region surrounding the VP1107 residue directly correlates with viral infectivity. It is possible that sufficient flexibility of the region surrounding the VP1107 residue favors VP0 conformational change that is required for the efficient cleavage of VP0 as well as subsequent viral uncoating and viral replication. Taken together, our data reveal the structural role of the highly conserved VP1A107 in regulating EV71 maturation. Characterization of this novel determinant of EV71 virulence would promote the study on pathogenesis of Enteroviruses.

A tooth-binding antimicrobial peptide to prevent the formation of dental biofilm.

Dental caries is primarily caused by pathogenic bacteria infection, and Streptococcus mutans is considered a major cariogenic pathogen. Moreover, antimicrobial peptides have been considered an alternative to traditional antibiotics in treating caries. This study aimed to design a tooth-binding antimicrobial peptide and evaluate its antimicrobial efficacy against S. mutans. An antimicrobial peptide of polyphemusin I (PI) was modified by grafting a tooth-binding domain of diphosphoserine (Ser(p)-Ser(p)-) to create the peptide of Ser(p)-Ser(p)-polyphemusin I (DPS-PI). PI and DPS-PI were synthesized by Fmoc solid-phase peptide synthesis. The minimum inhibitory concentration of PI and DPS-PI against S. mutans were tested. Scanning electron microscopy (SEM) were used to observe the growth of S. mutans on PI and DPS-PI treated enamel surfaces. The growth of S. mutans was evaluated by optical density (OD) at 590 nm. Inhibition of dental plaque biofilm development in vivo were investigated. The cytocompatibility to bone mesenchymal stem cells (BMSCs) was tested. The MIC of PI and DPS-PI were 40 and 80 µg/ml, respectively. SEM images showed that S. mutans were sparsely distributed on the DPS-PI treated enamel surface. OD findings indicated that DPS-PI maintained its inhibition effect on S. mutans growth after 24 h. The incisor surfaces of rabbits treated with DPS-PI developed significantly less dental plaque biofilm than that on PI treated surfaces. The DPS-PI had good biocompatibility with the cells. We successfully constructed a novel tooth-binding antimicrobial peptide against S. mutans in vitro and inhibited dental plaque biofilm development in vivo. DPS-PI may provide a feasible alternative to conventional antibiotics for the prevention and treatment of dental caries. Dental caries is primarily caused by pathogenic bacteria infection, and Streptococcus mutans is considered a major cariogenic pathogen. A tooth-binding antimicrobial peptide was designed by grafted diphosphoserine (-Ser(p)-Ser(p)-) to the structure of polyphemusin I. This novel tooth-binding antimicrobial peptide can inhibit dental plaque biofilm development and thus provide a feasible alternative to conventional antibiotics for the prevention and treatment of dental caries.

Lithium doped silica nanospheres/poly(dopamine) composite coating on polyetheretherketone to stimulate cell responses, improve bone formation and osseointegration.

Osseointegration is crucial for early fixation as well as long-term success of orthopedic implants. Bioactive composite containing lithium doping silica nanospheres (LSNs) and poly(dopamine) (PDA) were coated on polyetheretherketone (PK) surface (LPPK), and effects of the LSNs/PDA composite (LPC) coating on the biological properties of LPPK were assessed both in vitro and in vivo. Results showed that LPPK with improved bioactivity remarkably promoted apatite mineralization in simulated body fluid (SBF) compared with PDA coated on PK (PPK) and PK. Moreover, the LPPK remarkably stimulated rat bone marrow stromal cells (rBMSCs) responses compared with PPK and PK. Furthermore, the LPPK significantly promoted bone tissues responses in vivo compared with PPK and PK. It could be suggested that the improvements of cells and bone tissues responses were attributed to the surface characteristics of the bioactive LPC coating on LPPK. The LPPK would be a great candidate for orthopedic and dental applications.

Systemic manifestations of primary Sjögren's syndrome in the NOD.B10Sn-H2b/J mouse model.

Animal models that recapitulate human disease are crucial for the study of Sjögren's Syndrome (SS). While several SS mouse models exist, there are few primary SS (pSS) models that mimic systemic disease manifestations seen in humans. Similar to pSS patients, NOD.B10Sn-H2b/J (NOD.B10) mice develop exocrine gland disease and anti-nuclear autoantibodies. However, the disease kinetics and spectrum of extra-glandular disease remain poorly characterized in this model. Our objective was to characterize local and systemic SS manifestations in depth in NOD.B10 female mice at early and late disease time points. To this end, sera, exocrine tissue, lung, and kidney were analyzed. NOD.B10 mice have robust lymphocytic infiltration of salivary and lacrimal tissue. In addition, they exhibit significant renal and pulmonary inflammation. We identified numerous autoantibodies, including those directed against salivary proteins. In conclusion, the NOD.B10 model recapitulates both local and systemic pSS disease and represents an excellent model for translational studies.

Evaluation of the Hematologic Safety of Same Day Versus Standard Administration (24- to 72-Hour Delay) of Pegfilgrastim in Gynecology Oncology Patients Undergoing Cytotoxic Chemotherapy.

OBJECTIVE: We assessed the safety and efficacy of administration of pegfilgrastim on the same day compared with standard administration 24 to 72 hours after chemotherapy in patients with gynecologic malignancies. METHODS: A retrospective review was conducted on patients undergoing pegfilgrastim to mitigate the myelosuppressive consequences of chemotherapy. The primary outcome was incidence of grade 3 to 4 neutropenia following pegfilgrastim for same-day administration (D1) versus standard administration (D2+). Secondary outcomes included dose delay, regimen change, hospitalization due to neutropenia, and incidence of febrile neutropenia. RESULTS: Four hundred twenty-one patients with 2071 administrations of pegfilgrastim were included. Five hundred six administrations of pegfilgrastim were given on D1 compared with 1565 administrations on D2+. The most common malignancy was ovarian cancer (79.1%), followed by endometrial (14.5%). Comparing the D1 and D2+ cohorts, noninferiority was not established for the incidence of grade 3 to 4 neutropenia (2.6% vs 1.8%, adjusted relative risk [aRR], 1.6; 90% confidence interval [CI], 0.87-3.2) or dose modification (6.5% vs 4.9%; aRR, 1.3; 90% CI, 0.9-1.8). However, the rate of treatment delays (7.3% vs 9.4%; aRR, 0.8; 90% CI, 0.6-1.1) in the D1 and D2+ groups suggested that delays in the D1 group were not more common than in the D2+ group. CONCLUSIONS: The incidence of hematologic toxicities and dose modification in patients receiving same-day pegfilgrastim were not as low as in those undergoing standard administration. However, treatment delays were found to be no more frequent in those receiving same-day pegfilgrastim versus standard administration. Same-day administration of pegfilgrastim is a reasonable option.

Severe pegfilgrastim-induced bone pain completely alleviated with loratadine: A case report.

Febrile neutropenia is an oncologic emergency that can result in serious consequences. Granulocyte colony stimulating factors (G-CSFs) are often used as prophylaxis for febrile neutropenia. Bone pain is the most notorious adverse effect caused by G-CSFs. Specifically, with pegfilgrastim (Neulasta(®)), the incidence of bone pain is higher in practice than was observed during clinical trials. Traditional analgesics, such as non-steroidal anti-inflammatory drugs (NSAIDs) and opioids, can be ineffective in severe pegfilgrastim-induced bone pain. With the high frequency of this adverse effect, it is clear that health practitioners need additional treatment options for patients who experience severe pegfilgrastim-induced bone pain. The mechanisms of bone pain secondary to G-CSFs are not fully known, but research has shown that histamine release is involved in the inflammatory process. There is scant previous clinical data on antihistamine use in the management of G-CSF-induced pain. We present the first case report in which loratadine prophylaxis completely alleviated NSAID-resistant severe pain secondary to pegfilgrastim. The result showed that loratadine may be a promising option for severe, resistant pegfilgrastim-induced bone pain. Further clinical studies are warranted and ongoing.

Methods for biomimetic remineralization of human dentine: a systematic review.

This study aimed to review the laboratory methods on biomimetic remineralization of demineralized human dentine. A systematic search of the publications in the PubMed, TRIP, and Web of Science databases was performed. Titles and abstracts of initially identified publications were screened. Clinical trials, reviews, non-English articles, resin-dentine interface studies, hybrid layer studies, hybrid scaffolds studies, and irrelevant studies were excluded. The remaining papers were retrieved with full texts. Manual screening was conducted on the bibliographies of remaining papers to identify relevant articles. A total of 716 studies were found, and 690 were excluded after initial screening. Two articles were identified from the bibliographies of the remaining papers. After retrieving the full text, 23 were included in this systematic review. Sixteen studies used analogues to mimic the functions of non-collagenous proteins in biomineralization of dentine, and four studies used bioactive materials to induce apatite formation on demineralized dentine surface. One study used zinc as a bioactive element, one study used polydopamine, and another study constructed an agarose hydrogel system for biomimetic mineralization of dentine. Many studies reported success in biomimetic mineralization of dentine, including the use of non-collagenous protein analogues, bioactive materials, or elements and agarose hydrogel system.

A novel self-assembled oligopeptide amphiphile for biomimetic mineralization of enamel.

BACKGROUND: Researchers are looking for biomimetic mineralization of ena/mel to manage dental erosion. This study evaluated biomimetic mineralization of demineralized enamel induced by a synthetic and self-assembled oligopeptide amphiphile (OPA). RESULTS: The results showed that the OPA self-assembled into nano-fibres in the presence of calcium ions and in neutral acidity. The OPA was alternately immersed in calcium chloride and sodium hypophosphate solutions to evaluate its property of mineralization. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) showed nucleation and growth of amorphous calcium phosphate along the self-assembled OPA nano-fibres when it was repetitively exposed to solutions with calcium and phosphate ions. Energy dispersive spectrometry (EDS) confirmed that these nano-particles contained calcium and phosphate. Furthermore, electron diffraction pattern suggested that the nano-particles precipitated on OPA nano-fibres were comparable to amorphous calcium phosphate. Acid-etched human enamel slices were incubated at 37°C in metastable calcium phosphate solution with the OPA for biomimetic mineralization. SEM and X-ray diffraction indicated that the OPA induced the formation of hydroxyapatite crystals in organized bundles on etched enamel. TEM micrographs revealed there were 20-30 nm nano-amorphous calcium phosphate precipitates in the biomimetic mineralizing solution. The particles were found separately bound to the oligopeptide fibres. Biomimetic mineralization with or without the oligopeptide increased demineralized enamel microhardness. CONCLUSIONS: A novel OPA was successfully fabricated, which fostered the biomimetic mineralization of demineralized enamel. It is one of the primary steps towards the design and construction of novel biomaterial for future clinical therapy of dental erosion.

A novel oligopeptide simulating dentine matrix protein 1 for biomimetic mineralization of dentine.

OBJECTIVE: The objectives were to design and fabricate an oligopeptide that simulates dentine matrix protein 1 (DMP1) to study its ability to bind to dentine collagen fibrils and induce biomimetic mineralization for the management of dentine hypersensitivity. MATERIALS AND METHODS: A novel oligopeptide was developed by connecting the collagen-binding domain of DMP1 to the hydrophilic C-terminal of amelogenin. Fluorescein isothiocyanate-coupled oligopeptide was applied to the completely demineralized dentine collagen and examined using fluorescent microscopy. The nucleation and growth of hydroxyapatite were initiated by immersing oligopeptide into calcium chloride and sodium hydrogen phosphate solutions. Scanning electron microscopy (SEM), transmission electron microscopy, and selected area electron diffraction (SAED) were used to examine the formation. Dentine slices were acid-etched, coated with oligopeptide, and immersed into a metastable calcium phosphate solution. Dentine mineralization was evaluated by SEM, X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). RESULTS: Fluorescent dentine collagen was identified in the specimens. The nucleation and growth of crystals were detected after immersing the oligopeptide into calcium chloride and sodium hydrogen phosphate solutions. Under SEM, crystals were observed covering the oligopeptide-coated dentine surface, within the demineralized dentine collagen matrix and occluding dentinal tubules. SAED, XRD, and FTIR confirmed that the crystals were hydroxyapatite. CONCLUSION: A novel oligopeptide-simulating DMP1 was developed, that can bind to collagen fibrils, initiate mineralization, and induce biomimetic mineralization of dentine. CLINICAL RELEVANCE: Biomimetic mineralization of dentine facilitated by this oligopeptide is a potential therapeutic technique for the management of dentine hypersensitivity.

[Spectroscopic analysis of the decay resistance of wood treated with extracts from the xylem of Cinnamomum Camphora with XRD and FTIR approaches].

Four kinds of extracts from the xylem of C. Camphora, ACQ and camphor were selected to make wood preservatives for laboratory toxicity test of wood preservatives for decay fungus. The results showed that the treated blocks with 4% ACQ and 10% methanol extracts could meet the demand of degree I of preservation and showed strong resistance to brown-rot fungus at tack. The wood treated with 4% camphor extracts, 10% ethyl acetate extracts, and 10% acetone extracts reached the demand of degree II and showed moderate decay resistance. The blocks treated with 10% hot water extracts and untreated samples meet the demand of degree III. Through XRD comparison, the author was found that the preservative effects of four extracts are proportional to the degree of crystallinity. Crystallization fields 2 theta diffraction angle were ordered from larger to little as 10% hot wa-ter extracts > untreated samples > 10% acetone extracts > 10% methanol extracts > 1% ethyl acetate extracts. According to FTIR analysis, the amount of degraded cellulose and hemicellulose increased with the decline of characteristic absorption peak at 1,374, 1,160, 1,106, 1,056 and 897 cm(-1), meaning that the preservative effect of corresponding preservatives were getting worse. The peak height of characterization of lignin is higher compared to the untreated wood. I1,510/I1,738, I1,510/I1,374, l51,510/ I1,160 of the treated blocks with 10% methanol extracts and 4% ACQ are the smallest in all the treated blocks, which proved that the degradation ability of brown--rot fungus to the holocellulose is the weakest, and the wood preservative is best.

Extrafibrillar demineralization: Yes or no?

OBJECTIVE: Extrafibrillar demineralization is considered to be an ideal solution for addressing the durability of resin-dentin bonding interfaces. However, its theoretical basis is contradictory to ionization equilibrium of hydroxyapatite dissolution. In this study, various calcium chelators were selected as dentin conditioners to explore the essence of dentin demineralization with chelators and its effect on resin-dentin adhesion. METHODS: Polyethyleneimine grafted with EDTA and polyacrylic acid sodium (PAAN450k) larger than 40 kDa, as well as PAAN (PAAN3k) and EDTA smaller than 6 kDa, were prepared as dentin conditioners. The dentin powder was designed to characterize whether it would demineralize without contact with PAAN450k. Dentin demineralization effect with four conditioners was evaluated with field emission scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, atomic force microscopy and quantification of hydroxyproline concentration after enzymatic degradation. Micro-tensile bond strength (µTBS) test and failure mode analysis were employed to assess the bonding effect of the four chelators in both wet and dry bonding, with H3PO4 wet bonding serving as the control group. RESULTS: Demineralization occurs when PAAN450k was not in direct contact with the dentin powder. The extrafibrillar demineralization cannot be induced by any chelator regardless of its molecular weight. Complete demineralization including extrafibrillar and intrafibrillar demineralization would occur with sufficient interaction time. Moreover, chelators could not provide a reliable dentin bonding effect under a short interaction time. SIGNIFICANCE: From the perspective of theory and application, extrafibrillar demineralization is not a reliable strategy, which provides a reminder for exploring new strategies in the future.

Sunflower pollen-derived microcapsules adsorb light and bacteria for enhanced antimicrobial photothermal therapy.

Bacterial infection is one of the most serious clinical complications, with life-threatening outcomes. Nature-inspired biomaterials offer appealing microscale and nanoscale architectures that are often hard to fabricate by traditional technologies. Inspired by the light-harvesting nature, we engineered sulfuric acid-treated sunflower sporopollenin exine-derived microcapsules (HSECs) to capture light and bacteria for antimicrobial photothermal therapy. Sulfuric acid-treated HSECs show a greatly enhanced photothermal performance and a strong bacteria-capturing ability against Gram-positive bacteria. This is attributed to the hierarchical micro/nanostructure and surface chemistry alteration of HSECs. To test the potential for clinical application, an in situ bacteria-capturing, near-infrared (NIR) light-triggered hydrogel made of HSECs and curdlan is applied in photothermal therapy for infected skin wounds. HSECs and curdlan suspension that spread on bacteria-infected skin wounds of mice first capture the local bacteria and then form hydrogels on the wound upon NIR light stimulation. The combination shows a superior antibacterial efficiency of 98.4% compared to NIR therapy alone and achieved a wound healing ratio of 89.4%. The current study suggests that the bacteria-capturing ability and photothermal properties make HSECs an excellent platform for the phototherapy of bacteria-infected diseases. Future work that can fully take advantage of the hierarchical micro/nanostructure of HSECs for multiple biomedical applications is highly promising and desirable.

A Bayesian benchmark concentration analysis for urinary fluoride and intelligence in adults in Guizhou, China.

Environmental fluoride exposure has been linked to numerous cases of fluorosis worldwide. Previous studies have indicated that long-term exposure to fluoride can result in intellectual damage among children. However, a comprehensive health risk assessment of fluorosis-induced intellectual damage is still pending. In this research, we utilized the Bayesian Benchmark Dose Analysis System (BBMD) to investigate the dose-response relationship between urinary fluoride (U-F) concentration and Raven scores in adults from Nayong, Guizhou, China. Our research findings indecate a dose-response relationship between the concentration of U-F and intelligence scores in adults. As the benchmark response (BMR) increased, both the benchmark concentration (BMCs) and the lower bound of the credible interval (BMCLs) increased. Specifically, BMCs for the association between U-F and IQ score were determined to be 0.18 mg/L (BMCL1 = 0.08 mg/L), 0.91 mg/L (BMCL5 = 0.40 mg/L), 1.83 mg/L (BMCL10 = 0.83 mg/L) when using BMRs of 1 %, 5 %, and 10 %. These results indicate that U-F can serve as an effective biomarker for monitoring the loss of IQ in population. We propose three interim targets for public policy in preventing interllectual harm from fluoride exposure.