The influence on surface characteristic and biocompatibility of nano-SnO2-modified titanium implant material using atomic layer deposition technique.

BACKGROUND/PURPOSE: To investigate the surface characteristics of titanium (Ti) implant materials, which were coated with different thicknesses of nanoscale tin oxide (SnO2) using the atomic layer deposition technique, and evaluated its biological performance on human embryonic palatal mesenchyme (HEPM) cells. METHODS: The thickness of the coating layer on Ti was 0 (Ti0), 20 nm (Ti20), 50 nm (Ti50), and 100 nm (Ti100), respectively. The surface morphology was observed with an SEM and AFM. The root mean square roughness of micron-scale (mRq) and nanoroughness (nRq) of Ti discs' surface were measured. The Alamar blue (AB) assay and F-actin fluorescence staining were used to evaluate the biocompatibility, and the osteocalcin (OCN) was measured to clarify the differentiation of HEPM cells on materials. RESULTS: In the coating groups, the mRq was decreased, but the nRq was increased. The spreading and polygonal morphology of HEPMs was apparent in coating groups. On Day 4, the survival rate of HEPM cells on Ti0 was higher than on Ti20 and Ti50. There was no significant difference on Day 7, Day 10, and Day 14. The OCN was significantly higher on Day 14 in all the coating groups than Ti0. CONCLUSION: The results showed that the cell growth was intensified with rough surfaces. However, the OCN and morphology change was prominent when the nanoroughness was increased, which meant the increased nanoroughness might enhance OCN production and improve the tendency of osseointegration. The nanoscale SnO2 coating could increase the ability of bone formation but not cell growth.

Cascade C-H-Activated Polyannulations toward Ring-Fused Heteroaromatic Polymers for Intracellular pH Mapping and Cancer Cell Killing.

The development of straightforward and efficient synthetic methods toward ring-fused heteroaromatic polymers with attractive functionalities has great significance in both chemistry and materials science. Herein, we develop a facile cascade C-H-activated polyannulation route that can in situ generate multiple ring-fused aza-heteroaromatic polymers from readily available monomers in an atom-economical manner. A series of complex polybenzimidazole derivatives with high absolute molecular weights of up to 24 000 are efficiently produced in high yields within 2 h. Benefiting from their unique imidazole-containing ring-fused structures with multiple aryl pendants, the obtained polymers show excellent thermal and morphological stability, good solution processability, high refractive index, small chromic dispersion, as well as remarkable acid-base-responsive fluorescence. Taking advantage of the ratiometric fluorescence response of the triphenylamine-substituted heteroaromatic polymer to pH variations, we successfully apply it as a sensitive fluorescence probe for the mapping and quantitative analysis of intracellular pH in live cells. Furthermore, through the simple N-methylation reaction of the ring-fused polybenzimidazoles, diverse azonia-containing polyelectrolytes are readily produced, which can efficiently kill cancer cells via the synergistic effects of dark toxicity and phototoxicity.

In Situ Generation of Heterocyclic Polymers by Triple-Bond Based Polymerizations.

Stemming from unique ring structures, heterocyclic polymers exhibit distinguished electrical, mechanical, and photophysical properties and have been widely used in a variety of important applications. Along with the technological significance are the challenges in their synthesis. Traditional synthetic strategies toward heterocyclic polymers often require the direct attachment of heterocycles to polymer backbones, which are generally limited by the lack of suitable and low-cost heterocyclic monomers, tedious reaction process, difficulties in incorporation of multiple substitutents, etc. Alternatively, in situ construction of heterocyclic polymers via triple-bond based polymerization offers promising prospects. This review summarized the recent progress on polymerizations of triple-bond based monomers including alkynes, nitriles, and isonitriles that can in situ generate heterocyclic polymers. The properties and advanced applications of the derived heterocyclic polymers will also be discussed. Finally, the future perspectives and challenges in this field will be addressed.

One-Step Multicomponent Polymerizations for the Synthesis of Multifunctional AIE Polymers.

As a new class of functional luminescent materials, polymers with aggregation-induced emission (AIE) feature attract much attention because of their advantages of efficient solid-state fluorescence, excellent processability, structural diversity, and multifunctionalities. Among all polymerization methods toward AIE polymers, multicomponent polymerizations (MCPs) exhibit the merits of simple operation, good atom economy, high polymerization efficiency, broad functional-group tolerance, etc. In this feature article, the recent progress on the development of one-step MCPs for the synthesis of AIE polymers is highlighted. The representative functionalities of the resulting AIE polymers are illustrated. Perspectives on the challenges and future development directions of this field are also discussed.

Mechanochromic Fluorescent Polymers Enabled by AIE Processes.

Polymeric materials are susceptible to the chain re-conformation, reorientation, slippage, and bond cleavage upon mechanical stimuli, which are likely to further grow into macro-damages and eventually lead to the compromise or loss of materials performance. Therefore, it is of great academic importance and practical significance to sensitively detect the local mechanical states in polymers and monitor the dynamic variations in polymer structures and properties under external forces. Mechanochromic fluorescent polymers (MFP) are a class of smart materials by utilizing sensitive fluorescent motifs to detect polymer chain events upon mechanical stimuli. Taking advantage of the unique aggregation-induced emission (AIE) effect, a variety of MFP systems that can self-report their mechanical states and mechano-induced structural and property changes through fluorescence signals have been developed. In this feature article, an overview of the recent progress on MFP systems enabled by AIE process is presented. The main design principles, including physically doping dispersed or microencapsulated AIE luminogens (AIEgens) into polymer matrix, chemically linking AIEgens in polymer backbones, and utilizing the clusterization-triggered emission of polymers containing nonconventional luminogens, are discussed with representative examples. Perspectives on the existing challenges and problems in this field are also discussed to guide future development.

Functional Heterochain Polymers Constructed by Alkyne Multicomponent Polymerizations.

Heterochain polymers such as DNA and proteins are abundant in nature, but they are not ubiquitous in man-made polymers due to the synthetic difficulties. Traditional polymerization methodologies including chain polymerization, step-growth polymerization, and coordination polymerization all show obvious drawbacks in synthesizing heterochain polymers. The alkyne multicomponent polymerizations (MCPs) developed in the early 2000s open a new door for the synthesis of conjugated heterochain polymers with diverse structures and unique properties. This review presents the progress in novel heterochain polymers constructed by alkyne-based MCPs in the last three years. The unique properties and high-tech applications brought by heteroatoms and MCPs are summarized and perspectives on future directions are also discussed.

Construction of Functional Hyperbranched Poly(phenyltriazolylcarboxylate)s by Metal-Free Phenylpropiolate-Azide Polycycloaddition.

The 1,3-dipolar cycloaddition of activated internal alkynes with azides has been developed into an efficient polymerization reaction for constructing functional linear 1,4,5-trisubstitued polytriazoles. However, it is rarely employed for the synthesis of hyperbranched polymers. In this work, metal-free polycycloadditions of tris(3-phenylpropiolate)s (1) and tetraphenylethene-containing diazides (2) are performed in dimethylformamide at 100 °C for 7 and 12 h, producing hyperbranched poly(phenyltriazolylcarboxylate)s (hb-PPTCs) with high molecular weights and satisfactory regioregularities in good yields. The hb-PPTCs have good solubility in common organic solvents and high thermal stability. They are non-emissive in solutions, but emit intensively upon aggregation, showing an aggregation-induced emission effect. Their aggregates can work as fluorescent sensors for explosive detection with high sensitivity. Furthermore, the polymers can be utilized for the fabrication of 2D fluorescent patterns with high resolution by UV irradiation through copper grid masks.

Baosteel emission control significantly benefited air quality in Shanghai.

As the largest iron and steel producer in China, a part of Baosteel moved out of Shanghai deserves close attention due to its environmental impact. To understand the effect of Baosteel emission control on air quality in Shanghai, daily PM10, PM2.5, SO2, NO2 and CO were measured from 2010 to 2016. Concentrations of pollutants in Baoshan District presented a decreased trend during 2010-2016, with a reduction rate of 28.6% for PM10, 67.3% for SO2, 8.6% for NO2 and 42.0% for CO. However, fine particle pollution in Baoshan District during 2012-2016 seems to become more prominent, with PM2.5 concentration of 47±28, 45±33, 38±24, 54±41 and 51±34µg/m3, respectively, indicating a slight increase of 8.5% in PM2.5. Concentrations of PM10 and CO decreased by 12.5% and 33.8% in the second half year in 2016 (compared with that in 2015) probably due to closure of blast furnace of Baosteel. Baosteel was identified as the largest pollution source in Baoshan District. Emission from Baosteel accounted for 58.0% of SO2, 43.6% of NO2 and 79.3% of dust in total emission from Baoshan District during 2010-2015. Meanwhile, pollutant emission and coal consumption from Baosteel decreased by 52.0% for SO2, 40.1% for NO2, 15.7% for dust and 22% for coal consumption. Energy consumption in Baoshan District reduced by 31% from 2011 to 2015. Air quality improvement in Shanghai was attributed to local emission reduction, together with regional air quality improvement.

Insights into behavior and mechanism of tetracycline adsorption on virgin and soil-exposed microplastics.

Microplastics (MPs), as vectors of pollutants, have attracted extensive attention because of their environmental effects. However, the adsorption behavior and antibiotic mechanism of environmentally exposed MPs is limited. Here, the adsorption of tetracycline (TC) onto virgin and soil-exposed polylactic acid (PLA), polyvinyl chloride (PVC) and polyethylene (PE) MPs showed that the adsorption capacity of MPs for TC increased after soil exposure, and PLA showed the strongest increase. Soil exposure increased the time to reach equilibrium, and the adsorption rate was controlled by both intraparticle diffusion and membrane diffusion. The isothermal adsorption results of soil-exposed PE and PLA indicated that TC adsorbed on heterogeneous surfaces was affected by the physicochemical adsorption process. The equilibrium absorption capacity of MPs for TC increased by 88% (PLA), 26% (PVC) and 15% (PE) after soil exposure. Soil dissolved organic matter promoted the desorption of TC from MPs, and TC speciation changed with pH. Soil-exposed MPs have the potential to promote TC degradation in solution without the addition of biological inhibitors. Moreover, density functional theory calculations verified that PE and PVC adsorbed TC through physical interactions, while hydrogen bonds were formed on PLA with TC. These results clarified the behavior and mechanisms of TC adsorption on virgin and soil-exposed MPs, which can help in the risk assessment of concomitant pollution of MPs and antibiotics.

Investigating the impact of oral health on pregnancy and offspring outcomes: protocol for the Lifetime Impact of ORal heAlth (LIORA) cohort study.

INTRODUCTION: Oral health is a fundamental component of well-being, and is closely associated with overall health and quality of life. Oral health may also affect the next generation. The children of mothers with poor oral health are likely to also have poor oral health as they go through life. We aim to investigate associations between maternal oral health and general health, pregnancy outcomes, offspring oral health and offspring general health. METHODS AND ANALYSIS: The Lifetime Impact of Oral Health study is a prospective, observational cohort study being done at a single centre in Chongqing, China. A total of 1000 pregnant women will be recruited in their first trimester (11-14 weeks gestation). After obtaining informed consent, general and oral health assessments will be undertaken. Maternal lifestyle, demographic data and biospecimens (blood, hair, urine, nail clippings, saliva, dental plaque, buccal, vaginal and anal swabs) will be collected. Pregnancy outcomes will be recorded at the time of delivery. Cord blood and placenta samples will be collected. The offspring will be followed up for general and oral health examinations, neurodevelopmental assessments and biospecimen (dental plaque, saliva, buccal swabs, exfoliated primary dentition, urine, hair, nail clippings) collection until they are 15 years old. Biological samples will undergo comprehensive metabolomic, microbiome and epigenome analyses. Associations between maternal oral health and general health, pregnancy outcomes, offspring oral health and offspring general health will be investigated and the underlying mechanisms explored. ETHICS AND DISSEMINATION: This project has been approved by the Research Ethics Committee of the Affiliated Hospital of Stomatology of Chongqing Medical University (CQHS-REC-2021 LSNo.23). Participants will be required to provide informed consent to participate in the study. Dissemination of findings will take the form of publications in peer-reviewed journals and presentations at national and international conferences. TRIAL REGISTRATION NUMBER: ChiCTR2100046898.

Functional Polymer Systems with Aggregation-Induced Emission and Stimuli Responses.

Functional polymer systems with stimuli responses have attracted great attention over the years due to their diverse range of applications. Such polymers are capable of altering their chemical and/or physical properties, such as chemical structures, chain conformation, solubility, shape, morphologies, and optical properties, in response to single or multiple stimuli. Among various stimuli-responsive polymers, those with aggregation-induced emission (AIE) properties possess the advantages of high sensitivity, fast response, large contrast, excellent photostability, and low background noise. The changes in fluorescence signal can be conveniently detected and monitored using portable instruments. The integration of AIE and stimuli responses into one polymer system provides a feasible and effective strategy for the development of smart polymers with high sensitivity to environmental variations. Here, we review the recent advances in the design, preparation, performance, and applications of functional synthetic polymer systems with AIE and stimuli responses. Various AIE-based polymer systems with responsiveness toward single physical or chemical stimuli as well as multiple stimuli are summarized with specific examples. The current challenges and perspectives on the future development of this research area will also be discussed at the end of this review.

A natural compound (LCA) isolated from Litsea cubeba inhibits RANKL-induced osteoclast differentiation by suppressing Akt and MAPK pathways in mouse bone marrow macrophages.

ETHNOPHARMACOLOGICAL RELEVANCE: Litsea cubeba (Lour.) Pers. has been traditionally used as a folk prescription for treating rheumatic diseases in China. AIM OF THE STUDY: This study aimed to investigate the effects and underlying mechanism of LCA, a new type of dibenzyl butane lignin compound extracted from L. cubeba, on macrophage colony stimulating factor (M-CSF) plus receptor activator of NF-κB ligand (RANKL)-induced osteoclast differentiation in mouse-derived bone marrow macrophages (BMMs). MATERIAL AND METHODS: TRAP staining, TRAP enzyme activity assay and actin ring staining were applied to identify the effects of LCA on osteoclast differentiation. Protein expression of NFATc1, c-Fos and MMP-9, and phosphorylation of p65, Akt, JNK, ERK and p38 in RANKL-induced osteoclasts was determined using western blotting to investigate the underlying mechanism. RESULTS: LCA significantly suppressed RANKL-induced osteoclast differentiation by inhibiting TRAP activity, decreasing the number of TRAP+ multinuclear osteoclasts and reducing the formation of F-actin ring without obvious cytotoxicity in BMMs. Moreover, LCA treatment strongly reduced protein expression of NFATc1, c-Fos and MMP-9, and attenuated the phosphorylation of p65, Akt, JNK, ERK and p38 in RANKL-stimulated BMMs. CONCLUSIONS: LCA ameliorated RANKL-induced osteoclast differentiation via inhibition of Akt and MAPK signalings in BMMs, and may serve as a potential pro-drug for bone destruction prevention.

Piper sarmentosum Roxb.: A review on its botany, traditional uses, phytochemistry, and pharmacological activities.

ETHNOPHARMACOLOGICAL RELEVANCE: Piper sarmentosum Roxb. (Piperaceae) is a traditional medicinal plant widely distributed in India, Malaysia, Thailand, and the southeastern coastal areas of China including Fujian, Guangdong, and Guizhou. It has been used for centuries for the treatment of wind-cold cough, fever, rheumatism arthralgia, diarrhea dysentery, postpartum foot swelling, stomachache, toothache, diabetes, and traumatic injury. AIMS OF THE REVIEW: To critically anayze the literature for the botany, traditional uses, phytochemistry, pharmacology, toxicity, and clinical trials of P. sarmentosum in order to provide a scientific consensus for further research and discovery of potential candidate drugs. MATERIALS AND METHODS: The contents of this review were sourced from electronic databases including PubMed, SciFinder, Web of Science, Science Direct, Elsevier, Google Scholar, Chinese Knowledge On frastructure (CNKI), Wanfang, Chinese Scientific and Technological Periodical Database (VIP), Chinese Biomedical Database (CBM), Cochrane Controlled register of Clinical Trials, Clinical Trials. gov, and Chinese Clinical Trial Registry. Chinese medicine books published over the years were used to elucidate the traditional uses of P. sarmentosum and additional information was also collected from Yao Zhi website (https://db.yaozh.com/). RESULTS: Phytochemical analyses of the chemical constituents of P. sarmentosum include essential oil, alkaloids, flavonoids, lignans, and steroids. The literature supports the ethnomedicinal uses of P. sarmentosum for the treatment of cold, gastritis, and rheumatoid joint pain, and further confirms its relatively new pharmacological activities, including anti-inflammatory, antineoplastic, and antipyretic activities. Other biological roles such as anti-osteoporosis, antibacterial, antidepressant, anti-atherosclerotic, and hypoglycemic activities have also been reported. However, the methodologies employed in individual studies are limited. CONCLUSIONS: There is convincing evidence from both in vitro and in vivo studies supporting the traditional use of P. sarmentosum and it is imperative that natural bioactive compounds are examined further. More efforts should be focused on the pharmacodynamic constituents of P. sarmentosum to provide practical basis for quality control, and additional studies are needed to understand the mechanism of their action. Further studies on the comprehensive evaluation of medicinal quality and understandings of serum chemistry, multi-target network pharmacology, and molecular docking technology of P. sarmentosum are of great importance and should be considered.

Low loss high index contrast nanoimprinted polysiloxane waveguides.

Nanoimprint lithography is gaining rapid acceptance in fields as diverse as microelectronics and microfluidics due to its simplicity high resolution and low cost. These properties are critically important for the fabrication of photonic devices, where cost is often the major inhibiting deployment factor for high volume applications. We report here on the use of nanoimprint technology to fabricate low loss broadband high index contrast waveguides in a Polysiloxane polymer system for the first time.

Effects of berberine on differentiation and bone resorption of osteoclasts derived from rat bone marrow cells.

OBJECTIVE: To observe the effects of berberine on osteoclastic differentiation and bone resorption action in vitro, and to investigate the cellular mechanism of its inhibitory effects on bone resorption. METHODS: The multinucleated osteoclasts (MNCs) were derived by 1,25-dihydroxyvitamin D3 and dexamethasone from bone marrow cells in the coculture system with primary osteoblastic cells. The tartrate-resistant acid phosphatase (TRAP) staining and image analysis of bone resorption pit on dental slices were used to identify osteoclast. The activity of TRAP was measured by p-nitrophenyl sodium phosphate assay. The bone resorption pit area on the bone slices formed by osteoclasts was measured by computer image processing. RESULTS: At the concentrations of 0.1, 1 and 10 micromol/L, berberine dose-dependently suppressed the formation of TRAP-positive multinucleated cells, the TRAP activity and the osteoclastic bone resorption. The strongest inhibitory effect was exhibited at the concentration of 10 micromol/L, with the inhibiting rate of 60.45%, 42.12% and 72.69% respectively. CONCLUSION: Berberine can decrease bone loss through inhibition of osteoclast formation, differentiation and bone resorption.

Recent New Methodologies for Acetylenic Polymers with Advanced Functionalities.

Polymers synthesized from acetylenic monomers often possess electronically unsaturated fused rings and thus show versatile optoelectronic properties and advanced functionalities. To expand the family of acetylenic polymers, development of new catalyst systems and synthetic routes is critically important. We summarize herein recent research progress on development of new methodologies towards functional polymers using alkyne building blocks since 2014. The polymerizations are categorized by the number of monomer components, namely homopolymerizations, two-component polymerizations, and multicomponent polymerizations. The properties and applications of acetylenic polymers, such as aggregation-induced emission, fluorescent photopatterning, light refraction, chemosensing, mechanochromism, chain helicity, etc., are also discussed.

[IR study of the hardening and maturation of glass ionomer cement].

The set reaction of glass ionomer cement has been investigated by means of IR spectra. It has been found that the band intensity around 1413 cm(-1) due to the vibration of polyacrylate salt increased with aging, and the shoulder band at 950 cm(-1) due to the stretching vibration of Si-OH still appeared during the periods studied. The results are consistent with that of mechanical determination of compressive strength, which suggested that the crosslink density increase resulting from the slow diffusion of Ca2+ and Al3+ is responsible for compressive strength increasing with aging, and forming and maturing of interface layer comprising of silica gel also have a significant effect on the properties of glass ionomer cements.

A Cone-Beam Computed Tomographic Study on Mandibular First Molars in a Chinese Subpopulation.

The purpose of this study was to conduct a cone-beam computed tomographic (CBCT) investigation on the root and canal configuration of the mandibular first molars, especially the morphology of the disto-lingual (DL) root, in a Chinese subpopulation. A total of 910 CBCT images of the mandibular first molars were collected from 455 patients who underwent CBCT examinations as a preoperative assessment for implants or orthodontic treatment. The following information was analyzed and evaluated: tooth position, gender, root and root canal number per tooth, root canal type of the mesial root(s) and distal root(s), angle of the DL root canal curvature, distance between two distal canal orifices in the teeth with DL root, and angle of disto-buccal canal orifice-disto-lingual canal orifice-mesio-lingual canal orifice (DB-DL-ML). Most of the mandibular first molars (64.9%, n = 591) had two roots with three root canals, and most of the mesial root canals (87.7%, n = 798) were type VI. The prevalence of the DL root was 22.1% (n = 201). The right side had a higher prevalence of DL root than the left side (p<0.05). Additionally, the curvature of the DL root canal were greater in the bucco-lingual (BL) orientation (30.10°±14.02°) than in the mesio-distal (MD) orientation (14.03°± 8.56°) (p<0.05). Overall there was a high prevalence of DL root in the mandibular first molars, and most of the DL roots were curved in different degrees. This study provided detailed information about the root canal morphology of the mandibular first molars in a Chinese subpopulation.

Use of cone-beam computed tomography to evaluate root canal morphology and locate root canal orifices of maxillary second premolars in a Chinese subpopulation.

INTRODUCTION: The aim of this study was to investigate root canal morphology and locate root canal orifices of maxillary second premolars in a Chinese subpopulation using cone-beam computed tomographic imaging. METHODS: A total of 392 cone-beam computed tomographic images of maxillary second premolars were obtained from 238 patients who required a preoperative assessment for implant surgery or orthodontic treatment. The number of roots and root canals and root canal configuration were investigated and categorized using Vertucci's criteria. The distance between the root canal orifice and the anatomic apex and the distance between root canal orifices in those teeth with 2 root canals were measured and evaluated. The Fisher exact test was used to analyze the correlation between the number of roots and sex. RESULTS: Among the 392 teeth, 86.5% (n = 339) had 1 root; 45.4% (n = 178) of the teeth had 1 root canal, and 54.3% (n = 213) had 2 root canals that ranged from type II-type V. The majority of teeth with 2 root canals showed a type IV canal configuration (n = 79, 20.2%) followed by type II (n = 64, 16.3%), type III (n = 45, 11.4%), and type V (n = 25, 6.4%). Only 1 tooth had 3 root canals. No significant difference was found between the number of roots and sex (P > .05). Among the 213 teeth with 2 root canals, the most frequent distribution of the distance between the root canal orifice and the anatomic apex was 5-10 mm (n = 157). The distance between the 2 orifices of 189 teeth was 1-4 mm. CONCLUSIONS: The frequency of teeth with 2 root canals was high in maxillary second premolars. The internal morphology of teeth with 2 root canals was variable. This study provided useful information about the root canal morphology of maxillary second premolars in a Chinese subpopulation.

A study of the root canal morphology of mandibular anterior teeth using cone-beam computed tomography in a Chinese subpopulation.

INTRODUCTION: The purpose of this study was to investigate the root canal configuration of the mandibular anterior teeth using cone-beam computed tomographic (CBCT) imaging in a Chinese subpopulation. METHODS: A total of 3,871 CBCT images of mandibular anterior teeth were collected from 648 patients who accepted CBCT projection as a preoperative assessment for implants or orthodontic treatment. The following items were recorded and evaluated: tooth position, root number, canal number, root canal type, the distance between the anatomic apex and the point at which the canal divided into 2 for mandibular anterior teeth with 2 root canals (excluding canines with 2 roots), and the distance between the 2 root canal orifices. The Fisher exact test was used to analyze the correlation between the number of root canals and tooth position. RESULTS: All of the incisors in this study had 1 root, and 1.32% of the canines had 2 roots. The prevalence of 2 root canals in the lateral incisors (354, 27.36%) was higher than that in the central incisors (202, 15.71%) (P < .05) and the canines (81, 6.27%) (P < .05). CONCLUSIONS: There is a high prevalence of 2 root canals in the mandibular anterior teeth of the studied Chinese subpopulation. This study provides detailed information about the root canal morphology of mandibular anterior teeth in a Chinese subpopulation.