Ecological impact of surfactant Tween-80 on plankton: High-scale analyses reveal deeper hazards.

The ecological risks of surfactants have been largely neglected because of their low toxicity. Multiscale studies have indicated that even if a pollutant causes no acute toxicity in a test species, it may alter interspecific interactions and community characteristics through sublethal impacts on test organisms. Therefore, we investigated the lethal and sublethal responses of the plankton species Scenedesmus quadricauda, Chlorella vulgaris, and Daphnia magna, to surfactant Tween-80. Then, high-scale responses in grazer life-history traits and stability of the D. magna-larval damselfly system were further explored. The results showed that discernible adverse effects on the growth or survival of the three plankton species were evident only at exceptionally high concentrations (≥100 mg L-1). However, 10 mg L-1 of Tween-80 notably affected the MDA concentration in grazer species, simultaneously displaying a tendency to diminish grazer's heartbeat and swimming frequency. Furthermore, Tween-80 reduced the grazer reproductive capacity and increased its predation risk by larval damselflies, which ultimately jeopardized the stability of the D. magna-larval damselfly system at much lower concentrations (10-100 fold lower) than the individual-scale responses. This study provides evidence that high-scale traits are far more sensitive to Tween-80, compared with individual-scale traits for plankton organisms, suggesting that the ecological risks of Tween-80 demand careful reassessment. SYNOPSIS: The concentration of Tween-80 needed to induce changes in community characteristics is markedly lower than that needed to produce individual-scale consequences. Thus, high-scale analyses have broad implications for understanding the hazardous effects of surfactants compared with an individual-scale analysis.

Cryogenically cooled Fe:ZnSe-based chirped pulse amplifier at 4.07†µm.

A femtosecond chirped pulse amplifier based on cryogenically cooled Fe:ZnSe was demonstrated at 333 Hz-33 times higher than previous results achieved at near-room-temperature. The long upper-state lifetime allows free-running, diode-pumped Er:YAG lasers to be used as pump lasers. 250-fs, 4.59-mJ pulses are produced with a center wavelength of 4.07 µm, which avoids strong atmospheric CO2 absorption that cuts on around 4.2 µm. It is therefore possible to operate the laser in ambient air with good beam quality. By focusing the 18-GW beam in air, harmonics up to the ninth order were observed indicating its potential for use in strong-field experimentation.

Research progress on the pathogenicity of Porphyromonas gingivalis clinical strains / 口腔疾病防治

@#Porphyromonas gingivalis (P. gingivalis) is closely related to the occurrence and development of periodontitis. It is considered to be one of the important pathogens leading to alveolar bone resorption. At present, research on P. gingivalis mostly adopts standard laboratory strains whose genetic characteristics have been confirmed, are guaranteed and are traceable, such as ATCC 33277. The virulence phenotypes (endotoxin, firmbria, etc.) of clinically extracted isolates are quite different from those of standard strains, and the pathogenic effects and ability of the host are also widely different. In addition, P. gingivalis is considered to have a significant correlation with a variety of systemic diseases, and the virulence characteristics and pathogenic ability of different strains will have different effects on systemic diseases. However, at present, there is a lack of research on clinical strains and standard strains, and there is a lack of systematic comparison between the two sources of bacteria. In this paper, the differences in the virulence phenotypes and pathogenic effects between clinical isolates and standard strains of P. gingivalis in the last 5-10 years are reviewed. The aim is to elucidate the important virulence gene loci in the P. gingivalis gene sequence, which will play an important role in improving therapeutic methods and the development of related drugs.

Dental calculus: A repository of bioinformation indicating diseases and human evolution.

Dental calculus has long been considered as a vital contributing factor of periodontal diseases. Our review focuses on the role of dental calculus as a repository and discusses the bioinformation recently reported to be concealed in dental calculus from three perspectives: time-varying oral condition, systemic diseases, and anthropology at various times. Molecular information representing an individual's contemporary oral health status could be detected in dental calculus. Additionally, pathogenic factors of systemic diseases were found in dental calculus, including bacteria, viruses and toxic heavy metals. Thus, dental calculus has been proposed to play a role as biological data storage for detection of molecular markers of latent health concerns. Through the study of environmental debris in dental calculus, an overview of an individual's historical dietary habits and information about the environment, individual behaviors and social culture changes can be unveiled. This review summarizes a new role of dental calculus as a repository of bioinformation, with potential use in the prediction of oral diseases, systemic diseases, and even anthropology.

A Dentin Biomimetic Remineralization Material with an Ability to Stabilize Collagen.

The integrity of collagen matrix structure is a prerequisite for effectively inducing biomimetic remineralization. Repeated low pH stimulation activates matrix metalloproteinases (MMPs) in dental caries. Activated MMPs cause the breakdown of collagen fibrils. Collagen stabilization is a major obstacle to the clinical application of remineralization templates. Here, galardin-loaded poly(amido amine) (PAMAM)-NGV (PAMAM-NGV@galardin, PNG) is constructed to induce collagen stabilization and dentin biomimetic remineralization simultaneously, in order to combat early caries in dentin. PAMAM acts in the role of nucleation template for dentin remineralization, while galardin acts as the role of MMPs inhibitor. NGV peptides modified on the surface of dendrimer core can form small clusters with synergistic movement in short range, and those short-range clusters can form domain areas with different properties on the surface of PAMAM core and restrict the movement of collagen, favoring collagen crosslinking, which can be explained through the computational simulation analysis results. NGV peptides and galardin show a dual collagen-protective effect, laying the foundation for the dentin remineralization effect induced by PAMAM. PNG induces dentin remineralization in an environment with collagenase, meanwhile showsing anti-dentin caries efficacy in vivo. These findings indicate that PNG has great potential to combat early dentin caries for future clinical application.

Effects of artificial honey and epigallocatechin-3-gallate on streptococcus pyogenes.

BACKGROUND: Streptococcus pyogenes is an important global human pathogen that causes pharyngitis, and antibacterial therapy has become an important part of the overall therapy for pharyngitis. As natural derivatives, honey and green tea are often recommended for patients with pharyngitis in traditional Chinese medicine without experimental theoretical basis on wether the combined effect of honey and green tea on pharyngitis is better than they alone. The aims of this study were to explore the effects of artificial honey (AH) and epigallocatechin-3-gallate (EGCG) on S. pyogenes and elucidate the possible mechanisms, which were investigated using MIC (the minimum inhibitory concentration), FIC (fractional inhibitory concentration) index, growth pattern, biofilm formation and RT-qPCR. RESULTS: The MIC of AH on S. pyogenes was 12.5% (v/v) and the MIC of EGCG was 1250 µg/ml. The FIC index of AH and EGCG was 0.5. The planktonic cell growth, growth pattern and biofilm formation assays showed that AH and EGCG mixture had stronger inhibitory effect on S. pyogenes than they alone. RT-qPCR confirmed that the expression of hasA and luxS gene were inhibited by AH and EGCG mixture. CONCLUSIONS: AH and EGCG mixture can inhibit the planktonic cell growth, biofilm formation and some virulence genes expression of S. pyogenes, better than they alone. The combination of honey and green tea have the potential to treat pharyngitis as natural derivatives, avoiding drug resistance and double infection.

Corynebacterium matruchotii: A Confirmed Calcifying Bacterium With a Potentially Important Role in the Supragingival Plaque.

Corynebacterium matruchotii is a reported calcifying bacterium that can usually be isolated from dental calculus and induce mineralization in vitro. In recent years, based on in situ hybridization probe and sequencing technology, researchers have discovered the central "pillar" role of C. matruchotii in supragingival plaque, and many studies focused on bacterial interactions in the biofilm structure dominated by C. matruchotii have been conducted. Besides, C. matruchotii seems to be an indicator of "caries-free" oral status according to imaging and sequencing studies. Therefore, in this review, we summarize C. matruchotii 's role in supragingival plaque based on the structure, interactions, and potential connections with oral diseases.

Characterization of Bacterial Differences Induced by Cleft-Palate-Related Spatial Heterogeneity.

Background: Cleft palate (CP) patients have a higher prevalence of oral and respiratory tract bacterial infections than the general population. Nevertheless, characteristics of bacterial differences induced by CP-related anatomical heterogeneity are unknown. Methods: In this study, we systematically described the characteristics of bacteria in the oral and nasal niches in healthy children, CP children, healthy adolescents, CP adolescents, and postoperative adolescents by 454-pyrosequencing technology (V3−V6) to determine bacterial differences induced by CP. Results: Due to the CP-induced variations in spatial structure, the early establishment of microecology in CP children was different from that in healthy children. Nasal bacterial composition showed greater changes than in the saliva. Moreover, such discrepancy also appeared in CP and postoperative adolescents who had even undergone surgery > 10 years previously. Interestingly, we found by Lefse analysis that part of bacterial biomarkers in the nasal cavity of CP subjects was common oral flora, suggesting bacterial translocation between the oral and nasal niches. Therefore, we defined the oral−nasal translocation bacteria as O-N bac. By comparing multiple groups, we took the intersection sets of O-N bacs selected from CP children, CP adolescents, and postoperative adolescents as TS O-N bacs with time−character, including Streptococcus, Gemella, Alloprevotella, Neisseria, Rothia, Actinomyces, and Veillonella. These bacteria were at the core of the nasal bacterial network in CP subjects, and some were related to infectious diseases. Conclusions: CP would lead to significant and long-term differences in oral and nasal flora. TS O-N bacs migrating from the oral to the nasal might be the key stone causing nasal flora dysbiosis in the CP patients.

Efficient generation of femtosecond millijoule pulses at 3.1†µm.

3.2-mJ, 92-fs pulses centered at 3.1 µm are generated at a 1-kHz repetition rate through a tabletop optical parametric chirped pulse amplification (OPCPA) system based on ZnGeP2 crystals. Pumped by a 2-µm chirped pulse amplifier with a flat-top beam profile, the amplifier achieves a 16.5% overall efficiency, which, to the best of our knowledge, is the highest efficiency achieved by OPCPA at this wavelength. Harmonics up to the seventh order are observed after focusing the output in the air.

Application of poly(lactic-co-glycolic acid) in the treatment of pulp diseases / 口腔疾病防治

@#The development of materials science is of great significance to the treatment of dental pulp diseases. Poly lactic acid glycolic acid (PLGA) copolymer is an organic macromolecule compound that is widely used in the preparation of biomedical materials. In recent years, PLGA, as a drug/molecular loaded system and tissue regeneration scaffold, has shown prospects for application in the treatment of dental pulp diseases. This paper will review the application of PLGA in the treatment of dental pulp diseases and provide a basis for its further development and utilization. The results of the literature review show that PLGA is a drug/molecular delivery system that is mainly used in the improvement of pulp capping materials, root canal disinfectant and apexification materials. PLGA-improved pulp capping agents can prolong the action time of the drug and reduce toxicity. The modified root canal disinfectant can realize the sustained release of drug, make the drug penetrate deeper into the subtle structure, and contact more widely with the pathogenic bacteria. The modified apexification materials can provide more convenient administration methods for apexifixment. As a scaffold for tissue engineering, PLGA is mainly used in the study of pulp regeneration. The optimization of PLGA physical properties and action environment can provide a more suitable microenvironment for seed cells to proliferate and differentiate. How to utilize the advantages of PLGA to develop a more suitable material for endodontic application needs further study.

Generation of few-cycle multi-millijoule 2.5 µm pulses from a single-stage Cr2+:ZnSe amplifier.

Lasers capable of generating attosecond X-ray pulses in the water window (282 to 533 eV) through high-order harmonic generation are normally based on inefficient, multi-stage optical parametric amplifiers or optical parametric chirped pulse amplifiers pumped by femtosecond or picosecond lasers. Here we report a very efficient single amplification stage laser based on traditional chirped pulse amplification capable of producing 4 mJ, near-transform limited 44 fs (<6 cycles), 1 kHz pulses centered at 2.5 µm. The ≈90 GW peak power is the highest value ever reached at this wavelength. In order to fully compress the laser pulses our system is built in a nitrogen box. Our system utilizes water cooled chromium doped zinc selenide (Cr2+:ZnSe) as the gain medium and is pumped by a commercial nanosecond holmium doped yttrium-aluminum-garnet (Ho:YAG) laser.

Factors associated with the publication outcomes of paediatric proceedings presented at 2010-2016 the International Associations for Dental Research annual meetings.

The International Associations for Dental Research (IADR) annual meeting is one of the most important dental meetings throughout the world, and researches about paediatric dentistry presented in this platform are often used to guide clinical work. To evaluate the publication outcomes of oral and poster paediatric proceedings, which were accepted by the International Associations for Dental Research (IADR), annual meetings from 2010 to 2016 and to analyse the possible factors influencing an abstract's progression to publication. Oral and poster abstracts were retrieved from the official website of IADR (2010-2016). Searching for subsequent publications was conducted in PubMed and Google Scholar (up to March 2019). Two authors independently selected studies, collected, and analysed data. A total of 1396 abstracts were identified, including 275 oral presentations and 1121 poster presentations. Finally, 606 were published in peer-reviewed journals, with a publication rate of 43.41%. Abstracts were published earlier if it is from Europe, well funded, presented orally, or with large sample size. The high publication rate of the IADR proceedings supported the impact of IADR annual meetings on paediatric dentistry in the last 10 years.

Materials for pulpotomy in immature permanent teeth: a systematic review and meta-analysis.

BACKGROUND: Pulpotomy is one of the most widely used methods in preserving vital pulp in teeth, which is of great significance in achieving continue root formation in immature permanent teeth suffering from dental caries or trauma. The aim of this meta-analysis and systemic review is to synthesize the available evidences to compare different pulpotomy dressing agents for pulpotomy treatment in immature permanent teeth. METHODS: Electronic databases including MEDLINE (via Pubmed), EMBASE, the Cochrane library (CENTRAL) and the clinicaltrials.gov database were searched. The references of all included articles or relevant reviews were cross-checked. Only randomized controlled trials (RCTs) comparing two or more pulp dressing agent in permanent teeth with open apex would be included. Also, the studies should have at least 6 months of follow-up, report clinical and radiographic success in detail and publish in English. RESULTS: Five RCTs were included for a systematic review, and all of them had a high risk of bias. There is little difference in success rate between mineral trioxide aggregate (MTA) and calcium hydroxide (CH) at 6-month follow-up (risk ratio (RR) 1; 95% confidence interval (CI) 0.94 to 1.06) and 12-month follow-up (RR 1.04; 95% CI 0.96 to 1.13). There is no difference between MTA versus platelet-rich fibrin and MTA versus calcium-enriched mixture (CEM). There is only weak evidence of increased success rate in using MTA and triple antibiotic paste (TAP) rather than abscess remedy. CONCLUSIONS: Based on the present evidence, similar success rates with MTA were found between the dressing agents CH, CEM, RPF and TAP as pulpotomy-dressing agents in the treatment of immature permanent teeth. More high-quality RCTs are needed in this field in future studies.

Non-syndromic occurrence of true generalized microdontia with hypodontia: A case report.

RATIONAL: Dental abnormalities can occur at any stage of tooth development. Of these abnormalities, true generalized microdontia is a rare condition in which all teeth are smaller than normal, while hypodontia is defined as the absence of 1 to 5 teeth. As far as we are aware, no article has reported a case of the non-syndromic occurrence of true generalized microdontia with hypodontia. PATIENT CONCERNS: A 9-year-old girl who had no systemic diseases presented with congenital absence of maxillary lateral incisors bilaterally and small teeth involving the whole dentition. DIAGNOSES: Based on intraoral examinations and panoramic radiograph, the patient was diagnosed with the simultaneous occurrence of true generalized microdontia, hypodontia, and a variation of maxillary 1st molar with a single root and single canal. Also, the patient had premature loss of mandibular molars and canines, periapical periodontitis in the mandible left 1st primary molar and deep caries in mandible left secondary primary molar. INTERVENTIONS: A removable appliance to hold space for early loss of mandibular molars and canines was made at the present stage. The mandible left 1st primary molar had periapical periodontitis and the affected tooth was extracted. Furthermore, the distal surface of the mandible left 2nd primary molar was filled with complex resin materials. A multi-disciplinary therapy plan was carefully designed including orthodontics, dental implants and esthetic restoration in the future. OUTCOMES: The patient complied well with instructions for wearing the removable space maintainer, which helps prevent mesial migration of the permanent 1st molars, at the current stage. The therapeutic efficiency on periapical periodontitis and caries lesions was also good. LESSONS: The non-syndromic presence of true generalized microdontia is extremely rare. A personalized treatment plan with multi-disciplinary considerations should be given for these patients. The pathogenesis remains unclear but may be related to genetic as well as environmental factors. More studies are urgently needed to explore the pathogenesis and treatment options for the future.