Morphology and classification of the second mesiobuccal canal in maxillary first molars: a cone-beam computed tomography analysis in a Chinese population.

BACKGROUND: Understanding the tooth anatomy is crucial for ensuring effective endodontic treatment. This study investigated the root canal morphology of the second mesiobuccal (MB2) canal in maxillary first molars (MFMs) in a Chinese population using cone-beam computed tomography (CBCT). METHODS: This study evaluated 486 MFMs with MB2 canals from 285 participants undergoing CBCT examination and determined the Vertucci's classification and position of the MB2 canal orifice. The prevalence of the MB2 canal was correlated with the sex, age, and tooth side. The correlations between the prevalence of the MB2 canal and sex and tooth side were assessed using the Fisher's exact test. The chi-square test was used for evaluating the correlation between the prevalence of the MB2 canal and age. RESULTS: The number of type II, III, IV, V, VI, VII, and other root canals in the MFMs was 30.9%, 0.6%, 65.0%, 1.2%, 1.2%, 0.4%, and 0.6%, respectively. Among the 201 cases with bilateral inclusion, 87.6% showed consistent canal configuration. Results of the first clear apparent position (FCAP) of the MB2 canals showed that 434, 44, and 3 teeth had FCAP at the upper, middle, and bottom one-third of the root, respectively. The FCAPs of the MB2 canal in the MFMs with types II, IV, and VI, as well as types III and V canals showed significant differences (p<0.05). The horizontal distance between the MB1 and MB2 canal orifices in the type II canals of MFMs was significantly lesser than those in the type IV canals of MFMs (p < 0.01). The longitudinal distance between the pulp chamber floor plane and MB2 canal orifice significantly correlated with age (p < 0.05). CONCLUSIONS: The morphology of the mesiobuccal root canal in the MFMs is complex. Complete understanding of the anatomical morphology of the root canal combined with the CBCT and dental operating microscope is necessary for the accurate detection of the MB2 canal and consequently improved success rate of root canal treatment. Our study findings can help endodontists improve endodontic treatment outcomes.

Wnt5a-Ror2 signaling mediates root resorption.

INTRODUCTION: This study aimed to investigate the role of wingless-type MMTV integration site family member 5a (Wnt5a)-receptor tyrosine kinase-like orphan receptor 2 (Ror2) signaling in root resorption. METHODS: The messenger RNA (mRNA) expression of Wnt5a, Ror2, and RANKL in periodontal ligament cells (PDLCs) under compression force (CF) with or without Ror2 small interfering RNA (siRNA) were measured by quantitative reverse transcription-polymerase chain reaction, and these proteins released into culture supernatants were measured using enzyme-linked immunosorbent assay. Then these PDLC-conditioned media under CF with or without Ror2 siRNA were used to culture osteoclast precursors to detect osteoclastogenesis effects via tartrate-resistant acid phosphatase staining. In in vivo studies, the odontoclast number and the root resorption volume under excessive CF with or without Ror2 siRNA were investigated by tartrate-resistant acid phosphatase immunohistochemical staining and microcomputed tomography. The protein levels for Wnt5a, Ror2, and receptor activator of nuclear factor-kappa B ligand (RANKL) in the periodontal ligament tissues were also detected using immunohistochemical staining. Finally, the odontoclast number, root resorption volume, and the mRNA and protein expressions were compared between immature and mature teeth. RESULTS: The mRNA production and protein release level of Wnt5a, Ror2, and RANKL increased after CF, whereas they were significantly downregulated with Ror2 siRNA. The osteoclast number increased treating with culture medium from PDLC applying CF, but the increase was inhibited after adding Ror2 siRNA. In the animal model, the odontoclast number and root resorption volume significantly increased in the CF group but decreased in the CF with the Ror2 siRNA group. The protein levels of Wnt5a, Ror2, and RANKL in periodontal ligament were upregulated under excessive CF, and the pathway was inhibited with Ror2 siRNA. In the immature tooth group, the odontoclast number, root resorption volume, and the mRNA and protein expressions of Wnt5a-Ror2 signaling were reduced. CONCLUSIONS: Wnt5a-Ror2 signaling in PDLCs enhanced by excessive CF could promote RANKL release and induce precursor differentiation, partly leading to increased odontoclast activity and ultimate root resorption. The less resorption of the immature tooth may be due to odontoclastogenesis inhibition by decreased expression of Wnt5a-Ror2 signaling.

Long non-coding RNAs: Emerging roles in periodontitis.

Periodontitis is a major burden of public health, affecting 20%-50% of the global population. It is a complex inflammatory disease characterized by the destruction of supporting structures of the teeth, leading to tooth loss and the emergence or worsening of systematic diseases. Understanding the molecular mechanisms underlying the physiopathology of periodontitis is beneficial for targeted therapeutics. Long non-coding RNAs (lncRNAs), transcripts made up of more than 200 nucleotides, have emerged as novel regulators of many biological and pathological processes. Recently, an increasing number of dysregulated lncRNAs have been found to be implicated in periodontitis. In this review, an overview of lncRNAs, including their biogenesis, characteristics, function mechanisms and research approaches, is provided. And we summarize recent research reports on the emerging roles of lncRNAs in regulating proliferation, apoptosis, inflammatory responses, and osteogenesis of periodontal cells to elucidate lncRNAs related physiopathology of periodontitis. Furthermore, we have highlighted the underlying mechanisms of lncRNAs in periodontitis pathology by interacting with microRNAs. Finally, the potential clinical applications, current challenges, and prospects of lncRNAs as diagnostic and prognostic biomarkers and therapeutic targets for periodontitis disease are discussed.

Regulating the Supramolecular Polymerization of Fibrous Crystalline Structures in Aqueous Solution.

Inspired by protein polymerizations, much progress has been made in making "polymer-like" supramolecular structures from small synthetic subunits through non-covalent bonds. A few regulation mechanisms have also been explored in synthetic platforms to create supramolecular polymers and materials with dynamic properties. Herein, a type of reactive regulator that facilitates the dimerization of the monomer precursors through dynamic bonds to trigger the supramolecular assembly from small molecules in an aqueous solution is described. The supramolecular structures are crystalline in nature and the reaction coupled assembly strategy can be extended to a supramolecular assembly of aromatic amide derivatives formed in-situ. The method may be instructive for the development of supramolecular nanocrystalline materials with desired physical properties.

Multiple root canals in the maxillary molar: an unusual case report.

BACKGROUND: The objective of this report was to highlight the importance of using a dental operating microscope (DOM) to locate supernumerary canals and diagnose variations in root canals using cone-beam computed tomographic (CBCT) images. CASE PRESENTATION: A 35-year-old Chinese female had repeated swelling in the upper right posterior maxilla for 3 months and was referred to evaluate symptomatic apical periodontitis and mesotaurodonts for upper right first permanent molar and upper right second permanent molar. Root canal therapy was proposed and conducted with the use of DOM and CBCT. CONCLUSIONS: Proper diagnosis and careful clinicoradiological examination are necessary, and it is essential to reinforce the knowledge of the rare morphology of root canals for clinicians.

DNA-Mediated Step-Growth Polymerization of Bottlebrush Macromonomers.

Herein, we report the DNA-mediated self-assembly of bivalent bottlebrush polymers, a process akin to the step-growth polymerization of small molecule monomers. In these "condensation reactions", the polymer serves as a steric guide to limit DNA hybridization in a fixed direction, while the DNA serves as a functional group equivalent, connecting complementary brushes to form well-defined, one-dimensional nanostructures. The polymerization was studied using spectroscopy, microscopy, and scattering techniques and was modeled numerically. The model made predictions of the degree of polymerization and size distribution of the assembled products, and suggested the potential for branching at hybridization junctions, all of which were confirmed experimentally. This study serves as a theoretical basis for the polymer-assembly approach which has the potential to open up new possibilities for suprapolymers with controlled architecture, macromonomer sequence, and end-group functionalities.

Treatment of Lung Cancer by Peptide-Modified Liposomal Irinotecan Endowed with Tumor Penetration and NF-κB Inhibitory Activities.

Current chemotherapy for lung cancer achieved limited efficacy due to poor tumor targeting and tissue penetration. Another obstacle in the therapy is activated nuclear factor-κB (NF-κB) in tumor cells, which plays a crucial role in promotion of antiapoptosis and drug resistance. In this study, we utilized a multifunctional liposome loaded with irinotecan and surface modified with a cell-permeable NF-κB inhibitor (CB5005), for treatment of non-small-cell lung carcinoma. CB5005 downregulated the level of NF-κB-related protein in the nuclei of A549 cells, and increased cellular uptake of the modified liposomes. In vivo antitumor activity in mice bearing A549 xenografts revealed that modification with CB5005 significantly improved the tumor inhibition rate of irinotecan. Immunohistochemical assays showed that the tumors treated with CB5005-modified liposomes possessed the most apoptotic cells and the lowest level of p50 in the cell nuclei. These results strongly suggest that antitumor efficacy of the irinotecan liposomes can be enhanced by tumor-penetrating and NF-κB-inhibiting functions of CB5005. Consequently, CB5005-modified liposomes provide a possible synergistic therapy for lung cancer, and would also be appropriate for other types of tumors associated with elevated NF-κB activity.

Peptide-Based Autophagic Gene and Cisplatin Co-delivery Systems Enable Improved Chemotherapy Resistance.

Cisplatin-based chemotherapy is a widely used first-line strategy for numerous cancers. However, drug resistances are often inevitable accompanied by the long-term use of cisplatin in vivo, significantly hampering its therapeutic efficacy and clinical outcomes. Among others, autophagy induction is one of the most common causes of tumor resistance to cisplatin. Herein, a self-assembled nanoprodrug platform was developed with the synergistic effect of cisplatin and RNAi to fight against cisplatin-resistant lung cancer. The nanoprodrug platform consists of three molecular modules, including prodrug complex of Pt(IV)-peptide-bis(pyrene), DSPE-PEG, and cRGD-modified DSPE-PEG. The Pt(IV) is immobilized with peptide via amide bonds, allowing the Pt(IV) to be loaded with a loading efficiency of >95% and rapid-release active platinum ions (Pt(II)) in the presence of glutathione (GSH). Meanwhile, the peptide of the prodrug complex could efficiently deliver Beclin1 siRNA ( Beclin1 is an autophagy initiation factor) to the cytoplasm, thereby leading to autophagy inhibition. In addition, incorporation of DSPE-PEG and cRGD-modified DSPE-PEG molecules improves the biocompatibility and cellular uptake of the nanoprodrug platform. In vivo results also indicate that the nanoprodrug platform significantly inhibits the growth of a cisplatin-resistant tumor on xenograft mice models with a remarkable inhibition rate, up to 84% after intravenous injection.

Secondary structures in synthetic polypeptides from N-carboxyanhydrides: design, modulation, association, and material applications.

Synthetic polypeptides derived from the ring-opening polymerization of N-carboxyanhydrides can spontaneously fold into stable secondary structures under specific environmental conditions. These secondary structures and their dynamic transitions play an important role in regulating the properties of polypeptides in self-assembly, catalysis, polymerization, and biomedical applications. Here, we review the current strategies to modulate the secondary structures, and highlight the conformation-specific dynamic properties of synthetic polypeptides and the corresponding materials. A number of mechanistic studies elucidating the role of secondary structures are discussed, aiming to provide insights into the new designs and applications of synthetic polypeptides. We aim for this article to bring to people's attention synthetic polymers with ordered conformations, which may exhibit association behaviors and material properties that are otherwise not found in polymers without stable secondary structures.

Polymer-KLAK Peptide Conjugates Induce Cancer Cell Death through Synergistic Effects of Mitochondria Damage and Autophagy Blockage.

Nanoscaled polymer-peptide conjugates (PPCs) containing both functional peptides and synthetic polymer comprise a new family of biomaterials that can circumvent the limitation of peptides alone. Our previous work showed that PPCs with the therapeutic peptide KLAK, especially PPCs with shorter PEG spacers and a higher degree of polymerization, exhibit enhanced antitumor effects through disrupting mitochondrial membranes. However, as PPCs have a spherical nanostructure (45-60 nm), this may have other effects besides the conjugated therapeutic peptide KLAK itself when they enter cancer cells. In this research, we compared the proteome differences of U87 cells treated with KLAK, polymer, and their conjugates (P-KLAK) through quantitative proteomics technology. The result reveals that proteins involved in oxidative stress response and the Nrf2/ARE pathway were significantly up-regulated after P-KLAK treatment. Moreover, the overexpression of sequestosome 1, a protein substrate that is selectively incorporated into the formation of autophagosome and degraded by autophagy, is found in our study and has not been reported previously in the study of KLAK toxicity. Additional experiments suggest that upon endocytosis, P-KLAK causes lysosome impairment and results in autophagosomes accumulation. Hence, P-KLAK might induce U87 cell death by autophagy blockage due to lysosome impairment as well as mitochondria damage synergistically.

pH-Sensitive Polymeric Nanoparticles Modulate Autophagic Effect via Lysosome Impairment.

In drug delivery systems, pH-sensitive polymers are commonly used as drug carriers, and significant efforts have been devoted to the aspects of controlled delivery and release of drugs. However, few studies address the possible autophagic effects on cells. Here, for the first time, using a fluorescent autophagy-reporting cell line, this study evaluates the autophagy-induced capabilities of four types of pH-sensitive polymeric nanoparticles (NPs) with different physical properties, including size, surface modification, and pH-sensitivity. Based on experimental results, this study concludes that pH-sensitivity is one of the most important factors in autophagy induction. In addition, this study finds that variation of concentration of NPs could cause different autophagic effect, i.e., low concentration of NPs induces autophagy in an mTOR-dependent manner, but high dose of NPs leads to autophagic cell death. Identification of this tunable autophagic effect offers a novel strategy for enhancing therapeutic effect in cancer therapy through modulation of autophagy.

Enzymatic Activities of Polycatalytic Complexes with Nonprocessive Cellulases Immobilized on the Surface of Magnetic Nanoparticles.

Polycatalytic enzyme complexes made by immobilization of industrial enzymes on polymer- or nanoparticle-based scaffolds are technologically attractive due to their recyclability and their improved substrate binding and catalytic activities. Herein, we report the synthesis of polycatalytic complexes by the immobilization of nonprocessive cellulases on the surface of colloidal polymers with a magnetic nanoparticle core and the study of their binding and catalytic activities. These polycatalytic cellulase complexes have increased binding affinity for the substrate. But due to their larger size, these complexes were unable to access to the internal surfaces of cellulose and have significantly lower binding capacity when compared to those of the corresponding free enzymes. Analysis of released soluble sugars indicated that the formation of complexes may promote the prospect of having consistent, multiple attacks on cellulose substrate. Once bound to the substrate, polycatalytic complexes tend to remain on the surface with very limited mobility due to their strong, multivalent binding to cellulose. Hence, the overall performance of polycatalytic complexes is limited by its substrate accessibility as well as mobility on the substrate surface.

pH-Sensitive Polymeric Nanoparticles with Gold(I) Compound Payloads Synergistically Induce Cancer Cell Death through Modulation of Autophagy.

Various nanomaterials have been demonstrated as autophagy inducers owing to their endocytosis cell uptake pathway and impairment of lysosomes. pH-dependent nanomaterials as drug delivery systems that are capable of dissociating in weakly acidic lysosomal environment (pH 4-5) and consequently releasing the payloads into the cytoplasm have been paid extensive attention, but their autophagy-modulating effects are less reported so far. In this study, we report pH-sensitive micelle-like nanoparticles (NPs) that self-assembled from poly(ß-amino ester)s to induce cell autophagy. By encapsulation of gold(I) compounds (Au(I)) into hydrophobic domains of NPs, the resultant Au(I)-loaded NPs (Au(I)⊂NPs) shows synergistic cancer cell killing performance. The Au(I)⊂NPs enter cells through endocytosis pathway and accumulate into acidic lysosomes. Subsequently, the protonation of tertiary amines of poly(ß-amino ester)s triggers the dissociation of micelles, damages the lysosomes, and blocks formation of autolysosomes from fusion of lysosomes with autophagosomes. In addition, Au(I) preferentially inhibits thioredoxin reductase (TrxR) in MCF-7 human breast cancer cells that directly links to up-regulate reactive oxygen species (ROS) and consequently induce autophagy and apoptosis. The blockade of autophagy leads to excessive depletion of cellular organelles and essential proteins and ultimately results in cell death. Therefore, pH-sensitive polymeric nanoparticles with gold(I) compound payloads can synergistically induce cancer cell death through regulation of autophagy. Identification of the pH-sensitive nanomaterials for synergistically inducing cell death through regulation autophagy may open a new avenue for cancer therapy.

Enhancing antitumor immunity with stimulus-responsive mesoporous silicon in combination with chemotherapy and photothermal therapy.

Due to the immunosuppressive tumor microenvironment (TME) and potential systemic toxicity, chemotherapy often fails to elicit satisfactory anti-tumor responses, so how to activate anti-tumor immunity to improve the therapeutic efficacy remains a challenging problem. Photothermal therapy (PTT) serves as a promising approach to activate anti-tumor immunity by inducing the release of tumor neoantigens in situ. In this study, we designed tetrasulfide bonded mesoporous silicon nanoparticles (MSNs) loaded with the traditional drug doxorubicin (DOX) inside and modified their outer layer with polydopamine (DOX/MSN-4S@PDA) for comprehensive anti-tumor studies in vivo and in vitro. The MSN core contains GSH-sensitive tetrasulfide bonds that enhance DOX release while generating hydrogen sulfide (H2S) to improve the therapeutic efficacy of DOX. The polydopamine (PDA) coating confers acid sensitivity and mild photothermal properties upon exposure to near-infrared (NIR) light, while the addition of hyaluronic acid (HA) to the outermost layer enables targeted delivery to CD44-expressing tumor cells, thereby enhancing drug accumulation at the tumor site and reducing toxic side effects. Our studies demonstrate that DOX/MSN@PDA-HA can reverse the immunosuppressive tumor microenvironment in vivo, inducing potent immunogenic cell death (ICD) of tumor cells and improving anti-tumor efficacy. In addition, DOX/MSN@PDA-HA significantly suppresses tumor metastasis to the lung and liver. In summary, DOX/MSN@PDA-HA exhibits controlled drug release, excellent biocompatibility, and remarkable tumor inhibition capabilities through synergistic chemical/photothermal combined therapy.

Dietary habits and nutrition status in esophageal cancer patients after esophageal reconstruction.

Background: Surgery is the cornerstone of the treatment of esophageal cancer (EC). This study is to evaluate the dietary habits and nutrition status in EC patients who underwent esophagectomy followed by esophageal reconstruction. Methods: This retrospective study included patients with EC who underwent esophagectomy followed by esophageal reconstruction in the Department of Thoracic Surgery I of Peking University Cancer Hospital between February 2014 and December 2018. The primary outcomes were dietary habits and nutrition status. The secondary outcomes were gastrointestinal symptoms and quality of life (QoL). Results: A total of 346 patients were included. At 30 months after the operation, 90.2% of the patients had recovered to regular dietary habits, 72.8% of patients had a restored frequency of preoperative regular food intake, 2.3% of the patients ate more than six times a day, and 0.6% had semi-liquid food because of bad teeth. The nutrition status remained stable after 6 months postoperatively and recovered slightly 1 year after the surgery. At 30 months after the operation, the most common gastrointestinal symptoms were reflux (38.4%), dysphagia (15.3%), hoarseness (11.8%), abdominal distension (6.6%), diarrhea (2.9%), and nausea and vomiting (2.3%). According to the European Organization for Research and Treatment of Cancer, Quality of Life Questionnaire-OG 25 (EORTC QLQ-OG 25), the factors that affected the life quality of patients during follow-up were anxiety, reflux, and dietary limitations. Conclusions: Most patients with EC who underwent esophageal reconstruction recovered to regular dietary habits and stable nutrition status, while some may still suffer from gastrointestinal symptoms, anxiety, and dietary limitations.

TGF-ß1/Smad3 Signaling Is Required to Alleviate Fluoride-Induced Enamel Hypomineralization.

Excessive fluoride intake during enamel development can affect enamel mineralization, leading to dental fluorosis. However, its potential mechanisms remain largely unexplored. In the present study, we aimed to investigate the impact of fluoride on the expressions of RUNX2 and ALPL during mineralization and the effect of TGF-ß1 administration on fluoride treatment. A dental fluorosis model of newborn mice and an ameloblast cell line ALC were both used in the present study. The mice of the NaF group, including the mothers and newborns, were fed with water containing 150 ppm NaF after delivery to induce dental fluorosis. The mandibular incisors and molars showed significant abrasion in the NaF group. Immunostaining, qRT-PCR, and Western blotting analysis indicated that exposure to fluoride markedly down-regulated RUNX2 and ALPL in mouse ameloblasts and ALCs. Besides, fluoride treatment significantly decreased the mineralization level detected by ALP staining. Furthermore, exogenous TGF-ß1 up-regulated RUNX2 and ALPL and promoted mineralization, while the addition of SIS3 could block such TGF-ß1-induced up-regulation. In TGF-ß1 conditional knockout mice, the immunostaining of RUNX2 and ALPL was weaker compared with wild-type mice. Exposure to fluoride inhibited the expressions of TGF-ß1 and Smad3. Co-treatment of TGF-ß1 and fluoride up-regulated RUNX2 and ALPL compared with the fluoride alone treatment, promoting mineralization. Collectively, our data indicated that TGF-ß1/Smad3 signaling pathway was necessary for the regulatory effects of fluoride on RUNX2 and ALPL, and the fluoride-induced suppression of ameloblast mineralization was mitigated by activating TGF-ß1/Smad3 signaling pathway.

Systematic optimization of biochars derived from corn wastes, pineapple leaf, and sugarcane bagasse for Cu(II) adsorption through response surface methodology.

Many industrial wastewaters contain an appreciable amount of toxic copper (Cu(II)) that needs to be properly treated before discharging into receiving water body. Adsorption can effectively remove Cu(II) with optimized parameters. This study investigates the critical pyrolysis parameters of biochar derived from agricultural waste. Optimized biochar showed maximum Cu(II) adsorption capacity of 60.7, 36.8, and 35.5 mg g-1 by PLB, SBB, and CWB at pyrolysis temperatures of 555 ℃, 559 ℃, 507 ℃, respectively, compared with commercial activated carbon (CAC, 40.8 mg g-1). Surface characterization confirmed surface complexation, electrostatic interaction, and cation exchange capacity as Cu(II) removal mechanisms. The presence of humic acid reduced the Cu(II) removal of both CAC and optimized biochars. Optimized PLB displayed high reusability (87% Cu(II) removal efficiency) after five consecutive cycles using pressure cooker regeneration. With excellent Cu(II) adsorption capacity and reusability, the investigated biochars show high applicability potential to Cu(II)-laden wastewater treatment.

Periodontal Ligament Stem Cell-Derived Extracellular Vesicles Enhance Tension-Induced Osteogenesis.

Tension-induced osteogenesis has great significance in maintaining bone homeostasis and ensuring the efficiency and stability of orthodontic treatment. Recently, extracellular vesicles (EVs) have shown great potential in regulating bone remodeling. Here, we aimed to explore the effects of periodontal ligament stem cell (PDLSC)-derived EVs on tension-induced osteogenesis and the potential mechanism. PDLSC-derived EVs were extracted by ultracentrifugation. In vitro, PDLSC-derived EVs of 10 µg/mL significantly improved the proliferation of MC3T3-E1 cells and enhanced the osteogenic differentiation of osteoblasts under a tensile strain of 2000 uε. Next, a mouse model of orthodontic tooth movement (OTM) was established and treated with subperiosteal injection of PDLSC-derived EVs (1 mg/kg) on the tension side. The results showed that treatment with PDLSC-derived EVs effectively enhanced OTM and promoted osteogenesis on the tension side, including increasing trabecular bone parameters and promoting the expression of osteogenic-related biomarkers (OCN and OPN). More interestingly, we identified several mechano-sensitive miRNAs enriched in PDLSC-derived EVs by high-throughput miRNA sequencing. Bioinformatics analysis indicated that they were related to various osteogenesis-related signaling pathways. Therefore, PDLSC-derived EVs could improve the efficiency of OTM by enhancing tension-induced osteogenesis of osteoblasts. Our study may provide potential evidence for the promoting effects of PDLSC-derived EVs on osteogenesis and offer new insights into the development of treatment strategies for enhancing osteogenesis in orthodontic treatment and other metabolic bone diseases.

Clinical observation of autologous platelet rich fibrin assisted revascularization of mature permanent teeth.

OBJECTIVE: To investigate the clinical observation of autologous platelet-rich fibrin (PRF) assisting the revascularization of mature permanent teeth. METHODS: Twenty patients with mature permanent teeth were divided into experimental group and control group. The control group was treated with classic revascularization, and the experimental group was treated with PRF-assisted mature permanent tooth revascularization. RESULTS: After treatment, the total effective rate of the experimental group (100.00%) was higher than that of the control group (50.00%); the thickness of the root canal wall of the experimental group was higher than that of the control group, and the crown root length was lower than that of the control group; The bite degree, chewing function, color, overall aesthetic score, and satisfaction rate of the patients were higher, and the difference was statistically significant (P < 0.05). CONCLUSION: Autologous PRF assists in revascularization of mature permanent teeth, which can achieve ideal results, and promote pulp regeneration.

3D printed miniature atomic emission detector coupling with gas chromatography: A sensitive and cost-effective strategy for the determination of volatile methylsiloxanes in municipal sewage.

The determination of volatile methylsiloxanes (VMSs) in municipal sewage has attracted great attention. Gas chromatography-mass spectrometry (GC-MS) is the most mature detection technique for VMSs, however, its instrumentation and operation cost are unfavorable in low- and middle-income countries. Herein, a novel and cost-effective strategy by using a 3D printed miniature microplasma optical emission detector (µAED) as an alternative to MS detector, was developed to detect VMSs in municipal sewage by GC after preconcentration by a laboratory-built automatic purge and trap (P&T) system. Two types of µAEDs have been fabricated and their analytical performances were compared. The one using two tungsten rods as electrodes shows better performance and was thus selected as the detecting system for real sample analysis. Under the optimized conditions, the P&T-GC-µAED system provided limits of detection of 3.6 ng L-1 to 15.5 ng L-1 of Si for tested VMSs. Relative standard deviations were better than 3.0% and good recoveries ranging from 82.4% to 102.8% were obtained for all analytes. The applicability of this system was demonstrated via the measurement of VMSs in the influents and effluents from 10 wastewater treatment plants (WWTPs) in Chengdu, China.