Digital workflow for proximal adjustment of teeth adjacent to implant-supported fixed restorations using a predesigned computer-aided grinding guide.

Clinically, the proximal surfaces of teeth adjacent to an implant restoration usually need to be adjusted to build a preferable adjacency relationship. However, it is difficult for freehand preparation to get a favorable proximal contour in some cases. In the workflow presented here, virtual grinding can be made to adjacent teeth, under the consideration of functional reconstruction and biological requirements, and then the grinding can be implemented using digital templates and a specialized bur. This allows for more precise and accurate adjustments to be made during the clinical procedure, reducing the risk of over- or under-preparation of the proximal surfaces. In addition, the use of specialized diamond burs and grinding guides can make the procedure more efficient and streamlined, reducing the time required for proximal adjustment and minimizing patient discomfort. The resulting implant-supported prosthesis is more likely to function properly and last longer, as the precise proximal contacts can help distribute occlusal forces more evenly across the dentition. Overall, the use of digital technology for precise adjustment of proximal contacts during implant restorations represents an important advancement in modern dentistry, enabling dentists to provide their patients with more accurate, efficient, and effective dental care.

Investigation of the Adsorption of Sulfamethoxazole by Degradable Microplastics Artificially Aged by Chemical Oxidation.

In this study, three different types of microplastics were aged by the thermal activation K2S2O8 method to investigate the adsorption behavior for sulfamethoxazole (SMX) in aqueous solution. The effects of pH, salinity and humic acid (HA) on adsorption behavior were also investigated. At the same time, the morphology and functional groups of microplastics before and after adsorption were characterized. As the aging time increased, the adsorption capacity of the microplastics also increased significantly. Whether it was pristine or aged, polylactic acid (PLA) had the highest adsorption capacity. The adsorption capacity of microplastics was the largest under acidic conditions, and its adsorption capacity decreased significantly in alkaline solutions. The presence of salinity inhibited the adsorption of SMX on polyethylene terephthalate (PET) and PP, but the adsorption capacity of PLA increases when salinity was above 10‰. The adsorption of SMX on microplastics was promoted by HA. When the concentration of HA was 20 mg/L, the adsorption capacity of PLA and PET decreased. Kinetic and isotherm fits were applied to the adsorption process. The increase in sorption capacity was related to the development of holes and cracks and the enhanced number of surface oxygen-containing functional groups. The adsorption kinetics to pristine microplastics conformed to a pseudo-first-order kinetic model, while the kinetics of the aged microplastics conformed to a pseudo-second-order kinetic model. It implies that the adsorption of SMX by aging microplastics involves multiple processes. The adsorption isothermal adsorption process of SMX by microplastics accorded with Freundlich model, belonging to multi-layer adsorption.

Effects of Oil Droplet Size and Interfacial Protein Film on the Properties of Fish Myofibrillar Protein-Oil Composite Gels.

The effects of oil droplet size and the formation of an interfacial protein film (IPF) on silver carp myofibrillar protein (MP)-oil composite gels were studied. MP- or Tween 80-stabilized camellia seed oil emulsions with different droplet sizes were prepared and added to MPs to prepare composite gels. The oil droplet size of the Tween 80-stabilized emulsion was significantly smaller (p < 0.05) than that of the MP-stabilized emulsion with the same homogenization speed. However, polymerization of Tween 80-stabilized emulsions during the preparation of the composite gels was found. Composite gels with the MP-stabilized emulsions of a small droplet size showed significantly improved water-holding capacity, texture, and dynamic rheological properties. Interfacial shear rheology studies revealed that the storage modulus (G') of the MP-stabilized emulsion composite gels was higher than that of the Tween 80-stabilized gels, and the tan δ of the MP-stabilized oil emulsion composite gels was smaller than that of the Tween 80-stabilized gels, indicating that stronger elastic gel structures were formed. These results suggested that the IPF formed in the MP-stabilized emulsion helped stabilize the oil droplets embedded in the protein gel network, and the smaller the droplet size, the more stable the composite gel. This work provides a better understanding of how oil emulsions interact with protein and affect the properties of MP-oil composite gels.

Pollution characteristics and fate of microfibers in the wastewater from textile dyeing wastewater treatment plant.

Wastewater discharged from wastewater treatment plants (WWTPs) is suspected to be a significant contributor of microplastics (MPs) to the environment, and fiber is the main shape of MPs in wastewater effluent. A typical textile industry WWTP with 30,000 tons of daily treatment capacity was sampled for microfibers at different stages of the treatment process to ascertain at what stage in the treatment process the microfibers are being removed. The average abundance of microfibers was 334.1 (±24.3) items/litre in influent, and it reduced to 16.3 (±1.2) items/litre in the final effluent with a decrease of 95.1%. Despite this large reduction we calculated that this textile industry WWTP was releasing 4.89 × 108 microfibers including microplastic fibers and non-microplastic fibers into the receiving water every day. This study showed that a modest amount of microplastics being released per litre of effluent could result in significant amounts of fibers entering the environment, despite the fact that efficient removal rates of microplastic fibers and non-microplastic fibers were achieved by this modern treatment plant when dealing with such a large volume of effluent. The fate of fibers is described during the textile industry wastewater treatment process.

Assessing changes in quality of life using the Oral Health Impact Profile (OHIP) in patients with different classifications of malocclusion during comprehensive orthodontic treatment.

BACKGROUND: The objectives of this study were to investigated changes in OHRQoL among patients with different classifications of malocclusion during comprehensive orthodontic treatment. METHODS: Clinical data were collected from 81 patients (aged 15 to 24) who had undergone comprehensive orthodontic treatment. Participants were classified 3 groups: Class I (n = 35), II (n = 32) and III (n = 14) by Angle classification. OHRQoL was assessed using the Oral Health Impact Profile (OHIP-14). All subjects were examined and interviewed at baseline (T0), after alignment and leveling (T1), after correction of molar relationship and space closure (T2), after finishing (T3). Friedman 2-way analysis of variance (ANOVA) and Wilcoxon signed rank tests were used to compare the relative changes of OHRQoL among the different time points. A Bonferroni correction with P < 0.005 was used to declare significance. RESULTS: Significant reductions were observed in all seven OHIP-14 domains of three groups except for social disability (P > 0.005) in class I and class II, Handicap in class II and class III (P > 0.005). Class I patients showed significant changes for psychological disability and psychological discomfort domain at T1, functional limitation, physical pain at T2. Class III patients showed a significant benefit in all domains except physical pain and functional limitation. Class II patients showed significant changes in the physical pain, functional disability, and physical disability domains at T1. CONCLUSIONS: The impact of comprehensive orthodontic treatment on patients' OHRQoL do not follow the same pattern among patients with different malocclusion. Class II patients benefits the most from the stage of space closure, while class I patients benefits the first stage (alignment and leveling) of treatment in psychological disability and psychological discomfort domains.

Plasmid-encoding vasostatin inhibited the growth and metastasis of human hepatocellular carcinoma cells.

The growth and metastasis of solid tumors depends on angiogenesis. Anti-angiogenesis therapy may represent a promising therapeutic option. Vasostatin, the N-terminal domain of calreticulin, is a very potent endogenous inhibitor of angiogenesis and tumor growth. In this study, we attempted to investigate whether plasmid-encoding vasostatin complexed with cationic liposome could suppress the growth and metastasis of hepatocellular carcinoma in vivo and discover its possible mechanism of action. Apoptosis induction of pSecTag2B-vasostatin plasmid on murine endothelial cells (MS1) was examined by flow cytometric analysis in vitro. Nude mice bearing HCCLM3 tumor received pSecTag2B-vasostatin, pSecTag2B-Null, and 0.9 % NaCl solution, respectively. Tumor net weight was measured and survival time was observed. Microvessel density within tumor tissues was determined by CD31 immunohistochemistry. H&E staining of lungs and TUNEL assay of primary tumor tissues were also conducted. The results displayed that pSecTag2B-vasostatin could inhibit the growth and metastasis of hepatocellular carcinoma xenografts and prolong survival time compared with the controls in vivo. Moreover, histologic analysis revealed that pSecTag2B-vasostatin treatment increased apoptosis and inhibited angiogenesis. The present data may be of importance to the further exploration of this new anti-angiogenesis approach in the treatment of hepatocellular cancer.

Polymer nanofibers embedded with aligned gold nanorods: a new platform for plasmonic studies and optical sensing.

This paper reports the fabrication and characterization of polymer nanofibers embedded with gold nanorods in uniaxial alignment for applications in optical waveguiding and sensing. Using a waveguiding approach, we demonstrated highly efficient excitation of localized surface plasmon resonance in the embedded gold nanorods with a photon-to-plasmon-conversion efficiency as high as 70% for a single nanorod at its longitudinal resonance wavelength. On the basis of waveguiding polymer nanofibers embedded with gold nanorods, we further demonstrated compact optical humidity sensors with a response time of 110 ms and an operation optical power as low as 500 pW.

Leaching behavior and evaluation of zebrafish embryo toxicity of microplastics and phthalates in take-away plastic containers.

Take-away containers are the common food contact materials (FCMs) that are widely used in daily life. However, little is known regarding the effects of different food simulants on the pollution characteristics of microplastics derived from food containers, as well as the toxic effects of the chemical substances that are leached from them. Extracts were obtained by adding organic solvents into plastic containers (polypropylene, PP; polystyrene, PS) to simulate aqueous, alcoholic, and fatty environments. The extracted substances and their toxic effects were then assessed by counting and characterizing the resulting microplastics and performing bio-acute toxicity assays. The results demonstrated that the highest abundance of microplastics occurred in PS containers in fatty environments, which was likely due to the rough surface of the PS. In contrast, organic solvents seemed more conducive to the migration of substances. Furthermore, the PP and PS extracts in an alcohol and fatty environment have significant impacts on zebrafish embryo development, including arrhythmia, pericardial cysts, and spinal curvature.

Fractionation of lignin from rice straw using an acidified biphasic solvent system.

To obtain lignin from lignocellulosic biomass, phenoxyethanol (EPH) was employed to construct a biphasic solvent system. The concentration of EPH in this biphasic solvent system was first studied to determine a pretreatment condition for fractionation of lignin. Then, the fractionation of lignin from rice straw was performed under the conditions of temperature 130 °C, cooking time 60 min and sulfuric acid concentration 0.1 M, in 70 % aqueous EPH solvent system. The results showed that 50.97 %, 49.52 % or 82.02 % of the removed lignin with the purity of 89.04 %, 91.30 % or 84.76 % was regenerated from EPH liquor using dimethyl carbonate (DMC), dimethoxymethane (DMM) or diethyl ether (DE) as precipitant, respectively. Additionally, the weight-average molecular weight (Mw) and dispersity index (D) of the regenerated lignin decreased to 4247-4809 g/mol and 1.26-1.60 compared with that of the original lignin (5654 g/mol and 4.78). Finally, the compositional and structural characteristics of lignin, e.g., molecular weight and molecular structure, were also investigated by DSC, HSQC and elemental analysis.

Biphasic fractionation of lignocellulosic biomass based on the combined action of pretreatment severity and solvent effects on delignification.

A novel method based on pretreatment severity and solvent effects on delignification, was introduced to pretreat and fractionate lignocellulose in a 2-phenoxyethanol (EPH) biphasic solvent system. The combined severity factor (CSF) was used to regulate pretreatment severity, and the relative energy difference (RED) of solvent system to lignin was used to evaluate solvent effects. The combined action of pretreatment severity and solvent effects on delignification was first investigated by the response surface regression analysis on the pretreatment of Amorpha. Accordingly, pretreatment and fractionation of Amorpha, poplar and corn straw were then conducted under the optimized conditions. Results showed that >99 % lignin was removed after pretreatment with CSF 3.7845 in a solvent system with RED 0.9371, and 42.94 %, 39.41 % and 70.90 % lignin from Amorpha, poplar and corn straw were respectively regenerated from organosolv liquor after fractionation. Finally, the regenerated products were characterized by FTIR, TG and GPC analysis.

Chitosan-based multifunctional hydrogel for sequential wound inflammation elimination, infection inhibition, and wound healing.

In this study, a composite hydrogel (QMPD hydrogel) composed of methacrylate anhydride (MA) grafted quaternary ammonium chitosan (QCS-MA), polyvinylpyrrolidone (PVP), and dopamine (DA) was designed for the sequential wound inflammation elimination, infection inhibition, and wound healing. The QMPD hydrogel formation was initiated by the ultraviolet light-triggered polymerization of QCS-MA. Furthermore, hydrogen bonds, electrostatic interactions, and "π-π" stacking between QCS-MA, PVP, and DA were involved in the hydrogel formation. In this hydrogel, the quaternary ammonium groups of quaternary ammonium chitosan and the photothermal conversion of polydopamine are capable of killing bacteria on wounds, which showed the bacteriostatic ratios of 85.6 % and 92.5 % toward Escherichia coli and Staphylococcus aureus, respectively. Moreover, the oxidation of DA sufficiently scavenged free radicals and introduced the QMPD hydrogel with good anti-oxidant and anti-inflammatory abilities. Together with the extracellular matrix-mimic tropical structure, the QMPD hydrogel significantly promoted the wound management of mice. Therefore, the QMPD hydrogel is expected to provide a new method for the design of wound healing dressings.

[Effect of collagen sponge on the healing process of alveolar fossa after tooth extraction in rats].

PURPOSE: To investigate the effect of collagen sponge on early bone healing process of alveolar fossa after tooth extraction in rats. METHODS: A total of 16 healthy female SD rats were selected. Animal models with tooth extraction were established. The right alveolar fossa inserted with collagen sponge was as the experimental group, and the left alveolar fossa was as the control group with treatment. The rats were sacrificed 1, 2, 4 and 8 weeks after tooth extraction, and the osteogenesis of alveolar fossa was observed. Real-time quantitative PCR (qt-PCR) was used to detect the changes of osteogenesis related gene expression. SPSS 19.0 software package was used for statistical analysis. RESULTS: After surgery, alveolar cavity healing was significantly better in the experimental group than in the control group. Osterix, Runx2 and Vegf genes were expressed in the experimental group and the control group, and the expression levels of related genes in the experimental group were significantly higher than the control group 1, 2, 4 and 8 weeks after surgery(P＜0.05). CONCLUSIONS: Collagen sponge could promote early alveolar bone healing, possibly related to the expression level of osteogenic genes regulated by collagen sponge.

Genomic insight into domestication of rubber tree.

Understanding the genetic basis of rubber tree (Hevea brasiliensis) domestication is crucial for further improving natural rubber production to meet its increasing demand worldwide. Here we provide a high-quality H. brasiliensis genome assembly (1.58 Gb, contig N50 of 11.21 megabases), present a map of genome variations by resequencing 335 accessions and reveal domestication-related molecular signals and a major domestication trait, the higher number of laticifer rings. We further show that HbPSK5, encoding the small-peptide hormone phytosulfokine (PSK), is a key domestication gene and closely correlated with the major domestication trait. The transcriptional activation of HbPSK5 by myelocytomatosis (MYC) members links PSK signaling to jasmonates in regulating the laticifer differentiation in rubber tree. Heterologous overexpression of HbPSK5 in Russian dandelion (Taraxacum kok-saghyz) can increase rubber content by promoting laticifer formation. Our results provide an insight into target genes for improving rubber tree and accelerating the domestication of other rubber-producing plants.

Extensive sequence divergence between the reference genomes of Taraxacum kok-saghyz and Taraxacum mongolicum.

Plants belonging to the genus Taraxacum are widespread all over the world, which contain rubber-producing and non-rubber-producing species. However, the genomic basis underlying natural rubber (NR) biosynthesis still needs more investigation. Here, we presented high-quality genome assemblies of rubber-producing T. kok-saghyz TK1151 and non-rubber-producing T. mongolicum TM5. Comparative analyses uncovered a large number of genetic variations, including inversions, translocations, presence/absence variations, as well as considerable protein divergences between the two species. Two gene duplication events were found in these two Taraxacum species, including one common ancestral whole-genome triplication and one subsequent round of gene amplification. In genomes of both TK1151 and TM5, we identified the genes encoding for each step in the NR biosynthesis pathway and found that the SRPP and CPT gene families have experienced a more obvious expansion in TK1151 compared to TM5. This study will have large-ranging implications for the mechanism of NR biosynthesis and genetic improvement of NR-producing crops.

A multimodal antimicrobial platform based on MXene for treatment of wound infection.

Featured with a three-dimensional network structure, electrostatic spinning nanofibrous membranes can maintain the hygroscopic balance in the wound place and promote the wound healing, thus have been extensively studied as a promising wound healing dressing. In this study, amoxicillin (AMX), MXene, and polyvinyl alcohol (PVA) were mixed and electrospun into an antibacterial nanofibrous membrane (MXene-AMX-PVA nanofibrous membrane). In the composite nanofibrous membrane, the PVA matrix could control the release of AMX to combat bacterial infection, while the MXene could transform the near-infrared laser into heat, leading to local hyperthermia to promote the AMX release. Meanwhile, the local hyperthermia could also destroy the noncellular components of bacteria and synergistically cause the bacterial inactivation. The bacteriostatic activity and wound healing ability of the composite nanofibrous membrane were systematically verified on the S. aureus in vitro and the S. aureus-infected mouse skin defect model in vivo. This membrane not only functioned as a physical barrier to co-load the AMX and MXene, but also exhibited the high antibacterial and accelerated wound healing capacity, which will advance the design of novel wound healing dressings and antibacterial strategies.

Influence of wastewater treatment process on pollution characteristics and fate of microplastics.

The increasing abundance of microplastics (MPs) in rivers and oceans continues to face major challenges. In particular, MPs with smaller particle sizes are difficult to identify and quantify when they reach the environment. This study investigated four typical wastewater treatment plants (WWTPs), including urban WWTPs and industrial WWTP with different treatment technologies. The results showed that the average abundance of MPs in the influent and effluent was 538.67 ± 22.05 n/L to 1290 ± 65.26 n/L and 20.44 ± 1.19 n/L to 40.67 ± 11.12 n/L. The primary and secondary treatment processes can effectively remove MPs between 51.04% and 72.82% from wastewater. After tertiary treatments, the removal efficiency was further increased to more than 90%. The study aims to explore the removal mechanism of MPs in each stage of the wastewater treatment process and to reveal the fate of MPs in WWTPs, and help to understand their future monitoring to optimize the wastewater treatment process.

Microplastic pollution characteristic in surface water and freshwater fish of Gehu Lake, China.

Much more attention has been poured into microplastic pollution in freshwater systems recently. In the present study, the pollution of microplastics (MPs) in surface water and freshwater fish (crucian carp, etc.) were investigated from Gehu Lake, which is the second largest lake in southern Jiangsu after Taihu Lake. The result manifested that the average abundance of MPs was respectively 6.33±2.67 n/L for surface water and 10.7 items per individual for freshwater fish. The distribution of MPs in Gehu Lake varied from place to place, with the highest abundance of MPs was observed in the two estuaries of the eastern part of the lake. It was speculated that topographical factors and human factors were the main factors affecting the abundance and distribution of MPs. Transparent fibers were the main type of MPs in water samples, accounting for 69.70% of all detected particles. Meanwhile, most of the MPs ingested by freshwater fish were fibers, and the main colors were transparent and blue. In addition, the dominant size of the MPs was between 0.1 to 0.5 mm in water and fish samples. Moreover, PES, man-made fiber, and PP were the dominant polymer types in the surface water and fish samples. The results of this investigation can provide basic data for the research and management of MPs in freshwater systems.

[Effect of ipriflavone on reconstruction of periodontal tissues during recurrence of orthodontic teeth in rats].

PURPOSE: To investigate the effect of ipriflavone on reconstruction of periodontal tissues during recurrence of orthodontic teeth. METHODS: Twenty-four male SD rats were randomized into 2 groups, ipriflavone group(IP group) and control group, there were 12 rats in each group. The model of recurrence after movement of orthodontic teeth in rats was established. After continuous loading for 10 days, the loading devices were removed. Rats in ipriflavone group (IP group) were given ipriflavone intragastrically for 10 mg/(kg·d) after the devices were removed, while rats in the control group were given an equivalent amount of normal saline after the devices were removed. On the 0th, 1st, 3rd, 7th, and 10th day of administration, the rat maxillary impression and plaster model of two groups were prepared under local anesthesia, the distance between maxillary first molar lingual sulcus point and third molar in lingual groove point was measured to evaluate the relapse distance. After drug infusion for 10 days, the collected tissue specimens were stained with H-E to observe periodontal reconstruction, and expression of bone morphogenetic protein-2(BMP-2) was detected by immunohistochemical staining. Software Image-Pro 6.0 was used to analyze the optical density values of the stained sections. The data were analyzed with SPSS 22.0 software package. RESULTS: After removing the orthopaedic devices for 10 days , there was a significant recurrence of the movement of the orthodontic teeth in both groups. The recurrent distance of IP group was significantly smaller than that of the control group, and still significantly smaller than that of the control group at 10 d. H-E staining and immunohistochemical staining results showed that the IP group had more new bone formation and more BMP-2 expression in the periodontal tissues compared to the control group in vivo. CONCLUSIONS: In the process of recurrence of orthodontic tooth movement, ipriflavone can promote the expression of BMP-2 in periodontal tissue, improve bone remodeling of periodontal tissue, and effectively reduce the recurrent rate of orthodontic tooth movement.

Root shortening in patients treated with two-step and en masse space closure procedures with sliding mechanics.

OBJECTIVE: To investigate the comparative amount of root shortening between two-step and en masse space closure procedures. MATERIALS AND METHODS: Fifty-two patients were selected from a pool of patients satisfying the following inclusion criteria: no evidence of resorption on the pretreatment panoramic radiographs; no dental trauma; no dilacerations of incisor roots, anodontia, or impacted canines; complete root formation at the start of treatment; intact and caries-free incisors; no endodontically treated incisors; Angle Class I or II malocclusion; extraction of four first premolars; and space closure with moderate anchorage. Patients received treatment with either a two-step or an en masse procedure to close the extraction spaces after alignment and leveling with the same preadjusted appliances. Root shortening of the maxillary and mandibular incisors was evaluated on panoramic radiographs, taken before and after space closure, and measured in millimeters. Distortion of measurements caused by panoramic radiographs was corrected by using special metal rods ligated to brackets. Statistical comparisons of root shortening between space closure procedures were investigated with the two-sample t test. RESULTS: No difference was found in the amount of root shortening between space closure procedures. The average root shortening of maxillary central and lateral incisors was 0.43 +/- 0.12 mm and 0.58 +/- 0.10 mm, respectively, and that of mandibular central and lateral incisors was 0.23 +/- 0.07 mm and 0.22 +/- 0.06 mm, respectively. CONCLUSION: No difference should be expected in root resorption between two-step and en masse space closure procedure.

The effects of binge alcohol exposure on tooth movement and associated root resorption in rats.

BACKGROUND: Considering the increasing prevalence of alcohol use and the growing number of orthodontic patients, some orthodontic patients might engage in binge drinking during treatment. Nevertheless, little is known about the effect of alcohol use on orthodontic treatment. METHODS: Male Wistar rats were divided into ethanol and control groups (n = 32). The rats received a single daily intraperitoneal injection of 20% (vol/vol) ethanol/saline solution at a dose of 3 g/kg of ethanol or saline for three consecutive days, and no injection was given during the remaining four days each week. All rats received orthodontic appliances to draw the maxillary first molar mesially. The rats were sacrificed at days 14 and 28, respectively. The amount of tooth movement was measured. Root resorption area was evaluated by scanning electron microscope. Hematoxylin and eosin (H&E) staining and tartrate-resistant acid phosphatase (TRAP) staining were conducted. Immunohistochemistry staining was performed to evaluate the expressions of nuclear factor kappa B ligand (RANKL), osteoprotegerin (OPG), and inducible nitric oxide synthase (iNOS). RESULTS: There were no significant differences in tooth movement and root resorption between ethanol and control groups. The number of TRAP-positive cells was significantly higher in the ethanol group. The expression of RANKL was statistically increased in the ethanol group. In contrast, the expression of OPG was remarkably decreased in rats injected with ethanol. Moreover, the iNOS level was significantly up-regulated in the ethanol group. CONCLUSION: The tooth movement and root resorption in rats were not affected by binge alcohol exposure.